WorldWideScience

Sample records for internal tracer method

  1. Proceedings of Tracer 3. International Conference on Tracers and Tracing Methods

    International Nuclear Information System (INIS)

    2004-01-01

    Tracer 3 conference is a continuation of former Tracer 1 (1998) and Tracer 2 (2001) conferences organized by CNRS - Nancy France. The objective of this 3rd conference is presentation of different aspects of tracer method applications and development of tracer methodology.The new field of activity presented at the Conference was application of stable isotopes as natural tracers for investigations of environmental processes. The conference gave the possibility for scientific information exchange between specialists from different fields of activity such as chemical engineering, chemistry, bioengineering, environmental engineering, hydrology, civil engineering, metallurgy, etc. The presentations were divided into groups covering the principal items of Conference. Section A. Fundamental development - RTD and tracer methodology, - RTD methodology and Computational Fluid Dynamics (CFD), - New tracers and detectors. Section B. Industrial applications - Environment, - Geology, hydrogeology and oil field applications, - Civil engineering, mineral engineering and metallurgy applications, - Food engineering and bioengineering, - Material engineering, - Chemical engineering. During the Conference INIS promotion materials were exposed by INIS liaison officer for Poland

  2. Proceedings of Tracer 3. International Conference on Tracers and Tracing Methods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Tracer 3 conference is a continuation of former Tracer 1 (1998) and Tracer 2 (2001) conferences organized by CNRS - Nancy France. The objective of this 3rd conference is presentation of different aspects of tracer method applications and development of tracer methodology.The new field of activity presented at the Conference was application of stable isotopes as natural tracers for investigations of environmental processes. The conference gave the possibility for scientific information exchange between specialists from different fields of activity such as chemical engineering, chemistry, bioengineering, environmental engineering, hydrology, civil engineering, metallurgy, etc. The presentations were divided into groups covering the principal items of Conference. Section A. Fundamental development - RTD and tracer methodology, - RTD methodology and Computational Fluid Dynamics (CFD), - New tracers and detectors. Section B. Industrial applications - Environment, - Geology, hydrogeology and oil field applications, - Civil engineering, mineral engineering and metallurgy applications, - Food engineering and bioengineering, - Material engineering, - Chemical engineering. During the Conference INIS promotion materials were exposed by INIS liaison officer for Poland.

  3. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  4. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  5. Tracers and Tracer Testing: Design, Implementation, Tracer Selection, and Interpretation Methods

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Shook; Shannon L.; Allan Wylie

    2004-01-01

    Conducting a successful tracer test requires adhering to a set of steps. The steps include identifying appropriate and achievable test goals, identifying tracers with the appropriate properties, and implementing the test as designed. When these steps are taken correctly, a host of tracer test analysis methods are available to the practitioner. This report discusses the individual steps required for a successful tracer test and presents methods for analysis. The report is an overview of tracer technology; the Suggested Reading section offers references to the specifics of test design and interpretation.

  6. Chemical Tracer Methods: Chapter 7

    Science.gov (United States)

    Healy, Richard W.

    2017-01-01

    Tracers have a wide variety of uses in hydrologic studies: providing quantitative or qualitative estimates of recharge, identifying sources of recharge, providing information on velocities and travel times of water movement, assessing the importance of preferential flow paths, providing information on hydrodynamic dispersion, and providing data for calibration of water flow and solute-transport models (Walker, 1998; Cook and Herczeg, 2000; Scanlon et al., 2002b). Tracers generally are ions, isotopes, or gases that move with water and that can be detected in the atmosphere, in surface waters, and in the subsurface. Heat also is transported by water; therefore, temperatures can be used to trace water movement. This chapter focuses on the use of chemical and isotopic tracers in the subsurface to estimate recharge. Tracer use in surface-water studies to determine groundwater discharge to streams is addressed in Chapter 4; the use of temperature as a tracer is described in Chapter 8.Following the nomenclature of Scanlon et al. (2002b), tracers are grouped into three categories: natural environmental tracers, historical tracers, and applied tracers. Natural environmental tracers are those that are transported to or created within the atmosphere under natural processes; these tracers are carried to the Earth’s surface as wet or dry atmospheric deposition. The most commonly used natural environmental tracer is chloride (Cl) (Allison and Hughes, 1978). Ocean water, through the process of evaporation, is the primary source of atmospheric Cl. Other tracers in this category include chlorine-36 (36Cl) and tritium (3H); these two isotopes are produced naturally in the Earth’s atmosphere; however, there are additional anthropogenic sources of them.

  7. Methods for conduct of atmospheric tracer studies at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Stone, D J.M.; Pascoe, J H [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Division

    2000-07-01

    A perfluorocarbon atmospheric tracer system has been developed to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. This report discusses the tracer release, sampling and analysis methods.

  8. Methods of 15N tracer research in biological systems

    International Nuclear Information System (INIS)

    Hirschberg, K.; Faust, H.

    1985-01-01

    The application of the stable isotope 15 N is of increasing importance in different scientific disciplines, especially in medicine, agriculture, and the biosciences. The close correlation between the growing interest and improvements of analytical procedures resulted in remarkable advances in the 15 N tracer technique. On the basis of the latest results of 15 N tracer research in life sciences and agriculture methods of 15 N tracer research in biological systems are compiled. The 15 N methodology is considered under three headings: Chemical analysis with a description of methods of sample preparation (including different separation and isolation methods for N-containing substances of biological and agricultural origin) and special procedures converting ammonia to molecular nitrogen. Isotopic analysis with a review on the most important methods of isotopic analysis of nitrogen: mass spectrometry (including the GC-MS technique), emission spectrometry, NMR spectroscopy, and other analytical procedures. 15 N-tracer techniques with a consideration of the role of the isotope dilution analysis as well as different labelling techniques and the mathematical interpretation of tracer data (modelling, N turnover experiments). In these chapters also sources of errors in chemical and isotopic analysis, the accuracy of the different methods and its importance on tracer experiments are discussed. Procedures for micro scale 15 N analysis and aspects of 15 N analysis on the level of natural abundance are considered. Furthermore some remarks on isotope effects in 15 N tracer experiments are made. (author)

  9. Tracer preparate and method for its production

    International Nuclear Information System (INIS)

    Pratt, F.P.; Gagnon, D.

    1978-01-01

    The injectable tracer preparate for investigations to determine the blood flow in organs or the effect of drugs on the blood flow consists of a core of ion exchanger resin coated with polyfuran or a polymer which is the reaction product of a monomer catalysable by acid or base. The nuclei have a diameter of 10 to 200 micron, the coating thickness is between 1 and 3 micron. Ions of Ce 141, Cr 51, Sr 85, Sr 46 or Co 57 of strength 0.1-100 millicurie are adsorbed on the nucleus. (DG) [de

  10. Emission quantification using the tracer gas dispersion method: The influence of instrument, tracer gas species and source simulation

    DEFF Research Database (Denmark)

    Delre, Antonio; Mønster, Jacob; Samuelsson, Jerker

    2018-01-01

    The tracer gas dispersion method (TDM) is a remote sensing method used for quantifying fugitive emissions by relying on the controlled release of a tracer gas at the source, combined with concentration measurements of the tracer and target gas plumes. The TDM was tested at a wastewater treatment...... plant for plant-integrated methane emission quantification, using four analytical instruments simultaneously and four different tracer gases. Measurements performed using a combination of an analytical instrument and a tracer gas, with a high ratio between the tracer gas release rate and instrument...... precision (a high release-precision ratio), resulted in well-defined plumes with a high signal-to-noise ratio and a high methane-to-tracer gas correlation factor. Measured methane emission rates differed by up to 18% from the mean value when measurements were performed using seven different instrument...

  11. Methods and systems using encapsulated tracers and chemicals for reservoir interrogation and manipulation

    Science.gov (United States)

    Roberts, Jeffery; Aines, Roger D; Duoss, Eric B; Spadaccini, Christopher M

    2014-11-04

    An apparatus, method, and system of reservoir interrogation. A tracer is encapsulating in a receptacle. The receptacle containing the tracer is injected into the reservoir. The tracer is analyzed for reservoir interrogation.

  12. A Systematic Method For Tracer Test Analysis: An Example Using Beowawe Tracer Data

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Shook

    2005-01-01

    Quantitative analysis of tracer data using moment analysis requires a strict adherence to a set of rules which include data normalization, correction for thermal decay, deconvolution, extrapolation, and integration. If done correctly, the method yields specific information on swept pore volume, flow geometry and fluid velocity, and an understanding of the nature of reservoir boundaries. All calculations required for the interpretation can be done in a spreadsheet. The steps required for moment analysis are reviewed in this paper. Data taken from the literature is used in an example calculation.

  13. Contributions to hydrological tracer methods and their application

    International Nuclear Information System (INIS)

    1982-04-01

    The activities of the Institut fuer Radiohydrometrie of the GSF are mainly devoted to the field of environmental research studying the quality, use and protection from pollution of drinking water which has become scarce in many parts of the world. The knowledge and experience of a variety of scientific disciplines are combined to the common task of developing new tracer methods and selecting suitable hydrogeological methods to allow quantitative studies of the hydrological cycle, from rainfall to surface or sub-surface run-off. The tracers used in these studies are for the most part stable, natural radioisotopes occurring in the hydrological cycle, as well as fluorescent dyes or radionuclides for water labelling. The contributions collected in this volume are grouped according to the above outline of tasks and present a survey of current methods and measurements, illustrating their efficiency in solving hydrological problems. (orig./RW) [de

  14. Tracer Methods for Characterizing Fracture Creation in Engineered Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Peter [Energy & Geoscience Institute at the University of Utah, Salt Lake City, UT (United States); Harris, Joel [Univ. of Utah, Salt Lake City, UT (United States)

    2014-05-08

    The aim of this proposal is to develop, through novel high-temperature-tracing approaches, three technologies for characterizing fracture creation within Engineered Geothermal Systems (EGS). The objective of a first task is to identify, develop and demonstrate adsorbing tracers for characterizing interwell reservoir-rock surface areas and fracture spacing. The objective of a second task is to develop and demonstrate a methodology for measuring fracture surface areas adjacent to single wells. The objective of a third task is to design, fabricate and test an instrument that makes use of tracers for measuring fluid flow between newly created fractures and wellbores. In one method of deployment, it will be used to identify qualitatively which fractures were activated during a hydraulic stimulation experiment. In a second method of deployment, it will serve to measure quantitatively the rate of fluid flowing from one or more activated fracture during a production test following a hydraulic stimulation.

  15. Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, Melissa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Heredia, Elizabeth [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cohn, Sebastian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Logue, Jennifer [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-01

    This report documents experiments performed in three homes to assess the methodology used to determine air exchange rates using passive tracer techniques. The experiments used four different tracer gases emitted simultaneously but implemented with different spatial coverage in the home. Two different tracer gas sampling methods were used. The results characterize the factors of the execution and analysis of the passive tracer technique that affect the uncertainty in the calculated air exchange rates. These factors include uncertainties in tracer gas emission rates, differences in measured concentrations for different tracer gases, temporal and spatial variability of the concentrations, the comparison between different gas sampling methods, and the effect of different ventilation conditions.

  16. Waste tank ventilation rates measured with a tracer gas method

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Evans, J.C.; Sklarew, D.S.; Mitroshkov, A.V.

    1998-08-01

    Passive ventilation with the atmosphere is used to prevent accumulation of waste gases and vapors in the headspaces of 132 of the 177 high-level radioactive waste Tanks at the Hanford Site in Southeastern Washington State. Measurements of the passive ventilation rates are needed for the resolution of two key safety issues associated with the rates of flammable gas production and accumulation and the rates at which organic salt-nitrate salt mixtures dry out. Direct measurement of passive ventilation rates using mass flow meters is not feasible because ventilation occurs va multiple pathways to the atmosphere (i.e., via the filtered breather riser and unsealed tank risers and pits), as well as via underground connections to other tanks, junction boxes, and inactive ventilation systems. The tracer gas method discussed in this report provides a direct measurement of the rate at which gases are removed by ventilation and an indirect measurement of the ventilation rate. The tracer gas behaves as a surrogate of the waste-generated gases, but it is only diminished via ventilation, whereas the waste gases are continuously released by the waste and may be subject to depletion mechanisms other than ventilation. The fiscal year 1998 tracer studies provide new evidence that significant exchange of air occurs between tanks via the underground cascade pipes. Most of the single-shell waste tanks are connected via 7.6-cm diameter cascade pipes to one or two adjacent tanks. Tracer gas studies of the Tank U-102/U-103 system indicated that the ventilation occurring via the cascade line could be a significant fraction of the total ventilation. In this two-tank cascade, air evidently flowed from Tank U-103 to Tank U-102 for a time and then was observed to flow from Tank U-102 to Tank U-103

  17. Natural tracer test simulation by stochastic particle tracking method

    International Nuclear Information System (INIS)

    Ackerer, P.; Mose, R.; Semra, K.

    1990-01-01

    Stochastic particle tracking methods are well adapted to 3D transport simulations where discretization requirements of other methods usually cannot be satisfied. They do need a very accurate approximation of the velocity field. The described code is based on the mixed hybrid finite element method (MHFEM) to calculated the piezometric and velocity field. The random-walk method is used to simulate mass transport. The main advantages of the MHFEM over FD or FE are the simultaneous calculation of pressure and velocity, which are considered as unknowns; the possibility of interpolating velocities everywhere; and the continuity of the normal component of the velocity vector from one element to another. For these reasons, the MHFEM is well adapted for particle tracking methods. After a general description of the numerical methods, the model is used to simulate the observations made during the Twin Lake Tracer Test in 1983. A good match is found between observed and simulated heads and concentrations. (Author) (12 refs., 4 figs.)

  18. In-situ testing methods using radioactive tracers

    International Nuclear Information System (INIS)

    Sauzay, G.

    1976-01-01

    Some typical applications of tracer techniques in hydrology are presented: study of the extraction of sands and gravels in a estuary; in-situ study of the transport of sediments by the swell at a depth ranging from 8 to 22m; study of the transport of sands on the site Bonne Anse - Saint Palais [fr

  19. Device and method for traditional chinese medicine diagnosis using radioactive tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shanling; Shen, Miaohe

    1997-05-29

    Disclosed is a device and method for traditional chinese medicine diagnosis using radioactive-tracer method. At least two nuclear radiation probes are arranged apart along the channels to detect the changing with time and on space of the intensity of radioactivity of the nuclear radioactive tracer which has been injected into the body in the channel position. The detected signals are amplified by amplifiers, and the outputs of the amplifiers are applied to data processing means which monitor the whole detecting process in real time and analyse and process the detected information about the changing of the intensity of radioactivity with time and on space indicating the operating of vital energy and blood, and obtain state parameters about operating of vital energy and blood in the body which is then output through data output means. (author) figs.

  20. Determination of the Absolute Disintegration Rate of Cs-137 sources by the Tracer Method

    Energy Technology Data Exchange (ETDEWEB)

    Hellstroem, S; Brune, D

    1963-07-15

    {sup 137}Cs - sources were absolutely measured by the 'tracer method', with {sup 82}Br as a tracer nuclide and with application of the 4{pi} {beta}-{gamma} coincidence technique. A self-absorption of 6 % was found in sources obtained from a solution with a carrier-content of 400 {mu}g/ml. The precision of the method for the determination of the {beta}-emission rate was estimated to {+-} 1 %. The results were compared with those of other works.

  1. An injected gamma-tracer method for soil-moisture movement investigations in arid zones

    International Nuclear Information System (INIS)

    Nair, A.R.; Navada, S.V.; Rao, S.M.

    1980-01-01

    A method for the in-situ determination of soil-moisture transport rates using K 3 60 Co(CN) 6 is discussed. The tracer compares well with tritiated water in laboratory investigations and the results obtained in limited field studies are very encouraging. The method promises to be of specific interest in arid-zone investigations where the soil-moisture fluxes in liquid and vapour phases could cause complications for tritium tracer data interpretation. (author)

  2. Determination of the Absolute Disintegration Rate of Cs-137 sources by the Tracer Method

    International Nuclear Information System (INIS)

    Hellstroem, S.; Brune, D.

    1963-07-01

    137 Cs - sources were absolutely measured by the 'tracer method', with 82 Br as a tracer nuclide and with application of the 4π β-γ coincidence technique. A self-absorption of 6 % was found in sources obtained from a solution with a carrier-content of 400 μg/ml. The precision of the method for the determination of the β-emission rate was estimated to ± 1 %. The results were compared with those of other works

  3. Acupuncture meridians demythified. A study using the radioactive tracer method

    International Nuclear Information System (INIS)

    Simon, J.; Esquerre, J.P.; Guiraud, R.; Guiraud, G.; Lazorthes, Y.

    1988-01-01

    Radioactive trajectories can be visualized by injecting a radioactive tracer, technetium 99 m, at the site of acupuncture points. To determine the exact nature of these trajectories we performed several experiments on healthy volunteers, and our results may be summarized as follows. The target organs of technetium 99 m, and notably the thyroid gland, were always visualized. The circulating radioactivity, visible on scintiscans and confirmed by venous blood counts, was not negligible. The radioactive trajectories we observed were often divided at their starting point and did not extend along the whole length of the acupuncture meridians they might have made visible. The radioactive trajectories disappeared after venous blockade to reappear when the blockade was lifted. Finally, the radioactive trajectories obtained were very similar after injection at the acupuncture point and at a control point. These findings indicate a lymphatic and venous drainage of the radioactive tracer at the site of injection followed by transportation through the veins, rather than visualization of acupuncture meridians as suggested by some authors [fr

  4. Acupuncture meridians demythified. A study using the radioactive tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J.; Esquerre, J.P.; Guiraud, R.; Guiraud, G.; Lazorthes, Y.

    1988-07-01

    Radioactive trajectories can be visualized by injecting a radioactive tracer, technetium 99 m, at the site of acupuncture points. To determine the exact nature of these trajectories we performed several experiments on healthy volunteers, and our results may be summarized as follows. The target organs of technetium 99 m, and notably the thyroid gland, were always visualized. The circulating radioactivity, visible on scintiscans and confirmed by venous blood counts, was not negligible. The radioactive trajectories we observed were often divided at their starting point and did not extend along the whole length of the acupuncture meridians they might have made visible. The radioactive trajectories disappeared after venous blockade to reappear when the blockade was lifted. Finally, the radioactive trajectories obtained were very similar after injection at the acupuncture point and at a control point. These findings indicate a lymphatic and venous drainage of the radioactive tracer at the site of injection followed by transportation through the veins, rather than visualization of acupuncture meridians as suggested by some authors.

  5. Investigation by tracer method of water balance in filling the gob with slurries

    International Nuclear Information System (INIS)

    Jureczko, J.; Skowronek, E.

    1977-01-01

    Results of investigations on the establishment of conditions of water flow in filling old workings with mud, in order to determine the degree of water hazard for mine workings in one of mines are given. For the inspection of flow, the stable tracer method and the neutron activation analysis were used. Chromium as a complex compound with EDTA was used as tracer. Geological and mining conditions in the area of investigations by tracers are given and the disposal of diluted stowing slurry is characterized. The method of interpretation of results is discussed in order to determine the water flow rate in the gob and to draw up the water balance on the basis of the curve of tracer travel. (author)

  6. Fluorescence characteristics of the fuel tracers triethylamine and trimethylamine for the investigation of fuel distribution in internal combustion engines.

    Science.gov (United States)

    Lind, Susanne; Aßmann, Simon; Zigan, Lars; Will, Stefan

    2016-03-01

    Laser-induced fluorescence based on fuel tracers like amines is a suitable measurement technique for mixing studies in internal combustion (IC) engines. Triethylamine has often been used in gasoline IC engines; however, no detailed fluorescence characterization for excitation at 263 or 266 nm is available. Trimethylamine (TMA) exhibits high potential as a gaseous fuel tracer but little information about TMA fluorescence is currently available. A picosecond laser source combined with a streak camera equipped with a spectrograph was used to determine the spectral fluorescence emission and fluorescence decay time of both tracers. The tracers were investigated at various temperatures and pressures in a calibration cell with nitrogen as bath gas. The results provide an in-depth understanding of the fluorescence characteristics of both tracers and allow assessment of their application to the investigation of fuel distribution in IC engines.

  7. Flow-rate measurement using radioactive tracers and transit time method

    International Nuclear Information System (INIS)

    Turtiainen, Heikki

    1986-08-01

    The transit time method is a flow measurement method based on tracer techniques. Measurement is done by injecting to the flow a pulse of tracer and measuring its transit time between two detection positions. From the transit time the mean flow velosity and - using the pipe cross section area - the volume flow rate can be calculated. When a radioisotope tracer is used the measurement can be done from outside the pipe and without disturbing the process (excluding the tracer injection). The use of the transit time method has been limited because of difficulties associated with handling and availability of radioactive tracers and lack of equipment suitable for routine use in industrial environments. The purpose of this study was to find out if these difficulties may be overcome by using a portable isotope generator as a tracer source and automating the measurement. In the study a test rig and measuring equipment based on the use of a ''1''3''7Cs/''1''3''7''''mBa isotope generator were constructed. They were used to study the accuracy and error sources of the method and to compare different algorithms to calculate the transit time. The usability of the method and the equipment in industrial environments were studied by carrying out over 20 flow measurements in paper and pulp mills. On the basis of the results of the study, a project for constructing a compact radiatracer flowmeter for industrial use has been started. The application range of this kind of meter is very large. The most obvious applications are in situ calibration of flowmeters, material and energy balance studies, process equipment analyses (e.g. pump efficiency analyses). At the moment tracer techniques are the only methods applicable to these measurements on-line and with sufficient accuracy

  8. Tracer theory

    International Nuclear Information System (INIS)

    Margrita, R.

    1988-09-01

    Tracers are used in many fields of science to investigate mass transfer. The scope of tracers applications in Service of Applications Radioisotopes (S.A.R.-France) is large and concerns natural and industrial systems such as Sciences of earth: hydrology - civil engineering - Sedimentology - environmental studies. Industrial field: chemical engineering - mechanical engineering. A general tracer methodology has been developed in our laboratories from these different applications fields and this paper shows these different points of view in using tracers; our wish is that the methods used in an experimental field can be employed in an another one

  9. Double tracer autoradiographic method for sequential evaluation of regional cerebral perfusion

    International Nuclear Information System (INIS)

    Matsuda, H.; Tsuji, S.; Oba, H.; Kinuya, K.; Terada, H.; Sumiya, H.; Shiba, K.; Mori, H.; Hisada, K.; Maeda, T.

    1989-01-01

    A new double tracer autoradiographic method for the sequential evaluation of altered regional cerebral perfusion in the same animal is presented. This method is based on the sequential injection of two tracers, 99m Tc-hexamethylpropyleneamine oxime and N-isopropyl-( 125 I)p-iodoamphetamine. This method is validated in the assessment of brovincamine effects on regional cerebral perfusion in an experimental model of chronic brain ischemia in the rat. The drug enhanced perfusion recovery in low-flow areas, selectively in surrounding areas of infarction. The results suggest that this technique is of potential use in the study of neuropharmacological effects applied during the experiment

  10. Single well surfactant test to evaluate surfactant floods using multi tracer method

    Science.gov (United States)

    Sheely, Clyde Q.

    1979-01-01

    Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.

  11. Use of a variable tracer infusion method to determine glucose turnover in humans

    International Nuclear Information System (INIS)

    Molina, J.M.; Baron, A.D.; Edelman, S.V.; Brechtel, G.; Wallace, P.; Olefsky, J.M.

    1990-01-01

    The single-compartment pool fraction model, when used with the hyperinsulinemic glucose clamp technique to measure rates of glucose turnover, sometimes underestimates true rates of glucose appearance (Ra) resulting in negative values for hepatic glucose output (HGO). We focused our attention on isotope discrimination and model error as possible explanations for this underestimation. We found no difference in [3-3H] glucose specific activity in samples obtained simultaneously from the femoral artery and vein (2,400 +/- 455 vs. 2,454 +/- 522 dpm/mg) in 6 men during a hyperinsulinemic euglycemic clamp study where insulin was infused at 40 mU.m-2.min-1 for 3 h; therefore, isotope discrimination did not occur. We compared the ability of a constant (0.6 microCi/min) vs. variable tracer infusion method (tracer added to the glucose infusate) to measure non-steady-state Ra during hyperinsulinemic clamp studies. Plasma specific activity fell during the constant tracer infusion studies but did not change from base line during the variable tracer infusion studies. By maintaining a constant plasma specific activity the variable tracer infusion method eliminates uncertainty about changes in glucose pool size. This overcame modeling error and more accurately measures non-steady-state Ra (P less than 0.001 by analysis of variance vs. constant infusion method). In conclusion, underestimation of Ra determined isotopically during hyperinsulinemic clamp studies is largely due to modeling error that can be overcome by use of the variable tracer infusion method. This method allows more accurate determination of Ra and HGO under non-steady-state conditions

  12. Tracers application method for the quantitative determination of the source of oxygenic inclusions in steel

    International Nuclear Information System (INIS)

    Rewienska-Kosciukowa, B.; Dalecki, W.; Michalik, J.S.

    1976-01-01

    The sense and the possibility of radioactive and nonradioactive isotopic tracers application in investigations of the origin of oxygenic nonmetalic inclusions is presented. The discussed methods touch the investigations such as the origin of egzogenic inclusions which passed from external sources (fireproof lining, slag) to the steel or as the endogenic ones formed during the process of steel deoxidisation. The question of the tracers choice for refractory material and the further investigations concerned the determination of the origin of nonmetallic inclusions are discussed. The question of so called isotopic replacement tracers for the main steel deoxidizing agents is considered. The criterion of determination of oxygenic inclusions formed during the process of steel deoxidization is also discussed. Several results of laboratory and industrial investigations and also the examples of application of the discussed methods in the industrial scale are presented. (author)

  13. Single-well tracer methods for hydrogeologic evaluation of target aquifers

    International Nuclear Information System (INIS)

    Hall, S.H.

    1994-11-01

    Designing an efficient well field for an aquifer thermal energy storage (ATES) project requires measuring local groundwater flow parameters as well as estimating horizontal and vertical inhomogeneity. Effective porosity determines the volume of aquifer needed to store a given volume of heated or chilled water. Ground-water flow velocity governs the migration of the thermal plume, and dispersion and heat exchange along the flow path reduces the thermal intensity of the recovered plume. Stratigraphic variations in the aquifer will affect plume dispersion, may bias the apparent rate of migration of the plume, and can prevent efficient hydraulic communication between wells. Single-well tracer methods using a conservative flow tracer such as bromide, along with pumping tests and water-level measurements, provide a rapid and cost-effective means for estimating flow parameters. A drift-and-pumpback tracer test yields effective porosity and flow velocity. Point-dilution tracer testing, using new instrumentation for downhole tracer measurement and a new method for calibrating the point-dilution test itself, yields depth-discrete hydraulic conductivity as it is affected by stratigraphy, and can be used to estimate well transmissivity. Experience in conducting both drift-and-pumpback and point-dilution tests at three different test sites has yielded important information that highlights both the power and the limitations of the single-well tracer methods. These sites are the University of Alabama Student Recreation Center (UASRC) ATES well field and the VA Medical Center (VA) ATES well field, both located in Tuscaloosa, Alabama, and the Hanford bioremediation test site north of Richland, Washington

  14. Local study of pollutants dispersion by a real time tracer method

    International Nuclear Information System (INIS)

    Faivre-Pierret, R.X.; Sestier-Carlin, R.; Berne, P.

    1992-01-01

    It is possible to use a Gaussian mathematical model of atmospheric dispersion for calculating atmospheric transfer coefficient (ATC) in long range model, but for proximity models, an experimental model using a tracer technic has to take in account ground effects and natural or artificial obstacles. SF 6 tracer method gives the true plume ground trace in real time. The measured ATC shows a larger ground trace, lower concentration in the axis, and a displacement of the maximum concentration with regard to wind axis in comparison with the calculated ATC. (A.B.). 14 refs., 4 figs., 1 tab

  15. Count rate balance method of measuring sediment transport of sand beds by radioactive tracers

    International Nuclear Information System (INIS)

    Sauzay, G.

    1968-01-01

    Radioactive tracers are applied to the direct measurement of the sediment transport rate of sand beds. The theoretical measurement formula is derived: the variation of the count rate balance is inverse of that of the transport thickness. Simultaneously the representativeness of the tracer is critically studied. The minimum quantity of tracer which has to be injected in order to obtain a correct statistical definition of count rate given by a low number of grains 'seen' by the detector is then studied. A field experiment was made and has let to study the technological conditions for applying this method: only the treatment of results is new, the experiment itself is carried out with conventional techniques applied with great care. (author) [fr

  16. Novel S-35 Intrinsic Tracer Method for Determining Groundwater Travel Time near Managed Aquifer Recharge Facilities

    Science.gov (United States)

    Urióstegui, S. H.; Bibby, R. K.; Esser, B. K.; Clark, J. F.

    2013-12-01

    Identifying groundwater travel times near managed aquifer recharge (MAR) facilities is a high priority for protecting public and environmental health. For MAR facilities in California that incorporate tertiary wastewater into their surface-spreading recharge practices, the target subsurface residence time is >9 months to allow for the natural inactivation and degradation of potential contaminants (less time is needed for full advanced treated water). Established intrinsic groundwater tracer techniques such as tritium/helium-3 dating are unable to resolve timescales of method using a naturally occurring radioisotope of sulfur, sulfur-35 (S-35). After its production in the atmosphere by cosmic ray interaction with argon, S-35 enters the hydrologic cycle as dissolved sulfate through precipitation The short half-life of S-35 (3 months) is ideal for investigating recharge and transport of MAR groundwater on the method, however, has not been applied to MAR operations because of the difficulty in measuring S-35 with sufficient sensitivity in high-sulfate waters. We have developed a new method and have applied it at two southern California MAR facilities where groundwater travel times have previously been characterized using deliberate tracers: 1) Rio Hondo Spreading Grounds in Los Angeles County, and 2) Orange County Groundwater Recharge Facilities in Orange County. Reasonable S-35 travel times of method also identified seasonal patterns in subsurface travel times, which may not be revealed by a deliberate tracer study that is dependent on the hydrologic conditions during the tracer injection period.

  17. Evaluation of single- and dual-porosity models for reproducing the release of external and internal tracers from heterogeneous waste-rock piles.

    Science.gov (United States)

    Blackmore, S; Pedretti, D; Mayer, K U; Smith, L; Beckie, R D

    2018-05-30

    Accurate predictions of solute release from waste-rock piles (WRPs) are paramount for decision making in mining-related environmental processes. Tracers provide information that can be used to estimate effective transport parameters and understand mechanisms controlling the hydraulic and geochemical behavior of WRPs. It is shown that internal tracers (i.e. initially present) together with external (i.e. applied) tracers provide complementary and quantitative information to identify transport mechanisms. The analysis focuses on two experimental WRPs, Piles 4 and Pile 5 at the Antamina Mine site (Peru), where both an internal chloride tracer and externally applied bromide tracer were monitored in discharge over three years. The results suggest that external tracers provide insight into transport associated with relatively fast flow regions that are activated during higher-rate recharge events. In contrast, internal tracers provide insight into mechanisms controlling solutes release from lower-permeability zones within the piles. Rate-limited diffusive processes, which can be mimicked by nonlocal mass-transfer models, affect both internal and external tracers. The sensitivity of the mass-transfer parameters to heterogeneity is higher for external tracers than for internal tracers, as indicated by the different mean residence times characterizing the flow paths associated with each tracer. The joint use of internal and external tracers provides a more comprehensive understanding of the transport mechanisms in WRPs. In particular, the tracer tests support the notion that a multi-porosity conceptualization of WRPs is more adequate for capturing key mechanisms than a dual-porosity conceptualization. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Standardized 15N tracer method for the determination of parameters of the whole-body protein metabolism in clinical practice

    International Nuclear Information System (INIS)

    Junghans, P.; Jung, K.; Matkowitz, R.

    1984-01-01

    A standardized 15 N tracer method is described for the assessment of nitrogen and protein metabolism in healthy and pathological changed organisms. The method represents an isotope technical procedure for the application in clinical research and practice. The clinical preparation of the patient/proband by means of a standardized nutritional regime, the tracer administration (single dose) and the sampling (urine, blood), the 15 N tracer technique (sample chemistry, emissionsspectrometric isotope analysis) and the mathematical evaluation of 15 N tracer data are described. (author)

  19. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

    2011-07-01

    The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel

  20. Principles of the tracer method in assessing regional blood flow

    International Nuclear Information System (INIS)

    Potchen, E.J.; Siegel, B.; Meidinger, R.

    1972-01-01

    The standard brain scan is abnormal when there is relative increase in blood volume or when there is an abnormal permeability to substances which normally cannot enter the brain tissue. The usual mechanism of abnormal permeability is based upon neovascularity in tissues which do not maintain the tight junctions one sees in the normal brain endothelium. These tight junctions prohibit the leakage of materials from the intra- to extravascular space, and when they are not available many materials can readily transit into the abnormal tissue substance and can therefore be discerned on a standard brain scan. In many instances, however, there is no gross breakdown in this blood-brain barrier, but more subtle derangement may be detected by determining changes in regional brain blood volume or the relative volume of distribution of various labeled materials. We have studied whether or not we can discern differences in brain spaces of two isotopes in experimental situations where the brain scan would be normal. For these models, we have used water-induced brain edema and triethyl-tin-induced brain edema in the experimental animal. In water intoxication, there is no difference in the microvascular anatomy or change in the 99 /sup m/Tc pertechnetate space, but it is apparent from our studies that the brain swells at the expense of brain blood volume and by measuring brain blood volume against brain mass, i.e., transit of 131 I antipyrine versus 51 Cr labeled red cells, one can detect brain edema in a situation where the brain scan would be normal. It is these approaches with cameras and computers using dual energies that may afford a more simplified estimation of altered regional brain function than is now available with the internal carotid injection technique. (U.S.)

  1. Retrograde trafficking of tracer protein by the internal ovarian epithelium in gravid goodeid teleosts.

    Science.gov (United States)

    Schindler, J F

    1990-02-01

    Gravid goodeid females harbor embryos in a preformed ovarian cavity for prolonged periods of gestation. Various nutrients for embryonic growth are provided by the internal ovarian epithelium (IOE). Its cells flatten during late stages of gestation and form an attenuated layer of cytoplasm covering a dense network of protruding capillaries, with the nuclear domains mostly recessing between the vascular meshes. The IOE in both Xenotoca eiseni and Girardinichthys viviparus exhibit morphological features associated with vesicular transport of macromolecules. The amounts of rough endoplasmic reticulum in the IOE cells seem insufficient to effectively synthesise proteinaceous secretions. Apparently, it rather serves as a transit route for serum-derived products. Cationized ferritin (CF) was injected into the ovarian cavity of gravid females. The electrostatic ligand spotwise attached to the luminal surface of the IOE and gained access by adsorptive micropinocytosis. Many tracer molecules were sequestered into lysosome-like vacuoles that became increasingly swollen after prolonged incubation intervals. In addition, CF traversed the IOE within small vesicles. At the basal pole of the cells the contents of transcytotic vesicles were evacuated, and localization of small CF-clusters was regularly in the basement lamina, in the underlying connective tissue, in vacuoles within migrant cells, in vesicular compartments of the capillary endothelia, in capillary lumina, and in intravascular leucocytes. Tracer molecules were never observed to enter stacked Golgi cisternae. Since the cationic marker probably follows retrograde pathways of the protein secretion, the experimental data support the morphologically derived conclusions that postulate a major role for the IOE in transepithelial transport.

  2. Using the tracer-dilution discharge method to develop streamflow records for ice-affected streams in Colorado

    Science.gov (United States)

    Capesius, Joseph P.; Sullivan, Joseph R.; O'Neill, Gregory B.; Williams, Cory A.

    2005-01-01

    Accurate ice-affected streamflow records are difficult to obtain for several reasons, which makes the management of instream-flow water rights in the wintertime a challenging endeavor. This report documents a method to improve ice-affected streamflow records for two gaging stations in Colorado. In January and February 2002, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, conducted an experiment using a sodium chloride tracer to measure streamflow under ice cover by the tracer-dilution discharge method. The purpose of this study was to determine the feasibility of obtaining accurate ice-affected streamflow records by using a sodium chloride tracer that was injected into the stream. The tracer was injected at two gaging stations once per day for approximately 20 minutes for 25 days. Multiple-parameter water-quality sensors at the two gaging stations monitored background and peak chloride concentrations. These data were used to determine discharge at each site. A comparison of the current-meter streamflow record to the tracer-dilution streamflow record shows different levels of accuracy and precision of the tracer-dilution streamflow record at the two sites. At the lower elevation and warmer site, Brandon Ditch near Whitewater, the tracer-dilution method overestimated flow by an average of 14 percent, but this average is strongly biased by outliers. At the higher elevation and colder site, Keystone Gulch near Dillon, the tracer-dilution method experienced problems with the tracer solution partially freezing in the injection line. The partial freezing of the tracer contributed to the tracer-dilution method underestimating flow by 52 percent at Keystone Gulch. In addition, a tracer-pump-reliability test was conducted to test how accurately the tracer pumps can discharge the tracer solution in conditions similar to those used at the gaging stations. Although the pumps were reliable and consistent throughout the 25-day study period

  3. Mathematical basis for the measurement of absolute and fractional cardiac output with diffusible tracers by compartmental analysis methods

    International Nuclear Information System (INIS)

    Charkes, N.D.

    1984-01-01

    Using compartmental analysis methods, a mathematical basis is given for the measurement of absolute and fractional cardiac output with diffusible tracers. Cardiac output is shown to be the product of the blood volume and the sum of the rate constants of tracer egress from blood, modified by a factor reflecting transcapillary diffusibility, the transfer fraction. The return of tracer to the blood and distant (intracellular) events are shown to play no role in the solution. Fractional cardiac output is the ratio of the rate constant of tracer egress from blood to an organ, divided by the sum of the egress constants from blood. Predominantly extracellular ions such as sodium or bromide are best suited for this technique, although theoretically any diffusible tracer whose compartmental model can be solved may be used. It is shown that fractional cardiac output is independent of the transfer fraction, and therefore can be measured accurately by tracers which are not freely diffusible

  4. A dual tracer ratio method for comparative emission measurements in an experimental dairy housing

    Science.gov (United States)

    Mohn, Joachim; Zeyer, Kerstin; Keck, Margret; Keller, Markus; Zähner, Michael; Poteko, Jernej; Emmenegger, Lukas; Schrade, Sabine

    2018-04-01

    Agriculture, and in particular dairy farming, is an important source of ammonia (NH3) and non-carbon dioxide greenhouse gas (GHG) emissions. This calls for the development and quantification of effective mitigation strategies. Our study presents the implementation of a dual tracer ratio method in a novel experimental dairy housing with two identical, but spatially separated housing areas. Modular design and flexible floor elements allow the assessment of structural, process engineering and organisational abatement measures at practical scale. Thereby, the emission reduction potential of specific abatement measures can be quantified in relation to a reference system. Emissions in the naturally ventilated housing are determined by continuous dosing of two artificial tracers (sulphur hexafluoride SF6, trifluoromethylsulphur pentafluoride SF5CF3) and their real-time detection in the ppt range with an optimized GC-ECD method. The two tracers are dosed into different experimental sections, which enables the independent assessment of both housing areas. Mass flow emissions of NH3 and GHGs are quantified by areal dosing of tracer gases and multipoint sampling as well as real-time analysis of both tracer and target gases. Validation experiments demonstrate that the technique is suitable for both areal and point emission sources and achieves an uncertainty of less than 10% for the mass emissions of NH3, methane (CH4) and carbon dioxide (CO2), which is superior to other currently available methods. Comparative emission measurements in this experimental dairy housing will provide reliable, currently unavailable information on emissions for Swiss dairy farming and demonstrate the reduction potential of mitigation measures for NH3, GHGs and potentially other pollutants.

  5. Measuring serotonin synthesis: from conventional methods to PET tracers and their (pre)clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Anniek K.D.; Waarde, Aren van; Willemsen, Antoon T.M. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Bosker, Fokko J. [University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Luiten, Paul G.M. [University of Groningen, Center for Behavior and Neurosciences, Department of Molecular Neurobiology, Haren (Netherlands); Boer, Johan A. den [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, University Center of Psychiatry, Groningen (Netherlands); Kema, Ido P. [University of Groningen, University Medical Center Groningen, Department of Laboratory Medicine, Groningen (Netherlands); Dierckx, Rudi A.J.O. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

    2011-03-15

    The serotonergic system of the brain is complex, with an extensive innervation pattern covering all brain regions and endowed with at least 15 different receptors (each with their particular distribution patterns), specific reuptake mechanisms and synthetic processes. Many aspects of the functioning of the serotonergic system are still unclear, partially because of the difficulty of measuring physiological processes in the living brain. In this review we give an overview of the conventional methods of measuring serotonin synthesis and methods using positron emission tomography (PET) tracers, more specifically with respect to serotonergic function in affective disorders. Conventional methods are invasive and do not directly measure synthesis rates. Although they may give insight into turnover rates, a more direct measurement may be preferred. PET is a noninvasive technique which can trace metabolic processes, like serotonin synthesis. Tracers developed for this purpose are {alpha}-[{sup 11}C]methyltryptophan ([{sup 11}C]AMT) and 5-hydroxy-L-[{beta}-{sup 11}C]tryptophan ([{sup 11}C]5-HTP). Both tracers have advantages and disadvantages. [{sup 11}C]AMT can enter the kynurenine pathway under inflammatory conditions (and thus provide a false signal), but this tracer has been used in many studies leading to novel insights regarding antidepressant action. [{sup 11}C]5-HTP is difficult to produce, but trapping of this compound may better represent serotonin synthesis. AMT and 5-HTP kinetics are differently affected by tryptophan depletion and changes of mood. This may indicate that both tracers are associated with different enzymatic processes. In conclusion, PET with radiolabelled substrates for the serotonergic pathway is the only direct way to detect changes of serotonin synthesis in the living brain. (orig.)

  6. Measurements of industrial fugitive emissions by the FTIR Tracer Method (FTM)

    International Nuclear Information System (INIS)

    Mellqvist, J.; Arlander, B.; Galle, B.; Bergqvist, B.

    1996-01-01

    A new method called the FTIR Tracer Method (FTM), has been developed for measuring and quantifying fugitive (diffuse) emissions of hydrocarbons. The method has been evaluated in field experiments which were conducted in the vicinity of several petrochemical plants and an oil refinery during 1993-1995. The technique is based on concentration measurements with infrared remote sensing by Long Path Fourier Transform InfraRed (LPFTIR), combined with tracer releases. The field experiments show the FTM to be very useful for mass flux measurements of both alkanes and alkenes and that the measurements are consistent with the conventional SF 6 method. However, the technique needs to be further validated and a more thorough understanding of the measurement uncertainties have to be achieved

  7. TRACER: an ‘eye-opener’ to the patient experience across the transition of care in an internal medicine resident program

    Directory of Open Access Journals (Sweden)

    Lauren B. Meade

    2015-04-01

    Full Text Available Background: A safe patient transition requires a complex set of physician skills within the interprofessional practice. Objective: To evaluate a rotation which applies self-reflection and workplace learning in a TRAnsition of CarE Rotation (TRACER for internal medicine (IM residents. TRACER is a 2-week required IM resident rotation where trainees join a ward team as a quality officer and follow patients into postacute care. Methods: In 2010, residents participated in semistructured, one-on-one interviews as part of ongoing program evaluation. They were asked what they had learned on TRACER, the year prior, and how they used those skills in their practice. Using transcripts, the authors reviewed and coded each transcript to develop themes. Results: Five themes emerged from a qualitative, grounded theory analysis: seeing things from the other side, the ‘ah ha’ moment of fragmented care, team collaboration including understanding nursing scope of practice in different settings, patient understanding, and passing the learning on. TRACER gives residents a moment to breathe and open their eyes to the interprofessional practice setting and the patient's experience of care in transition. Conclusions: Residents learn about transitions of care through self-reflection. This learning is sustained over time and is valued enough to teach to their junior colleagues.

  8. The method of radioactive tracer for measuring the amount of inorganic nanoparticles in biological samples

    Science.gov (United States)

    Buzulukov, Yu; Antsiferova, A.; Demin, V. A.; Demin, V. F.; Kashkarov, P.

    2015-11-01

    The method to measure the mass of inorganic nanoparticles in biological (or any other samples) using nanoparticles labeled with radioactive tracers is developed and applied to practice. The tracers are produced in original nanoparticles by radioactive activation of some of their atomic nuclei. The method of radioactive tracers demonstrates a sensitivity, specificity and accuracy equal or better than popular methods of optical and mass spectrometry, or electron microscopy and has some specific advantages. The method can be used for study of absorption, distribution, metabolism and excretion in living organism, as well as in ecological and fundamental research. It was used in practice to study absorption, distribution, metabolism and excretion of nanoparticles of Ag, Au, Se, ZnO, TiO2 as well as to study transportation of silver nanoparticles through the barriers of blood-brain, placenta and milk gland of rats. Brief descriptions of data obtained in experiments with application of this method included in the article. The method was certified in Russian Federation standard system GOST-R and recommended by the Russian Federation regulation authority ROSPOTREBNADZOR for measuring of toxicokinetic and organotropy parameters of nanoparticles.

  9. An Efficient Method for Detection of Outliers in Tracer Curves Derived from Dynamic Contrast-Enhanced Imaging

    Directory of Open Access Journals (Sweden)

    Linning Ye

    2018-01-01

    Full Text Available Presence of outliers in tracer concentration-time curves derived from dynamic contrast-enhanced imaging can adversely affect the analysis of the tracer curves by model-fitting. A computationally efficient method for detecting outliers in tracer concentration-time curves is presented in this study. The proposed method is based on a piecewise linear model and implemented using a robust clustering algorithm. The method is noniterative and all the parameters are automatically estimated. To compare the proposed method with existing Gaussian model based and robust regression-based methods, simulation studies were performed by simulating tracer concentration-time curves using the generalized Tofts model and kinetic parameters derived from different tissue types. Results show that the proposed method and the robust regression-based method achieve better detection performance than the Gaussian model based method. Compared with the robust regression-based method, the proposed method can achieve similar detection performance with much faster computation speed.

  10. Recover Act. Verification of Geothermal Tracer Methods in Highly Constrained Field Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Matthew W. [California State University, Long Beach, CA (United States)

    2014-05-16

    The prediction of the geothermal system efficiency is strong linked to the character of the flow system that connects injector and producer wells. If water flow develops channels or “short circuiting” between injection and extraction wells thermal sweep is poor and much of the reservoir is left untapped. The purpose of this project was to understand how channelized flow develops in fracture geothermal reservoirs and how it can be measured in the field. We explored two methods of assessing channelization: hydraulic connectivity tests and tracer tests. These methods were tested at a field site using two verification methods: ground penetrating radar (GPR) images of saline tracer and heat transfer measurements using distributed temperature sensing (DTS). The field site for these studies was the Altona Flat Fractured Rock Research Site located in northeastern New York State. Altona Flat Rock is an experimental site considered a geologic analog for some geothermal reservoirs given its low matrix porosity. Because soil overburden is thin, it provided unique access to saturated bedrock fractures and the ability image using GPR which does not effectively penetrate most soils. Five boreholes were drilled in a “five spot” pattern covering 100 m2 and hydraulically isolated in a single bedding plane fracture. This simple system allowed a complete characterization of the fracture. Nine small diameter boreholes were drilled from the surface to just above the fracture to allow the measurement of heat transfer between the fracture and the rock matrix. The focus of the hydraulic investigation was periodic hydraulic testing. In such tests, rather than pumping or injection in a well at a constant rate, flow is varied to produce an oscillating pressure signal. This pressure signal is sensed in other wells and the attenuation and phase lag between the source and receptor is an indication of hydraulic connection. We found that these tests were much more effective than constant

  11. Quantification of methane and nitrous oxide emissions from various waste treatment facilities by tracer dilution method

    Science.gov (United States)

    Mønster, Jacob; Rella, Chris; Jacobson, Gloria; Kjeldsen, Peter; Scheutz, Charlotte

    2013-04-01

    Urban activities generate solid and liquid waste, and the handling and aftercare of the waste results in the emission of various compounds into the surrounding environment. Some of these compounds are emitted as gasses into the atmosphere, including methane and nitrous oxide. Methane and nitrous oxide are strong greenhouse gases and are considered to have 25 and 298 times the greenhouse gas potential of carbon dioxide on a hundred years term (Solomon et al. 2007). Global observations of both gasses have shown increasing concentrations that significantly contribute to the greenhouse gas effect. Methane and nitrous oxide are emitted from both natural and anthropogenic sources and inventories of source specific fugitive emissions from the anthropogenic sources of methane and nitrous oxide of are often estimated on the basis of modeling and mass balance. Though these methods are well-developed, actual measurements for quantification of the emissions is a very useful tool for verifying the modeling and mass balance as well as for validation initiatives done for lowering the emissions of methane and nitrous oxide. One approach to performing such measurements is the tracer dilution method (Galle et al. 2001, Scheutz et al. 2011), where the exact location of the source is located and a tracer gas is released at this source location at a known flow. The ratio of downwind concentrations of the tracer gas and the methane and nitrous oxide gives the emissions rates of the greenhouse gases. This tracer dilution method can be performed using both stationary and mobile measurements and in both cases, real-time measurements of both tracer and quantified gas are required, placing high demands on the analytical detection method. To perform the methane and nitrous oxide measurements, two robust instruments capable of real-time measurements were used, based on cavity ring-down spectroscopy and operating in the near-infrared spectral region. One instrument measured the methane and

  12. [Verification of ballast water exchange for international ships anchored in Xiamen Port by CDOM tracer].

    Science.gov (United States)

    Li, Chao; Zhang, Yan-po; Guo, Wei-dong; Zhu, Yue; Xu, Jing; Deng, Xun

    2010-09-01

    Fluorescence excitation-emission matrix (EEM) and absorption spectroscopy were applied to study the optical properties of 29 CDOM samples collected from different ballast tanks of nine international route vessels anchored in Xiamen Port between October 2007 and April 2008. The purpose was to examine the feasibility of these spectral properties as a tracer to verify if these vessels follow the mid-ocean ballast water exchange (BWE) regulation. Using parallel factor analysis, four fluorescent components were identified, including two humic-like components (C1: 245, 300/386 nm; C2: 250, 345/458 nm) and two protein-like components (C3: 220, 275/306 nm; C4: 235, 290/345 nm), of which C2 component was the suitable fluorescence verification indicator. The vertical distribution of all fluorescent components in ballast tank was nearly similar indicating that profile-mixing sampling was preferable. Combined use of C2 component, spectral slope ratio (SR) of absorption spectroscopy and salinity may provide reasonable verification if BWE carried out by these nine ships. The results suggested that the combined use of multiple parameters (fluorescence, absorption and salinity) would be much reliable to determine the origin of ballast water, and to provide the technical guarantee for fast examination of ballast water exchange in Chinese ports.

  13. Measurement of the odor impact of a waste deposit using the SF6-tracer method

    International Nuclear Information System (INIS)

    Roetzer, H.; Muehldorf, V.; Riesing, J.

    1994-12-01

    Landfill gas emitted from a waste deposit often causes odor nuisance in the vicinity. For a new sanitary landfill to be established in an area where also other sources of odor existed, very low limits for additional odor nuisance were given by local authorities. To verify that the odor concentrations were below these limit values, the odor contributions of different sources had to be distinguished. Olfactometric methods, using human observers to estimate the intensity of odors, were not applicable to this problem. For direct measurements by analytical methods concentrations of odorous substances were too small. Therefore a tracer method was applied to measure the odor impact of the sanitary landfill to its environment. The emitted landfill gas was labelled with the tracer gas SF 6 . The tracer gas was parted to even amounts and released through ten special nozzles equally distributed over the surface of the landfill. In the area around the landfill the concentration of the tracer gas was measured by collecting air samples and analysing them with a gas chromatograph with an electron capture detector. Fifteen air sampling units were used to collect eight consecutive air samples at each selected point. These measurements gave the relation between the emission of landfill gas and the resulting concentrations in ambient air. With these transmission coefficients the concentrations of odorous gases at the sampling points were evaluated, using the emission concentrations measured by analytical techniques at the landfiIl site. The resulting odor concentrations were compared with values of odor thresholds to establish the odor impact of the waste deposit on the environment. (author)

  14. Direct inversion of circulation and mixing from tracer measurements – Part 1: Method

    Directory of Open Access Journals (Sweden)

    T. von Clarmann

    2016-11-01

    Full Text Available From a series of zonal mean global stratospheric tracer measurements sampled in altitude vs. latitude, circulation and mixing patterns are inferred by the inverse solution of the continuity equation. As a first step, the continuity equation is written as a tendency equation, which is numerically integrated over time to predict a later atmospheric state, i.e., mixing ratio and air density. The integration is formally performed by the multiplication of the initially measured atmospheric state vector by a linear prediction operator. Further, the derivative of the predicted atmospheric state with respect to the wind vector components and mixing coefficients is used to find the most likely wind vector components and mixing coefficients which minimize the residual between the predicted atmospheric state and the later measurement of the atmospheric state. Unless multiple tracers are used, this inversion problem is under-determined, and dispersive behavior of the prediction further destabilizes the inversion. Both these problems are addressed by regularization. For this purpose, a first-order smoothness constraint has been chosen. The usefulness of this method is demonstrated by application to various tracer measurements recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. This method aims at a diagnosis of the Brewer–Dobson circulation without involving the concept of the mean age of stratospheric air, and related problems like the stratospheric tape recorder, or intrusions of mesospheric air into the stratosphere.

  15. The Tracer Gas Method of Determining the Charging Efficiency of Two-stroke-cycle Diesel Engines

    Science.gov (United States)

    Schweitzer, P H; Deluca, Frank, Jr

    1942-01-01

    A convenient method has been developed for determining the scavenging efficiency or the charging efficiency of two-stroke-cycle engines. The method consists of introducing a suitable tracer gas into the inlet air of the running engine and measuring chemically its concentration both in the inlet and exhaust gas. Monomethylamine CH(sub 3)NH(sub 2) was found suitable for the purpose as it burns almost completely during combustion, whereas the "short-circuited" portion does not burn at all and can be determined quantitatively in the exhaust. The method was tested both on four-stroke and on two-stroke engines and is considered accurate within 1 percent.

  16. A feature point identification method for positron emission particle tracking with multiple tracers

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, Cody, E-mail: cwiggin2@vols.utk.edu [University of Tennessee-Knoxville, Department of Physics and Astronomy, 1408 Circle Drive, Knoxville, TN 37996 (United States); Santos, Roque [University of Tennessee-Knoxville, Department of Nuclear Engineering (United States); Escuela Politécnica Nacional, Departamento de Ciencias Nucleares (Ecuador); Ruggles, Arthur [University of Tennessee-Knoxville, Department of Nuclear Engineering (United States)

    2017-01-21

    A novel detection algorithm for Positron Emission Particle Tracking (PEPT) with multiple tracers based on optical feature point identification (FPI) methods is presented. This new method, the FPI method, is compared to a previous multiple PEPT method via analyses of experimental and simulated data. The FPI method outperforms the older method in cases of large particle numbers and fine time resolution. Simulated data show the FPI method to be capable of identifying 100 particles at 0.5 mm average spatial error. Detection error is seen to vary with the inverse square root of the number of lines of response (LORs) used for detection and increases as particle separation decreases. - Highlights: • A new approach to positron emission particle tracking is presented. • Using optical feature point identification analogs, multiple particle tracking is achieved. • Method is compared to previous multiple particle method. • Accuracy and applicability of method is explored.

  17. 237 Np analytical method using 239 Np tracers and application to a contaminated nuclear disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Mathew S.; Morrison, Samuel S.; Clark, Sue B.; Olson, John E.; Watrous, Matthew G.

    2017-06-01

    Environmental 237Np analyses are challenged by low 237Np concentrations and lack of an available yield tracer; we report a rapid, inexpensive 237Np analytical approach employing the short lived 239Np (t1/2 = 2.3 days) as a chemical yield tracer followed by 237Np quantification using inductively coupled plasma-mass spectrometry. 239Np tracer is obtained via separation from a 243Am stock solution and standardized using gamma spectrometry immediately prior to sample processing. Rapid digestions using a commercial, 900 watt “Walmart” microwave and Parr microwave vessels result in 99.8 ± 0.1% digestion yields, while chromatographic separations enable Np/U separation factors on the order of 106 and total Np yields of 95 ± 4% (2σ). Application of this method to legacy soil samples surrounding a radioactive disposal facility (the Subsurface Disposal Area at Idaho National Laboratory) reveal the presence of low level 237Np contamination within 600 meters of this site, with maximum 237Np concentrations on the order of 103 times greater than nuclear weapons testing fallout levels.

  18. 237Np analytical method using 239Np tracers and application to a contaminated nuclear disposal facility.

    Science.gov (United States)

    Snow, Mathew S; Morrison, Samuel S; Clark, Sue B; Olson, John E; Watrous, Matthew G

    2017-06-01

    Environmental 237 Np analyses are challenged by low 237 Np concentrations and lack of an available yield tracer; we report a rapid, inexpensive 237 Np analytical approach employing the short lived 239 Np (t 1/2  = 2.3 days) as a chemical yield tracer followed by 237 Np quantification using inductively coupled plasma-mass spectrometry. 239 Np tracer is obtained via separation from a 243 Am stock solution and standardized using gamma spectrometry immediately prior to sample processing. Rapid digestions using a commercial, 900 W "Walmart" microwave and Parr microwave vessels result in 99.8 ± 0.1% digestion yields, while chromatographic separations enable Np/U separation factors on the order of 10 6 and total Np yields of 95 ± 4% (2σ). Application of this method to legacy soil samples surrounding a radioactive disposal facility (the Subsurface Disposal Area at Idaho National Laboratory) reveal the presence of low level 237 Np contamination within 600 m of this site, with maximum 237 Np concentrations on the order of 10 3 times greater than nuclear weapons testing fallout levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Standardization of low energy beta and beta-gamma complex emitters by the tracer and the efficiency extrapolation methods

    International Nuclear Information System (INIS)

    Sahagia, M.

    1978-01-01

    The absolute standardization of radioactive solutions of low energy beta emitters and beta-gamma emitters with a high probability of disintegration to the ground state is described; the tracer and the efficiency extrapolation methods were used. Both types of radionuclides were mathematically and physically treated in an unified manner. The theoretical relations between different beta spectra were calculated according to Williams' model and experimentally verified for: 35 S + 60 Co, 35 S + 95 Nb, 147 Pm + 60 Co, 14 C + 95 Nb and two beta branches of 99 Mo. The optimum range of beta efficiency variation was indicated. The basic supposition that all beta efficieny tend to unity in the same time was experimentally verified, using two 192 Ir beta branches. Four computer programs, written in the FORTRAN IV language, were elaborated, for the adequate processing of the experimental data. Good precision coefficients according to international standards were obtained in the absolute standardization of 35 S, 147 Pm, 99 Mo solutions. (author)

  20. Inverse modelling of atmospheric tracers: non-Gaussian methods and second-order sensitivity analysis

    Directory of Open Access Journals (Sweden)

    M. Bocquet

    2008-02-01

    Full Text Available For a start, recent techniques devoted to the reconstruction of sources of an atmospheric tracer at continental scale are introduced. A first method is based on the principle of maximum entropy on the mean and is briefly reviewed here. A second approach, which has not been applied in this field yet, is based on an exact Bayesian approach, through a maximum a posteriori estimator. The methods share common grounds, and both perform equally well in practice. When specific prior hypotheses on the sources are taken into account such as positivity, or boundedness, both methods lead to purposefully devised cost-functions. These cost-functions are not necessarily quadratic because the underlying assumptions are not Gaussian. As a consequence, several mathematical tools developed in data assimilation on the basis of quadratic cost-functions in order to establish a posteriori analysis, need to be extended to this non-Gaussian framework. Concomitantly, the second-order sensitivity analysis needs to be adapted, as well as the computations of the averaging kernels of the source and the errors obtained in the reconstruction. All of these developments are applied to a real case of tracer dispersion: the European Tracer Experiment [ETEX]. Comparisons are made between a least squares cost function (similar to the so-called 4D-Var approach and a cost-function which is not based on Gaussian hypotheses. Besides, the information content of the observations which is used in the reconstruction is computed and studied on the application case. A connection with the degrees of freedom for signal is also established. As a by-product of these methodological developments, conclusions are drawn on the information content of the ETEX dataset as seen from the inverse modelling point of view.

  1. Determination of optimum mixing time for raw materials with the tracer method in the glass industry

    Energy Technology Data Exchange (ETDEWEB)

    Gallyas, M; Gemesi, J; Kurinka, J

    1983-02-01

    The authors explain how the optimum mixing time for the raw materials for glass manufacture can be determined with the aid of the radioactive tracer method. Basing themselves on measurements, they indicate the change in the degree of mixing of the individual components (soda (Na-24), sodium sulphate, coke (La-140) and bone meal (P-32) as a function of mixing time. The optimum degree of mixing and mixing time for dry and for wet mixing are determined. Finally, data for determining the permissible storage time of the mixture are given.

  2. Field measurement of mixing degree in coal mixer by later activable tracer method

    International Nuclear Information System (INIS)

    Yokooji, Makoto; Uemura, Katsumi; Adachi, Syoichi

    1975-01-01

    Mixing effectiveness in a rotary drum mixer for coke production was examined. Though the method to use the dispersion of characteristic values such as ash content or volatile components is common for measuring the mixing effectiveness, here the later activable tracer method with radioisotopes was employed, because the former method includes the dispersion of the characteristic values for raw materials themselves, and is poor in detectability. In a preliminary test, the expression for mixing degree was determined, and the tracer nuclide was selected. Coal mixture was irradiated in the TRIGA II reactor of St. Paul University for 4 hours at 100 kW. then further preliminary test was performed for La and Mn which were selected among the typical usable elements listed up by reviewing their γ-spectra. Finally, Mn was adopted by comparing both elements regarding their time required for activation analysis and economy. Manganese concentration originally contained in the coal mixture was 38 ppm. Mixing degree after passing through the coal mixer was 99.8%. The results of the regular test are shown in a table, and indicate that the mixer fully attained its aim. (Wakatsuki, Y.)

  3. Greenhouse gas emission quantification from wastewater treatment plants, using a tracer gas dispersion method

    DEFF Research Database (Denmark)

    Delre, Antonio; Mønster, Jacob; Scheutz, Charlotte

    2017-01-01

    Plant-integrated methane (CH4) and nitrous oxide (N2O) emission quantifications were performed at five Scandinavian wastewater treatment plants, using a ground-based remote sensing approach that combines a controlled release of tracer gas from the plant with downwind concentration measurements. CH4...... emission factors were between 1 and 21% of CH4 production, and between 0.2 and 3.2% of COD influent. The main CH4 emitting sources at the five plants were sludge treatment and energy production units. The lowest CH4 emission factors were obtained at plants with enclosed sludge treatment and storage units...... in international guidelines. This study showed that measured CH4 and N2O emission rates from wastewater treatment plants were plant-specific and that emission rates estimated using models in current guidelines, mainly meant for reporting emissions on the country scale, were unsuitable for Scandinavian plant...

  4. Using tracer methods and experimental design approach for examination of hydrodynamic conditions in membrane separation modules

    Energy Technology Data Exchange (ETDEWEB)

    Miskiewicz, Agnieszka, E-mail: a.miskiewicz@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Zakrzewska-Trznadel, Grazyna; Dobrowolski, Andrzej; Jaworska-Sobczak, Agnieszka [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland)

    2012-05-15

    The possibility of application of fluorescein and radioactive 99mTc as tracers for determination of residence time distribution of liquid phase and for diagnosing hydrodynamic conditions in apparatuses for membrane separation was studied. Two different ultrafiltration systems with diverse arrangement of liquid flow: the apparatus with helical flow generated by the movable element (inner cylinder) and the tubular module with cross flow filtration, were tested by the RTD technique. The tracer studies were supplemented with modelling. The optimal conditions enabling to handle the plug flow-like structure in the helical apparatus were determined. The minimum of dimensionless variance (vard) was obtained at P=0.765 bar, Q{sub R}=121.88 l/h and {Omega}=2887.5 rpm. In spite of higher linear velocities attained in the tubular cross-flow module, the flow structure in the helical apparatus was more similar to the ideal plug flow pattern that was demonstrated by higher Peclet numbers and lower values of the dimensionless variance. Application of movable part and Couette-Taylor flow in the membrane apparatus may balance the advantages coming from high flow rates applied in cross-flow filtration systems minimising formation of the deposit on the membrane surface and reducing membrane fouling. - Highlights: Black-Right-Pointing-Pointer Application of RTD method with modelling for testing the membrane modules. Black-Right-Pointing-Pointer The use of generator isotope, as convenient tracer for the membrane modules studies. Black-Right-Pointing-Pointer Application of RSM with experimental design for testing interactions between parameters. Black-Right-Pointing-Pointer Assessment of the hydrodynamic conditions in two arrangements of the membrane modules. Black-Right-Pointing-Pointer Demonstration of the advantage of dynamic filtration over the cross-flow arrangement.

  5. Quantification of methane emissions from 15 Danish landfills using the mobile tracer dispersion method

    Energy Technology Data Exchange (ETDEWEB)

    Mønster, Jacob [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark); Samuelsson, Jerker, E-mail: jerker.samuelsson@fluxsense.se [Chalmers University of Technology/FluxSense AB, SE-41296 Göteborg (Sweden); Kjeldsen, Peter [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark); Scheutz, Charlotte, E-mail: chas@env.dtu.dk [Department of Environmental Engineering, Technical University of Denmark, Miljøvej – Building 113, DK-2800 Lyngby (Denmark)

    2015-01-15

    Highlights: • Quantification of whole landfill site methane emission at 15 landfills. • Multiple on-site source identification and quantification. • Quantified methane emission from shredder waste and composting. • Large difference between measured and reported methane emissions. - Abstract: Whole-site methane emissions from 15 Danish landfills were assessed using a mobile tracer dispersion method with either Fourier transform infrared spectroscopy (FTIR), using nitrous oxide as a tracer gas, or cavity ring-down spectrometry (CRDS), using acetylene as a tracer gas. The landfills were chosen to represent the different stages of the lifetime of a landfill, including open, active, and closed covered landfills, as well as those with and without gas extraction for utilisation or flaring. Measurements also included landfills with biocover for oxidizing any fugitive methane. Methane emission rates ranged from 2.6 to 60.8 kg h{sup −1}, corresponding to 0.7–13.2 g m{sup −2} d{sup −1}, with the largest emission rates per area coming from landfills with malfunctioning gas extraction systems installed, and the smallest emission rates from landfills closed decades ago and landfills with an engineered biocover installed. Landfills with gas collection and recovery systems had a recovery efficiency of 41–81%. Landfills where shredder waste was deposited showed significant methane emissions, with the largest emission from newly deposited shredder waste. The average methane emission from the landfills was 154 tons y{sup −1}. This average was obtained from a few measurement campaigns conducted at each of the 15 landfills and extrapolating to annual emissions requires more measurements. Assuming that these landfills are representative of the average Danish landfill, the total emission from Danish landfills were calculated at 20,600 tons y{sup −1}, which is significantly lower than the 33,300 tons y{sup −1} estimated for the national greenhouse gas inventory for

  6. ASSESSMENT METHODS OF INTERNAL AUDIT

    Directory of Open Access Journals (Sweden)

    Elena RUSE

    2015-12-01

    Full Text Available Internal audit services are more and more needed within economic entities, because on one hand they are directly subordinated to the general manager, on the other hand there is an increase in credit to its recommendations, estimating that internal audit is more than just a simple compliance check based on an established referral system. Our research focuses on evaluating the impact of theory and practice in the application of internal audit process. The added value brought by internal audit function to the economic entity it is pretty difficult to establish and requires effective ways and criteria of measured. In this regard, we will try to present ways to analyze internal audit’s activity by reference to some performance indicators or other specific methods. We used as research techniques: literature review, applied research and constructive research.

  7. Tracer methods to quantify nutrient uptake from plough layer, sub-soil and fertilizer: implications on sustainable nutrient management

    Energy Technology Data Exchange (ETDEWEB)

    Haak, E [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Radioecology

    1996-07-01

    Two soils injection methods are presented. The first method consists of homogeneously labelling the whole plough layer with carrier free tracers. this is done in two treatments, (1) a reference treatment without connection with the sub-soil and (2) an experimental treatment where the sub-soil is freely accessible for root penetration. The second method, which is now under development, consists of using isotope labelled fertilizers instead of carrier free tracers. By application of the A-value concept it is possible to quantify (by the first method) the plant uptake of nutrients from plough layer and sub-soil, and from the second method, the uptake of nutrients from the applied fertilizer. A fertilizer strategy for phosphorus is discussed based on data obtained from tracer experiment in the field, and soil survey of specific field sites. (author). 7 refs, 2 figs, 1 tab.

  8. Tracer methods to quantify nutrient uptake from plough layer, sub-soil and fertilizer: implications on sustainable nutrient management

    International Nuclear Information System (INIS)

    Haak, E.

    1996-01-01

    Two soils injection methods are presented. The first method consists of homogeneously labelling the whole plough layer with carrier free tracers. this is done in two treatments, (1) a reference treatment without connection with the sub-soil and (2) an experimental treatment where the sub-soil is freely accessible for root penetration. The second method, which is now under development, consists of using isotope labelled fertilizers instead of carrier free tracers. By application of the A-value concept it is possible to quantify (by the first method) the plant uptake of nutrients from plough layer and sub-soil, and from the second method, the uptake of nutrients from the applied fertilizer. A fertilizer strategy for phosphorus is discussed based on data obtained from tracer experiment in the field, and soil survey of specific field sites. (author). 7 refs, 2 figs, 1 tab

  9. A new method for measuring aerosol nebulizers output using radioactive tracers

    International Nuclear Information System (INIS)

    Gatnash, A.A.; Connolly, C.K.; Chandler, S.T.

    1998-01-01

    Reproducibility and comparability of bronchial challenge tests depends critically on accurate assessment of nebulizers output. Evaporation during nebulization means that simple weighing is inaccurate, overestimating the delivered dose of active ingredient. We wanted to quantify this effect in the context of intermittent nebulization, using a dosimeter as used in bronchial provocation tests. Output of three types of nebulizers, from the MEFAR dosimeter, was measured by radioactive tracer, using a standard solution of technetium-99m-pertechnetate (1.5 kBq x mL -1 ) in 4 mL of normal saline. The aerosol was impacted by suction onto a micro filter, and the radioactivity measured. Nebulizers were weighed before and after nebulization. Ratio of nebulized volume calculated from the radioactivity on the filter, to the total volume loss by weight, was expressed as nebulized ratio. The effect on output of two concentrations of methacholine, two tracers of different weights, and change in temperature, were assessed. Nebulized ratio varied between 44.1-71.6%. Results were more consistent within the same type of nebulizer than between different makes. Neither changes in molar concentration nor molecular weight affected nebulizer output or nebulized ratio. Mean nebulized ratio was 58.5%, showing that calibration by weighing, overestimates the delivered dose by a factor of approximately two. Measuring radioactivity eluted from a micro filter, onto which nebulized output had been impacted proved to be a satisfactory method of calibration. (au)

  10. Preconcentration method using an activatable yield tracer for neutron activation analysis

    International Nuclear Information System (INIS)

    Tsukada, Masamichi; Yamamoto, Daijiro; Endo, Kazutoyo; Nakahara, Hiromichi

    1991-01-01

    Previously, the use of an enriched stable isotope as an activatable yield tracer in preconcentration steps has been tested by use of commercially available enriched 116 Cd and 156 Dy for biological standard reference materials. In the present work, this method has been further applied to the determination of lanthanoid contents in various kinds of samples: one coal fly-ash, three Japanese standard rocks, and eight standard soils. Samples were decomposed by alkali fusion in the preconcentration step. Thirteen elements were determined for coal fly-ash and soil samples, and 14 elements for rocks. The data obtained for coal fly-ash and standard rocks are compared with the data reported in literature. The data for soil samples have been newly determined in the present work. The ordinary instrumental neutron activation analysis and radiochemical neutron activation analysis were also performed to confirm the accuracy and usefulness of the present method. (author) 10 refs.; 4 tabs

  11. A refinement of the potassium tracer method for residential wood smoke

    Science.gov (United States)

    Calloway, C. P.; Li, S.; Buchanan, J. W.; Stevens, R. K.

    Potassium has been used as a tracer for the mass of fine particles emitted to the air from residential wood burning stoves and fireplaces. The technique involves measurement by x-ray fluorescence of the total K collected on fine particle filters. Since wind blown soil particles also contain K, a correction for this contribution is made based upon soil analysis or an assumed K/Fe ratio in local soil. K in excess of this ratio is considered to be from wood smoke. The purpose of this study is to demonstrate an alternative method for determining wood smoke K. The underlying assumption is that wood smoke K is water soluble but that K in crustal particles is in a mineralized form and only slightly water soluble. Results from analyses of particle samples indicate the two methods yield essentially the same amount of wood smoke K.

  12. Measurement of protein digestibility in humans by a dual-tracer method.

    Science.gov (United States)

    Devi, Sarita; Varkey, Aneesia; Sheshshayee, M S; Preston, Thomas; Kurpad, Anura V

    2018-06-01

    Recent evaluations of the risk of dietary protein deficiency have indicated that protein digestibility may be a key limiting factor in the provision of indispensable amino acids (IAAs), particularly for vulnerable populations living in challenging environments where intestinal dysfunction may exist. Since the digestion of protein occurs only in the small intestine, and the metabolic activity of colonic bacteria confounds measurements at the fecal level, there is a need to develop noninvasive protein digestibility measurements at the ileal level. We used a dual-tracer method with stable isotopes to characterize the digestibility of uniformly labeled [13C]-spirulina protein as a standard protein, in comparison to a mixture of 2H-labeled crystalline amino acids, and then demonstrated the use of this standard protein to measure the digestibility of selected legumes (chick pea and mung bean) through the use of proteins that were intrinsically labeled with 2H. The digestibility of uniformly labeled [13C]-spirulina was first measured in 6 healthy volunteers (3 males and 3 females) by feeding it along with a standard mixture of 2H-labeled amino acids, in a dual-tracer, plateau-fed test meal approach. Next, intrinsically labeled legume protein digestibility was studied with a similar dual-tracer approach, with uniformly labeled [13C]-spirulina as the standard, when processed differently before consumption. The average digestibility of IAA in spirulina protein was 85.2%. The average IAA digestibility of intrinsically 2H-labeled chick pea and mung bean protein was 56.6% and 57.7%, respectively. Dehulling of mung bean before ingestion increased the average IAA digestibility by 9.9% in comparison to whole mung bean digestibility. An innovative, minimally invasive "dual-stable-isotope" method was developed to measure protein digestibility, in which the ingestion of an intrinsically 2H-labeled test protein along with a 13C-labeled standard protein of known digestibility allows

  13. Tracer diffusion in an ordered alloy: application of the path probability and Monte Carlo methods

    International Nuclear Information System (INIS)

    Sato, Hiroshi; Akbar, S.A.; Murch, G.E.

    1984-01-01

    Tracer diffusion technique has been extensively utilized to investigate diffusion phenomena and has contributed a great deal to the understanding of the phenomena. However, except for self diffusion and impurity diffusion, the meaning of tracer diffusion is not yet satisfactorily understood. Here we try to extend the understanding to concentrated alloys. Our major interest here is directed towards understanding the physical factors which control diffusion through the comparison of results obtained by the Path Probability Method (PPM) and those by the Monte Carlo simulation method (MCSM). Both the PPM and the MCSM are basically in the same category of statistical mechanical approaches applicable to random processes. The advantage of the Path Probability method in dealing with phenomena which occur in crystalline systems has been well established. However, the approximations which are inevitably introduced to make the analytical treatment tractable, although their meaning may be well-established in equilibrium statistical mechanics, sometimes introduce unwarranted consequences the origin of which is often hard to trace. On the other hand, the MCSM which can be carried out in a parallel fashion to the PPM provides, with care, numerically exact results. Thus a side-by-side comparison can give insight into the effect of approximations in the PPM. It was found that in the pair approximation of the CVM, the distribution in the completely random state is regarded as homogeneous (without fluctuations), and hence, the fluctuation in distribution is not well represented in the PPM. These examples thus show clearly how the comparison of analytical results with carefully carried out calculations by the MCSM guides the progress of theoretical treatments and gives insights into the mechanism of diffusion

  14. [Drainage characteristic of the brain interstitial fluid detected by using fluorescence and magnetic tracer method].

    Science.gov (United States)

    Zhao, Y; Li, Y Q; Li, H Y; Li, Y L; Liu, L X; Yuan, L; Zhang, S J; Han, H B

    2017-04-18

    Compare the results of molecular diffusion and mass flow in the interstitial space(ISS) displayed by using optical and magnetic probes and study partitioned drainage of the brain interstitial fluid (ISF). In the study, 36 male SD rats were randomly divided into fluorescent inspection group (18), magnetic tracer group (18). Then they were divided equally into caudate nucleus (Cn), thalamus (T) and substantia nigra (Sn) subgroup, 6 rats in each subgroup. Referencing the brain stereotaxic atlas, the coronal globus pallidus as center level, Cn, T or Sn were acted as puncture positioning target. A 10 μL microsyringe was stereotaxically positioned and the lucifer yellow (LY) solution of 2 μL 10 mmol/L was infused into centric position. The coronary slices undergo cardiac perfusion and fix respectively in time point Cn 3 h, T 2 h and Sn 1 h. The rat brain was placed in rat stainless steel brain matrices and cut backward along visual intersection. The injection point of coronal slice as the center level, take 3 slices in front of the center level and 2 slices behind of it. 1 mm for each slice and 6 slices in total. Then slices were detected by laser scanning confocal microscope (LSCM). Simultaneous, in the same coordinate brain regions of another three groups, a gadolinium-diethylene triamine pentaacetic acidm (Gd-DTPA) solution of 2 μL 10 mmol/L was infused into different injection and detected by MRI tracer-based method. Then the Radiant can be used to measure distribution area of Gd-DTPA. LY and Gd-DTPA have different distribution regions in Cn, T and Sn. After LY and Gd-DTPA were introduced into the Cn subgroup 3 h, compare the 1 to 6 levels distribution area of LY and Gd-DTPA as follows: (10.95±4.27) mm 2 vs. (8.33±2.25) mm 2 , (18.16±4.74) mm 2 vs. (16.42±2.88) mm 2 , (24.57±3.65) mm 2 vs. (20.75±2.29) mm 2 , (34.81±3.32) mm 2 vs. (28.88±1.51) mm 2 , (30.53±3.12) mm 2 vs. (20.92±2.75) mm 2 , (12.15±4.92) mm 2 vs. (10.00±1.89) mm 2 . The statistical

  15. Evaluation of Oceanic Transport Statistics By Use of Transient Tracers and Bayesian Methods

    Science.gov (United States)

    Trossman, D. S.; Thompson, L.; Mecking, S.; Bryan, F.; Peacock, S.

    2013-12-01

    Key variables that quantify the time scales over which atmospheric signals penetrate into the oceanic interior and their uncertainties are computed using Bayesian methods and transient tracers from both models and observations. First, the mean residence times, subduction rates, and formation rates of Subtropical Mode Water (STMW) and Subpolar Mode Water (SPMW) in the North Atlantic and Subantarctic Mode Water (SAMW) in the Southern Ocean are estimated by combining a model and observations of chlorofluorocarbon-11 (CFC-11) via Bayesian Model Averaging (BMA), statistical technique that weights model estimates according to how close they agree with observations. Second, a Bayesian method is presented to find two oceanic transport parameters associated with the age distribution of ocean waters, the transit-time distribution (TTD), by combining an eddying global ocean model's estimate of the TTD with hydrographic observations of CFC-11, temperature, and salinity. Uncertainties associated with objectively mapping irregularly spaced bottle data are quantified by making use of a thin-plate spline and then propagated via the two Bayesian techniques. It is found that the subduction of STMW, SPMW, and SAMW is mostly an advective process, but up to about one-third of STMW subduction likely owes to non-advective processes. Also, while the formation of STMW is mostly due to subduction, the formation of SPMW is mostly due to other processes. About half of the formation of SAMW is due to subduction and half is due to other processes. A combination of air-sea flux, acting on relatively short time scales, and turbulent mixing, acting on a wide range of time scales, is likely the dominant SPMW erosion mechanism. Air-sea flux is likely responsible for most STMW erosion, and turbulent mixing is likely responsible for most SAMW erosion. Two oceanic transport parameters, the mean age of a water parcel and the half-variance associated with the TTD, estimated using the model's tracers as

  16. Elucidation of hydrodesulfurization mechanism using 35S radioisotope pulse tracer methods

    International Nuclear Information System (INIS)

    Kabe, Toshiaki; Qian, Weihua; Ishihara, Atsushi

    1997-01-01

    Molybdenum-based catalysts as hydrodesulfurization (HDS) catalysts are among the most important industrial catalysts. One of the new approaches characterizing the structure of such catalysts and the behavior of sulfur over the 'working' catalyst is a 35S radioisotope pulse tracer method (RPTM). By tracing the behavior of sulfur in the HDS reaction and sulfur exchange reaction over the sulfided Mo/Al 2 O 3 and Co-Mo/Al 2 O 3 catalysts under practical reaction conditions, it becomes possible for us to observe the catalytic behavior of the catalyst in situ. The formation process of active sites, the important role that H 2 S plays in this process, and the promotion by cobalt for Mo/Al 2 O 3 catalyst have become better understood

  17. Quantification of Nitrous Oxide from Fugitive Emissions by Tracer Dilution Method using a Mobile Real-time Nitrous Oxide Analyzer

    Science.gov (United States)

    Mønster, J.; Rella, C.; Jacobson, G. A.; He, Y.; Hoffnagle, J.; Scheutz, C.

    2012-12-01

    Nitrous oxide is a powerful greenhouse gas considered 298 times stronger than carbon dioxide on a hundred years term (Solomon et al. 2007). The increasing global concentration is of great concern and is receiving increasing attention in various scientific and industrial fields. Nitrous oxide is emitted from both natural and anthropogenic sources. Inventories of source specific fugitive nitrous oxide emissions are often estimated on the basis of modeling and mass balance. While these methods are well-developed, actual measurements for quantification of the emissions can be a useful tool for verifying the existing estimation methods as well as providing validation for initiatives targeted at lowering unwanted nitrous oxide emissions. One approach to performing such measurements is the tracer dilution method (Galle et al. 2001), in which a tracer gas is released at the source location at a known flow. The ratio of downwind concentrations of both the tracer gas and nitrous oxide gives the ratios of the emissions rates. This tracer dilution method can be done with both stationary and mobile measurements; in either case, real-time measurements of both tracer and analyte gas is required, which places high demands on the analytical detection method. To perform the nitrous oxide measurements, a novel, robust instrument capable of real-time nitrous oxide measurements has been developed, based on cavity ring-down spectroscopy and operating in the near-infrared spectral region. We present the results of the laboratory and field tests of this instrument in both California and Denmark. Furthermore, results are presented from measurements using the mobile plume method with a tracer gas (acetylene) to quantify the nitrous oxide and methane emissions from known sources such as waste water treatment plants and composting facilities. Nitrous oxide (blue) and methane (yellow) plumes downwind from a waste water treatment facility.

  18. An evaluation of an improved method for computing histograms in dynamic tracer studies using positron-emission tomography

    International Nuclear Information System (INIS)

    Ollinger, J.M.; Snyder, D.L.

    1986-01-01

    A method for computing approximate minimum-mean-square-error estimates of histograms from list-mode data for use in dynamic tracer studies is evaluated. Parameters estimated from these histograms are significantly more accurate than those estimated from histograms computed by a commonly used method

  19. A method to investigate inter-aquifer leakage using hydraulics and multiple environmental tracers

    Science.gov (United States)

    Priestley, Stacey; Love, Andrew; Wohling, Daniel; Post, Vincent; Shand, Paul; Kipfer, Rolf; Tyroller, Lina

    2016-04-01

    Informed aquifer management decisions regarding sustainable yields or potential exploitation require an understanding of the groundwater system (Alley et al. 2002, Cherry and Parker 2004). Recently, the increase in coal seam gas (CSG) or shale gas production has highlighted the need for a better understanding of inter-aquifer leakage and contaminant migration. In most groundwater systems, the quantity or location of inter-aquifer leakage is unknown. Not taking into account leakage rates in the analysis of large scale flow systems can also lead to significant errors in the estimates of groundwater flow rates in aquifers (Love et al. 1993, Toth 2009). There is an urgent need for robust methods to investigate inter-aquifer leakage at a regional scale. This study builds on previous groundwater flow and inter-aquifer leakage studies to provide a methodology to investigate inter-aquifer leakage in a regional sedimentary basin using hydraulics and a multi-tracer approach. The methodology incorporates geological, hydrogeological and hydrochemical information in the basin to determine the likelihood and location of inter-aquifer leakage. Of particular benefit is the analysis of hydraulic heads and environmental tracers at nested piezometers, or where these are unavailable bore couplets comprising bores above and below the aquitard of interest within a localised geographical area. The proposed methodology has been successful in investigating inter-aquifer leakage in the Arckaringa Basin, South Australia. The suite of environmental tracers and isotopes used to analyse inter-aquifer leakage included the stable isotopes of water, radiocarbon, chloride-36, 87Sr/86Sr and helium isotopes. There is evidence for inter-aquifer leakage in the centre of the basin ~40 km along the regional flow path. This inter-aquifer leakage has been identified by a slight draw-down in the upper aquifer during pumping in the lower aquifer, overlap in Sr isotopes, δ2H, δ18O and chloride

  20. Evaluation of the transport matrix method for simulation of ocean biogeochemical tracers

    Science.gov (United States)

    Kvale, Karin F.; Khatiwala, Samar; Dietze, Heiner; Kriest, Iris; Oschlies, Andreas

    2017-06-01

    Conventional integration of Earth system and ocean models can accrue considerable computational expenses, particularly for marine biogeochemical applications. Offline numerical schemes in which only the biogeochemical tracers are time stepped and transported using a pre-computed circulation field can substantially reduce the burden and are thus an attractive alternative. One such scheme is the transport matrix method (TMM), which represents tracer transport as a sequence of sparse matrix-vector products that can be performed efficiently on distributed-memory computers. While the TMM has been used for a variety of geochemical and biogeochemical studies, to date the resulting solutions have not been comprehensively assessed against their online counterparts. Here, we present a detailed comparison of the two. It is based on simulations of the state-of-the-art biogeochemical sub-model embedded within the widely used coarse-resolution University of Victoria Earth System Climate Model (UVic ESCM). The default, non-linear advection scheme was first replaced with a linear, third-order upwind-biased advection scheme to satisfy the linearity requirement of the TMM. Transport matrices were extracted from an equilibrium run of the physical model and subsequently used to integrate the biogeochemical model offline to equilibrium. The identical biogeochemical model was also run online. Our simulations show that offline integration introduces some bias to biogeochemical quantities through the omission of the polar filtering used in UVic ESCM and in the offline application of time-dependent forcing fields, with high latitudes showing the largest differences with respect to the online model. Differences in other regions and in the seasonality of nutrients and phytoplankton distributions are found to be relatively minor, giving confidence that the TMM is a reliable tool for offline integration of complex biogeochemical models. Moreover, while UVic ESCM is a serial code, the TMM can

  1. Tumoral tracers

    International Nuclear Information System (INIS)

    Camargo, E.E.

    1979-01-01

    Direct tumor tracers are subdivided in the following categories:metabolite tracers, antitumoral tracers, radioactive proteins and cations. Use of 67 Ga-citrate as a clinically important tumoral tracer is emphasized and gallium-67 whole-body scintigraphy is discussed in detail. (M.A.) [pt

  2. Study of particle movement in conical fluidized beds using the tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Penkalla, H. J.; Gyarmati, E.; Nickel, H.

    1976-01-15

    In the work reported here, a method is described which enables the path and speed of the particles during fluidization to be measured using a tracer particle technique. Using statistical methods, it is then possible to determine the path-time diagram, the rate of circulation of the particles, the transport capacity, the extent of mixing and the relative residence time of the particles in a given zone of the bed. Measurements were made at room temperature in a 3'' model fluidized bed as a first step in evaluating the feasibility of the test method. Criteria for the type of coating, the growth rate of the coatings and the coating potential of the coating as were correlated with the relative dwell time of the particles and the dwell-time spectrum of the coating gases in a given part of the bed. It was therefore necessary to know the streaming behavior of the fluidizing gas, and so such an analysis was first carried out.

  3. Enhanced oil recovery methods studied by gamma tracer scanning at simulated reservoir conditions

    International Nuclear Information System (INIS)

    Eriksen, D.O.; Haugen, O.B.; Bjornstad, T.

    2009-01-01

    During recovery (production) of hydrocarbons pressure is maintained by injecting prepared sea water and recycled gas (lean gas) into dedicated injection wells. In one well at the Snorre field in the North Sea the injected gas was recycled too fast to enable support of pressure and squeezing of oil. To plug this high-permeable area the operator wanted to inject foam as a test of its possibilities to decrease gas permeability. As part of the project laboratory tests were included. In these tests we could for the first time map the foam inside the sandstone sample at simulated reservoir conditions. The tracers used were 22 Na + for the γ-scanning of the aqueous brine, tritiated water for permeability measurements, and 35 S-labeled organic sulfonic acid of the same compound as the surfactant. This method resulted in a 'negative' mapping of the foam, i.e. measurements of the absence or exclusion of the aqueous phase by the foam. This method was new and showed that radiotracer-based γ-scanning could give much more accurate measurements of the position of the foam than the standard method using measurements of pressure drops over parts of the core. (author)

  4. Measuring methane emissions from a UK landfill using the tracer dispersion method and the influence of operational and environmental factors

    DEFF Research Database (Denmark)

    Rees-White, T.; Mønster, Jacob; Beaven, R. P.

    2018-01-01

    The methane emissions from a landfill in south-east, UK were successfully quantified during a six-day measurement campaign using the tracer dispersion method. The fair weather conditions made it necessary to perform measurements in the late afternoon and in the evening when the lower solar flux...

  5. Quantitative assessment of metabolic bone disease in rat models by dual tracer method

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Fumishige; Seto, Hikaru

    1989-05-01

    The usefulness of radionuclide techniques for early differential diagnosis of metabolic bone disease has been controversial. We tried to develop a new method to distinguish alterations in bone metabolism prior to radiologic changes, measuring 24-hr whole-body retention (WBR) and femoral uptake of two radiopharmaceuticals (/sup 47/Ca-chloride, /sup 99m/Tc-MDT). Control normal (C), osteoporosis (P), osteomalacia (M) and steroid-induced osteoporosis (S) were produced in 60 eight-week old Wistar male rats by means of dietary manipulation and steroid administration. Fine detail radiographs of the femurs and bone specimens were obtained over six weeks at two week intervals. Good correlation between WBR and femoral uptake of /sup 47/Ca was noted (r=0.86, p<0.01). WBR ratios of /sup 47/Ca were significantly higher in the M and S groups and were lower in the P group when compared to the C group throughout the study. WBR ratios of /sup 99m/Tc-MDP were significantly higher in the M group and were lower in the S group from the 2nd week. Fine detail radiographs analyzed by microdensitometry revealed significant osteopenia in the S, M and P groups from the 4th week. The dual tracer method was found to distinguish alterations in bone metabolism in the groups examined prior to detectable radiologic changes. (author).

  6. Optimizing the mercury mass measurement in industrial electrolytic cells by the radio-tracer method at ININ

    International Nuclear Information System (INIS)

    Valle R, J.; Angeles C, A.

    2014-10-01

    One method used in the production of chlorine and sodium is the use of electrolytic cells for the separation of chlorine and sodium from the brine; the industries apply very intense electromagnetic fields in this process. The electrolytic cells use mercury as electrode. In a chlorine production plant inventories are determined by total amount of mercury in the plant annually, since mercury losses are large and a very important parameter is to control the mass of mercury for it is necessary to measure with great precision the losses made. There are several methods to determine the mass of mercury ranging from take samples and weigh, but this involves continuous interruption of the process creating downtimes which in turn represent economic losses giving a result delimiting productivity for the industrial sector. An alternative and attractive method is to use a radioactive tracer whose principle has a similar behavior to study objective. The inert mercury has to be neutron activated in a nuclear reactor to having the characteristics of a tracer; the result makes one of the isotopes of mercury. The tracer is transported taking into account the recommendations of the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexico), then it is injected into the electrolytic cells mixing with the mercury in the system. By a relative radioactivity measurement and one sample by gamma spectrometry per interest cell, the mass of mercury without stopping the process is obtained. For optimal use of radio-tracer method must be taken into account as important features: irradiation time of mercury, counting conditions, vial geometry, sample volume, sample cells, mixing time and half-life of the tracer. (Author)

  7. An independent method for input accountability in reprocessing plants : magnesium tracer technique for the accountability of plutonium (MAGTRAP)

    International Nuclear Information System (INIS)

    Mathews, C.K.; Jain, H.C.; Chitambar, S.A.; Kavimandan, V.D.; Aggarwal, S.K.

    1975-01-01

    A new technique 'MAGTRAP' for the measurement of the total plutonium in an accountability tank is described which does not require knowledge of either the total volume of solution in the tank or the size of the sample aliquot. The method depends on the addition of natural magnesium as a tracer and the subsequent isotope dilution of an aliquot using a spike with known 26 Mg/ 242 Pu ratio. Using only the isotopic ratios of 26 Mg/ 24 Mg and 239 Pu/ 242 Pu in the mixture, the quantity of the plutonium in the accountability tank can be calculated. In order to correct for magnesium blank, an additional measurement is required before tracer addition. The magnesium tracer technique can also be used to check the volume (or weight) calibration of the tank. Several experiments were carried out in the input accountability tank of the Fuel Reprocessing Plant at Tarapur to assess the accuracy of this method. The weight (or volume) of the solution in the tank could be measured independently with an accuracy of better than 0.5%. An experiment was also conducted to measure the total uranium in the accountability tank using MAGTRAP. The accuracy was better than 1%. The tracer technique was also used to arrive at optimum sparging times to ensure the homogeneity of the solution in the tank. Chemical procedures developed for the separation of plutonium and magnesium from dissolver solutions are also discussed. (author)

  8. Comparing the weight method and the use of the tracer Uranine for assessing pesticide drift on soils

    Science.gov (United States)

    Garcia-Santos, G.; Scheiben, D.; Leuenberger, F.; Binder, C. R.

    2009-04-01

    Drift from pesticide backpack-spraying is of major importance in the highlands of Colombia, where more than 20% be drifted by wind effects. This study assesses the usefulness of the weight method and the use of the tracer Uranine for assessing pesticide drift distribution on soils. The weight method has been used in developing countries and consists of weighing previously dried papers, installed close to the soil surface, before and after spraying a known amount of water. Relative humidity, temperature, direction and speed of the wind were monitored during the experiments. The tracer Uranine is often used for groundwater studies. Uranine was added to the water and sprayed by the farmer in the same way he would spray any pesticide mixture. The same papers used in the previous method were stored after the spraying and weighing. The tracer was extracted in water and analyzed using a fluorescent spectrometer. The advantage of Uranine over other tracers is its easy extraction with water and low detectable concentration. No solvents are required for the extraction. The experiments were performed during two months in the wet season in the region of Vereda la Hoya, Boyaca, Colombia at an altitude of 2800 m a.s.l., from September to October. Each experiment lasted about 30 min. The fast-changing meteorological conditions in the region affected the success of the weight method. The paper's weight was very sensitive to atmospheric high relative humidity and different evaporative conditions in grass and bare ground. Location of the blanks was essential and had to represent each of the different experimental evaporative conditions. Although the method was easy to implement, we consider that it is not appropriate for areas characterized by high evapotranspiration rates, and fast-changing climatic conditions as found in the Colombian highlands above 2800 m a.s.l. Whereas Uranine was not sensitive to different evapotranspiration rates nor fast changing climatic conditions, this

  9. On the self-diffusion process in liquid metals and alloys by the radioactive tracer method

    International Nuclear Information System (INIS)

    Ganovici, L.

    1978-01-01

    A theoretical and experimental study of self-diffusion process in liquid metals and alloys is presented. There are only a few pure metals for which diffusion coefficients in a liquid state are known. The thesis aims at increasing the number of liquid metals for which diffusion coefficients are available, by determining these values for liquids: Cd, Tl, Sb and Te. The self-diffusion coefficients of Te in some tellurium based liquid alloys such as Tl 2 Te, PbTe and Bi 90 Te 10 were also determined. Self-diffusion coefficients have been measured using two radioactive tracer methods: a) the capillary-reservoir method; b) the semi-infinite capillary method. The self-diffusion coefficients were derived from the measured radioactive concentration profile, using the solutions of Fick's second law for appropriate initial and limit conditions. The temperature dependence study of self-diffusion coefficients in liquids Cd, Tl, Sb and Te, was used to check some theoretical models on the diffusion mechanism in metallic melts. The experimental diffusion data interpreted in terms of the Arrhenius type temperature dependence, was used to propose two simple empiric relations for determining self diffusion coefficients of group I liquid metals and for liquid semi-metals. It was established a marked decrease of self-diffusion coefficients of liquid Te close to the solidification temperature. The diffusivity of Te in liquid Tl 2 Te points to an important decrease close to the solidification temperature. A simplified model was proposed for the diffusion structural unit in this alloy and the hard sphere model for liquid metals was checked by comparing the theoretical and experimental self-diffusion coefficients. (author)

  10. The new equation of steam quality and the evaluation of nonradioactive tracer method in PWR steam generators

    International Nuclear Information System (INIS)

    Ki Bang, Sung; Young Jin, Chang

    2001-01-01

    The performance of steam turbines is tested as ANSI/ASME-PTC 6. This code provides rules for the accurate testing of steam turbines for the purpose of obtaining the level of performance with a minimum uncertainty. Only the relevant portion of this code needs to process any individual case, In some case the procedure is simple. However, in complex turbines or complex operation modes, more procedures are required to test the involved provisions. Anyway, to measure the steam quality in the Wolsong PHWR with 4 SGs in Korea by the methods in the section ''Measure of steam quality methods'' of ANSI/ASME PTC 6, the result was not good though the steam generators are efficient. So, the new testing method was developed and the sophisticated equation of steam quality was introduced and uses the nonradioactive chemical tracer, Lithium hydroxide(LiOH) instead of the radioactive tracer, Na-24. (author)

  11. Atmospheric modeling to assess wind dependence in tracer dilution method measurements of landfill methane emissions.

    Science.gov (United States)

    Taylor, Diane M; Chow, Fotini K; Delkash, Madjid; Imhoff, Paul T

    2018-03-01

    The short-term temporal variability of landfill methane emissions is not well understood due to uncertainty in measurement methods. Significant variability is seen over short-term measurement campaigns with the tracer dilution method (TDM), but this variability may be due in part to measurement error rather than fluctuations in the actual landfill emissions. In this study, landfill methane emissions and TDM-measured emissions are simulated over a real landfill in Delaware, USA using the Weather Research and Forecasting model (WRF) for two emissions scenarios. In the steady emissions scenario, a constant landfill emissions rate is prescribed at each model grid point on the surface of the landfill. In the unsteady emissions scenario, emissions are calculated at each time step as a function of the local surface wind speed, resulting in variable emissions over each 1.5-h measurement period. The simulation output is used to assess the standard deviation and percent error of the TDM-measured emissions. Eight measurement periods are simulated over two different days to look at different conditions. Results show that standard deviation of the TDM- measured emissions does not increase significantly from the steady emissions simulations to the unsteady emissions scenarios, indicating that the TDM may have inherent errors in its prediction of emissions fluctuations. Results also show that TDM error does not increase significantly from the steady to the unsteady emissions simulations. This indicates that introducing variability to the landfill emissions does not increase errors in the TDM at this site. Across all simulations, TDM errors range from -15% to 43%, consistent with the range of errors seen in previous TDM studies. Simulations indicate diurnal variations of methane emissions when wind effects are significant, which may be important when developing daily and annual emissions estimates from limited field data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Method for assessment of stormwater treatment facilities - Synthetic road runoff addition including micro-pollutants and tracer.

    Science.gov (United States)

    Cederkvist, Karin; Jensen, Marina B; Holm, Peter E

    2017-08-01

    Stormwater treatment facilities (STFs) are becoming increasingly widespread but knowledge on their performance is limited. This is due to difficulties in obtaining representative samples during storm events and documenting removal of the broad range of contaminants found in stormwater runoff. This paper presents a method to evaluate STFs by addition of synthetic runoff with representative concentrations of contaminant species, including the use of tracer for correction of removal rates for losses not caused by the STF. A list of organic and inorganic contaminant species, including trace elements representative of runoff from roads is suggested, as well as relevant concentration ranges. The method was used for adding contaminants to three different STFs including a curbstone extension with filter soil, a dual porosity filter, and six different permeable pavements. Evaluation of the method showed that it is possible to add a well-defined mixture of contaminants despite different field conditions by having a flexibly system, mixing different stock-solutions on site, and use bromide tracer for correction of outlet concentrations. Bromide recovery ranged from only 12% in one of the permeable pavements to 97% in the dual porosity filter, stressing the importance of including a conservative tracer for correction of contaminant retention values. The method is considered useful in future treatment performance testing of STFs. The observed performance of the STFs is presented in coming papers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. An improved method for analysis of In-EDTA, I- and Br- used as active tracers in hydrological studies

    International Nuclear Information System (INIS)

    Stanescu, S.P.; Spiridon, S.

    1992-01-01

    Neutron activation analysis combined with chemical preconcentration of the elements in water samples can give a high sensitivity in the determination of concentrations for In-EDTA, I - and Br - used as active tracers in hydrological studies. The authors have developed an improved method of analysis which is sensitive, selective and applicable to a wide range of underground and surface water samples including those having a high concentration of manganese ions. (author) 6 refs.; 2 figs.; 1 tab

  14. Radioactive tracer method as an instrument for testing effectiveness of effluent treatment installations and mixing patterns in natural streams

    Energy Technology Data Exchange (ETDEWEB)

    Szpilowski, S; Strzelczak, G; Winnicki, R [Institute of Nuclear Research, Warsaw (Poland)

    1976-01-01

    The radiotracer methods of evaluation of sewage flow rate, testing of effluent treatment plants and mixing patterns in natural streams have been described. Experimental works were carried out for industrial installations and natural streams. As a tracer of liquid phase an aqueous KBr solution labelled with /sup 82/Br have been used. The sediment materials have been labelled with /sup 198/Au in the form of colloidal gold. The results of investigations have been utilized for treatment process analysis and water pollution control.

  15. Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

    International Nuclear Information System (INIS)

    Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

    1993-01-01

    The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

  16. Examination of tracer method using 43K produced with a cyclotron

    International Nuclear Information System (INIS)

    Yuida, Koichi; Kawarazaki, Yuji; Shibuya, Masao; Nozaki, Tadashi.

    1980-01-01

    The 43 K tracer produced with a cyclotron is contaminated with about the same amount of 42 K. During first 43 hours after the production, the rate of attenuation of its radioactivity was greater than the theoretical value of 43 K (half-life 22.4 hours) because of the rapid attenuation of radioactivity of the contaminating 42 K (half-life 12.4 hours). After that, however, the rate of attenuation in the radioactivity of 43 K tracer followed the attenuation curve of 22.4 hr half-life, i.e., the radioactivity of the contaminating 42 K was negligible. The potassium chloride fertilizer labelled with 43 K-tracer (or 42 K-tracer) was applied for 8 days (or 4.5 days in case of 42 K) to 2-month-old rice plants grown by hydroponics, and for 7 days to rice plants grown on soil (at ripening stage). The rice plants were then dried for 24 hours at 70 deg C, and the radioactivity was measured by a scintillation counter. 43 K was able to be traced for 13.3 days in the plants grown by hydroponics, and 42 K for 5.4 days, but 43 K was able to be traced only for 7.4 days in the plants grown on soil which absorb 43 K poorly. Since 43 K and 42 K are γ-ray emittors, and the energy is not low, microautoradiograms were not able to be made, but macroautoradiograms were made. The autoradiograms for 43 K and 42 K did not differ in resolution, and both were clear. The radioactivity of 43 K did not diminish so rapidly as 42 K, but was lost in one month. Such character of 43 K is beneficial both for tracer experiments and for the prevention of environmental pollution. (Kaihara, S.)

  17. Method of determining the characteristics of circulatory systems using tracer particles, making the particles and radioactive particles for use in the method

    International Nuclear Information System (INIS)

    Pratt, F.P.; Gagnon, D.L.

    1981-01-01

    In the method described tracer particles consist of ion exchange resin cores labelled with suitable radioactive ions or with a nuclide excitable by X-rays, and have a non-leaching polymeric coating. The particles are introduced into the system and are detected by visual inspection, radiation detection or X-ray fluorescence techniques. The cores are labelled using conventional batch ion exchange techniques. Coated tracers are produced by contacting a monomer, preferably furfuryl alcohol, with cores bearing catalytic ions (hydroxyl or hydrogen) on the surface which catalyse the monomer to form a polymer. The tracer particles in a physiologically acceptable liquid carrier are useful in clinical and medical investigations of blood flow. They can also be used for flow measurement in chemical process control streams. (U.K.)

  18. A radioactive tracer dilution method to determine the mass of molten salt

    International Nuclear Information System (INIS)

    Lei Cao; Jarrell, Josh; Hardtmayer, D.E.; White, Susan; Herminghuysen, Kevin; Kauffman, Andrew; Sanders, Jeff; Li, Shelly

    2017-01-01

    A new technique for molten salt mass determination, termed radioactive tracer dilution, that uses 22 Na as a tracer was validated at bench scale. It has been a challenging problem to determine the mass of molten salt in irregularly shaped containers, where a highly radioactive, high-temperature molten salt was used to process nuclear spent/used fuel during electrochemical recycling (pyro-processing) or for coolant/fuel salt from molten salt reactors. A radioactive source with known activity is dissolved into the salt. After a complete mixture, a small amount of the salt is sampled and measured in terms of its mass and radioactivity. By finding the ratio of the mass to radioactivity, the unknown salt mass in the original container can be precisely determined. (author)

  19. New application of the radioactive tracer method for sediment movement measurements in the surf zone

    International Nuclear Information System (INIS)

    Owczarczyk, A.; Strzelecki, M.; Szpilowski, S.; Wierzchnicki, R.; Basinski, T.

    1989-01-01

    The investigations of sediment movement with the use of radiotracers have been carried out in a surf zone of Lubiatowo. Inception of sand motion and sediment transport velocity were the objective of the experiment. The spider type construction was located at the depth of 0.7 m. An artificial sand made of iridium glass (γ = 2.660 kg/m 3 ) containing 0.25 weight per cent of 192 Ir was used as a tracer. The fraction of 0.15 to 0.20 mm has been chosen as the representative diameter of sand grains existing at the investigated bottom region. The inception of sand movement versus current velocity and wave conditions as well as displacement velocity of tracer mass were determined. An improved construction was designed and tested. (author)

  20. TU-AB-202-11: Tumor Segmentation by Fusion of Multi-Tracer PET Images Using Copula Based Statistical Methods

    International Nuclear Information System (INIS)

    Lapuyade-Lahorgue, J; Ruan, S; Li, H; Vera, P

    2016-01-01

    Purpose: Multi-tracer PET imaging is getting more attention in radiotherapy by providing additional tumor volume information such as glucose and oxygenation. However, automatic PET-based tumor segmentation is still a very challenging problem. We propose a statistical fusion approach to joint segment the sub-area of tumors from the two tracers FDG and FMISO PET images. Methods: Non-standardized Gamma distributions are convenient to model intensity distributions in PET. As a serious correlation exists in multi-tracer PET images, we proposed a new fusion method based on copula which is capable to represent dependency between different tracers. The Hidden Markov Field (HMF) model is used to represent spatial relationship between PET image voxels and statistical dynamics of intensities for each modality. Real PET images of five patients with FDG and FMISO are used to evaluate quantitatively and qualitatively our method. A comparison between individual and multi-tracer segmentations was conducted to show advantages of the proposed fusion method. Results: The segmentation results show that fusion with Gaussian copula can receive high Dice coefficient of 0.84 compared to that of 0.54 and 0.3 of monomodal segmentation results based on individual segmentation of FDG and FMISO PET images. In addition, high correlation coefficients (0.75 to 0.91) for the Gaussian copula for all five testing patients indicates the dependency between tumor regions in the multi-tracer PET images. Conclusion: This study shows that using multi-tracer PET imaging can efficiently improve the segmentation of tumor region where hypoxia and glucidic consumption are present at the same time. Introduction of copulas for modeling the dependency between two tracers can simultaneously take into account information from both tracers and deal with two pathological phenomena. Future work will be to consider other families of copula such as spherical and archimedian copulas, and to eliminate partial volume

  1. Standardized 15N tracer methods for the evaluation of the plasma protein turnover in clinical practice. 1

    International Nuclear Information System (INIS)

    Bornhak, H.

    1984-01-01

    Methods for quantitative isolation of plasma proteins or groups of proteins (total plasma or serum proteins, fibrin, total globulines, α, β, γ-globolines, albumin) are described based on combination of chromatography with precipitation and extraction techniques. These methods are adapted to the special requirements of 15 N analysis. They can be performed in clinic-chemical standard laboratories without special apparatuses or devices. The described procedures are the biochemico-analytical basis for the quantitative evaluation of tracer kinetics data by means of mathematic modelling. (author)

  2. TANGR2015 Heidelberg. Second international workshop on tracer applications of noble gas radionuclides in the geosciences

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    TANGR2015 is a workshop on the progress in the technique and application of Atom Trap Trace Analyis (ATTA). It is a follow-up to the first TANGR workshop, TANGR2012, which was held at the Argonne National Laboratory, Argonne, USA, in June 2012. It is organized in response to recent technical advances and new applications of Atom Trap Trace Analysis (ATTA), an analytical method for measuring the isotopes {sup 81}Kr, {sup 85}Kr, and {sup 39}Ar. The primary aim of the workshop is to discuss the technical progress of ATTA and thereby enable innovative and timely applications of the noble gas radionuclides to important scientific problems in earth and environmental sciences, e.g. in the fields of groundwater hydrology, glaciology, oceanography, and paleoclimatology.

  3. Use of K360Co(CN)6 and 114mInEDTA tracers determined by liquid scintillators method in hydrogeologic studies

    International Nuclear Information System (INIS)

    Lebecka, J.; Tomza, I.; Trzebicka, B.; Soltyk, W.

    1986-01-01

    The sensitive methods of K 3 60 Co(CN) 6 and 114m InEDTA tracers detection using the measurements by liquid scintillators method were elaborated to broaden the range of their use. The radiochemical separation of radioisotopes from investigated water samples and the measurement of their activity as well as double labelled samples are described. The practical uses of tracers are given. (A.S.)

  4. Tracer-based laser-induced fluorescence measurement technique for quantitative fuel/air-ratio measurements in a hydrogen internal combustion engine.

    Science.gov (United States)

    Blotevogel, Thomas; Hartmann, Matthias; Rottengruber, Hermann; Leipertz, Alfred

    2008-12-10

    A measurement technique for the quantitative investigation of mixture formation processes in hydrogen internal combustion engines (ICEs) has been developed using tracer-based laser-induced fluorescence (TLIF). This technique can be employed to fired and motored engine operation. The quantitative TLIF fuel/air-ratio results have been verified by means of linear Raman scattering measurements. Exemplary results of the simultaneous investigation of mixture formation and combustion obtained at an optical accessible hydrogen ICE are shown.

  5. Myth, Method and International News.

    Science.gov (United States)

    Lule, Jack

    Defining myth as a cultural narrative in symbolic form that articulates a world view and offers consensus with that view, this paper uses a brief "New York Times" report on the Soviet shooting down of South Korean airline flight 007 as the basis for comparison of international news and myth. Following a review of the literature on myth…

  6. Tracer techniques in microelectronics

    International Nuclear Information System (INIS)

    Flachowsky, J.; Freyer, K.

    1981-01-01

    Tracer technique and neutron activation analysis are capable of measuring impurities in semiconductor material or on the semiconductor surface in a very low concentration range. The methods, combined with autoradiography, are also suitable to determine dopant distributions in silicon. However, both techniques suffer from certain inherent experimental difficulties and/or limitations which are discussed. Methods of tracer technique practicable in the semiconductor field are described. (author)

  7. Reassessment of primed constant-infusion tracer method to measure urea kinetics

    International Nuclear Information System (INIS)

    Jahoor, F.; Wolfe, R.R.

    1987-01-01

    The validity of the primed constant-infusion tracer technique to make short-term measurements of urea production rates (R/sub a/) in humans in a physiological steady state and during disruption of steady state was evaluated. Four subjects received a primed constant infusion (P/I = 560 min) of [ 13 C]urea for 8 h. A plateau in urea enrichment was reached after 2 h and maintained throughout. When [ 13 C]- and [ 18 O]urea were simultaneously infused into four subjects at P/I ratios of 560:1 and 360:1, respectively, both tracers reached plateau enrichment at the same time (2-4 h). The enrichment at plateau was a function of the infusion rate rather than the priming dose, and calculated urea R/sub a/ was the same with either prime. In five additional experiments the technique responded acutely to a physiological perturbation (alanine infusion) in a dose-dependent manner. The results confirm that this technique is appropriate for short-term measurements of urea R/sub a/, and the requirement for accuracy in estimating the priming dose is not impractically stringent

  8. The constant rate injection tracer method - principle and application of a useful system for the investigation of single- and two-phase flows in thermal power plants

    International Nuclear Information System (INIS)

    Ederhof, A.; Lindberg, G.

    1985-01-01

    The ''tracer technique'', developed by Brown, Boveri and Company, permits measurement of water (liquid) mass flows, as part of the requested steam wetness, in steam turbine cycles. The additionally required steam mass flows can be calculated from mass flow balances (e.g. after condensation in a heater and subsequent measuring of the condensate flow) or energy balances. This measuring method is basically a dilution measurement using a radioactive or inactive tracer. If the radionuclide 24 Na is used, the measuring uncertainties will be typically 0.5-1.0%. The tracer technique was developed for largely automated parallel measurements on up to 30 lines of large capacity steam turbines. The example of the Ringhals 3 nuclear power plant illustrates that the tracer measuring method, applied during an acceptance test, yields better information on the functioning of the turbine cycle. (orig./GL) [de

  9. Suitability of tracers

    International Nuclear Information System (INIS)

    Klotz, D.

    1999-01-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other [de

  10. Aggregation Methods in International Comparisons

    NARCIS (Netherlands)

    B.M. Balk (Bert)

    2001-01-01

    textabstractThis paper reviews the progress that has been made over the past decade in understanding the nature of the various multilateral in- ternational comparison methods. Fifteen methods are discussed and subjected to a system of ten tests. In addition, attention is paid to recently developed

  11. Environmental Tracers

    Directory of Open Access Journals (Sweden)

    Trevor Elliot

    2014-10-01

    Full Text Available Environmental tracers continue to provide an important tool for understanding the source, flow and mixing dynamics of water resource systems through their imprint on the system or their sensitivity to alteration within it. However, 60 years or so after the first isotopic tracer studies were applied to hydrology, the use of isotopes and other environmental tracers are still not routinely necessarily applied in hydrogeological and water resources investigations where appropriate. There is therefore a continuing need to promote their use for developing sustainable management policies for the protection of water resources and the aquatic environment. This Special Issue focuses on the robustness or fitness-for-purpose of the application and use of environmental tracers in addressing problems and opportunities scientifically, to promote their wider use and to address substantive issues of vulnerability, sustainability, and uncertainty in (groundwater resources systems and their management.

  12. Tracer test method and process data reconciliation based on VDI 2048. Comparison of two methods for highly accurate determination of feedwater massflow at NPP Beznau

    International Nuclear Information System (INIS)

    Hungerbuehler, T.; Langenstein, M.

    2007-01-01

    The feedwater mass flow is the key measured variable used to determine the thermal reactor output in a nuclear power plant. Usually this parameter is recorded via venturi nozzles of orifice plates. The problem with both principles of measurement, however, is that an accuracy of below 1% cannot be reached. In order to make more accurate statements about the feedwater amounts recirculated in the water-steam cycle, tracer measurements that offer an accuracy of up to 0.2% are used. In the NPP Beznau both methods have been used in parallel to determine the feedwater flow rates in 2004 (unit 1) and 2005 (unit 2). Comparison of the results shows that a high level of agreement is obtained between the results of the reconciliation and the results of the tracer measurements. As a result of the findings of this comparison, a high level of acceptance of process data reconciliation based on VDI 2048 was achieved. (orig.)

  13. Sub-stoichiometric isotope dilution analysis method for the determination of iodine in common salts using iodine-131 tracer

    International Nuclear Information System (INIS)

    Singh, Vivek; Garg, A.N.

    1994-01-01

    A sub-stoichiometric isotope dilution analysis (SIDA) method was developed for the determination of iodine in different brands of common salts. An aqueous salt solution containing 131 I tracer and NaI as carrier is oxidized by tartaric acid and KIO 3 and the liberated iodine is extracted with CCl 4 . To the extract an aqueous solution of AgNO 3 is added in substoichiometric amount to obtain a colloidal solution of AgI. On adding sodium thiosulfate solution, the NaI so formed passes into aqueous solution, which is then counted. Several different brands of salt were analysed. The method is especially suitable for the determination of microgram amounts of iodide in the presence of excess of chloride. (Author)

  14. In Situ Tracer method for establishing the presence and predicting the activity of heavy metal-reducing microbes in the subsurface. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Hatfield, K.

    2003-07-01

    Tracer method to establish presence and distribution of chromium reducing microbes. The primary objective of this research was to establish an in situ tracer method for detecting the presence. distribution. and activity of subsurface heavy metal-reducing microorganisms. Research focused on microbial systems responsible for the reduction of chromium and a suite of biotracers coupled to the reduction process. The tracer method developed may be used to characterize sites contaminated with chromium or expedite bioremediation: and although research focused on chromium. the method can be easily extended to other metals, organics, and radionuclides. This brief final report contains three major sections. The first identifies specific products of the research effort such as students supported and publications. The second section briefly presents major research findings, while the last section summarizes the overall research effort.

  15. Assessing the Influence of Seasonal and Spatial Variations on the Estimation of Secondary Organic Carbon in Urban Particulate Matter by Applying the EC-Tracer Method

    Directory of Open Access Journals (Sweden)

    Sandra Wagener

    2014-04-01

    Full Text Available The elemental carbon (EC-tracer method was applied to PM10 and PM1 data of three sampling sites in the City of Berlin from February to October 2010. The sites were characterized by differing exposure to traffic and vegetation. The aim was to determine the secondary organic carbon (SOC concentration and to describe the parameters influencing the application of the EC-tracer method. The evaluation was based on comparisons with results obtained from positive matrix factorization (PMF applied to the same samples. To obtain site- and seasonal representative primary OC/EC-ratios ([OC/EC]p, the EC-tracer method was performed separately for each station, and additionally discrete for samples with high and low contribution of biomass burning. Estimated SOC-concentrations for all stations were between 11% and 33% of total OC. SOC-concentrations obtained with PMF exceeded EC-tracer results more than 100% at the park in the period with low biomass burning emissions in PM10. The deviations were besides others attributed to the high ratio of biogenic to combustion emissions and to direct exposure to vegetation. The occurrences of biomass burning emissions in contrast lead to increased SOC-concentrations compared to PMF in PM10. The obtained results distinguish that the EC-tracer-method provides well comparable results with PMF if sites are strongly influenced by one characteristic primary combustion source, but was found to be adversely influenced by direct and relatively high biogenic emissions.

  16. The International Double Taxation – Avoiding Methods

    OpenAIRE

    Nicoleta Barbuta-Misu

    2009-01-01

    The paper presents the main causes that determine double taxation, its forms, i.e. the economicdouble taxation and the international legal double taxation, the need for eliminating the double taxation andavoiding methods. In the presentation of the avoidance methods have been used practical examples forcomparison of the tax advantages for income beneficiary between: the total exemption method andprogressive exemption method, on the one hand, and total crediting method and ordinary crediting m...

  17. Tax optimization methods of international companies

    OpenAIRE

    Černá, Kateřina

    2015-01-01

    This thesis is focusing on methods of tax optimization of international companies. These international concerns are endeavoring tax minimization. The disparity of the tax systems gives to these companies a possibility of profit and tax base shifting. At first this thesis compares the differences of tax optimization, aggressive tax planning and tax evasion. Among the areas of the optimization methods, which are described in this thesis, belongs tax residention, dividends, royalty payments, tra...

  18. Proposal for a coordination research programme (CRP) of the International Atomic Energy Agency (IAEA) on stable isotope tracer techniques for studies on protein-energy interactions

    International Nuclear Information System (INIS)

    Shetty, P.; James, W.P.T.

    1993-01-01

    This Report provides a rationale and justification for the initiation of a Coordinated Research programme to support studies using stable isotopic tracer techniques to address priority areas of human protein-energy interactions with special emphasis on the problems of human nutrition in developing countries. The Report suggests a modus for establishing such a practically oriented Coordinated Research Programme under the aegis of the International Atomic Energy Agency with concrete suggestions for its organization and the identification of probable participants in such a programme. The likely sources of additional funding to sustain such an activity viable for a period of 4 to 5 years are also indicated. 8 refs

  19. Journal: Efficient Hydrologic Tracer-Test Design for Tracer ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed to facilitate the design of tracer tests by root determination of the one-dimensional advection-dispersion equation (ADE) using a preset average tracer concentration which provides a theoretical basis for an estimate of necessary tracer mass. The method uses basic measured field parameters (e.g., discharge, distance, cross-sectional area) that are combined in functional relatipnships that descrive solute-transport processes related to flow velocity and time of travel. These initial estimates for time of travel and velocity are then applied to a hypothetical continuous stirred tank reactor (CSTR) as an analog for the hydrological-flow system to develop initial estimates for tracer concentration, tracer mass, and axial dispersion. Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to be necessary for descri

  20. The International Double Taxation – Avoiding Methods

    Directory of Open Access Journals (Sweden)

    Nicoleta Barbuta-Misu

    2009-06-01

    Full Text Available The paper presents the main causes that determine double taxation, its forms, i.e. the economicdouble taxation and the international legal double taxation, the need for eliminating the double taxation andavoiding methods. In the presentation of the avoidance methods have been used practical examples forcomparison of the tax advantages for income beneficiary between: the total exemption method andprogressive exemption method, on the one hand, and total crediting method and ordinary crediting method,on the other hand, but the comparing of tax reduction between methods of exemption and crediting.

  1. Measurement of cardiovascular function using a novel view-sharing PET reconstruction method and tracer kinetic analysis

    Directory of Open Access Journals (Sweden)

    Paul R. Territo

    2016-10-01

    Full Text Available Abstract Recent advancements in PET instrumentation have made the non-invasive assessment of cardiovascular function in small animals a reality. The majority of small animal PET systems use stationary detector gantries, thus affording high temporal resolution imaging of cardiac function. Systems designed to maximize spatial resolution and detection sensitivity employing rotating gantry designs are suboptimal when high temporal resolution imaging is needed. To overcome this limitation, the current work developed a novel view-sharing data analysis scheme suitable for dynamic cardiac PET imaging using 18F-NaF as the tracer and tracer kinetic model analysis. This scheme was tested in a rat model of cardiovascular function where the relationship between direct transonic flow measures of cardiac output were highly correlated (f(x = 1.0216x − 24.233, R = 0.9158, p < 0.001 with the new model. Similarly, derived measures of stroke volume were also highly correlated (f(x = 0.9655x − 0.0428, R = 0.9453, p < 0.001 with the current approach. Administration of xylazine caused a statistically significant increase in stroke volume (0.32 ± 0.07 ml, p = 0.003, n = 4 and a significant decrease in both heart rate (−155 ± 7.1 beats/min, p < 0.001, n = 4 and cardiac output (−75.9 ± 23.0 ml/kg min, p = 0.01, n = 4. These findings suggest that the new sinogram binning and kinetic modeling methods produce reliable cardiac function measures suitable for longitudinal monitoring of cardiovascular function.

  2. Boundary element method for internal axisymmetric flow

    Directory of Open Access Journals (Sweden)

    Gokhman Alexander

    1999-01-01

    Full Text Available We present an accurate fast method for the computation of potential internal axisymmetric flow based on the boundary element technique. We prove that the computed velocity field asymptotically satisfies reasonable boundary conditions at infinity for various types of inlet/exit. Computation of internal axisymmetric potential flow is an essential ingredient in the three-dimensional problem of computation of velocity fields in turbomachines. We include the results of a practical application of the method to the computation of flow in turbomachines of Kaplan and Francis types.

  3. Statistical data analysis method for multi-zonal airflow measurement using multiple kinds of perfluorocarbon tracer gas

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, Hiroyasu; Onishi, Yoshinori [Institute of Technology, Shimizu Corporation, 4-17, Etchujima 3-chome, Koto-ku, Tokyo 135-8530 (Japan); Tanabe, Shin-ichi [School of Science and Engineering, Department of Architecture, Waseda University, 3-4-1 Okubo, Shinjyuku-ku, Tokyo 169-8555 (Japan); Kashihara, Seiichi [R and D Laboratories, Asahi Kasei Homes Corporation, 2-1, Samejima Fuji-shi, Shizuoka 416-8501 (Japan)

    2009-03-15

    Conventional multi-zonal ventilation measurement methods by multiple types of perfluorocarbon tracers use a number of different gases equal to the number of zones (n). The possible n x n+n airflows are estimated from the mass balance of the gases and the airflow balance. However, some airflows may not occur because of inter-zonal geometry, and the introduction of unnecessary, unknown parameters can impair the accuracy of the estimation. Also, various error factors often yield an irrational negative airflow rate. Conventional methods are insufficient for the evaluation of error. This study describes a way of using the least-squares technique to improve the precision of estimation and to evaluate reliability. From the equations' residual, the error variance-covariance matrix {lambda}{sub q} of the estimated airflow rate error is deduced. In addition, the coefficient of determinant using the residual sum of squares and total variation is introduced. Furthermore, the error matrix{sub m}{lambda}{sub q} from the measurement errors in the gas concentration and gas emission rate is deduced. The discrepancy ratio of the model premises is defined by dividing the diagonal elements of the former by those of the latter. Moreover, the index of irrationality of the estimated negative airflow rate is defined, based on the different results of the three estimation methods. Some numerical experiments are also carried out to verify the flow rate estimation and the reliability evaluation theory. (author)

  4. Method for Determination of Neptunium in Large-Sized Urine Samples Using Manganese Dioxide Coprecipitation and 242Pu as Yield Tracer

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    A novel method for bioassay of large volumes of human urine samples using manganese dioxide coprecipitation for preconcentration was developed for rapid determination of 237Np. 242Pu was utilized as a nonisotopic tracer to monitor the chemical yield of 237Np. A sequential injection extraction chr...... and rapid analysis of neptunium contamination level for emergency preparedness....

  5. Study on adsorption of activated carbon fiber to background-level xenon in air by the method of 133Xe tracer

    International Nuclear Information System (INIS)

    Zhang Haitao; Wang Yalong; Zhang Lixing; Wang Xuhui; Zhang Xiaolin

    2001-01-01

    The adsorption behaviors of the different activated carbon fibers to ultra-trace xenon in air are studied using the method of 133 Xe as tracer. The efficiency equation of adsorption columns are determined. The comparison of adsorptive capacity between activated carbon fibers and activated carbon indicates that activated carbon fibers are better than activated carbon under low temperature

  6. TRACER - TRACING AND CONTROL OF ENGINEERING REQUIREMENTS

    Science.gov (United States)

    Turner, P. R.

    1994-01-01

    TRACER (Tracing and Control of Engineering Requirements) is a database/word processing system created to document and maintain the order of both requirements and descriptive material associated with an engineering project. A set of hierarchical documents are normally generated for a project whereby the requirements of the higher level documents levy requirements on the same level or lower level documents. Traditionally, the requirements are handled almost entirely by manual paper methods. The problem with a typical paper system, however, is that requirements written and changed continuously in different areas lead to misunderstandings and noncompliance. The purpose of TRACER is to automate the capture, tracing, reviewing, and managing of requirements for an engineering project. The engineering project still requires communications, negotiations, interactions, and iterations among people and organizations, but TRACER promotes succinct and precise identification and treatment of real requirements separate from the descriptive prose in a document. TRACER permits the documentation of an engineering project's requirements and progress in a logical, controllable, traceable manner. TRACER's attributes include the presentation of current requirements and status from any linked computer terminal and the ability to differentiate headers and descriptive material from the requirements. Related requirements can be linked and traced. The program also enables portions of documents to be printed, individual approval and release of requirements, and the tracing of requirements down into the equipment specification. Requirement "links" can be made "pending" and invisible to others until the pending link is made "binding". Individuals affected by linked requirements can be notified of significant changes with acknowledgement of the changes required. An unlimited number of documents can be created for a project and an ASCII import feature permits existing documents to be incorporated

  7. International Conference eXtended Discretization MethodS

    CERN Document Server

    Benvenuti, Elena

    2016-01-01

    This book gathers selected contributions on emerging research work presented at the International Conference eXtended Discretization MethodS (X-DMS), held in Ferrara in September 2015. It highlights the most relevant advances made at the international level in the context of expanding classical discretization methods, like finite elements, to the numerical analysis of a variety of physical problems. The improvements are intended to achieve higher computational efficiency and to account for special features of the solution directly in the approximation space and/or in the discretization procedure. The methods described include, among others, partition of unity methods (meshfree, XFEM, GFEM), virtual element methods, fictitious domain methods, and special techniques for static and evolving interfaces. The uniting feature of all contributions is the direct link between computational methodologies and their application to different engineering areas.

  8. Behavior of water of crystallization in CuSO4·5H2O studied by the tritium tracer method

    International Nuclear Information System (INIS)

    Sato, Tetsuya; Jiao, Yurong; Imaizumi, Hiroshi; Kano, Naoki

    2011-01-01

    Tritium (T) is one of hydrogen isotopes, and its chemical behavior is similar to other hydrogen isotopes. Therefore tritium is used as one of tracers in chemical experimental tracer. As one of applications, we tried to apply this method to clarifying the behavior of water of crystallization in an inorganic material. The sample used was copper sulfate pentahydrate. First, this compound was tritiated, then desorbed the water of crystallization from the tritiated compound. Comparing the behavior of amount of substance with the specific activity, the following four matters have been found. (1) There is no relation between each T concentration of HTO water and the mass of the compound within the T concentration used. (2) It can be confirmed that copper sulfate pentahydrate has three kinds of energetically different water of crystallization by T tracer method. (3) Each T concentration of water of crystallization is different at the coordinate position, and the HTO molecule is hard to coordinate at the position having weak binding force. (4) The T tracer method is useful to analyze the behavior of the combined water in materials. (author)

  9. Synaptic neurochemistry: Potential targets for the development of new tracer imaging methods

    International Nuclear Information System (INIS)

    Frey, K.A.

    1991-01-01

    Radiotracer techniques for measuring biochemical and pharmacologic processes unique to the synapse and to chemically defined neuronal populations are now under investigation. These methods make use of neuronal biochemical specializations determined by invasive animal experiments and confirmed by human biopsy and autopsy. Early investigators focused on determination of neurotransmitter receptors. More recently, attention has turned to evaluation of presynaptic markers such as steps in neurotransmitter synthesis, storage and degradation, and to the potential evaluation of new postsynaptic markers, including chemical second-messenger activities and receptor-grated ion channel distributions. In this review, synaptic neurochemistry is presented with attention to potential radiotracer imaging methods. Strategies for selecting and applying neuropharmacologic methods to disorders of the human brain are outlined. The methodological requirements of new radiotracer imaging techniques are summarized according to their desired application. Finally, distinctions between in vitro and in vivo measurements of these processes are outlined, along with strategies for detecting such differences

  10. Systems identification: a theoretical method applied to tracer kinetics in aquatic microcosms

    International Nuclear Information System (INIS)

    Halfon, E.; Georgia Univ., Athens

    1974-01-01

    A mathematical model of radionuclide kinetics in a laboratory microcosm was built and the transfer parameters estimated by multiple regression and system identification techniques. Insight into the functioning of the system was obtained from analysis of the model. Methods employed have allowed movements of radioisotopes not directly observable in the experimental systems to be distinguished. Results are generalized to whole ecosystems

  11. Nuclear method for determination of nitrogen depth distributions in single seeds. [/sup 14/N tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Sundqvist, B; Gonczi, L; Koersner, I; Bergman, R; Lindh, U

    1974-01-01

    (d,p) reactions in /sup 14/N were used for probing single kernels of seed for nitrogen content and nitrogen depth distributions. Comparison with the Kjeldahl method was made on individual peas and beans. The results were found to be strongly correlated. The technique to obtain depth distributions of nitrogen was also used on high- and low-lysine varieties of barley for which large differences in nitrogen distributions were found.

  12. 4D-SPECT/CT in orthopaedics: a new method of combined quantitative volumetric 3D analysis of SPECT/CT tracer uptake and component position measurements in patients after total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, Helmut; Falkowski, Anna L.; Forrer, Flavio [Kantonsspital Baselland, Institute for Radiology and Nuclear Medicine, Bruderholz (Switzerland); Henckel, Johann [Imperial College London, London (United Kingdom); Hirschmann, Michael T. [Kantonsspital Baselland, Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland)

    2013-09-15

    The purpose was to evaluate the intra- and inter-observer reliability of combined quantitative 3D-volumetric single-photon emission computed tomography (SPECT)/CT analysis including size, intensity and localisation of tracer uptake regions and total knee arthroplasty (TKA) position. Tc-99m-HDP-SPECT/CT of 100 knees after TKA were prospectively analysed. The anatomical areas represented by a previously validated localisation scheme were 3D-volumetrically analysed. The maximum intensity was recorded for each anatomical area. Ratios between the respective value and the mid-shaft of the femur as the reference were calculated. Femoral and tibial TKA position (varus-valgus, flexion-extension, internal rotation- external rotation) were determined on 3D-CT. Two consultant radiologists/nuclear medicine physicians interpreted the SPECT/CTs twice with a 2-week interval. The inter- and intra-observer reliability was determined (ICCs). Kappa values were calculated for the area with the highest tracer uptake between the observers. The measurements of tracer uptake intensity showed excellent inter- and intra-observer reliabilities for all regions (tibia, femur and patella). Only the tibial shaft area showed ICCs <0.89. The kappa values were almost perfect (0.856, p < 0.001; 95 % CI 0.778, 0.922). For measurements of the TKA position, there was strong agreement within and between the readings of the two observers; the ICCs for the orientation of TKA components for inter- and intra-observer reliability were nearly perfect (ICCs >0.84). This combined 3D-volumetric standardised method of analysing the location, size and the intensity of SPECT/CT tracer uptake regions (''hotspots'') and the determination of the TKA position was highly reliable and represents a novel promising approach to biomechanics. (orig.)

  13. A study on hepato-biliary and alimentary scintigram by means of triple tracer method

    International Nuclear Information System (INIS)

    Aibata, Hirofumi; Torizumi, Kazutami; Okada, Takashi; Kiji, Shigeyuki; Yamada, Ryusaku; Shimada, Kosuke; Taniguchi, Katsutoshi; Aoki, Yozo

    1987-01-01

    In order to evaluate the gastric emptying and postprandial mixing of bile with food, the scintigraphies of hepatobiliary and gastrointestinal tracts by using three different kinds of radioisotopes were performed simultaneously ( 99m Tc-E · HIDA for hepatobiliary scintigraphy, 111 In-DTPA containing orange juice and 131 I-albumin containing scrambled egg for gastrointestinal scintigraphy). This method was available for observation of gastric emptying of liquid and solid foods and also examination of the mixing effect of bile and food quantitatively. (author)

  14. Calculation method of passive tracer using regional ocean modeling system (ROMS)

    International Nuclear Information System (INIS)

    Tubono, Takaki; Tsumune, Daisuke; Misumi, Kazuhiro; Yoshida, Yoshikatsu

    2010-01-01

    A dose assessments method for packages shipping radioactive materials was developed to calculate concentrations of radioactive materials discharged from the hypothetically sinking point using Regional Ocean Modeling System (ROMS). The programs of ROMS were improved for simultaneously calculating the flow fields around Japan and the concentrations discharged from several bottom points in the continental shelf. The model domain covered the northeast pacific region around Japan, 20degN-65degN, 120degE-165degE, with 1/10 degree horizontal resolution and 30 sigma-levels. The ROMS model captured main features such as Kuroshio currents, including the separation location and the Kuroshio extension, and Oyashio currents. The calculated volume transports through the main straits such as Tokara strait, Tsushima strait and Tsugaru strait were compared well to the measured or estimated that. The calculated concentrations discharged from 12 bottom points showed mixing associated with the eddies of ocean currents. This method is available to evaluate effectively the concentrations of radioactive materials only by setting the subsidence location and the concentrations and volume discharged. (author)

  15. Quantification of cell death in developing cerebellum by a 14C tracer method

    International Nuclear Information System (INIS)

    Griffin, W.S.; Woodward, D.J.; Chanda, R.

    1978-01-01

    To study the question of whether or not cell death contributes significantly to normal or stressed postnatal brain development in a way which is biochemically quantifiable, we carried out an experiment to assess the amount of cell death in developing cerebellum. By measuring the loss of DNA content and the loss of 14 C from labelled thymidine previously incorporated into the DNA fraction (DNAF) in X-irradiated neonatal animals, shown by histological methods to have cell death to the degree of degranulating the external granular layer (EGL), we showed that when cells die both label and DNA content are greatly decreased in the cerebellum. Experiments on both normal and malnourished animals showed that cell death does not contribute significantly to cerebellar development in either malnutrition-stressed or normal animals. Here, we present a biochemical tool for assessing cell death and evidence that cell death does not contribute significantly to cerebellar development

  16. Regeneration of unmyelinated and myelinated sensory nerve fibres studied by a retrograde tracer method

    DEFF Research Database (Denmark)

    Lozeron, Pierre; Krarup, Christian; Schmalbruch, Henning

    2004-01-01

    cells that had been labelled, i.e., that had regenerated axons towards or beyond the injection site, were counted in serial sections. Large and small neurons with presumably myelinated and unmyelinated axons, respectively, were classified by immunostaining for neurofilaments. The axonal growth rate......Regeneration of myelinated and unmyelinated sensory nerve fibres after a crush lesion of the rat sciatic nerve was investigated by means of retrograde labelling. The advantage of this method is that the degree of regeneration is estimated on the basis of sensory somata rather than the number...... of axons. Axonal counts do not reflect the number of regenerated neurons because of axonal branching and because myelinated axons form unmyelinated sprouts. Two days to 10 weeks after crushing, the distal sural or peroneal nerves were cut and exposed to fluoro-dextran. Large and small dorsal root ganglion...

  17. Method of moments analysis of the Twin Lake tracer test data

    International Nuclear Information System (INIS)

    Moltyaner, G.L.; Wills, C.A.

    1987-09-01

    The two-dimensional transport of radioiodine at the Twin Lake aquifer at CRNL, is investigated at the full-aquifer-thickness scale using curve fitting procedures and the method of statistical moments. The observed concentration-time data were analysed using temporal moments and were converted to concentration-distance data sets. The converted data were then analysed using spatial moments and curve fitting procedures. It was concluded that over the 40 m flow path the areal two-dimensional model of mean concentration distribution does not adequately describe the essentially three-dimensional nature of the dispersion process probably because of the relatively short travel distances compared to the full-aquifer-thickness scale of description of the transport process (∼ 10 m). Much larger travel distances are required before the effect of irregular flow geometry at this scale is smoothed out. Based on the previous analysis of the dispersion process at the macroscopic scale of descriptions of the transport processes it was concluded that the macroscopic scale characteristics, to a large extent, possess a universal character and the macroscopic-scale dispersion model adequately describes the field-scale dispersion process. 20 refs

  18. Triacylglycerol secretion in rats: validation of a tracer method employing radioactive glycerol

    International Nuclear Information System (INIS)

    Bird, M.; Williams, M.A.; Baker, N.

    1984-01-01

    A two-compartment model was developed to analyze the temporal changes in plasma triacylglycerol (TG)-specific radioactivity after injection of [2- 3 H]glycerol into rats. The analysis, which yielded fractional rate constants of TG secretion, was tested in rats fed diets either adequate or deficient in essential fatty acids (EFA) and containing either glucose, fructose or sucrose as the dietary carbohydrate. The method of analysis appeared valid, first, because of a close agreement between experimental and computer-fitted TG-specific radioactivity curves, and second, because the fractional rate constants obtained were quite similar to fractional rate constants determined previously by the Triton WR-1339 technique in rats maintained on identical diets. The results show that EFA deficiency increased the fractional rate constant of TG secretion 1.7-, 1.8- and 3.3-fold and the rate of TG secretion 1.8-, 1.6- and 1.4-fold when the dietary carbohydrate was glucose, sucrose and fructose, respectively, in comparison with control rats fed diets supplying these same carbohydrates but adequate in EFA. In the latter groups, the rates of plasma TG secretion were in the range of 0.14-0.17 mg/min per 100 g body weight, and the rate of secretion in the fructose-fed rats was only 20% higher than in the glucose-fed rats

  19. Detection method of internal leakage from valve using acoustic method

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Kitajima, Akira; Suzuki, Akio.

    1990-01-01

    The objective of this study is to estimate the feasibility of the acoustic method for the internal leakage from the valves in power plants. From the experimental results, it was suggested that the acoustic method for the monitoring of leakage was feasible. When the background levels are higher than the acoustic signals from leakage, we can detect the leakage analyzing the spectrum of the remainders which take the background noise from the acoustic signals. (author)

  20. Boundary integral method application in the transportation modeling of radioactive tracers in porous ways; Aplicacao do metodo da integral de contorno na modelagem do transporte de tracadores radioativos em meios porosos

    Energy Technology Data Exchange (ETDEWEB)

    Ferroni, Jose Geraldo

    1996-03-01

    This work describes a method for estimating the effluent concentrations of radioactive tracers in production wells, considering well to well injection tests and piston-like displacements of fluids in the reservoir. The model for tracer transportation takes into account effects of convection and hydrodynamic dispersion. (author)

  1. Tracer research in process engineering

    International Nuclear Information System (INIS)

    Iller, E.

    1992-01-01

    The book is a review of modern applications of tracer techniques in chemical and process engineering studies. The next topics have been extensively presented: 1) media flow through apparatus; 2) the tracers in the study of media flow dynamics through apparatus; 3) mathematical interpretation of experimental data from impulse-response method; 4) the models of media flow through chemical reactors and apparatus; 5) radiotracers in mass transport study; 6) examples of practical applications of tracer methods in industrial objects. 84 refs, 96 figs, 31 tabs

  2. Tracer dispersion - experiment and CFD

    International Nuclear Information System (INIS)

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  3. A nonequilibrium simulation method for calculating tracer diffusion coefficients of small solutes in n-alkane liquids and polymers

    NARCIS (Netherlands)

    van der Vegt, N.F.A.; Briels, Willem J.; Wessling, Matthias; Strathmann, H.

    1998-01-01

    The tracer diffusion coefficients of methane in n-alkane liquids of increasing chain length were calculated by measuring the friction from short time nonequilibrium molecular dynamics simulations. The frictional constant was calculated from the exponentially decaying distance between two methane

  4. Internal Dosimetry Intake Estimation using Bayesian Methods

    International Nuclear Information System (INIS)

    Miller, G.; Inkret, W.C.; Martz, H.F.

    1999-01-01

    New methods for the inverse problem of internal dosimetry are proposed based on evaluating expectations of the Bayesian posterior probability distribution of intake amounts, given bioassay measurements. These expectation integrals are normally of very high dimension and hence impractical to use. However, the expectations can be algebraically transformed into a sum of terms representing different numbers of intakes, with a Poisson distribution of the number of intakes. This sum often rapidly converges, when the average number of intakes for a population is small. A simplified algorithm using data unfolding is described (UF code). (author)

  5. Principle of cerebral hemodynamic perfusion in SPECT and new evaluation method of hemodynamic reserve capacity using {sup 99m}Tc tracer

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Masaaki; Mukai, Hironobu; Tada, Motoyuki; Miyazaki, Yoshiharu; Takimoto, Masamori; Shiozaki, Jun; Inoue, Hisashi [Noto General Hospital, Nanao, Ishikawa (Japan)

    2002-07-01

    We performed quantitative measurements of cerebral blood flow (CBF) using {sup 99m}Tc tracer by the Patlak Plot method with reference to normal aging and cerebrovascular reserve (CVR) capacity and then investigated a new evaluation method of CVR. Aging and decrease of ADL were significantly associated with reduction of the mean hemispheric CBF. In the acetazolamide (ACZ) stress test, these retrospective data showed some overlap in each ischemic grade on the relationship between rCBF and CVR response for the predictability of EC/IC bypass surgery. In these controversial problems, we must reconfirm the principle of cerebral hemodynamic perfusion in SPECT. First, retention tracer is distributed via the microcirculatory system to brain tissue. Second, therefore, we should understand not only the circulation of major vessels, but also the dynamics and rheology in parenchymal microcirculation to determine brain SPECT and CVR capacity. In the next step, we approached the new evaluation method of CVR capacity using {sup 99m}Tc tracer by a serial dynamic SPECT with a slip-ring rotational gamma camera. These preliminally findings suggest that a serial dynamic SPECT may be more useful for analyzing the pathophysiology on brain circulation and CVR than conventional approaches. (author)

  6. Separation of input function for rapid measurement of quantitative CMRO2 and CBF in a single PET scan with a dual tracer administration method

    International Nuclear Information System (INIS)

    Kudomi, Nobuyuki; Watabe, Hiroshi; Hayashi, Takuya; Iida, Hidehiro

    2007-01-01

    Cerebral metabolic rate of oxygen (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood flow (CBF) images can be quantified using positron emission tomography (PET) by administrating 15 O-labelled water (H 15 2 O) and oxygen ( 15 O 2 ). Conventionally, those images are measured with separate scans for three tracers C 15 O for CBV, H 15 2 O for CBF and 15 O 2 for CMRO 2 , and there are additional waiting times between the scans in order to minimize the influence of the radioactivity from the previous tracers, which results in a relatively long study period. We have proposed a dual tracer autoradiographic (DARG) approach (Kudomi et al 2005), which enabled us to measure CBF, OEF and CMRO 2 rapidly by sequentially administrating H 15 2 O and 15 O 2 within a short time. Because quantitative CBF and CMRO 2 values are sensitive to arterial input function, it is necessary to obtain accurate input function and a drawback of this approach is to require separation of the measured arterial blood time-activity curve (TAC) into pure water and oxygen input functions under the existence of residual radioactivity from the first injected tracer. For this separation, frequent manual sampling was required. The present paper describes two calculation methods: namely a linear and a model-based method, to separate the measured arterial TAC into its water and oxygen components. In order to validate these methods, we first generated a blood TAC for the DARG approach by combining the water and oxygen input functions obtained in a series of PET studies on normal human subjects. The combined data were then separated into water and oxygen components by the present methods. CBF and CMRO 2 were calculated using those separated input functions and tissue TAC. The quantitative accuracy in the CBF and CMRO 2 values by the DARG approach did not exceed the acceptable range, i.e., errors in those values were within 5%, when the area under the curve in the input function of the second tracer

  7. Radioactive tracers in Sedimentology

    International Nuclear Information System (INIS)

    Rodrigues, H.T.

    1973-01-01

    First is given a broad description of the uses of radioactive tracers in Sedimentology. The general method is established, including determinations of probability and standard deviation. Following are determined: the response law of the detector, the minimum mass for statistical detection, and the minimum mass for dynamic detection. The granularity is an important variable in these calculations. Final conclusions are given, and results are compared with existing theories

  8. Proceedings of the atmospheric tracers and tracer application workshop

    International Nuclear Information System (INIS)

    Barr, S.; Gedayloo, T.

    1979-12-01

    In addition to presentations by participating members a general discussion was held in order to summarize and outline the goals and objectives of the workshop. A number of new low level background tracers such as heavy methanes, perfluorocarbons, multiply labeled isotopes such as 13 C 18 O 2 , helium 3, in addition to sample collection techniques and analytical methods for various tracers were discussed. This report is a summary of discussions and papers presented at this workshop

  9. Detection method of internal leakage from valve using acoustic method

    International Nuclear Information System (INIS)

    Kumagai, Horomichi

    1990-01-01

    The purpose of this study is to estimate the availability of acoustic method for detecting the internal leakage of valves at power plants. Experiments have been carried out on the characteristics of acoustic noise caused by the leak simulated flow. From the experimental results, the mechanism of the acoustic noisegenerated from flow, the relation between acoustic intensity and leak flow velocity, and the characteristics of the acoustic frequency spectrum were clarified. The acoustic method was applied to valves at site, and the background noises were measured in abnormal plant conditions. When the background level is higher than the acoustic signal, the difference between the background noise frequency spectrum and the acoustic signal spectrum provide a very useful leak detection method. (author)

  10. The development of in vivo tracer methods to obtain new information about human disease: a study of the hallucinating brain

    International Nuclear Information System (INIS)

    Jones, T.; Silbersweig, D.A.; Stern, E.; Schnorr, L.; Seaward, J.; Clark, J.C.; Lammertsma, A.A.; Grootoonk, S.

    1996-01-01

    An outline is provided of the development of methodological strategies to address the question of focal cerebral activation during hallucinations in schizophrenic patients. In so doing, the innovation and diligence required to tailor in vivo tracer procedures to specific clinical research issues are highlighted. Attention is drawn to the complexity of methodological advances and the way in which they are based upon close scientific and technical collaboration between clinical scientists, and non-clinical scientists and research support staff. (orig.). With 1 fig

  11. Method for the detection of Tc in seaweed samples coupling the use of Re as a chemical tracer and isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Mas, Jose Luis; Tagami, Keiko; Uchida, Shigeo

    2004-01-01

    Analysis of the artificial radionuclide 99 Tc in environmental samples requires a chemical separation due to its low concentration, and therefore the use of a chemical yield tracer is peremptory. From a practical viewpoint, Re can be used for this purpose, due to its chemical similarities with Tc. Thus, the use of a radioactive tracer for Tc recovery calculation can be avoided. However, results from a recent intercomparison exercise showed that using of Re as a chemical yield tracer appears to underestimate the Tc concentration relative to the result obtained with isotopes of Tc. In the present work, the methodology used to design a simple separation method for the measurement of 99 Tc in environmental samples is described. Tc recovery is estimated throughout the Re recovery calculation by the isotope dilution technique coupled with ICP-MS (ID-ICP-MS) technique. For chemical separation, a chromatographic resin is used. Interfering elements are removed using a resin washing step carefully designed to avoid any element fractionation between Re and Tc; the care taken in this step is of major importance to assure the equivalence of the chemical recoveries for both elements. Agreement is tested using five replicates of five seaweed samples. The average recoveries for 95m Tc and Re were 93±6 and 95±7%, respectively, those are within the uncertainty intervals for each other. The results explained here demonstrate the possibility of applying Re chemical recoveries to calculate the Tc concentrations with the advantage of not introducing systematic errors

  12. Potential Use of Tracer Methods, Especially Autoradiography, in the Study of the Relation of Herbicides to Soil Biology

    Energy Technology Data Exchange (ETDEWEB)

    Grossbard, E. [Grassland Research Institute, Hurley, Maidenhead, Berks (United Kingdom)

    1966-05-15

    Several tracer methods, designed originally for the study of general soil processes, are described. Their possible adaptation to investigations of the interaction of herbicides with soil biology (especially the soil microflora) is discussed. Rapid disposal of the herbicide-treated vegetation before replanting (minimal tillage) is essential. In comparing the efficiency of herbicidal destruction of vegetation with conventional ploughing, and also when evaluating the effect of various herbicides on the rate of decay of the treated crops, a method is required to measure the rate of the microbial decomposition of the plant residues. A technique based on autoradiography is described which makes possible the study of the progressive decay of herbage grasses and rye uniformly labelled with carbon-14, placed on the surface of soil and incubated for various periods of time. Photoelectric measurements of the density of images of autoradiographs prepared before the start of the experiment and at intervals during incubation show a statistically significant decrease in density with time of incubation. This progressive loss of carbon is an estimate of the rate of decomposition of the residues. The utilization of breakdown products of herbicides by micro-organisms has been demonstrated in pure culture using labelled herbicides but not directly in the soil. A method based on the stripping film technique demonstrates the incorporation of carbon-14 atoms into the cell material of fungi which decomposed {sup 14}C-labelled plant residues mixed with soil. This technique could be adapted to study the uptake of labelled atoms after the microbial decomposition of radioactive herbicides in the soil. Herbicides inhibit and under,certain conditions may also stimulate the growth of micro-organisms in the soil. The evolution of CO{sub 2} is frequently used as an index of microbial activity. It is, however, also a function of the carbon content of the soil. Soils not treated with herbicides will

  13. Internal Error Propagation in Explicit Runge--Kutta Methods

    KAUST Repository

    Ketcheson, David I.; Loczi, Lajos; Parsani, Matteo

    2014-01-01

    of internal stability polynomials can be obtained by modifying the implementation details. We provide bounds on the internal error amplification constants for some classes of methods with many stages, including strong stability preserving methods

  14. Effect of thermal treatment on rutin content in selected buckwheat products using calcium as an internal tracer

    Directory of Open Access Journals (Sweden)

    Eliška Krejzová

    2017-01-01

    Full Text Available Reversed-phase high-performance liquid chromatography (RP-HPLC was used for rutin (quercetin-3-rutinoside determination in selected buckwheat products (whole meal flour, broken seeds, seed hulls, herbs and baked cereal breads. The effect of various thermal procedures on content of rutin was evaluated using calcium as an internal tracker to correct changes in mass and composition of the buckwheat products. These factors are very seldom taken into account. The results show non-significant changes in rutin levels obtained in whole meal flour and broken seed samples after thermal treatment up to 150°C. Higher temperature already caused sudden fall in the observed rutin concentrations. The evaporation of some volatile compounds and degradation products can decrease the mass of the samples and formally increase the content of rutin (35.5 ±4.7 mg per 100 g for whole meal flour and 10.2 ±0.4 mg per100 g for broken seeds at 150°C. Serious decrease of rutin contents at elevated temperatures (>150°C can be explained by its degradation (by breaking off the C-C bond in quercetin-3-rutinoside moiety and/or evaporation (24.3 ±1.4 mg per 100 g for whole meal flour and 3.06 ±0.3 mg per100 g for broken seeds at 180°C. In case of baked cereal breads the level of rutin changed in dependence on the ratio between buckwheat and corn flour. Longer time leaching and higher temperature implicate higher rutin content in infusions prepared from buckwheat seed hulls and herbs.

  15. Internal combustion engine and method for control

    Science.gov (United States)

    Brennan, Daniel G

    2013-05-21

    In one exemplary embodiment of the invention an internal combustion engine includes a piston disposed in a cylinder, a valve configured to control flow of air into the cylinder and an actuator coupled to the valve to control a position of the valve. The internal combustion engine also includes a controller coupled to the actuator, wherein the controller is configured to close the valve when an uncontrolled condition for the internal engine is determined.

  16. Propagation of internal errors in explicit Runge–Kutta methods and internal stability of SSP and extrapolation methods

    KAUST Repository

    Ketcheson, David I.; Loczi, Lajos; Parsani, Matteo

    2014-01-01

    of internal stability polynomials can be obtained by modifying the implementation details. We provide bounds on the internal error amplification constants for some classes of methods with many stages, including strong stability preserving methods

  17. Radioisotope tracer applications in industry

    International Nuclear Information System (INIS)

    Rao, S.M.

    1987-01-01

    Radioisotope tracers have many advantages in industrial trouble-shooting and studies on process kinetics. The applications are mainly of two types: one leading to qualitative (Yes or No type) information and the other to quantitative characterisation of flow processes through mass balance considerations and flow models. ''Yes or No'' type methods are mainly used for leakage and blockage locations in pipelines and in other industrial systems and also for location of water seepage zones in oil wells. Flow measurements in pipelines and mercury inventory in electrolytic cells are good examples of tracer methods using the mass balance approach. Axial dispersion model and Tanks-in-Series model are the two basic flow models commonly used with tracer methods for the characterisation of kinetic processes. Examples include studies on flow processes in sugar crystallisers as well as in a precalcinator in a cement plant. (author). 18 figs

  18. INTERNATIONAL PAYMENT METHODS AND TECHNIQUES FROM THE ACCOUNTING PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    MAGDALENA MIHAI

    2013-08-01

    Full Text Available The starting point in our study regarding the international payment methods and techniques is the ideaaccording to which the international settlements are based on uniform fundament rules set by the states that takepart in international trade. Since the world economy and especially the international trade have evolved, theserules are changed and adapted to international trade necessities resulted from international trade. Theimportance of the topic consists in the idea that companies in our country are increasingly adopting,international trade activities. For this reason, in this paper we will conceptually determine the methods forinternational settlement, as well as present the accounting consequences regarding the international tradeactivity settlement. It is necessary to study the accounting implications that regard the management of collectionand payment activities in the intra- and extra-community trade since international trade as well as Europeanand international influences in national accounting regulations have been developed in our country.

  19. OPERATIONAL RISK IN INTERNATIONAL BUSINESS: TAXONOMY AND ASSESSMENT METHODS

    Directory of Open Access Journals (Sweden)

    Marinoiu Ana Maria

    2009-05-01

    Full Text Available The paper aims at presenting the classifications and the assessment methods for operational risk according to international regulations (ie. Basel 2, in the context of its importance as a managerial tool for international business. Considering the growin

  20. Gas exchange rates measured using a dual-tracer (SF6 and3he) method in the coastal waters of Korea

    Science.gov (United States)

    Lee, Hyun-Woo; Lee, Kitack; Kaown, Duk-In

    2008-03-01

    Over a period of 5 days between August 12 and 17, 2005, we performed a gas exchange experiment using the dual tracer method in a tidal coastal ocean located off the southern coast of Korea. The gas exchange rate was determined from temporal changes in the ratio of3He to SF6 measured daily in the surface mixed layer. The measured gas exchange rate ( k CO 2), normalized to a Schmidt number of 600 for CO2 in fresh water at 20°C, was approximately 5.0 cm h-1 at a mean wind speed of 3.9 m s-1 during the study period. This value is significantly less than those obtained from floating chamber-based experiments performed previously in estuarine environments, but is similar in magnitude to values obtained using the dual tracer method in river and tidal coastal waters and values predicted on the basis of the relationship between the gas exchange rate and wind speed (Wanninkhof 1992), which is generally applicable to the open ocean. Our result is also consistent with the relationship of Raymond and Cole (2001), which was derived from experiments carried out in estuarine environments using222Rn and chlorofluorocarbons along with measurements undertaken in the Hudson River, Canada, using SF6 and3He. Our results indicate that tidal action in a microtidal region did not discernibly enhance the measured k CO 2 value.

  1. Tracer a application in marine outfall studies

    International Nuclear Information System (INIS)

    Genders, S.

    1979-01-01

    The applicability of radioactive and fluorescent tracers for field studies to predict or investigate waste water transport and dispersion from marine outfalls is evaluated. The application of either instantaneous or continuous tracer release, 'in situ' detection of tracers and data processing are considered. The necessity of a combined use of tracer techniques and conventional hydrographic methods for a statistical prediction of transport and dillution of waste water are pointed out. A procedure to determine an outlet distance from the coast, which satisfy bathing water criteria is outlined. (M.A.) [pt

  2. Transient methods to characterize flows and mass transfer in a packed column by tracers; Methodes transitoires de caracterisation des ecoulements et du transfert de masse dans une colonne a garnissage a l'aide de traceurs

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, S.

    1998-06-11

    The aim of this study is to propose a packed column characterization method in the form of phases flows and mass transfer model, in which the parameters are estimated by transient technique. After a bibliographic study a model is performed and validated. It allows efficiency and precision in the parameters choice. Two tracer techniques have been implemented: they show interesting possibilities of flow diagnosis. (A.L.B.)

  3. Certification of flow measurement methods and calibration of flowmeters in oil and gas industry using radioactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, L. E. E.; Kenup, H.O. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Nóbrega, Armi W.; Gonçalves, E.R.; Dualibi Filho, J.C.; Malheiro, R.L., E-mail: brandaos@ien.gov.br, E-mail: atomum@atomum.com.br [ATOMUM Serviços Tecnológicos Ltda, Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Oil and gas, mineral and water supply plants are the typical example of industrial facilities where they need accuracy in fluid flow measurement's procedures. In these installations, large quantities of materials are moving daily inside pipes, and one of the major problems of these industries is the safety of operations in transport of these materials. In order to monitor the transference processes many flowmeters are installed in the pipes to measure constantly the condition of the transported fluid. These flowmeters must be periodically calibrated, and one of the problems in this standardization is that these instruments need to be removed from the pipelines where they are operating and transported to the accredited laboratories to be calibrated. To remove a flowmeter from a pipe is not an easy operation, and in most of the cases, it is a very expensive operation, and in addition, any changes in the pipeline configuration can provoke leaks and when a leak occurs, it is impossible to operate the whole line and provokes accidents. Radiotracer technique is noninvasive fluid flow measure and using proper radiotracers is possible to measure organic, aqueous and gaseous flows without any disturbance in the normal operation of the pipeline. In this work, we present the ATOMUM{sub T}RACER, a software used to determine geometrical and technical procedures to calculate the Residence Time Curves using radiotracer techniques to accurately measure flow of fluids in pipelines with uncertainties around 0.7%. (author)

  4. Quadratic tracer dynamical models tobacco growth

    International Nuclear Information System (INIS)

    Qiang Jiyi; Hua Cuncai; Wang Shaohua

    2011-01-01

    In order to study the non-uniformly transferring process of some tracer dosages, we assume that the absorption of some tracer by tobacco is a quadratic function of the tracer quantity of the tracer in the case of fast absorption, whereas the exclusion of the tracer from tobacco is a linear function of the tracer quantity in the case of slow exclusion, after the tracer is introduced into tobacco once at zero time. A single-compartment quadratic dynamical model of Logistic type is established for the leaves of tobacco. Then, a two-compartment quadratic dynamical model is established for leaves and calms of the tobacco. Qualitative analysis of the models shows that the tracer applied to the leaves of the tobacco is excluded finally; however, the tracer stays at the tobacco for finite time. Two methods are also given for computing the parameters in the models. Finally, the results of the models are verified by the 32 P experiment for the absorption of tobacco. (authors)

  5. Selection of tracers for oil and gas evaluation

    International Nuclear Information System (INIS)

    Bjoernstad, T.

    1991-08-01

    The importance of tracer tests in reservoir descriptions is increasingly acknowledged by reservoir engineers as a method to obtain valuable dynamic information from the reservoir. The report describes the ''state-of-the art'' on tracer technology for interwell investigations. Experiences gained from a number of reported field tracer tests are reviewed, and results from detailed laboratory investigations on the static and dynamic behavior of various tracer molecules are discussed. A critical evaluation of the applicability of the various identified tracers is provided. Present and future trends in the development of tracer technology for reservoir description are sketched. 64 refs., 12 figs., 2 tabs

  6. Role of tracer methods in hydrology as a source of physical information. Basic concepts and definitions. Time relationship in dynamic systems

    International Nuclear Information System (INIS)

    Nir, A.

    1986-01-01

    The paper provides a general review on the systems theory approach for the tracer methodology, indicating also the relations of the system theory to other available approaches such as deterministic mechanism description and stochastic approaches. Methodology and formulations of systems approach as applied to tracer use in steady-state cases are discussed. Extension of the systems approach for tracer use in non-steady-state cases and input-output relationships for time varying systems are also given. (author)

  7. Simulation and interpretation of inter-well tracer tests

    Directory of Open Access Journals (Sweden)

    Dugstad Øyvind

    2013-05-01

    Full Text Available In inter-well tracer tests (IWTT, chemical compounds or radioactive isotopes are used to label injection water and gas to establish well connections and fluid patterns in petroleum reservoirs. Tracer simulation is an invaluable tool to ease the interpretation of IWTT results and is also required for assisted history matching application of tracer data. In this paper we present a new simulation technique to analyse and interpret tracer results. Laboratory results are used to establish and test formulations of the tracer conservation equations, and the technique is used to provide simulated tracer responses that are compared with observed tracer data from an extensive tracer program. The implemented tracer simulation methodology use a fast post-processing of previously simulated reservoir simulation runs. This provides a fast, flexible and powerful method for analysing gas tracer behaviour in reservoirs. We show that simulation time for tracers can be reduced by factor 100 compared to solving the tracer flow equations simultaneously with the reservoir fluid flow equations. The post-processing technique, combined with a flexible built-in local tracer-grid refinement is exploited to reduce numerical smearing, particularly severe for narrow tracer pulses.

  8. Direct methods for determining internal contamination

    International Nuclear Information System (INIS)

    Melandri, C.

    1985-01-01

    The direct methods of investigation on body content of radionuclides emitting gamma rays with energies higher than 100 KeV are described. After a short review of the earlier methods, the main technical charateristics of the present used whole body counters and counting geometries are described together with the calibration methods. Qualitative and quantitative data interpretation are also briefly discussed. The minimum detectable activity and the Derived Investigation Levels at different times from the intake both by ingestion or by inhalation as aerosol are finally compared for some radionuclides of great importance in the health physic survey

  9. A New Method to Calculate Internal Rate of Return

    Directory of Open Access Journals (Sweden)

    azadeh zandi

    2015-09-01

    Full Text Available A number of methods have been developed to choose the best capital investment projects such as net present value, internal rate of return and etc. Internal rate of return method is probably the most popular method among managers and investors. But despite the popularity there are serious drawbacks and limitations in this method. After decades of efforts made by economists and experts to improve the method and its shortcomings, Magni in 2010 has revealed a new approach that can solves the most of internal rate of return method problems. This paper present a new method which is originated from Magni’s approach but has much more simple calculations and can resolve all the drawbacks of internal rate of return method.

  10. Count rate balance method of measuring sediment transport of sand beds by radioactive tracers; Methode du bilan des taux de comptage d'indicateurs radioactifs pour la determination du debit de charriage des lits sableux

    Energy Technology Data Exchange (ETDEWEB)

    Sauzay, G [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1967-11-01

    Radioactive tracers are applied to the direct measurement of the sediment transport rate of sand beds. The theoretical measurement formula is derived: the variation of the count rate balance is inverse of that of the transport thickness. Simultaneously the representativeness of the tracer is critically studied. The minimum quantity of tracer which has to be injected in order to obtain a correct statistical definition of count rate given by a low number of grains 'seen' by the detector is then studied. A field experiment was made and has let to study the technological conditions for applying this method: only the treatment of results is new, the experiment itself is carried out with conventional techniques applied with great care. (author) [French] Les indicateurs radioactifs sont appliques a la mesure directe du debit de charriage des lits sableux. On etablit la formule theorique de mesure: le bilan des taux de comptage varie en sens inverse de l'epaisseur de charriage. Parallelement on fait une etude critique de la representativite de l'indicateur, puis on determine la quantite minimale de traceur qu'il faut immerger pour que les taux de comptage fournis pour un faible nombre de grains 'vus' par le detecteur aient une definition statistique correcte. Une experience de terrain a permis d'etudier les conditions technologiques de cette methode: seul le depouillement des resultats est nouveau. L'experimentation in-situ se fait suivant les procedes classiques avec un tres grand soin. (auteur)

  11. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  12. Radon as geological tracer

    International Nuclear Information System (INIS)

    Lacerda, T.; Anjos, R.M.; Silva, A.A.R. da; Yoshimura, E.M.

    2012-01-01

    Full text: This work presents measurements of 222 Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of 40 K, 232 Th and 23 '8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using 222 Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m -3 recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  13. Axial mixing for both dispersed and continuous phases in pulsed perforated-plate extraction column by tracer co-injection method

    International Nuclear Information System (INIS)

    Ikeda, Hidematsu; Suzuki, Atsuyuki.

    1991-01-01

    The effects of operation mode and perforated-plate type on axial mixing of mixer-settler region in both dispersed and continuous phases were studied for a 5 cm I.D. pulsed perforated-plate extraction column of pulser-feeder type. The axial mixing coefficient was simultaneously measured to both phases by using the 'dynamic tracer co-injection method' proposed by the authors. The characteristics of both phases are observed obviously. Relatively to what it was in the continuous phase, the dispersed phase had short reaching time and long retardation time. The superficial axial mixing coefficient for dispersed phase becomes smaller than for the continuous phase. And experimental results showed that a backflow took place only in dispersed phase at a test section of 50 cm in axial length. The values of backflow ratio are observed from 0.5 to 1.8% of the dispersed net flow. (author)

  14. Beach sediments drift study by means of radioactive tracers; L'etude du transport littoral par la methode des traceurs radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The present state of the sediments drift studies by means of radioactive tracers is exposed. Various processes of labelling, immersion and detection, used in France and other countries, are reviewed. A more extended analysis of some aspects of the problem by the same authors can be found in 'La Houille Blanche', number 3, may-june 1959 (Rapport C.E.A. number 1269). (author) [French] L'etude du transport littoral des sediments et galets par la methode des traceurs radioactifs est en plein developpement. Le present rapport precise l'etat actuel de la question. Les techniques de marquage, d'immersion et de detection utilisees en France et a l'etranger sont decrites; une analyse plus detaillee de certains aspects de la question est presentee par les memes auteurs dans 'La Houille Blanche', numero 3, mai-juin 1959 (Rapport C.E.A. numero 1269). (auteur)

  15. Seeing the sink beneath the source: an improved stable isotope tracer method for measuring highly variable gross fluxes of methyl halides

    Science.gov (United States)

    Rhew, R. C.

    2011-12-01

    Measuring methyl bromide (CH3Br) and methyl chloride (CH3Cl) fluxes in terrestrial ecosystems is complicated by the presence of simultaneous production (typically associated with plants and/or fungi) and consumption (typically associated with soils). Thus, specific sites within an ecosystem can act as either a net source or net sink, depending on season, soil conditions, or vegetative cover. To interpret the highly variable net fluxes found in many of these ecosystems, a stable isotope tracer technique has been developed to measure gross fluxes of CH3Br and CH3Cl. This method entails adding small amounts of 13CH3Br and 13CH3Cl to an incubation chamber, monitoring the headspace concentration changes of both 13C and 13C isotopologues, and applying a box model to simultaneously solve for gross production and consumption. Over the last decade, this technique has been successfully applied to laboratory soil incubations and field studies from a variety of ecosystems, including boreal forest, annual grasslands, shortgrass steppe, oak-savanna woodland, and Arctic tundra. These studies demonstrate that gross uptake rates are strongly affected by soil moisture within ecosystems but are on average much lower than previously estimated, and that gross production rates are highly dependent on plant species enclosed, with minor production within the soils as well. Measuring gross uptake rates is more challenging in ecosystems with large net emissions of methyl halides, such as coastal salt marshes, rice fields and certain grassland sites. Using the tallgrass prairie of Kansas as a case study, four slightly different models to calculate gross fluxes are compared. These models are largely in agreement except at sites with large emissions (i.e., sites with Amorpha shrubs), where one of the models most robustly quantifies gross consumption. This improved stable isotope tracer method is used to track the separate responses of gross production and gross consumption of methyl halides

  16. Internal Error Propagation in Explicit Runge--Kutta Methods

    KAUST Repository

    Ketcheson, David I.

    2014-09-11

    In practical computation with Runge--Kutta methods, the stage equations are not satisfied exactly, due to roundoff errors, algebraic solver errors, and so forth. We show by example that propagation of such errors within a single step can have catastrophic effects for otherwise practical and well-known methods. We perform a general analysis of internal error propagation, emphasizing that it depends significantly on how the method is implemented. We show that for a fixed method, essentially any set of internal stability polynomials can be obtained by modifying the implementation details. We provide bounds on the internal error amplification constants for some classes of methods with many stages, including strong stability preserving methods and extrapolation methods. These results are used to prove error bounds in the presence of roundoff or other internal errors.

  17. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  18. Experimental quantification of solute transport through the vadose zone under dynamic boundary conditions with dye tracers and optical methods.

    Science.gov (United States)

    Cremer, Clemens; Neuweiler, Insa

    2017-04-01

    Knowledge of subsurface solute transport processes is vital to investigate e.g. groundwater contamination, nutrient uptake by plant roots and to implement remediation strategies. Beside field measurements and numerical simulations, physical laboratory experiments represent a way to establish process understanding and furthermore validate numerical schemes. Atmospheric forcings, such as erratically varying infiltration and evaporation cycles, subject the shallow subsurface to local and temporal variations in water content and associated hydraulic conductivity of the prevailing porous media. Those variations in material properties can cause flow paths to differ between upward and downward flow periods. Thereby, the unsaturated subsurface presents a highly complicated, dynamic system. Following an extensive systematical numerical investigation of flow and transport through bimodal, unsaturated porous media under dynamic boundary conditions (Cremer et al., 2016), we conduct physical laboratory experiments in a 22 cm x 8 cm x 1 cm flow cell where we introduce structural heterogeneity in the form sharp material interfaces between different porous media. In all experiments, a constant pressure head is implemented at the lower boundary, while cyclic infiltration-evaporation phases are applied at the soil surface. As a reference case a stationary infiltration with a rate corresponding to the cycle-averaged infiltration rate is applied. By initial application of dye tracers, solute transport within the domain is visualized such that transport paths and redistribution processes can be observed in a qualitative manner. Solute leaching is quantified at the bottom outlet, where breakthrough curves are obtained via spectroscopy. Liquid and vapor flow in and out of the domain is obtained from multiple balances. Thereby, the interplay of material structural heterogeneity and alternating flow (transport) directions and flow (transport) paths is investigated. Results show lateral

  19. TRANSFER PRICES: MECHANISMS, METHODS AND INTERNATIONAL APPROACHES

    Directory of Open Access Journals (Sweden)

    Pop Cosmina

    2008-05-01

    Full Text Available Transfer prices are considered the prices paid for the goods or services in a cross-border transaction between affiliates companies, often significant reduced or increased in order to avoid the higher imposing rates from one jurisdiction. Presently, over 60% of cross-border transfers are represented by intra-group transfers. The paper presents the variety of methods and mechanisms used by the companies to transfer the funds from one tax jurisdiction to another in order to avoid over taxation.

  20. Propagation of internal errors in explicit Runge–Kutta methods and internal stability of SSP and extrapolation methods

    KAUST Repository

    Ketcheson, David I.

    2014-04-11

    In practical computation with Runge--Kutta methods, the stage equations are not satisfied exactly, due to roundoff errors, algebraic solver errors, and so forth. We show by example that propagation of such errors within a single step can have catastrophic effects for otherwise practical and well-known methods. We perform a general analysis of internal error propagation, emphasizing that it depends significantly on how the method is implemented. We show that for a fixed method, essentially any set of internal stability polynomials can be obtained by modifying the implementation details. We provide bounds on the internal error amplification constants for some classes of methods with many stages, including strong stability preserving methods and extrapolation methods. These results are used to prove error bounds in the presence of roundoff or other internal errors.

  1. Development of a method for in situ measurement of denitrification in aquifers using 15N tracer tests and membrane inlet mass spectrometry

    Science.gov (United States)

    Eschenbach, W.; Well, R.; Flessa, H.; Walther, W.; Duijnisveld, W. H. M.

    2009-04-01

    In NO3- contaminated aquifers containing reduced compounds like organic carbon or sulfides, denitrification is an intense process. Its characterization is of interest because NO3- consump-tion improves water quality and N2O production can cause emission of this greenhouse gas to the atmosphere. Spatial distribution of NO3- and N2 produced by denitrification in groundwa-ter (excess N2) reflects the NO3- input as well as cumulative denitrification during aquifer pas-sage. Reaction progress (RP) at a given location, i.e. the relative consumption by denitrifica-tion of the NO3- that had been leached to the aquifers, characterizes the stage of the denitrifi-cation process. RP can be derived from the ratio between accumulated gaseous denitrification products and initial NO3- concentrations. The amount and spatial distribution of reduced com-pounds within denitrifying aquifers is not well known. Recent findings from parallel investi-gations on in situ denitrification and reactive compounds suggests that single-well 15N tracer tests might be suitable to characterize the stock of reduced compounds in aquifers (Konrad 2007). The overall objective of our studies is measure the spatial dynamics of denitrification within two sandy aquifers in northern Germany. This includes measurement of the actually occurring denitrification process. Moreover we want to determine the long-term denitrification potential which is governed by the stock of reactive material. Here we present a new approach for in situ-measurement of denitrification at monitoring wells using a combination of 15N-tracer push-pull experiments with in situ analysis of 15N-labled N2 and N2O using membrane inlet mass spectrometry (MIMS). We will present first results from a laboratory test with aquifer mesocosms using the MIMS method. In this test we supplemented aquifer material of two depths (2 and 7 m below surface) of a drinking water catchment in Northwest Germany with K15NO3 solution. After tracer application we

  2. A Rapid ELISA Method for 17, 20b-dihydroxy-4-pregenen-3-one (17,20bP Hormone Using Acetylcholinesterase Enzyme as Tracer

    Directory of Open Access Journals (Sweden)

    M Ebrahimi

    2004-06-01

    Full Text Available Background: During the past 15 years Enzyme Linked ImmunoSorbent Assay (ELISA has been described as an alternative to radioimmunoassay for steroid detection. In addition to gonads, sperm itself is capable of producing reduced progesterone metabolites. In this study we introduced a method to extend the applicability of previous measures by describing a general preparation procedure for the enzyme label which is applicable to any steroid hormone. Methods: A simple and rapid Enzyme Linked Immunosorbant Assay (ELISA is described and validated for 17,20β- dihydroxy-4-pregnen-3-one (17,20βP. A general procedure for preparation of the acetylcholinesterase labelled steroid is described which is applicable to any steroid. Results: Use of acetylcholinesterase tracer increased the sensitivity of assay so that reliable measurements of each steroid could be achieved with only 10 µl of plasma. ELISA was applied to measure of 17,20βP steroid production by sperm of trout which has sufficient amount of potent and active 20βHSD enzyme to convert 17α-hydroxy-4-pregnen-3-one (17αP substrate to 17,20βP product. The results showed that a clear shift in 17,20βP production was found with increase in substrate concentration in all in vitro incubations. Conclusion: ELISA method presented in this study has greater sensitivity and accuracy compared to previously described method that uses radiolabelled substances. Keywords: Immunoassay, ELISA, Steroids, Hormone, Assay

  3. A novel method of generating and remembering international morse codes

    Digital Repository Service at National Institute of Oceanography (India)

    Charyulu, R.J.K.

    untethered communications have been advanced, despite as S.O.S International Morse Code will be at rescue as an emergency tool, when all other modes fail The details of hte method and actual codes have been enumerated....

  4. Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-08-01

    This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

  5. Tracer studies on the effect of different methods of phosphorus application on fertilizer P uptake by Sunnhemp (Crotolaria juncea L.)

    International Nuclear Information System (INIS)

    Chaudhury, J.; Ray, P.K.

    1994-01-01

    The relative efficacy of seven methods of phosphorus application on dry matter yield, and fertilizer phosphorus uptake and its utilization by Sunnhemp (var. K-12 yellow) was studied under field conditions using 32 P tagged superphosphate (SSP). Fertilizer was least utilized by the traditional method of application of fertilizer i.e. broadcasting, whereas placement below the seed was significantly superior to all other methods in relation to dry matter yield, total and fertilizer P uptake by Sunnhemp. The per cent utilization of fertilizer P added and per cent Pdff followed the similar pattern as that of the dry matter yield. (author). 7 refs., 1 tab

  6. Constraints on primary and secondary particulate carbon sources using chemical tracer and 14C methods during CalNex-Bakersfield

    Data.gov (United States)

    U.S. Environmental Protection Agency — The present study investigates primary and secondary sources of organic carbon for Bakersfield, CA, USA as part of the 2010 CalNex study. The method used here...

  7. A simple method for the determination of the specific activity of 125I-tracer used in radioimmunoassay

    International Nuclear Information System (INIS)

    Bhupal, V.; Mani, R.S.

    1986-01-01

    The specific activity of the 125 I-thyroxin used in thyroxin radioimmunoassay (RIA) was determined by a simple method involving combination of RIA and displacement analysis. It was compared with the value obtained by the conventional method based on radioiodination data. It is indicated that even for a non-protein hormone like thyroxin the specific activity of 125 I-thyroxin derived from iodination data is not reliable. The specific activites obtained by displacement analysis were consistent with the experimental findings. (author)

  8. Tracer attenuation in groundwater

    Science.gov (United States)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  9. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  10. Application of stable isotope tracer methods to studies of amino acid, protein, and energy metabolism in malnourished populations of developing countries. Report of an IAEA consultants' meeting held in Vienna, Austria, 14-16 December 1992

    International Nuclear Information System (INIS)

    1993-01-01

    A Consultants' Meeting convened by the IAEA in December 1992, made recommendations on the organization of a Co-ordinated Research Programme (CRP) using stable isotopic techniques for international comparative studies of amino acid, protein, and energy metabolism in chronically undernourished people. The CRP will use recent developments in stable isotope tracer techniques ( 13 C and 15 N) to assess the impact of infection in undernourished people on the kinetics of protein breakdown, protein synthesis, amino acid metabolism, and on the synthetic rates of selected plasma proteins. Studies will be conducted in developing countries, particularly in young children. The programme goals are to (i) elaborate methods and model protocols which can be implemented in developing countries to investigate the impact on protein metabolism of infection superimposed on chronic undernutrition; (ii) test they hypothesis that dietary requirements for protein and amino acids are related to the place of nutrition and are altered substantially when infection is superimposed on chronic undernutrition. When feasible, the primary focus on protein/amino acid metabolism will be extended to assessments of protein/energy interactions when H 2 18 O becomes more readily available and/or at research sites with indirect calorimetry equipment. The data generated should be appropriate as a basis for reevaluating amino acid/protein requirements in these populations. Refs

  11. Optimizing the mercury mass measurement in industrial electrolytic cells by the radio-tracer method at ININ; Optimizacion de la medicion de masa de mercurio en celdas electroliticas industriales por el metodo de radiotrazado en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valle R, J.; Angeles C, A., E-mail: Ing.valle.r@hotmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    One method used in the production of chlorine and sodium is the use of electrolytic cells for the separation of chlorine and sodium from the brine; the industries apply very intense electromagnetic fields in this process. The electrolytic cells use mercury as electrode. In a chlorine production plant inventories are determined by total amount of mercury in the plant annually, since mercury losses are large and a very important parameter is to control the mass of mercury for it is necessary to measure with great precision the losses made. There are several methods to determine the mass of mercury ranging from take samples and weigh, but this involves continuous interruption of the process creating downtimes which in turn represent economic losses giving a result delimiting productivity for the industrial sector. An alternative and attractive method is to use a radioactive tracer whose principle has a similar behavior to study objective. The inert mercury has to be neutron activated in a nuclear reactor to having the characteristics of a tracer; the result makes one of the isotopes of mercury. The tracer is transported taking into account the recommendations of the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexico), then it is injected into the electrolytic cells mixing with the mercury in the system. By a relative radioactivity measurement and one sample by gamma spectrometry per interest cell, the mass of mercury without stopping the process is obtained. For optimal use of radio-tracer method must be taken into account as important features: irradiation time of mercury, counting conditions, vial geometry, sample volume, sample cells, mixing time and half-life of the tracer. (Author)

  12. Tracers vs. trajectories in a coastal region

    Science.gov (United States)

    Engqvist, A.; Döös, K.

    2008-12-01

    Two different methods of estimating the water exchange through a Baltic coastal region have been used, consisting of particle trajectories and passive tracers. Water is traced from and to a small discharge region near the coast. The discharge material in this region is treated as zero dimensional particles or tracers with neutral buoyancy. The real discharge material could be a leakage of radio-nuclides through the sea floor from an underground repository of nuclear waste. Water exchange rates between the discharge region and the model domain are estimated using both forward and backward trajectories as well as passive tracers. The Lagrangian trajectories can account for the time evolution of the water exchange while the tracers give one average age per model grid box. Water exchange times such as residence time, age and transient times have been calculated with trajectories but only the average age (AvA) for tracers. The trajectory calculations provide a more detailed time evolution than the tracers. On the other hand the tracers are integrated "on-line" simultaneously in the sea circulation model with the same time step while the Lagrangian trajectories are integrated "off-line" from the stored model velocities with its inherent temporal resolution, presently one hour. The sub-grid turbulence is parameterised as a Laplacian diffusion for the passive tracers and with an extra stochastic velocity for trajectories. The importance of the parameterised sub-grid turbulence for the trajectories is estimated to give an extra diffusion of the same order as the Laplacian diffusion by comparing the Lagrangian dispersions with and without parameterisation. The results of the different methods are similar but depend on the chosen diffusivity coefficient with a slightly higher correlation between trajectories and tracers when integrated with a lower diffusivity coefficient.

  13. A solution of the dispersion-convection equation of radial tracer transportation by the finite element variational method

    International Nuclear Information System (INIS)

    Hubert, J.

    1979-01-01

    The variational finite element method (of the Rayleigh-Ritz type) has been applied to solve the standard diffusion-convection equation of radial flow in a dispersive medium. It was shown that the imposing of the boundary condition ΔC/Δx = 0 (=null concentration gradient) introduced great errors in computation results. To remedy it this condition was imposed at the free end of the artifical domain. Its other end joined to the downstream boundary of the investigated domain. The results of calculations compared with the known analytical solutions of the parallel flow show their good accuracy. The method was used to discuss the applicability of the approximate analytical solutions of the radial flow. (author)

  14. Method of characteristics - Based sensitivity calculations for international PWR benchmark

    International Nuclear Information System (INIS)

    Suslov, I. R.; Tormyshev, I. V.; Komlev, O. G.

    2013-01-01

    Method to calculate sensitivity of fractional-linear neutron flux functionals to transport equation coefficients is proposed. Implementation of the method on the basis of MOC code MCCG3D is developed. Sensitivity calculations for fission intensity for international PWR benchmark are performed. (authors)

  15. Using Tracer Technology to Characterize Contaminated Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Maresca, Joseph, W., Jr., Ph.D.; Bratton, Wesley, L., Ph.D., P.E.; Dickerson, Wilhelmina; Hales, Rochelle

    2005-12-30

    The Pipeline Characterization Using Tracers (PCUT) technique uses conservative and partitioning, reactive or other interactive tracers to remotely determine the amount of contaminant within a run of piping or ductwork. The PCUT system was motivated by a method that has been successfully used to characterize subsurface soil contaminants and is similar in operation to that of a gas chromatography column. By injecting a ?slug? of both conservative and partitioning tracers at one end (or section) of the piping and measuring the time history of the concentration of the tracers at the other end (or another section) of the pipe, the presence, location, and amount of contaminant within the pipe or duct can be determined. The tracers are transported along the pipe or duct by a gas flow field, typically air or nitrogen, which has a velocity that is slow enough so that the partitioning tracer has time to interact with the contaminant before the tracer slug completely passes over the contaminate region. PCUT not only identifies the presence of contamination, it also can locate the contamination along the pipeline and quantify the amount of residual. PCUT can be used in support of deactivation and decommissioning (D&D) of piping and ducts that may have been contaminated with hazardous chemicals such as chlorinated solvents, petroleum products, radioactive materials, or heavy metals, such as mercury.

  16. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  17. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  18. Evaluation of internal noise methods for Hotelling observer models

    International Nuclear Information System (INIS)

    Zhang Yani; Pham, Binh T.; Eckstein, Miguel P.

    2007-01-01

    The inclusion of internal noise in model observers is a common method to allow for quantitative comparisons between human and model observer performance in visual detection tasks. In this article, we studied two different strategies for inserting internal noise into Hotelling model observers. In the first strategy, internal noise was added to the output of individual channels: (a) Independent nonuniform channel noise, (b) independent uniform channel noise. In the second strategy, internal noise was added to the decision variable arising from the combination of channel responses. The standard deviation of the zero mean internal noise was either constant or proportional to: (a) the decision variable's standard deviation due to the external noise, (b) the decision variable's variance caused by the external noise, (c) the decision variable magnitude on a trial to trial basis. We tested three model observers: square window Hotelling observer (HO), channelized Hotelling observer (CHO), and Laguerre-Gauss Hotelling observer (LGHO) using a four alternative forced choice (4AFC) signal known exactly but variable task with a simulated signal embedded in real x-ray coronary angiogram backgrounds. The results showed that the internal noise method that led to the best prediction of human performance differed across the studied model observers. The CHO model best predicted human observer performance with the channel internal noise. The HO and LGHO best predicted human observer performance with the decision variable internal noise. The present results might guide researchers with the choice of methods to include internal noise into Hotelling model observers when evaluating and optimizing medical image quality

  19. Determination of the separation efficiencies of a single-stage cryogenic distillation setup to remove krypton out of xenon by using a (83m)Kr tracer method.

    Science.gov (United States)

    Rosendahl, S; Brown, E; Cristescu, I; Fieguth, A; Huhmann, C; Lebeda, O; Murra, M; Weinheimer, C

    2015-11-01

    The separation of krypton and xenon is of particular importance for the field of direct dark matter search with liquid xenon detectors. The intrinsic contamination of the xenon with radioactive (85)Kr makes a significant background for these kinds of low count-rate experiments and has to be removed beforehand. This can be achieved by cryogenic distillation, a technique widely used in industry, using the different vapor pressures of krypton and xenon. In this paper, we present an investigation on the separation performance of a single stage distillation system using a radioactive (83m)Kr-tracer method. The separation characteristics under different operation conditions are determined for very low concentrations of krypton in xenon at the level of (83m)Kr/Xe = 1.9 ⋅ 10(-15), demonstrating, that cryogenic distillation in this regime is working. The observed separation is in agreement with the expectation from the different volatilities of krypton and xenon. This cryogenic distillation station is the first step on the way to a multi-stage cryogenic distillation column for the next generation of direct dark matter experiment XENON1T.

  20. Internal dosimetry hazard and risk assessments: methods and applications

    International Nuclear Information System (INIS)

    Roberts, G.A.

    2006-01-01

    Routine internal dose exposures are typically (in the UK nuclear industry) less than external dose exposures: however, the costs of internal dosimetry monitoring programmes can be significantly greater than those for external dosimetry. For this reason decisions on when to apply routine monitoring programmes, and the nature of these programmes, can be more critical than for external dosimetry programmes. This paper describes various methods for performing hazard and risk assessments which are being developed by RWE NUKEM Limited Approved Dosimetry Services to provide an indication when routine internal dosimetry monitoring should be considered. (author)

  1. A study of effect of fertilizer application methods on uptake of N and P by rape using tracer technique

    International Nuclear Information System (INIS)

    Zhang Qinzheng

    1995-01-01

    Pot experiments were conducted to investigate the effect of application method of urea and placement of phosphates on uptake and utilization of N and P from fertilizer by rape. 15 N-urea was applied at bolting and flowering stages by surface broadcast (B), 1% solution (J) and surface broadcast followed by watering (BJ). Recoveries of applied N from mature plants were 24.44%, 32.15% and 27.38% respectively, and utilization of urea-N by seeds were 13.11%, 21.77% and 15.94% respectively. 32 P-Ca(H 2 PO 4 ) 2 was applied at seedling stage and the labelled fertilizer was placed in band with 2 cm and 4 cm depth and hole with 4 cm depth, respectively. 32 P absorbed by plants 83 days after labelling were 7.04%, 8.24% and 6.56 respectively

  2. Radioimmunoassay for human myoglobin: methods and results in patients with skeletal muscle or myocardial disorders. [/sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Miyoshi, K.; Saito, S.; Kawai, H.; Kondo, A.; Iwasa, M.; Hayashi, T.; Yagita, M.

    1978-09-01

    A sensitive and specific radioimmunoassay has been developed for the measurement of serum Mb. Immunization of rabbit with human Mb yielded anti-Mb antibody which was purified by affinity chromatography. Human hemoglobin, CK, and the component of serum per se did not appear to cross-react with the antibody. Mb was radiolabeled by the chloramine T method. The radioimmunoassay method could detect as little as 0.3 ng of Mb and was not affected by hemolysis. Information is also given on precision, recovery, and specimen preservation. Mb levels could be detected in all of 120 normal adults, and the values ranged between 1 and 28 ng/ml (mean, 13.1 +- 6.1). No sex difference was observed. Levels were markedly elevated in all the patients with progressive muscular dystrophy, especially in the Duchenne type at the level of 40 to 1700 ng/ml. It was also noticed that about 70% of female gene carriers of Duchenne type had a slightly increased Mb level. An elevated serum Mb was also noted in polymyositis. In every case of acute myocardial infarction, serum Mb levels were increased, peak values ranging from 175 to 4400 ng/ml and averaging 1162 +- 287.9 Mb levels were elevated faster and peaked earlier (within 6 to 12 hr after the attack) than serum CK activity and returned to nearly normal range within 3 to 4 days. The increase in serum Mb was also noticed in shock and surgery. These data indicate that radioimmunoassay of Mb is a useful test for judging the myolytic state of myogenic myopathies and for early detection of myocardial infarction.

  3. Tracer techniques in food industry

    International Nuclear Information System (INIS)

    Pertsovskij, E.S.; Sakharov, Eh.V.; Dolinin, V.A.

    1980-01-01

    The appicability of radioactive tracer techniques to process control in food industry are considered. Investigations in the field of food industry carried out using the above method are classified. The 1 class included investigations with preliminary preparation of a radioactive indicator and its following introduction in the system studied. The 2 class includes investigations based on the introduction in the system studied of a non-active indicator which is activated in a neutron flux being in samples selected in or after the process investigated. The 3 class includes studies based on investigations of natural radioactivity of certain nuclides in food stuff. The application of tracer techniques to the above classes of investigations in various fields of food industry and the equipment applied are considered in detail [ru

  4. METHODS IN THE POST-METHODS ERA. REPORT ON AN INTERNATIONAL SURVEY ON LANGUAGE TEACHING METHODS'

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2004-06-01

    Full Text Available Do methods still have a place in 21" century language teaching? To answer this question, an international survey was conducted in the surnmer of 1999. A sample of 800 language teachers world-wide randomly drawn from 17,800 TESOLers were each given a 2-page survey. The return rate was 58.5% with the actual usable data set of448, which was analyzed by using both descriptive and inferential statistics. Among the ten commonly recognized teaching methods surveyed, both the Communicative Language Teaching Approach and an eclectic method seem to have the highest rate in familiarity, preference, and use. But when multiple factors, such as teaching contexts, instructional settings, learners' proficiency levels, class size, teaching experience and educational backgrounds of the teachers, and the status of being a native or nonnative English speaking professional were taken into consideration, various patterns and themes emerged. One interesting finding is that Grammar Translation is still used in EFL contexts, in larger classes, and with learners at low proficiency levels, though the ratio between the actual use of this method and teachers' preference does not match. Based on the results of the survey, a new theoretical framework is proposed to conceptualize language teaching methods in the post-methods era.

  5. Estimation of bias with the single-zone assumption in measurement of residential air exchange using the perfluorocarbon tracer gas method.

    Science.gov (United States)

    Van Ryswyk, K; Wallace, L; Fugler, D; MacNeill, M; Héroux, M È; Gibson, M D; Guernsey, J R; Kindzierski, W; Wheeler, A J

    2015-12-01

    Residential air exchange rates (AERs) are vital in understanding the temporal and spatial drivers of indoor air quality (IAQ). Several methods to quantify AERs have been used in IAQ research, often with the assumption that the home is a single, well-mixed air zone. Since 2005, Health Canada has conducted IAQ studies across Canada in which AERs were measured using the perfluorocarbon tracer (PFT) gas method. Emitters and detectors of a single PFT gas were placed on the main floor to estimate a single-zone AER (AER(1z)). In three of these studies, a second set of emitters and detectors were deployed in the basement or second floor in approximately 10% of homes for a two-zone AER estimate (AER(2z)). In total, 287 daily pairs of AER(2z) and AER(1z) estimates were made from 35 homes across three cities. In 87% of the cases, AER(2z) was higher than AER(1z). Overall, the AER(1z) estimates underestimated AER(2z) by approximately 16% (IQR: 5-32%). This underestimate occurred in all cities and seasons and varied in magnitude seasonally, between homes, and daily, indicating that when measuring residential air exchange using a single PFT gas, the assumption of a single well-mixed air zone very likely results in an under prediction of the AER. The results of this study suggest that the long-standing assumption that a home represents a single well-mixed air zone may result in a substantial negative bias in air exchange estimates. Indoor air quality professionals should take this finding into consideration when developing study designs or making decisions related to the recommendation and installation of residential ventilation systems. © 2014 Her Majesty the Queen in Right of Canada. Indoor Air published by John Wiley & Sons Ltd Reproduced with the permission of the Minister of Health Canada.

  6. Method for temporary shielding of reactor vessel internals

    International Nuclear Information System (INIS)

    Grimm, N.P.; Sejvar, J.

    1991-01-01

    This patent describes a method for shielding stored internals for reactor vessel annealing. It comprises removing nuclear fuel from the reactor vessel containment building; removing and storing upper and lower core internals under water in a refueling canal storage area; assembling a support structure in the refueling canal between the reactor vessel and the stored internals; introducing vertical shielding tanks individually through a hatch in the containment building and positioning each into the support structure; introducing horizontal shielding tanks individually through a hatch in the containment building and positioning each above the stored internals and vertical tanks; draining water from the refueling canal to the level of a flange of the reactor vessel; placing an annealing apparatus in the reactor vessel; pumping the remaining water from the reactor vessel; and annealing the reactor vessel

  7. 22nd International Conference on Domain Decomposition Methods

    CERN Document Server

    Gander, Martin; Halpern, Laurence; Krause, Rolf; Pavarino, Luca

    2016-01-01

    These are the proceedings of the 22nd International Conference on Domain Decomposition Methods, which was held in Lugano, Switzerland. With 172 participants from over 24 countries, this conference continued a long-standing tradition of internationally oriented meetings on Domain Decomposition Methods. The book features a well-balanced mix of established and new topics, such as the manifold theory of Schwarz Methods, Isogeometric Analysis, Discontinuous Galerkin Methods, exploitation of modern HPC architectures, and industrial applications. As the conference program reflects, the growing capabilities in terms of theory and available hardware allow increasingly complex non-linear and multi-physics simulations, confirming the tremendous potential and flexibility of the domain decomposition concept.

  8. Internal quality control of RIA with Tonks error calculation method

    International Nuclear Information System (INIS)

    Chen Xiaodong

    1996-01-01

    According to the methodology feature of RIA, an internal quality control chart with Tonks error calculation method which is suitable for RIA is designed. The quality control chart defines the value of the allowance error with normal reference range. The method has the simplicity of its performance and directly perceived through the senses. Taking the example of determining T 3 and T 4 , the calculation of allowance error, drawing of quality control chart and the analysis of result are introduced

  9. Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method.

    Science.gov (United States)

    Iwanishi, Katsuhiro; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Minato, Kotaro; Iida, Hidehiro

    2009-06-01

    Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with PET with (15)O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating (15)O(2) and C(15)O(2) gases. In this protocol, before the sequential PET scan with (15)O(2) and C(15)O(2) gases ((15)O(2)-C(15)O(2) PET scan), a PET scan with C(15)O should be preceded to obtain CBV image. C(15)O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C(15)O might exist during a (15)O(2)-C(15)O(2) PET scan. As the current DARG method assumes no residual C(15)O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C(15)O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C(15)O radioactivity. In the simulation, normal and ischemic conditions were considered. The (15)O(2) and C(15)O(2) PET count curves with the residual C(15)O PET counts were generated by the arterial input function with the residual C(15)O radioactivity. The amounts of residual C(15)O radioactivity were varied by changing the interval between the C(15)O PET scan and (15)O(2)-C(15)O(2) PET scan, and the absolute inhaled radioactivity of the C(15)O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C(15)O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C(15)O radioactivity. The magnitude of this underestimation depended on the amount of C(15)O radioactivity and the physiological conditions. This underestimation

  10. Exploring Hydrofluorocarbons as Groundwater Age Tracers (Invited)

    Science.gov (United States)

    Haase, K. B.; Busenberg, E.; Plummer, L. N.; Casile, G.; Sanford, W. E.

    2013-12-01

    Groundwater dating tracers are an essential tool for analyzing hydrologic conditions in groundwater systems. Commonly used tracers for dating post-1940's groundwater include sulfur hexafluoride (SF6), chlorofluorocarbons (CFCs), 3H-3He, and other isotopic tracers (85Kr, δ2H and δ18O isotopes, etc.). Each tracer carries a corresponding set of advantages and limitations imposed by field, analytical, and interpretive methods. Increasing the number available tracers is appealing, particularly if they possess inert chemical properties and unique temporal emission histories from other tracers. Atmospherically derived halogenated trace gases continue to hold untapped potential for new tracers, as they are generally inert and their emission histories are well documented. SF5CF3, and CFC-13 were previously shown to have application as dating tracers, though their low mixing ratios and low solubility require large amounts of water to be degassed for their quantification. Two related groups of compounds, hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are hypothesized to be potential age tracers, having similar mixing ratios to the CFCs and relatively high solubility. However, these compounds yield gas chromatography electron capture detector (GC-ECD) responses that are 10-2 -10-5 less than CFC-12, making purge and trap or field stripping GC-ECD approaches impractical. Therefore, in order to use dissolved HCFCs and HFCs as age tracers, different approaches are needed. To solve this problem, we developed an analytical method that uses an atomic emission detector (GC-AED) in place of an ECD to detect fluorinated compounds. In contrast to the ECD, the AED is a universally sensitive, highly linear, elementally specific detector. The new GC-AED system is being used to measure chlorodifluoromethane (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), and other fluorinated compounds in one liter water samples to study their potential as age dating tracers. HCFC-22 is a

  11. Wairakei tracer tests 1983

    International Nuclear Information System (INIS)

    McCabe, W.J.; Barry, B.J.

    1984-05-01

    Tracer tests, with and without, hot water reinjection into WK213 showed returns of tracer iodine-131; in wells in both the Waiora Valley and the eastern end of the field. The effect of reinjection at a rate of 200 cu. m/h was to reduce the arrived time from 15 to 7 days. Increasing the rate of reinjection into WK62 from 30 cu. m/h to 200 cu. m/h seemed to increase the initial velocity of the tracer wave and the distance it moved. However, returns were recorded only in the adjacent wells WK61 and WK63 with a very small, and three days delayed, response in WK43

  12. International Harmonization and Cooperation in the Validation of Alternative Methods.

    Science.gov (United States)

    Barroso, João; Ahn, Il Young; Caldeira, Cristiane; Carmichael, Paul L; Casey, Warren; Coecke, Sandra; Curren, Rodger; Desprez, Bertrand; Eskes, Chantra; Griesinger, Claudius; Guo, Jiabin; Hill, Erin; Roi, Annett Janusch; Kojima, Hajime; Li, Jin; Lim, Chae Hyung; Moura, Wlamir; Nishikawa, Akiyoshi; Park, HyeKyung; Peng, Shuangqing; Presgrave, Octavio; Singer, Tim; Sohn, Soo Jung; Westmoreland, Carl; Whelan, Maurice; Yang, Xingfen; Yang, Ying; Zuang, Valérie

    The development and validation of scientific alternatives to animal testing is important not only from an ethical perspective (implementation of 3Rs), but also to improve safety assessment decision making with the use of mechanistic information of higher relevance to humans. To be effective in these efforts, it is however imperative that validation centres, industry, regulatory bodies, academia and other interested parties ensure a strong international cooperation, cross-sector collaboration and intense communication in the design, execution, and peer review of validation studies. Such an approach is critical to achieve harmonized and more transparent approaches to method validation, peer-review and recommendation, which will ultimately expedite the international acceptance of valid alternative methods or strategies by regulatory authorities and their implementation and use by stakeholders. It also allows achieving greater efficiency and effectiveness by avoiding duplication of effort and leveraging limited resources. In view of achieving these goals, the International Cooperation on Alternative Test Methods (ICATM) was established in 2009 by validation centres from Europe, USA, Canada and Japan. ICATM was later joined by Korea in 2011 and currently also counts with Brazil and China as observers. This chapter describes the existing differences across world regions and major efforts carried out for achieving consistent international cooperation and harmonization in the validation and adoption of alternative approaches to animal testing.

  13. Tracer monitoring of enhanced oil recovery projects

    Directory of Open Access Journals (Sweden)

    Kleven R.

    2013-05-01

    Full Text Available In enhanced oil recovery (EOR, chemicals are injected into the oil reservoir, either to increase macroscopic sweep efficiency, or to reduce remaining oil saturation in swept zones. Tracers can be used to identify reservoirs that are specifically suited for EOR operations. Injection of a selection of partitioning tracers, combined with frequent sample analysis of produced fluids, provides information suited for estimation of residual oil saturation. Tracers can also be used to evaluate and optimize the application of EOR chemicals in the reservoir. Suitable tracers will follow the EOR chemicals and assist in evaluation of retention, degradation or trapping. In addition to field applications, tracers also have a large potential as a tool to perform mechanistic studies of EOR chemicals in laboratory experiments. By labelling EOR chemicals with radioactive isotopes of elements such as H, C and S, detailed studies of transport mechanisms can be carried out. Co-injection of labelled compounds in dynamic flooding experiments in porous media will give information about retention or separation of the unique compounds constituting the chemical formulation. Separation of such compounds may be detrimental to obtaining the EOR effect expected. The paper gives new information of specific methods, and discusses current status for use of tracers in EOR operations.

  14. Method of starting internal pumps of a nuclear reactor

    International Nuclear Information System (INIS)

    Kumagami, Shoji.

    1985-01-01

    Purpose: To reduce the noise effects by decreasing the invading current into the main line upon starting an internal pump type nuclear reactor adapted to forcively recycle the reactor water by a plurality of internal pumps. Method: A plurality of internal pumps are divided into several groups and, upon starting pumps belonging to the individual unit group, the starting instances for the respective pumps are deviated to reduce the surges applied to the main line and suppress the invading current lower to reduce the earth noises. As a result, effects caused to other devices or equipments can be moderated to improve the reliability. Furthermore, by actuating the respective pumps on every group units in a starting pattern along the orthogonal line, flow rate distribution in the reactor can be balanced. Then, the instability region during low rotation of pumps, that is, instability of the flow rate near the resonance frequency can be decreased. (Kawakami, Y.)

  15. Using Multi-Isotope Tracer Methods to Understand the Sources of Nitrate in Aerosols, Fog and River Water in Podocarpus National Forest, Ecuador

    Science.gov (United States)

    Brothers, L. A.; Dominguez, G.; Fabian, P.; Thiemens, M. H.

    2008-12-01

    sulfate and nitrate concentrations in rain and fog water by standard methods to investigate water and nutrient pathways along with data from satellite and ground based remote sensing, observations and numerical models. We hope to pair this with a multi-isotope tracer method and NOAA Hysplit Back trajectories, and satellite imagery for information about the number of fires burning in the region to help identify sources of the high nitrate deposition.

  16. Models for tracer flow

    International Nuclear Information System (INIS)

    Zuber, A.

    1983-01-01

    A review and discussion is given of mathematical models used for interpretation of tracer experiments in hydrology. For dispersion model, different initial and boundary conditions are related to different injection and detection modes. Examples of applications of various models are described and commented. (author)

  17. Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms

    CERN Document Server

    Williams, J J

    2013-01-01

    Modern design methods of Automotive Cam Design require the computation of a range of parameters. This book provides a logical sequence of steps for the derivation of the relevant equations from first principles, for the more widely used cam mechanisms. Although originally derived for use in high performance engines, this work is equally applicable to the design of mass produced automotive and other internal combustion engines.   Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms provides the equations necessary for the design of cam lift curves with an associated smooth acceleration curve. The equations are derived for the kinematics and kinetics of all the mechanisms considered, together with those for cam curvature and oil entrainment velocity. This permits the cam shape, all loads, and contact stresses to be evaluated, and the relevant tribology to be assessed. The effects of asymmetry on the manufacture of cams for finger follower and offset translating curved followers is ...

  18. Standard methods for sampling freshwater fishes: opportunities for international collaboration

    OpenAIRE

    Bonar, Scott A.; Mercado-Silva, Norman; Hubert, Wayne A.; Beard, T. Douglas; Dave, Göran; Kubečka, Jan; Graeb, Brian D.S.; Lester, Nigel P.; Porath, Mark; Winfield, Ian J.

    2017-01-01

    With publication of Standard Methods for Sampling North American Freshwater Fishes in 2009, the American Fisheries Society (AFS) recommended standard procedures for North America. To explore interest in standardizing at intercontinental scales, a symposium attended by international specialists in freshwater fish sampling was convened at the 145th Annual AFS Meeting in Portland, Oregon, in August 2015. Participants represented all continents except Australia and Antarctica and were employed by...

  19. International Franchising as a Method for Business Expansion

    OpenAIRE

    Karpushina, Darya Evgenjevna

    2009-01-01

    The present Master Thesis investigates the concept of international franchising from both business and legal standpoints. The actuality of the topic is obvious: Franchising becomes one of the most perspective and fast-developing method for business expansion, and this Diploma was written as a reflection of such tendency. In the meantime, Franchising is an extremely complex and arguable business issue and still causes a kind of confusion in people's mind. For this reason, my effort in this Wor...

  20. International Conference on Multiscale Methods and Partial Differential Equations.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Hou

    2006-12-12

    The International Conference on Multiscale Methods and Partial Differential Equations (ICMMPDE for short) was held at IPAM, UCLA on August 26-27, 2005. The conference brought together researchers, students and practitioners with interest in the theoretical, computational and practical aspects of multiscale problems and related partial differential equations. The conference provided a forum to exchange and stimulate new ideas from different disciplines, and to formulate new challenging multiscale problems that will have impact in applications.

  1. International Conference on Spectral and High-Order Methods

    CERN Document Server

    Dumont, Ney; Hesthaven, Jan

    2017-01-01

    This book features a selection of high-quality papers chosen from the best presentations at the International Conference on Spectral and High-Order Methods (2016), offering an overview of the depth and breadth of the activities within this important research area. The carefully reviewed papers provide a snapshot of the state of the art, while the extensive bibliography helps initiate new research directions.

  2. Inspection of internal tank welds using the ACFM inspection method

    International Nuclear Information System (INIS)

    Topp, D.A.; Lugg, M.C.

    2009-01-01

    The paper describes recent developments of the ACFM technique and describes several case studies where ACFM has been used to inspect the internal plate welds on large steel storage tanks in refineries. For weld inspection, conventional methods such as magnetic particle inspection or vacuum box testing are generally used. This paper presents comparisons of the results from ACFM with those from the conventional methods, from which conclusions are drawn as to the benefits this technique offers in terms of cost, time savings and inspection reliability. (author)

  3. Reactor internals vibration monitoring by neutron noise methods in PWRs

    International Nuclear Information System (INIS)

    Pazsit, I.; Por, G.; Lux, I.

    1983-01-01

    Certain elements of PWR cores such as control/fuel rods or cassettes, or other parts of reactor internals, often represent a vibration problem. Early analyses at operating PWR plant revealed that these vibrations can be detected by in-core neutron detectors, opening up the possibility of vibration monitoring and diagnostics by noise methods. Theoretical methods of calculating vibration induced neutron noise and its application to vibration diagnostics are summarized. Experiments to check theoretical conclusions are under way at the Central Research Institute for Physics, Budapest. (author)

  4. Xanthine tracers and their preparation

    International Nuclear Information System (INIS)

    Groman, E.V.; Cabelli, M.D.

    1980-01-01

    Compounds useful as tracers in the radioimmunoassay of xanthine derivatives such as theophylline and pharmacologically related drugs are described. They are substituted xanthines in which at least one substituted radical contains radioiodine. The tracers are made by linking radioiodinatable or preradioiodinated radicals to the xanthine derivative which is to be assayed. The tracers may be employed in known radioimmunoassay techniques. (author)

  5. Use of radioactive tracers in dynamic sedimentology

    International Nuclear Information System (INIS)

    Tola, Francois.

    1982-01-01

    In the first part, developments in the use of radioactive tracers in sedimentology are recalled together with the corresponding fields of application and the identities of the main users. The state-of-the-art in France is also discussed; The main characteristics of the method are then described and compared with those of more classical methods. The results that can be obtained with tracer methods are then outlined. The criteria employed to establish the granulometry characteristics of the tracer, the particular radioisotope to be used, and the masses and activities involved, are treated. A list is then given of the main isotopes available in France and their characteristics. The various different labelling techniques employed are studied together with their respective advantages and disadvantages. The special case of pelitic sediments is mentioned. The use of reduced model isotope generators, double labelling and applications to studies of the mud plug in the Gironde Estuary are also discussed. The methods and materials used for injecting and detecting tracers are described, emphasis being given to the economic factors associated with the use of radioactive tracers in sedimentology. The second part of the report contains two chapters: - studies of transport by driftage: presentation and analysis of results and the application of the Count Rate Balance method to obtain quantitative information on transport; - studies of in-suspension transport of fine sediments in the sea: the procedures adopted from the moment when the tracer is introduced up to the time when the results are analyzed and interpreted, enables the trajectories and mean velocities of the transported sediments to be determined together with their degree of dilution and their settling speeds and rates; it is also possible to investigate the evolution and horizontal dispersion of the sediments in this way. Results from recent experiments are presented in both parts of the report

  6. Biologic data, models, and dosimetric methods for internal emitters

    International Nuclear Information System (INIS)

    Weber, D.A.

    1990-01-01

    The absorbed radiation dose from internal emitters has been and will remain a pivotal factor in assessing risk and therapeutic utility in selecting radiopharmaceuticals for diagnosis and treatment. Although direct measurements of absorbed dose and dose distributions in vivo have been and will continue to be made in limited situations, the measurement of the biodistribution and clearance of radiopharmaceuticals in human subjects and the use of this data is likely to remain the primary means to approach the calculation and estimation of absorbed dose from internal emitters over the next decade. Since several approximations are used in these schema to calculate dose, attention must be given to inspecting and improving the application of this dosimetric method as better techniques are developed to assay body activity and as more experience is gained in applying these schema to calculating absorbed dose. Discussion of the need for considering small scale dosimetry to calculate absorbed dose at the cellular level will be presented in this paper. Other topics include dose estimates for internal emitters, biologic data mathematical models and dosimetric methods employed. 44 refs

  7. Tracer tests Wairakei

    International Nuclear Information System (INIS)

    McCabe, W.J.; Manning, M.R.; Barry, B.J.

    1980-07-01

    The report summarises the radioactive tracer tests, using iodine-131 and bromine-82, made in the Wairakei geothermal field over the period 1978-80. Injection of tracer into three wells with strong cool water downflows at about 300-400m below ground level, produced strong rapid responses from the only deep wells feeding from about 800-1000m and lying in the south-westerly direction from the injection wells, i.e. parallel to the fault planes. Shallower wells, even though in some cases much closer to the injection well, reacted much more slowly. Velocities, as measured by peak arrival times, as high as 22m/h over 200m and 11m/h over 650m, were found. The flow patterns for the cool water feeds to the production area are discussed

  8. Standard methods for sampling freshwater fishes: Opportunities for international collaboration

    Science.gov (United States)

    Bonar, Scott A.; Mercado-Silva, Norman; Hubert, Wayne A.; Beard, Douglas; Dave, Göran; Kubečka, Jan; Graeb, Brian D. S.; Lester, Nigel P.; Porath, Mark T.; Winfield, Ian J.

    2017-01-01

    With publication of Standard Methods for Sampling North American Freshwater Fishes in 2009, the American Fisheries Society (AFS) recommended standard procedures for North America. To explore interest in standardizing at intercontinental scales, a symposium attended by international specialists in freshwater fish sampling was convened at the 145th Annual AFS Meeting in Portland, Oregon, in August 2015. Participants represented all continents except Australia and Antarctica and were employed by state and federal agencies, universities, nongovernmental organizations, and consulting businesses. Currently, standardization is practiced mostly in North America and Europe. Participants described how standardization has been important for management of long-term data sets, promoting fundamental scientific understanding, and assessing efficacy of large spatial scale management strategies. Academics indicated that standardization has been useful in fisheries education because time previously used to teach how sampling methods are developed is now more devoted to diagnosis and treatment of problem fish communities. Researchers reported that standardization allowed increased sample size for method validation and calibration. Group consensus was to retain continental standards where they currently exist but to further explore international and intercontinental standardization, specifically identifying where synergies and bridges exist, and identify means to collaborate with scientists where standardization is limited but interest and need occur.

  9. Preparation of porous zirconia microspheres by internal gelation method

    International Nuclear Information System (INIS)

    Pathak, Sachin S.; Pius, I.C.; Bhanushali, R.D.; Rao, T.V. Vittal; Mukerjee, S.K.

    2008-01-01

    A modified internal gelation process for the preparation of porous zirconia microspheres has been developed. The conventional method has been modified by adding a surfactant in the feed broth. The effects of variation of surfactant concentration, washing techniques and temperature of calcination on the pore volume and the surface area of the microspheres have been studied. The conditions were optimized to obtain porous stable microspheres suitable for various applications. The microspheres were characterized by surface area analysis, pore volume analysis, thermogravimetric analysis and X-ray diffraction. The ion exchange behavior was studied using pH titration

  10. UO2 microspheres obtainment through the internal gelation methods

    International Nuclear Information System (INIS)

    Sterba, M.E.; Gomez Constenla, A.

    1987-01-01

    UO 2 microspheres obtainment process through the internal gelation method which allows the spheres' obtainment of uniform size is detailed herein, varying the same among 0.3 and 1.7 mm of diameter. The sintered density reaches 10.78 g/cm 3 , permitting the fuels fabrication dispersed and vibro-compacted fuels. The trichloroethylene use implementation as gelation agent is described, thus reducing the number of stages in the microspheres fabrication. At the same time, the uranium sun composition has been modified so as to be compatible with the use solvent. (Author)

  11. International intercalibration as a method for control of radiochemical analyses

    International Nuclear Information System (INIS)

    Angelova, A.; Totseva, R.; Karaivanova, R.; Dandulova, Z.; Botsova, L.

    1994-01-01

    The participation of the Radioecology Section at the National Centre for Radiology and Radiation Protection (NCRRP) in the International Interlaboratory Comparison of radiochemical analyses organized by WHO is reported. The method of evaluating accuracy of the results from inter calibrations concerning radionuclide determination of environmental samples is outlined. The data from analysis of cesium 137, strontium 90 and radium 226 in milk, sediments, soil and seaweed made by 21 laboratories are presented. They show a good accuracy values of the results from NCRRP. 1 tab. 2 figs., 6 refs

  12. International intercomparison of neutron spectra evaluating methods using activation detectors

    International Nuclear Information System (INIS)

    Fischer, A.

    1975-06-01

    The international intercomparison of neutron spectrum evaluation methods using activation detectors was organized by the IAEA in 1971 - 1972. All of the contributions and the results of a critical evaluation are presented here. The spectra of different contributors are compared to a reference spectrum by means of different integrals and weighting functions. Different cross section sets, foil numbers, energy point systems, guess spectra used by the contributors cause differences in the resulting spectra. The possible ways of separating these effects are also investigated. Suggestions are made for the organization of a new intercomparison on the basis of more uniform input data. (orig.) [de

  13. Measurements of waste tank passive ventilation rates using tracer gases

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Olsen, K.B.; Sklarew, D.S.; Evans, J.C.; Remund, K.M.

    1997-09-01

    This report presents the results of ventilation rate studies of eight passively ventilated high-level radioactive waste tanks using tracer gases. Head space ventilation rates were determined for Tanks A-101, AX-102, AX-103, BY-105, C-107, S-102, U-103, and U-105 using sulfur hexafluoride (SF 6 ) and/or helium (He) as tracer gases. Passive ventilation rates are needed for the resolution of several key safety issues. These safety issues are associated with the rates of flammable gas production and ventilation, the rates at which organic salt-nitrate salt mixtures dry out, and the estimation of organic solvent waste surface areas. This tracer gas study involves injecting a tracer gas into the tank headspace and measuring its concentration at different times to establish the rate at which the tracer is removed by ventilation. Tracer gas injection and sample collection were performed by SGN Eurisys Service Corporation and/or Lockheed Martin Hanford Corporation, Characterization Project Operations. Headspace samples were analyzed for He and SF 6 by Pacific Northwest National Laboratory (PNNL). The tracer gas method was first demonstrated on Tank S-102. Tests were conducted on Tank S-102 to verify that the tracer gas was uniformly distributed throughout the tank headspace before baseline samples were collected, and that mixing was sufficiently vigorous to maintain an approximately uniform distribution of tracer gas in the headspace during the course of the study. Headspace samples, collected from a location about 4 in away from the injection point and 15, 30, and 60 minutes after the injection of He and SF 6 , indicated that both tracer gases were rapidly mixed. The samples were found to have the same concentration of tracer gases after 1 hour as after 24 hours, suggesting that mixing of the tracer gas was essentially complete within 1 hour

  14. Methane emission quantification from landfills using a double tracer approach

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Samuelsson, J.; Fredenslund, Anders Michael

    2007-01-01

    A tracer method was successfully used for quantification of the whole methane (CH4) emission from Fakse landfill. By using two different tracers the emission from different sections of the landfill could be quantified. Furthermore, is was possible to determine the emissions from local on site...

  15. Enhanced Oil Recovery: Aqueous Flow Tracer Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Rovani; John Schabron

    2009-02-01

    A low detection limit analytical method was developed to measure a suite of benzoic acid and fluorinated benzoic acid compounds intended for use as tracers for enhanced oil recovery operations. Although the new high performance liquid chromatography separation successfully measured the tracers in an aqueous matrix at low part per billion levels, the low detection limits could not be achieved in oil field water due to interference problems with the hydrocarbon-saturated water using the system's UV detector. Commercial instrument vendors were contacted in an effort to determine if mass spectrometry could be used as an alternate detection technique. The results of their work demonstrate that low part per billion analysis of the tracer compounds in oil field water could be achieved using ultra performance liquid chromatography mass spectrometry.

  16. On the use of liquid scintillation counting of 51Cr and 14C in the twin tracer method of measuring assimilation efficiency

    International Nuclear Information System (INIS)

    Cammen, L.M.

    1977-01-01

    Calow and Fletcher (1972) calculated assimilation efficiency from the ratio of an assimilated radiotracer ( 14 C) to a non-assimilated tracer ( 51 Cr) in food and feces. Wightman (1975) improved the efficiency of their technique by using liquid scintillation to count both isotopes simultaneously, but stated incorrectly that it was not necessary to convert count per minute (CPM) to disintegration per minute (DPM). Unless the CPM data are corrected for quenching and converted to DPM prior to calculation of assimilation efficiency, a significant error may be introduced. (orig.) [de

  17. Development of radioisotope tracer technology

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee; Park, Soon Chul; Lim, Dong Soon; Kim, Jae Ho; Lee, Jae Choon; Lee, Doo Sung; Cho, Yong Suk; Shin, Sung Kuan

    2000-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by proton beam and the correlation between the measured activity loss and the amount of wear was established. The equipment was developed to adjust the energy of proton which collides with the surface of tappet. The tracer project team has participated into the tracer test for estimating the efficiency of RFCC system in SK cooperation. From the experiment the tracer team has obtained the primary elements to be considered for judging the efficiency of RFCC unit. By developing the tracer techniques to test huge industrial units like RFCC, the tracer team will be able to support the local industries that require technical services to solve any urgent trouble. (author)

  18. Use of labeled compounds in tracer experiments

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The use of radiotracers in research has become common. This chapter looks at some of the underlying assumptions and advantages of labeled compounds: advantages of radiotracers; availability of suitable tracers and labeled compounds; purity of labeled compounds; autoradiolysis; storage of labeled compounds; detection systems for chromatography and electrophoretic methods. 14 refs., 2 figs

  19. Using radioactive tracer technique in municipal hygiene

    International Nuclear Information System (INIS)

    Yurasova, O.I.

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology

  20. Using radioactive tracer technique in municipal hygiene

    Energy Technology Data Exchange (ETDEWEB)

    Yurasova, O I [Institut Obshchej i Kommunal' noj Gigieny, Moscow (USSR)

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology.

  1. Pipeline leak detection using volatile tracers

    International Nuclear Information System (INIS)

    Thompson, G.M.; Golding, R.D.

    1993-01-01

    A method of leak detection for underground storage tanks and pipelines adds volatile tracers to the products in the tanks and analyzes the surrounding shallow soil gases for tracer vapors. This method has several advantages: the success of the test is not limited by the size and structural design of the vessels, tanks can be tested at any fill level without taking the tank out of service, the location of a leak along a pipeline is clearly marked by the location of the tracer, and liquid leaks as small as 0.2 liters per hour (lph) can be detected. A limitation is: the backfill material must have some degree of air permeability in the zone above the water table. Several field tests document the success achieved using this method. A tracer leak detection system was installed at Homestead AFB after several other testing methods failed to locate a leak at a valve pit location along approximately 4 kilometers of fuel transfer piping. The leak was detected to the side of the valve pit at a depth of approximately 2.5 meters below the ground surface. Another installation of Edwards AFB involved the collection of 415 soil gas samples along approximately 3,050 meters of 15.25-centimeter fiberglass pipeline. Fourteen separate leaks were detected

  2. Tracer Testing for Estimating Heat Transfer Area in Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, Karsten; van Heel, Ton; Shan, Chao

    2004-05-12

    A key parameter governing the performance and life-time of a Hot Fractured Rock (HFR) reservoir is the effective heat transfer area between the fracture network and the matrix rock. We report on numerical modeling studies into the feasibility of using tracer tests for estimating heat transfer area. More specifically, we discuss simulation results of a new HFR characterization method which uses surface-sorbing tracers for which the adsorbed tracer mass is proportional to the fracture surface area per unit volume. Sorption in the rock matrix is treated with the conventional formulation in which tracer adsorption is volume-based. A slug of solute tracer migrating along a fracture is subject to diffusion across the fracture walls into the adjacent rock matrix. Such diffusion removes some of the tracer from the fluid in the fractures, reducing and retarding the peak in the breakthrough curve (BTC) of the tracer. After the slug has passed the concentration gradient reverses, causing back-diffusion from the rock matrix into the fracture, and giving rise to a long tail in the BTC of the solute. These effects become stronger for larger fracture-matrix interface area, potentially providing a means for estimating this area. Previous field tests and modeling studies have demonstrated characteristic tailing in BTCs for volatile tracers in vapor-dominated reservoirs. Simulated BTCs for solute tracers in single-phase liquid systems show much weaker tails, as would be expected because diffusivities are much smaller in the aqueous than in the gas phase, by a factor of order 1000. A much stronger signal of fracture-matrix interaction can be obtained when sorbing tracers are used. We have performed simulation studies of surface-sorbing tracers by implementing a model in which the adsorbed tracer mass is assumed proportional to the fracture-matrix surface area per unit volume. The results show that sorbing tracers generate stronger tails in BTCs, corresponding to an effective

  3. New method to analyze internal disruptions with tomographic reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Tanzi, C.P. [EURATOM-FOM Association, FOM-Instituut voor Plasmafysica Rijnhuizen, P.O. BOX 1207, 3430 BE Nieuwegein (The Netherlands); de Blank, H.J. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-IPP Association, 85740 Garching (Germany)

    1997-03-01

    Sawtooth crashes have been investigated on the Rijnhuizen Tokamak Project (RTP) [N. J. Lopes Cardozo {ital et al.}, {ital Proceedings of the 14th International Conference on Plasma Physics and Controlled Nuclear Fusion Research}, W{umlt u}rzburg, 1992 (International Atomic Energy Agency, Vienna, 1993), Vol. 1, p. 271]. Internal disruptions in tokamak plasmas often exhibit an m=1 poloidal mode structure prior to the collapse which can be clearly identified by means of multicamera soft x-ray diagnostics. In this paper tomographic reconstructions of such m=1 modes are analyzed with a new method, based on magnetohydrodynamic (MHD) invariants computed from the two-dimensional emissivity profiles, which quantifies the amount of profile flattening not only after the crash but also during the precursor oscillations. The results are interpreted by comparing them with two models which simulate the measurements of the m=1 redistribution of soft x-ray emissivity prior to the sawtooth crash. One model is based on the magnetic reconnection model of Kadomtsev. The other involves ideal MHD motion only. In cases where differences in magnetic topology between the two models cannot be seen in the tomograms, the analysis of profile flattening has an advantage. The analysis shows that in RTP the clearly observed m=1 displacement of some sawteeth requires the presence of convective ideal MHD motion, whereas other precursors are consistent with magnetic reconnection of up to 75{percent} of the magnetic flux within the q=1 surface. The possibility of ideal interchange combined with enhanced cross-field transport is not excluded. {copyright} {ital 1997 American Institute of Physics.}

  4. New method to analyze internal disruptions with tomographic reconstructions

    International Nuclear Information System (INIS)

    Tanzi, C.P.; de Blank, H.J.

    1997-01-01

    Sawtooth crashes have been investigated on the Rijnhuizen Tokamak Project (RTP) [N. J. Lopes Cardozo et al., Proceedings of the 14th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Wuerzburg, 1992 (International Atomic Energy Agency, Vienna, 1993), Vol. 1, p. 271]. Internal disruptions in tokamak plasmas often exhibit an m=1 poloidal mode structure prior to the collapse which can be clearly identified by means of multicamera soft x-ray diagnostics. In this paper tomographic reconstructions of such m=1 modes are analyzed with a new method, based on magnetohydrodynamic (MHD) invariants computed from the two-dimensional emissivity profiles, which quantifies the amount of profile flattening not only after the crash but also during the precursor oscillations. The results are interpreted by comparing them with two models which simulate the measurements of the m=1 redistribution of soft x-ray emissivity prior to the sawtooth crash. One model is based on the magnetic reconnection model of Kadomtsev. The other involves ideal MHD motion only. In cases where differences in magnetic topology between the two models cannot be seen in the tomograms, the analysis of profile flattening has an advantage. The analysis shows that in RTP the clearly observed m=1 displacement of some sawteeth requires the presence of convective ideal MHD motion, whereas other precursors are consistent with magnetic reconnection of up to 75% of the magnetic flux within the q=1 surface. The possibility of ideal interchange combined with enhanced cross-field transport is not excluded. copyright 1997 American Institute of Physics

  5. The international INTRAVAL project. Phase 2, working group 1 report. Flow and tracer experiments in unsaturated tuff and soil. Las Cruces trench and Apache Leap tuff studies

    International Nuclear Information System (INIS)

    Nicholson, T.J.; Guzman-Guzman, A.; Hills, R.; Rasmussen, T.C.

    1997-01-01

    The Working Group 1 final report summaries two test case studies, the Las Cruces Trench (LCT), and Apache Leap Tuff Site (ALTS) experiments. The objectives of these two field studies were to evaluate models for water flow and contaminant transport in unsaturated, heterogeneous soils and fractured tuff. The LCT experiments were specifically designed to test various deterministic and stochastic models of water flow and solute transport in heterogeneous, unsaturated soils. Experimental data from the first tow LCT experiments, and detailed field characterisation studies provided information for developing and calibrating the models. Experimental results from the third experiment were held confidential from the modellers, and were used for model comparison. Comparative analyses included: point comparisons of water content; predicted mean behavior for water flow; point comparisons of solute concentrations; and predicted mean behavior for tritium transport. These analyses indicated that no model, whether uniform or heterogeneous, proved superior. Since the INTRAVAL study, however, a new method has been developed for conditioning the hydraulic properties used for flow and transport modelling based on the initial field-measured water content distributions and a set of scale-mean hydraulic parameters. Very good matches between the observed and simulated flow and transport behavior were obtained using the conditioning procedure, without model calibration. The ALTS experiments were designed to evaluate characterisation methods and their associated conceptual models for coupled matrix-fracture continua over a range of scales (i.e., 2.5 centimeter rock samples; 10 centimeter cores; 1 meter block; and 30 meter boreholes). Within these spatial scales, laboratory and field tests were conducted for estimating pneumatic, thermal, hydraulic, and transport property values for different conceptual models. The analyses included testing of current conceptual, mathematical and physical

  6. Radionuclides as tracers

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Importance of radioisotopes in medicine is because of their two characteristics: their biological behaviour is identical to their stable counterparts, and because they are radioactive their emissions can be detected by a suitable instrument. All isotopes of iodine will behave in the same way and will concentrate in the thyroid gland. There is no way of detecting the stable, natural iodine in the thyroid gland, but the presence of radioactive iodine can be detected externally in vivo by a detector. Thus, the radioactive iodine becomes a tracer, a sport of a spy, which mimics the behaviour of natural iodine and relays information to a detector. The radioactive tracers are popular because of the ease with which they can be detected in vivo and the fact that the measurement of their presence in the body can be in quantitative terms. The measurement can be very accurate and sensitive. Whenever the measurements can be done in vivo, the information is obtained in dynamic terms, as it is happening, as if the physiological events become transparent

  7. 31st International Colloquium in Group Theoretical Methods in Physics

    CERN Document Server

    Gazeau, Jean-Pierre; Faci, Sofiane; Micklitz, Tobias; Scherer, Ricardo; Toppan, Francesco

    2017-01-01

    This proceedings records the 31st International Colloquium on Group Theoretical Methods in Physics (“Group 31”). Plenary-invited articles propose new approaches to the moduli spaces in gauge theories (V. Pestun, 2016 Weyl Prize Awardee), the phenomenology of neutrinos in non-commutative space-time, the use of Hardy spaces in quantum physics, contradictions in the use of statistical methods on complex systems, and alternative models of supersymmetry. This volume’s survey articles broaden the colloquia’s scope out into Majorana neutrino behavior, the dynamics of radiating charges, statistical pattern recognition of amino acids, and a variety of applications of gauge theory, among others. This year’s proceedings further honors Bertram Kostant (2016 Wigner Medalist), as well as S.T. Ali and L. Boyle, for their life-long contributions to the math and physics communities. The aim of the ICGTMP is to provide a forum for physicists, mathematicians, and scientists of related disciplines who develop or apply ...

  8. 8th International Conference on Boundary Element Methods

    CERN Document Server

    Brebbia, C

    1986-01-01

    The International Conference on Boundary Element Methods in Engineering was started in 1978 with the following objectives: i) To act as a focus for BE research at a time when the technique wasjust emerging as a powerful tool for engineering analysis. ii) To attract new as weIl as established researchers on Boundary Elements, in order to maintain its vitality and originality. iii) To try to relate the Boundary Element Method to other engineering techniques in an effort to help unify the field of engineering analysis, rather than to contribute to its fragmentation. These objectives were achieved during the last 7 conferences and this meeting - the eighth - has continued to be as innovative and dynamic as any ofthe previous conferences. Another important aim ofthe conference is to encourage the participation of researchers from as many different countries as possible and in this regard it is a policy of the organizers to hold the conference in different locations. It is easy to forget when working on scientific ...

  9. Tracing salmon to their birthplace by activable tracer technique

    International Nuclear Information System (INIS)

    Shibuya, Masao

    1978-01-01

    Activable tracer technique was applied to trace the recurrent migration of white salmons, as a typical example of employing radioactivation analysis to the study of agricultural and marinefields. Europium was adopted because it is easy to use technically with less influence on fish body and easy to detect, and its remaining time is very long. Artificially hatched young white salmons were stocked in the Saibetsu River after being raised for a month with europium-containing feed. These stocked fish were labeled by fin-cutting method. Recurrent salmons (fin cutting-labeled fish) were then collected and dissected. The fishes were divided into otoliths, scales, flesh, internal organs, gills, bones, etc., and irradiated for 5 min in JRR-2 reactor of Japan Atomic Energy Research Institute. Europium was detected from the scales and otoliths of 3 to 4 year stocked adult fishes by γ-spectrometry of Eu. This proved the availability of activable tracer method for tracing the recurrent migration of salmons. (Kobatake, H.)

  10. Guidebook on radioisotope tracers in industry

    International Nuclear Information System (INIS)

    1990-01-01

    The idea of using tracers (chemical, dyes, etc.) in the investigation of complex physical phenomena has always attracted the attention of scientists and engineers. When radioactive isotopes became available it was immediately recognized that they offered an almost ideal solution to tracer selection. This book is devoted to reviewing the present status of the tracer method as such and to its applications to those branches of industry which have derived large benefits from the use of this modern technology. The main objectives of the IAEA's Industrial Applications and Chemistry Section is to help Member States in introducing to their own industries the different isotope and radiation techniques which have become available as a result of developments in the nuclear sciences. This section proposed the preparation of this guidebook, putting together various radiotracer methods and the experience obtained so far in their industrial use. Chapters 2 to 4 cover the general concept of tracers, technology and safety aspects, as well as data evaluation and interpretation. In chapter 5, therefore, general applications are discussed. In chapter 6, specialists in selected fields discuss their experience in radiotracer applications in various types of industrial activity. Most case studies are illustrated by at least one detailed example of an experiment carried out at an industrial installation. Current trends in the development of radiotracer methods are discussed in chapter 7, from both a theoretical and a practical viewpoint. Some possible new RTT applications in the future are also discussed here. Sealed radioactive sources are used almost as often as radioisotope tracers in industrial measurements. Annex I gives a short review of these techniques. Readers who are interested in the basic principles of radioisotope production will find the necessary information in Annex II. Annexes III, V and VI provide a demonstration of fundamental relations and properties; useful

  11. Validation of internal dosimetry protocols based on stochastic method

    International Nuclear Information System (INIS)

    Mendes, Bruno M.; Fonseca, Telma C.F.; Almeida, Iassudara G.; Trindade, Bruno M.; Campos, Tarcisio P.R.

    2015-01-01

    Computational phantoms adapted to Monte Carlo codes have been applied successfully in radiation dosimetry fields. NRI research group has been developing Internal Dosimetry Protocols - IDPs, addressing distinct methodologies, software and computational human-simulators, to perform internal dosimetry, especially for new radiopharmaceuticals. Validation of the IDPs is critical to ensure the reliability of the simulations results. Inter comparisons of data from literature with those produced by our IDPs is a suitable method for validation. The aim of this study was to validate the IDPs following such inter comparison procedure. The Golem phantom has been reconfigured to run on MCNP5. The specific absorbed fractions (SAF) for photon at 30, 100 and 1000 keV energies were simulated based on the IDPs and compared with reference values (RV) published by Zankl and Petoussi-Henss, 1998. The SAF average differences from RV and those obtained in IDP simulations was 2.3 %. The SAF largest differences were found in situations involving low energy photons at 30 keV. The Adrenals and thyroid, i.e. the lowest mass organs, had the highest SAF discrepancies towards RV as 7.2 % and 3.8 %, respectively. The statistic differences of SAF applying our IDPs from reference values were considered acceptable at the 30, 100 and 1000 keV spectra. We believe that the main reason for the discrepancies in IDPs run, found in lower masses organs, was due to our source definition methodology. Improvements of source spatial distribution in the voxels may provide outputs more consistent with reference values for lower masses organs. (author)

  12. Validation of internal dosimetry protocols based on stochastic method

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Bruno M.; Fonseca, Telma C.F., E-mail: bmm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Almeida, Iassudara G.; Trindade, Bruno M.; Campos, Tarcisio P.R., E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2015-07-01

    Computational phantoms adapted to Monte Carlo codes have been applied successfully in radiation dosimetry fields. NRI research group has been developing Internal Dosimetry Protocols - IDPs, addressing distinct methodologies, software and computational human-simulators, to perform internal dosimetry, especially for new radiopharmaceuticals. Validation of the IDPs is critical to ensure the reliability of the simulations results. Inter comparisons of data from literature with those produced by our IDPs is a suitable method for validation. The aim of this study was to validate the IDPs following such inter comparison procedure. The Golem phantom has been reconfigured to run on MCNP5. The specific absorbed fractions (SAF) for photon at 30, 100 and 1000 keV energies were simulated based on the IDPs and compared with reference values (RV) published by Zankl and Petoussi-Henss, 1998. The SAF average differences from RV and those obtained in IDP simulations was 2.3 %. The SAF largest differences were found in situations involving low energy photons at 30 keV. The Adrenals and thyroid, i.e. the lowest mass organs, had the highest SAF discrepancies towards RV as 7.2 % and 3.8 %, respectively. The statistic differences of SAF applying our IDPs from reference values were considered acceptable at the 30, 100 and 1000 keV spectra. We believe that the main reason for the discrepancies in IDPs run, found in lower masses organs, was due to our source definition methodology. Improvements of source spatial distribution in the voxels may provide outputs more consistent with reference values for lower masses organs. (author)

  13. Tracer gas diffusion sampling test plan

    International Nuclear Information System (INIS)

    Rohay, V.J.

    1993-01-01

    Efforts are under way to employ active and passive vapor extraction to remove carbon tetrachloride from the soil in the 200 West Area an the Hanford Site as part of the 200 West Area Carbon Tetrachloride Expedited Response Action. In the active approach, a vacuum is applied to a well, which causes soil gas surrounding the well to be drawn up to the surface. The contaminated air is cleaned by passage through a granular activated carbon bed. There are questions concerning the radius of influence associated with application of the vacuum system and related uncertainties about the soil-gas diffusion rates with and without the vacuum system present. To address these questions, a series of tracer gas diffusion sampling tests is proposed in which an inert, nontoxic tracer gas, sulfur hexafluoride (SF 6 ), will be injected into a well, and the rates of SF 6 diffusion through the surrounding soil horizon will be measured by sampling in nearby wells. Tracer gas tests will be conducted at sites very near the active vacuum extraction system and also at sites beyond the radius of influence of the active vacuum system. In the passive vapor extraction approach, barometric pressure fluctuations cause soil gas to be drawn to the surface through the well. At the passive sites, the effects of barometric ''pumping'' due to changes in atmospheric pressure will be investigated. Application of tracer gas testing to both the active and passive vapor extraction methods is described in the wellfield enhancement work plan (Rohay and Cameron 1993)

  14. Suitability of tracers; Eignung von Tracern

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-02-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other. [Deutsch] Mit Hilfe der hydrologischen Markierungstechniken koennen Aussagen ueber die Richtung und die Geschwindigkeit von Bewegungen des unterirdischen Wassers gemacht werden. Der einfachere Fall liegt vor, wenn festgestellt werden soll, ob zwischen zwei Punkten eine hydrologische Verbindung besteht. Bei dieser Fliessrichtungsbestimmung sind die Forderungen an die Eigenschaften der einzusetzenden Tracer geringer als bei der Bestimmung der Geschwindigkeit des unterirdischen Wassers. Von den Geschwindigkeiten des unterirdischen Wassers ist die Abstands-(Fliess)geschwindigkeit, die definiert ist durch das Verhaeltnis aus dem Abstand und der wahren Fliesszeit zwischen zwei in Bewegungsrichtung gelegenen Punkten, durch Tracermethoden zu bestimmen. (orig.)

  15. Laplace transform in tracer kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hauser, Eliete B., E-mail: eliete@pucrs.br [Instituto do Cerebro (InsCer/FAMAT/PUC-RS), Porto Alegre, RS, (Brazil). Faculdade de Matematica

    2013-07-01

    The main objective this paper is to quantify the pharmacokinetic processes: absorption, distribution and elimination of radiopharmaceutical(tracer), using Laplace transform method. When the drug is administered intravenously absorption is complete and is available in the bloodstream to be distributed throughout the whole body in all tissues and fluids, and to be eliminated. Mathematical modeling seeks to describe the processes of distribution and elimination through compartments, where distinct pools of tracer (spatial location or chemical state) are assigned to different compartments. A compartment model is described by a system of differential equations, where each equation represents the sum of all the transfer rates to and from a specific compartment. In this work a two-tissue irreversible compartment model is used for description of tracer, [{sup 18}F]2-fluor-2deoxy-D-glucose. In order to determine the parameters of the model, it is necessary to have information about the tracer delivery in the form of an input function representing the time-course of tracer concentration in arterial blood or plasma. We estimate the arterial input function in two stages and apply the Levenberg-Marquardt Method to solve nonlinear regressions. The transport of FDG across de arterial blood is very fast in the first ten minutes and then decreases slowly. We use de Heaviside function to represent this situation and this is the main contribution of this study. We apply the Laplace transform and the analytical solution for two-tissue irreversible compartment model is obtained. The only approach is to determinate de arterial input function. (author)

  16. Internal scanning method as unique imaging method of optical vortex scanning microscope

    Science.gov (United States)

    Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2018-06-01

    The internal scanning method is specific for the optical vortex microscope. It allows to move the vortex point inside the focused vortex beam with nanometer resolution while the whole beam stays in place. Thus the sample illuminated by the focused vortex beam can be scanned just by the vortex point. We show that this method enables high resolution imaging. The paper presents the preliminary experimental results obtained with the first basic image recovery procedure. A prospect of developing more powerful tools for topography recovery with the optical vortex scanning microscope is discussed shortly.

  17. Environmental risk comparisons with internal methods of UST leak detection

    International Nuclear Information System (INIS)

    Durgin, P.B.

    1993-01-01

    The past five years have seen a variety of advances in how leaks can be detected from within underground storage tanks. Any leak-detection approach employed within a storage tanks must be conducted at specific time intervals and meet certain leak-rate criteria according to federal and state regulations. Nevertheless, the potential environmental consequences of leak detection approaches differ widely. Internal, volumetric UST monitoring techniques have developed over time including: (1) inventory control with stick measurements, (2) precision tank testing, (3) automatic tank gauging (ATG), (4) statistical inventory reconciliation (SIR), and (5) statistical techniques with automatic tank gauging. An ATG focuses on the advantage of precise data but measured for only a brief period. On the other hand, stick data has less precision but when combined with SIR over extended periods it too can detect low leak rates. Graphs demonstrate the comparable amounts of fuel than can leak out of a tank before being detected by these techniques. The results indicate that annual tank testing has the greatest potential for large volumes of fuel leaking without detection while new statistical approaches with an ATG have the least potential. The environmental implications of the volumes of fuel leaked prior to detection are site specific. For example, if storage tank is surrounded by a high water table and in a sole-source aquifer even small leaks may cause problems. The user must also consider regulatory risks. The level of environmental and regulatory risk should influence selection of the UST leak detection method

  18. Methods for qualification of highly reliable software - international procedure

    International Nuclear Information System (INIS)

    Kersken, M.

    1997-01-01

    Despite the advantages of computer-assisted safety technology, there still is some uneasyness to be observed with respect to the novel processes, resulting from absence of a body of generally accepted and uncontentious qualification guides (regulatory provisions, standards) for safety evaluation of the computer codes applied. Warranty of adequate protection of the population, operators or plant components is an essential aspect in this context, too - as it is in general with reliability and risk assessment of novel technology - so that, due to appropriate legislation still missing, there currently is a licensing risk involved in the introduction of digital safety systems. Nevertheless, there is some extent of agreement within the international community and utility operators about what standards and measures should be applied for qualification of software of relevance to plant safety. The standard IEC 880/IEC 86/ in particular, in its original version, or national documents based on this standard, are applied in all countries using or planning to install those systems. A novel supplement to this standard, document /IEC 96/, is in the process of finalization and defines the requirements to be met by modern methods of software engineering. (orig./DG) [de

  19. Bitcoin as an Efficient Method for the International Contract Settlement

    Directory of Open Access Journals (Sweden)

    Diachek Olga Yu.

    2017-04-01

    Full Text Available The article is aimed to study the functioning of Bitcoin in today’s world. The issue of the nature of Bitcoin and tendencies in its development have been considered. Given the growing spread of Bitcoin, the number of transactions and the size of the blocks in the system will but increase. In order to maintain correct work, according to progressive growth, consideration is given to the dynamics of the increasing role of the virtual currency, the payment channels through digital coins, and the importance of assimilating such platforms. An analysis of the methods for international contract settlements was carried out. The relevance of implementation of cryptocurrency has been substantiated. The features of functioning of Bitcoin compared to the world currencies were considered. The economic properties of the block chain were studied. In turn, cryptocurrency suggests that the true value of technology lies in its growing potential. In order to develop a complete picture of the effect and scope of Bitcoin, stages of its development and the current status both in Ukraine and the world as a whole were examined. Accordingly, recommendations have been made to improve the status of Bitcoin in Ukraine

  20. Impacts of an Innovative Residential Construction Method on Internal Conditions

    Directory of Open Access Journals (Sweden)

    Roger Birchmore

    2015-02-01

    Full Text Available New Zealand houses are known for producing sub-optimal internal thermal conditions and unacceptably high internal moisture levels. These contribute to poor levels of health, mould and can coincide with the decay of structural timber frames. A proposed solution is to provide an alternative structure utilising plywood, a vapour check on the internal face of the timber frame and an additional air gap, followed by the internal lining. The internal vapour check is designed to prevent moisture vapour diffusion from inside into the frame and to permit moisture diffusion from outside through the structure to the internal environment. Two full scale houses had temperatures, dew points and humidity levels monitored in passive, unoccupied conditions. The test case house incorporated the innovative construction solution. The control house was of identical design and location, using standard construction practice. The calculated internal moisture content profile appeared to be unrelated to the external moisture content as expected, instead following the profile of the changing internal temperature. Whilst the innovative construction appeared to prevent moisture diffusion into the structure in winter and permit it inside in summer, this resulted in a generally higher internal relative humidity than the control house.

  1. The availability of the detection method of internal valve leakage using acoustic method

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Suzuki, Akio

    1989-01-01

    The purpose of this study is to estimate the availability of acoustic method to the internal leakage of the valves at power plants. The acoustic method was applied to the valves at the site, and the background noise was measured for the abnormal plantcondition. From the comparison of the background noise date with the experimental results as to relation between leakage flow and acoust signal, the minimum leakage flow rates that can be detected by the acoust signal was suggested. When the background levels are higher than the acoust signal, the method described below was considered that the analysis the remainder among the background noise frequency spectrum and the acoustic signal spectrum become a very useful leak detection method. A few experimental examples of the spectrum analysis that varied the background noise characteristic were given. (author)

  2. Use of a time-domain electromagnetic method with geochemical tracers to explore the salinity anomalies in a small coastal aquifer in north-eastern Tunisia

    Science.gov (United States)

    Chekirbane, Anis; Tsujimura, Maki; Kawachi, Atsushi; Lachaal, Fethi; Isoda, Hiroko; Tarhouni, Jamila

    2014-12-01

    The study area is a small coastal plain in north-eastern Tunisia. It is drained by an ephemeral stream network and is subject to several pollutant discharges such as oilfield brine coming from a neighboring oil company and wastewater from Somâa city, located in the upstream of the plain. Furthermore, a hydraulic head near the coastal part of the aquifer is below sea level, suggesting that seawater intrusion may occur. A time-domain electromagnetic (TDEM) survey, based on 28 soundings, was conducted in Wadi Al Ayn and Daroufa plains to delineate the saline groundwater. Based on longitudinal and transversal resistivity two-dimensional pseudosections calibrated with boring data, the extent of saline water was identified. Geochemical tracers were combined with the resistivity dataset to differentiate the origin of groundwater salinization. In the upstream part of the plain, the infiltration of oilfield brine through the sandy bed of Wadi Al Ayn seems to have a considerable effect on groundwater salinization. However, in the coastal part of the aquifer, groundwater salinization is due to seawater intrusion and the saltwater is reaching an inland extent around 1.3 km from the shoreline. The contribution ratios of saline water bodies derived from the inverted chloride data vary for the oilfield brine from 1 to 13 % and for the seawater from 2 to 21 %.

  3. Radon diagnostics and tracer gas measurements

    International Nuclear Information System (INIS)

    Jilek, K.; Brabec, M.

    2004-01-01

    An outline is presented of the tracer gas technique, which is used for continuous measurements of air ventilation rate (generally time-varying) and for simultaneous estimation of air ventilation rate and radon entry rate, and some of its limitations are discussed. The performance of this technique in the calculation of the air ventilation rate is demonstrated on real data from routine measurements. The potential for air ventilation rate estimation based on radon measurements only is discussed. A practical application is described of the tracer gas technique to a simultaneous estimation of the air ventilation rate and radon entry rate in a real house where the effectiveness of radon remedy was tested. The following main advantages of the CO tracer gas techniques are stressed: (i) The averaging method continuous determination of the ventilation rate with good accuracy (≤ 20 %). (ii) The newly presented and verified method based on simultaneous measurements of radon concentration and CO gas concentration enables separate continuous measurements of the radon entry rate and ventilation rate. The results of comparative measurements performed with the aim to estimate the inaccuracy in determination of radon entry rate showed acceptable and good agreement up to approximately 10 %. The results of comparative measurements performed with the aim to estimate the mutual commensuration of the method to the determination of the ventilation rate confirmed the expected unreliability the two parametric non-linear regression method, which is the most frequently used method in radon diagnostic in the Czech Republic

  4. Tracer dating and ocean ventilation

    International Nuclear Information System (INIS)

    Thiele, G.; Sarmiento, J.L.

    1990-01-01

    The interpretation of transient tracer observations depends on difficult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. The authors use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. The authors define an idealized ventilation age tracer that is conservative with respect to mixing, and they explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters

  5. Halon-1301, a new Groundwater Age Tracer

    Science.gov (United States)

    Beyer, Monique; van der Raaij, Rob; Morgenstern, Uwe; Jackson, Bethanna

    2015-04-01

    Groundwater dating is an important tool to assess groundwater resources in regards to direction and time scale of groundwater flow and recharge and to assess contamination risks and manage remediation. To infer groundwater age information, a combination of different environmental tracers, such as tritium and SF6, are commonly used. However ambiguous age interpretations are often faced, due to a limited set of available tracers and limitations of each tracer method when applied alone. There is a need for additional, complementary groundwater age tracers. We recently discovered that Halon-1301, a water soluble and entirely anthropogenic gaseous substance, may be a promising candidate [Beyer et al, 2014]. Halon-1301 can be determined along with SF6, SF5CF3 and CFC-12 in groundwater using a gas chromatography setup with attached electron capture detector developed by Busenberg and Plummer [2008]. Halon-1301 has not been assessed in groundwater. This study assesses the behaviour of Halon-1301 in water and its suitability as a groundwater age tracer. We determined Halon-1301 in 17 groundwater and various modern (river) waters sites located in 3 different groundwater systems in the Wellington Region, New Zealand. These waters have been previously dated with tritium, CFC-12, CFC-11 and SF6 with mean residence times ranging from 0.5 to over 100 years. The waters range from oxic to anoxic and some show evidence of CFC contamination or degradation. This allows us to assess the different properties affecting the suitability of Halon-1301 as groundwater age tracer, such as its conservativeness in water and local contamination potential. The samples are analysed for Halon-1301 and SF6simultaneously, which allows identification of issues commonly faced when using gaseous tracers such as contamination with modern air during sampling. Overall we found in the assessed groundwater samples Halon-1301 is a feasible new groundwater tracer. No sample indicated significantly elevated

  6. Meteorological tracers in regional planning

    International Nuclear Information System (INIS)

    Mueller, K.H.

    1974-11-01

    Atmospheric tracers can be used as indicators to study both the ventilation of an urban region and its dispersion meteorology for air pollutants. A correlation analysis applied to the space-time dependent tracer concentrations is able to give transfer functions, the structure and characteristic parameters of which describe the meteorological and topographical situation of the urban region and its surroundings in an integral manner. To reduce the number of persons usually involved in a tracer experiment an automatic air sampling system had to be developed

  7. National Uranium Resource Evaluation. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Final report

    International Nuclear Information System (INIS)

    Chatham, J.R.; Wanty, R.B.; Langmuir, D.

    1981-02-01

    Groundwaters from aquifers in two different sandstone-type uranium mining districts in Texas and Wyoming were collected and chemically analyzed. The data were used to compare the merits of using the computed saturation state of the groundwater with respect to uranium minerals, to that of single-element tracers in the groundwater for geochemical prospecting. Chemical properties of the Texas waters were influenced locally by preferred groundwater flow within buried fluvial channel deposits; upward leakage of brines along growth faults into the aquifer; and the establishment of a redox interface (Eh = 0 volts) within the aquifer. Chemical characteristics of aquifer waters in Wyoming changed gradually downdip, reflecting regional homogeneity in groundwater flow and a more gradual downdip reduction of Eh values than in Texas. The most reliable indicator of reduced uranium ore in both study sites was the saturation state of groundwater with respect to uraninite or coffinite. For both minerals, this saturation state increased from 15 to 20 log units as reduced ore deposits were approached over distances of 3 to 4.5 km in both sites. Tyuyamunite and carnotite approached or exceeded saturation in some oxidized waters of the Texas site reflecting possible occurrences of these minerals. The radiogenic elements Ta and Rn were excellent indicators of ore directly within the deposits, where anomalous values were 2 to 3 orders of magnitude above background. Helium also increased near the ore, although anomalies were generally displaced in the direction of groundwater flow. Uranium and uranium isotope values did not individually pinpoint ore, but may be used together to classify groundwater samples in terms of their position relative to uranium mineralization

  8. Tracer studies with aortic infusion result in improper tracer distribution

    International Nuclear Information System (INIS)

    Wisneski, J.A.; Brooks, G.A.; Neese, R.A.; Stanley, W.C.; Morris, D.L.; Gertz, E.W.

    1986-01-01

    It has been suggested that lactate turnover can be accurately assessed by infusing radioactive lactate tracer into the aorta and sampling blood in the vena cava. However, there may be streaming of newly infused tracer in the aorta, resulting in a nonuniform arterial specific activity (SA). Furthermore vena caval blood may not be representative of mixed venous blood. The authors examined this problem in 7 anesthetized dogs with sampling catheters in the pulmonary (PA), carotid (CA), and femoral (FA) arteries, and the superior (SVC) and inferior (IVC) vena cavi. [1- 14 C]lactate was continuously infused into the left ventricle through a catheter introduced through the femoral artery. The same SA (dpm/μmol) was found in the CA and FA, indicating adequate mixing of newly infused tracer with trace. Three dogs showed differences between SVC, IVC and PA, suggesting a mixed venous sample can not be obtained from the VC. When the catheter was moved into the aorta, wide differences in SA appeared between the CA and FA, clearly reflecting streaming of tracer. These differences also appeared in the SVC and IVC. In conclusion, adequate mixing does not occur between tracer and trace in arterial blood with aortic infusion. Further, VC sampling will not give a consistent mixed venous SA. Therefore, for practical reasons, aortic tracer infusion with vena caval sampling will lead to erroneous turnover values

  9. Tracer technology modeling the flow of fluids

    CERN Document Server

    Levenspiel, Octave

    2012-01-01

    A vessel’s behavior as a heat exchanger, absorber, reactor, or other process unit is dependent upon how fluid flows through the vessel.  In early engineering, the designer would assume either plug flow or mixed flow of the fluid through the vessel.  However, these assumptions were oftentimes inaccurate, sometimes being off by a volume factor of 100 or more.  The result of this unreliable figure produced ineffective products in multiple reaction systems.   Written by a pioneering researcher in the field of chemical engineering, the tracer method was introduced to provide more accurate flow data.  First, the tracer method measured the actual flow of fluid through a vessel.  Second, it developed a suitable model to represent the flow in question.  Such models are used to follow the flow of fluid in chemical reactors and other process units, like in rivers and streams, or solid and porous structures.  In medicine, the tracer method is used to study the flow of chemicals—harmful  and harmless—in the...

  10. Tracer transport in fractured rocks

    International Nuclear Information System (INIS)

    Tsang, C.F.; Tsang, Y.W.; Hale, F.V.

    1988-07-01

    Recent interest in the safety of toxic waste underground disposal and nuclear waste geologic repositories has motivated many studies of tracer transport in fractured media. Fractures occur in most geologic formations and introduce a high degree of heterogeneity. Within each fracture, the aperture is not constant in value but strongly varying. Thus for such media, tracer tends to flow through preferred flowpaths or channels within the fractures. Along each of these channels, the aperture is also strongly varying. A detailed analysis is carried out on a 2D single fracture with variable apertures and the flow through channels is demonstrated. The channels defined this way are not rigidly set pathways for tracer transport, but are the preferred flow paths in the sense of stream-tubes in the potential theory. It is shown that such variable-aperture channels can be characterized by an aperture probability distribution function, and not by the exact deterministic geometric locations. We also demonstrate that the 2D tracer transport in a fracture can be calculated by a model of a system of 1D channels characterized by this distribution function only. Due to the channeling character of tracer transport in fractured rock, random point measurements of tracer breakthrough curves may give results with a wide spread in value due to statistical fluctuations. The present paper suggests that such a wide spread can probably be greatly reduced by making line/areal (or multiple) measurements covering a few spatial correlation lengths. 13 refs., 11 figs., 1 tab

  11. Use of tracers for locating and designing sea outfalls

    International Nuclear Information System (INIS)

    Gauthier, M.; Quetin, B.

    1976-01-01

    Various tracers are used for investigating the propagation of substances in solution or suspension (radioactive, biological, chemical substances and floats). Floats and dyes are the most employed. The main problems associated with the use of such tracers and data interpretation are discussed and it is shown how effective quantitative data can be obtained, especially as regards estimation of turbulent diffusion parameters and identification of suitable dispersion methods for purposes of determining pollutant concentration and areas affected thereby [fr

  12. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  13. Elucidation of hydrogen mobility in tetralin under coal liquefaction conditions using a tritium tracer method. Effects of the addition of H2S and H2O; Tritium tracer ho wo mochiita sekitan ekika hanno jokenka deno tetralin no suiso idosei hyoka. Ryuka suiso oyobi mizu no tenka koka

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, M.; Saito, M.; Ishihara, A.; Kabe, T. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1996-10-28

    It was previously reported that the tritium tracer method is useful for the quantitative consideration of hydrogen behavior in coal during coal liquefaction reaction. Tetralin is excellent hydrogen donating solvent, and is considered as one of the model compounds of coal. In this study, effects of H2S and H2O on the hydrogen exchange reaction between tetralin and gaseous hydrogen labeled by tritium were investigated. It was suggested that the conversion of tetralin and the hydrogen exchange reaction between gaseous hydrogen and tetralin proceed through the radical reaction mechanism with a tetralyl radical as an intermediate product. When H2S existed in this reaction, the hydrogen exchange yield increased drastically without changing the conversion yield. This suggested that the hydrogen exchange reaction proceeds even in the reaction where radical does not give any effect. In the case of H2O addition, the conversion yield and hydrogen exchange rate decreased into a half or one-third. It was suggested that H2O inhibited the formation process of tetralyl radical. 6 refs., 4 figs.

  14. 15N tracer techniques in pediatric research

    International Nuclear Information System (INIS)

    Heine, W.; Richter, I.; Plath, C.; Wutzke, K.; Stolpe, H.J.; Tiess, M.; Toewe, J.

    1983-01-01

    The main topics of the review comprise mathematical fundamentals of the determination of N metabolism parameters using the 3-pool method, the value of different 15 N tracer substances for the determination of whole-body protein parameters, the utilization of parenterally applied D-amino acids, studies on the influence of different diets on the N metabolism of premature infants with the 15 N tracer technique, the application of the 15 N-glycine-STH-test for the evaluation of the therapeutic effect of STH in children suffering from hypothalamico-hypophyseal dwarfism, in vivo studies on urea utilization by the infant intestinal flora under various dietary regimens as well as in vitro investigations on the utilization of 15 N-labelled urea and NH 4 Cl, resp., by the intestinal flora

  15. Natural tracer profiles across argillaceous formations

    International Nuclear Information System (INIS)

    Mazurek, Martin; Alt-Epping, Peter; Bath, Adrian; Gimmi, Thomas; Niklaus Waber, H.; Buschaert, Stephane; Canniere, Pierre De; Craen, Mieke De; Gautschi, Andreas; Savoye, Sebastien; Vinsot, Agnes; Wemaere, Isabelle; Wouters, Laurent

    2011-01-01

    Highlights: → Solute transport processes in clay and shale formations at nine sites are examined. → Conservative pore-water tracers (e.g. Cl - , δ 18 O, δ 2 H, He) show regular profiles. → These indicate the dominance of diffusive transport over times of 10 5 -10 6 years. → The contribution of vertical advection to transport is limited or negligible. → Modelled evolution times are in line with independent palaeo-hydrogeological data. - Abstract: Argillaceous formations generally act as aquitards because of their low hydraulic conductivities. This property, together with the large retention capacity of clays for cationic contaminants, has brought argillaceous formations into focus as potential host rocks for the geological disposal of radioactive and other waste. In several countries, programmes are under way to characterise the detailed transport properties of such formations at depth. In this context, the interpretation of profiles of natural tracers in pore waters across the formations can give valuable information about the large-scale and long-term transport behaviour of these formations. Here, tracer-profile data, obtained by various methods of pore-water extraction for nine sites in central Europe, are compiled. Data at each site comprise some or all of the conservative tracers: anions (Cl - , Br - ), water isotopes (δ 18 O, δ 2 H) and noble gases (mainly He). Based on a careful evaluation of the palaeo-hydrogeological evolution at each site, model scenarios are derived for initial and boundary pore-water compositions and an attempt is made to numerically reproduce the observed tracer distributions in a consistent way for all tracers and sites, using transport parameters derived from laboratory or in situ tests. The comprehensive results from this project have been reported in . Here the results for three sites are presented in detail, but the conclusions are based on model interpretations of the entire data set. In essentially all cases, the

  16. Measurement of open streams by using tracers

    International Nuclear Information System (INIS)

    Ramos, German F.; Tarquino, W.; Curcuy, H.; Orozco, C.

    1999-01-01

    This paper presents an intercomparison study to be carried out between flux measurements by using tracers and moulinet. This intercomparison is scheduled to be performed at the measurement station belonging to the National Service of Meteorology and Hydrology (SENAMHI). Two techniques of tracer dilution are outstanded: total evaluation with tracer punctual injection and punctual evaluation with tracer continuous injection. Total evaluation with tracer punctual injection has been used since this technique is considered to be more suitable for hydrology purposes

  17. A Design Method of Robust Servo Internal Model Control with Control Input Saturation

    OpenAIRE

    山田, 功; 舩見, 洋祐

    2001-01-01

    In the present paper, we examine a design method of robust servo Internal Model Control with control input saturation. First of all, we clarify the condition that Internal Model Control has robust servo characteristics for the system with control input saturation. From this consideration, we propose new design method of Internal Model Control with robust servo characteristics. A numerical example to illustrate the effectiveness of the proposed method is shown.

  18. Internal dosimetry data and methods of ICRP. Part 1

    International Nuclear Information System (INIS)

    Ford, M.R.; Bernard, S.R.; Dillman, L.T.; Watson, S.B.

    1978-01-01

    The methodology being used to update the International Commission on Radiological Protection (ICRP) report of Committee 2, ICRP Publication 2 on Permissible Dose for Internal Radiation, is described. The system of differential equations, which is used to calculate the cumulated activity in the lungs, gastrointestinal tract, other body organs, and the transfer compartment of reference man, is presented. These equations describe the physical decay and metabolism of a radionuclide as governed by the lung and gastrointestinal tract models adopted by Committee 2 from models developed for the ICRP. The equations also take into account organ uptake and retention following intake into blood and the contribution of activity from radioactive daughter nuclides. Additionally, the scheme for estimating the dose from immersion in a radioactive cloud and the scheme for computing the nuclear decay data needed for all of the dose computations are presented. In computing the immersion dose, estimates for both the infinite and the finite cloud are considered

  19. Economic Sustainability in International Business: Peculiarities, Methods and Approaches

    Directory of Open Access Journals (Sweden)

    Otenko Iryna Pavlivna

    2016-05-01

    Full Text Available This article is intended as a contribution to the ongoing analysis of economic sustainability in international business. This study is presented with a view toward further understanding and agreement of the key concepts of sustainability. Approaches to sustainability are considered, important benchmarks and essential characteristics of sustainable development in international business are included. The article demonstrates how the concept of economic sustainability can be applied to the business level. The main ideas of the most widespread concepts on resource management are presented. Incorporation of ESG and financial factors in the concept of sustainable investing is considered. Emissions that are responsible for climate change, namely top emitters, key issues and figures are presented.

  20. Internal quality control of PCR-based genotyping methods

    DEFF Research Database (Denmark)

    Bladbjerg, Else-Marie; Gram, Jørgen; Jespersen, Jørgen

    2002-01-01

    Internal quality control programmes for genetic analyses are needed. We have focused on quality control aspects of selected polymorphism analyses used in thrombosis research. DNA was isolated from EDTA-blood (n = 500) and analysed for 18 polymorphisms by polymerase chain reaction (PCR), i...... because of positive reagent blanks (controls (Control of data handling revealed 0.1% reading mistakes and 0.5% entry mistakes. Based on our experiences, we propose an internal quality control programme......, electrophoresis (analytical factors), result reading and entry into a database (post-analytical factors). Furthermore, we evaluated a procedure for result confirmation. Isolated DNA was of good quality (42 micrograms/ml blood, A260/A280 ratio > 1.75, negative DNAsis tests). Occasionally, results were reanalysed...

  1. Our experience of blood flow measurements using radioactive tracers

    International Nuclear Information System (INIS)

    Danet, Bernard.

    1974-01-01

    A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131 I or sup(99m)Tc, 113 In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers ( 133 Xe, 85 Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed [fr

  2. Systems approach to tracer data in groundwater hydrology

    International Nuclear Information System (INIS)

    Saxena, R.K.

    1977-01-01

    A brief review of current mathematical methods for the analysis of tracer data in groundwater hydrology has been given. The description of the hydrological cycle as a whole or in part, by a system (compartment) or sub-system under linear and stationary conditions is discussed. Basic concepts of transit time, residence time, their distributions in time and response characteristics of a system are outlined. From the knowledge of tracer input, output and systems response function for a generalised system, reservoir capacity and storage for given period can be estimated. Use of a time series model for environmental tracer data in discreet time scale aimed at the solution of hydrological problems e.g. mean transit time and reservoir capacity is also explored. It is concluded that the combination of tracer data with systems approach can go a long way in the study of some complex hydrological problems. (author)

  3. Methods for large-scale international studies on ICT in education

    NARCIS (Netherlands)

    Pelgrum, W.J.; Plomp, T.; Voogt, Joke; Knezek, G.A.

    2008-01-01

    International comparative assessment is a research method applied for describing and analyzing educational processes and outcomes. They are used to ‘describe the status quo’ in educational systems from an international comparative perspective. This chapter reviews different large scale international

  4. The use of tracer techniques to measure water flow rates in steam turbines

    International Nuclear Information System (INIS)

    Whitfield, O.J.; Blaylock, G.; Gale, R.W.

    1979-01-01

    Radioactive and chemical tracers offer some unique advantages in detailed flow measurement on steam turbine plant. A series of experiments on a nuclear power station are reported where tracers successfully measured water flow rates and the initial steam moisture with an accuracy suitable for performance and commissioning tests. Both radioactive and chemical tracer methods produced identical results. Straightforward practical procedures were evolved that ensured repeatable accuracy and in addition a quantitative method of detecting heater leaks on load was established. (author)

  5. Radioactive tracers in the sea

    International Nuclear Information System (INIS)

    Jenkins, W.J.; Livingston, H.D.

    1980-01-01

    Artificial radionuclides introduced to the oceans during the last four decades have proved invaluable tools for study of many processes in marine water columns and sediments. Both global and close-in fallout of radioactivity from atmospheric nuclear weapons testing have distributed these radionuclides widely, and in amounts sufficient to be useful as tracers. An additional source of considerable significance and tracer potential comes from coastal discharges of European nuclear fuel reprocessing wastes. The nature of these sources, types and amounts of radionuclides introduced and the time histories of their introduction generate a variety of tracer distributions which illuminate a broad spectrum of physical and chemical processes active over a wide range of timescales. Depending on their respective chemistries, artificial radionuclides have been demonstrated to exhibit both conservative and non-conservative properties in the oceans. Some examples are given of the uses made of soluble, conservative tracers for the study of oceanic transport processes and of non-conservative tracers for studies of processes which move them to, and mix them within, marine sediments. Sampling and measurement techniques which have been used in these studies are described

  6. International comparison of product certification and verification methods for appliances

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Romankiewicz, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zheng, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-06-01

    Enforcement of appliance standards and consumer trust in appliance labeling are important foundations of growing a more energy efficient economy. Product certification and verification increase compliance rates which in turn increase both energy savings and consumer trust. This paper will serve two purposes: 1) to review international practices for product certification and verification as they relate to the enforcement of standards and labeling programs in the U.S., E.U., Australia, Japan, Canada, and China; and 2) to make recommendations for China to implement improved certification processes related to their mandatory standards and labeling program such as to increase compliance rates and energy savings potential.

  7. International Comparison of Product Certification and Verification Methods for Appliances

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Romankiewicz, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Zheng, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-06-01

    Enforcement of appliance standards and consumer trust in appliance labeling are important foundations of growing a more energy efficient economy. Product certification and verification increase compliance rates which in turn increase both energy savings and consumer trust. This paper will serve two purposes: 1) to review international practices for product certification and verification as they relate to the enforcement of standards and labeling programs in the U.S., E.U., Australia, Japan, Canada, and China; and 2) to make recommendations for China to implement improved certification processes related to their mandatory standards and labeling program such as to increase compliance rates and energy savings potential.

  8. Radiochemical tracers in marine biology

    International Nuclear Information System (INIS)

    Petrocelli, S.R.; Anderson, J.W.; Neff, J.M.

    1977-01-01

    Tracers have been used in a great variety of experimentation. More recently, labeled materials have been applied in marine biological research. Some of the existing tracer techniques have been utilized directly, while others have been modified to suit the specific needs of marine biologists. This chapter describes some of the uses of tracers in marine biological research. It also mentions the problems encountered as well as offering possible solutions and discusses further applications of these techniques. Only pertinent references are cited and additional information may be obtained by consulting these references. Due to their relative ease of maintenance, freshwater species are also utilized in studies which involve radiotracer techniques. Since most of these techniques e directly applicable to marine species, some of these studies will also be included

  9. Corrosion behaviour of stainless steels by internal friction method

    International Nuclear Information System (INIS)

    Postnikov, V.S.; Kovalevskij, V.I.

    1987-01-01

    Corrosion of austenite chromium-nickel stainless steels 12 Kh18N9, 12Kh18N9T, 12Kh18N10 and 12Kh18N10T is investigated. Wire samples 0.7...0.8 mm in diameter before tests were subjected to quenching in water from the temperature of 1050...1100 deg C and part of them - to tempering at 650 deg C for 2 h. Pitting corrosion was brought about by different concentration of iron chloride solutions (C FeCl 3 ). Total corrosion has a slight effect on the character of IF (internal friction) variation that increases without the whole test period up to the moment when mechanical strength of the sample

  10. Compilation and analyses of results from cross-hole tracer tests with conservative tracers

    Energy Technology Data Exchange (ETDEWEB)

    Hjerne, Calle; Nordqvist, Rune; Harrstroem, Johan (Geosigma AB (Sweden))

    2010-09-15

    Radionuclide transport in hydrogeological formations is one of the key factors for the safety analysis of a future repository of nuclear waste. Tracer tests have therefore been an important field method within the SKB investigation programmes at several sites since the late 1970's. This report presents a compilation and analyses of results from cross-hole tracer tests with conservative tracers performed within various SKB investigations. The objectives of the study are to facilitate, improve and reduce uncertainties in predictive tracer modelling and to provide supporting information for SKB's safety assessment of a final repository of nuclear waste. More specifically, the focus of the report is the relationship between the tracer mean residence time and fracture hydraulic parameters, i.e. the relationship between mass balance aperture and fracture transmissivity, hydraulic diffusivity and apparent storativity. For 74 different combinations of pumping and injection section at six different test sites (Studsvik, Stripa, Finnsjoen, Aespoe, Forsmark, Laxemar), estimates of mass balance aperture from cross-hole tracer tests as well as transmissivity were extracted from reports or in the SKB database Sicada. For 28 of these combinations of pumping and injection section, estimates of hydraulic diffusivity and apparent storativity from hydraulic interference tests were also found. An empirical relationship between mass balance aperture and transmissivity was estimated, although some uncertainties for individual data exist. The empirical relationship between mass balance aperture and transmissivity presented in this study deviates considerably from other previously suggested relationships, such as the cubic law and transport aperture as suggested by /Dershowitz and Klise 2002/, /Dershowitz et al. 2002/ and /Dershowitz et al. 2003/, which also is discussed in this report. No clear and direct empirical relationship between mass balance aperture and hydraulic

  11. Development of activable tracers for application in secondary recovering in petroleum reservoirs

    International Nuclear Information System (INIS)

    Martins, Polyana Fabricia Fernandes; Moreira, Rubens Martins . Servico de Meio Ambiente e Tecnicas Nucleares.

    2007-01-01

    Nuclear methods are instrumental in describing detailed flow patterns and other features of oil reservoirs that are unattainable to other methods. Tracer studies in oil fields are performed in a net of injection and producing wells. Thus, the use of only one tracer species would not discriminate the contributions of distinct injection wells to the output of a given production well. Hence, a multi-tracer experiment is required, and the use of activable tracers, capable of being measured by neutron activation analysis (NAA) is here proposed. As additional tracer choices lanthanum (La) and europium (Eu) were chosen from the rare earth series due to their large neutron cross sections and general availability. In order to decrease losses to the oil phase and the retardation of the tracer relatively to the aqueous phase, these elements were complexed with organic chelating ligands: the polyaminocarboxylic acids EDTA, DTPA and DOTA. Infrared spectrometry was used to check complexation. In order to check the partition of the tracer between the aqueous and organic phases, tests were carried stirring the two phases together and measuring the tracer concentrations in the aqueous phase; the partition coefficient (Kao) was then calculated for all the combinations of the two lanthanides and the three ligands. Tests in which the tracer was continuously pumped through reservoir rock samples were also carried out using tritiated water as a reference tracer and the complexed lanthanides. (author)

  12. Quantifying solute transport processes: are chemically "conservative" tracers electrically conservative?

    Science.gov (United States)

    Singha, Kamini; Li, Li; Day-Lewis, Frederick D.; Regberg, Aaron B.

    2012-01-01

    The concept of a nonreactive or conservative tracer, commonly invoked in investigations of solute transport, requires additional study in the context of electrical geophysical monitoring. Tracers that are commonly considered conservative may undergo reactive processes, such as ion exchange, thus changing the aqueous composition of the system. As a result, the measured electrical conductivity may reflect not only solute transport but also reactive processes. We have evaluated the impacts of ion exchange reactions, rate-limited mass transfer, and surface conduction on quantifying tracer mass, mean arrival time, and temporal variance in laboratory-scale column experiments. Numerical examples showed that (1) ion exchange can lead to resistivity-estimated tracer mass, velocity, and dispersivity that may be inaccurate; (2) mass transfer leads to an overestimate in the mobile tracer mass and an underestimate in velocity when using electrical methods; and (3) surface conductance does not notably affect estimated moments when high-concentration tracers are used, although this phenomenon may be important at low concentrations or in sediments with high and/or spatially variable cation-exchange capacity. In all cases, colocated groundwater concentration measurements are of high importance for interpreting geophysical data with respect to the controlling transport processes of interest.

  13. Bootstrap embedding: An internally consistent fragment-based method

    Energy Technology Data Exchange (ETDEWEB)

    Welborn, Matthew; Tsuchimochi, Takashi; Van Voorhis, Troy [Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

    2016-08-21

    Strong correlation poses a difficult problem for electronic structure theory, with computational cost scaling quickly with system size. Fragment embedding is an attractive approach to this problem. By dividing a large complicated system into smaller manageable fragments “embedded” in an approximate description of the rest of the system, we can hope to ameliorate the steep cost of correlated calculations. While appealing, these methods often converge slowly with fragment size because of small errors at the boundary between fragment and bath. We describe a new electronic embedding method, dubbed “Bootstrap Embedding,” a self-consistent wavefunction-in-wavefunction embedding theory that uses overlapping fragments to improve the description of fragment edges. We apply this method to the one dimensional Hubbard model and a translationally asymmetric variant, and find that it performs very well for energies and populations. We find Bootstrap Embedding converges rapidly with embedded fragment size, overcoming the surface-area-to-volume-ratio error typical of many embedding methods. We anticipate that this method may lead to a low-scaling, high accuracy treatment of electron correlation in large molecular systems.

  14. The accurate measurement of the disintegration rate of 55Fe using an internal liquid scintillation counter

    International Nuclear Information System (INIS)

    Botha, S.M.

    1979-01-01

    As the well-known 4πX-γ-coincidence method cannot be used directly to find the disintegration rate of 55 Fe, another method was developed in which a tracer nuclide, possessing coincident gamma radiation, was used. It was now possible to determine the disintegration rate indirectly by the coincidence method using an internal liquid scintillation counter. 54 Mn and 51 Cr which lie in the immediate vicinity of iron in the series of nuclides, are suitable tracers. They are also electron capture nuclides, but decaying to an excited state, were counted by the 4πX-γ-coincidence method. A mixed source, containing 55 Fe and the tracer, was also counted by the coincidence method so that the 4π-counting rate of 55 Fe was obtained as function of the tracer's counting efficiency. It was also essential to find a relationship between the counting efficiencies of the liquid scintillation counter for 55 Fe and the tracer. This relationship is called the effeciency function. Efficiency functions were calculated for 55 Fe and 54 Mn as well as for 55 Fe and 51 Cr. Finally the radioactive concentration of a solution of 55 Fe had been carefully determined by using 54 Mn and 51 Cr tracers. The results for the two different tracers agreed within the statistical uncertainty of 0,4%. The systematic uncertainty on the final results was estimated as 0,17%

  15. International Conference on Robust Rank-Based and Nonparametric Methods

    CERN Document Server

    McKean, Joseph

    2016-01-01

    The contributors to this volume include many of the distinguished researchers in this area. Many of these scholars have collaborated with Joseph McKean to develop underlying theory for these methods, obtain small sample corrections, and develop efficient algorithms for their computation. The papers cover the scope of the area, including robust nonparametric rank-based procedures through Bayesian and big data rank-based analyses. Areas of application include biostatistics and spatial areas. Over the last 30 years, robust rank-based and nonparametric methods have developed considerably. These procedures generalize traditional Wilcoxon-type methods for one- and two-sample location problems. Research into these procedures has culminated in complete analyses for many of the models used in practice including linear, generalized linear, mixed, and nonlinear models. Settings are both multivariate and univariate. With the development of R packages in these areas, computation of these procedures is easily shared with r...

  16. Application of artificial radioactive tracers for groundwater flow

    International Nuclear Information System (INIS)

    Hamza, M.S.; Aly, A.I.M.; Swailem, F.M.; Nada, A.A.; Awad, M.A.

    1989-01-01

    In this work, the groundwater velocity was estimated by applying radioactive tracer techniques: the single well and the multiple well methods. In the first single well method, radioactive iodine-131 was injected in the well and the radioactivity was monitored with time. The groundwater flow was estimated as a function of the concentration dilution factor of the tracer taking into consideration the permeability of the filter screen and the aquifer. The second method (the multiple well technique) is based on direct measuring of the period of time the tracer needs to disperse from the injection well to one of receptor well arranged in a circle around the injection. The latter method was found to be more accurate and reliable and has also the advantage of determining the groundwater velocity and direction of flow as well. The limitations of the single well technique are discussed and a detailed comparison between single and multi-well techniques is given

  17. 77 FR 43827 - International Workshop on Alternative Methods for Leptospira

    Science.gov (United States)

    2012-07-26

    ... recent advances and innovations in science and technology that can be applied to Leptospira vaccine... alternative methods. The workshop is open to the public at no charge with attendance limited only by the... priority. Leptospirosis affects numerous animal species including livestock, pets, and wildlife. Vaccines...

  18. [99mTc]O2-AMD3100 as a SPECT tracer for CXCR4 receptor imaging

    International Nuclear Information System (INIS)

    Hartimath, Siddesh V.; Domanska, Urszula M.; Walenkamp, Annemiek M.E.; Dierckx, Rudi A.J.O.; Vries, Erik F.J. de

    2013-01-01

    Purpose: CXCR4 plays an important role in HIV infection, tumor progression, neurogenesis, and inflammation. In-vivo imaging of CXCR4 could provide more insight in the role of this receptor in health and disease. The aim of this study was to investigate [ 99m Tc]O 2 -AMD3100 as a potential SPECT tracer for imaging of CXCR4. Method: AMD3100 was labelled with [ 99m Tc]pertechnetate. A cysteine challenge assay was performed to test the tracer stability. Heterologous and homologous receptor binding assay and internalization assay were performed in CXCR4 expressing Jurkat-T cells. Ex vivo biodistribution was studied in healthy mice at 30, 60, and 120 min after tracer injection. Tumor uptake of the tracer was determined by microSPECT imaging in nude mice xenografted with human PC-3 prostate tumor. Specificity of tracer uptake was determined by blocking studies using an excess of unlabelled AMD3100. Results: AMD3100 was labelled with technetium-99 m with a radiochemical yield of > 98%. The tracer was stable in PBS and mouse plasma for at least 6 h at 37 °C. Heterologous and homologous binding assays with AMD3100 showed IC 50 values of 240 ± 10 μM, and 92 ± 5 μM for [ 125 I]SDF-1α and [ 99m Tc]O 2 -AMD3100 respectively, with negligible receptor internalisation. The tracer showed high uptake in liver, lungs, spleen, thymus, intestine and bone. Blocking dose of AMD3100.8HCl (20 mg/kg) decreased the uptake in these organs (p 99m Tc]O 2 -AMD3100 showed specific tumor accumulation in mice bearing PC-3 xenografts model. Time activity curves (TAC) in AMD3100 pre-treated animals tracer showed 1.7 times less tumor uptake as compared to control animals (p 99m Tc]O 2 -AMD3100 is readily labelled, is stable in plasma and displays a favourable binding affinity for the CXCR4 receptors. [ 99m Tc O 2 -AMD3100 shows specific binding in organs with high CXCR4 expression and in CXCR4 positive tumors. These results justify further evaluation of this radiopharmaceutical as a potential

  19. Neutron activation analysis method - international ring test for proficiency assessment

    International Nuclear Information System (INIS)

    Barbos, D.; Bucsa, A. F.

    2016-01-01

    The main objective of this test is to assess the quality control of analytical procedures for soils and plants which is of utmost importance to produce reliable and reproducible analytical data. For this purpose first, second, and third line quality control measures are taken in analytical laboratories. For first line control certified reference materials (CRM's) are preferred. However, the number and matrix variation in CRM's for environmental analytical research is still very limited. For second line control internal reference samples are often used, but again here the values for many element and parameter concentrations are questionable since almost no check versus CRM's is possible. For third line control participation in laboratory-evaluating exchange programs is recommended. This article contains the results achieved by our neutron activation analysis laboratory after irradiation experiment of soil and vegetation samples in TRIGA Reactor. All the samples were irradiated in the same location of the reactor in roughly similar conditions. (authors)

  20. Fields Institute International Symposium on Asymptotic Methods in Stochastics

    CERN Document Server

    Kulik, Rafal; Haye, Mohamedou; Szyszkowicz, Barbara; Zhao, Yiqiang

    2015-01-01

    This book contains articles arising from a conference in honour of mathematician-statistician Miklόs Csörgő on the occasion of his 80th birthday, held in Ottawa in July 2012. It comprises research papers and overview articles, which provide a substantial glimpse of the history and state-of-the-art of the field of asymptotic methods in probability and statistics, written by leading experts. The volume consists of twenty articles on topics on limit theorems for self-normalized processes, planar processes, the central limit theorem and laws of large numbers, change-point problems, short and long range dependent time series, applied probability and stochastic processes, and the theory and methods of statistics. It also includes Csörgő’s list of publications during more than 50 years, since 1962.

  1. A consistent and efficient graphical analysis method to improve the quantification of reversible tracer binding in radioligand receptor dynamic PET studies

    OpenAIRE

    Zhou, Yun; Ye, Weiguo; Brašić, James R.; Crabb, Andrew H.; Hilton, John; Wong, Dean F.

    2008-01-01

    The widely used Logan plot in radioligand receptor dynamic PET studies produces marked noise-induced negative biases in the estimates of total distribution volume (DVT) and binding potential (BP). To avoid the inconsistencies in the estimates from the Logan plot, a new graphical analysis method was proposed and characterized in this study. The new plot with plasma input and with reference tissue input was first derived to estimate DVT and BP. A condition was provided to ensure that the estima...

  2. Tracer techniques in karst hydrogeology. Application to the location of karst aquifers

    International Nuclear Information System (INIS)

    Mangin, A.; Molinari, J.

    1976-01-01

    From the recent progress in karst aquifer simulation techniques and the improved knowledge of tracers, the old-established tracer technique has become an invaluable instrument for hydrogeological survey work. Typical information obtainable includes karst system boundaries features and location of hydrodynamic discontinuities, flow variation in both space and time. Tracer methods are a basic requirement for investigation of karst groundwater supplies and determining protection zones for water supply points [fr

  3. Tracers of cancer cells in nuclear oncology

    International Nuclear Information System (INIS)

    Tamgac, F.; Baillet, G.; Moretti, J.L.; Safi, N.; Weinmann, P.; Beco, V. de

    1997-01-01

    Evaluating the extent of disease is important in planning cancer treatment. Different types of tracers are used in vivo to diagnose tumors and these tracers can give supplementary information on the differentiation degree of tumors and response to therapy. (authors)

  4. Tracer techniques in estimating nuclear materials holdup

    International Nuclear Information System (INIS)

    Pillay, K.K.S.

    1987-01-01

    Residual inventory of nuclear materials remaining in processing facilities (holdup) is recognized as an insidious problem for safety of plant operations and safeguarding of special nuclear materials (SNM). This paper reports on an experimental study where a well-known method of radioanalytical chemistry, namely tracer technique, was successfully used to improve nondestructive measurements of holdup of nuclear materials in a variety of plant equipment. Such controlled measurements can improve the sensitivity of measurements of residual inventories of nuclear materials in process equipment by several orders of magnitude and the good quality data obtained lend themselves to developing mathematical models of holdup of SNM during stable plant operations

  5. Risk-oriented internal control: The essence, management methods at small enterprises

    OpenAIRE

    Piskunov, V. A.; Manyayeva, V. A.; Tatarovskaya, T. E.; Bychkova, E. Y.

    2016-01-01

    The research topic relevance is inspired by necessity to develop theoretical and methodical provisions on the internal control system, risk-based management at small enterprises and to prove application feasibility, using economic-mathematical methods its implementation. The purpose of this research is to develop theoretical and methodical approaches to internal control system formation in small businesses, generating reliable and relevant information on the commercial organization activities...

  6. Imaging platelet deposition on Dacron bifurcation grafts in man: Quantification by a dual-tracer method using 111In-labeled platelets and sup(99m)Tc-labeled human serum albumin

    International Nuclear Information System (INIS)

    Isaka, Yoshinari; Kimura, Kazufumi; Etani, Hideki; Uehara, Akira; Yoneda, Shotaro; Kamada, Takenobu; Kusunoki, Masahito; Kim, Teak Dong; Ohshiro, Takeshi

    1986-01-01

    A dual tracer technique using 111 In-labeled platelets and sup(99m)Tc-labeled human serum albumin was applied to evaluate the thrombogenicity of Dacron, bifurcation arterial grafts. The level of platelet accumulation over the whole of the graft was estimated from the ratio of 111 In-platelet radioactivity deposited on the vascular wall to these radioactivity circulating in the blood pool, i.e., the platelet-accumulation index (PAI). Furthermore, the PAI value was calculated for each pixel in digitized images and the PAI distribution image (PAI image) was reconstructed. Eighteen patients with DeBakey knitted Dacron bifurcation grafts and 11 normal volunteers were studied. Of the 18 patients, 11 had no graft occlusion (group I) and the remaining 7 (group II) had occlusion. The mean PAI value (+-SD) over the whole of the graft in group I was 32.6%+-33.7% as compared to -8.8%+-4.5% in the control group (P 2 =10.55; P<0.005). The method used for platelet imaging in the present study may be useful in the study of platelet reactions on Dacron arterial prostheses. (orig.)

  7. Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

    KAUST Repository

    Subramanian, S. K.; Li, Yan; Cathles, L. M.

    2013-01-01

    The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.

  8. Internal and External Dialogue: A Method for Quality Court Management

    Directory of Open Access Journals (Sweden)

    Marie Hagsgård

    2008-10-01

    Full Text Available The aim of quality court work is to maintain or improve public trust in the court as a vital part of a democratic society. Public confidence in the judicial system is affected by a number of factors, including speedy and judicially correct decisions which are generally understandable and a good treatment of parties and witnesses before and during court proceedings. In order to uphold and enhance public trust, courts need to work systematically to improve the quality of court functioning. But questions remain regarding how to institute quality court management, and how to achieve positive results. Although court managers in Sweden have shown an interest in starting systematic quality work, they have found it difficult to find a method for such work and systematically achieving results.

  9. Comparison of two synthetic methods to obtain [18F] N-(2-aminoethyl)-5-fluoropyridine-2-carboxamide, a potential MAO-B imaging tracer for PET

    International Nuclear Information System (INIS)

    Beer, H.-F.; Haeberli, M.; Ametamey, S.; Schubiger, P.A.

    1995-01-01

    The compound Ro 19-6327, N-(2-aminoethyl)-5-chloropyridine-2-carboxamide, is known to inhibit reversibly and site specifically the enzyme monoamine oxidase B (MAO-B). The 123 I-labelled iodo-analogue N-(2-aminoethyl)-5-iodopyridine-2-carboxamide (Ro 43-0463) was investigated successfully in human volunteers by means of SPET (Single Photon Emission Tomography). We developed therefore the synthesis and radiolabelling of the corresponding fluoro-analogue N-(2-aminoethyl)-5-fluoropyridine-2-carboxamide with 18 F in order to carry out PET (Positron Emission Tomography) investigations of MAO-B related neuropsychiatric diseases. For this purpose two synthetic approaches leading to the electrophilic and the nucleophilic methods of 18 F radiolabelling were undertaken. The nucleophilic approach appeared to be superior when factors such as precursor synthesis, beam time, specific activity and radiochemical purity of the product are considered. (author)

  10. A TRACER METHOD FOR COMPUTING TYPE IA SUPERNOVA YIELDS: BURNING MODEL CALIBRATION, RECONSTRUCTION OF THICKENED FLAMES, AND VERIFICATION FOR PLANAR DETONATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Townsley, Dean M.; Miles, Broxton J. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL (United States); Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Calder, Alan C. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY (United States); Brown, Edward F., E-mail: Dean.M.Townsley@ua.edu [The Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI (United States)

    2016-07-01

    We refine our previously introduced parameterized model for explosive carbon–oxygen fusion during thermonuclear Type Ia supernovae (SNe Ia) by adding corrections to post-processing of recorded Lagrangian fluid-element histories to obtain more accurate isotopic yields. Deflagration and detonation products are verified for propagation in a medium of uniform density. A new method is introduced for reconstructing the temperature–density history within the artificially thick model deflagration front. We obtain better than 5% consistency between the electron capture computed by the burning model and yields from post-processing. For detonations, we compare to a benchmark calculation of the structure of driven steady-state planar detonations performed with a large nuclear reaction network and error-controlled integration. We verify that, for steady-state planar detonations down to a density of 5 × 10{sup 6} g cm{sup −3}, our post-processing matches the major abundances in the benchmark solution typically to better than 10% for times greater than 0.01 s after the passage of the shock front. As a test case to demonstrate the method, presented here with post-processing for the first time, we perform a two-dimensional simulation of a SN Ia in the scenario of a Chandrasekhar-mass deflagration–detonation transition (DDT). We find that reconstruction of deflagration tracks leads to slightly more complete silicon burning than without reconstruction. The resulting abundance structure of the ejecta is consistent with inferences from spectroscopic studies of observed SNe Ia. We confirm the absence of a central region of stable Fe-group material for the multi-dimensional DDT scenario. Detailed isotopic yields are tabulated and change only modestly when using deflagration reconstruction.

  11. Energy demand forecasting method based on international statistical data

    International Nuclear Information System (INIS)

    Glanc, Z.; Kerner, A.

    1997-01-01

    Poland is in a transition phase from a centrally planned to a market economy; data collected under former economic conditions do not reflect a market economy. Final energy demand forecasts are based on the assumption that the economic transformation in Poland will gradually lead the Polish economy, technologies and modes of energy use, to the same conditions as mature market economy countries. The starting point has a significant influence on the future energy demand and supply structure: final energy consumption per capita in 1992 was almost half the average of OECD countries; energy intensity, based on Purchasing Power Parities (PPP) and referred to GDP, is more than 3 times higher in Poland. A method of final energy demand forecasting based on regression analysis is described in this paper. The input data are: output of macroeconomic and population growth forecast; time series 1970-1992 of OECD countries concerning both macroeconomic characteristics and energy consumption; and energy balance of Poland for the base year of the forecast horizon. (author). 1 ref., 19 figs, 4 tabs

  12. On theTranslation Methods and Theory of International Advertising

    Institute of Scientific and Technical Information of China (English)

    Yang Xuemei

    2012-01-01

    Advertisement, as a way to propagandize products, always plays its role in the special stage. A successful advertisement would help the manufacturer to achieve a large sale while an unsuccessful even a bad one would do the contrast work. Advertising is an activity containing intelligence, patience, art and diligence. With the globalization and China' s entering WT0, more and more Chinese products get the opportunity of entering world market. In this battle without smoke of gun powder, the most powerful weapon is commercial advertisement. Therefore, advertisement becomes more important. At the same time, the translation of advertising plays its role as to internationalize advertisement to the world. It seems as a bridge overpass different countries and languages. However, due to the difference among cultures, problems appear how to be a good advertising translator and how to make an excellent translation of advertising. This thesis tries to analyses the criteria and strategies of advertising translation after the discussion of the types, structure and features of style of advertisements and states that there is no an established method for advertising translation. What we should do is to be flexible to deal with the various advertisements we meet.

  13. Energy demand forecasting method based on international statistical data

    Energy Technology Data Exchange (ETDEWEB)

    Glanc, Z; Kerner, A [Energy Information Centre, Warsaw (Poland)

    1997-09-01

    Poland is in a transition phase from a centrally planned to a market economy; data collected under former economic conditions do not reflect a market economy. Final energy demand forecasts are based on the assumption that the economic transformation in Poland will gradually lead the Polish economy, technologies and modes of energy use, to the same conditions as mature market economy countries. The starting point has a significant influence on the future energy demand and supply structure: final energy consumption per capita in 1992 was almost half the average of OECD countries; energy intensity, based on Purchasing Power Parities (PPP) and referred to GDP, is more than 3 times higher in Poland. A method of final energy demand forecasting based on regression analysis is described in this paper. The input data are: output of macroeconomic and population growth forecast; time series 1970-1992 of OECD countries concerning both macroeconomic characteristics and energy consumption; and energy balance of Poland for the base year of the forecast horizon. (author). 1 ref., 19 figs, 4 tabs.

  14. MESYST, Simulation of 3-D Tracer Dispersion in Atmosphere

    International Nuclear Information System (INIS)

    Mastrangelo, V.; Mehilli, I.

    2000-01-01

    1 - Description of program or function: Mesyst code is used for the simulation of 3D tracer dispersion in atmosphere. Three packages are part of this system: Cre-topo: prepares the terrain data for the Mesyst. Noabl: code calculates three- dimensional free divergence wind fields over complex terrain. Pas: Computing of tracer concentrations and depositions on a given domain. 2 - Method of solution: NOABL - Line Over Relaxation + Special adaptation of Gauss procedure. PAS - Monte Carlo Method. 3 - Restrictions on the complexity of the problem: Computations: Mesh size: variable from some meters to some hundreds meters Mesh number: variable depending on available real data (some hundreds points on each directions)

  15. Tracer techniques for determination of groundwater flow parameters

    International Nuclear Information System (INIS)

    Drost, W.; Klotz, D.

    1988-05-01

    The most common one-borehole and multiple borehole methods using tracers for the direct determination of the groundwater flow parameters (velocity of flow, flow direction) and for the indirect determination of characteristic quantities of the aquifer (effective porosity, dispersivity, transmissivity) are presented methodically and their value is documented by practical examples. Especially, the properties of and measuring technique with suitable tracers are considered (e.g. T, Na-24, Cr-51, Co-58, Co-60, Br-82, Tc-99, I-125, I-131, Au-198). (orig./HP) [de

  16. A model for C-14 tracer evaporative rate analysis (ERA)

    International Nuclear Information System (INIS)

    Gardner, R.P.; Verghese, K.

    1993-01-01

    A simple model has been derived and tested for the C-14 tracer evaporative rate analysis (ERA) method. It allows the accurate determination of the evaporative rate coefficient of the C-14 tracer detector in the presence of variable evaporation rates of the detector solvent and variable background counting rates. The evaporation rate coefficient should be the most fundamental parameter available in this analysis method and, therefore, its measurements with the proposed model should allow the most direct correlations to be made with the system properties of interest such as surface cleanliness. (author)

  17. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    International Nuclear Information System (INIS)

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging

  18. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.

  19. Tracer-tracer relations as a tool for research on polar ozone loss

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rolf

    2010-07-01

    The report includes the following chapters: (1) Introduction: ozone in the atmosphere, anthropogenic influence on the ozone layer, polar stratospheric ozone loss; (2) Tracer-tracer relations in the stratosphere: tracer-tracer relations as a tool in atmospheric research; impact of cosmic-ray-induced heterogeneous chemistry on polar ozone; (3) quantifying polar ozone loss from ozone-tracer relations: principles of tracer-tracer correlation techniques; reference ozone-tracer relations in the early polar vortex; impact of mixing on ozone-tracer relations in the polar vortex; impact of mesospheric intrusions on ozone-tracer relations in the stratospheric polar vortex calculation of chemical ozone loss in the arctic in March 2003 based on ILAS-II measurements; (4) epilogue.

  20. New SPECT tracers: Example of tracers of proteoglycans and melanin

    International Nuclear Information System (INIS)

    Cachin, F.; Mestas, D.; Kelly, A.; Merlin, C.; Veyre, A.; Maublant, J.; Cachin, F.; Chezal, J.M.; Miot-Noirault, E.; Moins, N.; Auzeloux, P.; Vidal, A.; Bonnet-Duquennoy, M.; Boisgard, S.; D'Incan, M.; Madelmont, J.C.; Maublant, J.; Boisgard, S.; D'Incan, M.; Redini, F.; Filaire, M.

    2009-01-01

    The majority of research program on new radiopharmaceuticals turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The 99m Tc-N.T.P. 15-5 (N.T.P. 15-5 for N-[tri-ethyl-ammonium]-3-propyl-[15]ane-N5) which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodo benzamides, specific to the melanin, are nowadays compared to 18 F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on N-[2-(diethyl-amino)ethyl]-4 and 2-iodo benzamides respectively B.Z.A. and B.Z.A.2 hetero-aromatic analogues usable for melanoma treatment. (authors)

  1. A method to measure internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures

    Science.gov (United States)

    Tian, Qijie; Chang, Songtao; Li, Zhou; He, Fengyun; Qiao, Yanfeng

    2017-03-01

    The suppression level of internal stray radiation is a key criterion for infrared imaging systems, especially for high-precision cryogenic infrared imaging systems. To achieve accurate measurement for internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures, a measurement method, which is based on radiometric calibration, is presented in this paper. First of all, the calibration formula is deduced considering the integration time, and the effect of ambient temperature on internal stray radiation is further analyzed in detail. Then, an approach is proposed to measure the internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures. By calibrating the system under two ambient temperatures, the quantitative relation between the internal stray radiation and the ambient temperature can be acquired, and then the internal stray radiation of the cryogenic infrared imaging system under various ambient temperatures can be calculated. Finally, several experiments are performed in a chamber with controllable inside temperatures to evaluate the effectiveness of the proposed method. Experimental results indicate that the proposed method can be used to measure internal stray radiation with high accuracy at various ambient temperatures and integration times. The proposed method has some advantages, such as simple implementation and the capability of high-precision measurement. The measurement results can be used to guide the stray radiation suppression and to test whether the internal stray radiation suppression performance meets the requirement or not.

  2. International manufacturing and logistics: application of a design method in five case studies

    NARCIS (Netherlands)

    Vos, G.C.J.M.

    1993-01-01

    International manufacturing and logistics has become an important topic for an increasing number of industrial firms. In this paper, a design method will be described which is aimed at supporting managers in decisions regarding the (re)design of international logistic structures. The heart of this

  3. On-line measurements of liquid carry-over from scrubbers using radioactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Haugan, A; Hassfjell, S [Institute for Energy Technology, Kjeller (Norway); Finborud, A [Mator, Porsgrunn (Norway)

    2004-07-01

    A method to measure liquid carry-over from scrubbers using gamma-emitting tracers is described and results from field tests at two onshore installations are presented. One water/1,2-ethanediol (MEG) and two hydrocarbon liquid (condensate) tracers have been used in the tests. One of the condensate tracers deposited to some extent inside the process pipe, while the other had a too high vapor pressure. The water/MEG tracer showed no MEG carry-over while the carry-over of MEG was documented to be considerable. (author)

  4. On-line measurements of liquid carry-over from scrubbers using radioactive tracers

    International Nuclear Information System (INIS)

    Haugan, A.; Hassfjell, S.; Finborud, A.

    2004-01-01

    A method to measure liquid carry-over from scrubbers using gamma-emitting tracers is described and results from field tests at two onshore installations are presented. One water/1,2-ethanediol (MEG) and two hydrocarbon liquid (condensate) tracers have been used in the tests. One of the condensate tracers deposited to some extent inside the process pipe, while the other had a too high vapor pressure. The water/MEG tracer showed no MEG carry-over while the carry-over of MEG was documented to be considerable. (author)

  5. Tracer technique for measuring specific activity of 63 Ni, using 4πβ-γ

    International Nuclear Information System (INIS)

    Iwahara, A.

    1979-01-01

    The specific activity of a 6 3 Ni solution has been measured by an efficiency tracer technique using a 4 π β - γ coincidence system. 6 3 Ni was chosen. Because it's a very low energy pure beta emitter. Due to chemical compatibility and beta spectral shapes, 6 0 Co has been chosen as tracer. In the determination of 6 3 Ni, the specific activity. As the efficiency tracer techniques requires a previous knowledge of tracer activity, this has been measured by a conventional 4 π β -γ coincidence method. (author)

  6. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  7. Use of radioactive tracers in chemical reactions

    International Nuclear Information System (INIS)

    Paci, B.; Saiki, M.

    1979-01-01

    A method for the determination of small quantities of nickel by using radioactive tracers is presented. An analytical application of the displacement reaction between and zinc-ethylenediaminetetraacetate, (Zn-EDTA), labelled with 65 Zn is investigated. This method is based on the extraction of radioactive zinc, displaced by nickel from the zinc chelate, into a dithizone-carbon tetrachloride solution and the subsequent measurement of the activity of an aliquot of the extract. It is shown that the method is very sentitive and nickel can be measured in concentrations as small as 0,1μg/ml or even less, depending on the specific activity of the radioreagent used. The precision and accuracy of the method are determined. An attempt to eliminate the problem of interference by using masking agents or by means of a previous separation of nickel and other interfereing metals, is also made. (Author) [pt

  8. Use of radioactive tracers in chemical reactions

    International Nuclear Information System (INIS)

    Paci, B.

    1979-01-01

    A method for the determination of small quantities of nickel using radioactive tracers is presented. An analytical application of the displacement reaction between nickel and zinc ethylenediaminetetraacetate labeled with zinc-65 is pursued. This method is based on the extraction of radioactive zinc displaced by nickel from the zinc chelate into a dithizone-carbon tetracloride solution and the subsequent measurement of the activity of an aliquot of the extract. The method is very sensitive and nickel can be measured in concentrations as small as 0.1μg/ml or even less, depending on the specific activity of the radioreagent used. The precision and the accuracy of the method are determined. The problem of interferences, trying to eliminate them by using masking agents or by means of a previous separation between nickel and other interfering metals, is also investigated [pt

  9. Fifty years of radiochemical tracers

    International Nuclear Information System (INIS)

    Evans, E.A.

    1992-01-01

    During the past 50 years radiochemical tracers, usually in the form of isotopically labelled organic compounds, have been essential tools to further advance our knowledge at the frontiers of a great variety of scientific developments in the life sciences. This plenary lecture reviews necessarily selected highlights in the synthesis and applications of such radiochemical tracers. Included are examples where important advances, made possible by using radiochemicals, have contributed to improving the quality of life on this planet. The principal radioisotopes involved, 14 C, 3 H, 35 S, 32 P, 125 I, are all relatively safe to handle and are commercially available at maximum theoretical specific activity (carrier free). The compounds labeled with these radioisotopes are used in many fields of research which include biosynthesis and biotechnology studies, cell biology, drug metabolism, clinical research and environmental applications, and are briefly reviewed. (author). 55 refs

  10. Development of some new Aza and Thia complex as alternative tracers for oil reservoirs

    International Nuclear Information System (INIS)

    Silva, Lauris L.; Donnici, Claudio L.; Ayala, Jose D.

    2009-01-01

    A promising group of non-sorbing tracers are lanthanide ions complexed to organic anions, which yield a negatively charged complex. Besides, this lanthanide ion could be chosen which, in its non-complexed form, is very insoluble in groundwater and thus no severe background concentrations problem would arise. The lanthanide elements may be used as tracers since they present good solubility in water, when complexed, and the nuclides have high neutron cross sections, they may be used as activable tracers under neutron irradiation in order to evaluate the efficiency of the petroleum production processes. For this purpose, tracers must be soluble in the aqueous phase and be insoluble in the organic phase, they also must not be adsorbed on the internal microporous rock formations and be easily detectable. Lanthanide complexes with DTPA and thiodicarboxylic acid ligands are an alternative to the development of these novel tracers since their properties may be chemically adjusted. (author)

  11. A method to measure internal contact angle in opaque systems by magnetic resonance imaging.

    Science.gov (United States)

    Zhu, Weiqin; Tian, Ye; Gao, Xuefeng; Jiang, Lei

    2013-07-23

    Internal contact angle is an important parameter for internal wettability characterization. However, due to the limitation of optical imaging, methods available for contact angle measurement are only suitable for transparent or open systems. For most of the practical situations that require contact angle measurement in opaque or enclosed systems, the traditional methods are not effective. Based upon the requirement, a method suitable for contact angle measurement in nontransparent systems is developed by employing MRI technology. In the Article, the method is demonstrated by measuring internal contact angles in opaque cylindrical tubes. It proves that the method also shows great feasibility in transparent situations and opaque capillary systems. By using the method, contact angle in opaque systems could be measured successfully, which is significant in understanding the wetting behaviors in nontransparent systems and calculating interfacial parameters in enclosed systems.

  12. The Accurate Particle Tracer Code

    OpenAIRE

    Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi

    2016-01-01

    The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and non-linear problems. Under the well-designed integrated and modularized framework, APT serves as a universal platform for researchers from different fields, such as plasma physics, accelerator physics, space science, fusio...

  13. The Diagnosis of Internal Leakage of Control Valve Based on the Grey Correlation Analysis Method

    Directory of Open Access Journals (Sweden)

    Zheng DING

    2014-07-01

    Full Text Available The valve plays an important part in the industrial automation system. Whether it operates normally or not relates with the quality of the products directly while its faults are relatively common because of bad working conditions. And the internal leakage is one of the common faults. Consequently, this paper sets up the experimental platform to make the valve in different working condition and collect relevant data online. Then, diagnose the internal leakage of the valve by using the grey correlation analysis method. The results show that this method can not only diagnose the internal leakage of valve accurately, but also distinguish fault degree quantitatively.

  14. Complex functionality with minimal computation: Promise and pitfalls of reduced-tracer ocean biogeochemistry models

    Science.gov (United States)

    Galbraith, Eric D.; Dunne, John P.; Gnanadesikan, Anand; Slater, Richard D.; Sarmiento, Jorge L.; Dufour, Carolina O.; de Souza, Gregory F.; Bianchi, Daniele; Claret, Mariona; Rodgers, Keith B.; Marvasti, Seyedehsafoura Sedigh

    2015-12-01

    Earth System Models increasingly include ocean biogeochemistry models in order to predict changes in ocean carbon storage, hypoxia, and biological productivity under climate change. However, state-of-the-art ocean biogeochemical models include many advected tracers, that significantly increase the computational resources required, forcing a trade-off with spatial resolution. Here, we compare a state-of-the art model with 30 prognostic tracers (TOPAZ) with two reduced-tracer models, one with 6 tracers (BLING), and the other with 3 tracers (miniBLING). The reduced-tracer models employ parameterized, implicit biological functions, which nonetheless capture many of the most important processes resolved by TOPAZ. All three are embedded in the same coupled climate model. Despite the large difference in tracer number, the absence of tracers for living organic matter is shown to have a minimal impact on the transport of nutrient elements, and the three models produce similar mean annual preindustrial distributions of macronutrients, oxygen, and carbon. Significant differences do exist among the models, in particular the seasonal cycle of biomass and export production, but it does not appear that these are necessary consequences of the reduced tracer number. With increasing CO2, changes in dissolved oxygen and anthropogenic carbon uptake are very similar across the different models. Thus, while the reduced-tracer models do not explicitly resolve the diversity and internal dynamics of marine ecosystems, we demonstrate that such models are applicable to a broad suite of major biogeochemical concerns, including anthropogenic change. These results are very promising for the further development and application of reduced-tracer biogeochemical models that incorporate "sub-ecosystem-scale" parameterizations.

  15. Predicting the diversity of internal temperatures from the English residential sector using panel methods

    International Nuclear Information System (INIS)

    Kelly, Scott; Shipworth, Michelle; Shipworth, David; Gentry, Michael; Wright, Andrew; Pollitt, Michael; Crawford-Brown, Doug; Lomas, Kevin

    2013-01-01

    Highlights: ► A new method is proposed incorporating behavioural, environmental and building efficiency variables to explain internal dwelling temperatures. ► It is the first time panel methods have been used to predict internal dwelling temperatures over time. ► The proposed method is able to explain 45% of the variance of internal temperature between heterogeneous dwellings. ► Results support qualitative research on the importance of social, cultural and psychological behaviour in determining internal dwelling temperatures. behaviour. ► This method presents new opportunities to quantify the size of the direct rebound effect between heterogeneous dwellings. -- Abstract: In this paper, panel methods are applied in new and innovative ways to predict daily mean internal temperature demand across a heterogeneous domestic building stock over time. This research not only exploits a rich new dataset but presents new methodological insights and offers important linkages for connecting bottom-up building stock models to human behaviour. It represents the first time a panel model has been used to estimate the dynamics of internal temperature demand from the natural daily fluctuations of external temperature combined with important behavioural, socio-demographic and building efficiency variables. The model is able to predict internal temperatures across a heterogeneous building stock to within ∼0.71 °C at 95% confidence and explain 45% of the variance of internal temperature between dwellings. The model confirms hypothesis from sociology and psychology that habitual behaviours are important drivers of home energy consumption. In addition, the model offers the possibility to quantify take-back (direct rebound effect) owing to increased internal temperatures from the installation of energy efficiency measures. The presence of thermostats or thermostatic radiator valves (TRVs) are shown to reduce average internal temperatures, however, the use of an automatic timer

  16. Development of radioisotope tracer technology and nucleonic control system

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee and others

    1999-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and basic technology of nuclear control systems that are widely used for automation of industrial plants, and to build a strong tracer group to support the local industries. In relation to the tracer technology, the data acquisition system, the column scanning equipment and the detection pig for a leakage test have been developed. In order to use in analyzing data of tracer experiments, a computer program for the analysis of residence time distribution has been created as well. These results were utilized in developing the tracer technologies, such as the column scanning, the flow measurement using the dilution method, the simultaneous monitoring rotational movement of piston rings and the optimization of a waste water treatment facility, and the technologies were successfully demonstrated in the local industrial. The stripper of RFCC reactor has been examined to find an unwanted structure in it by imminent request from the industry. Related to the development of nucleonic control system, the state of art report on the technology has been written and an equipment for the analysis of asphalt content has been developed. (author)

  17. TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data

    Science.gov (United States)

    Jurgens, Bryant C.; Böhlke, J.K.; Eberts, Sandra M.

    2012-01-01

    TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of hydrodynamic dispersion or mixing within the aquifer, well bore, or discharge area. Five primary LPMs are included in the workbook: piston-flow model (PFM), exponential mixing model (EMM), exponential piston-flow model (EPM), partial exponential model (PEM), and dispersion model (DM). Binary mixing models (BMM) can be created by combining primary LPMs in various combinations. Travel time through the unsaturated zone can be included as an additional parameter. TracerLPM also allows users to enter age distributions determined from other methods, such as particle tracking results from numerical groundwater-flow models or from other LPMs not included in this program. Tracers of both young groundwater (anthropogenic atmospheric gases and isotopic substances indicating post-1940s recharge) and much older groundwater (carbon-14 and helium-4) can be interpreted simultaneously so that estimates of the groundwater age distribution for samples with a wide range of ages can be constrained. TracerLPM is organized to permit a comprehensive interpretive approach consisting of hydrogeologic conceptualization, visual examination of data and models, and best-fit parameter estimation. Groundwater age distributions can be evaluated by comparing measured and modeled tracer concentrations in two ways: (1) multiple tracers analyzed simultaneously can be evaluated against each other for concordance with modeled concentrations (tracer-tracer application) or (2) tracer time-series data can be evaluated for concordance with modeled trends (tracer-time application). Groundwater-age estimates can also be obtained for samples with a single tracer measurement at one

  18. Determination of dispersion coefficients and average flow velocities in rivers radioactive tracers

    International Nuclear Information System (INIS)

    Carvalho, M.A.G. de; Moreira, R.M.

    1984-01-01

    The determination of the dispersion characteristics and residence time distribution in a series of adjoining stretches of a river with one single tracer injection, are presented. The method allows minimizing the amount of work and tracer expenditure in the measurement of fluvial transport over long or heterogeneous river courses. (M.A.C.) [pt

  19. Use of radioactive tracers in the semiconductor industry

    International Nuclear Information System (INIS)

    Akerman, Karol

    1975-01-01

    Manufacture of the semiconductor materials comprises production and purification of the raw materials (GeC14 or SiHC13), purification of the elemental semiconductors by metallurgical methods (including zone melting), production and doping of single crystals, dividing the crystals into slices of suitable size, formation of p-n junctions and fabrication of the finished semiconductor devices. In the sequence of operations, the behavior of very small quantities of an element must be monitored, and radioactive tracers are often used to solve these problems. Examples are given of the use of radioactive tracers in the semiconductor industry

  20. Holdup time measurement by radioactive tracers in pulp production

    International Nuclear Information System (INIS)

    Roetzer, H.; Donhoffer, D.

    1988-12-01

    A batch of pulp was to be labelled before passing two bleaching towers of a pulp plant. Activated glass fibres were used as a tracer, which contained 24-Na with a half-life of 15 hours. It was shown in laboratory tests, that the glass fibres were suitable for transport studies of wood pulp. For use in the tests the fibres were activated and suspended in water. Due to the small diameter of the fibres (2-5 micrometers) this suspension shows physical properties very similar to the pulp. For detection six scintillation probes were mounted at different positions outside the bleaching tower. Radiation protection during the test was very easy due to the low total activity of the tracer material. Residence time distributions for both towers were measured. The successful tracer experiments show, that the method of labelling is suited for investigations of material transport in the pulp and paper industry. 3 figs., 11 refs., 2 tabs. (Author)

  1. Randomized controlled trial of internal and external targeted temperature management methods in post- cardiac arrest patients.

    Science.gov (United States)

    Look, Xinqi; Li, Huihua; Ng, Mingwei; Lim, Eric Tien Siang; Pothiawala, Sohil; Tan, Kenneth Boon Kiat; Sewa, Duu Wen; Shahidah, Nur; Pek, Pin Pin; Ong, Marcus Eng Hock

    2018-01-01

    Targeted temperature management post-cardiac arrest is currently implemented using various methods, broadly categorized as internal and external. This study aimed to evaluate survival-to-hospital discharge and neurological outcomes (Glasgow-Pittsburgh Score) of post-cardiac arrest patients undergoing internal cooling verses external cooling. A randomized controlled trial of post-resuscitation cardiac arrest patients was conducted from October 2008-September 2014. Patients were randomized to either internal or external cooling methods. Historical controls were selected matched by age and gender. Analysis using SPSS version 21.0 presented descriptive statistics and frequencies while univariate logistic regression was done using R 3.1.3. 23 patients were randomized to internal cooling and 22 patients to external cooling and 42 matched controls were selected. No significant difference was seen between internal and external cooling in terms of survival, neurological outcomes and complications. However in the internal cooling arm, there was lower risk of developing overcooling (p=0.01) and rebound hyperthermia (p=0.02). Compared to normothermia, internal cooling had higher survival (OR=3.36, 95% CI=(1.130, 10.412), and lower risk of developing cardiac arrhythmias (OR=0.18, 95% CI=(0.04, 0.63)). Subgroup analysis showed those with cardiac cause of arrest (OR=4.29, 95% CI=(1.26, 15.80)) and sustained ROSC (OR=5.50, 95% CI=(1.64, 20.39)) had better survival with internal cooling compared to normothermia. Cooling curves showed tighter temperature control for internal compared to external cooling. Internal cooling showed tighter temperature control compared to external cooling. Internal cooling can potentially provide better survival-to-hospital discharge outcomes and reduce cardiac arrhythmia complications in carefully selected patients as compared to normothermia. Copyright © 2017. Published by Elsevier Inc.

  2. A comparison of possibilities of using methods of internal corporate education - coaching and mentoring

    OpenAIRE

    Kolmistrová, Aneta

    2013-01-01

    This thesis examines the application of two educational methods - coaching and mentoring - in an internal corporate education system. Attention is first drawn to the concept of corporate education, while terms such as education effectiveness and procedures of actual implementation are clarified. Thereafter, both examined methods are defined and goals to achieve through these methods are presented. Both methods are then compared, with the emphasis on their similarities and differences. The the...

  3. Calorimetric Measurement for Internal Conversion Efficiency of Photovoltaic Cells/Modules Based on Electrical Substitution Method

    Science.gov (United States)

    Saito, Terubumi; Tatsuta, Muneaki; Abe, Yamato; Takesawa, Minato

    2018-02-01

    We have succeeded in the direct measurement for solar cell/module internal conversion efficiency based on a calorimetric method or electrical substitution method by which the absorbed radiant power is determined by replacing the heat absorbed in the cell/module with the electrical power. The technique is advantageous in that the reflectance and transmittance measurements, which are required in the conventional methods, are not necessary. Also, the internal quantum efficiency can be derived from conversion efficiencies by using the average photon energy. Agreements of the measured data with the values estimated from the nominal values support the validity of this technique.

  4. Theory building trends in international management research: an archival review of preferred methods

    Directory of Open Access Journals (Sweden)

    Drikus Kriek

    2011-08-01

    Full Text Available A number of distinguished scholars believe that for theory development to occur within a field, qualitative research must precede quantitative research in order for the field to progress toward maturity. The purpose of this study was to investigate the international management literature from 1991-2007 to ascertain current levels of use of qualitative, quantitative, conceptual and joint (quantitative and qualitative research methods in the field.  Results indicate scholars employ quantitative methods more than qualitative methods.  The implications of these findings for future theory development and the generation of context relevant international management knowledge are discussed.

  5. Recommendations for Using the Case Study Method in International Business Research

    Science.gov (United States)

    Vissak, Tiia

    2010-01-01

    The case study method has not been as frequently used in international business (IB) research as quantitative methods. Moreover, it has been sometimes misused and quite often criticized. Still, it can be very useful for understanding such complex phenomena as the internationalization process or the management of multinational enterprises. Based on…

  6. High-Speed Measurement of the Internal Diameter of Tubes: A Comparison of Methods

    DEFF Research Database (Denmark)

    Gundtoft, Hans Erik; Agerup, C.C.; Nielsen, N.

    1974-01-01

    The authors have compared various methods of tube measurement and have made the striking conclusion that the continuous measurement of the internal diameter of precision tubes with an air gauge is often useless in practice. The methods selected for experiment were all contactless and so included...

  7. Analysis of forecasting methods of cargo flows in International transportation by land transport

    OpenAIRE

    Ponomareva, N.

    2005-01-01

    Advantages and disadvantages of the existing forecasting methods of cargo flows are presented. The improvement of cargo flows forecasting method in international transportation by land transport is considered on the basis of a interregional balance model to get more correct and fuller forecast.

  8. Comparison of tritiated and iodinated tracers in the radioimmunoassay of progesterone in cow milk

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R M; Redshaw, M R [Hoechst Pharmaceuticals Research Ltd., Milton Keynes (UK); Holdsworth, R [Milk Marketing Board, Worcester (UK). Veterinary Research Unit

    1980-01-01

    Progesterone levels in the milk of cows were determined by two radioimmunoassay methods. Excellent correlation (r = 0.95) was found between the method using an iodinated radioligand and that using a conventional tritiated tracer.

  9. ARN Training Course on Advance Methods for Internal Dose Assessment: Application of Ideas Guidelines

    International Nuclear Information System (INIS)

    Rojo, A.M.; Gomez Parada, I.; Puerta Yepes, N.; Gossio, S.

    2010-01-01

    Dose assessment in case of internal exposure involves the estimation of committed effective dose based on the interpretation of bioassay measurement, and the assumptions of hypotheses on the characteristics of the radioactive material and the time pattern and the pathway of intake. The IDEAS Guidelines provide a method to harmonize dose evaluations using criteria and flow chart procedures to be followed step by step. The EURADOS Working Group 7 'Internal Dosimetry', in collaboration with IAEA and Czech Technical University (CTU) in Prague, promoted the 'EURADOS/IAEA Regional Training Course on Advanced Methods for Internal Dose Assessment: Application of IDEAS Guidelines' to broaden and encourage the use of IDEAS Guidelines, which took place in Prague (Czech Republic) from 2-6 February 2009. The ARN identified the relevance of this training and asked for a place for participating on this activity. After that, the first training course in Argentina took place from 24-28 August for training local internal dosimetry experts. (authors)

  10. Hydroelastic model of PWR reactor internals SAFRAN 1 - Validation of a vibration calculation method

    International Nuclear Information System (INIS)

    Epstein, A.; Gibert, R.J.; Jeanpierre, F.; Livolant, M.

    1978-01-01

    The SAFRAN 1 test loop consists of an hydroelastic similitude of a 1/8 scale model of a 3 loop P.W.R. Vibrations of the main internals (thermal shield and core barrel) and pressure fluctuations in water thin sections between vessel and internals, and in inlet and outlet pipes, have been measured. The calculation method consists of: an evaluation of the main vibration and acoustic sources owing to the flow (unsteady jet impingement on the core barrel, turbulent flow in a water thin section). A calculation of the internal modal parameters taking into account the inertial effects of fluid (the computer codes AQUAMODE and TRISTANA have been used). A calculation of the acoustic response of the circuit (the computer code VIBRAPHONE has been used). The good agreement between the calculation and the experimental results allows using this method with better security for the prediction of the vibration levels of full scale P.W.R. internals

  11. Statistical dynamic imaging of RI-labeled tracer from list-mode PET data

    International Nuclear Information System (INIS)

    Tanimoto, Michiaki; Kuroda, Yoshihiro; Oshiro, Osamu; Watabe, Hiroshi; Kuroda, Tomohiro

    2009-01-01

    Positron emission tomography (PET) can be used in physiological analysis to illustrate physiological states by visualizing the accumulation of radioisotope (RI)-labeled tracer in specific organs or tissues. PET obtains spatio-temporal statistics in the form of list-mode data. However, conventional imaging techniques, which sum up list-mode data over a given time period, cannot depict detailed temporal dynamics of the RI-labeled tracer. In this study, a spatio-temporal analysis approach was employed to visualize the temporal flow dynamics of RI-labeled tracer from the obtained list-mode data. Experiments to assess the visualization of simulated RI-labeled tracer dynamics as well as RI-labeled tracer dynamics in a vascular phantom showed that the proposed method successfully depicted detailed temporal flow dynamics that could not be visualized using conventional methods. (author)

  12. Quantitative amino acid profiling and stable isotopically labeled amino acid tracer enrichment used for in vivo human systemic and tissue kinetics measurements

    DEFF Research Database (Denmark)

    Bornø, Andreas; van Hall, Gerrit

    2014-01-01

    An important area within clinical functional metabolomics is in vivo amino acid metabolism and protein turnover measurements for which accurate amino acid concentrations and stable isotopically labeled amino acid enrichments are mandatory not the least when tissue metabolomics is determined....... The present study describes a new sensitive liquid chromatography tandem mass-spectrometry method quantifying 20 amino acids and their tracer(s) ([ring-(13)C6]/D5Phenylalanine) in human plasma and skeletal muscle specimens. Before analysis amino acids were extracted and purified via deprotonization....../ion exchange, derivatized using a phenylisothiocyanate reagent and each amino acid was quantitated with its own stable isotopically labeled internal standard (uniformly labeled-(13)C/(15)N). The method was validated according to general recommendations for chromatographic analytical methods. The calibration...

  13. Methods for estimation of internal dose of the public from dietary

    International Nuclear Information System (INIS)

    Zhu Hongda

    1987-01-01

    Following the issue of its Publication 26, ICRP has successively published its Publication 30 to meet the great changes and improvements made in the Basic Recommendations since July of 1979. In Part 1 of Publcation 30, ICRP recommended a new method for internal dose estimation and pressented some important data. In this report, comparison is made among methods for estimation of internal dose for the public from dietary. They include: (1) the new method suggested by ICRP; (2) the simple and convenient method using transfer factors under equilibrium conditions; (3) the methods based on the similarities of several radionuclides to their chemical analogs. It is concluded that the first method is better than the others and should be used from now on

  14. How well do different tracers constrain the firn diffusivity profile?

    Directory of Open Access Journals (Sweden)

    C. M. Trudinger

    2013-02-01

    Full Text Available Firn air transport models are used to interpret measurements of the composition of air in firn and bubbles trapped in ice in order to reconstruct past atmospheric composition. The diffusivity profile in the firn is usually calibrated by comparing modelled and measured concentrations for tracers with known atmospheric history. However, in most cases this is an under-determined inverse problem, often with multiple solutions giving an adequate fit to the data (this is known as equifinality. Here we describe a method to estimate the firn diffusivity profile that allows multiple solutions to be identified, in order to quantify the uncertainty in diffusivity due to equifinality. We then look at how well different combinations of tracers constrain the firn diffusivity profile. Tracers with rapid atmospheric variations like CH3CCl3, HFCs and 14CO2 are most useful for constraining molecular diffusivity, while &delta:15N2 is useful for constraining parameters related to convective mixing near the surface. When errors in the observations are small and Gaussian, three carefully selected tracers are able to constrain the molecular diffusivity profile well with minimal equifinality. However, with realistic data errors or additional processes to constrain, there is benefit to including as many tracers as possible to reduce the uncertainties. We calculate CO2 age distributions and their spectral widths with uncertainties for five firn sites (NEEM, DE08-2, DSSW20K, South Pole 1995 and South Pole 2001 with quite different characteristics and tracers available for calibration. We recommend moving away from the use of a firn model with one calibrated parameter set to infer atmospheric histories, and instead suggest using multiple parameter sets, preferably with multiple representations of uncertain processes, to assist in quantification of the uncertainties.

  15. Application of x-ray method for measuring internal stress in the gear teeth surface layer

    International Nuclear Information System (INIS)

    Zaborowski, T.

    1996-01-01

    This paper presents the methodics of the internal stress measurements concerning cylindrical gear teeth of involute profile. There are the method selected, relation between stress and strain presented and conditions of investigation discussed in the study, including preparation of samples for investigation and conditions of the strain measurement. Exemplifying results of stress measurements for teeth of gears made of 4OH steel are shown. Suitability of the developed investigation method is indicated

  16. A Method to Construct Plasma with Nonlinear Density Enhancement Effect in Multiple Internal Inductively Coupled Plasmas

    International Nuclear Information System (INIS)

    Chen Zhipeng; Li Hong; Liu Qiuyan; Luo Chen; Xie Jinlin; Liu Wandong

    2011-01-01

    A method is proposed to built up plasma based on a nonlinear enhancement phenomenon of plasma density with discharge by multiple internal antennas simultaneously. It turns out that the plasma density under multiple sources is higher than the linear summation of the density under each source. This effect is helpful to reduce the fast exponential decay of plasma density in single internal inductively coupled plasma source and generating a larger-area plasma with multiple internal inductively coupled plasma sources. After a careful study on the balance between the enhancement and the decay of plasma density in experiments, a plasma is built up by four sources, which proves the feasibility of this method. According to the method, more sources and more intensive enhancement effect can be employed to further build up a high-density, large-area plasma for different applications. (low temperature plasma)

  17. Doublet Tracer Testing in Klamath Falls, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, J.S.; Johnson, S.E.; Horne, R.N.; Jackson, P. B. [Pet. Eng. Dept., Stanford University; Culver, G.G. [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

    0001-01-01

    A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

  18. Doublet Tracer Testing in Klamath Falls, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Gudmundsson, J S; Johnson, S E; Horne, R N; Jackson, P B [Pet. Eng. Dept., Stanford University; Culver, G G [Geo-Heat Center, Oregon Institute of Technology, Klamath Falls, OR

    0000-12-30

    A tracer test was carried out in a geothermal doublet system to study the injection behavior of a developed reservoir known to be fractured. The doublet produces about 320 gpm of 160 degrees Fahrenheit water that is used for space heating and then injected; the wells are spaced 250 ft apart. Tracer breakthrough was observed in 2 hours and 45 minutes in the production well, indicating fracture flow. However, the tracer concentrations were low and indicated porous media flow; the tracers mixed with a reservoir volume much larger than a fracture.

  19. Principles and techniques of gamma ray tracers

    International Nuclear Information System (INIS)

    Claxton, K.T.

    1978-01-01

    Radioactive tracer techniques provide a very sensitive means of studying physical and chemical processes in a whole variety of different media. Some of the techniques and principles of radioactive tracers and their application to practical engineering systems are discussed. Information which has been found useful in the design of high temperature liquid sodium facilities employing radio-tracers, is presented. The report deals solely with the use of gamma-emitting species as the tracer. These find particular application for in-situ studies on engineering systems where the highly penetrating properties of gamma rays are needed for detection through strongly absorbent media such as stainless steel pepe walls. (author)

  20. Use of artificial tracers in hydrology

    International Nuclear Information System (INIS)

    1991-05-01

    The IAEA has convened an Advisory Group Meeting with the following objectives: To define the role of artificial radioactive tracers for water tracing in comparison with other non-radioactive tracers. To evaluate the real needs of artificial radioactive tracers in hydrology. To identify the fields for which artificial radioactive tracers are useful as well as those in which they can be substituted by other tracers. To discuss the strategy to be adopted to overcome the difficulties derived from the restrictions on the use of radioactive tracers in hydrology. The meeting was held at IAEA Headquarters from 19 to 22 March 1990, and was attended by 30 participants from 15 Member States. The conclusions and recommendations are that the use of artificial radioactive tracers should be restricted to cases where other tracers cannot be used or do not provide the same quality of information. Tritium, iodine-131, bromine-82, chromium-51 in the form of Cr-EDTA, technetium-99m obtained from 99 Mo-generators and gold-198 as an adsorbable tracer are, practically, the only radionuclides used for water tracing. The use of other radionuclides for this purpose does not appear to be necessary, possible and/or convenient. Refs, figs and tabs

  1. GRAPH-BASED POST INCIDENT INTERNAL AUDIT METHOD OF COMPUTER EQUIPMENT

    Directory of Open Access Journals (Sweden)

    I. S. Pantiukhin

    2016-05-01

    Full Text Available Graph-based post incident internal audit method of computer equipment is proposed. The essence of the proposed solution consists in the establishing of relationships among hard disk damps (image, RAM and network. This method is intended for description of information security incident properties during the internal post incident audit of computer equipment. Hard disk damps receiving and formation process takes place at the first step. It is followed by separation of these damps into the set of components. The set of components includes a large set of attributes that forms the basis for the formation of the graph. Separated data is recorded into the non-relational database management system (NoSQL that is adapted for graph storage, fast access and processing. Damps linking application method is applied at the final step. The presented method gives the possibility to human expert in information security or computer forensics for more precise, informative internal audit of computer equipment. The proposed method allows reducing the time spent on internal audit of computer equipment, increasing accuracy and informativeness of such audit. The method has a development potential and can be applied along with the other components in the tasks of users’ identification and computer forensics.

  2. New SPECT and PET dementia tracers

    International Nuclear Information System (INIS)

    Vergote, J.; Chalon, S.; Emond, P.; Vercouillie, J.; Guilloteau, D.; Vergote, J.; Guilloteau, D.; Pappata, J.S.

    2009-01-01

    Single photon emission tomography (SPECT) and positron emission tomography (PET) are techniques to study in vivo neurotransmitter systems, neuro inflammation and amyloid deposits in normal human brain and in dementia. These methods used to explore the integrity of dopaminergic, cholinergic and serotonergic systems in Alzheimer's disease and in other dementias allowed to understand how the neurotransmission was modified in these disorders. Progress in the understanding of pathophysiological and clinical signs of dementia requires an evolution of the radioligands used to carry out an increasingly early and differential diagnosis in addition to monitoring the progression of disease and the effects of therapies. New emerging radiotracers for neuro inflammation or amyloid deposits are essential. In this article, new SPECT and PET tracers are presented. (authors)

  3. Unit vent airflow measurements using a tracer gas technique

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.G. [Union Electric Company, Fulton, MO (United States); Lagus, P.L. [Lagus Applied Technology, Inc., San Diego, CA (United States); Fleming, K.M. [NCS Corp., Columbus, OH (United States)

    1997-08-01

    An alternative method for assessing flowrates that does not depend on point measurements of air flow velocity is the constant tracer injection technique. In this method one injects a tracer gas at a constant rate into a duct and measures the resulting concentration downstream of the injection point. A simple equation derived from the conservation of mass allows calculation of the flowrate at the point of injection. Flowrate data obtained using both a pitot tube and a flow measuring station were compared with tracer gas flowrate measurements in the unit vent duct at the Callaway Nuclear Station during late 1995 and early 1996. These data are presented and discussed with an eye toward obtaining precise flowrate data for release rate calculations. The advantages and disadvantages of the technique are also described. In those test situations for which many flowrate combinations are required, or in large area ducts, a tracer flowrate determination requires fewer man-hours than does a conventional traverse-based technique and does not require knowledge of the duct area. 6 refs., 10 figs., 6 tabs.

  4. Systematization of the Methods for Evaluating the International Competitiveness of Enterprise

    Directory of Open Access Journals (Sweden)

    Shtal Tetyana V.

    2016-01-01

    Full Text Available The article is aimed at studying methods for evaluating competitiveness, identifying their practical relevance to domestic enterprises on example of the ОАО «Zavod «Yuzhkabel». A system of methods for evaluating international competitiveness of enterprises has been analyzed, the most frequently encountered in the economic literature methodologies for estimation have been considered. As a result, weaknesses of the individual elements of the system have been identified. Practical significance of the study has been disclosed, the most effective methods for evaluating the international competitiveness of enterprises have been identified. Using methods such as the method of rating estimation, the «4Р» matrix, the «McKinsey» matrix, the HirfindahlHirschman index and the polygon of competitiveness model, international competitiveness of the ОАО «Zavod «Yuzhkabel» has been evaluated. Conclusion about the extent of enterprise's presence at the international market has been made.

  5. A Local Region of Interest Imaging Method for Electrical Impedance Tomography with Internal Electrodes

    Directory of Open Access Journals (Sweden)

    Hyeuknam Kwon

    2013-01-01

    Full Text Available Electrical Impedance Tomography (EIT is a very attractive functional imaging method despite the low sensitivity and resolution. The use of internal electrodes with the conventional reconstruction algorithms was not enough to enhance image resolution and accuracy in the region of interest (ROI. We propose a local ROI imaging method with internal electrodes developed from careful analysis of the sensitivity matrix that is designed to reduce the sensitivity of the voxels outside the local region and optimize the sensitivity of the voxel inside the local region. We perform numerical simulations and physical measurements to demonstrate the localized EIT imaging method. In preliminary results with multiple objects we show the benefits of using an internal electrode and the improved resolution due to the local ROI image reconstruction method. The sensitivity is further increased by allowing the surface electrodes to be unevenly spaced with a higher density of surface electrodes near the ROI. Also, we analyse how much the image quality is improved using several performance parameters for comparison. While these have not yet been studied in depth, it convincingly shows an improvement in local sensitivity in images obtained with an internal electrode in comparison to a standard reconstruction method.

  6. Relative distance between tracers as a measure of diffusivity within moving aggregates

    Science.gov (United States)

    Pönisch, Wolfram; Zaburdaev, Vasily

    2018-02-01

    Tracking of particles, be it a passive tracer or an actively moving bacterium in the growing bacterial colony, is a powerful technique to probe the physical properties of the environment of the particles. One of the most common measures of particle motion driven by fluctuations and random forces is its diffusivity, which is routinely obtained by measuring the mean squared displacement of the particles. However, often the tracer particles may be moving in a domain or an aggregate which itself experiences some regular or random motion and thus masks the diffusivity of tracers. Here we provide a method for assessing the diffusivity of tracer particles within mobile aggregates by measuring the so-called mean squared relative distance (MSRD) between two tracers. We provide analytical expressions for both the ensemble and time averaged MSRD allowing for direct identification of diffusivities from experimental data.

  7. Improvement of the qualitative and quantitative detection of simultaneously present fluorescent tracers by systematic sample treatment

    International Nuclear Information System (INIS)

    Behrens, H.

    1982-01-01

    The selective instrumental detection of individual fluorescent tracers in mixtures containing further fluorescent dyes is limited by spectral interferences. Therefore additional separations or other suitable procedures have to be included into the analytic technique. With the method described below, the respective tracer to be detected remains with its initial concentration in the sample and is analysed under the appropriate conditions, whereas the interfering tracers are separated or suppressed. The techniques applied for this base on the facts that 1) the fluorescence intensity of the tracers varies differently when the pH-value changes; 2) the tracers show different absorption behaviour and 3) they provide different degrees of light sensitivity. The procedures permit for example to detect uranin when eosin is present in a higher concentration or to detect eosin when amidorhodamin G is present. (orig.) [de

  8. The fluorescent tracer experiment on Holiday Beach near Mugu Canyon, Southern California

    Science.gov (United States)

    Kinsman, Nicole; Xu, J. P.

    2012-01-01

    After revisiting sand tracer techniques originally developed in the 1960s, a range of fluorescent coating formulations were tested in the laboratory. Explicit steps are presented for the preparation of the formulation evaluated to have superior attributes, a thermoplastic pigment/dye in a colloidal mixture with a vinyl chloride/vinyl acetate copolymer. In September 2010, 0.59 cubic meters of fluorescent tracer material was injected into the littoral zone about 4 kilometers upcoast of Mugu submarine canyon in California. The movement of tracer was monitored in three dimensions over the course of 4 days using manual and automated techniques. Detailed observations of the tracer's behavior in the coastal zone indicate that this tracer successfully mimicked the native beach sand and similar methods could be used to validate models of tracer movement in this type of environment. Recommendations including how to time successful tracer studies and how to scale the field of view of automated camera systems are presented along with the advantages and disadvantages of the described tracer methodology.

  9. Temporary metal internal stent dilation for colorectal obstruction and effect on operation methods

    International Nuclear Information System (INIS)

    Chen Niwei; Cheng Yingsheng; Fan Youben; Jin Huimin; Xu Huimin

    2005-01-01

    Objective: To explore the methods and clinical value of temporary internal metal stent through endoscopy under X ray control for treating patients with malignant colorectal obstruction. Methods: 27 patients with malignant colorectal obstruction were treated by temporary metallic internal stent placement via endoscopy under the X ray guidance. Results: 27 patients with colorectal obstruction symptoms were all got rid of the trouble within 48 hours after the stent placement. Selective stage I colorectal cancer resection and anastomosis were performed after bowel preparation. Conclusions: Metallic internal stent placement can loosen the colorectal obstructive symptoms with higher successful rate via endoscopy under X ray control and furthermore for promotion of stage I colorectal cancer resection and anastomosis. (authors)

  10. 14th International Conference on Integral Methods in Science and Engineering

    CERN Document Server

    Riva, Matteo; Lamberti, Pier; Musolino, Paolo

    2017-01-01

    This contributed volume contains a collection of articles on the most recent advances in integral methods.  The first of two volumes, this work focuses on the construction of theoretical integral methods. Written by internationally recognized researchers, the chapters in this book are based on talks given at the Fourteenth International Conference on Integral Methods in Science and Engineering, held July 25-29, 2016, in Padova, Italy. A broad range of topics is addressed, such as: • Integral equations • Homogenization • Duality methods • Optimal design • Conformal techniques This collection will be of interest to researchers in applied mathematics, physics, and mechanical and electrical engineering, as well as graduate students in these disciplines, and to other professionals who use integration as an essential tool in their work.

  11. 8th International Conference on Soft Methods in Probability and Statistics

    CERN Document Server

    Giordani, Paolo; Vantaggi, Barbara; Gagolewski, Marek; Gil, María; Grzegorzewski, Przemysław; Hryniewicz, Olgierd

    2017-01-01

    This proceedings volume is a collection of peer reviewed papers presented at the 8th International Conference on Soft Methods in Probability and Statistics (SMPS 2016) held in Rome (Italy). The book is dedicated to Data science which aims at developing automated methods to analyze massive amounts of data and to extract knowledge from them. It shows how Data science employs various programming techniques and methods of data wrangling, data visualization, machine learning, probability and statistics. The soft methods proposed in this volume represent a collection of tools in these fields that can also be useful for data science.

  12. Rare earths analysis of rock samples by instrumental neutron activation analysis, internal standard method

    International Nuclear Information System (INIS)

    Silachyov, I.

    2016-01-01

    The application of instrumental neutron activation analysis for the determination of long-lived rare earth elements (REE) in rock samples is considered in this work. Two different methods are statistically compared: the well established external standard method carried out using standard reference materials, and the internal standard method (ISM), using Fe, determined through X-ray fluorescence analysis, as an element-comparator. The ISM proved to be the more precise method for a wide range of REE contents and can be recommended for routine practice. (author)

  13. Anthropology and International Business Research Methods in DBA Teaching: Frameworks for Cultural Awareness.

    Science.gov (United States)

    Whiteley, Alma

    2001-01-01

    Discusses the rationale for introducing anthropology into a doctoral-level international business research methods course. Describes three anthropological frameworks designed for the course: a cultural awareness model adapted from G. Morgan's (1980) idea of paradigmatic orthodoxy; key organizing principles; and a mapping model allowing researchers…

  14. 76 FR 50221 - International Workshop on Alternative Methods for Human and Veterinary Rabies Vaccine Testing...

    Science.gov (United States)

    2011-08-12

    ... and Veterinary Rabies Vaccine Testing: State of the Science and Planning the Way Forward AGENCY... (NICEATM) announces an ``International Workshop on Alternative Methods for Human and Veterinary Rabies... rabies vaccine potency testing, and to develop an implementation strategy to achieve global acceptance...

  15. Controlling internal phosphorus loading in lakes by physical methods to reduce cyanobacterial blooms: a review

    Czech Academy of Sciences Publication Activity Database

    Bormans, M.; Maršálek, Blahoslav; Jančula, Daniel

    2016-01-01

    Roč. 50, č. 3 (2016), s. 407-422 ISSN 1386-2588 Institutional support: RVO:67985939 Keywords : internal P loading * cyanobacterial control * physical in-lake restoration methods * adverse impacts on biota Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.500, year: 2016

  16. Researching Civil Remedies for International Corruption: The Choice of the Functional Comparative Method

    NARCIS (Netherlands)

    A.O. Makinwa (Abiola)

    2009-01-01

    textabstractThis paper motivates the choice of the functional comparative method to research the issue of civil remedies for international corruption. It shows how the social, economic and political factors that have shaped the normative context of the research question point to the functional

  17. Nanoparticle tracers in calcium carbonate porous media

    KAUST Repository

    Li, Yan Vivian; Cathles, Lawrence M.; Archer, Lynden A.

    2014-01-01

    the fractures or channels where flow occurs and thus take much less time to travel between two points. In combination with a chemical tracer they can measure the degree of flow concentration. A prerequisite for tracer applications is that the particles

  18. Tracer filamentation at an unstable ocean front

    Science.gov (United States)

    Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

    2017-11-01

    A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

  19. Dynamic dual-tracer PET reconstruction.

    Science.gov (United States)

    Gao, Fei; Liu, Huafeng; Jian, Yiqiang; Shi, Pengcheng

    2009-01-01

    Although of important medical implications, simultaneous dual-tracer positron emission tomography reconstruction remains a challenging problem, primarily because the photon measurements from dual tracers are overlapped. In this paper, we propose a simultaneous dynamic dual-tracer reconstruction of tissue activity maps based on guidance from tracer kinetics. The dual-tracer reconstruction problem is formulated in a state-space representation, where parallel compartment models serve as continuous-time system equation describing the tracer kinetic processes of dual tracers, and the imaging data is expressed as discrete sampling of the system states in measurement equation. The image reconstruction problem has therefore become a state estimation problem in a continuous-discrete hybrid paradigm, and H infinity filtering is adopted as the estimation strategy. As H infinity filtering makes no assumptions on the system and measurement statistics, robust reconstruction results can be obtained for the dual-tracer PET imaging system where the statistical properties of measurement data and system uncertainty are not available a priori, even when there are disturbances in the kinetic parameters. Experimental results on digital phantoms, Monte Carlo simulations and physical phantoms have demonstrated the superior performance.

  20. Deception Detection: Accuracy Levels Among International Military Officers Using Content and Contextual Questioning Methods

    Science.gov (United States)

    2016-12-01

    deception than any one method on its own. This research project focuses on students at the Naval Postgraduate School (NPS) in Monterey, CA, to...international military officers were also limited on the type of contextual questioning methods and scenarios. These scenarios were not a very good ...research received participation from 52 students . Although the sample size was small, proportionally, 24% is a good response rate for lab research

  1. Leak detection and localization in natural and artificial dams using tracer techniques

    International Nuclear Information System (INIS)

    Molinari, J.

    1975-01-01

    Leak detection and localization procedures using often-unknown techniques of identification by natural or artificial tracers are reported. From the analysis of data supplied by natural tracers, or by artificial tracer methods which involve the direct observation of warning phenomena, it is possible to estimate the extent of the infiltrations, define their origin and under certain circumstances determine the main hydrodynamic flow parameters so that their development may be followed. The examples of application and interpretation were taken from the numerous studies carried out in this field by the CEA, where many original investigation methods have been employed [fr

  2. A volatile tracer-assisted headspace analytical technique for determining the swelling capacity of superabsorbent polymers.

    Science.gov (United States)

    Zhang, Shu-Xin; Jiang, Ran; Chai, Xin-Sheng

    2017-09-01

    This paper reports on a new method for the determination of swelling capacity of superabsorbent polymers by a volatile tracer-assisted headspace gas chromatography (HS-GC). Toluene was used as a tracer and added to the solution for polymers swelling test. Based on the differences of the tracer partitioned between the vapor and hydrogel phase before and after the polymer's swelling capacity, a transition point (corresponding to the material swelling capacity) can be observed when plotting the GC signal of toluene vs. the ratio of solution added to polymers. The present method has good precision (RSDpolymers at the elevated temperatures. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Development and validation of I x V curve tracer for photovoltaic modules

    OpenAIRE

    MÃrcio Leal Macedo Luna

    2016-01-01

    The IxV curves tracers for PV modules are used as a method of diagnosis of problems such as shadowing, faulty connections and degradation conditions. There are several types and brands tracers commercially available, but their costs are quite high in the Brazilian market due to the need to import. This thesis describes the development and validation of a IxV curve tracer for PV modules based on the electronic load method using MOSFET as load to the module. By appropriate variation of the MOSF...

  4. Tracer diffusion in ternary alloys

    International Nuclear Information System (INIS)

    Tahir-Kheli, R.A.

    1985-07-01

    An intuitive extension of the theory for diffusion in dynamic binary alloys given in the preceding paper is presented. This theory has also received an independent derivation, based on more formal procedures, by Holdsworth and Elliott. We present Monte Carlo estimates for diffusion correlation factors, fsup(A), fsup(B), and fsup(C) and compare them with the theory. The agreement between the theoretical results and the Monte Carlo estimates for the correlation factors of the slow particles, i.e., fsup(C) and fsup(B), is found to be generally good. In contrast, for the correlation factor, fsup(A), referring to the diffusion coefficient of fast particles in the system, the theoretical results are found to be systematically lower by a small but resolvable margin. It is suggested that this is occasioned by the neglect of spatial constraints on the scattering of coupled tracer-background particle field pairs. (author)

  5. Transuranic and tracer simulant resuspension

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1977-07-01

    Plutonium resuspension results are summarized for experiments conducted at Rocky Flats, onsite on the Hanford reservation, and for winds blowing from offsite onto the Hanford reservation near the Prosser barricade boundary. In each case, plutonium resuspension was shown by increased airborne plutonium concentrations as a function of either wind speed or as compared to fallout levels. All measured airborne concentrations were below maximum permissible concentrations (MPC). Both plutonium and cesium concentrations on airborne soil were normalized by the quantity of airborne soil sampled. Airborne radionuclide concentrations in μCi/g were related to published values for radionuclide concentrations on surface soils. For this ratio of radionuclide concentration per gram on airborne soil divided by that for ground surface soil, there are eight orders of magnitude uncertainty from 10 -4 to 10 4 . Horizontal plutonium fluxes on airborne nonrespirable soils at all three sites were bracketed within the same three to four orders of magnitude from 10 -7 to 10 -3 μCi/(m 2 day) for plutonium-239 and 10 -8 to 10 -5 μCi/(m 2 day) for plutonium-238. These are the entire experimental base for nonrespirable airborne plutonium transport. Airborne respirable plutonium-239 concentrations increased with wind speed for a southeast wind direction coming from offsite near the Hanford reservation Prosser barricade. Airborne plutonium fluxes on nonrespirable particles had isotopic ratios, 240 Pu/ 239+240 Pu, similar to weapons grade plutonium rather than fallout plutonium. Resuspension rates were summarized for controlled inert particle tracer simulant experiments. Wind resuspension rates for tracers increased with wind speed to about the fifth power

  6. Radiation dose estimates for carbon-11-labelled PET tracers

    International Nuclear Information System (INIS)

    Aart, Jasper van der; Hallett, William A.; Rabiner, Eugenii A.; Passchier, Jan; Comley, Robert A.

    2012-01-01

    Introduction: Carbon-11-labelled positron emission tomography (PET) tracers commonly used in biomedical research expose subjects to ionising radiation. Dosimetry is the measurement of radiation dose, but also commonly refers to the estimation of health risk associated with ionising radiation. This review describes radiation dosimetry of carbon-11-labelled molecules in the context of current PET research and the most widely used regulatory guidelines. Methods: A MEDLINE literature search returned 42 articles; 32 of these were based on human PET data dealing with radiation dosimetry of carbon-11 molecules. Radiation burden expressed as effective dose and maximum absorbed organ dose was compared between tracers. Results: All but one of the carbon-11-labelled PET tracers have an effective dose under 9 μSv/MBq, with a mean of 5.9 μSv/MBq. Data show that serial PET scans in a single subject are feasible for the majority of radiotracers. Conclusion: Although differing in approach, the two most widely used regulatory frameworks (those in the USA and the EU) do not differ substantially with regard to the maximum allowable injected activity per PET study. The predictive validity of animal dosimetry models is critically discussed in relation to human dosimetry. Finally, empirical PET data are related to human dose estimates based on homogenous distribution, generic models and maximum cumulated activities. Despite the contribution of these models to general risk estimation, human dosimetry studies are recommended where continued use of a new PET tracer is foreseen.

  7. Off-gassing induced tracer release from molten basalt pools

    International Nuclear Information System (INIS)

    Cronenberg, A.W.; Callow, R.A.

    1994-01-01

    Two in situ vitrification (ISV) field tests were conducted at the Idaho National Engineering Laboratory (INEL) during the summer of 1990 to assess ISV suitability for long-term stabilization of buried waste that contains transuranic and other radionuclide contaminants. The ISV process uses electrical resistance heating to melt buried waste and soil in place, which upon cooldown and resolidification fixes the waste into a vitrified (glass-like) form. In these two ISV field tests, small quantities of rare-earth oxides (tracers DY 2 O 3 , Yb 2 O 3 , and Tb 4 O 7 ) were placed in the test pits to simulate the presence of plutonium oxides and assess plutonium retention/release behavior. The analysis presented in this report indicates that dissolution of tracer oxides into basaltic melts can be expected with subsequent tracer molecular or microparticle carry-off by escaping gas bubbles, which is similar to adsorptive bubble separation and ion flotation processes employed in the chemical industry to separate dilute heavy species from liquids under gas sparging conditions. Gaseous bubble escape from the melt surface and associated aerosolization is believed to be responsible for small quantities of tracer ejection from the melt surface to the cover hood and off-gas collection system. Methods of controlling off-gassing during ISV would be expected to improve the overall retention of such heavy oxide contaminants during melting/vitrification of buried waste

  8. General circulation and tracers: studies in the Western Indian Ocean

    International Nuclear Information System (INIS)

    Jamous, Daniel

    1991-01-01

    The main question addressed in this thesis is how to best use the information obtained from hydro-biogeochemical tracer data, to study the oceanic general circulation in the Western Indian Ocean. First, a principal component analysis is performed on a historical data set. The tracers considered are temperature, salinity, density, oxygen, phosphate and silica. The method reduces the amount of data to be considered by a factor of 5. It reproduces correctly and efficiently the large-scale distributions of these oceanic properties. The analysed data are then used in a finite-difference nonlinear inverse model. The grid has a resolution of 4 deg. by 4 deg.. Dynamical as well as tracer conservation constraints are used. These constraints are well satisfied by the obtained solutions but the associated errors remain large. Additional constraints would be required in order to discuss the different solutions in more detail. Finally, a qualitative study is done on the deep distribution of helium-3. The data show several important features linked to hydrothermal input in the Gulf of Aden and on the Central Indian Ridge, and to the origin of water masses and deep circulation characteristics. However additional data are required in order to clarify the distribution of this tracer in other key areas. (author) [fr

  9. Characterization and modeling of natural tracers' transfers through the argillites of Tournemire (France)

    International Nuclear Information System (INIS)

    Patriarche, D.

    2001-01-01

    The French Institute for Protection and Nuclear Safety (IPSN) is investigating the argillaceous formation of Tournemire (France) as a methodological underground laboratory for conducting research on the feasibility of deep geological repositories for radioactive waste in argilites. Because of the very low water content and hydraulic conductivity of the argilites, the migration through this media should be very low. The fluid flow regime and transport have been studied using natural tracers from the interstitial water. The deuterium and chloride of interstitial water have been chosen for their conservative behavior. After the development of a protocol for the chloride extraction from the water, and tests on the vacuum distillation method for the water extraction from the rock, systematic data acquisition has been performed on the argillaceous sequence of the massif and near the fracture areas. Both chloride and deuterium profiles suggest that transfers are mainly diffusive at the massif scale. But the profiles show an enrichment in delta D and delta 18 O of the interstitial solution in the area of one meter adjacent to a fracture compared to pore water of samples located at further distance. Therefore, these observations are suggesting that a second process could generate specific transfers, at the vicinity of faults. The hypothesis of the molecular diffusion as a dominant process for transport was successfully tested using a transport model, over periods of several tenth of millions years, taking into account geodynamical features of the region (such as tectonic and induced faults), and assuming that some variations of the tracer concentrations at the system boundaries occurred during the major climate-change periods. Even if tracers' transfers are mainly diffusive at the massif scale, they are or should have been affected by a second process causing heterogeneity of concentrations at the vicinity of faults. This process involves either, intrusion of salted

  10. A novel method for improving chest tube insertion skills among medical interns

    Science.gov (United States)

    Tatli, Ozgur; Turkmen, Suha; Imamoglu, Melih; Karaca, Yunus; Cicek, Mustafa; Yadigaroglu, Metin; Bayrak, Selen T.; Asik, Olgun; Topbas, Murat; Turedi, Suleyman

    2017-01-01

    Objectives: To develop a low-cost biomaterial-covered chest tube simulation model and assess its possible usefulness for developing the chest tube insertion skills among medical interns. Methods: This mannequin-based interventional study was performed in a University hospital setting. We included 63 physicians performing emergency medicine internship at the Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, between January 2015 and March 2015. A dummy was prepared for training simulation using a display mannequin. Medical interns received instruction concerning pneumothorax and the chest tube procedure. A total of 63 medical interns participating in this interventional study were asked to insert a chest tube in a biomaterial-covered mannequin. A senior trainee scored their performance using a check list and the mean of the total scores was calculated (21 items; total score, 42). Results: The mean procedural score was 40.9 ± 1.3 of a possible 42. The maximum score of 42 was achieved by 39.7% of the medical interns, while another 33.3% achieved a score of 41. Of the participants, 85% succeeded in inserting the tube via an appropriate technique, achieving a score of 40 or more. Conclusion: Our results indicated that this model could be useful for effective training of medical interns for chest tube insertion, which is an important skill in emergency medicine. This biomaterial-covered model is inexpensive and its use can potentially be widened to improve training methods without significant financial demand. PMID:28917064

  11. Method validation to measure Strontium-90 in urine sample for internal dosimetry assessment

    International Nuclear Information System (INIS)

    Bitar, A.; Maghrabi, M.; Alhamwi, A.

    2010-12-01

    Occupational individuals exposed at some scientific centers in Syrian Arab Republic to potentially significant intake by ingestion or inhalation during process of producing radiopharmaceutical compounds. The received radioactive intake differs in relation to the amount of radionuclides released during the preparation processes, to the work conditions and to the applying ways of the radiation protection procedures. TLD (Thermoluminescence Dosimeter) is usually used for external radiation monitoring for workers in radioisotope centers. During the external monitoring programme, it was noticed that some workers were exposed to high external dose resultant from radiation accident in their laboratory when preparing Y-90 from Sr-90. For internal dose assessment, chemical method to measure the amount of Sr-90 in urine samples was validated and explained in details in this study. Urine bioassays were carried out and the activities of 90 Sr were determined using liquid scintillation counter. Then, the validated method was used for internal occupational monitoring purposes through the design of internal monitoring programme. The programme was established for four workers who are dealing, twice per month, with an amount of about 20 mCi in each time. At the beginning, theoretical study was done to assess maximum risks for workers. Calculated internal doses showed that it is necessary to apply internal routine monitoring programme for those workers. (author)

  12. The Organizational-Methodical Mechanism for Influencing the Status of Internal Communications of Enterprise

    Directory of Open Access Journals (Sweden)

    Saher Liudmyla Yu.

    2017-10-01

    Full Text Available The article explores the essence of the organizational-economic mechanism, defines the main constituent elements and proposes a structural-logical relations diagram of the mechanism for management of the internal communication processes of enterprises. The basic principles of management are allocated, their hierarchy is provided from a position of grade of influence on the process of internal communications management. A list of management methods within the proposed management mechanism (economic, social-psychological, organizational is described. It has been determined that the application of one group of methods in the process of managing the internal communications of enterprise without the use of others cannot have a lasting positive effect, because the management process requires an integrated and systemic approach. The author provides a sequence of phases of the internal communications management based on the process of diagnosing the status of the internal communication processes of enterprise and the formation of strategic directions of activity along with the managerial decision-making on its basis.

  13. Suitable activated carbon-13 tracer techniques

    International Nuclear Information System (INIS)

    Zhang Weicheng; Peng Xiuru; Wang Yuhua

    1995-12-01

    Feasibility and applicability studies of the proton induced gamma ray emission (PIGE) have been performed. The graphite was firstly bombarded at various proton energies to determine gamma ray yield (and, thus, sensitivities) for the reaction of interest. The accuracy for the determination of 13 C abundance was checked, and the precision with which this value and ratios 13 C/ 12 C may be obtained was established by repetitive analysis samples. The performance of different standards in this determination was assessed. The mathematical treatment was developed for the determination of 13 C abundance in tracer studies, and to derive the equations that govern this method of analysis from first principles, to arrive finally at a simple expression by virtue of the observed regularities. The system was calibrated by measuring the gamma ray yield form the 12 C (p, γ) 13 N and 13 C(p,γ) 14 N reaction as a function of known 13 C enrichment. Using this experimentally determined calibration curve, unknown materials can be assayed. This technique is applicable to the analysis of samples with 13 C enrichments between 0.1% and 90%. The samples of human breath natural samples were analyzed against graphite and Cylinder CO 2 standards. Relative standard deviations were 13 C abundance, an increase in 13 C per cent isotopic abundance from the natural 1.11% (average) to only 1.39% may be ascertained. Finally, PIGE is compared with more classical techniques for analysis of 13 C tracer experiments. Ease and speed are important advantages of this technique over mass spectrometry, and its error is compatible with the natural variation of biological results. (9 refs., 11 figs., 9 tabs.)

  14. Use of tracer technique in estimation of methane (green house gas) from ruminant

    International Nuclear Information System (INIS)

    Singh, G.P.

    1996-01-01

    Several methods developed to estimate the methane emission by ruminant livestock like feed fermentation based technique, using radioisotope as tracer, respiration chamber, etc. have been discussed. 6 refs., 3 figs

  15. Abstracts from the international conference on nuclear analytical methods in the life sciences

    International Nuclear Information System (INIS)

    1994-01-01

    The proceedings contain short communications of 133 papers presented at the conference. All these contributions have been inputted to INIS. The majority of papers deal with the determination of trace elements in biological and environmental samples using neutron activation analysis, X-ray fluorescence analysis, PIXE analysis and tracer techniques. (Z.S.)

  16. Method of using sacrificial materials for fabricating internal cavities in laminated dielectric structures

    Science.gov (United States)

    Peterson, Kenneth A [Albuquerque, NM

    2009-02-24

    A method of using sacrificial materials for fabricating internal cavities and channels in laminated dielectric structures, which can be used as dielectric substrates and package mounts for microelectronic and microfluidic devices. A sacrificial mandrel is placed in-between two or more sheets of a deformable dielectric material (e.g., unfired LTCC glass/ceramic dielectric), wherein the sacrificial mandrel is not inserted into a cutout made in any of the sheets. The stack of sheets is laminated together, which deforms the sheet or sheets around the sacrificial mandrel. After lamination, the mandrel is removed, (e.g., during LTCC burnout), thereby creating a hollow internal cavity in the monolithic ceramic structure.

  17. An Overview of Internal and External Fixation Methods for the Diabetic Charcot Foot and Ankle.

    Science.gov (United States)

    Ramanujam, Crystal L; Zgonis, Thomas

    2017-01-01

    Diabetic Charcot neuroarthropathy (DCN) of the foot and ankle is a challenging disease with regard to clinical presentation, pathogenesis, and prognosis. Its surgical management is equally difficult to interpret based on the wide array of options available. In the presence of an ulceration or concomitant osteomyelitis, internal fixation by means of screws, plates, or intramedullary nailing needs to be avoided when feasible. External fixation becomes a great surgical tool when managing DCN with concomitant osteomyelitis. This article describes internal and external fixation methods along with available literature to enlighten surgeons faced with treating this complex condition. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A thermal extrapolation method for the effective temperatures and internal energies of activated ions

    Science.gov (United States)

    Meot-Ner (Mautner), Michael; Somogyi, Árpád

    2007-11-01

    The internal energies of dissociating ions, activated chemically or collisionally, can be estimated using the kinetics of thermal dissociation. The thermal Arrhenius parameters can be combined with the observed dissociation rate of the activated ions using kdiss = Athermalexp(-Ea,thermal/RTeff). This Arrhenius-type relation yields the effective temperature, Teff, at which the ions would dissociate thermally at the same rate, or yield the same product distributions, as the activated ions. In turn, Teff is used to calculate the internal energy of the ions and the energy deposited by the activation process. The method yields an energy deposition efficiency of 10% for a chemical ionization proton transfer reaction and 8-26% for the surface collisions of various peptide ions. Internal energies of ions activated by chemical ionization or by gas phase collisions, and of ions produced by desorption methods such as fast atom bombardment, can be also evaluated. Thermal extrapolation is especially useful for ion-molecule reaction products and for biological ions, where other methods to evaluate internal energies are laborious or unavailable.

  19. Experimental plan for tracer testing in the Culebra Dolomite at the WIPP site

    International Nuclear Information System (INIS)

    Beauheim, R.L.; Davies, P.B.

    1992-01-01

    This Experimental Plan provides a conceptual description of a proposed series of tracer tests to be conducted in the Culebra Dolomite Member of the Rustler Formation at the WIPP site. The new tracer tests are intended to address deficiencies that have been identified both in the performance and interpretation of previously conducted tracer tests' Tracer tests were conducted at the H-2 hydropad in 1980, at the H-6 hydropad in 1981, 1982, and 1983, at the H-4 hydropad from 1982 to 1984, at the H-3 hydropad in 1984, and at the H-11 hydropad in 1988. These tests were all performed over the entire 7-m thickness of the Culebra and, therefore, provided no information on the effects of vertical heterogeneity within the Culebra on transport. In addition, each of the previous tracer tests provided data only from 1 to 3 flow paths, allowing calibration of interpretive models but not validation of those models. The tracer tests at the H-3, H-6, and H-11 hydropads have been interpreted using a double-porosity continuum model (SWIFT 11) in which advective transport occurs through a uniform network of fractures while diffusion of tracer from the fractures to the porosity in the rock matrix causes a physical retardation of the transport. External reviewers, particularly participants in the international INTRAVAL program, have suggested that alternative mechanisms, such as fracture channeling, could explain the observed physical retardation and have recommended that additional tracer tests be designed and performed to distinguish among these mechanisms. The previous tracer tests also provided no information on chemical-retardation processes within the Culebra, which have been shown through performance-assessment calculations to have a large impact on cumulative releases of radionuclides from the WIPP to the accessible environment

  20. Influence of different methods of internal bone fixation on characteristics of bone callus in experimental animals

    Directory of Open Access Journals (Sweden)

    Gajdobranski Đorđe

    2014-01-01

    Full Text Available Introduction. Correct choice of osteosynthesis method is a very important factor in providing the optimal conditions for appropriate healing of the fracture. There are still disagreements about the method of stabilization of some long bone fractures. Critically observed, no method of fracture fixation is ideal. Each osteosynthesis method has both advantages and weaknesses. Objective. The objective of this study was to compare the results of the experimental application of three different internal fixation methods: plate fixation, intramedullary nail fixation and self-dynamisable internal fixator (SIF. Methods. A series of 30 animals were used (Lepus cuniculus as experimental animals, divided into three groups of ten animals each. Femoral diaphysis of each animal was osteotomized and fixed with one of three implants. Ten weeks later all animals were sacrificed and each specimen underwent histological and biomechanical testing. Results. Histology showed that the healing process with SIF was more complete and bone callus was more mature in comparison to other two methods. During biomechanical investigation (computerized bending stress test, it was documented with high statistical significance that using SIF led to stronger healing ten weeks after the operation. Conclusion. According to the results obtained in this study, it can be concluded that SIF is a suitable method for fracture treatment.

  1. Method for remote diagnostics of the internal structure of layered media

    International Nuclear Information System (INIS)

    Lychagov, V V; Kal'yanov, A L; Ryabukho, V P; Lyakin, D V

    2008-01-01

    The method of autocorrelation low coherence interferometry is proposed for diagnostics of inhomogeneities and the internal structure of layered technical and biological samples. In this method the low coherence optical field reflected from the layered sample is analysed by using a Michelson interferometer. Because the object is outside the interferometer, the distance between the interferometer and the object under study is not limited and thus the object can move during the measurements. Theoretical substantiation of the autocorrelation method for media with discrete and continuous optical structure modifications is presented. (special issue devoted to application of laser technologies in biophotonics and biomedical studies)

  2. Application of case analysis teaching method in nursing teaching in Department of Internal Medicine

    Directory of Open Access Journals (Sweden)

    Zhang-xiu SHENG

    2014-04-01

    Full Text Available Objective:In order to adapt to the modern occupation education teaching idea, to stimulate students’ interest in learning, training students' comprehensive quality, improve the students' active participation, understanding, analysis and problem solving skills. Methods: I In the course of different stages using teaching methods of case analysis: case introduction before class teaching method, case analysis during and after class teaching method, and case analysis of the whole chapter after class teaching method.  Results and Conclusion: Through the course of different stages of using case analysis teaching method, we can launch the students’ active learning, stimulate the students' interest in learning, activate classroom atmosphere, train students' independent thinking, strengthen the problems solving ability, improve the self-learning ability of students, activate their participation and awareness, analysis, judgment, introduction, and strengthen students' exam ability, improve the test scores of students and the teaching effect of nursing in Department of internal medicine.

  3. A measurement method for determination of dc internal resistance of batteries and supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shuhong; Wu, Feng [Department of Materials Science, Beijing Science and Technology University, Beijing 100081 (China); Yang, Liuxiang; Gao, Lijun [Department of Chemistry, NanChang University, JiangXi 330031 (China); Burke, Andrew F. [Institute of Transportation, University of California, Davis, CA 95616 (United States)

    2010-02-15

    Internal resistance is an importance parameter determining the power performance of a battery or supercapacitor. An 8.5 Ah Li-ion battery and a 350 F supercapacitor were tested as examples to validate the measurement method of dc internal resistance. Voltage data were taken at 10 ms, 2 s and 30 s after the current interruption or pulse. The ac resistances at 1 kHz of the battery and supercapacitor were also measured for comparison with the dc values. Based on these tests, it is proposed that the dc internal resistance of the battery and supercapacitor be obtained from {delta}V/{delta}I where the {delta}V is the voltage change after the current interruption, and {delta}I means current change from I to 0. When the voltage change at 10 ms or less is selected, the resistance corresponds to the Ohmic resistance of the device. (author)

  4. Use of natural geochemical tracers to improve reservoir simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Huseby, O.; Chatzichristos, C.; Sagen, J.; Muller, J.; Kleven, R.; Bennett, B.; Larter, S.; Stubos, A.K.; Adler, P.M.

    2005-01-01

    This article introduces a methodology for integrating geochemical data in reservoir simulations to improve hydrocarbon reservoir models. The method exploits routine measurements of naturally existing inorganic ion concentration in hydrocarbon reservoir production wells, and uses the ions as non-partitioning water tracers. The methodology is demonstrated on a North Sea field case, using the field's reservoir model, together with geochemical information (SO{sub 4}{sup 2}, Mg{sup 2+} K{sup +}, Ba{sup 2+}, Sr{sup 2+}, Ca{sup 2+}, Cl{sup -} concentrations) from the field's producers. From the data-set we show that some of the ions behave almost as ideal sea-water tracers, i.e. without sorption to the matrix, ion-exchange with the matrix or scale-formation with other ions in the formation water. Moreover, the dataset shows that ion concentrations in pure formation-water vary according to formation. This information can be used to allocate produced water to specific water-producing zones in commingled production. Based on an evaluation of the applicability of the available data, one inorganic component, SO{sub 4}{sup 2}, is used as a natural seawater tracer. Introducing SO{sub 4}{sup 2} as a natural tracer in a tracer simulation has revealed a potential for improvements of the reservoir model. By tracking the injected seawater it was possible to identify underestimated fault lengths in the reservoir model. The demonstration confirms that geochemical data are valuable additional information for reservoir characterization, and shows that integration of geochemical data into reservoir simulation procedures can improve reservoir simulation models. (author)

  5. Predictive value of tracer studies for 131I treatment in hyperthyroid cats

    International Nuclear Information System (INIS)

    Broome, M.R.; Turrel, J.M.; Hays, M.T.

    1988-01-01

    In 76 cats with hyperthyroidism, peak thyroidal radioiodine ( 131 I) uptakes and effective half-lives were determined after administration of tracer and therapeutic activities of 131 I. In 6 additional hyperthyroid cats, only peak thyroidal uptakes after administration of tracer and therapeutic activities of 131 I were determined. Good correlation was found between peak thyroidal uptakes of tracer and therapeutic 131 I; however, only fair correlation was observed between effective half-lives. In 79% of the cats, the effective half-life for therapeutic 131 I was longer than that for tracer 131 I. After administration of therapeutic activity of 131 I, monoexponential and biphasic decay curves were observed in 51 and 16 cats, respectively. Using therapeutic kinetic data, radiation doses to the thyroid gland were calculated retrospectively on the basis of 2 methods for determining the activity of 131 I administered: (1) actual administration of tracer-compensated activity and (2) hypothetic administration of uniform activity (3 mCi). Because of the good predictive ability of tracer kinetic data for the therapeutic kinetic data, the tracer-compensated radiation doses came significantly (P = 0.008) closer to the therapeutic goal than did the uniform-activity doses. In addition, the use of tracer kinetic information reduced the extent of the tendency for consistently high uniform-activity doses. A manual method for acquiring tracer kinetic data was developed and was an acceptable alternative to computerized techniques. Adoption of this method gives individuals and institutions with limited finances the opportunity to characterize the iodine kinetics in cats before proceeding with administration of therapeutic activities of 131 I

  6. Internal Stress Monitoring of In-Service Structural Steel Members with Ultrasonic Method

    Science.gov (United States)

    Li, Zuohua; He, Jingbo; Teng, Jun; Wang, Ying

    2016-01-01

    Internal stress in structural steel members is an important parameter for steel structures in their design, construction, and service stages. However, it is hard to measure via traditional approaches. Among the existing non-destructive testing (NDT) methods, the ultrasonic method has received the most research attention. Longitudinal critically refracted (Lcr) waves, which propagate parallel to the surface of the material within an effective depth, have shown great potential as an effective stress measurement approach. This paper presents a systematic non-destructive evaluation method to determine the internal stress in in-service structural steel members using Lcr waves. Based on theory of acoustoelasticity, a stress evaluation formula is derived. Factor of stress to acoustic time difference is used to describe the relationship between stress and measurable acoustic results. A testing facility is developed and used to demonstrate the performance of the proposed method. Two steel members are measured by using the proposed method and the traditional strain gauge method for verification. Parametric studies are performed on three steel members and the aluminum plate to investigate the factors that influence the testing results. The results show that the proposed method is effective and accurate for determining stress in in-service structural steel members. PMID:28773347

  7. Internal Stress Monitoring of In-Service Structural Steel Members with Ultrasonic Method.

    Science.gov (United States)

    Li, Zuohua; He, Jingbo; Teng, Jun; Wang, Ying

    2016-03-23

    Internal stress in structural steel members is an important parameter for steel structures in their design, construction, and service stages. However, it is hard to measure via traditional approaches. Among the existing non-destructive testing (NDT) methods, the ultrasonic method has received the most research attention. Longitudinal critically refracted (Lcr) waves, which propagate parallel to the surface of the material within an effective depth, have shown great potential as an effective stress measurement approach. This paper presents a systematic non-destructive evaluation method to determine the internal stress in in-service structural steel members using Lcr waves. Based on theory of acoustoelasticity, a stress evaluation formula is derived. Factor of stress to acoustic time difference is used to describe the relationship between stress and measurable acoustic results. A testing facility is developed and used to demonstrate the performance of the proposed method. Two steel members are measured by using the proposed method and the traditional strain gauge method for verification. Parametric studies are performed on three steel members and the aluminum plate to investigate the factors that influence the testing results. The results show that the proposed method is effective and accurate for determining stress in in-service structural steel members.

  8. A method for gear fatigue life prediction considering the internal flow field of the gear pump

    Science.gov (United States)

    Shen, Haidong; Li, Zhiqiang; Qi, Lele; Qiao, Liang

    2018-01-01

    Gear pump is the most widely used volume type hydraulic pump, and it is the main power source of the hydraulic system. Its performance is influenced by many factors, such as working environment, maintenance, fluid pressure and so on. It is different from the gear transmission system, the internal flow field of gear pump has a greater impact on the gear life, therefore it needs to consider the internal hydraulic system when predicting the gear fatigue life. In this paper, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposing the prediction method based on the virtual simulation. The method use CFD (Computational fluid dynamics) software to analyze pressure distribution of internal flow field of the gear pump, and constructed the unidirectional flow-solid coupling model of gear to acquire the contact stress of tooth surface on Ansys workbench software. Finally, employing nominal stress method and Miner cumulative damage theory to calculated the gear contact fatigue life based on modified material P-S-N curve. Engineering practice show that the method is feasible and efficient.

  9. Internal stress distribution of X-ring using photoelastic experimental hybrid method

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Lim, Hyun Seok [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

    2014-05-15

    Sealing elements are essential parts of many machines, and are used to prevent the loss of a fluid or gas. When such fluids are not properly sealed, catastrophic failures may result. Many different types of rings have been developed to suit various industrial needs. Considerable research has been done on the O-ring. We analyze the internal stresses developed in an X-ring under a uniform squeeze rate of 20%, which is suitable for static applications, using a photoelastic experimental hybrid method. The internal pressures applied were 0.98, 1.96, 2.94, 3.92, 4.90, and 5.88 MPa. We show that sealing rings with X geometry have considerably higher internal stresses than O-ring seals. In addition, we demonstrate that after extrusion, for an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merge, thereby increasing the contact length of the upper side significantly. Extrusion in the X-ring occurred when the internal pressure was 4.90 MPa.

  10. A tracer diffusion model derived from microstructure

    International Nuclear Information System (INIS)

    Lehikoinen, Jarmo; Muurinen, Arto; Olin, Markus

    2012-01-01

    Document available in extended abstract form only. Full text of publication follows: Numerous attempts have been made to explain the tracer diffusion of various solutes in compacted clays. These attempts have commonly suffered from an inability to describe the diffusion of uncharged and charged solutes with a single unified model. Here, an internally consistent approach to describing the diffusion of solutes in a heterogeneous porous medium, such as compacted bentonite, in terms of its microstructure is presented. The microstructure is taken to be represented by a succession of unit cells, which consist of two consecutive regions (Do, 1996). In the first region, the diffusion is viewed to occur in two parallel paths: one through microcrystalline units (micropores) and the other through meso-pores between the microcrystalline units. Solutes exiting these two paths are then joined together to continue diffusing through the second, disordered, region, connecting the two adjacent microcrystalline units. Adsorption (incl. co-ion exclusion) is thought to occur in the micropores, whereas meso-pores and the disordered region accommodate free species alone. Co-ions are also assumed to experience transfer resistance into and out of the micropores, which is characterized in the model by a transmission coefficient. Although the model is not new per se, its application to compacted clays has never been attempted before. It is shown that in the limit of strong adsorption, the effective diffusivity is limited from above only by the microstructural parameters of the model porous medium. As intuitive and logical as this result may appear, it has not been proven before. In the limit of vanishing disordered region, the effective diffusivity is no longer explicitly constrained by any of the model parameters. The tortuosity of the diffusion path, i.e. the quotient of the actual diffusion path length in the porous-medium coordinates and the characteristic length of the laboratory frame

  11. Elevated source SF6-tracer dispersion experiments in the Copenhagen area. Preliminary results II

    International Nuclear Information System (INIS)

    Gryning, S.E.; Lyck, E.

    1980-01-01

    The results from 10 experiments, performed in neutral to unstable meteorological conditions, are reported from an ongoing series of elevated-source, urban-scale tracer dispersion experiments in the Copenhagen area. The tracer is released at a height of 115 m from the TV-tower in GLADSAXE, a suburb of Copenhagen, with tracer sampling units positioned at ground-level in 1 to 3 crosswind series, 2 to 6 km downwind of the tower. The lateral dispersion parameter, sigma(y), was estimated from the measured tracer concentration distribution and compared with values of sigma(y), computed by 1) methods based on wind variance measured during the experiments and 2) methods based on a stability classification of the atmospheric conditions. The wind-variance based methods proved superior in predicting the variation of sigma(y) compared with the stability based methods. Moreover, some of the former methods produced significantly biased estimates of sigma(y). The measured tracer concentration distributions were also crosswind integrated, chi(CWI). Estimates of chi(CWI) were computed using sigma (z) -values derived from the aforementioned computations assuming a Gaussian-type vertical tracer concentration distribution. A comparison is measured and calculated values of chi(CWI) showed no significant differences in the ability of the methods to predict the variation of chi(CWI). Only one method, the EPA, came out with a mean fractional error outside the range +-20% which constitutes the uncertainty in the absolute tracer concentration associated with the calibration of the gas chromatograph for tracer analysis

  12. ARN Training on Advance Methods for Internal Dose Assessment: Application of Ideas Guidelines

    International Nuclear Information System (INIS)

    Rojo, A.M.; Gomez Parada, I.; Puerta Yepes, N.; Gossio, S.

    2010-01-01

    Dose assessment in case of internal exposure involves the estimation of committed effective dose based on the interpretation of bioassay measurement, and the assumptions of hypotheses on the characteristics of the radioactive material and the time pattern and the pathway of intake. The IDEAS Guidelines provide a method to harmonize dose evaluations using criteria and flow chart procedures to be followed step by step. The EURADOS Working Group 7 'Internal Dosimetry', in collaboration with IAEA and Czech Technical University (CTU) in Prague, promoted the 'EURADOS/IAEA Regional Training Course on Advanced Methods for Internal Dose Assessment: Application of IDEAS Guidelines' to broaden and encourage the use of IDEAS Guidelines, which took place in Prague (Czech Republic) from 2-6 February 2009. The ARN identified the relevance of this training and asked for a place for participating on this activity. After that, the first training course in Argentina took place from 24-28 August for training local internal dosimetry experts. This paper resumes the main characteristics of this activity. (authors) [es

  13. Statistically Based Morphodynamic Modeling of Tracer Slowdown

    Science.gov (United States)

    Borhani, S.; Ghasemi, A.; Hill, K. M.; Viparelli, E.

    2017-12-01

    Tracer particles are used to study bedload transport in gravel-bed rivers. One of the advantages associated with using of tracer particles is that they allow for direct measures of the entrainment rates and their size distributions. The main issue in large scale studies with tracer particles is the difference between tracer stone short term and long term behavior. This difference is due to the fact that particles undergo vertical mixing or move to less active locations such as bars or even floodplains. For these reasons the average virtual velocity of tracer particle decreases in time, i.e. the tracer slowdown. In summary, tracer slowdown can have a significant impact on the estimation of bedload transport rate or long term dispersal of contaminated sediment. The vast majority of the morphodynamic models that account for the non-uniformity of the bed material (tracer and not tracer, in this case) are based on a discrete description of the alluvial deposit. The deposit is divided in two different regions; the active layer and the substrate. The active layer is a thin layer in the topmost part of the deposit whose particles can interact with the bed material transport. The substrate is the part of the deposit below the active layer. Due to the discrete representation of the alluvial deposit, active layer models are not able to reproduce tracer slowdown. In this study we try to model the slowdown of tracer particles with the continuous Parker-Paola-Leclair morphodynamic framework. This continuous, i.e. not layer-based, framework is based on a stochastic description of the temporal variation of bed surface elevation, and of the elevation specific particle entrainment and deposition. Particle entrainment rates are computed as a function of the flow and sediment characteristics, while particle deposition is estimated with a step length formulation. Here we present one of the first implementation of the continuum framework at laboratory scale, its validation against

  14. Estimation of Recharge from Long-Term Monitoring of Saline Tracer Transport Using Electrical Resistivity Tomography

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Jensen, Karsten Høgh; Binley, Andrew

    2015-01-01

    The movement of a saline tracer added to the soil surface was monitored in the unsaturated zone using cross-borehole electrical resistivity tomography (ERT) and subjected to natural rainfall conditions. The ERT data were inverted and corrected for subsurface temperature changes, and spatial moment...... methods. In September 2011, a saline tracer was added across a 142-m2 area at the surface at an application rate mimicking natural infiltration. The movement of the saline tracer front was monitored using cross-borehole electrical resistivity tomography (ERT); data were collected on a daily to weekly...

  15. Influence of nutrition on protein synthesis and 15N tracer data in man

    International Nuclear Information System (INIS)

    Faust, H.

    1984-01-01

    Quantitative studies and measurements of parameters of the protein metabolism in vivo require the isotope methodology. Different 15 N tracer methods with special modifications are available which can be used depending on clinical problems. The oral single pulse application of [ 15 N]glycine is equal to other isotope tracer techniques provided that the basic assumptions of the application are fullfilled. The protein metabolism is clearly influenced by the nutritional status whereby the protein synthesis is more sensitive than the breakdown to altered dietary intakes of protein and energy. The importance of standardized experimental conditions is emphasized for studies with 15 N and the interpretation of tracer data. (author)

  16. Tracer tests and image analysis of biological clogging in a two-dimentsional sandbox experiment

    DEFF Research Database (Denmark)

    Kildsgaard, J.; Engesgaard, Peter Knudegaard

    2002-01-01

    A two-dimensional flow experiment on biological clogging was carried out by biostimulating a sandbox packed with sand inoculated with bacteria. Biostimulation. consisted of continuously injecting nutrients (acetate and nitrate). Clogging was visualized by frequently carrying out colored tracer...... experiments using Brilliant Blue. The tracer experiments were recorded with a digital camera and converted to concentration maps using an image-analysis method that revealed in detail the complex spreading pattern surrounding clogged areas. Clogging resulted in a finger-like spreading of the tracer around...

  17. Studies on groundwater transport in fractured crystalline rock under controlled conditions using nonradioactive tracers

    International Nuclear Information System (INIS)

    Gustafsson, E.; Klockars, C.-E.

    1981-04-01

    The purpose of the investigation has been study the following parameters along existing fractures between two boreholes: hydraulic properties of rock mass and fractures; adsorptive properties of some selected tracers during transport along fractures; dispersivity and dilution of tracers during transport in fractures; kinematic porosity of fractured bedrock. The procedure has been to determine the hydraulic properties of a rock mass by means of conventional hydraulic testing methods in 100 m deep boreholes, and to study transport mechanisms and properties of selected tracers in a selected fracture zone between two boreholes. (Auth.)

  18. Thiocyanate use as radioactive tracer in a petroleum field

    International Nuclear Information System (INIS)

    Pereira, Elaine Henriques Teixeira; Souza, Fabiane Ferreira de; Pinto, Amenonia Maria Ferreira; Moreira, Rubens Martins

    2002-01-01

    Currently, most of the oil exploration in reservoirs is made out if the assistance of the injection of different fluids, waters in particular, to increase production. For this reason it has been largely spread the application of chemical and/or radioactive tracers in the study of the characteristics of transport of the injected fluid between injection and production wells. K 35 SCN is considered a good tracer due to its higher solubility in water and low adsorption. This work presents a brief review of the methods described in literature for obtain S-35. It was found out to be the most appropriate method the synthesis of thiocyanate starting from the reaction of KCN and S-35. It was also investigated the efficiency of the reaction for the obtention of KSCN. (author)

  19. 8th International Conference on Partial Least Squares and Related Methods

    CERN Document Server

    Vinzi, Vincenzo; Russolillo, Giorgio; Saporta, Gilbert; Trinchera, Laura

    2016-01-01

    This volume presents state of the art theories, new developments, and important applications of Partial Least Square (PLS) methods. The text begins with the invited communications of current leaders in the field who cover the history of PLS, an overview of methodological issues, and recent advances in regression and multi-block approaches. The rest of the volume comprises selected, reviewed contributions from the 8th International Conference on Partial Least Squares and Related Methods held in Paris, France, on 26-28 May, 2014. They are organized in four coherent sections: 1) new developments in genomics and brain imaging, 2) new and alternative methods for multi-table and path analysis, 3) advances in partial least square regression (PLSR), and 4) partial least square path modeling (PLS-PM) breakthroughs and applications. PLS methods are very versatile methods that are now used in areas as diverse as engineering, life science, sociology, psychology, brain imaging, genomics, and business among both academics ...

  20. 13th International Conference on Integral Methods in Science and Engineering

    CERN Document Server

    Kirsch, Andreas

    2015-01-01

    This contributed volume contains a collection of articles on state-of-the-art developments on the construction of theoretical integral techniques and their application to specific problems in science and engineering.  Written by internationally recognized researchers, the chapters in this book are based on talks given at the Thirteenth International Conference on Integral Methods in Science and Engineering, held July 21–25, 2014, in Karlsruhe, Germany.   A broad range of topics is addressed, from problems of existence and uniqueness for singular integral equations on domain boundaries to numerical integration via finite and boundary elements, conservation laws, hybrid methods, and other quadrature-related approaches.   This collection will be of interest to researchers in applied mathematics, physics, and mechanical and electrical engineering, as well as graduate students in these disciplines and other professionals for whom integration is an essential tool.

  1. Full 3D internal strain measurement for device packaging materials using synchrotron laminography and volumetric digital image correlation method

    International Nuclear Information System (INIS)

    Asada, Takashi; Kimura, Hidehiko; Yamaguchi, Satoshi; Kano, Taiki; Kajiwara, Kentaro

    2014-01-01

    In order to measure full 3D internal strain field of resin molding compound specimens, synchrotron computed tomography and laminography at SPring-8 were performed. Then the reconstructed images were applied to 3D digital image correlation method to compute internal strain field. The results showed that internal strains in resin molding compound could be visualized in this way. (author)

  2. Proceedings of the 1st international scientific conference "Teaching methods for economics and business sciences"

    OpenAIRE

    2017-01-01

    Teaching is a challenging but also a rewarding profession. It is underpinned by one key question: how do we build a good teaching and learning environment so that our students can acquire professional competences which will enable them to be successful in today’s global business environment. These proceedings include the papers presented at the 1st International Scientific Conference »Teaching Methods for Economics and Business Sciences« held on 8 May 2017 at the University of Maribor, F...

  3. Method for operating a spark-ignition, direct-injection internal combustion engine

    Science.gov (United States)

    Narayanaswamy, Kushal; Koch, Calvin K.; Najt, Paul M.; Szekely, Jr., Gerald A.; Toner, Joel G.

    2015-06-02

    A spark-ignition, direct-injection internal combustion engine is coupled to an exhaust aftertreatment system including a three-way catalytic converter upstream of an NH3-SCR catalyst. A method for operating the engine includes operating the engine in a fuel cutoff mode and coincidentally executing a second fuel injection control scheme upon detecting an engine load that permits operation in the fuel cutoff mode.

  4. Asteroseismic modelling of solar-type stars: internal systematics from input physics and surface correction methods

    Science.gov (United States)

    Nsamba, B.; Campante, T. L.; Monteiro, M. J. P. F. G.; Cunha, M. S.; Rendle, B. M.; Reese, D. R.; Verma, K.

    2018-04-01

    Asteroseismic forward modelling techniques are being used to determine fundamental properties (e.g. mass, radius, and age) of solar-type stars. The need to take into account all possible sources of error is of paramount importance towards a robust determination of stellar properties. We present a study of 34 solar-type stars for which high signal-to-noise asteroseismic data is available from multi-year Kepler photometry. We explore the internal systematics on the stellar properties, that is, associated with the uncertainty in the input physics used to construct the stellar models. In particular, we explore the systematics arising from: (i) the inclusion of the diffusion of helium and heavy elements; and (ii) the uncertainty in solar metallicity mixture. We also assess the systematics arising from (iii) different surface correction methods used in optimisation/fitting procedures. The systematics arising from comparing results of models with and without diffusion are found to be 0.5%, 0.8%, 2.1%, and 16% in mean density, radius, mass, and age, respectively. The internal systematics in age are significantly larger than the statistical uncertainties. We find the internal systematics resulting from the uncertainty in solar metallicity mixture to be 0.7% in mean density, 0.5% in radius, 1.4% in mass, and 6.7% in age. The surface correction method by Sonoi et al. and Ball & Gizon's two-term correction produce the lowest internal systematics among the different correction methods, namely, ˜1%, ˜1%, ˜2%, and ˜8% in mean density, radius, mass, and age, respectively. Stellar masses obtained using the surface correction methods by Kjeldsen et al. and Ball & Gizon's one-term correction are systematically higher than those obtained using frequency ratios.

  5. The accurate particle tracer code

    Science.gov (United States)

    Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi; Yao, Yicun

    2017-11-01

    The Accurate Particle Tracer (APT) code is designed for systematic large-scale applications of geometric algorithms for particle dynamical simulations. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and nonlinear problems. To provide a flexible and convenient I/O interface, the libraries of Lua and Hdf5 are used. Following a three-step procedure, users can efficiently extend the libraries of electromagnetic configurations, external non-electromagnetic forces, particle pushers, and initialization approaches by use of the extendible module. APT has been used in simulations of key physical problems, such as runaway electrons in tokamaks and energetic particles in Van Allen belt. As an important realization, the APT-SW version has been successfully distributed on the world's fastest computer, the Sunway TaihuLight supercomputer, by supporting master-slave architecture of Sunway many-core processors. Based on large-scale simulations of a runaway beam under parameters of the ITER tokamak, it is revealed that the magnetic ripple field can disperse the pitch-angle distribution significantly and improve the confinement of energetic runaway beam on the same time.

  6. Development of Radioisotope Tracer Technology

    International Nuclear Information System (INIS)

    Jung, Sung Hee; Jin, Joon Ha; Kim, Jong Bum; Kim, Jin Seop; Kim, Jae Jo; Park, Soon Chul; Lim, Don Soon; Choi, Byung Jong; Jang, Dong Soon; Kim, Hye Sook

    2007-06-01

    The project is aimed to develop the radiotracer technology for process optimization and trouble-shooting to establish the environmental and industrial application of radiation and radioisotopes. The advanced equipment and software such as high speed data acquisition system, RTD model and high pressure injection tool have developed. Based on the various field application to the refinery/petrochemical industries, the developed technology was transfer to NDT company for commercial service. For the environmental application of radiotracer technology, injector, detector sled, core sampler, RI and GPS data logging system are developed and field tests were implemented successfully at Wolsung and Haeundae beach. Additionally tracer technology were also used for the performance test of the clarifier in a wastewater treatment plant and for the leak detection in reservoirs. From the experience of case studies on radiotracer experiment in waste water treatment facilities, 'The New Excellent Technology' is granted from the ministry of environment. For future technology, preliminary research for industrial gamma transmission and emission tomography which are new technology combined with radioisotope and image reconstruction are carried out

  7. Compartmental modeling and tracer kinetics

    CERN Document Server

    Anderson, David H

    1983-01-01

    This monograph is concerned with mathematical aspects of compartmental an­ alysis. In particular, linear models are closely analyzed since they are fully justifiable as an investigative tool in tracer experiments. The objective of the monograph is to bring the reader up to date on some of the current mathematical prob­ lems of interest in compartmental analysis. This is accomplished by reviewing mathematical developments in the literature, especially over the last 10-15 years, and by presenting some new thoughts and directions for future mathematical research. These notes started as a series of lectures that I gave while visiting with the Division of Applied ~1athematics, Brown University, 1979, and have developed in­ to this collection of articles aimed at the reader with a beginning graduate level background in mathematics. The text can be used as a self-paced reading course. With this in mind, exercises have been appropriately placed throughout the notes. As an aid in reading the material, the e~d of a ...

  8. PC-based hardware and software for tracer measurements

    International Nuclear Information System (INIS)

    Kaemaeraeinen, V.J.; Kall, Leif; Kaeki, Arvo

    1990-01-01

    Cheap, efficient personal computers can be used for both measurement and analysis. The results can be calculated immediately after the measurements are made in order to exploit the real-time measuring capabilities of tracer techniques fully. In the analysis phase the measurement information is visualized using graphical methods. The programs are menu drive to make them easy to use and adaptable for field conditions. The measuring equipment is modular for easy installation and maintenance. (author)

  9. The importance of tracer technology in combined borehole investigations

    International Nuclear Information System (INIS)

    Zojer, H.

    1998-01-01

    In an experimental field for a waste disposal site, investigations have been carried out applying methods from geology, hydrology hydrogeology, hydrochemistry, environmental isotope hydrology and tracer technology. All data obtained result to a dynamic drainage model of groundwater. The combined interpretation of borehole data guarantees a high-grade knowledge of groundwater exfiltrating to the surface drainage, which enables proper control measures of the disposal site and an effective groundwater protection. (author)

  10. The Topology Optimization of Three-dimensional Cooling Fins by the Internal Element Connectivity Parameterization Method

    International Nuclear Information System (INIS)

    Yoo, Sung Min; Kim, Yoon Young

    2007-01-01

    This work is concerned with the topology optimization of three-dimensional cooling fins or heat sinks. Motivated by earlier success of the Internal Element Connectivity Method (I-ECP) method in two dimensional problems, the extension of I-ECP to three-dimensional problems is carried out. The main efforts were made to maintain the numerical trouble-free characteristics of I-ECP for full three-dimensional problems; a serious numerical problem appearing in thermal topology optimization is erroneous temperature undershooting. The effectiveness of the present implementation was checked through the design optimization of three-dimensional fins

  11. Current Methods Applied to Biomaterials - Characterization Approaches, Safety Assessment and Biological International Standards.

    Science.gov (United States)

    Oliveira, Justine P R; Ortiz, H Ivan Melendez; Bucio, Emilio; Alves, Patricia Terra; Lima, Mayara Ingrid Sousa; Goulart, Luiz Ricardo; Mathor, Monica B; Varca, Gustavo H C; Lugao, Ademar B

    2018-04-10

    Safety and biocompatibility assessment of biomaterials are themes of constant concern as advanced materials enter the market as well as products manufactured by new techniques emerge. Within this context, this review provides an up-to-date approach on current methods for the characterization and safety assessment of biomaterials and biomedical devices from a physicalchemical to a biological perspective, including a description of the alternative methods in accordance with current and established international standards. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Undergraduate prosthetics and orthotics teaching methods: A baseline for international comparison.

    Science.gov (United States)

    Aminian, Gholamreza; O'Toole, John M; Mehraban, Afsoon Hassani

    2015-08-01

    Education of Prosthetics and Orthotics is a relatively recent professional program. While there has been some work on various teaching methods and strategies in international medical education, limited publication exists within prosthetics and orthotics. To identify the teaching and learning methods that are used in Bachelor-level prosthetics and orthotics programs that are given highest priority by expert prosthetics and orthotics instructors from regions enjoying a range of economic development. Mixed method. The study partly documented by this article utilized a mixed method approach (qualitative and quantitative methods) within which each phase provided data for other phases. It began with analysis of prosthetics and orthotics curricula documents, which was followed by a broad survey of instructors in this field and then a modified Delphi process. The expert instructors who participated in this study gave high priority to student-centered, small group methods that encourage critical thinking and may lead to lifelong learning. Instructors from more developed nations placed higher priority on student's independent acquisition of prosthetics and orthotics knowledge, particularly in clinical training. Application of student-centered approaches to prosthetics and orthotics programs may be preferred by many experts, but there appeared to be regional differences in the priority given to different teaching methods. The results of this study identify the methods of teaching that are preferred by expert prosthetics and orthotics instructors from a variety of regions. This treatment of current instructional techniques may inform instructor choice of teaching methods that impact the quality of education and improve the professional skills of students. © The International Society for Prosthetics and Orthotics 2014.

  13. Normalization method for metabolomics data using optimal selection of multiple internal standards

    Directory of Open Access Journals (Sweden)

    Yetukuri Laxman

    2007-03-01

    Full Text Available Abstract Background Success of metabolomics as the phenotyping platform largely depends on its ability to detect various sources of biological variability. Removal of platform-specific sources of variability such as systematic error is therefore one of the foremost priorities in data preprocessing. However, chemical diversity of molecular species included in typical metabolic profiling experiments leads to different responses to variations in experimental conditions, making normalization a very demanding task. Results With the aim to remove unwanted systematic variation, we present an approach that utilizes variability information from multiple internal standard compounds to find optimal normalization factor for each individual molecular species detected by metabolomics approach (NOMIS. We demonstrate the method on mouse liver lipidomic profiles using Ultra Performance Liquid Chromatography coupled to high resolution mass spectrometry, and compare its performance to two commonly utilized normalization methods: normalization by l2 norm and by retention time region specific standard compound profiles. The NOMIS method proved superior in its ability to reduce the effect of systematic error across the full spectrum of metabolite peaks. We also demonstrate that the method can be used to select best combinations of standard compounds for normalization. Conclusion Depending on experiment design and biological matrix, the NOMIS method is applicable either as a one-step normalization method or as a two-step method where the normalization parameters, influenced by variabilities of internal standard compounds and their correlation to metabolites, are first calculated from a study conducted in repeatability conditions. The method can also be used in analytical development of metabolomics methods by helping to select best combinations of standard compounds for a particular biological matrix and analytical platform.

  14. Combining tracer flux ratio methodology with low-flying aircraft measurements to estimate dairy farm CH4 emissions

    Science.gov (United States)

    Daube, C.; Conley, S.; Faloona, I. C.; Yacovitch, T. I.; Roscioli, J. R.; Morris, M.; Curry, J.; Arndt, C.; Herndon, S. C.

    2017-12-01

    Livestock activity, enteric fermentation of feed and anaerobic digestion of waste, contributes significantly to the methane budget of the United States (EPA, 2016). Studies question the reported magnitude of these methane sources (Miller et. al., 2013), calling for more detailed research of agricultural animals (Hristov, 2014). Tracer flux ratio is an attractive experimental method to bring to this problem because it does not rely on estimates of atmospheric dispersion. Collection of data occurred during one week at two dairy farms in central California (June, 2016). Each farm varied in size, layout, head count, and general operation. The tracer flux ratio method involves releasing ethane on-site with a known flow rate to serve as a tracer gas. Downwind mixed enhancements in ethane (from the tracer) and methane (from the dairy) were measured, and their ratio used to infer the unknown methane emission rate from the farm. An instrumented van drove transects downwind of each farm on public roads while tracer gases were released on-site, employing the tracer flux ratio methodology to assess simultaneous methane and tracer gas plumes. Flying circles around each farm, a small instrumented aircraft made measurements to perform a mass balance evaluation of methane gas. In the course of these two different methane quantification techniques, we were able to validate yet a third method: tracer flux ratio measured via aircraft. Ground-based tracer release rates were applied to the aircraft-observed methane-to-ethane ratios, yielding whole-site methane emission rates. Never before has the tracer flux ratio method been executed with aircraft measurements. Estimates from this new application closely resemble results from the standard ground-based technique to within their respective uncertainties. Incorporating this new dimension to the tracer flux ratio methodology provides additional context for local plume dynamics and validation of both ground and flight-based data.

  15. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  16. Copper ion as a new leakage tracer.

    Science.gov (United States)

    Modaresi, J; Baharizade, M; Shareghi, A; Ahmadi, M; Daneshkazemi, A

    2013-12-01

    Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal. Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method. The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope. The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods. Based on our results, there was no significant correlation between the dye penetration and the copper ion diffusion methods.

  17. Tracer surface diffusion on UO2

    International Nuclear Information System (INIS)

    Zhou, S.Y.; Olander, D.R.

    1983-06-01

    Surface diffusion on UO 2 was measured by the spreading of U-234 tracer on the surface of a duplex diffusion couple consisting of wafers of depleted and enriched UO 2 joined by a bond of uranium metal

  18. The field tracer test study of atmospheric dispersion in Fujian Huian Nuclear Power Plant site

    International Nuclear Information System (INIS)

    Hu Erbang; Xin Cuntian; Yan Jiangyu; Ren Zhiqiang; Xuan Yiren; Jia Peirong

    2003-01-01

    The SF 6 tracer tests and its main results completed in site of Fujian Huian Nuclear Power Plant during summer, 2002, are described. A total of 15 times of SF 6 tracer tests were done in the July, in which the time of atmospheric stability B, C, D, E is respectively 3, 2, 9, 1 based on ΔT-U method and the time of B, D, E is respectively 1, 11, 3 based on ΔT method. About 50 samples were collected in each SF 6 tracer tests, the maximum of sample distance from the tower in which the SF 6 tracer was released is about 15 km. The values of p y , p z , q y , q z in the formula of diffusion parameters is determined. Finally the above diffusion parameters are compared with P-G curve, Briggs diffusion parameters and those obtained from turbulence observation and wind tunnel simulation test done in the past time. (authors)

  19. An Investigation of the Variety and Complexity of Statistical Methods Used in Current Internal Medicine Literature.

    Science.gov (United States)

    Narayanan, Roshni; Nugent, Rebecca; Nugent, Kenneth

    2015-10-01

    Accreditation Council for Graduate Medical Education guidelines require internal medicine residents to develop skills in the interpretation of medical literature and to understand the principles of research. A necessary component is the ability to understand the statistical methods used and their results, material that is not an in-depth focus of most medical school curricula and residency programs. Given the breadth and depth of the current medical literature and an increasing emphasis on complex, sophisticated statistical analyses, the statistical foundation and education necessary for residents are uncertain. We reviewed the statistical methods and terms used in 49 articles discussed at the journal club in the Department of Internal Medicine residency program at Texas Tech University between January 1, 2013 and June 30, 2013. We collected information on the study type and on the statistical methods used for summarizing and comparing samples, determining the relations between independent variables and dependent variables, and estimating models. We then identified the typical statistics education level at which each term or method is learned. A total of 14 articles came from the Journal of the American Medical Association Internal Medicine, 11 from the New England Journal of Medicine, 6 from the Annals of Internal Medicine, 5 from the Journal of the American Medical Association, and 13 from other journals. Twenty reported randomized controlled trials. Summary statistics included mean values (39 articles), category counts (38), and medians (28). Group comparisons were based on t tests (14 articles), χ2 tests (21), and nonparametric ranking tests (10). The relations between dependent and independent variables were analyzed with simple regression (6 articles), multivariate regression (11), and logistic regression (8). Nine studies reported odds ratios with 95% confidence intervals, and seven analyzed test performance using sensitivity and specificity calculations

  20. Tracer techniques for urine volume determination and urine collection and sampling back-up system

    Science.gov (United States)

    Ramirez, R. V.

    1971-01-01

    The feasibility, functionality, and overall accuracy of the use of lithium were investigated as a chemical tracer in urine for providing a means of indirect determination of total urine volume by the atomic absorption spectrophotometry method. Experiments were conducted to investigate the parameters of instrumentation, tracer concentration, mixing times, and methods for incorporating the tracer material in the urine collection bag, and to refine and optimize the urine tracer technique to comply with the Skylab scheme and operational parameters of + or - 2% of volume error and + or - 1% accuracy of amount of tracer added to each container. In addition, a back-up method for urine collection and sampling system was developed and evaluated. This back-up method incorporates the tracer technique for volume determination in event of failure of the primary urine collection and preservation system. One chemical preservative was selected and evaluated as a contingency chemical preservative for the storage of urine in event of failure of the urine cooling system.

  1. Radioisotope tracers in industrial flow studies

    International Nuclear Information System (INIS)

    Easey, J.F.

    1987-01-01

    The scope of radioisotope tracer work carried out by ANSTO has involved most sectors of Australian industry including iron and steel coal, chemical, petrochemical, natural gas, metallurgical, mineral, power generation, liquified air plant, as well as port authorities, water and sewerage instrumentalities, and environmental agencies. A major class of such studies concerns itself with flow and wear studies involving industrial equipment. Some examples are discussed which illustrate the utility of radioisotope tracer techniques in these applications

  2. Spatial variability of mixing ratios of ammonia and tracer gases in a naturally ventilated dairy cow barn

    NARCIS (Netherlands)

    Mendes, Luciano B.; Edouard, Nadège; Ogink, Nico W.M.; Dooren, van Hendrik Jan C.; Fátima F. TinÔco, de Ilda; Mosquera Losada, Julio

    2015-01-01

    The use of the tracer gas ratio method to estimate emissions from naturally ventilated (NV) livestock barns excludes the need of monitoring ventilation rates. However, it requires accurate measurement of tracer release rate (QT) and a representative estimate of the mixing ratio between

  3. Improving Marine Ecosystem Models with Biochemical Tracers

    Science.gov (United States)

    Pethybridge, Heidi R.; Choy, C. Anela; Polovina, Jeffrey J.; Fulton, Elizabeth A.

    2018-01-01

    Empirical data on food web dynamics and predator-prey interactions underpin ecosystem models, which are increasingly used to support strategic management of marine resources. These data have traditionally derived from stomach content analysis, but new and complementary forms of ecological data are increasingly available from biochemical tracer techniques. Extensive opportunities exist to improve the empirical robustness of ecosystem models through the incorporation of biochemical tracer data and derived indices, an area that is rapidly expanding because of advances in analytical developments and sophisticated statistical techniques. Here, we explore the trophic information required by ecosystem model frameworks (species, individual, and size based) and match them to the most commonly used biochemical tracers (bulk tissue and compound-specific stable isotopes, fatty acids, and trace elements). Key quantitative parameters derived from biochemical tracers include estimates of diet composition, niche width, and trophic position. Biochemical tracers also provide powerful insight into the spatial and temporal variability of food web structure and the characterization of dominant basal and microbial food web groups. A major challenge in incorporating biochemical tracer data into ecosystem models is scale and data type mismatches, which can be overcome with greater knowledge exchange and numerical approaches that transform, integrate, and visualize data.

  4. [Evaluation method with radiographic image quality indicator for internal defects of dental casting metallic restoration].

    Science.gov (United States)

    Li, Y; Zheng, G; Lin, H

    2014-12-18

    To develop a new kind of dental radiographic image quality indicator (IQI) for internal quality of casting metallic restoration to influence on its usage life. Radiographic image quality indicator method was used to evaluate the depth of the defects region and internal quality of 127 casting metallic restoration and the accuracy was compared with that of conventional callipers method. In the 127 cases of casting metallic restoration, 9 were found the thickness less than 0.7 mm and the thinnest thickness only 0.2 mm in 26 casting metallic crowns or bridges' occlusal defects region. The data measured by image quality indicator were consistent with those measured by conventional gauging. Two metal inner crowns were found the thickness less than 0.3 mm in 56 porcelain crowns or bridges. The thickness of casting removable partial denture was more than 1.0 mm, but thinner regions were not found. It was found that in a titanium partial denture, the X-ray image of clasp was not uniform and there were internal porosity defects in the clasp. Special dental image quality indicator can solve the visual error problems caused by different observing backgrounds and estimate the depth of the defects region in the casting.

  5. 7th International Workshop on Meshfree Methods for Partial Differential Equations

    CERN Document Server

    Schweitzer, Marc

    2015-01-01

    Meshfree methods, particle methods, and generalized finite element methods have witnessed substantial development since the mid 1990s. The growing interest in these methods is due in part to the fact that they are extremely flexible numerical tools and can be interpreted in a number of ways. For instance, meshfree methods can be viewed as a natural extension of classical finite element and finite difference methods to scattered node configurations with no fixed connectivity. Furthermore, meshfree methods offer a number of advantageous features which are especially attractive when dealing with multiscale phenomena: a priori knowledge about particular local behavior of the solution can easily be introduced in the meshfree approximation space, and coarse-scale approximations can be seamlessly refined with fine-scale information. This volume collects selected papers presented at the Seventh International Workshop on Meshfree Methods, held in Bonn, Germany in September 2013. They address various aspec...

  6. Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills

    International Nuclear Information System (INIS)

    Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan; Chiu, Pei; Yazdani, Ramin; Imhoff, Paul T.

    2012-01-01

    Highlights: ► Photoacoustic infrared spectroscopy tested for measuring tracer gas in landfills. ► Measurement errors for tracer gases were 1–3% in landfill gas. ► Background signals from landfill gas result in elevated limits of detection. ► Technique is much less expensive and easier to use than GC. - Abstract: Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobility and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF 6 ), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1–3% in landfill gas but 4–5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3–4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences.

  7. Fluid-Induced Vibration Analysis for Reactor Internals Using Computational FSI Method

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jong Sung; Yi, Kun Woo; Sung, Ki Kwang; Im, In Young; Choi, Taek Sang [KEPCO E and C, Daejeon (Korea, Republic of)

    2013-10-15

    This paper introduces a fluid-induced vibration analysis method which calculates the response of the RVI to both deterministic and random loads at once and utilizes more realistic pressure distribution using the computational Fluid Structure Interaction (FSI) method. As addressed above, the FIV analysis for the RVI was carried out using the computational FSI method. This method calculates the response to deterministic and random turbulence loads at once. This method is also a simple and integrative method to get structural dynamic responses of reactor internals to various flow-induced loads. Because the analysis of this paper omitted the bypass flow region and Inner Barrel Assembly (IBA) due to the limitation of computer resources, it is necessary to find an effective way to consider all regions in the RV for the FIV analysis in the future. Reactor coolant flow makes Reactor Vessel Internals (RVI) vibrate and may affect the structural integrity of them. U. S. NRC Regulatory Guide 1.20 requires the Comprehensive Vibration Assessment Program (CVAP) to verify the structural integrity of the RVI for Fluid-Induced Vibration (FIV). The hydraulic forces on the RVI of OPR1000 and APR1400 were computed from the hydraulic formulas and the CVAP measurements in Palo Verde Unit 1 and Yonggwang Unit 4 for the structural vibration analyses. In this method, the hydraulic forces were divided into deterministic and random turbulence loads and were used for the excitation forces of the separate structural analyses. These forces are applied to the finite element model and the responses to them were combined into the resultant stresses.

  8. Scintigraphy of inflammation with nanometer-sixed colloidal tracers

    International Nuclear Information System (INIS)

    De Schrijver, M.

    1989-01-01

    This book describes a novel approach to the scintigraphy of inflammatory processes of the extremities. It presents a method specially developed to bring this diagnostic modality whithin the reach of every nuclear medicine centre without requiring a special infrastructure or extensively trained personnel. The author revieuws the existing nuclear medicine techniques and critically analyses their relative advantages and pitfalls before proceeding to a detailed account of the use of a colloidal tracer for detecting and monitoring inflammation. The author identifies the pathophysiological basis of his concept and gives extensive preclinical data prior to discussing a number of comparative clinical studies with the new technique. Additional benefits are brought by the book's emphasis on the importance of a solid radiopharmacological foundation to the medically used tracers and demonstrates with a few suprising examples how shortcomings at this level may lead to misleading findings in the daily practive of nuclear medicine, even with routinely used radiopharmaceuticals. (author). refs.; figs.; tabs

  9. In-situ fracture mapping using geotomography and brine tracers

    International Nuclear Information System (INIS)

    Deadrick, F.J.; Ramirez, A.L.; Lytle, R.J.

    1981-01-01

    The Lawrence Livermore National Laboratory is currently assessing the capabilities of high resolution geophysical methods to characterize geologic sites for the disposal of high level nuclear waste. A successful experiment has recently been performed in which salt water tracers and high frequency electromagnetic waves were utilized to map rock mass fracture zones in-situ. Multiple cross-borehole EM transmissions were used to generate a tomographic image of the fractured rock region between two boreholes. The tomographs obtained correlate well with conventional wireline geophysical logs which can be used to infer the location of fractured zones in the rock mass. This indirect data suggests that the geotomography and brine tracer technique may have merit in mapping fractured zones between boreholes

  10. PREFACE: I International Scientific School Methods of Digital Image Processing in Optics and Photonics

    Science.gov (United States)

    Gurov, I. P.; Kozlov, S. A.

    2014-09-01

    The first international scientific school "Methods of Digital Image Processing in Optics and Photonics" was held with a view to develop cooperation between world-class experts, young scientists, students and post-graduate students, and to exchange information on the current status and directions of research in the field of digital image processing in optics and photonics. The International Scientific School was managed by: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) - Saint Petersburg (Russia) Chernyshevsky Saratov State University - Saratov (Russia) National research nuclear University "MEPHI" (NRNU MEPhI) - Moscow (Russia) The school was held with the participation of the local chapters of Optical Society of America (OSA), the Society of Photo-Optical Instrumentation Engineers (SPIE) and IEEE Photonics Society. Further details, including topics, committees and conference photos are available in the PDF

  11. International Conference on Modern Mathematical Methods and High Performance Computing in Science and Technology

    CERN Document Server

    Srivastava, HM; Venturino, Ezio; Resch, Michael; Gupta, Vijay

    2016-01-01

    The book discusses important results in modern mathematical models and high performance computing, such as applied operations research, simulation of operations, statistical modeling and applications, invisibility regions and regular meta-materials, unmanned vehicles, modern radar techniques/SAR imaging, satellite remote sensing, coding, and robotic systems. Furthermore, it is valuable as a reference work and as a basis for further study and research. All contributing authors are respected academicians, scientists and researchers from around the globe. All the papers were presented at the international conference on Modern Mathematical Methods and High Performance Computing in Science & Technology (M3HPCST 2015), held at Raj Kumar Goel Institute of Technology, Ghaziabad, India, from 27–29 December 2015, and peer-reviewed by international experts. The conference provided an exceptional platform for leading researchers, academicians, developers, engineers and technocrats from a broad range of disciplines ...

  12. Quantitative measurement of maritime sediment movement using radioactive tracers

    International Nuclear Information System (INIS)

    Makovski, E.; Grissener, G.

    1967-01-01

    The quantitative method described in the paper involves burying appropriate detectors over a given area of the sea bottom, the detectors being connected to recording equipment which is itself buried in the sediment or situated on the shore. Detectors arranged in this way are covered by a certain layer of radioactive sediment whose activity is proportional to its mass. Before the labelled sediments are removed, their initial activity is measured, and then, as the covering is removed, measurements are made of the gradual decrease in activity corresponding to loss of the surface layer of the bottom deposit area under investigation, expressed in g/cm 2 . The tracers used in the investigations discussed were natural ones such as sea with 31 Si and artificial ones such as activated fragments of sodium glass (with a 6.5% admixture of Fe 2 O 3 ) with 24 Na . The proportional dependence of activity on mass has been confirmed for both tracers; this is an essential point for a tracer intended for quantitative measurements. This proportionality is very well maintained if a sample of highly active sediment is introduced into a large mass of inactive sediments (10 -2 - 10 -3 ). The concluding section describes the advantages of this method as a possible way of using radioisotopes with a short half-life and a low total activity of the order of a few millicuries. (author)

  13. Methods of Raising Funds for Purchasing of New Cruise Ships by International Corporations

    Directory of Open Access Journals (Sweden)

    Kizielewicz Joanna

    2017-06-01

    Full Text Available The world’s cruise corporations regularly purchase large, luxurious cruise ships. In accordance with the Cruise Line International Association, 33 new ocean cruise ships will be available on the market by 2020. These types of capital expenditures are associated with large financial outlays of up to $ 1 billion. The leading cruise corporations are not able to finance purchases of new units with their own resources and therefore look for different solutions. Available publications focus mainly on issues related to purchasing cargo ships, not cruise ships. The objective of the article is to identify sources of funding of new cruise ships. Our analysis identifies the average capital expenditure associated with purchasing new cruise ships and factors that influence it. The most popular methods for raising such capital are also provided. Our research methodology relies on data exploration method, a desk research method and comparative analysis.

  14. IV international conference on computational methods in marine engineering : selected papers

    CERN Document Server

    Oñate, Eugenio; García-Espinosa, Julio; Kvamsdal, Trond; Bergan, Pål; MARINE 2011

    2013-01-01

    This book contains selected papers from the Fourth International Conference on Computational Methods in Marine Engineering, held at Instituto Superior Técnico, Technical University of Lisbon, Portugal in September 2011.  Nowadays, computational methods are an essential tool of engineering, which includes a major field of interest in marine applications, such as the maritime and offshore industries and engineering challenges related to the marine environment and renewable energies. The 2011 Conference included 8 invited plenary lectures and 86 presentations distributed through 10 thematic sessions that covered many of the most relevant topics of marine engineering today. This book contains 16 selected papers from the Conference that cover “CFD for Offshore Applications”, “Fluid-Structure Interaction”, “Isogeometric Methods for Marine Engineering”, “Marine/Offshore Renewable Energy”, “Maneuvering and Seakeeping”, “Propulsion and Cavitation” and “Ship Hydrodynamics”.  The papers we...

  15. Innovative Calibration Method for System Level Simulation Models of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Ivo Prah

    2016-09-01

    Full Text Available The paper outlines a procedure for the computer-controlled calibration of the combined zero-dimensional (0D and one-dimensional (1D thermodynamic simulation model of a turbocharged internal combustion engine (ICE. The main purpose of the calibration is to determine input parameters of the simulation model in such a way as to achieve the smallest difference between the results of the measurements and the results of the numerical simulations with minimum consumption of the computing time. An innovative calibration methodology is based on a novel interaction between optimization methods and physically based methods of the selected ICE sub-systems. Therein physically based methods were used for steering the division of the integral ICE to several sub-models and for determining parameters of selected components considering their governing equations. Innovative multistage interaction between optimization methods and physically based methods allows, unlike the use of well-established methods that rely only on the optimization techniques, for successful calibration of a large number of input parameters with low time consumption. Therefore, the proposed method is suitable for efficient calibration of simulation models of advanced ICEs.

  16. International meeting 'Selected topics on nuclear methods for non-nuclear applications'. Proceedings

    International Nuclear Information System (INIS)

    Stoyanov, Ch.

    2007-01-01

    The volume includes the presentations given on the International Meeting 'Selected Topics on Nuclear Methods for Non-nuclear Applications'. The meeting was organized by the Project CECOA. The Project 'CEnter for COoerative Activities' (CECOA) of the Institute for Nuclear Research and Nuclear Energy (INRNE) of Bulgarian Academy of Sciences is part of the Program 'Creating of Infrastructure' of Bulgarian Ministry of Science and Education. The CECOA-project unifies the groups of INRNE doing research in the field of nuclear methods. Four Laboratories of INRNE are members of CECOA-project: Moessbauer Spectroscopy and Low Radioactivity Measurements, High-Resolution Gamma-Spectroscopy, Neutron Methods in Condensed Matter, Neutron Optics and Structure Analysis. Taking into account the leading role of education on nuclear physics the Project includes program devoted to the training on nuclear physics. The presented volume contains 23 contributed papers. The contributions are separated in 6 sections. The section 'Nano technology' includes 5 papers. The activity in this field within the Project reveals the collaboration with other Institutes of Bulgarian Academy of Sciences as well as large international contacts. The section 'Radioecology and Radioactive Waste' is two fold. Part of the contributions of the section manifests the connection of the CECOA with small enterprises. The contacts are on the level of common projects concerning the investigations, remediation and release of radioactively contaminated terrain, soils, water, buildings and materials around the former uranium processing industry. Another part of the section is devoted to the application of nuclear methods to the treatment of radioactive waste produced by nuclear power stations. The section 'Neutron Physics' reveals the activity within the Project connected with the study of new materials using polarized neutrons and neutron diffraction methods. The section 'Nuclear Physics' is an introduction to some

  17. The QAP weighted network analysis method and its application in international services trade

    Science.gov (United States)

    Xu, Helian; Cheng, Long

    2016-04-01

    Based on QAP (Quadratic Assignment Procedure) correlation and complex network theory, this paper puts forward a new method named QAP Weighted Network Analysis Method. The core idea of the method is to analyze influences among relations in a social or economic group by building a QAP weighted network of networks of relations. In the QAP weighted network, a node depicts a relation and an undirect edge exists between any pair of nodes if there is significant correlation between relations. As an application of the QAP weighted network, we study international services trade by using the QAP weighted network, in which nodes depict 10 kinds of services trade relations. After the analysis of international services trade by QAP weighted network, and by using distance indicators, hierarchy tree and minimum spanning tree, the conclusion shows that: Firstly, significant correlation exists in all services trade, and the development of any one service trade will stimulate the other nine. Secondly, as the economic globalization goes deeper, correlations in all services trade have been strengthened continually, and clustering effects exist in those services trade. Thirdly, transportation services trade, computer and information services trade and communication services trade have the most influence and are at the core in all services trade.

  18. Process Analysis in Chemical Plant by Means of Radioactive Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Hamada, K.; Osada, K. [Showa Denko K.K., Tokyo (Japan)

    1967-06-15

    Following the movement of solids and fluids is important in chemical processes to determine mixing efficiency and residence time. Since it is necessary to follow many complex substances such as raw materials, intermediates and reactants in plant investigations, it is often necessary to ascertain whether the behaviour of the radioisotope tracer and the substance to be traced are identical. The most difficult problem is to determine the best method of labelling, a factor which is a substantial key to the success of an experiment. Usually, there are three labelling techniques: radioisotope labelling, pre-.activation of the material and post-activation of the material. This paper deals with practical examples of the double-tracer technique, a combination of conventional radioisotope labelling and post-activation methods by means of activation analysis. In process analysis by means of tracers, a practical measurement method should also be devised and developed for each experiment. Phosphorus-32 and gold (non-radioactive) were used to measure retention time in a carbon-black plant. The radioisotope was pumped into a feed-stock pipe positioned before the reactor and samples were taken from each process of the plant, including the bag filter, mixer and product tank. After sampling from each step of the process, {sup 32}P in a semi-infinite powder sample was measured in situ by beta counting, and the gold was measured by gamma counting after activating the sample in a reactor. The experiment showed that both tracers had the same residence time, which was shorter than expected. Useful data were also obtained from the dispersion pattern of the material flow for future operation controls, including the time required to change from one grade of product to another. Practical tracer techniques to measure mixing characteristics in high-speed gas flows using {sup 85}Kr have been developed. A study of the measurement method was conducted by calculating the differential values of

  19. Tracer concentration curves and residence time analysis in technological flow systems. 2

    International Nuclear Information System (INIS)

    Pippel, W.

    1976-01-01

    Tracer concentration curves measured in flow systems by means of radioactive isotopes are treated as a two dimensional random process. Comparing them with the family distribution functions described in part I, it follows that only in case of ergodic behaviour of the system tracer curves can be considered as age distribution functions. The conception of ergodicity in residence time systems has been explained with the aid of a time function measurable by a special method of radioactive tracer technique and by the mean value of the residence time obtainable from this function. Furthermore, technological consequences in evaluating tracer concentration curves of real flow systems are discussed with respect to supposed ergodic or nonergodic behaviour. These considerations are of special importance for flow systems with temporary fluctuations in structure. (author)

  20. Transfer function analysis of positron-emitting tracer imaging system (PETIS) data

    International Nuclear Information System (INIS)

    Keutgen, N.; Matsuhashi, S.; Mizuniwa, C.; Ito, T.; Fujimura, T.; Ishioka, N.S.; Watanabe, S.; Sekine, T.; Uchida, H.; Hashimoto, S.

    2002-01-01

    Quantitative analysis of the two-dimensional image data obtained with the positron-emitting tracer imaging system (PETIS) for plant physiology has been carried out using a transfer function analysis method. While a cut leaf base of Chinese chive (Allium tuberosum Rottler) or a cut stem of soybean (Glycine max L.) was immersed in an aqueous solution containing the [ 18 F] F - ion or [ 13 N]NO 3 - ion, tracer images of the leaf of Chinese chive and the trifoliate of soybean were recorded with PETIS. From the time sequence of images, the tracer transfer function was estimated from which the speed of tracer transport and the fraction moved between specified image positions were deduced

  1. 2nd International Conference on Multiscale Computational Methods for Solids and Fluids

    CERN Document Server

    2016-01-01

    This volume contains the best papers presented at the 2nd ECCOMAS International Conference on Multiscale Computations for Solids and Fluids, held June 10-12, 2015. Topics dealt with include multiscale strategy for efficient development of scientific software for large-scale computations, coupled probability-nonlinear-mechanics problems and solution methods, and modern mathematical and computational setting for multi-phase flows and fluid-structure interaction. The papers consist of contributions by six experts who taught short courses prior to the conference, along with several selected articles from other participants dealing with complementary issues, covering both solid mechanics and applied mathematics. .

  2. Long residence times - bad tracer tests?

    Science.gov (United States)

    Ghergut, Julia; Behrens, Horst; Sauter, Martin

    2015-04-01

    Tracer tests conducted at geothermal well doublets or triplets in the Upper Rhine Rift Valley [1] all face, with very few exceptions so far, one common issue: lack of conclusive tracer test results, or tracer signals still undetectable for longer than one or two years after tracer injection. While the reasons for this surely differ from site to site (Riehen, Landau, Insheim, Bruchsal, ...), its effects on how the usefulness of tracer tests is perceived by the non-tracer community are pretty much the same. The 'poor-signal' frustration keeps nourishing two major 'alternative' endeavours : (I) design and execute tracer tests in single-well injection-withdrawal (push-pull), 'instead of' inter-well flow-path tracing configurations; (II) use 'novel' tracer substances instead of the 'old' ones which have 'obviously failed'. Frustration experienced with most inter-well tracer tests in the Upper Rhine Rift Valley has also made them be regarded as 'maybe useful for EGS' ('enhanced', or 'engineered' geothermal systems, whose fluid RTD typically include a major share of values below one year), but 'no longer worthwhile a follow-up sampling' in natural, large-scale hydrothermal reservoirs. We illustrate some of these arguments with the ongoing Bruchsal case [2]. The inter-well tracer test conducted at Bruchsal was (and still is!) aimed at assessing inter-well connectivity, fluid residence times, and characterizing the reservoir structure [3]. Fluid samples taken at the geothermal production well after reaching a fluid turnover of about 700,000 m3 showed tracer concentrations in the range of 10-8 Minj per m3, in the liquid phase of each sample (Minj being the total quantity of tracer injected as a short pulse at the geothermal re-injection well). Tracer signals might actually be higher, owing to tracer amounts co-precipitated and/or adsorbed onto the solid phase whose accumulation in the samples was unavoidable (due to pressure relief and degassing during the very sampling

  3. Methods of international health technology assessment agencies for economic evaluations--a comparative analysis.

    Science.gov (United States)

    Mathes, Tim; Jacobs, Esther; Morfeld, Jana-Carina; Pieper, Dawid

    2013-09-30

    The number of Health Technology Assessment (HTA) agencies increases. One component of HTAs are economic aspects. To incorporate economic aspects commonly economic evaluations are performed. A convergence of recommendations for methods of health economic evaluations between international HTA agencies would facilitate the adaption of results to different settings and avoid unnecessary expense. A first step in this direction is a detailed analysis of existing similarities and differences in recommendations to identify potential for harmonization. The objective is to provide an overview and comparison of the methodological recommendations of international HTA agencies for economic evaluations. The webpages of 127 international HTA agencies were searched for guidelines containing recommendations on methods for the preparation of economic evaluations. Additionally, the HTA agencies were requested information on methods for economic evaluations. Recommendations of the included guidelines were extracted in standardized tables according to 13 methodological aspects. All process steps were performed independently by two reviewers. Finally 25 publications of 14 HTA agencies were included in the analysis. Methods for economic evaluations vary widely. The greatest accordance could be found for the type of analysis and comparator. Cost-utility-analyses or cost-effectiveness-analyses are recommended. The comparator should continuously be usual care. Again the greatest differences were shown in the recommendations on the measurement/sources of effects, discounting and in the analysis of sensitivity. The main difference regarding effects is the focus either on efficacy or effectiveness. Recommended discounting rates range from 1.5%-5% for effects and 3%-5% for costs whereby it is mostly recommended to use the same rate for costs and effects. With respect to the analysis of sensitivity the main difference is that oftentimes the probabilistic or deterministic approach is recommended

  4. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer

    International Nuclear Information System (INIS)

    Bartholomä, Mark D.; He, Huamei; Pacak, Christina A.; Dunning, Patricia; Fahey, Frederic H.; McGowan, Francis X.; Cowan, Douglas B.; Treves, S. Ted; Packard, Alan B.

    2013-01-01

    Introduction: Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an 18 F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on 18 F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of 18 F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake 18 F-labeled rhodamine B by cardiomyocytes. Methods: A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100–150 μCi of 18 F-labeled rhodamine B diethylene glycol ester ([ 18 F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1 mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [ 18 F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Results: Small-animal PET showed intense and uniform uptake of [ 18 F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [ 18 F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ∼ 40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [ 18 F]RhoBDEGF in the mitochondria

  5. Tritium as tracer of flow in constructed wetlands

    International Nuclear Information System (INIS)

    Wachniew, P.; Czuprynski, P.; Maloszewski, P.

    2005-01-01

    Constructed wetlands technology is a cost-effective and environmentally friendly method used world-wide to treat waste waters of different origins. The soluble pollutants are transformed and removed mainly through the processes that occur at surfaces of plants, plant debris or filtering media. The efficiency of soluble pollutants removal is thus primarily related to the extent of contact between waste waters and the reactive surfaces. Residence time distributions function (RTD)is basic characteristic of wetland hydraulic properties and can be obtained by combined use of tracer technique and mathematical modelling. Tritium was used as to obtain RTD's of three parallel cells of a sub-surface flow constructed wetland overgrown with Pharagmites australis in Nowa Slupia. Tritium as a part of water molecule, is an ideal tracer of flow in the highly reactive environment of constructed wetlands. Results of the tracer test interpreted by the assumed model (Multi Flow Dispersion Model) of conservative solute transport revealed a complex structure of flow through the wetland. (author)

  6. Tracer Equivalent Latitude: A Diagnostic Tool for Isentropic Transport Studies.

    Science.gov (United States)

    Allen, Douglas R.; Nakamura, Noboru

    2003-01-01

    Area equivalent latitude based on potential vorticity (PV) is a widely used diagnostic for isentropic transport in the stratosphere and upper troposphere. Here, an alternate method for calculating equivalent latitude is explored, namely, a numerical synthesis of a PV-like tracer from a long-term integration of the advection-diffusion equation on isentropic surfaces. It is found that the tracer equivalent latitude (TrEL) behaves much like the traditional PV equivalent latitude (PVEL) despite the simplified governing physics; this is evidenced by examining the kinematics of the Arctic lower stratospheric vortex. Yet in some cases TrEL performs markedly better as a coordinate for long-lived trace species such as ozone. These instances include analysis of lower stratospheric ozone during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign and three-dimensional reconstruction of total column ozone during November-December 1999 from fitted ozone-equivalent latitude relationship. It is argued that the improvement is due to the tracer being free from the diagnostic errors and certain diabatic processes that affect PV. The sensitivity of TrEL to spatial and temporal resolution, advection scheme, and driving winds is also examined.

  7. Use of Helium-3 and Tritium tracers in oceanography

    International Nuclear Information System (INIS)

    Andrie, Chantal

    1987-01-01

    As tritium considered as a transient tracer has become one of the most promising tool for the study of oceanic circulation and of the ocean capacity to absorb anthropogenic carbon, and as the simultaneous use of its radioactive descendant, Helium-3, brings an additional information (together, these tracers build up a clock in the study of water masses), and as all helium-3 and tritium measurements are made by mass spectroscopy, this research thesis addresses the analytical process, the detection limit, and the method reproducibility associated with this use of both tracers. The author reports and discusses helium-3 data obtained during a measurement campaign which allowed the localisation of an active source and the evidence of an intermediate back current, and tritium data obtained during another measurement campaign which allowed the description of the high time variability of convection processes, and an assessment of water renewal delays and of some deep water circulations. He also reports and discusses the simultaneous use of helium-3 data and tritium data to localize areas where convection processes occur. A theoretical approach to this simultaneous use is proposed which uses a mixing model which distinguishes the venting transit time. Measurement campaigns were performed in Red Sea, western Mediterranean Sea, and north-eastern Atlantic Ocean [fr

  8. Tracer experiment by using radioisotope in surface water environment

    International Nuclear Information System (INIS)

    Suh, K.S.; Kim, K.C.; Chun, I.Y.; Jung, S.H.; Lee, C.W.

    2007-01-01

    Complete text of publication follows. 1. Objective An expansion of industrial activities and urbanization result in still increasing amount of pollutants discharged into surface water. Discharged pollutants in surface water have harmful effects on the ecology of a river system and human beings. Pollutants discharged into surface water is transported and dispersed under conditions characteristic to particular natural water receiver. Radiotracer method is a useful tool for monitoring the pollutant dispersion and description of mixing process taking place in natural streams. A tracer experiment using radioisotope was carried out to investigate the characteristics of a pollutant transport and a determination of the diffusion coefficients in a river system. 2. Methods The upper area of the Keum river was selected for the tracer experiment, which is located in a mid west of Korea. The measurements of the velocity and bathymetry before a tracer experiment were performed to select the sampling lines for a detection of the radioisotope. The radioisotope was instantaneously injected into a flow as a point source by an underwater glass-vial crusher. The detection was made with 60 2inch NaI(Tl) scintillation detectors at 3 transverse lines at a downstream position. The multi-channel data acquisition systems were used to collect and process the signals transmitted from the detectors. Two-dimensional numerical models were used to simulate the hydraulic parameters and the concentration distributions of the radioisotope injected into the river. 3. Results and Conclusion The calculated results such as velocity and concentrations were compared with the measured ones. The dispersion characteristics of the radioisotope were analyzed according to a variation of the flow rate, water level and diffusion coefficients. Also, the diffusion coefficients were calculated by using the measured concentrations and the coefficients obtained from the field experiment were compared with the ones

  9. Tracers of air-sea gas exchange

    International Nuclear Information System (INIS)

    Liss, P.S.

    1988-01-01

    The flux of gas across the air-sea interface is determined by the product of the interfacial concentration difference driving the exchange and a rate constant, often termed the transfer velocity. The concentration-difference term is generally obtained by direct measurement, whereas more indirect approaches are required to estimate the transfer velocity and its variation as a function of controlling parameters such as wind and sea state. Radioactive tracers have proved particularly useful in the estimation of air-sea transfer velocities and, recently, stable purposeful tracers have also started to be used. In this paper the use of the following tracers to determine transfer velocities at the sea surface is discussed: natural and bomb-produced 14 C, dissolved oxygen, 222 Rn and sulphur hexafluoride. Other topics covered include the relation between transfer velocity and wind speed as deduced from tracer and wind-tunnel studies, and the discrepancy between transfer velocities determined by using tracers and from eddy correlation measurements in the atmosphere. (author)

  10. A study on the evaluation of internal leak in valve using acoustic emission method(3)

    International Nuclear Information System (INIS)

    Lee, Sang Guk; Lee, Wook Ryun; Park, Jong Hyuck; Kim, Kwang Hong

    2005-01-01

    The objective of this study is to estimate the feasibility of acoustic emission method for the internal leak from the valves. In this study, valve leak tests using various types of specimen simulated seat damage were performed in order to analyzer acoustic emission properties when leaks arise in valve seat. As a result of leak test for specimens simulated valve seat, we conformed that leak sound level increased in proportion to the increase of hole diameter and leak velocity, and decreased in proportion to the increase of leak depth. And also, leak sound level has hysteresis for leak velocity. From the experimental results, it was suggested that the acoustic emission method for monitoring of leak was feasible.

  11. 11th International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing

    CERN Document Server

    Nuyens, Dirk

    2016-01-01

    This book presents the refereed proceedings of the Eleventh International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing that was held at the University of Leuven (Belgium) in April 2014. These biennial conferences are major events for Monte Carlo and quasi-Monte Carlo researchers. The proceedings include articles based on invited lectures as well as carefully selected contributed papers on all theoretical aspects and applications of Monte Carlo and quasi-Monte Carlo methods. Offering information on the latest developments in these very active areas, this book is an excellent reference resource for theoreticians and practitioners interested in solving high-dimensional computational problems, arising, in particular, in finance, statistics and computer graphics.

  12. International Symposium on Boundary Element Methods : Advances in Solid and Fluid Mechanics

    CERN Document Server

    Tseng, Kadin

    1990-01-01

    The Boundary Element Method (BEM) has become established as an effective tool for the solutions of problems in engineering science. The salient features of the BEM have been well documented in the open literature and therefore will not be elaborated here. The BEM research has progressed rapidly, especially in the past decade and continues to evolve worldwide. This Symposium was organized to provide an international forum for presentation of current research in BEM for linear and nonlinear problems in solid and fluid mechanics and related areas. To this end, papers on the following topics were included: rotary­ wing aerodynamics, unsteady aerodynamics, design and optimization, elasticity, elasto­ dynamics and elastoplasticity, fracture mechanics, acoustics, diffusion and wave motion, thermal analysis, mathematical aspects and boundary/finite element coupled methods. A special session was devoted to parallel/vector supercomputing with emphasis on mas­ sive parallelism. This Symposium was sponsored by United ...

  13. Estimation of the dilution field near a marine outfall by using effluent turbidity as an environmental tracer and comparison with dye tracer data.

    Science.gov (United States)

    Pecly, José Otavio Goulart

    2018-01-01

    The alternative use of effluent turbidity to determine the dilution field of a domestic marine outfall located off the city of Rio de Janeiro was evaluated through field work comprising fluorescent dye tracer injection and tracking with simultaneous monitoring of sea water turbidity. A preliminary laboratory assessment was carried out with a sample of the outfall effluent whose turbidity was measured by the nephelometric method before and during a serial dilution process. During the field campaign, the dye tracer was monitored with field fluorometers and the turbidity was observed with an optical backscattering sensor interfaced to an OEM data acquisition system. About 4,000 samples were gathered, covering an area of 3 km × 3 km near the outfall diffusers. At the far field - where a drift towards the coastline was observed - the effluent plume was adequately labeled by the dye tracer. The turbidity plume was biased due to the high and variable background turbidity of sea water. After processing the turbidity dataset with a baseline detrending method, the plume presented high correlation with the dye tracer plume drawn on the near dilution field. However, dye tracer remains more robust than effluent turbidity.

  14. Design and utilisation of protocols to characterise dynamic PET uptake of two tracers using basis pursuit

    Science.gov (United States)

    Bell, Christopher; Puttick, Simon; Rose, Stephen; Smith, Jye; Thomas, Paul; Dowson, Nicholas

    2017-06-01

    Imaging using more than one biological process using PET could be of great utility, but despite previously proposed approaches to dual-tracer imaging, it is seldom performed. The alternative of performing multiple scans is often infeasible for clinical practice or even in research studies. Dual-tracer PET scanning allows for multiple PET radiotracers to be imaged within the same imaging session. In this paper we describe our approach to utilise the basis pursuit method to aid in the design of dual-tracer PET imaging experiments, and later in separation of the signals. The advantage of this approach is that it does not require a compartment model architecture to be specified or even that both signals are distinguishable in all cases. This means the method for separating dual-tracer signals can be used for many feasible and useful combinations of biology or radiotracer, once an appropriate scanning protocol has been decided upon. Following a demonstration in separating the signals from two consecutively injected radionuclides in a controlled experiment, phantom and list-mode mouse experiments demonstrated the ability to test the feasibility of dual-tracer imaging protocols for multiple injection delays. Increases in variances predicted for kinetic macro-parameters V D and K I in brain and tumoral tissue were obtained when separating the synthetically combined data. These experiments confirmed previous work using other approaches that injections delays of 10-20 min ensured increases in variance were kept minimal for the test tracers used. On this basis, an actual dual-tracer experiment using a 20 min delay was performed using these radio tracers, with the kinetic parameters (V D and K I) extracted for each tracer in agreement with the literature. This study supports previous work that dual-tracer PET imaging can be accomplished provided certain constraints are adhered to. The utilisation of basis pursuit techniques, with its removed need to specify a model

  15. Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume.

    Science.gov (United States)

    Ragagnin, Marilia Nagata; Gorman, Daniel; McCarthy, Ian Donald; Sant'Anna, Bruno Sampaio; de Castro, Cláudio Campi; Turra, Alexander

    2018-01-11

    Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g., computed tomography (CT). This study undertakes the first assessment of the measurement reproducibility of three contrasting approaches across a spectrum of shell architectures and sizes. While our results suggested a certain level of variability inherent for all methods, we conclude that a single measure using sand/water is likely to be sufficient for the majority of studies. However, care must be taken as precision may decline with increasing shell size and structural complexity. CT provided less variation between repeat measures but volume estimates were consistently lower compared to sand/water and will need methodological improvements before it can be used as an alternative. CT indicated volume may be also underestimated using sand/water due to the presence of air spaces visible in filled shells scanned by CT. Lastly, we encourage authors to clearly describe how volume estimates were obtained.

  16. Rapid dual-tracer PTSM+ATSM PET imaging of tumour blood flow and hypoxia: a simulation study

    International Nuclear Information System (INIS)

    Rust, T C; Kadrmas, D J

    2006-01-01

    Blood flow and hypoxia are interrelated aspects of physiology that affect cancer treatment and response. Cu-PTSM and Cu-ATSM are related PET tracers for blood flow and hypoxia, and the ability to rapidly image both tracers in a single scan would bring several advantages over conventional single-tracer techniques. Using dynamic imaging with staggered injections, overlapping signals for multiple PET tracers may be recovered utilizing information from kinetics and radioactive decay. In this work, rapid dual-tracer PTSM+ATSM PET was simulated and tested as a function of injection delay, order and relative dose for several copper isotopes, and the results were compared relative to separate single-tracer data. Time-activity curves representing a broad range of tumour blood flow and hypoxia levels were simulated, and parallel dual-tracer compartment modelling was used to recover the signals for each tracer. The main results were tested further using a torso phantom simulation of PET tumour imaging. Using scans as short as 30 minutes, the dual-tracer method provided measures of blood flow and hypoxia similar to single-tracer imaging. The best performance was obtained by injecting PTSM first and using a somewhat higher dose for ATSM. Comparable results for different copper isotopes suggest that tracer kinetics with staggered injections play a more important role than radioactive decay in the signal separation process. Rapid PTSM+ATSM PET has excellent potential for characterizing both tumour blood flow and hypoxia in a single, fast scan, provided that technological hurdles related to algorithm development and routine use can be overcome

  17. Advancing internal erosion monitoring using seismic methods in field and laboratory studies

    Science.gov (United States)

    Parekh, Minal L.

    This dissertation presents research involving laboratory and field investigation of passive and active methods for monitoring and assessing earthen embankment infrastructure such as dams and levees. Internal erosion occurs as soil particles in an earthen structure migrate to an exit point under seepage forces. This process is a primary failure mode for dams and levees. Current dam and levee monitoring practices are not able to identify early stages of internal erosion, and often the result is loss of structure utility and costly repairs. This research contributes to innovations for detection and monitoring by studying internal erosion and monitoring through field experiments, laboratory experiments, and social and political framing. The field research in this dissertation included two studies (2009 and 2012) of a full-scale earthen embankment at the IJkdijk in the Netherlands. In both of these tests, internal erosion occurred as evidenced by seepage followed by sand traces and boils, and in 2009, eventual failure. With the benefit of arrays of closely spaced piezometers, pore pressure trends indicated internal erosion near the initiation time. Temporally and spatially dense pore water pressure measurements detected two pore water pressure transitions characteristic to the development of internal erosion, even in piezometers located away from the backward erosion activity. At the first transition, the backward erosion caused anomalous pressure decrease in piezometers, even under constant or increasing upstream water level. At the second transition, measurements stabilized as backward erosion extended further upstream of the piezometers, as shown in the 2009 test. The transitions provide an indication of the temporal development and the spatial extent of backward erosion. The 2012 IJkdijk test also included passive acoustic emissions (AE) monitoring. This study analyzed AE activity over the course of the 7-day test using a grid of geophones installed on the

  18. New methods to quantify the cracking performance of cementitious systems made with internal curing

    Science.gov (United States)

    Schlitter, John L.

    The use of high performance concretes that utilize low water-cement ratios have been promoted for use in infrastructure based on their potential to increase durability and service life because they are stronger and less porous. Unfortunately, these benefits are not always realized due to the susceptibility of high performance concrete to undergo early age cracking caused by shrinkage. This problem is widespread and effects federal, state, and local budgets that must maintain or replace deterioration caused by cracking. As a result, methods to reduce or eliminate early age shrinkage cracking have been investigated. Internal curing is one such method in which a prewetted lightweight sand is incorporated into the concrete mixture to provide internal water as the concrete cures. This action can significantly reduce or eliminate shrinkage and in some cases causes a beneficial early age expansion. Standard laboratory tests have been developed to quantify the shrinkage cracking potential of concrete. Unfortunately, many of these tests may not be appropriate for use with internally cured mixtures and only provide limited amounts of information. Most standard tests are not designed to capture the expansive behavior of internally cured mixtures. This thesis describes the design and implementation of two new testing devices that overcome the limitations of current standards. The first device discussed in this thesis is called the dual ring. The dual ring is a testing device that quantifies the early age restrained shrinkage performance of cementitious mixtures. The design of the dual ring is based on the current ASTM C 1581-04 standard test which utilizes one steel ring to restrain a cementitious specimen. The dual ring overcomes two important limitations of the standard test. First, the standard single ring test cannot restrain the expansion that takes place at early ages which is not representative of field conditions. The dual ring incorporates a second restraining ring

  19. Coefficients of tracer transfer through membranes. Pt. 7

    Energy Technology Data Exchange (ETDEWEB)

    Dorabialska, A; Hawlicka, E; Plonka, A [Politechnika Lodzka (Poland)

    1974-01-01

    The doubled value of the tracer transfer coefficient in the self-diffusion process is equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The fundamental phenomenological relation can be deduced for the coefficients of tracer transfer between two phases of electrolyte solutions spearated by a virtual boundary. Indeed, the doubled value of the tracer mobility in the self-diffusion experiment (no concentration gradient of the traced substance) is equal to the sum of the tracer mobilities in the diffusion (tracer movement along with the concentration gradient of the traced substance) and interfusion experiments (tracer movement against the concentration gradient of the traced substance). Thus the doubled value of the tracer transfer coefficient in the self-diffusion process should be equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The experimental verification of that fundamental relation is presented.

  20. Preparation of radioactive tracer for studying sediment movement

    International Nuclear Information System (INIS)

    Hussain, S.D.; Ghauri, G.A.; Qureshi, M.H.; Khan, N.A.

    1983-06-01

    In order to study the movement of sediment in harbours, estuaries and streams, artificial sediment in the form of glass is prepared. A preselected nuclide is added to the glass during its manufacture. The density and size distribution of the glass particles is method with that of the natural sediment. The activation of the artificial sediment in a reactor changes the nuclide into a radioactive isotope thereby tagging it and making it possible to trace its movement with suitable radiation detector. The method of tracer preparation is described with special reference to sadiment movement studies at Karachi harbour. (authors)

  1. A study on the determination of diffusion coefficient of carbon in 304 austenitic stainless steels by internal friction method

    International Nuclear Information System (INIS)

    Kim, K.S.; Kim, T.H.

    1982-01-01

    Internal friction peaks associated with the presence of carbon in 18-8 type 304 stainless steel have been observed from measurements with a torsion pendulum. The temperature for maximum internal friction lies between 250degC and 300degC with a frequency of vibration. The height of the peak rises and the position of the peak shifts to a lower temperature with an increase of the carbon content. And a comparison of the activation energy and the diffusion coefficient determined by internal friction methods with those measured in conventional macro-diffusion experiments reveals that the diffusion data measured by internal friction method and the diffusion data measured by conventional method exist in the same line. It follows from the above fact that observed internal friction peak is associated with the stress-induced diffusion of carbon in face-centered cubic alloys. (Author)

  2. Biological tracer for waste site characterization

    International Nuclear Information System (INIS)

    Strong-Gunderson, J.

    1995-01-01

    Remediating hazardous waste sites requires detailed site characterization. In groundwater remediation, characterizing the flow paths and velocity is a major objective. Various tracers have been used for measuring groundwater velocity and transport of contaminants, colloidal particles, and bacteria and nutrients. The conventional techniques use dissolved solutes, dyes. and gases to estimate subsurface transport pathways. These tracers can provide information on transport and diffusion into the matrix, but their estimates for groundwater flow through fractured regions are very conservative. Also, they do not have the same transport characteristics as bacteria and suspended colloid tracers, both of which must be characterized for effective in-place remediation. Bioremediation requires understanding bacterial transport and nutrient distribution throughout the acquifer, knowledge of contaminants s mobile colloidal particles is just essential

  3. Impact of Air Entraining Method on the Resistance of Concrete to Internal Cracking

    Science.gov (United States)

    Wawrzeńczyk, Jerzy; Molendowska, Agnieszka

    2017-10-01

    This paper presents the test results of air entrained concrete mixtures made at a constant W/C ratio of 0.44. Three different air entraining agents were used: polymer microspheres, glass microspheres and a conventional air entraining admixture. The aim of this study was to compare the effectiveness of the air entraining methods. Concrete mixture tests were performed for consistency (slump test), density and, in the case of AEA series, air content by pressure method. Hardened concrete tests were performed for compressive strength, water absorption, resistance to chloride ingress, and freeze-thaw durability - resistance to internal cracking tests were conducted in accordance with PN-88/B-06250 on cube specimens and with the modified ASTM C666 A test method on beam specimens; porosity characteristics (A, A300, \\bar L) were determined to PN-EN 480-11:1998. No significant mass and length changes were recorded for the concrete air entrained with the conventional methods or with polymer microspheres. The results indicate that polymer microspheres are a very good alternative to traditional air entraining methods for concrete, providing effective air entrainment and protection from freezing and thawing. The glass microsphere-based concretes showed insufficient freeze-thaw resistance. The test results indicate that both the conventional methods (AEA) and the air entrainment by polymer microspheres are effective air entraining methods. It has to be noted that in the case of the use of polymer microspheres, a comparable value of \\bar L and a very good freeze-thaw resistance can be achieved at a noticeably lower air and micropore contents and at lower strength loss.

  4. Tracer applications in oil reservoirs in Brazil

    International Nuclear Information System (INIS)

    Moreira, R.M.; Ferreira Pinto, A.M.

    2004-01-01

    Radiotracer applications in oil reservoirs in Brazil started in 1997 at the request of the State Oil Company (Petrobras) at the Carmoplois oilfield. 1 Ci of HTO was injected in a regular five-spot plot and the results obtained were quite satisfactory. Shortly after this test one other request asked for distinguishing the contribution of different injection wells to a production well. It was then realized that other tracers should be available. As a first choice 35 SCN - has been selected since it could be produced at CDTN. An alternative synthesis path was defined which shortened post-irradiation manipulations. The tracer was tested in core samples and a field injection, simultaneously with HTO, was carried out at the Buracica field; again the HTO performed well but 35 SCN - showed up well ahead. Presently the HTO applications are being done on a routine basis. All in all, four tests were performed (some are still ongoing), and the detection limits for both 3 H and 35 S were optimized by refining the sample preparation stage. Lanthanide complexes used as activable tracers are also an appealing option, however core tests performed so far with La-, Ce- and Eu-EDTA indicated some delay of the tracer, so other complexants such as DOTA are to be tried in further laboratory tests and in a field application. Thus, a deeper understanding of their complexation chemistry and carefully conducted tests must be performed before lanthanide complexes can be qualified as reliable oil reservoir tracers. More recently, Petrobras has been asking for partitioning tracers intended for SOR measurement

  5. Specific absorbed fractions of energy at various ages from internal photon sources: 1, Methods

    International Nuclear Information System (INIS)

    Cristy, M.; Eckerman, K.F.

    1987-04-01

    Specific absorbed fractions (PHI's) in various organs of the body (target organs) from sources of monoenergetic photons in various other organs (source organs) are tabulated. This volume outlines various methods used to compute the PHI-values and describes how the ''best'' estimates recommended by us are chosen. These PHI-values can be used in calculating the photon component of the dose-equivalent rate in a given target organ from a given radionuclide that is present in a given source organ. The International Commission on Radiological Protection recognizes that the endosteal, or bone surface, cells are the tissue at risk for bone cancer. We have applied the dosimetry methods that Spiers and co-workers developed for beta-emitting radionuclides deposited in bone to follow the transport of secondary electrons that were freed by photon interactions through the microscopic structure of the skeleton. With these methods we can estimate PHI in the endosteal cells and can better estimate PHI in the active marrow; the latter is overestimated with the methods at photon energies below 200 keV. 41 refs., 25 figs., 23 tabs

  6. The Influence of Fees on Supervision of Licensed Professional Counselor Interns in Texas: A Mixed-Methods Study

    Science.gov (United States)

    Stark, Marcella Dortch

    2010-01-01

    Purpose. The purpose of this study was to explore the influence of payment status on perceptions of Licensed Professional Counselor (LPC) Interns regarding aspects of the supervisory relationship. Method. Survey responses from 230 LPC Interns in Texas were collected using SurveyMonkey[TM] (2009) to examine how supervision fees influence: (a)…

  7. Continuing to Confront COPD International Patient Survey : methods, COPD prevalence, and disease burden in 2012-2013

    NARCIS (Netherlands)

    Landis, Sarah H.; Muellerova, Hana; Mannino, David M.; Menezes, Ana M.; Han, MeiLan K.; van der Molen, Thys; Ichinose, Masakazu; Aisanov, Zaurbek; Oh, Yeon-Mok; Davis, Kourtney J.

    2014-01-01

    Purpose: The Continuing to Confront COPD International Patient Survey aimed to estimate the prevalence and burden of COPD globally and to update findings from the Confronting COPD International Survey conducted in 1999-2000. Materials and methods: Chronic obstructive pulmonary disease (COPD)

  8. IR thermography methods for evaluation of internal defects in light composite armours

    International Nuclear Information System (INIS)

    Swiderski, W.; Szabra, D.; Szudrowicz, M.

    2009-01-01

    Complete text of publication follows. Light composite armour is a preferred solution against military and paramilitary sources of present threats as the reducing mass of battle vehicles provides a possibility of their quick air-transport. The light armours of these vehicles should be resistant against: common and rifle bullets, grenades, anti-personal mines, IED - improvised explosive devices. The range of military applications anticipated for composite armours covers a broad spectrum of materials and designs. Materials of composite armours include graphite epoxy, glass epoxy and aramid fiber composites. The composites that have been examined can include a variety of defects, such as ballistic impacts, embedded defects, manufacturing defects, thermal damage, moisture ingress and other induced defects. Methods for testing ballistic protection of light armours are known and used. First of all they consist of checking armours resistance against the bullets where the bullet velocity is known. Moreover the V50 velocity is defined during the test. In this method the V 50 velocity of a round or standard fragment is defined (according to STANAG 2920) as the velocity at which armour is penetrated at the probability 50%. The distribution of points hit by bullets or fragments on the surface of an armour is also important. In fact, only correct distribution of these points provides a guaranty for an impartial assessment of tested designs. After hitting by a bullet, shape and size of an area of damage in composite armours depends on the type and design of armour, and type of reinforcing material is particularly important. Knowledge of damage characteristics allows to arrange hitting points to avoid overlapping of damaged areas. Nondestructive testing by using IR thermography methods is very useful in evaluation of internal defects. In the paper we present the dependence between the energy of fragments/or bullets and the dimension of internal defects. (author)

  9. A study plan for determining recharge rates at the Hanford Site using environmental tracers

    International Nuclear Information System (INIS)

    Murphy, E.M.; Szercsody, J.E.; Phillips, S.J.

    1991-02-01

    This report presents a study plan for estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, 36 Cl, 3 H, and 2 H/ 18 O. Atmospheric levels of 36 Cl and 3 H increased during nuclear bomb testing in the Pacific, and the resulting ''bomb pulse'' or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resulted in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, 129 I, and 99 Tc. Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Six tracer techniques (total chloride, 36 Cl, 3 H, nitrate, 129 I, and 99 Tc) will be tested on at least one site in the Quincy sand, one site in the Warden silt loam, and the background site, to determine which combination of tracers works best for a given soil type. In subsequent years, additional sites will be investigated. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial variability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other arid sites. 166 refs., 41 figs., 16 tabs

  10. Geologic flow characterization using tracer techniques

    International Nuclear Information System (INIS)

    Klett, R.D.; Tyner, C.E.; Hertel, E.S. Jr.

    1981-04-01

    A new tracer flow-test system has been developed for in situ characterization of geologic formations. This report describes two sets of test equipment: one portable and one for testing in deep formations. Equations are derived for in situ detector calibration, raw data reduction, and flow logging. Data analysis techniques are presented for computing porosity and permeability in unconfined isotropic media, and porosity, permeability and fracture characteristics in media with confined or unconfined two-dimensional flow. The effects of tracer pulse spreading due to divergence, dispersion, and porous formations are also included

  11. SIMULASI JARINGAN KOMPUTER MENGGUNAKAN CISCO PACKET TRACER

    Directory of Open Access Journals (Sweden)

    M Mufadhol

    2012-01-01

    Full Text Available Perkembangan jaringan komputer saat ini begitu pesat, monitoring jaringan komputer akan menjadi suatu hal yang sulit dan rumit. Koneksi jaringan komputer merupakan suatu hal yang mendasar dalam suatu jaringan, karena bila koneksi itu bermasalah maka semua jenis aplikasi yang dijalankan melalui jaringan komputer tidak dapat digunakan. Cisco packet tracer dapat digunakan untuk simulasi yang mencerminkan arsitektur dan juga model dari jaringan komputer pada sistem jaringan yang digunakan. Dengan menggunakan aplikasi cisco packet tracer, simulasi mengenai jaringan dapat dimanfaatkan menjadi informasi tentang keadaan koneksi komputer dalam suatu jaringan.

  12. Development of a downhole tool measuring real-time concentration of ionic tracers and pH in geothermal reservoirs

    Science.gov (United States)

    Hess, Ryan F.; Boyle, Timothy J.; Limmer, Steven; Yelton, William G.; Bingham, Samuel; Stillman, Greg; Lindblom, Scott; Cieslewski, Grzegorz

    2014-06-01

    For enhanced or Engineered Geothermal Systems (EGS) geothermal brine is pumped to the surface via the production wells, the heat extracted to turn a turbine to generate electricity, and the spent brine re-injected via injection wells back underground. If designed properly, the subsurface rock formations will lead this water back to the extraction well as heated brine. Proper monitoring of these geothermal reservoirs is essential for developing and maintaining the necessary level of productivity of the field. Chemical tracers are commonly used to characterize the fracture network and determine the connectivity between the injection and production wells. Currently, most tracer experiments involve injecting the tracer at the injection well, manually collecting liquid samples at the wellhead of the production well, and sending the samples off for laboratory analysis. While this method provides accurate tracer concentration data at very low levels of detection, it does not provide information regarding the location of the fractures which were conducting the tracer between wellbores. Sandia is developing a high-temperature electrochemical sensor capable of measuring tracer concentrations and pH downhole on a wireline tool. The goal of this effort is to collect real-time pH and ionic tracer concentration data at temperatures up to 225 °C and pressures up to 3000 psi. In this paper, a prototype electrochemical sensor and the initial data obtained will be presented detailing the measurement of iodide tracer concentrations at high temperature and pressure in a newly developed laboratory scale autoclave.

  13. Fairness reactions to personnel selection methods: An international comparison between the Netherlands, the United States, France, Spain, Portugal, and Singapore

    NARCIS (Netherlands)

    Anderson, N.; Witvliet, C.

    2008-01-01

    This paper reports reactions to employee selection methods in the Netherlands and compares these findings internationally against six other previously published samples covering the United States, France, Spain, Portugal, and Singapore. A sample of 167 participants rated 10 popular assessment

  14. Internal consistency and validity of an observational method for assessing disability in mobility in patients with osteoarthritis.

    NARCIS (Netherlands)

    Steultjens, M.P.M.; Dekker, J.; Baar, M.E. van; Oostendorp, R.A.B.; Bijlsma, J.W.J.

    1999-01-01

    Objective: To establish the internal consistency of validity of an observational method for assessing diasbility in mobility in patients with osteoarthritis (OA), Methods: Data were obtained from 198 patients with OA of the hip or knee. Results of the observational method were compared with results

  15. Marginal and internal fit of zirconia copings obtained using different digital scanning methods

    Directory of Open Access Journals (Sweden)

    Lorena Oliveira PEDROCHE

    Full Text Available Abstract The objective of this study was to evaluate the marginal and internal fit of zirconia copings obtained with different digital scanning methods. A human mandibular first molar was set in a typodont with its adjacent and antagonist teeth and prepared for an all-ceramic crown. Digital impressions were made using an intraoral scanner (3Shape. Polyvinyl siloxane impressions and Type IV gypsum models were also obtained and scanned with a benchtop laboratory scanner (3Shape D700. Ten zirconia copings were fabricated for each group using CAD-CAM technology. The marginal and internal fit of the zirconia copings was assessed by the silicone replica technique. Four sections of each replica were obtained, and each section was evaluated at four points: marginal gap (MG, axial wall (AW, axio-occlusal edge (AO and centro-occlusal wall (CO, using an image analyzing software. The data were submitted to one-way ANOVA and Tukey’s test (α = 0.05. They showed statistically significant differences for MG, AO and CO. Regarding MG, intraoral scanning showed lower gap values, whereas gypsum model scanning showed higher gap values. Regarding AO and CO, intraoral digital scanning showed lower gap values. Polyvinyl siloxane impression scanning and gypsum model scanning showed higher gap values and were statistically similar. It can be concluded that intraoral digital scanning provided a lower mean gap value, in comparison with conventional impressions and gypsum casts scanned with a standard benchtop laboratory scanner.

  16. BE-2004: International meeting on updates in best estimate methods in nuclear installation safety analysis. Proceedings

    International Nuclear Information System (INIS)

    2004-01-01

    BE-2004 is the second in a series of embedded conferences that focus on generating and sustaining the dialogue regarding the use of best estimate plus uncertainty tools to license operational and advanced nuclear systems. The first conference in the series was held during the 2000 American Nuclear Society Winter Meeting in Washington. BE-2004 is international in scope, as evidenced by the multinational sources of the papers, and is intended to serve as an opportunity for information exchange between research scientists, practicing engineers, and regulators. However, as appropriate to a follow-on conference, the primary theme of BE-2004 is to provide updates reflecting the progress in best estimate methodologies in the last four years. Examples include research activities that evolved from the current Generation-IV initiative and other new designs [Nuclear Energy Research Initiative (NERI), etc.], core design and neutronic calculations that support best estimate analysis, use of advanced methodologies to produce plant licensing procedures competitive with best estimate methods, and of course current philosophical and technical issues that need to be considered in implementing best estimate codes as an established part of the international licensing framework

  17. FOREWORD: 5th International Workshop on New Computational Methods for Inverse Problems

    Science.gov (United States)

    Vourc'h, Eric; Rodet, Thomas

    2015-11-01

    This volume of Journal of Physics: Conference Series is dedicated to the scientific research presented during the 5th International Workshop on New Computational Methods for Inverse Problems, NCMIP 2015 (http://complement.farman.ens-cachan.fr/NCMIP_2015.html). This workshop took place at Ecole Normale Supérieure de Cachan, on May 29, 2015. The prior editions of NCMIP also took place in Cachan, France, firstly within the scope of ValueTools Conference, in May 2011, and secondly at the initiative of Institut Farman, in May 2012, May 2013 and May 2014. The New Computational Methods for Inverse Problems (NCMIP) workshop focused on recent advances in the resolution of inverse problems. Indeed, inverse problems appear in numerous scientific areas such as geophysics, biological and medical imaging, material and structure characterization, electrical, mechanical and civil engineering, and finances. The resolution of inverse problems consists of estimating the parameters of the observed system or structure from data collected by an instrumental sensing or imaging device. Its success firstly requires the collection of relevant observation data. It also requires accurate models describing the physical interactions between the instrumental device and the observed system, as well as the intrinsic properties of the solution itself. Finally, it requires the design of robust, accurate and efficient inversion algorithms. Advanced sensor arrays and imaging devices provide high rate and high volume data; in this context, the efficient resolution of the inverse problem requires the joint development of new models and inversion methods, taking computational and implementation aspects into account. During this one-day workshop, researchers had the opportunity to bring to light and share new techniques and results in the field of inverse problems. The topics of the workshop were: algorithms and computational aspects of inversion, Bayesian estimation, Kernel methods, learning methods

  18. FOREWORD: 4th International Workshop on New Computational Methods for Inverse Problems (NCMIP2014)

    Science.gov (United States)

    2014-10-01

    This volume of Journal of Physics: Conference Series is dedicated to the scientific contributions presented during the 4th International Workshop on New Computational Methods for Inverse Problems, NCMIP 2014 (http://www.farman.ens-cachan.fr/NCMIP_2014.html). This workshop took place at Ecole Normale Supérieure de Cachan, on May 23, 2014. The prior editions of NCMIP also took place in Cachan, France, firstly within the scope of ValueTools Conference, in May 2011 (http://www.ncmip.org/2011/), and secondly at the initiative of Institut Farman, in May 2012 and May 2013, (http://www.farman.ens-cachan.fr/NCMIP_2012.html), (http://www.farman.ens-cachan.fr/NCMIP_2013.html). The New Computational Methods for Inverse Problems (NCMIP) Workshop focused on recent advances in the resolution of inverse problems. Indeed, inverse problems appear in numerous scientific areas such as geophysics, biological and medical imaging, material and structure characterization, electrical, mechanical and civil engineering, and finances. The resolution of inverse problems consists of estimating the parameters of the observed system or structure from data collected by an instrumental sensing or imaging device. Its success firstly requires the collection of relevant observation data. It also requires accurate models describing the physical interactions between the instrumental device and the observed system, as well as the intrinsic properties of the solution itself. Finally, it requires the design of robust, accurate and efficient inversion algorithms. Advanced sensor arrays and imaging devices provide high rate and high volume data; in this context, the efficient resolution of the inverse problem requires the joint development of new models and inversion methods, taking computational and implementation aspects into account. During this one-day workshop, researchers had the opportunity to bring to light and share new techniques and results in the field of inverse problems. The topics of the

  19. The fairness, predictive validity and acceptability of multiple mini interview in an internationally diverse student population- a mixed methods study

    OpenAIRE

    Kelly, Maureen E.; Dowell, Jon; Husbands, Adrian; Newell, John; O'Flynn, Siun; Kropmans, Thomas; Dunne, Fidelma P.; Murphy, Andrew W.

    2014-01-01

    Background International medical students, those attending medical school outside of their country of citizenship, account for a growing proportion of medical undergraduates worldwide. This study aimed to establish the fairness, predictive validity and acceptability of Multiple Mini Interview (MMI) in an internationally diverse student population. Methods This was an explanatory sequential, mixed methods study. All students in First Year Medicine, National University of Ireland Galway 2012 we...

  20. The use of foresight methods in strategic raw materials intelligence - an international review

    Science.gov (United States)

    Konrat Martins, Marco Antonio; Bodo, Balazs; Falck, Eberhard

    2017-04-01

    Foresight methods are systematic attempts to look into the longer term future of science, society, economy and technology. There is a range of tools and techniques that can be used individually or combined, most commonly classified into qualitative, quantitative or semi-quantitative methods, that follow an exploratory or normative approach. These tools can help to identify the longer term visions, orienting policy formulation and decisions, triggering actions, among other objectives. There is an identified lack of European strategic foresight knowledge in the raw materials domain. Since the European Raw Materials Initiative was launched in 2008, the EU has been attempting to overcome challenges related to the future access of non-energy and non-agricultural raw materials. In this context, the ongoing H2020 project, MICA (Mineral Intelligence Capacity Analysis, Grant Agreement No. 689648), has been launched to answer to stakeholders needs by consolidating relevant data, determining relevant methods and tools, and investigating Raw Materials Intelligence options for European mineral policy development, all tailored to fit under the umbrella of a European Raw Materials Intelligence Capacity Platform (EU-RMICP). As part of the MICA activities, an assessment of best practices and benchmarks of international raw materials foresight case studies has been carried out in order to review how EU and non-EU countries have employed foresight. A pool of 30 case studies has been collected and reviewed internationally, one third of which were selected for detailed assessment. These were classified according to their background and goals, in function of methods employed, and to the purpose of each method in the study: a total of 12 different methods were identified in these studies. For longer time frames, qualitative predictive methods such as Scenario Development have been repeatedly observed for mineral raw materials foresight studies. Substantial variations were observed in