A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

Energy Technology Data Exchange (ETDEWEB)

Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

2009-07-01

The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

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

Studies on the distribution of radioactivity in the organism and rate of incorporation of radioactivity into the tissue proteins of monogastric animals after intravenous injection of tracer amino acids

International Nuclear Information System (INIS)

Simon, O.; Muenchmeyer, R.; Bergner, H.; Zebrowska, T.

1976-01-01

Radioactive amino acids ( 14 C leucine and 3 H lysine) were administrated to pigs by means of a catheter tube into the jugular vein. Subsequently, the time pattern of the distribution of the specific amino acid radioactivity was followed in the TCE soluble and TCE precipitable fractions of the blood plasma (TCE = trichloroacetic acid). Rats were injected 14 C into the portal vein. The animals were killed after incorporation periods of 2 to 60 minutes, and the levels of specific radioactivity were estimated in the TCE soluble and TCE precipitable fractions of the blood plasma, in the liver and in the skeletal muscles. The experimental results indicated that the specific radioactivity of the tracer amino acids and the rate of incorporation of radioactivity into tissue proteins were influenced by the size of the free amino acid pool within the range of distribution of the tracer. An estimation of the magnitude of the pool of free amino acids within the distribution range of the tracer can be obtained from the curve pattern for the decline of specific radioactivity of the corresponding free amino acid in the blood plasma. This pool exhibits a high rate of turnover. In all studies made to evaluate in vivo processes of protein synthesis using radioactive tracer amino acids it will be particularly important that consideration is given to the specific radioactivity of the amino acid in the precursor pool for protein synthesis. (author)

Study of solid and liquid behavior in large copper flotation cells (130 m2) using radioactive tracers

International Nuclear Information System (INIS)

Diaz, F.; Jimenez, O.; Yianatos, J.; Contreras, F.

2013-01-01

The behavior of the solid and liquid phases, in large flotation cells, was characterized by means of the radioactive tracer technique. The use of radioactive tracers enabled the identification of the Residence Time Distribution, of floatable and non-floatable solid, from continuous (on-line) measuring at the output streams of the flotation cells. For this study, the proper radioactive tracers were selected and applied in order to characterize the different phases; i.e. for liquid phase Br-82 as Ammonium Bromide, for floatable solid recovered in the concentrate Cu-64, and for non-floatable solid in three particle size classes (coarse: >150 μm, intermediate: 45 μm, and fine: <45 μm), Na-24. The experimental results confirmed the strong effect of particle size on the Residence Time Distribution, and mean residence time of solids in larger flotation cells, and consequently in flotation hydrodynamics. From a hydrodynamic point of view, the experimental data confirmed that a single mechanical flotation cells, of large size, can deviate significantly from perfect mixing. The experimental work was developed in a 130 m3 industrial flotation cell of the rougher circuit at El Teniente Division, Codelco-Chile. (authors)

Instantaneous axial velocity of a radioactive tracer determined with radioactive particle tracking

Energy Technology Data Exchange (ETDEWEB)

Fraguio, Maria Sol; Cassanello, Miryan C., E-mail: miryan@di.fcen.uba.a [Universidad de Buenos Aires (Argentina). Facultad de Ciencias Exactas y Naturales. Programa de Investigacion y Desarrollo de Fuentes Alternativas de Materias Primas y Energia (PINMATE); Cardona, Maria Angelica; Hojman, Daniel, E-mail: cardona@tandar.cnea.gov.a [CONICET, Buenos Aires (Argentina); Somacal, Hector [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina). Centro Atomico Constituyentes. Dept. de Fisica

2009-07-01

Radioactive Particle Tracking (RPT) is a technique that has been successfully used to get features of the liquid and/or the solid motion in multiphase contactors. It is one of the rare techniques able to provide experimental data in dense and strongly turbulent multiphase media. Validation of the technique has always been based on comparing the estimated mean velocity to an imposed mean velocity although the extracted features are frequently related to the instantaneous velocities. The present work pursues the analysis, through calibration experiments, of the ability of RPT to get the actual tracer instantaneous velocities. With this purpose, the motion of a radioactive tracer attached to a moving rod driven by a pneumatic system is reconstructed from the combined response of an array of 10 NaI(Tl) scintillation detectors. Simultaneously, the tracer motion is registered through an encoder able to establish the axial tracer coordinate with high precision and high time resolution. The tracer is a gold particle, activated by neutron bombardment. The rod is moved at different velocities and it travels upwards and downwards close to the column centre. A mini-pilot scale bubble column is used as the test facility. The model liquid is tap water in batch mode and the gas is air, flowing at different gas velocities, spanning the homogeneous and the heterogeneous flow regimes. Time series of the entirety response of all the detectors, while the rod is moving at different imposed velocities within the two phase emulsion, are measured with a sampling period of 0.03 s during about 2 minutes. The instantaneous tracer positions and velocities reconstructed from RPT and the one obtained from the encoder response are compared under different operating conditions and for different tracer velocities. (author)

The use of radioactive and other tracers in oil and gas measurement

International Nuclear Information System (INIS)

Edmonds, E.A.

1985-01-01

A description and critical discussion of the use of tracer techniques of flowrate measurement in the oil and gas industries. Radioactive tracers are discussed in particular, with emphasis on the practical aspects of their use. Radiotracers suitable for use in industrial environments are described and discussed. The advantages of radiotracers over conventional chemical tracers are reviewed and the logistical problems associated with the use of radioactive materials are considered. The results of measurements conducted using radiotracers on operating plant and on calibration facilities are presented with a discussion of the accuracy of measurement of flowrate which is achievable: potentially, in ideal circumstances, and in practical situations. The modification of tracer techniques of flow measurement to enable residence time distributions to be evaluated and leaks to be located and quantified on operating process plant is illustrated and discussed. The use of specially synthesized radiochemicals for tracing complex petrochemical processes involving chemical reactions and multiproduct streams is described. The use of novel non-radioactive tracers and specialized detection systems is also described, again with practical illustrations of experience in the field. The benefits offered by the use of these tracers and the limitations encountered are discussed. (author)

Study of the mineralization of coral implanted in vivo by radioactive tracers

International Nuclear Information System (INIS)

Irigaray, J.L.; Sauvage, T.; Oudadesse, H.; El Fadl, H.

1993-01-01

Coral may be used as a substitution biomaterial to the bone graft, due to its physico-chemical and architectural properties. The coral, after its implantation 'in vivo' reaches a mineral composition and crystalline structure comparable to those of a bone. The calcification mechanism of this implant is studied using 45 Ca as radioactive tracer. The atomic elements contained in the initial coral were analysed in function of the time spent in the body, by marking the calcium and the strontium contained in its structure. (K.A.) 8 refs.; 6 figs.; 4 tabs

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)

The medical applications of radioactive tracers

Energy Technology Data Exchange (ETDEWEB)

Hamilton, J.G.

1947-12-31

This report provides a broad yet in depth overview of the use of radioactive materials as tracers in medicine and biology for the period of 1935--1947. Particular attention is paid to is of radio-sodium, radio-iodine, radio-iron, radio-phosphorus, radio-strontium, and fission products. The main thrust of this paper is human rather than animal work and focuses in work that has been published.

Determination of the dispersion coefficient, in rivers through radioactive and fluorescent tracers

International Nuclear Information System (INIS)

Almeida Rosso, T.C. de.

1986-03-01

The purpose of this work was to determine experimentally the dispersion coefficient in natural streams through the aplication of radioactive and fluorescent tracers. The technique used to obtain the experimental data was the simmultaneous injection of the radioactive tracer Bromim - 82 and the fluorescent ones, Amidorodamine G. extra and Uranine. A comparison among these different tracers is shown as well as the performance of Uranine in a poluented stream in the presence of suspended sediments. The site chosen for the experiments was the Piabanha River, between Pedro do Rio and Areal, located at Rio de Janeiro state, in a nearly 20 Km strech. (Author) [pt

Bottom sediment transport study at Haiphong port using radioactive scandium as tracer

International Nuclear Information System (INIS)

Pham Ngoc Chuong; Phan Son Hai; Pham Duy Hien

1993-01-01

A radioisotope tracer experiment was performed for investigating the bedload movement at the site near the access channel to Haiphong port, North Vietnam. The scandium glass and a number of mechanical devices were manufactured locally for the experiment. Simple and safe procedures were adopted for the production, transportation and injection of radioactive tracer materials. Five tracking experiments were carried out covering the period of 84 days in winter 1992-1993. The experimental results provide a firm basis for elaborating appropriate measures against the siltation problem at Haiphong port, especially for the design of a new access channel with a better orientation with respect to the directions of the water flow and bedload transport, as proposed recently by the Port Authority. (Author). 2 refs, 4 figs

Use of radioactive and neutron-activatable tracers to determine effective hydrogeologic parameters

International Nuclear Information System (INIS)

Yu, C.; Jester, W.A.; Jarrett, A.R.

1985-01-01

The migration of nuclides in a geologic medium is controlled by the hydrogeologic parameters of the medium such as the dispersion coefficient, pore water velocity, retardation factor, degradation rate, mass transfer coefficient, water content, and fraction of dead-end pores. The breakthrough curve (BTC), which is the graphical relationship between the tracer concentration and the elapsed time since introduction, is an integrated picture of the hydrogeologic parameters that produced the BTC. Both radioactive and neutron-activatable tracers have been used to generate BTCs. The BTC of a 92 Br radioactive tracer generated under saturated conditions in a nonhomogeneous (fractured) soil column is shown. From BTCs, the effective hydrogeologic parameters can be identified if appropriate techniques are applied

Radioactive tracer system to indicate drill bit wear or failure

International Nuclear Information System (INIS)

Fries, B.A.

1975-01-01

A radioactive tracer system for indicating drill bit wear or failure utilizing radioactive krypton 85 in clathrate form, in the form of water-soluble kryptonates, or dissolved grease, is described. Preferably the radioactive krypton is placed so that when drill bit wear or failure occurs, the radioactive krypton 85 is relased and effectively becomes diffused in the circulating drilling fluid. At the surface, the radioactive krypton 85 gas is separated from the circulating drilling fluid by gas-mud separating means and is transported as a gas to a counting chamber where an accurate radioactivity count of beta rays released from the krypton is obtained. (Patent Office Record)

Radioactive tracer technique in process optimization: applications in the chemical industry

International Nuclear Information System (INIS)

Charlton, J.S.

1989-01-01

Process optimization is concerned with the selection of the most appropriate technological design of the process and with controlling its operation to obtain maximum benefit. The role of radioactive tracers in process optimization is discussed and the various circumstances under which such techniques may be beneficially applied are identified. Case studies are presented which illustrate how radioisotopes may be used to monitor plant performance under dynamic conditions to improve production efficiency and to investigate the cause of production limitations. In addition, the use of sealed sources to provide information complementary to the tracer study is described. (author)

Radioactive or natural tracer techniques for leak determining of dam abutment

International Nuclear Information System (INIS)

Chen Jiansheng; Du Guoping; Zheng Zheng; Sun Jing

1995-01-01

Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes, meanwhile interconnection between boreholes and the observing water points is analysed. The theory and practice of radioactive tracer synthetic detective method are described to give methods and calculation formulae used under the condition of stable flow in single well to measure permeability coefficient and hydrostatic heads. Major single hole techniques including measurement for seepage line, velocity, rate of seepage flow and relationship of recharge of groundwater in aquifers are introduced briefly. The possibilities offered by natural tracers are analysed, including electric-conduct, ph-value and temperature of water as well as stable isotopes (D, 18 O) and tritium. Furthermore, the sensibilities of this theory and methods were confirmed by detecting seepage flow field of Xinanjiang Dam

Study of movement of fly ash by radioactive tracer studies at Ennore Thermal Power Station (Tamil Nadu)

Energy Technology Data Exchange (ETDEWEB)

Ghosh, L K; Dange, A P

1982-01-01

This paper presents a study of the movement of fly ash from the Thermal Power Station at Ennore dumped in the ocean. The purpose of the study was to ensure that the ash dumped in the sea does not find its way to intake of the power station through the mouth of the river situated at a distance of 2 kms north. In such situations the use of radioactive tracer studies is found to be very effective and these studies indicated the necessity of dumping the fly ash beyond 6 m depth in the sea.

Study of movement of fly ash by radioactive tracer studies at Ennore Thermal Power Station (Tamil Nadu)

Energy Technology Data Exchange (ETDEWEB)

Ghosh, L K; Dange, A P [Central Water and Power Research Station, Pune (India)

1982-01-01

This paper presents a study of the movement of fly ash from the Thermal Power Station at Ennore dumped in the ocean. The purpose of the study was to ensure that the ash dumped in the sea does not find its way to intake of the power station through the mouth of the river situated at a distance of 2 kms north. In such situations the use of radioactive tracer studies is found to be very effective and these studies indicated the necessity of dumping the fly ash beyond 6m depth in the sea.

Simplification of complex kinetic models used for the quantitative analysis of nuclear magnetic resonance or radioactive tracer studies

International Nuclear Information System (INIS)

Schuster, R.; Schuster, S.; Holzhuetter, H.-G.

1992-01-01

A method for simplifying the mathematical models describing the dynamics of tracers (e.g. 13 C, 31 P, 14 C, as used in NMR studies or radioactive tracer experiments) in (bio-)chemical reaction systems is presented. This method is appropriate in the cases where the system includes reactions, the rates of which differ by several orders of magnitude. The basic idea is to adapt the rapid-equilibrium approximation to tracer systems. It is shown with the aid of the Perron-Frobenius theorem that for tracer systems, the conditions for applicability of this approximation are satisfied whenever some reactions are near equilibrium. It turns out that the specific enrichments of all of the labelled atoms that are connected by fast reversible reactions can be grouped together as 'pool variables'. The reduced system contains fewer parameters and can, thus, be fitted more easily to experimental data. Moreover, the method can be employed for identifying non-equilibrium and near-equilibrium reactions from experimentally measured specific enrichments of tracer. The reduction algorithm is illustrated by studying a model of the distribution of 13 C-tracers in the pentose phosphate pathway. (author)

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.

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.

Using radioactive tracers for the evaluation of industrial equipment

International Nuclear Information System (INIS)

Brandao, Luis Eduardo Barreira; Sa, Lidia Vasconcellos de; Sousa, Alvaro Serafim F. de

2000-01-01

This paper presents the radioactive tracer technique, giving as example some cases of the possible utilization developed by the Nuclear Engineering Institute, RJ, BR (Argonaut reactor) and through charged particle (CV-28 cyclotron), and also his production and aspects of radiological safety

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

Buried pipeline leak-detection technique and instruments using radioactive tracers

International Nuclear Information System (INIS)

Zhou Shuxuan; Lu Qingqian; Tang Yonghua

1987-01-01

For detecting and locating leaks on buried pipelines, a leak-detection technique and related instruments have been developed. Some quantity of fluid mixed with a radioactive tracer is injected. After the pipeline is cleaned, a leak-detector is put into and moves along the pipline to monitor the leaked radioactivity and to record both the radioactive signal and the time signal on a magnetic tape. From the signal curves, it can be judged whether there are any leaks on the pipeline and, if any, where they are

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)

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

Study of the migration of metallic micropollutants in the soils by means of radioactive tracers

International Nuclear Information System (INIS)

Jacquemet, P.

1995-01-01

The aim of this work was to study the migration of metallic micropollutants using radioactive tracers. Three experimental techniques were employed to show the interaction phenomena linked to these migrations. First, a simple batch characterization allows the qualitative and quantitative evaluation of the sorption-desorption of the micropollutants on the soils. Next, an elution technique applied to soil columns was introduced to study the behavior of the pollutants in hydrodynamic conditions. Finally, a series of lysimetric pots were prepared to extend the experiment to systems which mimic a natural environment. The tests were conducted in a hot laboratory with five agricultural soils and seven pollutants ( 57 Co, 134 Cs, 123m Te, 109 Cd, 144 Ce, 85 Sr and 110m Ag). The batch measurements (kinetics, K d sorption ratio at equilibrium and isothermal measurements according to the Langmuir or Freundlich models) allowed for a better understanding of the sorption-desorption mechanisms of the micropollutants. Their migration on continuously percolated columns (breakthrough curves and determination of the radioactive profiles in the soils) was evaluated and expounded together with the results obtained from the batch characterization. The profiles of the radioactive tracers in the soils of the lysimeters (with or without vegetation) were also determined. All these observations were used to characterize the migration properties of the micropollutants in the investigated soils. A simple simulation model of the migration of interactive solutes in porous media based on dispersion and convection was also applied to the experimental data. The calculated profiles showed fairly good agreement with the experimental ones, especially in the case of unplanted systems. Several parametric adjustments were, however, necessary. It was shown, finally, that simulations, as perfect as they could be, can seldom replace the experimental studies of the behaviour of micropollutants in the

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

Collection and processing of information in biological kinetics studies with radioactive tracers

International Nuclear Information System (INIS)

Remy, J.; Lafuma, J.

1968-01-01

The authors present an automatic method for the collection and treatment of information in biological kinetics experiments using radioactive tracers. The recording are made without any time constant on magnetic tape. The information recorded is sampled by a 400 channel multi-scale analyzer and transferred to punched cards. The digital analysis is done by an I.B.M. computer. The method is illustrated by an example: the hepatic fixation of colloidal gold in the pig. Its advantages and requirements are discussed. In the appendix are given the FORTRAN texts for two programmes used in treating the example presented. (authors) [fr

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

Study of solid phase kinetics during cyanidation using the 198 Au radioactive tracer

International Nuclear Information System (INIS)

Barbus, A.; Pop, I.I.; Gaspar, E.

1995-01-01

During cyanidation, the various gold bearing pyrite sorts exhibit different behaviour, that sometimes cause increased cyanidation times influencing the reagent and power consumption, in the same time generating fluctuations in the recovery efficiencies. The introduction of the 198 Au radioactive tracer into the cyanidation circuit enabled us to follow several parameters of the cyanidation kinetics: the average residence time of the gold bearing pyrite in the technological equipment, information about the homogenization process, dispersion of solids and gold dissolution efficiency on each technological stage. (author)

Brain regional uptake of radioactive Sc, Mn, Zn, Se, Rb and Zr tracers into normal mice during aging

International Nuclear Information System (INIS)

Amano, R.; Enomoto, S.

2001-01-01

Radioactive multitracer technique was applied to study the brain regional uptake of trace elements by the normal mice during aging. The brain regional radioactivities of 46 Sc, 54 Mn, 65 Zn, 75 Se, 83 Rb and 88 Zr were measured 48 hours after intraperitoneal injection of a solution in normal mice aged 6 to 52 weeks to evaluate the brain regional (corpus striatum, cerebellum, cerebral cortex, hippocampus, and pons and medulla) uptakes. The radioactive distributions of 46 Sc, 54 Mn and 88 Zr tracers were variable and region-specific in the brain, while those of 65 Zn, 75 Se and 83 Rb tracers were comparable among all regions of interest. The brain regional uptakes of all tracers slightly increased with age from 10 to 28 weeks, and then remained constant during aging after 28 weeks. These uptake variations may be involved in the functional degenerative process of the blood-brain barrier during aging. (author)

Concentration dynamics in lakes and reservoirs, studies using radioactive tracers

International Nuclear Information System (INIS)

Gilath, C.

1979-01-01

The concentration dynamics in lakes and reservoirs through which water flows can be investigated by injecting a pulse of radioactive tracer and measuring the response at the outlet or any other point of interest inside the lake. The methodology developed for this Kind of investigation is presented. It was found that concentration dynamics in shallow reservoirs can be described by a model consisting of a time delay in series with one or two time constants. Procedures for the determination of the volumes of these regions are presented for reservoirs considered as either constant or variable parameter systems. The flow pattern in the reservoirs was investigated by measuring the response of the concentration through the lake and was analyzed in relation to the prevailing wind conditions. Wind induced currents have a dominant influence on the flow pattern. (Author) [pt

Determination of viscosity in recirculating fluidized bed using radioactive tracer

International Nuclear Information System (INIS)

Silva, G.G. da.

1986-01-01

The use of radioactive tracer for measuring viscosity is proposed. The methodology relates the terminal velocity of a radioactive sphere in interior of fluid with the viscosity, which can be a fluidized bed or total flow of solids. The arrangement is composed by two γ detectors placed externally and along the bed. Both detectors are coupled by amplifier to electronic clock. The drop time of sphere between two detectors is measured. The bed viscosity two detectors is measured. The bed viscosity is calculated from mathematical correlations of terminal velocity of the sphere. (M.C.K.)

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

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

Study of lag time of river chenab between marala barrage and khanki headworks using radioactive tracer technique

International Nuclear Information System (INIS)

Ahmed, A.; Tariq, J.A.; Ahmad, N.; Iqbal, N.

2001-05-01

During the flood season, sometimes discharge peaks in two tributaries of the Indus River System coincide at the point of confluence and their cumulative effect threatens the downstream barrage/headworks. Reasonably accurate lag time (transit time) between different control points in relation to discharge helps mange flood routing more safely. As a part of S tudy of Lag Time of the Indus River Suystem , radioactive tracer experiment was conducted to determine the lag time between Marala Barrage and Khanki Headworks at the river Chenab. Discharge data shows that the maximum flood peak appears in August. In the monsoon period of the year 1999 the floods were low. So the radiotracer experiment was carried out at low discharge of about 538 m/sup 3/ sec/sup-1/ (19000 cusecs). An activity of about 2 Ci of /sup 82/Br radioactive tracer was injected instantaneously in the river at Marala on 1st September 1999 at 0640 hours. Monitoring of radioactivity by scintillation detectors (sodium iodide) was done at Khanki Headworks. The peak value of activity was found on September 2, 1999 at 0005 hours. The lag time was determined as 17 hours and 25 minutes. At this discharge level the river water travelled with the average speed of 3.69 km/hr. (author)

Solute movement observation in the field soils by means of radioactive tracers

International Nuclear Information System (INIS)

Lichner, L.

1986-01-01

The radioactive tracer method is discussed as applied to transfer velocity measurements of solutions in unsaturated soils, its applicability and the criteria for the choice of the tracer. The method is based on measurement of the radioactive tracer velocity in the field and on laboratory determination of the equilibrium distribution coefficients of the tracer and the solute in the same field soil. From these results and from the soil characteristics (porosity, bulk density) the solute transfer velocity in the field soil can be calculated. The results are presented of 131 I - velocity measurements in the loamy soil in the region of water source Cunovo near Bratislava, which equals 9.29x10 -9 m/s, and in the downstream slope of the earth dam Rozgrund near Banska Stiavnica where the velocity of 131 I - near the dam foot was found to be 2.03 - 2.86 times greater than near the top. Results are also presented of 131 I - , [ 60 Co-EDTA] - and 60 Co 2+ velocity measurements in clay-loam soil at the experimental field of the Research Institute of Irrigation in Most near Bratislava. The results are applicable to evaluation of surface damage to embankments and earth dams, to determination of the conservation zone around water sources, and the establishment of the level of ground water pollution from different sources (waste disposal, agriculture, etc.)

Semianalytical solutions of radioactive or reactive tracer transport in layered fractured media

International Nuclear Information System (INIS)

Moridis, G.J.; Bodvarsson, G.S.

2001-01-01

In this paper, semianalytical solutions are developed for the problem of transport of radioactive or reactive tracers (solutes or colloids) through a layered system of heterogeneous fractured media with misaligned fractures. The tracer transport equations in the matrix account for (a) diffusion, (b) surface diffusion (for solutes only), (c) mass transfer between the mobile and immobile water fractions, (d) linear kinetic or equilibrium physical, chemical, or combined solute sorption or colloid filtration, and (e) radioactive decay or first order chemical reactions. Any number of radioactive decay daughter products (or products of a linear, first-order reaction chain) can be tracked. The tracer-transport equations in the fractures account for the same processes, in addition to advection and hydrodynamic dispersion. Additionally, the colloid transport equations account for straining and velocity adjustments related to the colloidal size. The solutions, which are analytical in the Laplace space, are numerically inverted to provide the solution in time and can accommodate any number of fractured and/or porous layers. The solutions are verified using analytical solutions for limiting cases of solute and colloid transport through fractured and porous media. The effect of important parameters on the transport of 3 H, 237 Np and 239 Pu (and its daughters) is investigated in several test problems involving layered geological systems of varying complexity. 239 Pu colloid transport problems in multilayered systems indicate significant colloid accumulations at straining interfaces but much faster transport of the colloid than the corresponding strongly sorbing solute species

Interaction of 1-iodochlordecone, as radioactive tracer, with the carboxylate group on activated carbon

International Nuclear Information System (INIS)

Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Jáuregui-Haza, Ulises Javier

2016-01-01

Chlordecone is a synthetic organo chlorinated compound that has been used as pesticide. It has been identified and listed as persistent organic pollutant by the Stockholm Convention. The use of activated carbon filters is one of the most widely popular solutions for water decontamination. The chlordecone labeled with radioactive iodine (1-iodochordecone) is a potential radioactive tracer for studying adsorption, environmental availability and bio-distribution of chlordecone. The selection of the best suited activation carbon for this type of contaminants is mainly an empiric process, increasing the costs of research. A simplified activation carbon model, consisting of a seven ring graphene sheet with a functional group (carboxylate) was used to assess the interaction of chlordecone and 1-iodochlordecone with this surface group under neutral pH conditions over the adsorption process. The Multiple Minima Hypersurface methodology with the semiempirical Hamiltonian PM7 was used. The results indicate that for carboxylate, in neutral conditions, significant associations appear which suggest chemisorption in activated carbon. No significant differences were observed for the interactions of chlordecone and 1 iodochlordecone with carboxylate, making 1-iodochlordecone a good candidate as a radioactive tracer in medical research. (author)

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)

Radioactive tracers in the assessment of cleaning of surgical appliances

International Nuclear Information System (INIS)

Mostafa, A.B.M.G.; Chackett, K.F.

1975-01-01

Radioactive tracers which may be used in the assessment of cleaning of surgical appliances are described. Five labelled compounds were used as soiling material and tested in the rather severe conditions that exist during cleaning cycles. Measurements of decontamination in two cases were considered reliable but in the other three some degree of decomposition of the soil occurred, which falsified the results. (author)

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

Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers

International Nuclear Information System (INIS)

Russow, R.; Knappe, S.

1999-01-01

Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and 15 N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D 2 O, bromide and [ 15 N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers [de

Bottom sediment transport by radioactive tracer techniques off a stretch of the southern coast from Sao Paulo State - Brazil

International Nuclear Information System (INIS)

Bomtempo, V.L.

1995-01-01

This paper presents the methodology and results obtained with radioactive tracer techniques as applied to study sea-bottom sediments movements off a stretch of the southern coast of Sao Paulo State, Brazil, namely Praia do Una. Three injections of ground glass containing Iridium-192 were made and the behaviour of this material was tracked by special detection techniques, as it was acted upon by hydrodynamic agents, in two distinct periods of the year of 1982 (summer and winter). Measurement of hydrodynamic parameters was conducted simultaneously with tracer experiments. From the experiments with radioactive tracers, combined with other conventional studies, qualitative and quantitative conclusions could be drawn, as follows: waves are the prevailing agents in moving bottom sediments; during summer time, onshore and alongshore transport can be identified; during winter time, offshore and alongshore transport are present; for summer conditions, Massif transport rate was estimated to be 150 kg m -1 day -1 . (author). 2 refs, 3 figs

Study of seepage losses from irrigation canals using radioactive tracer technique

International Nuclear Information System (INIS)

Ahmad, M.; Tariq, J.A.; Rashid, A.; Rafiq, M.; Iqbal, N.

2004-06-01

wetted area of the canal. The radiotracer (/sup 99m/Tc) having very short half-life (6 hrs) poses no health hazards as it decays in one day after traveling a very short distance, at the most a few meters. A very small quantity of the tracer required for a test can be met from the leftover activity of /sup 99m/ Tc imported for medical centers. However ECNEC has approved a project produce. /sup 99m/Tc locally at PINSTECH which will ensure its availability at competitive cost. In this study it has been proven that radioactive tracer technique can be used to determine seepage losses from distributaries to biggest canal either unlined or lined in running condition without its closure or disturbing flow. Cost per test based on few tests is about Rs. 100,000/-which could be reduced to Rs. 60,000/-per test for the large scale investigations by creating facilities for drilling and fabrication of filters. The seepage tests can be repeated at the same locations using the existing wells at a cost of Rs. 15000/-. Therefore, this technique is also useful to evaluate the effectiveness of the lining or any other remedial measure. Considering the accuracy of the radiotracer technique and availability of facilities at reasonable cost, this novel technique may be applied at national level. (author)

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

Production of calibration sources and/or radioactive tracers with the cyclotron CV-28

International Nuclear Information System (INIS)

Osso Junior, Joao Alberto

1995-01-01

The present stage of production of calibration sources and radioactive tracers with the Cyclotron CV-28 is described. Among the methods already developed special attention is given to the production of 57 Co, 109 Cd and 111 In. (author). 3 refs

Use of 65 Zn as radioactive tracer in the bioaccumulation study of zinc by aquatic organisms

International Nuclear Information System (INIS)

Malagrino, W.

1992-01-01

The present work has as main objective to emphasize the importance of using radioactive tracers as well as to establish a methodology for the utilization of 65 Zn in the bioaccumulation study of zinc by Poecilia reticulata. The exposure time varied from 5 days (short term experiments) to 30 days (long term experiments). The bioaccumulation of zinc from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 65 Zn which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behaviour of the stable zinc since the radionuclide used is an isotope of the same element and therefore presents the same chemical properties. (author)

Radiological safety methodology in radioactive tracer applications for hydrodynamics and environmental studies; Metodologia de la seguridad radiologica en el empleo de trazadores radiactivos en estudios hidrodinamicos e ingenieria ambiental

Energy Technology Data Exchange (ETDEWEB)

Suarez, R; Badano, A; Dellepere, A; Artucio, G; Bertolotti, A [Nuclear Technology National Direction, Montevideo (Uruguay)

1995-07-01

The use of radioactive tracer techniques as control sewage disposal contamination in Montevideo Estuarine and Carrasco beach has been studied for the Nuclear Technology National Direction. Hydrodynamic models simulation has been introduced as work methodology. As well as radiological safety and radioactive material applications in the environmental studies has been evaluated mainly in the conclusions and recommendations in this report. maps.

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

Study of cation diffusion in Zn O using 65Zn as radioactive tracer

International Nuclear Information System (INIS)

Ferraz, Wilmar B.; Correa, Ricardo F.; Nogueira, Maria A.N.; Ramos, Marcelo; Sabioni, Antonio C.S.

2000-01-01

Zinc self-diffusion coefficient were measured in polycrystalline Zn O of high purity (99,999%) prepared by conventional sintering at 1393 deg C, 4 h, in oxygen atmosphere. The Zn O samples had high density (>99% of the theoretical density) and grain size of 20 μm. These samples were resintered for 72 h at 1400 deg C in order to increase the grain-size higher than 50 μ m. Samples of 15 x 15 x 2 mm 3 were polished with diamond paste, and pre-annealed under the same conditions of temperature and atmosphere of the diffusion annealing. A thin film of 65 Zn - radioactive tracer - applied to the polished surface was oxidized in oxygen atmosphere for a short time before diffusion annealing. The diffusion experiments were performed between 1002 and 1201 deg C in oxygen atmosphere. The 65 Zn diffusion profiles were measured by sectioning in conjunction with residual-activity measurements. The results of the determination of the zinc in Zn O diffusion coefficients in function of temperature are presented and a comparison of these results obtained by the two radioactive method is showed. (author)

The use of a radioactive tracer for the determination of distillation end point in a coke oven

International Nuclear Information System (INIS)

Burgio, N.; Capannesi, G.; Ciavola, C.; Sedda, F.

1995-01-01

A novel high precision detection method for the determination of the distillation end point of the coking process (usually in the 950 deg C range) has been developed. The system is based on the use of a metallic capsule that melts at a fixed temperature and releases a radioactive gas tracer ( 133 Xe) in the stream of the distillation gas. A series of tests on a pilot oven confirmed the feasibility of the method on industrial scale. Application of the radioactive tracer method to the staging and monitoring in the coking process appears to be possible. (author). 6 refs., 5 figs., 3 tabs

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)

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)

Present stage of the use of radioactive tracers in studies carried out at Companhia de Tecnologia de Saneamento Ambiental, SP, Brazil, in the field of environmental engineering

International Nuclear Information System (INIS)

Sanchez, W.; Agudo, E.G.

1979-01-01

Studies using radioactive tracers in the field of environmental engineering, carried out at Companhia de Tecnologia de Saneamento Ambiental, SP, Brazil, from 1975 to 1978 are presented. Future research to be developed in this area is also discussed. (M.A.) [pt

Evaluation of urban and industrial wastewater treatment plants using radioactive tracers

International Nuclear Information System (INIS)

Brandao, Luis Eduardo Barreira

2001-07-01

A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as 82 Br ( for the liquid phase), 110m Ag and 140 La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time γ, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

The application of radioactive tracers for determination of bed-load transport in alluvial rivers

International Nuclear Information System (INIS)

Thomsen, T.

1980-01-01

Radioactive isotopes have been applied for determining the transport rate of bed load in an alluvial river on the basis of: centroid velocity of the tracer particles, size and material-transporting width of mobile layer. These parameters were found by detailed measurements in the field. Computed values were produced on the basis of Engelund and Fredsoee's model on sediment transport and on the propagation of bed forms. When comparing measured and computed values, the difference was about 25%. Finally, the applicability of tracer methods for solving practical problem is discussed. (author)

Deactivation of tracer-flo equipment thru retrieval of its radioactive Krypton-85 gas

International Nuclear Information System (INIS)

Domondon, D.B.; Rara, R.B.; Borras, A.M.

1994-01-01

Tracer-flo equipment must be cleared of Krypton-85 before these can be transported. The rules and regulations on safe transport of radioactive materials require Kr-85 gas to be transported in an approved container. A new innovative technique/procedure in deactivating tracer-flo equipment i.e., without separation of the Kr-85 from the nitrogen was developed by the authors. The developed procedure was successfully applied in four tracer-flo equipment of three (3) semiconductor firms. In the process, the three firms have saved about US$ 28,000.00 (P 800,000.00) if the deactivation were undertaken by a foreign service company. The Philippine Nuclear Research Institute (PNRI) retrieved about P 382,000.00 worth of Kr-85 that could be used in industrial applications such as leak tracing of buried pipes, etc. (author). 1 ref.; 5 figs

Optimization of copper ore concentration processing by means of radioactive tracers

International Nuclear Information System (INIS)

Petryka, L.; Przewlocki, K.

1989-01-01

Flotation of polymetallic ores in the Polish Lower Silesian Basin was taken as an example for the optimization of copper ore processing using radioactive tracers. An original stochastic mathematical model (stream model) was proposed to minimize copper losses in tailing. A detailed procedure of measurement is presented as well as the experimental data and their interpretation. On the basis of this research copper losses in tailing can be reduced to one third. (author)

Study of the source-detector system geometry using the MCNP-X code in the flowrate measurement with radioactive tracers

Energy Technology Data Exchange (ETDEWEB)

Avilan Puertas, Eddie, E-mail: epuertas@nuclear.ufrj.br [Universidad Central de Venezuela (UCV), Facultad de Ingenieria, Departamento de Fisica Aplicada, Caracas (Venezuela, Bolivarian Republic of); Braz, Delson, E-mail: delson@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Brandao, Luis E.; Salgado, Cesar M., E-mail: brandao@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

The use radioactive tracers for flow rate measurement is applied to a great variety of situations, however the accuracy of the technique is highly dependent of the adequate choice of the experimental measurement conditions. To measure flow rate of fluids in ducts partially filled, is necessary to measure the fluid flow velocity and the fluid height. The flow velocity can be measured with the cross correlation function and the fluid level, with a fluid level meter system. One of the error factors when measuring flow rate, is on the correct setting of the source-detector of the fluid level meter system. The goal of the present work is to establish by mean of MCNP-X code simulations the experimental parameters to measure the fluid level. The experimental tests will be realized in a flow rate system of 10 mm of diameter of acrylic tube for water and oil as fluids. The radioactive tracer to be used is the {sup 82}Br and for the detection will be employed two 1″ NaI(Tl) scintillator detectors, shielded with collimators of 0.5 cm and 1 cm of circular aperture diameter. (author)

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

Study of hydraulic parameters in leach mining using radioactive tracer

International Nuclear Information System (INIS)

Ahmad, M.; Tariq, J.A.; Iqbal, N.; Rafiq, M.

2002-01-01

Six radioactive tracer (/sup 131/I) experiments were carried out at in-situ leach mining site to study transit time of injected fluid from the injection wells to the production well along the dip, against the dip, along the diagonals and the strike. It was found that the dip of the host sandstone does not affect the movement of fluid as the same velocity was found along the dip (0.23 m/h) and against the dip (0.22 m/h). Along the diagonals, the breakthrough times for 13.75 m and 16.25 m were 54 hours and 155 hours respectively yielding velocities of 0.26 m/h and 0.1 m/h. The higher velocity is not only due to shorter distance but also due to higher porosity / injection rate. Along the strike, the breakthrough time was 29 hours (very short) for 9.25 m distance and 147 hours for 16.25 m distance. The unexpectedly high velocity along the strike for shorter distance was also due to higher injection rate in the well as the other well was accepting only small fraction of the total injection. At higher injection/production rate or higher hydraulic gradient, the breakthrough time is shorter and also the dispersion of fluid is less, consequently the leach area would be relatively small. Fluctuations of activity in some cases show the presence of fractures/cracks at certain places in the strata. The estimated porosity and hydraulic conductivity of the aquifer are 28% and 1.23 x 10-5 m/s respectively. (author)

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

A contribution to the study of radioactive waste dilution in the Rhone involving tests with a rhodamine B tracer

International Nuclear Information System (INIS)

Rodier, J.; Marichal, M.

1961-01-01

The process whereby waste from the Marcoule plant mixes with the water in the Rhone was followed in tests with rhodamine as a chemical tracer. Satisfactory dispersion was noted less than 4 km downstream from the waste discharge duct outlet, and the degree of homogeneity was considered to be satisfactory at the bridge of Roquemaure, und perfect at Avignon. This investigation not only revealed a complete absence of any preferential flow paths containing high radioactive waste concentrations, but it also enabled the most representative points to be selected at which to take Rhone water samples during future radioactive waste discharges. Reprint of a paper published in 'La Houille Blanche' N. 5 - Aug 196, p. 636-641 [fr

A concept for limiting the number of radioactive tracer experiments in a factory plant

International Nuclear Information System (INIS)

Monchy, A.R. de

1980-01-01

There are currently no restrictions regarding the quantities of radioactive material stored, used or discharged in factories where radioactive tracer experiments are performed. This article describes a concept for such restrictions, based on two criteria - 1) a system of standards for the absorption of the contamination by either water or air, dependent on the half life of the nuclides used and 2) a summation procedure of the activities of the nuclides used, the activities being weighed by the toxicity and chance of spreading of each nuclide. (C.F.)

Quantitative determination of sediment movement at the landward spoil ground in the Yangtze Estuary with radioactive tracer

International Nuclear Information System (INIS)

Li Zhangsu

1993-01-01

A radioactive tracer experiment was carried out at the landward spoil ground of the North Passage in the Yangtze Estuary in June of 1991. The scandium-46 was selected as the tracer, the total activity released is 17.95 x 10 10 Bq(4.85 Ci), the amount of the scandium-46 glass is 495 g. The purpose of the experiment is to determine the sediment movement direction, path, velocity and transport rate. The experiment provides the direct evidence for using the landward spoil ground in the future. The experiment results show the sediment movement was governed by the ebb tide current during the period of middle and neap tides when the radioactive tracer was injected both on the flood and ebb tides, and the sediment moved from the injection points to the middle of the North Passage near the navigation buoy No. 269. The direction of the sediment movement is 110 degree, the particle velocity is 758 m/d, and the sediment transport rate per unit width is 47.8 m 3 /md

Using radioactivity

International Nuclear Information System (INIS)

1982-10-01

The leaflet discusses the following: radioactivity; radioisotopes; uses of ionising radiations; radioactivity from (a) naturally occurring radioactive elements, and (b) artificially produced radioisotopes; uses of radioactivity in medicine, (a) clinical diagnostic, (b) therapeutic (c) sterilization of medical equipment and materials; environmental uses as tracers; industrial applications, e.g. tracers and radiography; ensuring safety. (U.K.)

Numerical Simulation of a Tracer Experiment at the Wolsong Nuclear Site

International Nuclear Information System (INIS)

Jeong, Hyojoon; Kim, Eunhan; Park, Misun; Jeong, Haesun; Hwang, Wontae; Han, Moonhee

2014-01-01

By comparing the concentration of a tracer measured under weather conditions that are disadvantageous to the dilution of radioactive materials released from the Wolsong Nuclear Power Plant, with the concentration of a tracer calculated using an air Dispersion model, it is possible to evaluate the characteristics of the air concentrations of radioactive materials estimated with an air Dispersion model, which can then be used in an environmental impact analysis of radioactive materials. Therefore, a field Dispersion experiment has been carried out to figure out the behavioral characteristics of the tracer under weather conditions that are disadvantageous to the dilution of radioactive materials released from the Wolsong Nuclear Power Plant site in Korea. In addition, through a comparison of the tracer concentrations estimated by the Gaussian plume model with measurements, this study checked the degree of conservative estimation for the Gaussian plume at the Wolsong nuclear site in Korea. A tracer Dispersion experiment using an SF 6 trace was implemented to determine the Dispersion characteristics of radioactive materials at the Wolsong Nuclear Power Plant site in Korea. Based on meteorological data and the emission rate of the tracers, this study estimated the tracer concentrations using a Gaussian plume model, and then compared it with the measurement to check the conservative estimation of the Gaussian plume model. The measured concentrations of the tracer tends to be lower than the concentrations estimated by the Gaussian plume model overall

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

The application of mathematical models for the evaluation of radioactive tracer tests carried out in South Africa

International Nuclear Information System (INIS)

Snyman, G.C.; Smith, S.W.

1975-12-01

The application of mathematical models to evaluate tracer experiments is illustrated by examples of tests done in a variety of industrial plants, using radioactive tracers. Two basic models, the axial mixing model and the perfectly mixed tank model, as well as various applicational techniques, are described. It is concluded that many processes can be simulated to various degrees of accuracy by using the basic models, and that both quantitative and qualitative information can be obtained about the process [af

The use of radioactive tracers in medicine. Part 2. The development of devices for imaging radionuclides

International Nuclear Information System (INIS)

Bailey, D.L.

1996-01-01

Tracer techniques have been used in medical research for more that two centuries. The history of the measurement of radiotracer in vivo is presented starting with non-imaging, quantitative measurements, and continuing with gamma cameras through to PET scanners. The latest represent the state-of-the-art due to the combination of in-vivo use of tracers with medical tomographic imaging. Its ability to correct accurately for attenuation makes it potentially quantifiable in radioactivity concentration terms and from this follows the ability to determine biological parameters non-invasively. 8 refs., 1 tab. 3 figs

Air pollution tracer studies in the lower atmosphere (citations from the NTIS data base). Report for 1964-Jan 80

International Nuclear Information System (INIS)

Cavagnaro, D.M.

1980-02-01

The cited reports cover research on the use of tracers to study lower atmospheric air pollution movements. The tracer used include sulfur hexafluoride, krypton 85, carbon 14, and other radioactive isotopes. The studies cite the results and techniques used, tracer movement from nuclear power plants, industrial stacks, urban areas, and the detectors used in their measurement

Determination of the resident time distribution (RTD) in copper concentrate drying plants using radioactive tracers

International Nuclear Information System (INIS)

Diaz V, Francisco J.; Duran P, Oscar U.; Hernandez A, Fernando A.

1996-01-01

This paper is a study on the drying process of copper concentrate, on two fluidized bed dryers at Fundicion Caletones, Division El Teniente, Codelco-Chile. The problem was investigated by experimental determination of the resident Time Distribution (RTD) for the material to be dry and by an analysis of the influence of the grain size in the drying process. The stimulus-response technique was used in the experiments, where the stimulation was a pulse of an adequate radioactive tracer injected at the dryer's input. Under these conditions, the response obtained at the dryer's outputs, i.e., the concentration variation curve as a function of time, represents directly the RTD of the system between the injection and measuring points. The tracer used was the same material to be dried, and it was irradiated with neutrons in the nuclear reactor at La Reina Nuclear Centre, thus producing a solid gamma radiation emitter tracer of identical behaviour as the material under study. The approximate activity of each sample was equivalent to 8 mCi of Cu-64 at the time of the injection and the measurement of the tracer was made on-line using NaI(Tl) gamma radiation detectors. The results obtained showed average times less than the estimated and would indicate a fast drying using minimum volume in the dryer. The drying of the fine particles was three times faster than the coarse ones. (author)

Compartmental Modeling and Dosimetry of in Vivo Metabolic Studies of Leucine and Three Secretory Proteins in Humans Using Radioactive Tracers

Science.gov (United States)

Venkatakrishnan, Vaidehi

1995-01-01

Physical and mathematical models provide a systematic means of looking at biological systems. Radioactive tracer kinetic studies open a unique window to study complex tracee systems such as protein metabolism in humans. This research deals with compartmental modeling of tracer kinetic data on leucine and apolipoprotein metabolism obtained using an endogenous tritiated leucine tracer administered as a bolus, and application of compartmental modeling techniques for dosimetric evaluation of metabolic studies of radioiodinated apolipoproteins. Dr. Waldo R. Fisher, Department of Medicine, was the coordinating research supervisor and the work was carried out in his laboratory. A compartmental model for leucine kinetics in humans has been developed that emphasizes its recycling pathways which were examined over two weeks. This model builds on a previously published model of Cobelli et al, that analyzed leucine kinetic data up to only eight hours. The proposed model includes different routes for re-entry of leucine from protein breakdown into plasma accounting for proteins which turn over at different rates. This new model successfully incorporates published models of three secretory proteins: albumin, apoA-I, and VLDL apoB, in toto thus increasing its validity and utility. The published model of apoA-I, based on an exogenous radioiodinated tracer, was examined with data obtained using an endogenous leucine tracer using compartmental techniques. The analysis concludes that the major portion of apoA-I enters plasma by a fast pathway but the major fraction of apoA-I in plasma resides with a second slow pathway; further the study is suggestive of a precursor-product relationship between the two plasma apoA-I pools. The possible relevance of the latter suggestion to the aberrant kinetics of apoA-I in Tangier disease is discussed. The analysis of apoA-II data resulted in similar conclusions. A methodology for evaluating the dosimetry of radioiodinated apolipoproteins by

Basic Description of the Lymphatic System from the Perspective of SLN Uptake of Radioactive Tracers. Chapter 2

International Nuclear Information System (INIS)

Pasqualini, R.; Janevik-Ivanovska, E.

2015-01-01

The lymphatic system is part of the circulatory system. It is closely associated with the cardiovascular system because it includes a network of vessels that contributes to liquid transportation throughout the body. This circulatory system is essential for the maintenance of interstitial fluid balance, uptake of dietary fat and for body defence against invasion by disease causing agents. Lymph nodes, which contain large numbers of B and T lymphocytes and macrophages, are located along lymphatic pathways. They have two primary functions: filtering and digesting potentially harmful particles from lymph before returning it to the bloodstream and contributing to the immune surveillance provided by lymphocytes and macrophages. In their function of filtering particles or cell debris, lymph nodes may collect cancer cells that are breaking and travelling away from the primary tumour. The spread of some forms of cancer usually follows an orderly progression, spreading first to regional lymph nodes, then the next rank of lymph nodes and so on. Therefore, the first lymph node (the SLN) is more likely than other lymph nodes to contain cancer cells. If a suitable radioactive tracer, generally a nanocolloid or a dye, is administrated in the proximity of the tumour site, it will travel through the lymphatic system and be trapped in the SLN, allowing its localization using an appropriate probe or by visual determination. The size and the charge of the radioactive tracer will mainly influence the extent of radioactivity remaining at the site of injection, the rate of diffusion into the lymphatic vessels and the uptake in the SLN. Knowledge of the physiology of the lymphatic system will help to identify factors influencing the diffusion and uptake mechanism of radioactive tracers in the lymph nodes and will assist in the design of more efficient and selective SLN seeking drugs. (author)

Seepage determinations through auxiliary dike in Chingaza reservoir using radioactive tracers

International Nuclear Information System (INIS)

Sanches, L.; Obando, E.; Jimenez, G.; Torrez, E.

1986-01-01

Isotope techniques used in hydrology and developed during the last ten years in Colombia are usually tracer techniques based on the use of nuclides either introduced or naturally present in water. A problem of current content importance in hydraulics structures is seepage and the problems connected with it, such as impermeability of dams docks and their foundations. Many approaches are used to investigate these questions, but the simplest and most successful is the radiometric method. Radiometric observation of the flow of water through the earth dock involves introducing at a fixed point in the flow of water a radioactive solution and then following its movement downstream of the dock, and finding the place where it goes using appropriate detectors arranged at fixed control points. This paper describes the mean of choosing the injection points, the techniques for introducing radioactive solution and the conditions that must be borne in mind when selecting the radioisotope and determining its optimum activity. (author)

Five channel data acquisition system for tracer studies

International Nuclear Information System (INIS)

Narender Reddy, J.; Dhananjay Reddy, Y.; Dheeraj Reddy, J.

2001-01-01

Radioactive tracers are being used by many modern industries for trouble shooting, process control/quality control and optimization in the process plants. A five channel data acquisition system which has five independent scintillation detector based channels for data acquisition has been developed and made available. This system can be used for tracer studies involving Mean residence time, Resident time distribution and other similar parameters involving tracer movement. System developed can acquire data with dwell times ranging from 10 m sec to 100 sec into each channel and has a capacity to acquire data into 10K channels. Each channel electronics, has a 1x1 NaI Scintillation Detector probe, HV, AMP SCA, micro-controller based data acquisition card with independent dot matrix LCD display for visualization. Extensive use of serial bus (I 2 C, microwire) compatible devices has been incorporated in the design. Data acquisition is initiated simultaneously into all the channels. System design permits delayed/prompt data acquisition selectively. Dual counter switching technique has been employed to achieve faster dwell times for data acquisition. (author)

Determination of diffusion parameters using radioactive tracers, aiming at a project of a submarine sewage outfall

International Nuclear Information System (INIS)

Santos, J.L. dos.

1979-01-01

Radioactive tracers technology is applied to pollutant dispersion studies in water bodies, for the project of submarine sewage outfall. The models proposed by Hansen/Harremoes and Okubo, respectively, for the prediction of physical dilution rates and determination of turbulent diffusion laws, are discussed. The methodology for field work as well as data processing is described. The results from field investigations carried out in Brazilian litoral waters for submarine release of sewage in Santos - Sao Vicente, Guaruja and Maceio, are presented and commented. (Author) [pt

Using radioactive tracers for the evaluation of industrial equipment; Utilizacao de tracadores radioativos na avaliacao de equipamentos industriais

Energy Technology Data Exchange (ETDEWEB)

Brandao, Luis Eduardo Barreira; Sa, Lidia Vasconcellos de; Sousa, Alvaro Serafim F. de [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2000-07-01

This paper presents the radioactive tracer technique, giving as example some cases of the possible utilization developed by the Nuclear Engineering Institute, RJ, BR (Argonaut reactor) and through charged particle (CV-28 cyclotron), and also his production and aspects of radiological safety.

Methodology for the determination of underground water velocity, direction and flow, by using radioactive tracers

International Nuclear Information System (INIS)

Aoki, P.E.

1983-01-01

A basic route determining velocity and direction of ground water flow by using radioactive tracers is presented. Emphasis has been given to hydrology and nuclear energy concepts, to the construction of some specific equipment, to the calibration of radiation detectors and to the practical applications in borehole. 82 Br and 51 Cr have been chosen as tracers for the Darcy's velocity and direction determinations, respectively. From the obtained value of Darcy's velocity, the laminar flow was confirmed according to the admitted hypothesis. Comparisons of the Darcy's velocity values and flow direction have been made with values obtained using pumping tests and survey of the equipotential curves, where it can be concluded that they are of the same largeness and then, from a practical view, approximate. (Author) [pt

Study of leak detection using tracers in a bottling plant in Mexico

International Nuclear Information System (INIS)

Vizuet Gonzalez, Jorge; Reyes Jimenez, Jose Luis; Molina, Gustavo

2005-01-01

The Instituto Nacional de Investigaciones Nucleares (ININ), Mexico, promoted the application of different techniques, involving the use of radioactive materials. Among them is the use of radioactive material as a medium tracer in the industry. Below is a study of locating leaks in ducts collectors of process water of a bottling plant which had several problems, one was not able to stop production, and most important, having to disassemble a large amount of machinery and equipment, in order to open the floor and locate the leak

Field ionization mass spectrometry (FIMS) applied to tracer studies and isotope dilution analysis

International Nuclear Information System (INIS)

Anbar, M.; Heck, H.d'A.; McReynolds, J.H.; St John, G.A.

1975-01-01

The nonfragmenting nature of field ionization mass spectrometry makes it a preferred technique for the isotopic analysis of multilabeled organic compounds. The possibility of field ionization of nonvolatile thermolabile materials significantly extends the potential uses of this technique beyond those of conventional ionization methods. Multilabeled tracers may be studied in biological systems with a sensitivity comparable to that of radioactive tracers. Isotope dilution analysis may be performed reliably by this technique down to picogram levels. These techniques will be illustrated by a number of current studies using multilabeled metabolites and drugs. The scope and limitations of the methodology are discussed

Studies on radioactivity monitoring proceedure for marine organisms

International Nuclear Information System (INIS)

Koyanagi, Taku; Hirano, Shigeki

1978-01-01

Suitability of several species of mollusca and seaweeds as indicator organisms for radioactivity monitoring of marine environment was examined by radioisotope tracer experiments or stable elements analyses from the standpoints of the affinities for radionuclides, the sampling procedures, and the distribution of radioactive and stable elements in the body of these organisms. Extremely high concentration factor of 54 Mn was shown by kidney of scallop suggesting the suitability for the efficient monitoring of the nuclide though the contribution of kidney to the weight of scallop was very small. Higher concentration of 54 Mn in midgut gland rather than kidney was observed in the case of other species of shellfishes but distribution of the nuclide among organs or tissues of the organisms varied during the period of intake and excretion. Ununiform distribution of radioactive and stable elements among the species of seaweeds and in the body of seaweeds observed by the tracer experiments and stable element analyses suggested the necessity of careful selection of the samples for monitoring of these nuclides. From the results of tracer experiments carried out in order to elucidate the relation between existing state of radionuclides in seawater and uptake by marine organisms, it was supposed that the complexed forms with inorganic or organic ligands in seawater were predominant species of radioactive cerium in seawater. (author)

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

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

Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

Energy Technology Data Exchange (ETDEWEB)

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

1999-02-01

Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

Detection technique of radioactive tracer and its application to the flow problems

International Nuclear Information System (INIS)

Sato, Otomaru; Kato, Masao

1978-01-01

With a radioactive tracer experiment the nature of the system and the precision are the two key factors to determine the amount of the required tracer. It should be kept as low as possible to meet environmental regulations. The former factor is concerned with the isotope dilution during the experiment and the latter with counting techniques. In part 1, some counting techniques are investigated while three field experiments are described in part 2. Chemical treatments of water sample are described firstly in part 1. Recovery of the order of 95% was achieved with 24 Na, 131 I and 82 Br by either ion exchange or precipitation technique. Three direct γ-ray counting techniques are investigated secondly, e.g. dip counting method, pipe counting technique, and plane source counting technique. Thirdly, counting characteristics of a moving radioactive source was investigated. A small source was stuck on a moving belt and the center of a GM tube was faced to the belt. The counting rates with or without a collimator were analyzed using a simple equation. In part 2, the first experiment is on the flow rate of the Sorachi river in summer 1961. Measurements by an underwater detector and from periodically collected samples were compared at every observing stations. The second experiment was on the sorption loss of the isotopes in the river in 1963. Very little sorption loss was recognized with 82 Br, while a sorption loss of 10% was found with 24 Na after 6 km downflow. Isotopes were found to mix transversely after 7 to 10 km flow. The third experiment is concerned with the investigation on the movement of sediments at Okuma coast in Fukushima prefecture. (J.P.N.)

Ensemble-based simultaneous emission estimates and improved forecast of radioactive pollution from nuclear power plant accidents: application to ETEX tracer experiment

International Nuclear Information System (INIS)

Zhang, X.L.; Li, Q.B.; Su, G.F.; Yuan, M.Q.

2015-01-01

The accidental release of radioactive materials from nuclear power plant leads to radioactive pollution. We apply an augmented ensemble Kalman filter (EnKF) with a chemical transport model to jointly estimate the emissions of Perfluoromethylcyclohexane (PMCH), a tracer substitute for radionuclides, from a point source during the European Tracer Experiment, and to improve the forecast of its dispersion downwind. We perturb wind fields to account for meteorological uncertainties. We expand the state vector of PMCH concentrations through continuously adding an a priori emission rate for each succeeding assimilation cycle. We adopt a time-correlated red noise to simulate the temporal emission fluctuation. The improved EnKF system rapidly updates (and reduces) the excessively large initial first-guess emissions, thereby significantly improves subsequent forecasts (r = 0.83, p < 0.001). It retrieves 94% of the total PMCH released and substantially reduces transport error (>80% average reduction of the normalized mean square error). - Highlights: • EnKF is augmented for estimating emission and improving dispersion forecast. • The improved system retrieves 94% of the actual total tracer release in ETEX. • The system substantially improves the 3-h forecast of the tracer dispersion. • The method is robust and insensitive to the first-guess emissions. • The meteorological uncertainties exert strong influence on the performance

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

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)

Use of natural radioactive tracers for the determination of vertical exchanges in the planetary boundary layer

International Nuclear Information System (INIS)

Druilhet, A.; Guedalia, D.; Fontan, J.

1980-01-01

Methods for determining the vertical exchange coefficients in the planetary boundary layer using the natural radioactive tracers radon ( 222 Rn), thoron ( 220 Rn), and ThB( 212 Pb) are presented here. Thoron (T/sub 1/2/ = 54 sec) was used for the surface layer. The main results are given for two applications: vertical exchange studies above a flat country and inside a vegetable canopy. Owing to its lifetime, radon can be used for the nocturnal stabilities that have an important concentration increase near the ground. For the planetary layer (0 to 2000m), ThB(T/sub 1/2/ = 10.6 hr) was mainly used

Mercury bioaccumulation and elimination by Xenomelanires brasiliensis - radioactive tracers technique

International Nuclear Information System (INIS)

Malagrino, Waldir; Mesquita, Carlos Henrique de; Sousa, Eduinetty Ceci P.M. de

2002-01-01

The present work has as main objective to emphasized the importance of using radioactive tracers as well as to establish a methodology for the utilization of 203 Hg in the bioaccumulation study of mercury by X enomelanires brasiliensis. The exposure time was 168 hours. The bioaccumulation of mercury from the water as well as the elimination of the metal previously absorbed were determined by measuring the activity of 203 Hg, which was added to the water in the beginning of the experiments. The technique chosen is suitable to study the behavior of the stable mercury since the radioisotope used is an isotope of the same element and therefore presents the same chemical properties. The results obtained show that the absorption and elimination of mercury by Xenomelanires brasiliensis is slow, 168 hours being necessary for the elimination of 38 % of the previously absorbed mercury. The results are of main concern if it is considered that the literature about bioaccumulation of mercury by the Brazilian ichthyofauna is scarce. Furthermore the species Xenomelanires brasiliensis is part of the food chain and the results can be used in the evaluation of the potential risk of the mercury bioaccumulation by fishes of higher trophic levels and by men who are the final link of the food chain. (author)

Application of tracer techniques in studies of sediment transport in Vietnam

International Nuclear Information System (INIS)

Hai, P.S.; Quang, N.H.; Xuan, N.M.; Chuong, P.N.; Hien, P.Z.

1997-01-01

As a consequence of intensive erosion processes typical of the humid tropical one, as well as of human activities destroying tropical forests, grasslands and protective mangrove swamps, etc, most navigable estuaries in Vietnam suffer seriously from sedimentation. In order to maintain the necessary depth for the 7.000 ton vessels entering and leaving ports, a large amount of money is spent annually on dredging operation. A lot of hydraulic and sedimentary surveys were carried out in the past by different groups of researchers. However, owing to the complexity of sediment processes in estuarine areas under the hydrometeorological conditions typical of the southwest Pacific, the use of just any modelling approach is not suitable. In many cases, the conclusions inferred from mathematical models have been the controversial matter. The tracer techniques, which have been employed in the country since 1991, have provided a very efficient tool to obtain a dynamic idea of sediment transport. Many investigations of bedload transport using Sc-46 labelled glass and Ir-192 glass as radioactive tracers were carried out from 1992 to 1996 at Haiphong harbour area. Bedload transport rates under effect of northeast monsoon and southeast monsoon at 5 zones located on both sides of the navigation channel were estimated. In bedload transport studies, apart from conventional methods for assessment of transport thickness, a new method using the ratio of photoelectric peak to Compton region of spectra acquired directly on the sea bed was put forward and applied. The influence of dredging materials at two dumping sites under different tidal phases on in fill rate in the access channel was assessed by radioactive tracers. The qualitative and quantitative information on sediment transport at some experimental sites given by tracers was used by modelling specialists who have undertaken hydraulic and sedimentary surveys in this region

A leak-detection instrument for long buried pipelines based on radioactive tracer measurements

International Nuclear Information System (INIS)

Lu Qingqian; Zhou Shuxuan; Tang Yonghua; Sun Xiaolei; Hu Xusheng; Li Deyi; Yin Liqiang

1987-01-01

The instrument introduced provides a means for leak detection of long buried pipelines based on the radioactive tracer technique. The principle, block diagram and performances for the instrument are described. The leak-detecting method and the determination of some related parameters are also presented. Leak-detection sensitivity of the instrument is 185 kBq (5 μCi). Accuracy for leak localization is within 2.5 m (per km). It is suitable for the buried light oil (gasoline, kerosene, diesel oil) and industrial water pipelines with a diameter of 15 or 20 cm. The detection length for a single operation reaches up to 50 km

A study of the behavior of a cathode film formed in chromium plating with radioactive tracers

International Nuclear Information System (INIS)

Yoshida, Katsuyoshi; Suzuki, Akihira; Doi, Kazuyuki; Arai, Katsutoshi

1979-01-01

The behavior and composition of a cathode film formed on a steel cathode during chromium plating were studied with radioactive tracers. A special cell with a rapid washing compartment was used for preventing the cathode film from dissolving in electrolyte after plating. The cathode film was composed of two layers. The outer layer facing to the electrolyte had a loose structure and contained more sulfuric anions than the inner layer, for sulfuric acid probably concentrated in the outer layer. This outer layer is called L-film in this paper. The L-film was easily dissolved in the electrolyte solution. The inner layer (called C-film, compact film) was stable against electrolytes and contained less anions than that of L-film. The C-film had a thickness equivalent to 5 mg/m 2 and the concentration of anions unaffected by the composition of electrolytes. The C-film was not reduced to metallic chromium, but it remained in the cathode film during and after plating. This suggests that chromic acid in the cathode film is not reduced to metallic chromium, that metallic chromium is deposited from chromium complexes reaching the cathode surface through the cathode film, and that the complexes do not play a role on the construction of the cathode film. (author)

Plan for radionuclide tracer studies of the residence time distribution in the Wilsonville dissolver and preheater

International Nuclear Information System (INIS)

Jolley, R.L.; Begovich, J.M.; Brashear, H.R.

1983-12-01

Stimulus-response measurements using radiotracers to measure residence time distribution (RTD) and hydrodynamic parameters for the preheaters and dissolvers at the Ft. Lewis Solvent Refined Coal (SRC) and the Exxon Donor Solvent (EDS) coal conversion pilot plants are reviewed. A plan is also presented for a series of radioactive tracer studies proposed for the Advanced Coal Liquefaction Facility at Wilsonville, Alabama, to measure the RTD for the preheater and dissolvers in the SRC-I mode. The tracer for the gas phase will be 133 Xe, and 198 Au (on carbonized resin or as an aqueous colloidal suspension) will be used as the slurry tracer. Four experimental phases are recommended for the RTD tracer studies: (1) preheater; (2) dissolver with 100% takeoff; (3) dissolver with 100% takeoff and solids withdrawal; and (4) dissolver with 50% takeoff. Eighteen gas-tracer and 22 liquid-tracer injections are projected to accomplish the four experimental phases. Two to four tracer injections are projected for preliminary tests to ensure the capability of safe injection of the radiotracers and the collection of statistically significant data. A complete projected cost and time schedule is provided, including procurement of necessary components, preparation of the radiotracers, assembly and testing of tracer injection apparatus and detection systems, onsite work and tracer injections, laboratory experimentation, data analysis, and report writing

Accelerated physical modelling of radioactive waste migration in soil

International Nuclear Information System (INIS)

Zimmie, T.F.; De, A.; Mahmud, M.B.

1994-01-01

A 100 g-tonne geotechnical centrifuge was used to study the long-term migration of a contaminant and radioactive tracer through a saturated soil medium. The use of the centrifuge simulates the acceleration of travel time in the prototype, which is N times larger than the model, by N 2 , where N is the desired g level. For a 5 h run at 60 g, the test modelled a migration time of about 2 years for a prototype 60 times larger than the small-scale model tested. Iodine 131, used as the tracer, was injected onto the surface of the soil, and was allowed to migrate with a constant head of water through the saturated soil. End window Geiger-Mueller (G-M) tubes were used to measure the count rate of the radioactive tracer flowing through the soil. The time from the peak response of one G-M tube to the other denotes the travel time between the two points in the flow domain. The results obtained using the radioactive tracer are in good agreement with the test performed on the same model setup using potassium permanganate as tracer and with numerical flow net modelling. Radioactive tracers can be useful in the study of nonradioactive contaminants as well, offering a nonintrusive (nondestructive) method of measuring contaminant migration. (author). 18 refs., 1 tab., 7 figs

Evaluation of radiation protection in the use of radioactive tracers in the oil industry; Avaliação da proteção radiológica no uso de traçadores radioativos na indústria de petróleo

Energy Technology Data Exchange (ETDEWEB)

Oliveira, F.L.; Silva, F.C.A. da, E-mail: dasilva@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

Radioactive tracers have been widely used in the industry to optimize processes, improve product quality, save energy and reduce pollution. The petroleum industry uses sources for radioactive tracers in solid, liquid and gaseous forms to investigate or track the movement of other materials into pipes of inaccessible lines, such as, {sup 3}H, {sup 82}Br, {sup 131}I, {sup 85}Kr, {sup 41}Ar, {sup 14}C, {sup 24}Na, {sup 192}Ir , etc. The work presents the application of radioactive tracers in the area of oil and gas industry and carries out an evaluation of the radiological risk, the doses of radiation, the specific radiological protection procedures, safety and radiological emergency to be followed. It was observed that radiological risks in the use of radioactive tracers involve three aspects: external dose, external contamination and internal contamination. Most of the time the risk of radiation related to the external dose is very low because unsealed radioactive sources have low activity and exposure times are very low during handling. External and internal contaminations appear due to the use of open sources that allow direct contact and even inhalation or ingestion of radioactive material. It was identified that there is no specific Brazilian regulation for radiation protection in radioactive tracers, and the recommendations of the International Atomic Energy Agency - IAEA should be used.

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)

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)

Dynamic study of an anaerobic reactor in pilot plant scale using radioactive tracer

International Nuclear Information System (INIS)

Pinto, A.M.F.; Moreira, R.M.; Chernicharo, C.A.L.

1995-01-01

The use of flow traces is a common practice in hydrodynamic studies. However chemical tracers have some shortcomings, such as the need of sampling, analysis and possible interferences with the delicate biological processes taking place within the reactor. Thus a radiotracer, Br 82 has been chosen for this purpose. The advantages of this radioisotope are its energetic gamma emission which can be easily detected outside the reactor walls, its solubility and lack of adsorption, besides having a convenient half-life and being easily produced is small nuclear reactors. The tracer responses to instantaneous injections at the reactor entrance were used to determine the resistance time and the mixing patterns of the reactors. The normalized residence time distributions were fitted to mathematical models by a least-squares subroutine. The axial dispersion model and the tanks-in-series model have been used, thus allowing the determination of the dispersion coefficient and the Peclet Number. (author). 5 refs, 4 figs, 1 tab

Interest of radioactive tracers in fruit cultivation research

International Nuclear Information System (INIS)

Ferauge, M.T.; Dreze, Ph.

1976-01-01

The authors report some results related to the use of tracer techniques applied to nutrition and physiological diseases of fruit trees. Penetration and fate of several mineral and organic elements either by root system or by aerial parts of the trees are studied. (J.C.)

Evaporation rate in containers used for storing radioactive tracer solutions

International Nuclear Information System (INIS)

Gascon, J.L.

2002-01-01

In radiochemical analysis, the storage of a tracer solution is an important issue to bear in mind. The evaporation of the tracer solution depends on the type of container used for storing. Evaporation rate in four kinds of containers, i.e., flame-sealed glass ampoule, sealed glass flask, flame-sealed polyethylene ampoule and screw glass vial was studied. It is concluded that the evaporation rate depends on the system of closing. (author)

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.)

Application of isotope tracer technique on the study of the filling and release behavior of carbon nanotubes

International Nuclear Information System (INIS)

Wu Shengwei; Guo Jinxue; Li Yan; Li Yulan; Li Wenxin; Liu Shiyuan

2004-01-01

The behaviors of washing and release of 110 Ag m -AgNO 3 from carbon nanotubes (CNTs), following soak of opened CNTs in 110 Ag m -AgNO 3 solutions are investigated with the isotope tracer technique. The filled CNTs samples are characterized by HREM, SEM, XRD and EDS. The amount of filled materials is also estimated by the isotope tracer technique. It shows that there are silver materials filled in the CNTs and would not release from the cavities. The results indicate that radioactive tracer is an effective and powerful technique to be applied into study of filling and release behaviors of CNTs as well as estimating the amount of filled materials. (authors)

Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

International Nuclear Information System (INIS)

Crossley, D.A. Jr.

1979-01-01

Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one

Radioactive tracer studies of soil and litter arthropod food chains. Progress report, November 1, 1978-October 31, 1979

Energy Technology Data Exchange (ETDEWEB)

Crossley, Jr, D A

1979-07-15

Research on soil and litter arthropod food chains, concerning measurement of nutrient flow using radioisotope techniques and investigations of the role of soil arthropods as regulators of the ecosystem-level processes of decomposition and mineralization of nutrients is described. Laboratory measurements of radiotracer turnover by predaceous macroarthropods are reported, as well as the status of research with microarthropod turnover of radioactive tracers. Implications of results are evaluated in context of current understanding of nutrient flows along arthropod food chains. The interactions of soil fauna and mycorrhizal fungi are also under investigation. Field work has been completed on granitic outcrop projects, and a synthesis of results is summarized. Input-output budgets revealed that granitic outcrop island ecosystems are essentially in balance as regards nutrient flows. The ecosystems showed a strong resistance component of stability, as opposed to resilience, following an applied chemical perturbation and a natural one (drought).

Environmental radionuclides tracers and timers of terrestrial processes

CERN Document Server

Froehlich, Klaus

2009-01-01

The book presents a state-of-the-art summary of knowledge on the use of radionuclides to study processes and systems in the continental part of the Earth's environment. It is conceived as a companion to the two volumes of this series, which deal with isotopes as tracers in the marine environment (Livingston, Marine Radioactivity) and with the radioecology of natural and man-made terrestrial systems (Shaw, Radioactivity in Terrestrial Ecosystems). Although the book focuses on natural and anthropogenic radionuclides (radioactive isotopes), it also refers to stable environmental isotopes, which i

Survey on industrial applications of radioactive tracers

International Nuclear Information System (INIS)

Kim, Jae Rok; Yoo, Young Soo; Lee, Jong Doo; Awh, Ok Doo; Kim, Jun Hyung

1986-12-01

Current status and future feasibilities of industrial tracer applications in the Republic of Korea have been surveyed. Microleak detection using Krypton-85 in eight electronics industrial companies, and efficiency tests of steam generators in four nuclear power plants using Sodium-24 are the principal applications in Korea. Future applications are expected for mercury inventory in one soda industrial company, and alkali movement studies in two cement industrial companies. Korean industries expressed deep interest in leak detection in underground pipelines, abrasion/corrosion studies, mixing rate and residence time measurements. (Author)

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)

Mineral imbalances in farm animals and their study and diagnosis with isotopic tracers

International Nuclear Information System (INIS)

Underwood, E.J.

1976-01-01

Twenty-two mineral elements are known to be essential for animal life. These are calcium, phosphorus, sulphur, potassium, sodium, chlorine, magnesium, iron, iodine, copper, manganese, zinc, cobalt, molybdenum, selenium, chromium, tin, vanadium, fluorine, silicon, nickel and arsenic. Naturally occurring and man-made dietary imbalances of many of these elements and their interactions with other minerals are described and their functions and requirements by farm animals are outlined. The nature and importance of metabolic interactions among the mineral elements are discussed and the important concept stressed that there is no single minimum requirement or safe tolerance of a particular mineral, but a series of such minimum requirements and safe tolerances depending on the extent to which other minerals with which it interacts is present or absent from the diet. Radioactive tracer elements are shown to be of great value in the determination of mineral nutrient availability to the animal and for following mineral metabolic movements in the body. They are also shown to have considerable potential for the diagnosis of mineral imbalances. Various in vivo and in vitro techniques involving both radioactive and stable tracers developed for the early diagnosis of mineral deficiencies are described and the strengths and weaknesses of such techniques, in comparison with standard biochemical tests, are discussed. The need for further critical studies with isotopic tracers in the detection and diagnosis of mineral imbalances is emphasized. The main types of biochemical criteria used in the diagnosis of mineral deficiencies and excesses are given, with appropriate examples of their use. (author)

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.)

Application of radioactivity to subterranean hydraulic engineering (1961)

International Nuclear Information System (INIS)

Hours, R.

1961-01-01

The search for radioactive tracers for water capable of percolating through permeable grounds without significant absorption has led to the choosing of two isotopes, bromine 82 (half-life 36 hours) and iodine (half-life 8 days), both γ emitters; various combinations of other γ emitters with longer half-lives have been tried but with only partial success. The recent progress in the dosage of tritium should make it possible to widen the field of application of this tracer which is unique in its kind. Being detectable at concentrations of 10 -6 to 10 -8 curies per cubic meter, the radioactive tracers are suitable for all the usual applications of conventional tracers; furthermore, some original techniques have been devised for measurements of flow, of reservoir capacity, of porosity and of permeability. Techniques based on the absorption and scattering of γ-rays have also been developed for the measurement of the density, the humidity and the porosity of soils, and also for their analysis. Up to the present, radioactivity has been mainly applied to the study of oil-bearing formations. Furthermore, the study of the distribution of natural of thermonuclear tritium has contributed greatly to the study of the hydrological cycle. (author) [fr

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)

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.

Circulation of the medullary cerebrospinal fluid. Comparative study of various tracers

International Nuclear Information System (INIS)

Bok, B.; Thebault, B.; Cavailloles, F.; Aboulker, J.

Gammamyelography is used to study the circulation of the cerebrospinal fluid in the perimedullary sub-arachoid spaces. Many radioactive preparations have been proposed for this examination which is designed to show up all dynamic perturbations of the CSF flux. Of the criteria governing the choice of tracer some importance given has been to the molecular diffusion constant of the preparation, iodinated albumine seeming the most suitable in this respect. An attempt was made to estimate the influence of molecular weight on the tracer kinetics by comparing three preparations injected simultaneously: indium 111-labelled siderophilline of M.W. above 100,000; iodine 131-labelled human serum albumine of MW around 70,000; sup(99m)Tc-labelled DTPA, a chelate of low molecular weight. The results showed no detectable influence of the molecular weight of these preparations on their intraspinal kinetics in the time taken for the examination. In practice this work justifies the use of the preparation most convenient and least harmful from the dosimetric viewpoint for the isotope and from the antigenic toxicological viewpoint for the tracer, which means that the replacement of iodinated albumine by indium-111 DTPA for example should be possible at least at the medullary level [fr

Test determination with tritium as a radioactive tracer of the residence time distribution in the stability pool for Cabrero sewage

International Nuclear Information System (INIS)

Diaz, Francisco; Duran, Oscar; Henriquez, Pedro; Vega, Pedro; Padilla, Liliana; Gonzalez, David; Garcia Agudo, Edmundo

2000-01-01

This work was prepared by the Chilean and International Atomic Energy Agencies and covers the hydrodynamic functioning of sewage stability pools using tracers. The plant selected in the city of Cabrero, 500 km. south of Santiago, and is a rectangular facultative pool with a surface area of 7100 m 2 and a maximum volume of 12,327 m2 that receives an average flow of 20 l/s, serving a population of 7000 individuals. The work aims to characterize the runoff from the flow that enters the pool, using a radioactive tracer test, where the incoming water is marked, and its out-coming passage is determined, to establish the residence time distribution. Tritium was selected in the form of tritiated water as a tracer that is precisely emptied into the water flow from the distribution ravine at the lake entrance. Samples are taken at the outflow to determine the concentration of tritium after distillation, simultaneously measuring the flow, to be analyzed in a liquid flicker counter. An average test time of 5.3 days was obtained and an analysis of the residence time distribution for the tracer shows that it leaves quickly and indicates bad flow distribution in the lake with a major short circuit and probable dead zones

The use of tracer techniques in the study of soil water flows and contaminant transport

International Nuclear Information System (INIS)

Reeves, A.D.; Beven, K.J.

1990-04-01

This report reviews the use of different types of tracers in the characterisation of soil water flows and the implications of tracer studies for modelling contaminant transport. The tracers considered are a number of different anions, stable isotopes, radioactive tracers, organic dyes, fluorocarbons, gases, solid particles and water temperature. The theoretical basis for modelling the results of tracer experiments in terms of the traditional convective-dispersion equation (CDE) is outlined. A number of alternative modelling strategies are reviewed: the mobile/immobile water extension of the CDE; the Jury Transfer Function Model (TFM); the Aggregated Mixing Zone (AMZ) model and Random Particle Tracking models. The first will form the basis of the Systeme Hydrologique Europeen (SHE) contaminant transport component. The Jury and AMZ models are both linear models and are consequently limited to applications in which the flows may be considered to be quasi-steady or repeatable. Random particle tracking models have the advantage of both flexibility and applicability to transient and spatially variable flow domains. A random particle model is being implemented on a transputer workstation at Lancaster and will be used to explore the effect of sub-grid scale complexities on effective grid-scale parameter values for distributed models such as SHE. (author)

Radioactivity

International Nuclear Information System (INIS)

2002-01-01

This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

Management of radioactive wastes

International Nuclear Information System (INIS)

Hendee, W.R.

1984-01-01

The disposal of radioactive wastes is perhaps the most controversial and least understood aspect of the use of nuclear materials in generating electrical power, the investigation of biochemical processes through tracer kinetics, and the diagnosis and treatment of disease. In the siting of nuclear power facilities, the disposal of radioactive wastes is invariably posed as the ultimate unanswerable question. In the fall of 1979, biochemical and physiologic research employing radioactive tracers was threatened with a slowdown resulting from temporary closure of sites for disposal of low-level radioactive wastes (LLW). Radioactive pharmaceuticals used extensively for diagnosis and treatment of human disease have increased dramatically in price, partly as a result of the escalating cost of disposing of radioactive wastes created during production of the labeled pharmaceuticals. These problems have resulted in identification of the disposal of LLW as the most pressing issue in the entire scheme of management of hazardous wastes. How this issue as well as the separate issue of disposal of high-level radioactive wastes (HLW) are being addressed at both national and state levels is the subject of this chapter

Development of a data acquisition system in form of an apparatus which is specially designed for the study of the cerebral metabolism employing radioactive tracers

International Nuclear Information System (INIS)

Ponchon, J.

1988-03-01

The subject of this thesis is the development of a data acquisition system in form of an apparatus which is specially designed for the study of cerebral metabolism employing radioactive tracers. Currently, the test is based on the continuous inhalation of gas identified with oxygen 15. After an inhalation period of 6 to 8 minutes the local brain radioactivity attains an equilibrium which corresponds to the parameters of brain metabolism. The constant measurement of the radioactivity facilitates the monitoring of the evolution of these parameters. The apparatus consists of an assemby of lead collimators in which are lodged 26 gamma ray detectors (INa probes), each one of which scans a particular brain region. For ease of use and the provision of numerous possibilities, each detector has been assigned a multichannel pulse height analyser which has been developed by ourselves in order to correspond to and to comply with the demands of our tests. They are equipped with a device which automatically corrects for dead time thereby permitting the analysis of random impulses of a rate greater than 50.000 per second with a loss of less than 1%. The multichannel analysers are connected to a central computer which by means of suitably adapted software allows the calibration of different channel of measurement, controls, the choice of the zone of interest to be integrated and the presentation of integrated results in form of graphs [fr

Measurement of flow and direction of ground water by radioactive tracers: hydrological evaluation of a waste disposal site at 'Instituto de Pesquisas Energeticas e Nucleares (IPEN)'

International Nuclear Information System (INIS)

Chandra, U.; Aoki, P.E.; Ramos e Silva, J.A.; Castagnet, A.C.G.

1981-05-01

The method of determining flow and drection of ground water by using radioactive tracers in ground water borings is described. Various parameters controlling the measurements are discussed in detail. Application of the method in studying a variety of geohydrological problems, in view of the hydrological evaluation of the waste disposal site at IPEN, is indicated. Comparison of the method with conventional pumping tests is made. (I.C.R.) [pt

Double tracer experiments to investigate models for the calculation of gamma doses from a radioactive cloud

International Nuclear Information System (INIS)

Nielsen, S.P.; Gryning, S.E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

1984-01-01

The paper presents work from a series of atmospheric dispersion experiments in May 1981 at the Ringhals nuclear power plant in Sweden. The aim of the project was to obtain short-term observations of concentrations and gamma-ray exposures from stack effluents and to compare these results with corresponding values calculated from computer models. Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released from a 110-m stack and detected at ground level downwind at distances of 3-4 km. Calculations were made with two Gaussian plume models: PLUCON developed at Riso National Laboratory and UNIDOSE developed at Studsvik Energiteknik AB. (orig.)

Calibration of the 46Sc sand tracer detector and it's application

International Nuclear Information System (INIS)

Li Zhangsu; Du Xiaoyun

1993-01-01

The authors describe the process and result for the calibration of radioactive 46 Sc detector in details. The calibration was carried out under the hydrological conditions similar to the field test. The relation between the intensity of the scattered γ-rays and the various water depths was studied by using a 46 Sc plane source. The purpose of calibration of the detector with the plane source is to determine both the detector sensitivity factor and the γ-ray absorption coefficient for san/water mixture in order to calculate the thickness of the mobile water layer by means of the count rate balance method. The relation curve between the various thicknesses of the mobile layers and count rates was studied in detailed in details by using a slab source and the uniformly mixed layers with 46 Sc glass. The curve is used as the calibration curve for determining the recovery of tracking radioactive tracer in situ. The recovery of tracer shows whether the field tracer data can be used to calculate the transport sediment rate or the in fill rate of sediment

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.

A study on the piston ring wear in automotive engine Seat 1500 CA by means of radioactive tracer technique; Estudio del desgaste de segmentos en motor Seat 1500 CA mediante trazadores radiactivos

Energy Technology Data Exchange (ETDEWEB)

Val Cob, M del; Chul, Y; Fuentes Figuera de Vargas, J.

1971-07-01

The iron side wear in the chromium-plated top compression ring has been a matter of interest for the engine makers and it has been required by them to investigate the wear characteristics of the chromium-plated piston ring. Meanwhile, Bureau of Nuclear Energy in Spain (Junta de Energia Nuclear) and Seat Car Manufacturing Company (Sociedad Espanola de Automoviles de Turismo) agreed to study the wear characteristics of chromium-plated piston ring of type CA gasoline engine for Seat 1500 car by means of radioactive tracer technique. (Author) 9 refs.

Leakproof control of technological installations and underground pipelines using radioactive tracers as a contribution to the protection of the natural environment

International Nuclear Information System (INIS)

Kras, J.; Walis, L.; Myczkowski, S.; Panczyk, E.

2004-01-01

The radioisotope method of leakproof control and leak localization has the following advantages: simplicity, short time of duration of experiment, low cost, short time need for adaptation of the object for the control, high sensitivity of measurements. Owing the application of the isotope technique is possible to carry out the expertise at low pressure, which permits to avoid strength effort of the construction materials. Through the radioisotope method is not a strength test it is complementary to pressure test (hydraulic or pneumatic). It should be noted that the hydraulic test cannot be applied to some technological objects despite the need of their leakproof control. The presentation deals with principles of application of the radioactive tracer - methyl bromide with Br-82, its preparation and ways of injecting the tracer and carrying out radiometric measurements in dependence on the kind of the object examined. The radioisotope tracer method for leakproof control of technological objects and underground pipelines as well as the apparatus used for this control have been developed in the Institute of Nuclear Chemistry and Technology and have been routinely used. (author)

Use of radioactive tracers in chemical reactions. the displacement of zinc-nickel complexes with quantitative determination of nickel

International Nuclear Information System (INIS)

Mazzilli, B.; Saiki, M.

1983-01-01

The present paper presents a method for the determination of small quantities of nickel radioactive tracers. 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 tetrachloride 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 0.1 μg/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 is also investigated and an attempt is made in order to eliminate them by using masking agents or by means of a previous separation between nickel and other interfering metals. (Author) [pt

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)

Radioactive tracers and the cracking modelings

International Nuclear Information System (INIS)

Bettens, B.

1982-01-01

The use of tracers (3H and 14 C) labelled in specific positions is an intensive contribution to the understanding and the revealing of the very often complex cracking modeling. The pyrolytic decay of the phenol and the cresols, of the aniline, of the phenantrene and its hydrogenated derived products were investigated and are presented as examples. The decay mechanisms give a theoretical knowledge of the thermal cracking and allow to handle the results on an industrial scale. (AF)

Radiometric report for a blast furnace tracing with radioactive isotopes

International Nuclear Information System (INIS)

Tanase, G.; Tanase, M.

1995-01-01

One of the methods to monitor refractory wall of blast furnace is its tracing with radioactive isotopes. The tracer isotope can be detected by two ways: the external dosimetric measurement at the armour of the blast furnace and/or the radiometric measurement of the iron sample charge by charge. Any change in radiometric situation of tracer radioisotope is recorded in a radiometric report. This paper presents an original concept of radiometric report based upon PARADOX and CORELDRAW soft kits. Their advantage are: quick and easy changes, easy recording of current radioactivity of tracer isotope, short history of changes, visual mapping of the tracer isotope and others. In this way we monitored 6 blast furnaces and more than 180 radioactive sources

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)

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)

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)

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)

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

Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas

International Nuclear Information System (INIS)

Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. . e mail: efrp@nuclear.inin.mx

2008-01-01

In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO 3 ) 3 6H 2 O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

Bottom sediment transport by radioactive tracer techniques off a stretch of the southern coast from Sao Paulo State - Brazil; Trasnporte do sedimento de fundo por tecnicas de tracadores radioativos ao largo de trecho da costa sul do Estado de Sao Paulo - Brasil

Energy Technology Data Exchange (ETDEWEB)

Bomtempo, V.L. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)

1995-12-31

This paper presents the methodology and results obtained with radioactive tracer techniques as applied to study sea-bottom sediments movements off a stretch of the southern coast of Sao Paulo State, Brazil, namely Praia do Una. Three injections of ground glass containing Iridium-192 were made and the behaviour of this material was tracked by special detection techniques, as it was acted upon by hydrodynamic agents, in two distinct periods of the year of 1982 (summer and winter). Measurement of hydrodynamic parameters was conducted simultaneously with tracer experiments. From the experiments with radioactive tracers, combined with other conventional studies, qualitative and quantitative conclusions could be drawn, as follows: waves are the prevailing agents in moving bottom sediments; during summer time, onshore and alongshore transport can be identified; during winter time, offshore and alongshore transport are present; for summer conditions, Massif transport rate was estimated to be 150 kg m{sup -1} day {sup -1}. (author). 2 refs, 3 figs.

Earth mechanisms (fluid and solid), life mechanisms and stable isotope tracers. Isotopes and biology, a great project

International Nuclear Information System (INIS)

Fromageot, P.

1997-01-01

Historical and recent review of the development and use of radioactive isotopes for biological studies in France: study of the intermediate metabolism with 14 C tracers in organic molecules; study and biosynthesis of macromolecules (DNA, RNA and polynucleotides) through the use of marked nucleotides; tracer proteins for use in NMR and protein engineering, use of tritium for the study of hormonal regulation

Tracer-level radioactive pilot-scale test of in situ vitrification technology for the stabilization of contaminated soil sites at ORNL

International Nuclear Information System (INIS)

Jacobs, G.K.; Spalding, B.P.

1991-11-01

This plan summarizes the activities to be performed during FY 1990 and FY 1991 for the tracer-level radioactive pilot-scale in situ vitrification (ISV) test. This test is the second step in evaluating ISV as a remedial action for the pits and trenches at Oak Ridge National Laboratory (ORNL). A previous test used nonradioactive tracers for cesium and strontium. This new test will again use a one-half-scale model of trench 7 and the pilot-scale ISV equipment of Pacific Northwest Laboratory (PNL). A small and precisely known amount of waste from a liquid waste disposal pit will be used for the test. An actually contaminated waste site cannot be used for this test because of the necessity to use an exactly known inventory of radionuclides so that a precise measurement of the volatilization of various constituents to the off-gas can be determined

Determination of Columbia River flow times from Pasco, Washington using radioactive tracers introduced by the Hanford reactors

Science.gov (United States)

Nelson, Jack L.; Perkins, R.W.; Haushild, W.L.

1966-01-01

Radioactive tracers introduced into the Columbia River in cooling water from the Hanford reactors were used to measure flow times downstream from Pasco, Washington, as far as Astoria, Oregon. The use of two tracer methods was investigated. One method used the decay of a steady release of Na24 (15-hour half-life) to determine flow times to various downstream locations, and flow times were also determined from the time required for peak concentration of instantaneous releases of I131 (8-day half-life) to reach these locations. Flow times determined from the simultaneous use of the two methods agreed closely. The measured flow times for the 224 miles from Pasco to Vancouver, Washington, ranged from 14.6 to 3.6 days, respectively, for discharges of 108,000 and 630,000 ft3/sec at Vancouver, Washington. A graphic relation for estimating flow times at discharges other than those measured and for several locations between Pasco and Vancouver was prepared from the data of tests made at four river discharges. Some limited data are also presented on the characteristics of dispersion of I131 in the Columbia River.

Impact of Radioactivity on the Life Sciences

International Nuclear Information System (INIS)

Broda, E.

1968-01-01

This document is a reprint from ‘Maria Sklodowska-Curie: Centenary Lectures’, published by the IAEA in 1968. It is about tracer methods and application of radioactive tracer methods to living systems. (nowak)

Radioactive tracer applications in the study of flow reactors. 4

International Nuclear Information System (INIS)

Thyn, J.; Hovorka, J.

1975-01-01

Response curves of gas streaming through the jet fluidized bed of a granular material in a rotary-jet pilot reactor were measured for a number of gas flow rates. A mathematical model of the gas residence time distribution was designed. Good agreement of the mathematical model with the experiments permits determining the ratio of streaming through the fluidized bed in form of bubbles of a different size. The measured values were evaluated as the distribution density of the gas residence time (age) at the outlet, the distribution function of the internal gas age in the device, and the so-called intensity function. The gas was labelled by a rapid injection of the radioactive 85 Kr and the response was studied by specially connected Geiger-Mueller counters placed inside the device, immediately above the granular material bed. (author)

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)

Investigation on the loss of trace elements in biological materials in different drying and ashing procedures by using radioactive tracers: Pt. 1

International Nuclear Information System (INIS)

Wang Yongxian; Qin Junfa; Ji Qianmei; Wu Shimin; Wang Xuepeng; Zhang Yuanxun

1985-01-01

By using radioactive tracers it is found that freezing dry is safe for Zn, Mo, Cd and Se in all matrices studied. Oven dry is also safe except for Se in hair. The oxygen plasma ashing does not cause any loss of Zn, Mo and Cd. Different degrees of loss were observed in oven ashing with exception of Zn and Mo in hair and shallot. It is obvious that the loss rate of the trace elements depends on their chemical forms present in the matrices. The retention of the four elements studied on the wall of quartz container can be neglected after oxygen plasma ashing. But Zn, Cd and Mo were retended in various degrees after oven ashing

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

Radioactive tracer profiling system and apparatus

International Nuclear Information System (INIS)

Wiley, R.; Veach, L.

1977-01-01

A radioactive charge is ejected into the borehole and a subsurface unit including a radiation detector is moved upwardly through this charge a number of times. The total radiation count as the unit moves up through the charge is obtained by integrating the output of the radiation detector during the period when the counter output exceeds the background radiation. The integrated count is displayed on a digital display unit. Compensation is provided for background radiation within the borehole. Also correction is made for the dead time of the radiation detector so that an accurate indication of the total amount of radioactivity remaining in the borehole during successive runs is obtained. 22 claims, 6 figures

Prospect of radon as a tracer in studying of landslide forecast

International Nuclear Information System (INIS)

Zhang Huifeng; Ding Dexin

2004-01-01

Radon, as a chemical element of radioactivity, is widely used in the fields of earth-quake monitoring, prospecting mine and exploring resource. This paper discussed the theory of radon's separating out from the soil and the theory and means of surveying radon. It also relates the radon anomaly in the measuring process of soil radon, caused by the interferring of the environmental factors in measurement results. It further clarifies the wilde application of radon as a tracer in landslide forecast. (authors)

Radiation safety and regulatory aspects of tritium used as tracer in oil exploration

International Nuclear Information System (INIS)

Agarwal, S.P.

2005-01-01

Radiotracers have been used to trace the movement of a particular fluid at a well since the turn of the century. It is recognized that a properly designed and implemented radioactive tracing program can highly be cost effective in tracking the movement of oil field waters. Radioactive tracer results provide a practical link between macroscopic field interpretation from seismic and geological studies and localized core production wells

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

Development and evaluation of a tracer-injection hydrothermal technique for studies of waste package interactions

International Nuclear Information System (INIS)

Jones, T.E.; Coles, D.G.; Britton, R.C.; Burnell, J.R.

1986-11-01

A tracer-injection system has been developed for use in characterizing reactions of waste package materials under hydrothermal conditions. High-pressure liquid chromatographic instrumentation has been coupled with Dickson-type rocking autoclaves to allow injection of selected components into the hydrothermal fluid while maintaining run temperature and pressure. Hydrothermal experiments conducted using this system included the interactions of depleted uranium oxide and Zircaloy-4 metal alloy discs with trace levels of 99 Tc and non-radioactive Cs and I in a simulated groundwater matrix. After waste-package components and simulated waste forms were pre-conditioned in the autoclave systems (usually 4 to 6 weeks), known quantities of tracer-doped fluids were injected into the autoclaves' gold reaction bag at run conditions. Time-sequenced sampling of the hydrothermal fluid providing kinetic data on the reactions of tracers with waste package materials. The injection system facilitates the design of experiments that will better define ''steady-state'' fluid compositions in hydrothermal reactions. The injection system will also allow for the formation of tracer-bearing solid phases in detectable quantities

Radioactivity; La radioactivite

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

Predictors of sentinel lymph node metastases in breast cancer-radioactivity and Ki-67.

Science.gov (United States)

Thangarajah, Fabinshy; Malter, Wolfram; Hamacher, Stefanie; Schmidt, Matthias; Krämer, Stefan; Mallmann, Peter; Kirn, Verena

2016-12-01

Since the introduction of the sentinel node technique for breast cancer in the 1990s patient's morbidity was reduced. Tracer uptake is known to be dependent from lymph node integrity and activity of macrophages. The aim of this study was to assess whether radioactivity of the tracer can predict sentinel lymph node metastases. Furthermore, a potential association with Ki-67 index was examined. Non-invasive prediction of lymph node metastases could lead to a further decrease of morbidity. We retrospectively analyzed patients with primary breast cancer who underwent surgery at the Department of Obstetrics and Gynecology in the University Hospital of Cologne between 2012 and 2013. Injection of radioactive tracer was done a day before surgery in the department of Nuclear Medicine. Clinical data and radioactivity of the sentinel node measured the day before and intraoperatively were abstracted from patient's files. Of 246 patients, 64 patients had at least one, five patients had two and one patient had three positive sentinel lymph nodes. Occurrence of sentinel lymph node metastases was not associated with preoperative tracer activity (p = 0,319), intraoperative tracer activity of first sentinel node (p = 0,086) or with loss of tracer activity until operation (p = 0,909). There was no correlation between preoperative Ki-67 index and occurrence of lymph node metastases (p = 0,403). In our cohort, there was no correlation between radioactivity and sentinel node metastases. Tracer uptake might not only be influenced by lymph node metastases and does not predict metastatic lymph node involvement. Copyright © 2016 Elsevier Ltd. All rights reserved.

Live controls for radioisotope tracer food chain experiments using meiofauna

International Nuclear Information System (INIS)

Montagna, P.A.

1983-01-01

Formalin poisoned samples are inadequate for measuring the amount of label to be subtracted as control values for certain food chain studies that employ radioactive tracers. In some studies, tracer is added just before incubation to label ''food'' during the feeding study. Commonly, parallel, poisoned incubations are used to distinguish between biotic and abiotic label incorporation. But, a poisoned control does not account for label that could enter a consumer via active transport, epicuticular microfloral uptake, or grazing on labeled, non-food particles. Experiments were performed to test if label uptake is greater in live non-grazing than dead organisms. Marine benthic meiofauna incoporate from 3 to 133 times more tracer when they are alive and not grazing than when they are formalin killed. These results suggest that control experiments with live animals be performed to measure all processes by which label can enter consumers in food chain experiments. (orig.)

Transdiaphragmatic transport of tracer albumin from peritoneal to pleural liquid measured in rats.

Science.gov (United States)

Lai-Fook, Stephen J; Houtz, Pamela K; Jones, Philip D

2005-12-01

In conscious Wistar-Kyoto rats, we studied the uptake of radioactive tracer (125)I-albumin into the pleural space and circulation after intraperitoneal (IP) injections with 1 or 5 ml of Ringer solution (3 g/dl albumin). Postmortem, we sampled pleural liquid, peritoneal liquid, and blood plasma 2-48 h after IP injection and measured their radioactivity and protein concentration. Tracer concentration was greater in pleural liquid than in plasma approximately 3 h after injection with both IP injection volumes. This behavior indicated transport of tracer through the diaphragm into the pleural space. A dynamic analysis of the tracer uptake with 5-ml IP injections showed that at least 50% of the total pleural flow was via the diaphragm. A similar estimate was derived from an analysis of total protein concentrations. Both estimates were based on restricted pleural capillary filtration and unrestricted transdiaphragmatic transport. The 5-ml IP injections did not change plasma protein concentration but increased pleural and peritoneal protein concentrations from control values by 22 and 30%, respectively. These changes were consistent with a small (approximately 8%) increase in capillary filtration and a small (approximately 20%) reduction in transdiaphragmatic flow from control values, consistent with the small (3%) decrease in hydration measured in diaphragm muscle. Thus the pleural uptake of tracer via the diaphragm with the IP injections occurred by the near-normal transport of liquid and protein.

Sistem Pre Kompilasi Data Tracer Studi Online Ditjen Belmawa Ristekdikti (Studi Kasus: Politeknik Harapan Bersama

Directory of Open Access Journals (Sweden)

Very Kurnia Bakti

2017-01-01

Full Text Available Tracer studi merupakan salah satu upaya yang diharapkan dapat menyediakan informasi untuk mengevaluasi hasil pendidikan di Politeknik Harapan Bersama dari kuisioner yang diberikan kepada alumni. Kegiatan tracer studi ini sudah dilaksanakan secara online, namun masih terdapat kendala pada bagian sistem yang digunakan saat ini, hal tersebut menyebabkan Politeknik Harapan Bersama tidak dapat melaporkan / mengunggah hasil tracer studi kepada Ditjen Belmawa Ristekdikti, dimana form kuisioner dan data export tracer studi yang dihasilkan berbeda dengan kebutuhan seperti yang tercantum pada surat edaran No. 313/B/SE/2016 tentang pelaksanaan tracer studi di tingkat perguruan tinggi. Mengingat pentingnya tracer studi sebagai umpan balik bagi Politeknik Harapan Bersama, maka perlu solusi untuk mengatasi kekurangan sistem ini. Dengan merubah sistem yang ada dengan sistem tracer studi yang baru merupakan solusi yang tepat dalam permasalahan ini. Sistem tracer studi yang baru mampu menghasilkan data tracer studi alumni dan pengisian form kuisioner sesuai dengan standar Ditjen Belmawa Ristekdikti yang dapat diunggah sistem tracer studi ristekdikti.

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

Elimination of nonspecific radioactivity from [76Br]bromide in PET study with [76Br]bromodeoxyuridine

International Nuclear Information System (INIS)

Li Lu; Bergstroem, Mats; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-01-01

[ 76 Br]Bromodeoxyuridine ([ 76 Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [ 76 Br]bromide. A first study assessed the potential of diuretics to eliminate [ 76 Br]bromide. [ 76 Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better 76 Br elimination than the other diuretics. In a second experiment, rats were given [ 76 Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [ 76 Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [ 76 Br]BrdU as a tracer for DNA synthesis using PET

Field measurements of tracer gas transport by barometric pumping

International Nuclear Information System (INIS)

Lagus, P.L.; McKinnis, W.B.; Hearst, J.R.; Burkhard, N.R.; Smith, C.F.

1994-01-01

Vertical gas motions induced by barometric pressure variations can carry radioactive gases out of the rubblized region produced by an underground nuclear explosion, through overburden rock, into the atmosphere. To better quantify transit time and amount of transport, field experiments were conducted at two sites on Pahute Mesa, Kapelli and Tierra, where radioactive gases had been earlier detected in surface cracks. At each site, two tracer gases were injected into the rubblized chimney 300-400 m beneath the surface and their arrival was monitored by concentration measurements in gas samples extracted from shallow collection holes. The first ''active'' tracer was driven by a large quantity of injected air; the second ''passive'' tracer was introduced with minimal gas drive to observe the natural transport by barometric pumping. Kapelli was injected in the fall of 1990, followed by Tierra in the fall of 1991. Data was collected at both sites through the summer of 1993. At both sites, no surface arrival of tracer was observed during the active phase of the experiment despite the injection of several million cubic feet of air, suggesting that cavity pressurization is likely to induce horizontal transport along high permeability layers rather than vertical transport to the surface. In contrast, the vertical pressure gradients associated with barometric pumping brought both tracers to the surface in comparable concentrations within three months at Kapelli, whereas 15 months elapsed before surface arrival at Tierra. At Kapelli, a quasisteady pumping regime was established, with tracer concentrations in effluent gases 1000 times smaller than concentrations thought to exist in the chimney. Tracer concentrations observed at Tierra were typically an order of magnitude smaller. Comparisons with theoretical calculations suggest that the gases are traveling through ∼1 millimeter vertical fractures spaced 2 to 4 meters apart. 6 refs., 18 figs., 3 tabs

Synthesis of tracers using automated radiochemistry and robotics

International Nuclear Information System (INIS)

Dannals, R.F.

1992-07-01

Synthesis of high specific activity radiotracers labeled with short-lived positron-emitting radionuclides for positron emission tomography (PET) often requires handling large initial quantities of radioactivity. High specific activities are required when preparing tracers for use in PET studies of neuroreceptors. A fully automated approach for tracer synthesis is highly desirable. This proposal involves the development of a system for the Synthesis of Tracers using Automated Radiochemistry and Robotics (STARR) for this purpose. While the long range objective of the proposed research is the development of a totally automated radiochemistry system for the production of major high specific activity 11 C-radiotracers for use in PET, the specific short range objectives are the automation of 11 C-methyl iodide ( 11 CH 3 I) production via an integrated approach using both radiochemistry modular labstations and robotics, and the extension of this automated capability to the production of several radiotracers for PET (initially, 11 C-methionine, 3-N-[ 11 C-methyl]spiperone, and [ 11 C]-carfentanil)

Leak testing of bubble-tight dampers using tracer gas techniques

Energy Technology Data Exchange (ETDEWEB)

Lagus, P.L. [Lagus Applied Technology, Inc., San Diego, CA (United States); DuBois, L.J. [Commonwealth Edison, Zion, IL (United States); Fleming, K.M. [NCS Corporation, Columbus, OH (United States)] [and others

1995-02-01

Recently tracer gas techniques have been applied to the problem of measuring the leakage across an installed bubble-tight damper. A significant advantage of using a tracer gas technique is that quantitative leakage data are obtained under actual operating differential pressure conditions. Another advantage is that leakage data can be obtained using relatively simple test setups that utilize inexpensive materials without the need to tear ducts apart, fabricate expensive blank-off plates, and install test connections. Also, a tracer gas technique can be used to provide an accurate field evaluation of the performance of installed bubble-tight dampers on a periodic basis. Actual leakage flowrates were obtained at Zion Generating Station on four installed bubble-tight dampers using a tracer gas technique. Measured leakage rates ranged from 0.01 CFM to 21 CFM. After adjustment and subsequent retesting, the 21 CFM damper leakage was reduced to a leakage of 3.8 CFM. In light of the current regulatory climate and the interest in Control Room Habitability issues, imprecise estimates of critical air boundary leakage rates--such as through bubble-tight dampers--are not acceptable. These imprecise estimates can skew radioactive dose assessments as well as chemical contaminant exposure calculations. Using a tracer gas technique, the actual leakage rate can be determined. This knowledge eliminates a significant source of uncertainty in both radioactive dose and/or chemical exposure assessments.

Influence of bovine LH tracer quality on levels of LH in GnRH-treated cows

International Nuclear Information System (INIS)

Madej, A.; Hallin, P.; Madej, M.; Seguin, B.; Edqvist, L.E.

1989-01-01

Chromatography of 125I-bovine LH (LER-1716-2 and USDA-I-1) by means of anion exchange high performance liquid chromatography (HPLC) revealed two main peaks of radioactivity regardless as to whether or not the tracer was initially purified on cellulose CF11. The content of radioactivity in the first peak tended to increase as the storage time of the bLH preparation, either before or after iodination, increased. The first peak of radioactivity after HPLC fractionation either with or without cellulose adsorption consisted of material with low binding ability to bLH antiserum (6.9% +/- 0.5 and 13.0% +/- 1.0, respectively) and high binding ability to ovine LH alpha antiserum (51.0% +/- 2.7 and 35.2% +/- 3.6, respectively). The average ratio of alpha-subunit immuno-reactivity to 125I-bLH immunoreactivity in this material was 7.4 +/- 0.1 and 2.7 +/- 0.2, respectively (P less than 0.001). Peaks in 125I-bLH radioactivity and 125I-bLH immunoreactivity had different elution times. Radioimmunoassays with tracers obtained from fractions derived from the first radioactive peak after HPLC chromatography (i.e. 125I-bLH-LER-1716-2) both with and without cellulose adsorption, yielded significantly lower mean plasma LH levels in GnRH-treated cows compared with the control tracer routinely purified only on cellulose CF11 (e.g. 5.7 vs. 8.2 micrograms/; 4.6 vs. 8.2 micrograms/l). Plasma LH levels in GnRH-treated cows were significantly (P less than 0.001) lower as measured by radioimmunoassay utilizing 125I-USDA-blH-I-1 tracers than by radioimmunoassays utilizing 125I-blH-LER-1716-2 tracers (i.e. either Y = 0.17 + 0.75X or Y = 1.18 + 0.60X)

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

Studies on the distribution of 2,4 D herbicide in soil-plant ecosystem using isotope tracer techniques

International Nuclear Information System (INIS)

Onal, G.

1986-01-01

In this study, distribution of 2,4 Diclorophenoxyacetic acid (2,4 D) herbicide in soil-plant ecosystems under greenhouse conditions were investigated by using isotope tracer techniques. For this purpose barley, wheat and oat plants were grown in two different kinds of soil taken from surrounding of Ankara and the distribution of the herbicide between soil and plants were investigated. In the research 14 C-2,40 D was used and the radioactivity was measured in a liquid scintillation counter. (author)

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

STRATEGIES FOR QUANTIFYING PET IMAGING DATA FROM TRACER STUDIES OF BRAIN RECEPTORS AND ENZYMES.

Energy Technology Data Exchange (ETDEWEB)

Logan, J.

2001-04-02

A description of some of the methods used in neuroreceptor imaging to distinguish changes in receptor availability has been presented in this chapter. It is necessary to look beyond regional uptake of the tracer since uptake generally is affected by factors other than the number of receptors for which the tracer has affinity. An exception is the infusion method producing an equilibrium state. The techniques vary in complexity some requiring arterial blood measurements of unmetabolized tracer and multiple time uptake data. Others require only a few plasma and uptake measurements and those based on a reference region require no plasma measurements. We have outlined some of the limitations of the different methods. Laruelle (1999) has pointed out that test/retest studies to which various methods can be applied are crucial in determining the optimal method for a particular study. The choice of method will also depend upon the application. In a clinical setting, methods not involving arterial blood sampling are generally preferred. In the future techniques for externally measuring arterial plasma radioactivity with only a few blood samples for metabolite correction will extend the modeling options of clinical PET. Also since parametric images can provide information beyond that of ROI analysis, improved techniques for generating such images will be important, particularly for ligands requiring more than a one-compartment model. Techniques such as the wavelet transform proposed by Turkheimer et al. (2000) may prove to be important in reducing noise and improving quantitation.

Radioactive zinc in soil-plant relationship studies

International Nuclear Information System (INIS)

Karimian, N.

1986-01-01

Zinc is one of the elements whose essentiality for plant growth and development has been proved beyond any doubt. Plant life and consequently the crop yield is impossible without zinc. The results of chemical, greenhouse, and field experiments on soils of Shiraz show that their level of available zinc for some crops is inadequate, despite the fact that the total amount of zinc in these soils may be relatively high. Obtaining the maximum yield, therefore, requires that either supplemental zinc be applied as chemical fertilizers or make the endogenous zinc more available to plants through some management practices. One of the isotopes of zinc, i.e. 65 Zn, is radioactive and has a detectable radiation which makes it suitable for tracer studies of zinc in soil, water, plant and animal. These studies help in understanding the soil plant relationships of zinc which in turn help to determine the optimum conditions of obtaining maximum yield. This paper presents and analyzes the results of some selected experiments to show different techniques of using radioactive zinc in understanding the behavior of zinc in soil and plant. Suggestions are also made of using this radioisotope in understanding the reactions of zinc in soils of Iran

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.

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

A Study Plan for Determining Recharge Rates at the Hanford Site Using Environmental Tracers

Energy Technology Data Exchange (ETDEWEB)

Murphy, E. M.; Szecsody, J. E.; Phillips, S. J.

1991-02-01

. 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. Study sites at Hanford were chosen close to micrometeorology stations on downwind transects from the operational facilities. Initial testing will be done on sites that lack perennial vegetation. Six tracer techniques (total chlortde, {sup 36}Cl, {sup 3}H, nitrate, {sup 129}I, and {sup 99}Tc) will be tested on at least one site in the Quincy sand, one site in the Warden si~ loam, and the background site, to determine which combination of tracers wortks best for a given soil type. In subsequent years, additional sites will be investigated to determine the effect of vegetation on recharge estimates and on the performance of individual tracers. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial vartability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other and sites operated by the U.S. Department of Energy as well as at low-level radioactive waste disposal sites.

In vitro studies. Contribution of radioactive marking to molecular biology development

International Nuclear Information System (INIS)

Sentenac, A.

1997-01-01

The spectacular and rapid development of molecular biology is essentially related to the utilization of marked molecules which leads to quantitative and qualitative information; the use of radioactive tracers allowed for the observation of the biosynthesis of biological polymers, and thus, for example, the formation of DNA, RNA or proteins. A historical review of the great discoveries in this field, is presented

Study on the flow state of groundwater by isotope tracer

International Nuclear Information System (INIS)

Lin Tong; Chen Jiansheng; Chen Liang

2008-01-01

Radioisotope logging technique is an effective method to evaluate groundwater movement. Moving with the water, the isotope tracer distributes differently in different flow states. According to the depth and time distribution of radioactivity, flow state of the groundwater can be determined. In this paper, different flow states, i.e. laminar flow, turbulent flow and mixing flow, are analyzed, and calculation of the flow velocity is discussed. Also, we discuss how to distinguish the laminar flow part and turbulent part in a mixing flow. If one judges the flow state incorrectly, the error of flow velocity will be huge, hence the importance of flow state analysis. Finally, some problems in the practical projects and measuring methods are concluded. (authors)

Tracer simulation using a global general circulation model: Results from a midlatitude instantaneous source experiment

International Nuclear Information System (INIS)

Mahlman, J.D.; Moxim, W.J.

1978-01-01

An 11-level general circulation model with seasonal variation is used to perform an experiment on the dispersion of passive tracers. Specially constructed time-dependent winds from this model are used as input to a separate tracer model. The methodologies employed to construct the tracer model are described.The experiment presented is the evolution of a hypothetical instantaneous source of tracer on 1 Janaury with maximum initial concentration at 65 mb, 36 0 N, 180 0 E. The tracer is assumed to have no sources or sinks in the stratosphere, but is subject to removal processes in the lower troposphere.The experimental results reveal a number of similarities to observed tracer behavior, including the average poleward-downward slope of mixing ratio isopleths, strong tracer gradients across the tropopause, intrusion of tracer into the Southern Hemisphere lower stratosphere, and the long-term interhemispheric exchange rate. The model residence times show behavior intermediate to those exhibited for particulate radioactive debris and gaseous C 14 O 2 . This suggests that caution should be employed when either radioactive debris or C 14 O 2 data are used to develop empirical models for prediction of gaseous tracers which are efficiently removed in the troposphere.In this experiment, the tracer mixing ratio and potential vorticity evolve to very high correlations. Mechanisms for this correlation are discussed. The zonal mean tracer balances exhibit complex behavior among the various transport terms. At early stages, the tracer evolution is dominated by eddy effects. Later, a very large degree of self-cancellation between mean cell and eddy effects is observed. During seasonal transitions, however, this self-cancellation diminishes markedly, leading to significant changes in the zonal mean tracer distribution. A possible theoretical explanation is presented

Case study: evaluation of clinker griding systems using radioactive tracers

International Nuclear Information System (INIS)

Sebastian, C.; Maghella, G.; Mamani, E.

2000-12-01

This work was carried out in a clinker grinding system, during operation. A small amount of La 2 O 3 was irradiated to produce the gamma emitter radioisotope Lanthanum-140. The radioactive dust of La 2 O 3 was agglomerated with rapid setting cement to obtain a radiotracer with mechanical properties similar to the ones of the clinker. The time of passage of the mill feed material, the retention time distribution in the grinding system and a radiotracer balance in the system, allow us to find the milling hold up and the efficiency of the milling system with recirculation of gross particles into the mill. The fine particles, (dust) obtained as a find product are taken into account to verify the efficiency of the system

Determination of the aerosol filters efficiency by means of the tracer techniques

International Nuclear Information System (INIS)

Hirling, J.

1978-01-01

Estimation of the nonradioactive methods of filters efficiency determination and tracer techniques are given. The methods are stated and discriptions of the instrumentation for estimation of the filters efficiency are given, in particular: methodology of production of the radioactive synthetic test-aerosols by means of the disperse and steamcondensation aerosol generators; the radio isotope method of the aerosol filters investigations; the methodology of filtartion efficiency determination. The results are given of the radioisotope investigations of filters; properties of the artificial radioactive test-aerosols; characteristics of filters, determined by the tracer techniques. Curves are given for the filtration efficiency of the viscose filtering nozzles of different density depending on the filters load. (I.T.) [ru

Extended application of radon as a natural tracer in oil reservoirs

Directory of Open Access Journals (Sweden)

Moreira R.M.

2013-05-01

Full Text Available In the 80's it was a common practice in the study of contamination by NAPL to incorporate a tracer to the medium to be studied. At that time the first applications focused on the use of 222Rn, a naturally occurring radioactive isotope as a natural tracer, appropriate for thermodynamics studies, geology and transport properties in thermal reservoirs. In 1993 the deficit of radon was used to spot and quantify the contamination by DNAPL under the surface. For the first time these studies showed that radon could be used as a partitioning tracer. A methodology that provides alternatives to quantify the oil volume stored in the porous space of oil reservoirs is under development at CDTN. The methodology here applied, widens up and adapts the knowledge acquired from the use of radon as a tracer to the studies aimed at assessing SOR. It is a postulation of this work that once the radon partition coefficient between oil and water is known, SOR will be determined considering the increased amount of radon in the water phase as compared to the amount initially existent as the reservoir is flooded with water. This paper will present a description of the apparatus used and some preliminary results of the experiments.

A novel recession rate physics methodology for space applications at CIRA by means of CIRCE radioactive beam tracers

Science.gov (United States)

De Cesare, M.; Di Leva, A.; Del Vecchio, A.; Gialanella, L.

2018-03-01

Thermal protection systems (TPSs) of spacecrafts, either for single use or reusable, experience wear by ablation and erosion, due to the high heat fluxes during a re-entry phase in the atmosphere. The determination of the wear rate is a crucial point, which is presently mainly possible in aerospace on-ground measurements by means of invasive diagnostics. The purpose of this paper is to present novel contactless, online, high-sensitivity and non-intrusive diagnostics for wear measurements based on radioactive tracers. We propose the technique for future on-ground experiments that might later be developed to perform in-flight TPSs monitoring, thus significantly increasing the safety of the aerospace vehicles. The basic ideas of the method, its sensitivity investigated by GEANT4 simulations, and the future experimental validation are outlined.

Evaluation of urban and industrial wastewater treatment plants using radioactive tracers; Otimizacao de unidades de tratamento de aguas residuais urbanas e industriais empregando-se tracadores radioativos

Energy Technology Data Exchange (ETDEWEB)

Brandao, Luis Eduardo Barreira

2001-07-01

A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as {sup 82} Br ( for the liquid phase), {sup 110m} Ag and {sup 140} La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time {gamma}, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

Determination of the self purification of streams using tracers

International Nuclear Information System (INIS)

Salviano, J.S.

1982-04-01

A methodology for the 'in situ' evaluation of the self purification of streams is discussed. It consists of the simultaneous injection of two tracers into the stream. One of the tracers is oxidized by biochemical processes. It can be either artificially supplied to the stream or a naturally present component can be used. This tracer is used for the determination of the self purification parameters. The other tracer is conservative and allows for the hydrodynamic effects. Tests have been carried out in two streams with quite different hydrodynamic and physicochemical conditions. In the first stream, with a flow-rate of about 0.9 m 3 /s, urea was used as the nonconservative tracer. In the other stream, which had a flow-rate of about 5 m 3 /s, only a radioactive tracer has been used, and the rate of biochemical oxidation has been determined from BOD measurements. Calculations have been implemented on a digital computer. In both cases it was found that the reoxygenation rate is more conveniently determined by empirical formulas. Results from both tests have been deemed realistic by comparison with similar experiments. (Author) [pt

Measurement of radioactivity in rain

International Nuclear Information System (INIS)

Eivindson, T.

1985-01-01

The report gives a description of an ion-exchange surveillance- sampler for routine measurements of radioactivity in rain, and how the measurements are performed. Using the nuclides 85 Sr, 131 I and 137 Cs as tracers, experiments have been performed to determine the distribution of radioactivity in the ion-exchange column and the effectiveness of the column as a function of elutriation rate and temperature

Synthesis of radiolabelled organic compounds for use as water tracers in oil reservoirs

International Nuclear Information System (INIS)

Eriksen, D.Oe.; Bjoernstad, V.

1999-01-01

Injection of water into oil containing strata to maintain field pressure and to replace oil is usually the primary choice to enhance oil-recovery. Use of tracer methods is becoming an important part of the oil companies' basis for making economical decisions. Such water tracing requires passive tracers, i.e. compounds that behave exactly like the substance studied under the conditions of interest. This implies that a water-tracer in a water-flooded oil-field must fulfil requirements like no absorption to reservoir rock, no partitioning (or distribution) with respect to the other fluids present, long time thermal stability, microbial resistance and high detectability. In addition, the tracer compound has to be environmentally acceptable and available at a reasonable cost. Among the extensive number of compounds tested according to these criteria in the laboratory we have qualified four compounds as tracers for water in oil reservoirs. For three of them we propose radiolabelling syntheses with 14 C as radioactive label to lower detection limits. The compounds are benzene 1,2- and 1,3-dicarboxylic acids and benzene 1,3,5-tricarboxylic acid. (author)

Radon as tracer to identify discharge sections at Juatuba basin

International Nuclear Information System (INIS)

Chagas, Claudio Jose; Ferreira, Vinicius Verna Magalhaes; Fonseca, Raquel Luisa Mageste; Rocha, Zildete; Moreira, Rubens Martins; Lemos, Nayron Cosme; Menezes, Angela de Barros Correia; Santos, Talita Oliveira

2015-01-01

The use of natural tracers in hydrological studies is a very useful tool, being applied in several studies. One of these tracers is the radon, 222 Rn, noble gas derived from natural sources, been found in all underground waters, as a product of radioactive decay of the 226 Ra. This gas can be found in the air, water, rocks or soil. In this paper, the 222 Rn detection in surface water was used as tracer in order to identify aquifer discharge sections in surface water at the Fundao stream, which belongs to the Juatuba river basin, through the second semester of 2014 and the first semester of 2015, in three sampling campaigns. The 222 Rn measurements at Fundao stream were carried out using the equipment RAD 7. The results showed that 222 Rn is present in some sections of the water course suggesting that there is a connection between groundwater and surface water. It also justifies the variation in the water level in the stream, recorded by a fluviometric station. (author)

Radon as tracer to identify discharge sections at Juatuba basin

Energy Technology Data Exchange (ETDEWEB)

Chagas, Claudio Jose; Ferreira, Vinicius Verna Magalhaes; Fonseca, Raquel Luisa Mageste; Rocha, Zildete; Moreira, Rubens Martins; Lemos, Nayron Cosme; Menezes, Angela de Barros Correia, E-mail: vvmf@cdtn.br, E-mail: rlmf@cdtn.br, E-mail: cjc@cdtn.br, E-mail: rochaz@cdtn.br, E-mail: rubens@cdtn.br, E-mail: menezes@cdtn.br, E-mail: lemosnc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Santos, Talita Oliveira, E-mail: talitaolsantos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

2015-07-01

The use of natural tracers in hydrological studies is a very useful tool, being applied in several studies. One of these tracers is the radon, {sup 222}Rn, noble gas derived from natural sources, been found in all underground waters, as a product of radioactive decay of the {sup 226}Ra. This gas can be found in the air, water, rocks or soil. In this paper, the {sup 222}Rn detection in surface water was used as tracer in order to identify aquifer discharge sections in surface water at the Fundao stream, which belongs to the Juatuba river basin, through the second semester of 2014 and the first semester of 2015, in three sampling campaigns. The {sup 222}Rn measurements at Fundao stream were carried out using the equipment RAD 7. The results showed that {sup 222}Rn is present in some sections of the water course suggesting that there is a connection between groundwater and surface water. It also justifies the variation in the water level in the stream, recorded by a fluviometric station. (author)

Development of positron tracer for in vivo estimation of brain MAO-B activity

International Nuclear Information System (INIS)

Inoue, Osamu; Tominaga, Toshiyoshi; Fukuda, Nobuo; Suzuki, Kazutoshi; Yamasaki, Toshio

1984-01-01

Both the specificity and the measurable range of enzyme activity of this method were found to be much dependent upon the enzymatic properties of substrate-tracer. The measurable range of brain enzyme activity was found to be from zero to the maximum value which was dependent upon two factors; the elimination rate of substratetracer from the brain (Ksub(el)) and the Vsub(max)/Ksub(m) value of substrate. The detectable range of changes in enzyme activity can be made wider by using another substrate as a tracer which has a lower Vsub(max)/Ksub(m) value or larger Ksub(el) value. The specificity can be also favorably designed by selection of substrate with various enzymatic or physico-chemical properties as a tracer. N, N-dimethyl phenylethylamine (DMPEA) was selected as a substrate-tracer for the estimation of brain MAO-B activity. Very high accumulation of radioactivity into mouse brain at 1 min after intravenous injection of 11 C-DMPEA, and a long-term retention of radioactivity in the brain were observed. 11 C-DMPEA seemed to be metabolized to 11 C-dimethylamine by brain MAO, and be trapped by the blood-brain barrier. When various dosage of 1-deprenyl (a specific MAO-B inhibitor) were pretreated, brain radioactivity at 1 hr after injection of 11 C-DMPEA significantly decreased in a dosage (1-deprenyl)-dependent way, while pretreatment with clorgyline (a specific MAO-A inhibitor) had no effect. This decrease in radioactivity might be due to the decrease of the production rate of labeled metabolite ( 11 C-dimethylamine) in the brain. The relationship between the radioactivity remaining at 1 hr after injection and MAO-B activity remaining in the brain was quite paralle. 11 C-DMPEA seems to be a specific radiotracer for the external detection of alterations in MAO-B activity in the brain with a fair sensitivity. (J.P.N.)

Be-7 as a tracer for short-term soil surface changes - opportunities and limitations

Science.gov (United States)

Baumgart, Philipp

2013-04-01

Within the last 20 years the cosmogenic nuclide Beryllium-7 was successfully established as a suitable tracer element to detect soil surface changes with a high accuracy. Particularly soil erosion rates from single precipitation events are in the focus of different studies due to the short radioactive half-life of the Be-7 isotope. High sorption at topmost soil particles and immobility at given pH-values enable fine-scaled erosion modelling down to 2 mm increments. But some important challenging limitations require particular attention, starting from sampling up to the final data evaluation. E.g. these are the realisation of the fine increment soil collection, the limiting amount of measurable samples per campaign due to the short radioactive half-life and the specific requirements for the detector measurements. Both, the high potential and the challenging limitations are presented as well as future perspectives of that tracer method.

Contribution to investigations on trace elements transport in the Channel: spatial distribution of industrial tracers in mytilus edulis and fucus serratus

International Nuclear Information System (INIS)

Germain, P.; Masson, M.; Baron, Y.

1990-01-01

The distribution of artificial tracers - gamma emitters - has been studied in biological indicator species, mussels and fucus, along the french and english Channel shores in order to gain a better knowledge of trace elements transports in the Channel coastal areas. The main conclusions are supplied by 106 Ru-Rh and 60 Co. Extension of species labelling is larger eastwards than westwards, and the differences recorded between french and english shores show weak exchanges between south and north Channel; in the norman-breton gulf and in the Seine river bay, the distribution of radioactive tracers demonstrates complex current processes. The results are compared to the hydrodynamical studies carried out through models and follow-up of radioactive tracers in sea-water. Particular processes have been observed, corresponding to areas where the decay gradient from the source term is not respected (western Cotentin shore, western Seine Bay, Caux aerea). They are discussed in relation with fresh - sea water mixing, current and physico-chemical problems [fr

Elimination of nonspecific radioactivity from [{sup 76}Br]bromide in PET study with [{sup 76}Br]bromodeoxyuridine

Energy Technology Data Exchange (ETDEWEB)

Li Lu; Bergstroem, Mats E-mail: Mats.Bergstroem@pet.uu.se; Fasth, Karl-Johan; Wu Feng; Eriksson, Barbro; Laangstroem, Bengt

1999-10-01

[{sup 76}Br]Bromodeoxyuridine ([{sup 76}Br]BrdU) might allow a determination of proliferation in vivo using positron emission tomography (PET), but only with consideration of organ nonspecific radioactivity constituted by [{sup 76}Br]bromide. A first study assessed the potential of diuretics to eliminate [{sup 76}Br]bromide. [{sup 76}Br]Bromide was injected in the vein of rats and different diuretic combinations were given. Urine was collected and radioactivity measured. Torasemide plus sodium chloride gave better {sup 76}Br elimination than the other diuretics. In a second experiment, rats were given [{sup 76}Br]BrdU. After the radioactivity injection, the rats of the treatment group were given torasemide plus NaCl. At 44 h after the radioactivity injection, the radioactivity concentration and the fraction incorporated into DNA were measured in different organs. Using diuretics, the elimination of [{sup 76}Br]bromide was increased. The radioactivity decreased 30-50% in most of the organs but the highest radioactivity uptake was found in the organs with more active DNA synthesis. This method may facilitate the use of [{sup 76}Br]BrdU as a tracer for DNA synthesis using PET.

Reactivity of hydrogen contained in Raney nickel for ethylene hydrogenation studied by means of a tritium tracer

International Nuclear Information System (INIS)

Miyatani, Daisaku; Takeuchi, Toyosaburo.

1979-01-01

Reactivity of hydrogen contained in Raney nickel with ethylene was studied by using a tritium tracer. Hydrogen in Raney nickel was previously labeled with tritium and distinguished from hydrogen introduced during the hydrogenation reaction. The reactivity of the contained hydrogen was determined by measurement of the radioactivity of ethane produced in the hydrogenation. Ethylene reacted with hydrogen in Raney nickel for no supply of hydrogen during the hydrogenation. However, when ethylene was hydrogenated by both hydrogen in Raney nickel and introduced hydrogen, over 99% of the ethylene reacted with the introduced hydrogen and hardly reacted with the contained hydrogen. (author)

Measurement of distribution coefficients using a radial injection dual-tracer test

International Nuclear Information System (INIS)

Pickens, J.F.; Jackson, R.E.; Inch, K.J.; Merritt, W.F.

1981-01-01

The dispersive and adsorptive properties of a sandy aquifer were evaluated by using a radial injection dual-tracer test with 131 I as the nonreactive tracer and 85 Sr as the reactive tracer. The tracer migration was monitored by using multilevel point-sampling devices located at various radial distances and depths. Nonequilibrium physical and chemical adsorption effects for 85 Sr were treated as a spreading or dispersion mechanism in the breakthrough curve analysis. The resulting effective dispersivity values for 85 Sr were typically a factor of 2 to 5 larger than those obtained for 131 I. The distribution coefficient (K/sub d//sup Sr/) values obtained from analysis of the breakthrough curves at three depths and two radial distances ranged from 2.6 to 4.5 ml/g. These compare favorably with values obtained by separation of fluids from solids in sediment cores, by batch experiments on core sediments and by analysis of a 25-year-old radioactive waste plume in another part of the same aquifer. Correlations of adsorbed 85 Sr radioactivity with grain size fractions demonstrated preferential adsorption to the coarsest fraction and to the finest fraction. The relative amounts of electrostatically and specifically adsorbed 85 Sr on the aquifer sediments were determined with desorption experiments on core sediments using selective chemical extractants. The withdrawal phase breakthrough curves for the well, obtained immediately following the injection phase, showed essentially full tracer recoveries for both 131 I and 85 Sr. Relatively slow desorption of 85 Sr provided further indication of the nonequilibrium nature of the adsorption-desorption phenomena

Failure in the detection of the sentinel lymph node with a combined technique of radioactive tracer and blue dye in a patient with cancer of the vulva and a single positive lymph node

NARCIS (Netherlands)

Fons, G.; ter Rahe, B.; Sloof, G.; de Hullu, J.; van der Velden, J.

2004-01-01

Background. In early stage vulvar cancer, the sentinel lymph node procedure with a radioactive tracer appears to be a promising new diagnostic tool to predict lymph node status. No detection failures have been published so far in vulvar cancer. We recently experienced failure in the detection of the

Failure in the detection of the sentinel lymph node with a combined technique of radioactive tracer and blue dye in a patient with cancer of the vulva and a single positive lymph node

NARCIS (Netherlands)

Fons, G; ter Rahe, B; Sloof, G; de Hullu, J; van der Velden, J

Background. In early stage vulvar cancer, the sentinel lymph node procedure with a radioactive tracer appears to be a promising new diagnostic tool to predict lymph node status. No detection failures have been published so far in vulvar cancer. We recently experienced failure in the detection of the

Development of an activatable nanospheres tracer for use in industry and the environment

International Nuclear Information System (INIS)

Fonseca, Raquel Luiza M.; Moreira, Rubens M.; Moura, Igor Felipe S.

2015-01-01

Nanoparticles (NP's) can act as tracers for the study of several transport phenomena in industrial practice and environmental processes provided their physical and chemical properties meet specific requirements dictated by the application. Silica-coated gold nanoparticles in the size interval from 20 to 200 nm can be produced by gamma-ray irradiation. Submitted to neutron bombardment in a nuclear reactor, they will convert gold nuclides into 198 Au (E γ = 412 keV). These NP's can used as a tracer in oil fields, in petrochemical and refinery industrial processes in which conventional organic radioactive labeled compounds would not withstand, as well as in some hydrology and hydrogeology studies. (author)

Development of an activatable nanospheres tracer for use in industry and the environment

Energy Technology Data Exchange (ETDEWEB)

Fonseca, Raquel Luiza M.; Moreira, Rubens M., E-mail: rlmf@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SEMAM/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Departamento de Servico ao Meio Ambiente; Moura, Igor Felipe S., E-mail: igorfelipedx@yahoo.com.br [Universidade Federal de Minas Gerais (DEN/PCTN/UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

2015-07-01

Nanoparticles (NP's) can act as tracers for the study of several transport phenomena in industrial practice and environmental processes provided their physical and chemical properties meet specific requirements dictated by the application. Silica-coated gold nanoparticles in the size interval from 20 to 200 nm can be produced by gamma-ray irradiation. Submitted to neutron bombardment in a nuclear reactor, they will convert gold nuclides into {sup 198}Au (E{sub γ} = 412 keV). These NP's can used as a tracer in oil fields, in petrochemical and refinery industrial processes in which conventional organic radioactive labeled compounds would not withstand, as well as in some hydrology and hydrogeology studies. (author)

Concentration of radioactive cobalt by seaweeds in the food chain

International Nuclear Information System (INIS)

Nakahara, Motokazu; Koyanagi, Taku; Saiki, Masamichi

1976-01-01

On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link of food chain in the sea. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer expts. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26 through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (auth.)

Concentration of radioactive cobalt by seaweeds in the food chain

International Nuclear Information System (INIS)

Nakahara, M.; Koyanagi, T.; Saiki, M.

1975-01-01

On the pathway of radioactive substances in marine environments, seaweeds play an important role because of their higher concentration factors for many radionuclides and because they constitute a link in the food chain. In the present work, uptake, distribution and excretion of radioactive cobalt were studied on several kinds of seaweeds by radioisotope tracer experiments under laboratory conditions and concentration factors were calculated. The concentration factors were also estimated from the results of stable cobalt determination by activation analysis or atomic absorption spectrometry on seaweeds and seawater, and compared with the results of tracer experiments. The seaweeds showed the species specificity for the concentration of stable and radioactive cobalt with diverse values of concentration factors and biological half-lives. The transfer of radioactive cobalt in the food chain from contaminated seaweeds to mollusca was examined by feeding abalones, Haliotis discus, with four kinds of seaweed labelled with 60 Co and observing retention. Absorption rate for radioactive cobalt by abalones calculated at two days after feeding showed diverse values depending upon the species of seaweed, as follows: 47% through Laminaria japonica and Ulva pertusa, 31% through Undaria pinnatifida and 26% through Eisenia bicyclis, respectively. From the results, it was assumed that the accumulation of radioactive cobalt by mollusca is affected by the species of seaweeds as food. A very high concentration of ingested radioactive cobalt in the midgut gland was seen on the autoradiograph of abalone samples. (author)

The use radioactive tracers in the study of solid transport in water streams; Emploi de traceurs radioactifs pour l'etude du transport solide dans les cours d'eau

Energy Technology Data Exchange (ETDEWEB)

Courtois, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P; Heuzel, M [Laboratoire National d' Hydraulique de Chatou, 78 (France)

1960-07-01

The Laboratoire National d'Hydraulique which has been studying, during the last few years in conjunction with the Centre d'Etudes Nucleaires at Saclay, the development of apparatus and of methods of investigation of sediment transport by radioactive tracer techniques, is at the moment trying to perfect a genuinely quantitative method of investigation. Two experiments have recently been carried out in rivers, the first designed to investigate the transport of pebbles in the river Rhone, the other to investigate the movement of sands in the Niger. This second experiment has been supported by parallel experiments carried out on a reduced scale model of the Niger built at the laboratories of Chatou: in this experiment are used the radiation from {sup 56}Mn and {sup 24}Na obtained by direct activation of the crushed apricot store which represents, in the scale model, the natural sediment on the bed of the Niger. The combined efforts of the laboratories of Chatou and of the Centre d'Etudes Nucleaires at Saclay are at the moment directed to the application of radioactive tracers to studies on the scale models with the double aim: a) of having a single investigational method for the actual experiment and for the model making it possible to control the accuracy of the model in the preliminary stage of calibrating this model; b) of making the most of the possibilities of observation and of direct measurement offered by the scale models for studying the possibility of improving the tracer method, in particular with respect to the collecting of quantitative data. (author) [French] La Laboratoire National d'Hydraulique qui, depuis quelques annees a developpe, en collaboration avec le Centre d'Etudes Nucleaires de Saclay, les appareillages et les techniques d'etudes des mouvements de sediments par la methode des traceurs radioactifs, s'efforce actuellement de mettre au point un moyen d'investigation veritablement quantitatif. Deux experiences ont ete effectuees recemment en

Chemical and pharmacological aspects of cerebral tracers

International Nuclear Information System (INIS)

Rapin, J.R.; Duterte, D.; Le Poncin-Lafitte, M.; Coornaert, S.; Desplanches, G.; Bardy, A.; Moretti, J.L.; Raynaud, C.

1983-01-01

Among the iodophenylalkylamines studied and labelled with iodine 125 or iodine 123, N-isopropyl-iodo-amphetamin (IAMP) was selected and proposed as tracer for blood flow, a ''chemical embolus'' having almost 100% extraction in the brain. A new way of obtaining N-isopropyl-p-iodo-amphetamin is proposed and the easily-applied exchange reaction with iodine 125 or 123 gives product with a radiochemical purity of more than 96% and an unexchanged radioactive iodine content of less than 1%. The pharmacokinetic study of this product in the Wistar rat showed distribution in three compartments and the appearance of a steady state by the fourth minute. The target organs are the lungs, liver and brain. The latter receives 3% of the radioactivity and the autoradiographic study shows that the early distribution in the brain for IAMP closely equals the blood flow as found by a diffusible indicator. In the first hour, the redistribution is very low and at this time although IAMP is proposed for the study of regional blood flow, it does not exactly determine the flow but rather mirrors cell activity [fr

Water percolation conditions in Ilha Solteira dam (Parana River), using tracer techniques

International Nuclear Information System (INIS)

Sanchez, W.; Guidicini, G.; Silva, R.F. da.

1975-01-01

Radioisotopic techniques used in the study of water perconlation at the exact place of the construction of the canal lock of Ilha Solteira Dam, in its left side is presented. At the time of the drilling operations, it was discovered, by water leakage tests, total lost at 275,00 level. This water lost occurred at the vicinities of basalt lava-flows. The water leakage tests showed that the total absorption of pumping flow was about 80 liters per minute. To determine the velocity of water percolation in the probable cracks or fractures of the basalt a test of radioactive tracer 131 I was used. For the study of the radioactive tracer behaviour two techniques were tried: measurement of its dilution in the original of the well and the measurement of residence time. Results from the tests showed the existence of a crack or a set of cracks oriented from the radcoisotopic injection well to the artesian wells located at the left shore of Parana river, below Ilha Solteira Dam. The mentioned cracks are localized at the 272,00 level, close tr the contact between the basalt lava-flows

Study of cation diffusion in Zn O using {sup 65}Zn as radioactive tracer; Estudo da difusao cationica no Zn O com emprego de tracador radiativo {sup 65}Zn

Energy Technology Data Exchange (ETDEWEB)

Ferraz, Wilmar B.; Correa, Ricardo F. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Nogueira, Maria A.N.; Ramos, Marcelo; Sabioni, Antonio C.S. [Ouro Preto Univ., MG (Brazil). Dept de Fisica. Lab. de Difusao em Materiais

2000-07-01

Zinc self-diffusion coefficient were measured in polycrystalline Zn O of high purity (99,999%) prepared by conventional sintering at 1393 deg C, 4 h, in oxygen atmosphere. The Zn O samples had high density (>99% of the theoretical density) and grain size of 20 {mu}m. These samples were resintered for 72 h at 1400 deg C in order to increase the grain-size higher than 50 {mu} m. Samples of 15 x 15 x 2 mm{sup 3} were polished with diamond paste, and pre-annealed under the same conditions of temperature and atmosphere of the diffusion annealing. A thin film of {sup 65} Zn - radioactive tracer - applied to the polished surface was oxidized in oxygen atmosphere for a short time before diffusion annealing. The diffusion experiments were performed between 1002 and 1201 deg C in oxygen atmosphere. The {sup 65} Zn diffusion profiles were measured by sectioning in conjunction with residual-activity measurements. The results of the determination of the zinc in Zn O diffusion coefficients in function of temperature are presented and a comparison of these results obtained by the two radioactive method is showed. (author)

Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

International Nuclear Information System (INIS)

Scofield, P.A.

1986-01-01

The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

Iodine 123-antipyrine. A diffusible tracer for brain exploration

International Nuclear Information System (INIS)

Dantonel-Mathieu, Evelyne.

1978-09-01

Iodine 123-labelled iodoantipyrine is a liposoluble diffusible tracer which crosses the blood-brain barrier intact. Its build-up in brain tissue is proportional to the regional blood flow. Its behavior was studied in undervascularised brain lesions and in cases where research with traditional radioactive tracers (99mTc and its different vectors for example) has proved limited. Because of the great diffusibility of iodoantipyrine a brain parenchyma image is obtained within minutes after its injection, and this by the use of a non-invasive technique and under good gamma-camera exploration conditions. 81 brain explorations including 11 standards have been carried out on subjects averaging 51,2 years old; these examinations took place in three nuclear medicine centres. The 123 I iodoantipyrine used in each nuclear medicine centre is supplied by the CEA. Iodoantipyrine is labelled with a good yield (>98%) checked by chromatography by means of a CEA kit. After intraveinous injection of 4 to 6 mCi iodine-123 iodoantipyrine, a dynamic study (from 0 to 60 seconds) of the tracer passage in the brain tissue may be followed by static images taken in the next minutes according to a standard procedure. The table of results shows the major interest of this tracer for the exploration of vascular accidents with ischemic lesions, especially in the early phase of the accident. The lesion appears as a hypoactive zone and this lack of perfusion lasts for some minutes after the injection [fr

Biodistribution of [11C] methylaminoisobutyric acid, a tracer for PET studies on system A amino acid transport in vivo

International Nuclear Information System (INIS)

Sutinen, E.; Jyrkkioe, S.; Groenroos, T.; Haaparanta, M.; Lehikoinen, P.; Naagren, K.

2001-01-01

[N-methyl- 11 C]α-Methylaminoisobutyric acid ( 11 C-MeAIB) is a potentially useful tracer for positron emission tomography (PET) studies on hormonally regulated system A amino acid transport. 11 C-MeAIB is a metabolically stable amino acid analogue specific for system A amino acid transport. We evaluated the biodistribution of 11 C-MeAIB in rats and humans to estimate the usefulness of the tracer for in vivo human PET studies, for example, on regulation of system A amino acid transport and on tumour imaging. Healthy Sprague-Dawley rats (n=14) were killed 5, 20, 40 or 60 min after the injection of 11 C-MeAIB, and the tissue samples were weighed and counted for 11 C radioactivity. Ten lymphoma patients with relatively limited tumour burden underwent whole-body (WB) PET imaging with 11 C-MeAIB. In addition, three other patients had dynamic PET scanning of the head and neck area, and the tracer uptake was quantitated by calculating the kinetic influx constants (K i values) for the tracer. In animal studies, the highest activity was detected in the kidney, pancreas, adrenal gland and intestines. In humans, the highest activity was found in the salivary glands, and after that in the kidney and pancreas, similar to the results in animal studies. Rapid uptake was also detected in the skeletal muscle. In the graphical analysis, linear plots were obtained, and the mean fractional tracer uptake values (K i ) of the parotid glands (n=3) and cervical muscles (n=3) were 0.039±0.008 min -1 and 0.013±0.006 min -1 , respectively. The K i value of the tumour (n=1) was 0.064 min -1 . Higher uptake of 11 C-MeAIB into the tumour tissue was encountered. These results encourage further 11 C-MeAIB PET studies in humans on the physiology and pathology of system A amino acid transport and on tumour detection. (orig.)

Elemental concentrations and tracer uptake behavior of manganese, zinc, and selenium in brain of normal mice during development

International Nuclear Information System (INIS)

Tarohda, Tohru; Yabushita, Yuko; Kanayama, Yousuke; Amano, Ryohei; Enomoto, Shuichi

2001-01-01

Concentrations and uptake behavior of manganese (Mn), zinc (Zn), and selenium (Se) in mouse brain were studied by a multitracer technique, neutron activation analysis and autoradiography. Comparative concentrations on Mn, Zn, and Se and tracer uptake behavior of 54 Mn, 65 Zn, and 75 Se were examined in brains of 1-, 4-, 8-, 21-, and 56-day-old mice, and evaluated in terms of brain concentration (parts per million, ppm) and brain uptake rate (the radioactivity percentage of injected dose per gram of brain, %dose/g), respectively. As a result, the brain concentrations of Mn increased with growth, although those of Se and Zn did not change. On the other hand, the uptakes of the three tracers by brains of 1-day-old mice were much higher than those of older ones. Using radioactive 54 Mn as a single tracer, autoradiography was examined to determine the Mn uptake regional distribution in brains of 1-, 8-, and 21-day-old mice, and a higher regional uptake of Mn by the cerebral cortex, hippocampus, thalamus and hypothalamus in brains of young mice was observed. (author)

Analysis of metabolism of 6FDG: a PET glucose transport tracer

Energy Technology Data Exchange (ETDEWEB)

Muzic, Raymond F., E-mail: raymond.muzic@case.edu [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Chandramouli, Visvanathan [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Huang, Hsuan-Ming [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Wu Chunying; Wang Yanming [Department of Radiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Ismail-Beigi, Faramarz [Department of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

2011-07-15

Introduction: We are developing {sup 18}F-labeled 6-fluoro-6-deoxy-D-glucose ([{sup 18}F]6FDG) as a tracer of glucose transport. As part of this process it is important to characterize and quantify putative metabolites. In contrast to the ubiquitous positron emission tomography (PET) tracer {sup 18}F-labeled 2-fluoro-2-deoxy-D-glucose ([{sup 18}F]2FDG) which is phosphorylated and trapped intracellularly, the substitution of fluorine for a hydroxyl group at carbon-6 in [{sup 18}F]6FDG should prevent its phosphorylation. Consequently, [{sup 18}F]6FDG has the potential to trace the transport step of glucose metabolism without the confounding effects of phosphorylation and subsequent steps of metabolism. Herein the focus is to determine whether, and the degree to which, [{sup 18}F]6FDG remains unchanged following intravenous injection. Methods: Biodistribution studies were performed using 6FDG labeled with {sup 18}F or with the longer-lived radionuclides {sup 3}H and {sup 14}C. Tissues were harvested at 1, 6, and 24 h following intravenous administration and radioactivity was extracted from the tissues and analyzed using a combination of ion exchange columns, high-performance liquid chromatography, and chemical reactivity. Results: At the 1 h time-point, the vast majority of radioactivity in the liver, brain, heart, skeletal muscle, and blood was identified as 6FDG. At the 6-h and 24-h time points, there was evidence of a minor amount of radioactive material that appeared to be 6-fluoro-6-deoxy-D-sorbitol and possibly 6-fluoro-6-deoxy-D-gluconic acid. Conclusion: On the time scale typical of PET imaging studies radioactive metabolites of [{sup 18}F]6FDG are negligible.

Hybrid tracers for sentinel node biopsy

International Nuclear Information System (INIS)

Van Den Berg, N. S.; Kleinjan, G. I.; Valdés-Olmos, R. A.; Buckle, T.; Van Leeuwen, F. I.; Klop, W. M.; Horenblas, S.; Van Der Poel, H. G.

2014-01-01

Conventional sentinel node (SN) mapping is performed by injection of a radiocolloid followed by lymphoscintigraphy to identify the number and location of the primary tumor draining lymph node(s), the so-called SN(s). Over the last decade research has focused on the introduction of new imaging agents that can further aid (surgical) SN identification. Different tracers for SN mapping, with varying sizes and isotopes have been reported, most of which have proven their value in a clinical setting. A major challenge lies in transferring this diagnostic information obtained at the nuclear medicine department to the operating theatre thereby providing the surgeon with (image) guidance. Conventionally, an intraoperative injection of vital blue dye or a fluorescence dye is given to allow intraoperative optical SN identification. However, for some indications, the radiotracer-based approach remains crucial. More recently, hybrid tracers, that contain both a radioactive and fluorescent label, were introduced to allow for direct integration of pre- and intraoperative guidance technologies. Their potential is especially high when they are used in combination with new surgical imaging modalities and navigation tools. Next to a description of the known tracers for SN mapping, this review discusses the application of hybrid tracers during SN biopsy and how the introduction of these new techniques can further aid in translation of nuclear medicine information into the operating theatre.

Novel tracer for radiation treatment planning; Welche neuen PET-Tracer braucht die Strahlentherapie?

Energy Technology Data Exchange (ETDEWEB)

Schwarzenboeck, S.; Krause, B.J. [Rostock Univ. (Germany). Klinik fuer Nuklearmedizin; Herrmann, K.; Gaertner, F.; Souvatzoglou, M. [Technische Univ. Muenchen (Germany). Klinik fuer Nuklearmedizin; Klaesner, B. [Klinikum Bogenhausen, Muenchen (Germany). Inst. fuer Radiologie und Nuklearmedizin

2011-07-15

PET and PET/CT with innovative tracers gain increasing importance in diagnosis and therapy management, and radiation treatment planning in radio-oncology besides the widely established FDG. The introduction of [{sup 18}F]Fluorothymidine ([{sup 18}F]FLT) as marker of proliferation, [{sup 18}F]Fluoromisonidazole ([{sup 18}F]FMISO) and [{sup 18}F]Fluoroazomycin-Arabinoside ([{sup 18}F]FAZA) as tracer of hypoxia, [{sup 18}F]Fluoroethyltyrosine ([{sup 18}F]FET) and [{sup 11}C]Methionine for brain tumour imaging, [{sup 68}Ga]DOTATOC for somatostatin receptor imaging, [{sup 18}F]FDOPA for dopamine synthesis and radioactively labeled choline derivatives for imaging phospholipid metabolism have opened novel approaches to tumour imaging. Some of these tracers have already been implemented into radio-oncology: Amino acid PET and PET/CT have the potential to optimise radiation treatment planning of brain tumours through accurate delineation of tumour tissue from normal tissue, necrosis and edema. Hypoxia represents a major therapeutic problem in radiation therapy. Hypoxia imaging is very attractive as it may allow to increase the dose in hypoxic tumours potentially allowing for a better tumour control. Advances in hybrid imaging, i.e. the introduction of MR/PET, may also have an impact in radio-oncology through synergies related to the combination of molecular signals of PET and a high soft tissue contrast of MRI as well as functional MRI capabilities. (orig.)

Techniques and problems in studying intestinal absorption with radioactive isotopes in children

International Nuclear Information System (INIS)

James, W.P.T.; Waterlow, J.C.

1976-01-01

Radioactive isotopes give substantial promise for assisting the study of gastrointestinal absorption in children in that they allow reduction or elimination of the collection of blood, urine and faeces specimens. These operations are particularly difficult and unreliable in infants, on whom greatest interest in paediatric gastroenterology is centred in the tropics. Here intestinal malabsorption is most commonly associated with malnutrition, lactose intolerance, gastroenteritis, parasitic infestation and iron-deficiency anaemia. Two general techniques that have been employed are whole-body counting and analyses of 14 CO 2 exhaled in the breath after the feeding of 14 C-labelled nutrients. The former is advantageous if radionuclides suitable for the test at hand exist; the latter may be hard to interpret because of problems in the distribution and metabolism of the nutrient and intermediary products. Proper selection and understanding of the tests is particularly important in paediatric work, where the use of radioactive tracer techniques is unacceptable merely for the convenience of the investigator. (author)

Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131

International Nuclear Information System (INIS)

Wibagiyo

2004-01-01

Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131, carried out in 2002, the similar studies was also conducted in 2000 from subsurface river in Jurang Jero sinkhole, where the radioactivity appeared at Bribin cave 4 hours and 8 hours at Ngreneng cave. There is a question whether a subsurface river is flowing from Jurang Jero sinkhole to Bribin cave and then to Ngreneng cave, or from Jurang Jero sinkhole there is junction to Bribin and to Ngreneng. in 2002 a Germany team founded junction on up stream of river in Bribin cave, from the junction was carried out tracing which monitoring in Ngreneng cave. Where the result a junction connecting with Ngreneng cave, but the main stream in Bribin not connecting with Ngreneng. (author)

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

Use of naturally occurring helium to estimate ground-water velocities for studies of geologic storage of radioactive waste

International Nuclear Information System (INIS)

Marine, I.W.

1977-01-01

In a study of the potential for storing radioactive waste in metamorphic rock at the Savannah River Plant near Aiken, South Carolina, the rate of water movement was determined to be about 0.06 m/y by analyzing gas dissolved in the water. The gas contained up to 6 percent helium, which originated from the radioactive decay of natural uranium and thorium in the crystalline rock. The residence time of the water in the rock was calculated to be 840,000 years from the quantity of uranium and thorium in the rock, their rates of radioactive decay, and the quantity of helium dissolved in the water. The estimation of ground-water velocities by the helium method is more applicable to the assessment of a geologic site for storage of radioactive waste than are velocities estimated from packer tests, pumping tests, or artificial tracer tests, all of which require extensive time and space extrapolations

Elevated radon and thoron concentrations from natural radioactivity in building materials

International Nuclear Information System (INIS)

Smith, D.; Vivyurka, A.

1980-01-01

Radon levels in excess of 20 mWL were observed in an apartment building under construction in Elliot Lake. Tracer studies showed ventilation periods as long as 29 hours since the ventilation system of the building was not yet working. It was concluded that, once the contribution from thoron daughters was taken into account, the natural radioactivity of the concrete and other building materials was sufficient to produce the observed levels of radioactivity

Dependence of tracer diffusion on atomic size in amorphous Ni-Zr

International Nuclear Information System (INIS)

Hahn, H.; Averback, R.S.

1988-01-01

Tracer diffusion coefficients for several impurities and Ni self-atoms were measured in amorphous (a-) Ni/sub 50/Zr/sub 50/ at 573 K using secondary-ion-mass spectroscopy, Rutherford backscattering, and radioactive tracer methods. The results showed that atomic mobility in the a-Ni-Zr alloy depends strongly on atomic size, decreasing rapidly with increasing atomic radius. This diffusion behavior is similar to that in α-Zr and α-Ti and is suggestive of an interstitial-like mechanism of diffusion. The consequences of these results for solid-state amorphization transformations are discussed

Interwell tracer analyses of a hydraulically fractured granitic geothermal reservoir

International Nuclear Information System (INIS)

Tester, J.W.; Potter, R.M.; Bivins, R.L.

1979-01-01

Field experiments using fluorescent dye and radioactive tracers (Br 82 and I 131 ) have been employed to characterize a hot, low-matrix permeability, hydraulically-fractured granitic reservoir at depths of 2440 to 2960 m (8000 to 9700 ft). Tracer profiles and residence time distributions have been used to delineate changes in the fracture system, particularly in diagnosing pathological flow patterns and in identifying new injection and production zones. The effectiveness of one- and two-dimensional theoretical dispersion models utilizing single and multiple porous, fractured zones with velocity and formation dependent effects are discussed with respect to actual field data

The behavior of potassium in the blast furnace deduced from isotope tracers

International Nuclear Information System (INIS)

Barnes, I; Botha, D.W.S.; Farquharson, D.C.; Gordon, P.T.

1978-01-01

Two tracer tests were done with radioactive potassium (42 K) on blast furnace no. 1, Pretoria Works. Some 80% of the injected 42 K was recovered in 2 1/2 days. About 95% of both radioactive and natural potassium reported in the slag. Mean residence times of 18 and 25 hours confirmed the accumulation of potassium in the furnace. In these tests the slag basicity appeared to be an adequate indicator of furnace conditions governing the behaviour of potassium. A quantitative discontinious model with varying volume CSTR's and interflow controlled according to slag basicity - could be made to fit the results of both tests. The total amounts of K 2 O required by the model - 4 and 9 t respectively - were larger than estimates from input/output imbalance, or from mean residence time of the tracer

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

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.

Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

Science.gov (United States)

Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

2017-11-01

Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

Measurement of radioactive tracer microsphere blood from with NaI(Tl)- and Ge-well type detectors

International Nuclear Information System (INIS)

Winkler, B.; Staemmler, G.; Schaper, W.; Frank, J.; Langsdorf, S.

1982-01-01

An intrinsic Ge-well type detector was applied for the detection of gamma rays from labeled tracer microspheres. The high energy resolution and the large peak-to-Compton ratio of this spectrometer ensures the application of all available differently labeled tracer microspheres in one experiment. The superior energy resolution of the Ge-detector was documented with the separated photopeak regions of 103-Ru and 85-Sr-labeled tracer microspheres, which result in a single photopeak when an NaI(Tl) detector is used. The Ge-well type detector was compared with an NaI(Tl) spectrometer by counting samples of cardiac muscle in either spectrometer systems. Regression analysis between both spectrometer systems demonstrate identical flow values in these samples for 5 differently labeled tracer microspheres which were administered in 5 dogs. The high sensitivity of the Ge-well-type detector together with a suitable technique for sampling of myocardial tissue accomplishes a high spatial resolution of myocardial perfusion for all available differently labeled tracer microspheres. (orig.)

Evaluation of a radioactive and fluorescent hybrid tracer for sentinel lymph node biopsy in head and neck malignancies: prospective randomized clinical trial to compare ICG-{sup 99m}Tc-nanocolloid hybrid tracer versus {sup 99m}Tc-nanocolloid

Energy Technology Data Exchange (ETDEWEB)

Stoffels, Ingo; Leyh, Julia; Schadendorf, Dirk; Klode, Joachim [University Hospital Essen University of Duisburg-Essen, Department of Dermatology, Venerology and Allergology, Essen (Germany); University Duisburg-Essen, West German Cancer Center, Essen (Germany); German Cancer Consortium (DKTK), Essen (Germany); Poeppel, Thorsten [University Hospital Essen University of Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany)

2015-10-15

There is some controversy about the value of sentinel lymph node excision (SLNE) in patients with head and neck malignancies. The gold standard for detection and targeted extirpation of the SLN is lymphoscintigraphy with {sup 99m}Tc-nanocolloid. The purpose of this prospective randomized study was to analyse the feasibility and clinical benefit of a hybrid tracer comprising the near-infrared (NIR) fluorescent indocyanine green (ICG) and {sup 99m}Tc-nanocolloid (ICG-{sup 99m}Tc-nanocolloid) in direct comparison with standard {sup 99m}Tc-nanocolloid for guiding SLNE in patients with head and neck cutaneous malignancies. We analysed the data from 40 clinically lymph node-negative patients with melanoma, high-risk cutaneous squamous cell carcinoma, Merkel cell carcinoma or sweat gland carcinoma who underwent SLNE with ICG-{sup 99m}Tc-nanocolloid (cohort A) or with the standard {sup 99m}Tc-nanocolloid (cohort B). Overall SLNs were identified preoperatively in all 20 patients (100 %) in cohort A and in 18 of 20 patients (90 %) in cohort B. The SLN basin was detected preoperatively in 18 patients (90 %) in cohort A and also in 18 patients (90 %) in cohort B. SLNs were identified intraoperatively in all 20 patients (100 %) in cohort A and in 19 patients (95 %) in cohort B (p = 0.487). Metastatic SLNs were detected in 9 patients (22.5 %), 3 (15.0 %) in cohort A and 6 (30.0 %) in cohort B (p = 0.228). The hybrid tracer ICG-{sup 99m}Tc-nanocolloid is an innovative imaging tracer, reliably and readily providing additional information for the detection and excision of SLN in the head and neck region. Therefore, SLNE with combined radioactive and NIR fluorescence guidance is an attractive option for improving the SLN detection rate in patients with cutaneous head and neck malignancies. (orig.)

Nuclear medicine and coronary artery disease: evaluation of tracers of myocardial perfusion and vulnerable atherosclerotic plaque

International Nuclear Information System (INIS)

Broisat, A.

2005-04-01

Coronary artery disease is one of the primary cause of mortality worldwide. Nuclear medicine is the major imaging technique for diagnosis and following of this disease. perfusion: nowadays, major radioactive agents used in clinical practice are myocardial perfusion tracers. The reference tracer is thallium-201. However, 201 Tl presents some drawbacks. 99m Tcn-noet has been proposed for its replacement. This study shows that in contrast with previous studies realized in vitro on cardio myocytes, verapamil, an l-type calcium channel inhibitor, does not inhibit myocardial fixation of 99m Tcn-noet in vivo in dog. This data is in agreement with the hypothesis of a non specific endothelial fixation of this tracer. Moreover, this study shows that as a pure tracer of myocardial perfusion, 99m Tcn-noet can also be used to assess myocardial viability on a model of myocardial chronic infarction in rat. atherosclerosis: disruption of vulnerable atherosclerotic plaques is the main event leading to coronary accidents. The second part of this study concerns the evaluation of new potential tracers of the vulnerable atherosclerotic plaque in an experimental model of rabbit with an inheritable hypercholesterolemia. The four tracers evaluated (b2702(r), b2702-I, b2702-Tc and Tc-raft-b2702) are synthetic peptides comprising the residues 75-84 of hla-b2702, a molecule known to link vcam-1, an adhesion molecule expressed in vulnerable atherosclerotic plaque. The autoradiography studies show that all tracers accumulate within atherosclerotic plaque expressing vcam- and that. i-b2702 shows the best plaque/control fixation ratio. (author)

Chemical and pharmacological aspects of cerebral tracers

International Nuclear Information System (INIS)

Rapin, J.R.; Duterte, D.; Le Poncin-Lafitte, M.; Coornaert, S.; Desplanches, G.; Bardy, A.; Askienazy, S.; Moretti, J.L.; Raynaud, C.

1983-01-01

Among the iodophenylalkylamines studied and labelled with iodine 125 or iodine 123, N-isopropyl-iodo-amphetamin (IAMP) was selected and proposed as tracer for blood flow, a ''chemical embolus'' having almost 100% extraction in the brain. A new way of obtaining N-isopropyl-p-iodo-amphetamin is proposed and the easily-applied exchange reaction with iodine 125 or 123 gives a product with a radiochemical purity of more than 96% and an unexchanged radioactive iodine content of less than 1%. The pharmacokinetic study of this product in the Wistar rat showed distribution in three compartments and the appearance of a steady state by the fourth minute. The target organes are the lungs, liver and brain. The latter receives 3% of the radioactivity and the autoradiographic study shows that the early distribution in the brain for IAMP closely equal the blood flow as found by a diffusible indicator. In the first hour, the redistribution is very low and at this time although IAMP is proposed for the study of regional blood flow, it does not exactly determine the flow but allows the cell activity [fr

Rate equations for tracer studies in recirculating reactors

Energy Technology Data Exchange (ETDEWEB)

Happel, J [Columbia Univ., New York (USA). Dept. of Chemical Engineering

1974-10-01

The employment of isotopic tracers is a useful technique for gaining insight into the rate controlling steps of a complex chemical reaction such as is frequently encountered in heterogeneous catalysis. An effective procedure has been to superpose tracer transfer on a reaction which is occurring under steady state conditions. If tracer transfer is employed in this fashion it is often possible to assess the individual step velocities in an assumed reaction mechanism. If transient transfer of tracer is now introduced it is possible in addition to estimate surface concentrations of chemisorbed species. The purpose of the present paper is to present the mathematical relationships involved when transfer of the tracer is not differential in the investigation. For this purpose a simple example is chosen to illustrate the various possibilities involved.

Rate equations for tracer studies in recirculatinng reactors

International Nuclear Information System (INIS)

Happel, J.

1974-01-01

The employment of isotopic tracers is a useful technique for gaining insight into the rate controlling steps of a complex chemical reaction such as is frequently encountered in heterogeneous catalysis. An effective procedure has been to superpose tracer transfer on a reaction which is occurring under steady state conditions. If tracer transfer is employed in this fashion it is often possible to assess the individual step velocities in an assumed reaction mechanism. If transient transfer of tracer is now introduced it is possible in addition to estimate surface concentrations of chemisorbed species. The purpose of the present paper is to present the mathematical relationships involved when transfer of the tracer is not differential in the investigation. For this purpose a simple example is chosen to illustrate the various possibilities involved. (auth.)

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)

Microwave-acid treated bentonite as adsorbent for removal of radiocobalt from liquid radioactive waste

International Nuclear Information System (INIS)

Egamediev, S.; Nurbaeva, D.; Saidova, Z.; Khujaev, S.

2014-01-01

Full text : Development of new sorbents and study of its sorption properties is an important task for nuclear waste management. In this study it was examined the ability of modified bentonite clays to sorb 60Co radionuclide with aim to evaluate the possibility of using them as sorbents for treatment of radioactively contaminated solutions. The radioactive tracer technique was used for determination of distribution coefficients and to monitor the modification processes of bentonite

Feasibility of Real-Time Near-Infrared Fluorescence Tracer Imaging in Sentinel Node Biopsy for Oral Cavity Cancer Patients.

Science.gov (United States)

Christensen, Anders; Juhl, Karina; Charabi, Birgitte; Mortensen, Jann; Kiss, Katalin; Kjær, Andreas; von Buchwald, Christian

2016-02-01

Sentinel node biopsy (SNB) is an established method in oral squamous cell carcinoma (OSCC) for staging the cN0 neck and to select patients who will benefit from a neck dissection. Near-infrared fluorescence (NIRF) imaging has the potential to improve the SNB procedure by facilitating intraoperative visual identification of the sentinel lymph node (SN). The purpose of this study was to evaluate the feasibility of fluorescence tracer imaging for SN detection in conjunction with conventional radio-guided technique. Prospective study of patients with primary OSCC planned for tumor resection and SNB. Thirty patients were injected peritumorally with a bimodal tracer (ICG-99mTc-Nanocoll) followed by lymphoscintigraphy and SPECT/CT to define the SNs and their anatomic allocation preoperatively. SNs were detected intraoperatively with a hand-held gamma-probe and a hand-held NIRF camera. In 29 of 30 subjects (97%), all preoperatively defined SNs could be identified intraoperatively using a combination of radioactive and fluorescence guidance. A total of 94 SNs (mean 3, range 1-5) that were both radioactive and fluorescent ex vivo were harvested. Eleven of 94 SNs (12%) could only be identified in vivo using NIRF imaging, and the majority of those were located in level 1 close to the primary tumor. A combined fluorescent and radioactive tracer for SNB is feasible, and the additional use of NIRF imaging may improve the accuracy of SN identification in oral cancer patients. Intraoperative fluorescence guidance seems of particular value when SNs are located in close proximity to the injection site.

The discovery of radioactivity: a bend in sciences history

International Nuclear Information System (INIS)

Dautray, R.

1997-01-01

One hundred years after the discovery of radioactivity, it is possible to see what are the consequences of this discovery for the science. Four consequences are studied in this article: the acquisition of a new knowledge about matter and universe. Secondly, the observation that the radioactivity has given a clock of world history and open to us the past and how this past forged the present world. Thirdly, the fact that radioactivity gave tracers, markers which allow to sound the internal structure of the human body as well as these one of earth and solar system and to unveil the mechanisms. The fourth consequence, is all the applications, electro-nuclear energy, national defence, nuclear medicine. (N.C.)

Double tracer experiments to evaluate atmospheric transport and dose models

International Nuclear Information System (INIS)

Nielsen, S.P.; Gryning, S.-E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

1986-05-01

Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released simultaneously from a 110-m stack and detected downwind at distances of 3-4 km. The experiments were made at the Swedish nuclear power plant Ringhals in 1981. The radioactive tracer was routine emissions from unit 1 (BWR). The one-hour measurements yielded crosswind profiles at ground level of SF 6 -concentrations and of gamma radiation from the plume. The measured profiles were compared to profiles calculated with computer models. The comparison showed that the models sometimes underestimate and sometimes overestimate the results, which seems to indicate that the models within their limited accuracy yield unbiased results. The ratios between measured and calculated values range from 0.2 to 3. The measurements revealed a surplus of gamma radiations from the noble gas daughters compared to those from the gases. This was interpreted as due to ground desposition and the estimated deposition velocities range from 2 to 10 cm/s. The meteorological conditions were monitored from a 100-m meteorological tower and from an 11-m mast. Measurements were made of wind speed, wind direction, and temperatures at different heights, and during each experiment a mini-radiosonde was released giving information on a possible inversion layer. The SF 6 -tracer was injected to the stack prior to the experiments. Air-samples were collected downwind in plastic bags by radio-controlled sampling units. The SF 6 -concentrations in the bags were determined with gas chromatography. Measurements of the gamma radiation from the plume were made with ionisation chambers and GM-counters. Furthermore, a few mobile gamma spectrometers were available giving information on the unscattered gamma radiation, thereby permitting identification of the radioactive isotopes. The work was partly financed by the Nuclear Safety Board of the Swedish Utilities and by the Danish association of utilities in Jutland and on Funen, Elsam

Circulation of cerebrospinal fluid. Comparative study of various tracers

International Nuclear Information System (INIS)

Bok, B.; Thebault, B.; Cavailloles, F.; Aboulker, J.

1977-01-01

The dynamics of cerebrospinal fluid in the spinal subarachnoid space is studied by gammamyelography. There are still controversies about the ideal properties of the tracer to be used. The influence of the tracer's molecular weight on the kinetic of ascent in the medullar cerebrospinal fluid with a view to rating the criterias for choice of an available radiopharmaceutical was evaluated. Three compounds injected simultaneously through a lombar puncture were compared: indium 111 labelled transferrin, iodine 131 labelled human serum albumin and technetium 99m labelled diethylenetriaminepentaacetic acid. The individual stability of the compounds and a possible interference between them was investigated especially by electrophoretic technics. A spectrometric study showed that it is possible to simultaneously identify and count each of the isotopes included in the mixture on the detector device: an hybrid scanner. The comparison of linear activity profils collected on phantoms and on ten patients showed a similar fate of the three compounds during the first hours of the investigation studying the ascent of tracers into basal cisterns either in normal or pathological patients. It is therefore concluded that molecular weight does not influence in a detectable manner the spinal C.S.F. kinetics of the radiopharmaceuticals. This allows the use of the most convenient and best tolerated tracer from the dosimetric and toxicological stand point [fr

[18F]Fluoroethylflumazenil: a novel tracer for PET imaging of human benzodiazepine receptors

International Nuclear Information System (INIS)

Gruender, G.; Lange-Asschenfeldt, C.; Vernaleken, I.; Lueddens, H.; Siessmeier, T.; Buchholz, H.-G.; Bartenstein, P.; Stoeter, P.; Drzezga, A.; Roesch, F.

2001-01-01

5-(2'-[ 18 F]Fluoroethyl)flumazenil ([ 18 F]FEF) is a fluorine-18 labelled positron emission tomography (PET) tracer for central benzodiazepine receptors. Compared with the established [ 11 C]flumazenil, it has the advantage of the longer half-life of the fluorine-18 label. After optimisation of its synthesis and determination of its in vitro receptor affinities, we performed first PET studies in humans. PET studies in seven healthy human volunteers were performed on a Siemens ECAT EXACT whole-body scanner after injection of 100-280 MBq [ 18 F]FEF. In two subjects, a second PET scan was conducted after pretreatment with unlabelled flumazenil (1 mg or 2.5 mg i.v., 3 min before tracer injection). A third subject was studied both with [ 18 F]FEF and with [ 11 C]flumazenil. Brain radioactivity was measured for 60-90 min p.i. and analysed with a region of interest-oriented approach and on a voxelwise basis with spectral analysis. Plasma radioactivity was determined from arterial blood samples and metabolites were determined by high-performance liquid chromatography. In human brain, maximum radioactivity accumulation was observed 4±2 min p.i., with a fast clearance kinetics resulting in 50% and 20% of maximal activities at about 10 and 30 min, respectively. [ 18 F]FEF uptake followed the known central benzodiazepine receptor distribution in the human brain (occipital cortex >temporal cortex >cerebellum >thalamus >pons). Pretreatment with unlabelled flumazenil resulted in reduced tracer uptake in all brain areas except for receptor-free reference regions like the pons. Parametric images of distribution volume and binding potential generated on a voxelwise basis revealed two- to three-fold lower in vivo receptor binding of [ 18 F]FEF compared with [ 11 C]flumazenil, while relative uptake of [ 18 F]FEF was higher in the cerebellum, most likely owing to its relatively higher affinity for benzodiazepine receptors containing the α6 subunit. Metabolism of [ 18 F]FEF was very

Cobalt-57 as a SPET tracer in the visualization of ischaemic brain damage in patients with middle cerebral artery stroke

NARCIS (Netherlands)

Stevens, H; Knollema, S; Piers, DA; Van de Wiele, C; Jansen, HML; De Jager, AEJ; De Reuck, J; Dierckx, RA; Korf, J

In PET studies we have shown the usefulness of cobalt radionuclides for the visualization and quantification of ischaemic damage in stroke. In the present study, we explored Co-57(2+) as a SPET tracer. Uptake of radioactivity was estimated by using a cobalt enhancement ratio defined as the ratio of

Studies on the distribution of radioactivity in the organism during constant intravenous infusion of tracer amino acids and on the calculation of the rate of tissue protein synthesis in rats

International Nuclear Information System (INIS)

Simon, O.; Bergner, H.; Wolf, E.

1978-01-01

Male wistar rats (100 p body weight) were infused into the tail vein with 14 C-leucine and 14 C-lysine simultaneously for 0.5; 1.0; 2.0; 3.0; 4.5; 6.0 and 7.0 hours. At the end of the infusion the specific radioactivity was determined of the free leucine and lysine in the blood plasma, liver, M. gastrocnemius, small intestine, and colon as well as of the protein-bound leucine and lysine. In all the tissues tested the specific radioactivity of the free amino acids attained a plateau during the 6-hour and 7-hour infusions. The rate constants for the increase were calculated for each organ tested. The two amino acids used are suitable for calculating the fractional rate of protein synthesis in tissues. The values of the fractional rate of protein synthesis calculated on the basis of the 6-hour and 7-hour infusions were: 54+-7.7%/day for the liver, 9.4+-1.2%/day for the muscles, 89+-12.2%/day for the small intestine, and 42+-5.9%/day for the colon. The simultaneous application of two tracer amino acids is recommendable for estimating the precursor pool of the protein synthesis and the more accurate calculation of the rate of protein synthesis. (author)

Radioactive isotopes in solid-state physics

CERN Document Server

Deicher, M

2002-01-01

Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as M\\"ossbauer spectroscopy, perturbed angular correlation, $\\beta$-NMR, and emission channelling have used nuclear properties (via hyperfine interactions or emitted particles) to gain microscopical information on the structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as a clean ion beam at ISOL facilities such as ISOLDE at CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Extremely sensitive spectroscopic techniques like deep-level transient spectroscopy (DLTS), photoluminescence (PL), and Hall effect have gained a new quality by using radioactive isotopes. Because of their decay the chemical origin of an observed electronic and optical b...

Study of sediment behaviour in Rio de la Plata, Punta Carmelo area with use of radioactive trace

International Nuclear Information System (INIS)

Vianna Bandeira, J.; Godinho Pinto, G.; Suarez Antola, R.

1998-01-01

This work is related to the sedimentological studies with the application of radioactive tracers, carried out in the region of Puerto Carmelo, Rio de la Plata-Uruguay, under the Tc Project of the International Atomic Energy Agency (IAEA) URU/8/009, with the objective of evaluating the bed load transport of sand, in the region where a new access channel to the harbour of Carmelo, was designed. These studies, performed together hydraulic measurements, were important for the comprehension of the behaviour of the sediment transportation under the action of the hydrodynamic agents (currents and waves); the determination of the bed load rate and its application to the evaluation of the maintenance dredging, the definition of the optimum path for the access channel, based on the deposition process of the injected tracer, 30 cm above the bottom. The maximum accretion rate is for the designed channel is around 11000 m3/year. (author)

Basic study on behaviors of radioactive and toxic inorganic elements in environment, and environmental assessment for geological disposal of high-level radioactive wastes. Outline of the prize-winning study of the 12th Osaka Nuclear Science Corporation Prize

Energy Technology Data Exchange (ETDEWEB)

Fujikawa, Yoko; Kudo, Akira [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

1999-01-01

This study was made aiming to establish geological disposal technology for high-level radioactive wastes generated in nuclear power plant. A basic study for the technology was made using various radioactive materials containing Pu, U, Cs, Se, etc. as a tracer. First, adsorption mechanisms of various nuclides in ground water such as Cs, Co, Se, etc. onto rocks were investigated by indoor experiment. A certain correlation between the apparent adsorption rate of a nuclide onto rocks and diffusion coefficient into micropores in rocks was demonstrated both theoretically and experimentally. To estimate the radionuclide migration during more than one thousand years based on the results from indoor experiments is difficult, so that construction of a mathematical model was attempted to make numerical simulation. Thus,it was suggested that the properties of underground barrier are considerably related to the adsorption rates of nuclides and also diffusion coefficients into micropores. In addition, the effects of soil microorganisms and organic compounds on the behaviors of radioactive nuclides in soil ecosphere were investigated by extra-low level analysis of long-life radioactivities. More than 10% of Pu derived from Atomic Bomb at Nagasaki were found to be strongly bound to organic compounds in soils, showing that the element is extremely reactive with organic substances. (M.N.)

Deuterium used as artificial tracer in column studies under saturated water flow conditions

Science.gov (United States)

Koeniger, P.; Geiges, M.; Leibundgut, Ch.

2003-04-01

In contrast to numerous investigations using deuterium as an environmental tracer, hydrological investigations with deuterium-labelled water are rather rare. Currently applications in groundwater studies are restricted due to increasing costs of spiking large water quantities but an application as intelligent tracer might be of advantage especially in combination with other tracers and under distinct environmental conditions. Therefore deuterium was applied as artificial tracer in column experiments that are well proved as a tool to characterise tracer behaviour in recent studies. Deuterium was tested in comparison to the more familiar conservative tracer fluorescein. Varying experimental conditions, e.g. column length (0.5, 1.0, 1.5 m), initial tracer concentration (0.01, 0.02, 0.2 mg) and flow velocity (1.5 to 6.0 m/d) were used to investigate tracer behaviour under saturated water flow conditions. Deuterium was analysed using an H/Device with chrome reduction connected to an isotope ratio mass spectrometer and expressed in relative concentrations [per mill V-SMOW]. Theoretical tracer breakthrough curves were calculated using a one dimensional dispersion model. The results indicate higher mean transport velocities and smaller dispersion for deuterium in all experiments. Due to different molecule properties that also determine the interaction of soil substrate and tracer, deuterium indicates a more conservative transport behaviour. Deuterium is non-toxic, completely soluble, chemically and biologically stable and not subject to light-influenced decay. Furthermore, it shows promise for investigations of water flow in the unsaturated zone, and of interactions of water in soil-plant-atmosphere systems. A further discussion of problems, together with possibilities for applying deuterium as an artificial tracer, will be presented.

Analysis of blood clearance and labeled metabolites for the estrogen receptor tracer [F-18]-16α-fluorestradiol (FES)

International Nuclear Information System (INIS)

Mankoff, David A.; Tewson, Timothy J.; Eary, Janet F.

1997-01-01

[F-18] 16α-Fluoroestradiol (FES) has been shown to be a tracer of estrogen receptor content in breast tumors; however, quantitative analysis of FES images is complicated by the rapid metabolism of the tracer in vivo. To optimize FES PET imaging studies and to provide an input function for the quantitative analysis of the tracer FES uptake in breast tumors, we studied the clearance and metabolism of FES in 15 breast cancer patients. FES clearance, protein binding, and metabolite production and limited assays to determine the identity of labeled metabolites were performed. These studies show that FES was rapidly cleared from the blood and metabolized; at 20 min only 20% of the circulating radioactivity was unmetabolized FES, and much of this was protein bound. The detectable metabolites in either blood or urine are conjugation products, largely the glucuronide and the sulfate of FES, and these are excreted through the kidneys at a rate comparable to their introduction into the circulation. After 20 min postinjection the blood levels of radioactivity remain fairly constant. Our results, the first report on human metabolites, are in close agreement with previous animal studies of FES metabolism. These studies show that because FES clearance is rapid and metabolite background is nearly constant, imaging starting at 20 to 30 min after injection may provide good visualization of estrogen-containing tissues. Labeled metabolites need to be accounted for in quantifying FES uptake

An experimental study of tracers for labelling of injection gas in oil reservoirs

International Nuclear Information System (INIS)

Dugstad, Oe.

1992-01-01

This work demonstrates the feasibility of the PMCP and PMCH as tracers in field experiments. These compounds have properties which make them as well suited for well to well studies as the more common tracers CH 3 T and 85 Kr. In an injection project carried out at the Gullfaks field in the North Sea the two PFCs verified communication between wells. This implies communication between different geological layers in the reservoir and also communication across faults within the same layers. Laboratory studies carried out have focused on the retention of the tracers in dynamic flooding experiments under conditions comparable with those in the petroleum reservoirs. Simultaneous injection of a variety of tracers has shown individual variations in tracer retention which are caused by important reservoir parameters as fluid saturation and rock properties. By proper design of field injection programs the tracers response may therefore be used to estimate fluid saturation if actual rock properties are known. 45 refs., 20 figs., 13 tabs

Tracking of Radioactive Sources in Malaysian Nuclear Agency

International Nuclear Information System (INIS)

Mohd Fazlie Abdul Rashid; Noor Fadilla Ismail; Khairuddin Mohamad Kontol; Hairul Nizam Idris; Azimawati Ahmad; Suzilawati Muhd Sarowi; Raymond, Y.T.L.

2014-01-01

Radioactive materials are used in Malaysian Nuclear Agency for various purposes such as research and development, calibration, tracer and irradiation. Inventory of radioactive materials is crucial for ensuring the security and control of all radioactive materials owned and used so as not to be lost or fall into the hands of people who do not have permission to possess or use it. Experience in many countries around the world proves that the improper inventory of radioactive material would lead to loss of control of radioactive materials and will eventually cause an accident of radiation exposure. Radioactive material database has been developed for the need to ensure traceability of radioactive materials in Malaysian Nuclear Agency. Records of radioactive materials are regularly updated based on the classification of the type of radionuclide, the total distribution in each building and the initial activity of radioactive sources. (author)

TECHNOLOGY OF RADIATION MONITORING: TRACERS-INDICATORS OF DANGEROUS NATURAL AND TECHNOGENIC PHENOMENA

Directory of Open Access Journals (Sweden)

V. S. Yakovleva

2016-11-01

Full Text Available The analysis of results of experimental investigation concerning the influence of natural and technogenic events on radioactive gas and aerosols dynamics as well as structure and dynamics of different types of ionizing radiation in soil and ground atmosphere was performed. The results of the analysis were used to carry out of classification of revealed radiation tracersindicators of dangerous natural and technogenic phenomena. The algorithm of monitoring of optimum set of radiation tracers-indicators, which are measured simultaneously, of dangerous phenomena was developed. This algorithm uses the “2+1” rule for determining the optimum set of radiation tracers-indicators.

In vivo trace element speciation study by using enriched stable isotopic tracer technique

International Nuclear Information System (INIS)

Feng Weiyue; Chai Zhifang; Shi Junwen; Ding Wenjun

2005-01-01

In contrast to the radioactive tracer method, the enriched stable isotopic technique used in life sciences will not cause radiation damage to cells and its operation will be no radioactive risk, In our laboratory, the enriched stable isotopes Cr-50, Hg-196 and Hg-198 combined with biochemical separation, neutron activation analysis (NAA) and inductively coupled plasma mass spectrometry (ICP-IVIS) have been used to investigate the element speciation in vivo. Chromium (Cr) is proposed to act as a potentiator of insulin action in animals and human beings. Its deficiency induces the symptoms resembling diabetes and its supplement can alleviate these symptoms. However, as the concentration of Cr in vivo is usually at ultratrace level(- ng/g), its speciation study is usually difficult, since it is almost impossible to avoid the exogenous Cr contamination caused by separation and determination processes. Therefore, in this study, 50 Cr 2 O 3 with 94.2% 50 Cr was used as a tracer combined with gel chromatography to study the Cr speciation in serum, liver, urine and other tissues of healthy and diabetic rats. The Cr concentrations can be determined via 50 Cr(n, γ) 51 Cr by NAA, which is ideally suited for the ultratrace element analyses due to its high precision, accuracy and sensitivity. Such research have found that the most quantity of chromium in vivo is mainly combined with high molecular weight proteins, which is later identified as transferrin and low molecular weight protein is mainly excreted from urine. Mercury is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the global environment. Mercury compounds in the environment are often difficult to degrade. However, the mechanism on mercury toxicity to developing children following long term and low dose of mercury exposure is still not clear. Therefore, high sensitive method in vivo needs to be developed to study such low level mercury toxicity to fetus In this

Measurement of Kr-85 and Xe-133 as undisturbed tracers for the representing of atmospheric transport after disposal of radioactivity from nuclear facilities

International Nuclear Information System (INIS)

Frank, G.; Steinkopff, T.; Salvamoser, J.

2016-01-01

The Deutscher Wetterdienst (DWD, German Meteorological Service) operates since 1996 a sampling and measurement device for the radioactive rare gases Kr-85 and Xe-133 in Offenbach. These measurements are embedded in the German Measurement and Information System for Monitoring Environmental Radioactivity (Integriertes Mess- und Informationssystem zur Ueberwachung der Radioaktivitaet in der Umwelt, IMIS) [1]. In addition to these measurements the DWD is sampling rare gases in Potsdam and since 2014 in Trier in cooperation with the Bundesamt fuer Strahlenschutz (Federal Office for Radiation Protection, BfS). In the frame of the Global Atmosphere Watch (GAW)-program of the WMO the DWD operated a sampling station at the Zugspitze (Schneefernerhaus) from 1999 to 2005. This location at the Zugspitze is well suited for the observation of long distance transport of Kr-85 in the higher atmosphere. The DWD in Offenbach operates a complex analytical system for the measurement of Kr-85 and Xe-133 since 1998. This system consists of sampling with first enrichment, second enrichment, gas chromatographic separation and preparation of Krypton and Xenon and measurement of Kr-85 and Xe-133. Using the example Fukushima, it is shown, that the radioactive rare gases Kr-85 and Xe-133 are well undisturbed tracers for atmospheric transport in case of a nuclear accident or routine nuclear reprocessing plants. Measurements of Xe-133, I-131, Cs-137 and Kr-85 are correlated with source and atmospheric transport to the sampling sites at Offenbach and Potsdam.

Abstracts of the papers presented at the workshop 'synthesis and application of radioactively labelled organic compounds'

International Nuclear Information System (INIS)

1988-10-01

The abstracts of the 12 papers read at the Rossendorf workshop comprise syntheses and radioactive labelling of organic compounds such as herbicides, steroids, peptides and others and their application as tracers, above all in kinetic studies

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

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)

Influence of the radio-tracer used in diagnostic nuclear medicine upon the dose at the nucleus of cellular localisation

International Nuclear Information System (INIS)

Gardin, I.; Faraggi, M.; Stievenart, J.L; Le Guludec, D.; Bok, B.

1997-01-01

In the classical dosimetry one supposes a uniform distribution of the radio-pharmaceuticals at the source organ level as well as a homogeneous distribution of the absorbed dose. This hypotheses are not always verified in biology, and the influence of the tracer localisation on the dose delivered at the cellular nucleus has been studied. The average dose delivered by the electron emission of different radio-isotopes used in diagnosis has been calculated by taking into account the radioactivity localized upon the target cell (Dself), and upon the neighbouring cells (Dcross). Nuclear, cytoplasmic and membranous localizations of the tracer were simulated for different cellular sizes. In the particular case of 99m Tc and cells of nuclear radius about 4 μm and cellular radios about 8 μ, Dcross is independent of the intra-cellular localisation of the tracer. On the contrary, for a nuclear localisation Dself is 52 and 157 times more important than for the cytoplasmic and membranous localisation, respectively. The dose at the cellular nucleus due to electron emission of 99m Tc is under-estimated by a factor 2.6 by classical dosimetry when the radioactivity is nuclear. On the contrary, the classical model over-estimates by a factor 1.2 the dose at nucleus for cytoplasmic and membranous localizations. This study shows that the dose delivered at cellular nucleus by the electron emissions of 99m Tc depends on the localisation of the tracer. The modelling proposed allows a better evaluation of the radiobiological hazards related to the administration of radiopharmaceuticals in diagnostic nuclear medicine

Radioisotope tracer study of co-reactions of methanol with ethanol using 11C-labelled methanol over alumina and H-ZSM-5

International Nuclear Information System (INIS)

Sarkadi-Priboczki, E.; Kovacs, Z.; Kumar, N.; Salmi, T.; Murzin, D.Yu

2005-01-01

Complete text of publication follows. The transformation of methanol has been investigated over alumina and H-ZSM-5 in our previous experiments by 11 C-radioisotope tracing. The main product in methanol conversion over alumina was dimethyl ether due to Lewis acid sites while over H-ZSM-5 mostly hydrocarbons were formed due to both Lewis and Brrnsted acid sites. With increasing temperature first the ethanol was dehydrated to diethyl ether followed by ethene formation over alumina and H-ZSM-5. In this work, 11 C-labelled methanol as radioisotope tracer was added to non-radioactive methanol for investigation of co-reaction with non-radioactive ethanol over alumina and H- ZSM-5. The 11 C-methanol tracer was used to distinguish the methanol derivates and co-reaction derivates of methanol with ethanol against non-radioactive ethanol derivates. The yield of methyl ethyl ether as mixed ether and the influence of ethanol for the yields of C 1 -C 5 hydrocarbons were studied as a function of reaction temperature and contact time. The 11 C-methanol was formed by a radiochemical process from 11 CO 2 produced at cyclotron. The mixture of methanol and ethanol was added to 11 C-methanol and injected to the catalyst. The catalysis was carried out in a glass tube fixed-bed reactor after its pretreatment. The derivates were analyzed by radio-gas chromatography (gas chromatograph with thermal conductivity detector coupled on-line with a radioactivity detector). The comparative analysis of yields of radioactive and non-radioactive products as a function of reaction temperature gives information about the reaction pathways. Over alumina the yields of dimethyl ether and methyl ethyl ether (co-product) as radioactive and diethyl ether with ethene as non-radioactive main products were monitored as a function of reaction temperature and reaction time in the range of 513-593 K. Alongside ethanol derivates the ethene turns into main product in contrast with methyl ethyl ether and diethyl

Novel tracer for radiation treatment planning

International Nuclear Information System (INIS)

Schwarzenboeck, S.; Krause, B.J.; Herrmann, K.; Gaertner, F.; Souvatzoglou, M.; Klaesner, B.

2011-01-01

PET and PET/CT with innovative tracers gain increasing importance in diagnosis and therapy management, and radiation treatment planning in radio-oncology besides the widely established FDG. The introduction of [ 18 F]Fluorothymidine ([ 18 F]FLT) as marker of proliferation, [ 18 F]Fluoromisonidazole ([ 18 F]FMISO) and [ 18 F]Fluoroazomycin-Arabinoside ([ 18 F]FAZA) as tracer of hypoxia, [ 18 F]Fluoroethyltyrosine ([ 18 F]FET) and [ 11 C]Methionine for brain tumour imaging, [ 68 Ga]DOTATOC for somatostatin receptor imaging, [ 18 F]FDOPA for dopamine synthesis and radioactively labeled choline derivatives for imaging phospholipid metabolism have opened novel approaches to tumour imaging. Some of these tracers have already been implemented into radio-oncology: Amino acid PET and PET/CT have the potential to optimise radiation treatment planning of brain tumours through accurate delineation of tumour tissue from normal tissue, necrosis and edema. Hypoxia represents a major therapeutic problem in radiation therapy. Hypoxia imaging is very attractive as it may allow to increase the dose in hypoxic tumours potentially allowing for a better tumour control. Advances in hybrid imaging, i.e. the introduction of MR/PET, may also have an impact in radio-oncology through synergies related to the combination of molecular signals of PET and a high soft tissue contrast of MRI as well as functional MRI capabilities. (orig.)

Hanford facilities tracer study report (315 Water Treatment Facility)

International Nuclear Information System (INIS)

Ambalam, T.

1995-01-01

This report presents the results and findings of a tracer study to determine contact time for the disinfection process of 315 Water Treatment Facility that supplies sanitary water for the 300 Area. The study utilized fluoride as the tracer and contact times were determined for two flow rates. Interpolation of data and short circuiting effects are also discussed. The 315 Water Treatment Facility supplies sanitary water for the 300 Area to various process and domestic users. The Surface Water Treatment Rule (SWTR), outlined in the 1986 Safe Drinking Water Act Amendments enacted by the EPA in 1989 and regulated by the Washington State Department of Health (DOH) in Section 246-290-600 of the Washington Administrative Code (WAC), stipulates filtration and disinfection requirements for public water systems under the direct influence of surface water. The SWTR disinfection guidelines require that each treatment system achieves predetermined inactivation ratios. The inactivation by disinfection is approximated with a measure called CxT, where C is the disinfectant residual concentration and T is the effective contact time of the water with the disinfectant. The CxT calculations for the Hanford water treatment plants were derived from the total volume of the contact basin(s). In the absence of empirical data to support CxT calculations, the DOH determined that the CxT values used in the monthly reports for the water treatment plants on the Hanford site were invalid and required the performance of a tracer study at each plant. In response to that determination, a tracer study will be performed to determine the actual contact times of the facilities for the CxT calculations

[11C]UCB-A, a novel PET tracer for synaptic vesicle protein 2 A

International Nuclear Information System (INIS)

Estrada, Sergio; Lubberink, Mark; Thibblin, Alf; Sprycha, Margareta; Buchanan, Tim; Mestdagh, Nathalie; Kenda, Benoit; Mercier, Joel; Provins, Laurent; Gillard, Michel; Tytgat, Dominique; Antoni, Gunnar

2016-01-01

Introduction: Development of a selective and specific high affinity PET tracer, [ 11 C]UCB-A, for the in vivo study of SV2A expression in humans. Radiochemistry and preclinical studies in rats and pigs including development of a tracer kinetic model to determine V T . A method for the measurement of percent intact tracer in plasma was developed and the radiation dosimetry was determined in rats. Results: 3–5 GBq of [ 11 C]UCB-A could be produced with radiochemical purity exceeding 98% with a specific radioactivity of around 65 GBq/μmol. In vitro binding showed high selective binding towards SV2A. [ 11 C]UCB-A displayed a dose-dependent and reversible binding to SV2A as measured with PET in rats and pigs and the V T could be determined by Logan analysis. The dosimetry was favorable and low enough to allow multiple administrations of [ 11 C]UCB-A to healthy volunteers, and the metabolite analysis showed no sign of labeled metabolites in brain. Conclusions: We have developed the novel PET tracer, [ 11 C]UCB-A, that can be used to measure SV2A expression in vivo. The dosimetry allows up to 5 administrations of 400 MBq of [ 11 C]UCB-A in humans. Apart from measuring drug occupancy, as we have shown, the tracer can potentially be used to compare SV2A expression between individuals because of the rather narrow range of baseline V T values. This will have to be further validated in human studies.

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.

Storage of solid and liquid radioactive material

International Nuclear Information System (INIS)

Matijasic, A.; Gacinovic, O.

1961-01-01

Solid radioactive waste collected during 1961 from the laboratories of the Institute amounted to 22.5 m 3 . This report contains data about activity of the waste collected from january to November 1961. About 70% of the waste are short lived radioactive material. Material was packed in metal barrels and stored in the radioactive storage in the Institute. There was no contamination of the personnel involved in these actions. Liquid radioactive wastes come from the Isotope production laboratory, laboratories using tracer techniques, reactor cooling; decontamination of the equipment. Liquid wastes from isotope production were collected in plastic bottles and stored. Waste water from the RA reactor were collected in special containers. After activity measurements this water was released into the sewage system since no activity was found. Table containing data on quantities and activity of radioactive effluents is included in this report

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

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.

Predictions of PuO2 and tracer compound release from ISV melts

International Nuclear Information System (INIS)

Cronenberg, A.W.; Callow, R.A.

1992-04-01

Two field tests were conducted at the Idaho National Engineering Laboratory (INEL) to assess in situ vitrification (ISV) suitability for long-term stabilization of buried radioactive waste. Both tests contained rare-earth oxide tracers (DY 2 O 3 , Yb 2 O 3 , and Tb 4 O 7 ) to simulate the presence of plutonium in the form of PuO 2 . In the first test, Intermediate Field Test (IFT)-l, approximately 4-% release of tracer material occurred during soil melting and associated off-gassing, while essentially nil release was observed for the second experiment (IFT-2) for which off-gassing was much reduced. This report presents an evaluation of the IFT test data in terms of governing release processes. Prediction of tracer release during ISV melting centered on an assessment of three potential transport mechanisms, (a) tracer diffusion through stagnant pool, (b) tracer transport by convective currents, and (c) tracer carry-off by escaping gas bubbles. Analysis indicates that tracer release by escaping gas is the dominant release mechanism, which is consistent with video records of gas bubble escape from the ISV melt surface. Quantitative mass transport predictions were also made for the IFT-I test conditions, indicating similarity between the 4-% release data and calculational results at viscosities of ∼ poise and tracer diffusivities of ∼10 -6 CM 2 /s. Since PuO 2 has similar chemical and transport (diffusivity) properties as the rare-earth tracers used in the rare earth tracers used in the IFT experiments, release of PuO 2 is predicted for similar off-gassing conditions. Reduced off-gassing during ISV would thus be expected to improve the overall retention of heavy-oxides within vitrified soil

The use of 137Cs as a tracer in an erosion study in South Limburg (The Netherlands) and the influence of Chernobyl fallout

International Nuclear Information System (INIS)

Roo, A.P.J. de

1991-01-01

The 137 Cs radioactivity of soils was used as a tracer of soil erosion in a catchment in the Netherlands: 143 samples were analysed to map the 137 Cs redistribution using geostatistical interpolation methods. Caesium-137 activities on grassland are significantly higher than on arable land. Also, 137 Cs activities on waning slopes are higher and activities on steep slopes are lower. The soil erosion estimates; derived from the 137 Cs data, are used to validate the USLE erosion model. The recent Chernobyl nuclear accident also contributed to the 137 Cs activity. However, the Chernobyl input of 137 Cs, with a constant ratio of 1.765:1 to 134 Cs, cannot be used as a tracer of soil erosion. Because of the rapid decay of 134 Cs, it will not be possible to separate the sources of 137 Cs in the near future in areas significantly influenced by Chernobyl fallout and in these areas 137 Cs can no longer be used as a soil erosion tracer. (author)

Stable isotope usage in developing countries: Safe tracer tools to measure human nutritional status

International Nuclear Information System (INIS)

Klein, P.D.; Klein, E.R.

1987-01-01

How many calories are used when a nursing mother feeds her infant? How much milk does an infant receive in one week? What is the impact of the environment on the energy needs of children? How adequately does dietary protein sustain the synthesis of body constituents? What types of foods best nourish a child recovering from intestinal diseases such as diarrhoea? Quantitative answers to questions such as these can be obtained from the use of stable, non-radioactive isotopic tracers. Answers to these questions are important in assessing the nutritional status of infants, children, pregnant women and nursing mothers, as well as that of individuals who subsist on marginal food supplies. Because stable isotopic tracers are completely safe and without hazard, they can be used freely in health, nutrition, and agriculture studies in all populations

First preclinical evaluation of mono-[123I]iodohypericin as a necrosis-avid tracer agent

International Nuclear Information System (INIS)

Ni, Yicheng; Chen, Feng; Marchal, Guy; Huyghe, Dieter; Verbeke, Kristin; Verbruggen, Alfons M.; Bormans, Guy M.; Witte, Peter A. de; Nuyts, Johan; Mortelmans, Luc

2006-01-01

We have labelled hypericin, a polyphenolic polycyclic quinone found in St. John's wort (Hypericum perforatum), with 123 I and evaluated mono-[ 123 I]iodohypericin (MIH) as a potential necrosis-avid diagnostic tracer agent. MIH was prepared by an electrophilic radioiodination method. The new tracer agent was evaluated in animal models of liver infarction in the rat and heart infarction in the rabbit using single-photon emission computed tomography (SPECT), triphenyltetrazolium chloride (TTC) histochemical staining, serial sectional autoradiography and microscopy, and radioactivity counting techniques. Using in vivo SPECT imaging, hepatic and cardiac infarctions were persistently visualised as well-defined hot spots over 48 h. Preferential uptake of the tracer agent in necrotic tissue was confirmed by perfect match of images from post-mortem TTC staining, autoradiography (ARX) and histology. Radioactivity concentration in infarcted tissues was over 10 times (liver; 3.51% ID/g in necrotic tissue vs 0.38% ID/g in normal tissue at 60 h p.i.) and over 6 times (myocardium; 0.36% ID/g in necrotic tissue vs 0.054% ID/g in normal tissue; ratios up to 18 for selected parts on ARX images) higher than in normal tissues. The results suggest that hypericin derivatives may serve as powerful necrosis-avid diagnostic agents for assessment of tissue viability. (orig.)

Prediction of the fate of radioactive material in the South Pacific Ocean using a global high-resolution ocean model

International Nuclear Information System (INIS)

Hazell, Douglas R.; England, Matthew H.

2003-01-01

We investigate the release of radioactive contaminants from Moruroa Atoll in a global high-resolution off-line model. The spread of tracer is studied in a series of simulations with varying release depths and time-scales, and into ocean velocity fields corresponding to long-term annual mean, seasonal, and interannually varying scenarios. In the instantaneous surface release scenarios we find that the incorporation of a seasonal cycle greatly influences tracer advection, with maximum concentrations still found within the French Polynesia region after 10 years. In contrast, the maximum trace is located in the southeast Pacific when long-term annual mean fields are used. This emphasizes the importance of the seasonal cycle in models of pollution dispersion on large scales. We further find that during an El Nino/Southern Oscillation (ENSO) event reduced currents in the region of Moruroa Atoll result in increased concentrations of radioactive material in French Polynesia, as direct flushing from the source is reduced. In terms of the sensitivity to tracer release time-rates, we find that a gradual input results in maximum concentrations in the near vicinity of French Polynesia. This contrasts the instantaneous-release scenarios, which see maximum concentrations and tracer spread across much of the South Pacific Ocean. For example, in as little as seven years radioactive contamination can reach the east coast of Australia diluted by only a factor of 1000 of the initial concentration. A comparison of results is made with previous studies. Overall, we find much higher concentrations of radionuclides in the South Pacific than has previously been predicted using coarser-resolution models

Radioactive Particle Tracking (RPT): The Powerful Industrial Radiotracer Techniques for Hydrodynamics and Flow Visualization Studies

International Nuclear Information System (INIS)

Mohd Amirul Syafiq Mohd Yunos

2016-01-01

Full text: Radioactive particle tracking (RPT) techniques have been widely applied in the field of chemical engineering, especially in hydrodynamics in multiphase reactors. This technique is widely used to monitor the motion of the flow inside a reactor by using a single radioactive particle tracer that is neutrally buoyant with respect to the phase is used as a tracker. The particle moves inside the volume of interest and its positions are determined by an array of scintillation detectors counting in coming photons. Particle position reconstruction algorithms have been traditionally used to map measured counts rate into the coordinates by solving a minimization problem between measured events and calibration data. RPT have been used to validate respective-scale CFD models to partial success. This presentation described an introduction to radioactive particle tracking and summarizing a history of such developments and the current state of this method in Malaysian Nuclear Agency, with a perspective towards the future and how these investigations may help scale-up developments. (author)

Characterization of defects in semiconductors using radioactive isotopes

CERN Document Server

Deicher, Manfred

2007-01-01

Radioactive atoms have been used in solid-state physics and in material science for many decades. Besides their classical application as tracer for diffusion studies, nuclear techniques such as Mossbauer spectroscopy, perturbed angular correlation, and emission channeling have used nuclear properties to gain microscopical information on the structural and dynamical properties of solids. The availability of many different radioactive isotopes as a clean ion beam at facilities like ISOLDE/CERN has triggered a new era involving methods sensitive for the optical and electronic properties of solids, especially in the field of semiconductor physics. Spectroscopic techniques like photoluminescence (PL), deep-level transient spectroscopy (DLTS), and Hall effect gain a new quality by using radioactive isotopes. Due to their decay the chemical origin of an observed electronic and optical behavior of a specific defect or dopant can be unambiguously identified. This contribution will highlight a few examples to illustrat...

Semianalytical Solutions of Radioactive or Reactive Transport in Variably-Fractured Layered Media: 1. Solutes

International Nuclear Information System (INIS)

George J. Moridis

2001-01-01

In this paper, semianalytical solutions are developed for the problem of transport of radioactive or reactive solute tracers through a layered system of heterogeneous fractured media with misaligned fractures. The tracer transport equations in the non-flowing matrix account for (a) diffusion, (b) surface diffusion, (c) mass transfer between the mobile and immobile water fractions, (d) linear kinetic or equilibrium physical, chemical, or combined solute sorption or colloid filtration, and (e) radioactive decay or first-order chemical reactions. The tracer-transport equations in the fractures account for the same processes, in addition to advection and hydrodynamic dispersion. Any number of radioactive decay daughter products (or products of a linear, first-order reaction chain) can be tracked. The solutions, which are analytical in the Laplace space, are numerically inverted to provide the solution in time and can accommodate any number of fractured and/or porous layers. The solutions are verified using analytical solutions for limiting cases of solute and colloid transport through fractured and porous media. The effect of important parameters on the transport of 3 H, 237 Np and 239 Pu (and its daughters) is investigated in several test problems involving layered geological systems of varying complexity

Condensed matter physics with radioactive ion beams

International Nuclear Information System (INIS)

Haas, H.

1996-01-01

An overview of the present uses of radioactive ion beams from ISOLDE for condensed matter research is presented. As simple examples of such work, tracer studies of diffusion processes with radioisotopes and blocking/channeling measurements of emitted particles for lattice location are discussed. Especially the application of nuclear hyperfine interaction techniques such as PAC or Moessbauer spectroscopy has become a powerful tool to study local electronic and structural properties at impurities. Recently, interesting information on impurity properties in semiconductors has been obtained using all these methods. The extreme sensitivity of nuclear techniques makes them also well suited for investigations of surfaces, interfaces, and biomolecules. Some ideas for future uses of high energy radioactive ion beams beyond the scope of the present projects are outlined: the study of diffusion in highly immiscible systems by deep implantation, nuclear polarization with the tilted-foil technique, and transmutation doping of wide-bandgap semiconductors. (orig.)

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.

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

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.

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

Innovative use of a microbial tracer for measuring groundwater through a fractured matrix

International Nuclear Information System (INIS)

Strong-Gunderson, J.M.

1995-01-01

Site characterization for ground water remediation activities is limited by the one's ability to visualize the complexity of the subsurface environment. Currently, a variety of dyes, colloids, gases, etc., are used to monitor and estimate ground water flow and contaminant transport. The author has recently identified a new, innovative colloidal tracer that is a non-hazardous bacterium that is detectable at very low concentrations (ng/kg), and can provide real-time analysis (3--5 min) for measuring colloid transport. The tracer is the ice nucleating active (INA) bacterium Pseudomonas syringae. The assay conditions require measuring the freezing point of the sample (e.g., ground water and soil slurries). Typically, 10--100 microL drops of water will not freeze until -15 to -20 C. However, if the tracer is present the water will freeze at -3 to -7 C. This increase in the freezing point can only be due to the presence of the tracer and this phenomenon is well documented in the plant pathology and low-temperature biology literature but has only now been applied to site characterization and remediation activities. Laboratory experiments have identified the stability of the tracer in the presence of a variety of ground water contaminants (> 100 ppm) and it is stable over a pH range of 2.3--10.0. The tracer has been demonstrated in conjunction with other commonly used tracers at a variety of field sites: (1) a drilling tracer to identify potential cross contamination, and as a colloid/bacterial tracer in (2) a hydrofracturing demonstration, (3) a horizontal recirculation well system, (4) a fractured karst matrix, and (5) a radioactive contaminated site. The data from these demonstrations have provided additional information about site characteristics including faster ground water flow rates than previously identified and due to its low sensitivities better distribution into a clay matrix than estimated by the bromide tracer

Tracer measured substrate turnover requires arterial sampling downstream of infusion site

International Nuclear Information System (INIS)

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

1986-01-01

Measurement of metabolite turnover (Rt) with radioactive tracers is done by either infusing tracer venously and sampling specific activity (SA) arterially (V-A modes), or by infusing into the aorta and sampling venous blood (A-V mode). Using the Fick principle, the necessity for using the V-A mode can be demonstrated. If tracer is infused into the left ventricle, in a steady state the Rt is the product of arterial trace concentration, the cardiac output, and the tracer extraction ratio for the whole body. This is expressed as: Rt = Ca x Qx ((*Ca - *Cv)/*Ca) (Eq1) where C=trace concentration (μmol/ml), *C=tracer conc. (dpm/ml), a=arterial, v-=mixed venous, and Q=cardiac output (ml/min). Rearranging the equation: Rt = Qx(*Ca - *Cv)/SAa = F/SAa (Eq2) where SAa is *Ca/Ca, and Qx (*Ca-*Cv) equals the infusion rate (F). The authors compared Eqs1 and 2 (Rt = F/SAa) in 3 anesthetized dogs in which [1- 14 C] lactate was infused into the left ventricle, and blood was sampled arterially downstream from the infusion site and in the pulmonary artery. Eqs 1 and 2 gave similar results for Rt (45.9 vs. 43.9 μmol/kg min), while substituting SAv for SAa (A-V mode) into Eq 2 gave a higher Rt (53.6). When SAv (A-V mode) is used, the specific activity seen by the tissues (SAa) is not considered in the calculation of Rt. Therefore, only the V-A mode meets the requirements for tracer measured metabolite turnover

Data volume of atmospheric tracer studies at Lucas Heights, NSW, Australia -1996-1997

International Nuclear Information System (INIS)

Clark, G.H.; Stone, D.J.M.; Pascoe, J.H.

2000-01-01

A perfluorocarbon atmospheric tracer system has been used to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. Tracers have been released from two locations: a laboratory vent near the ridge of the Woronora river valley and from the HIFAR research reactor ventilation system. Most studies have been conducted during the early to late morning periods when valley influences might be expected on dispersion of the tracer plume. This report summarises the meteorological and tracer air concentration data and makes comparisons with estimates from a simple gaussian dispersion model. It is intended that the data will also be used for evaluation of more elaborate wind field and atmospheric models

Use of indium and rare-earths activable tracers for the evaluation of the hydraulic performance of wastewater treatment units

International Nuclear Information System (INIS)

Alvarenga, Gilmara Lucia Souza; Barreto, Alberto Avelar; Pinto, Amenonia Maria Ferreira; Moreira, Rubens Martins; Silva, Lauris Lucia da

2013-01-01

Efforts aimed at going deeper into the understanding of the purification processes of contaminated waters and at the optimization of both the technological and economic performance of such processes have been developed following the introduction of innovative wastewater treatment processes. Among the several wastewater depuration processes, this study focuses physical aspects of systems known as artificial wetlands and a special version of the anaerobic biological reactor. This biological reactor is of the upflow anaerobic sludge blanket (UASB) type, which is increasingly being utilized for the processing of urban wastewater. However, its effluent eventually needs some polishing to be performed at an artificial wetland stage. The hydrodynamic performances of both a special version of the UASB and a vegetated wetland have been studied using the tracer methodology, based on the impulse response of these systems. Both radioactive and activable tracers have been employed and had their information analyzed by appropriate software. Comments are presented on the advantages of the activable tracers. The results thus obtained have demonstrated the potential of the application of activable tracers in the experimental research of either natural or artificial hydraulic systems. (author)

Use of indium and rare-earths activable tracers for the evaluation of the hydraulic performance of wastewater treatment units

Energy Technology Data Exchange (ETDEWEB)

Alvarenga, Gilmara Lucia Souza; Barreto, Alberto Avelar; Pinto, Amenonia Maria Ferreira; Moreira, Rubens Martins, E-mail: gil_lsa@yahoo.com.br, E-mail: aab@cdtn.br, E-mail: amfp@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silva, Lauris Lucia da, E-mail: laurislsilva@yahoo.com.br [Universidade Federal de Minas Gerais (DQ/UFMG), Minas Gerais, MG (Brazil). Dept. de Quimica

2013-07-01

Efforts aimed at going deeper into the understanding of the purification processes of contaminated waters and at the optimization of both the technological and economic performance of such processes have been developed following the introduction of innovative wastewater treatment processes. Among the several wastewater depuration processes, this study focuses physical aspects of systems known as artificial wetlands and a special version of the anaerobic biological reactor. This biological reactor is of the upflow anaerobic sludge blanket (UASB) type, which is increasingly being utilized for the processing of urban wastewater. However, its effluent eventually needs some polishing to be performed at an artificial wetland stage. The hydrodynamic performances of both a special version of the UASB and a vegetated wetland have been studied using the tracer methodology, based on the impulse response of these systems. Both radioactive and activable tracers have been employed and had their information analyzed by appropriate software. Comments are presented on the advantages of the activable tracers. The results thus obtained have demonstrated the potential of the application of activable tracers in the experimental research of either natural or artificial hydraulic systems. (author)

Radionuclides as tracers of coastal processes in Brazil: review, synthesis, and perspectives

International Nuclear Information System (INIS)

Santos, Isaac R.; Burnett, William C.

2008-01-01

We review the usefulness, limitations, significance, and coastal management implications of radionuclide measurements in Brazilian coastal environments. We focus on the use of radionuclides as tracers of sedimentary processes and submarine groundwater discharge (SGD). We also discuss artificial radionuclide contamination and high natural radioactivity areas. The interpretation of 14 C-, 137 Cs-, and 210 Pb-derived sedimentation rates has provided evidence that inappropriate soil use by urban and agricultural activities has intensified erosion processes on land, which is reflected in depositional environments, such as coastal lagoons, estuaries and mangroves. Of the processes discussed in this paper, SGD is the one that requires the most scientific effort in the short-term. There have been only two case studies using 222 Rn and radium isotopes as groundwater tracers in Brazil. These investigations showed that SGD can be a major source of nutrients and other dissolved species to the coastal ocean. Baseline 137 Cs, 90 Sr, 239+240 Pu, and 238 Pu concentrations in seawater from the whole Brazilian coastal zone are very low. Therefore, in spite of contamination problems in many ecosystems in the northern hemisphere, artificial radionuclide pollution appears to be negligible along the Brazilian coast. Phosphate fertilizer industries and petroleum processing facilities are the main economic activities producing Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM). Even though a few attempts have been made to assess the radiological effects of these activities, their potential threats indicate a need for the radiological control of their wastes. This review showed that the number of studies within the field of environmental radioactivity is still small in Brazil and much more research is needed to understand processes of high interest for environmental managers. In the near future, it is likely that such studies in Brazil will move from descriptive

Radionuclides as tracers of coastal processes in Brazil: review, synthesis, and perspectives

Energy Technology Data Exchange (ETDEWEB)

Santos, Isaac R.; Burnett, William C., E-mail: santos@ocean.fsu.edu [Florida State University, Tallahassee, FL (United States). Dept. of Oceanography. Environmental Radioactivity Measurement Facility; Godoy, Jose M. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2008-04-15

We review the usefulness, limitations, significance, and coastal management implications of radionuclide measurements in Brazilian coastal environments. We focus on the use of radionuclides as tracers of sedimentary processes and submarine groundwater discharge (SGD). We also discuss artificial radionuclide contamination and high natural radioactivity areas. The interpretation of {sup 14}C-, {sup 137}Cs-, and {sup 210}Pb-derived sedimentation rates has provided evidence that inappropriate soil use by urban and agricultural activities has intensified erosion processes on land, which is reflected in depositional environments, such as coastal lagoons, estuaries and mangroves. Of the processes discussed in this paper, SGD is the one that requires the most scientific effort in the short-term. There have been only two case studies using {sup 222}Rn and radium isotopes as groundwater tracers in Brazil. These investigations showed that SGD can be a major source of nutrients and other dissolved species to the coastal ocean. Baseline {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu, and {sup 238}Pu concentrations in seawater from the whole Brazilian coastal zone are very low. Therefore, in spite of contamination problems in many ecosystems in the northern hemisphere, artificial radionuclide pollution appears to be negligible along the Brazilian coast. Phosphate fertilizer industries and petroleum processing facilities are the main economic activities producing Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM). Even though a few attempts have been made to assess the radiological effects of these activities, their potential threats indicate a need for the radiological control of their wastes. This review showed that the number of studies within the field of environmental radioactivity is still small in Brazil and much more research is needed to understand processes of high interest for environmental managers. In the near future, it is likely that such studies

Aluminum metabolism studied by [sup 26]Al tracer using AMS technique

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Hotta, Masayoshi; Ohashi, Hideo

1992-01-01

By accelerator mass spectrometry (AMS), we studied aluminum metabolism using [sup 26]Al as a tracer. To investigate the role of aluminum toxicity in the etiology of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, aluminum incorporation into the rat cerebrum was studied. When healthy rats were injected intraperitoneally with [sup 26]Al, a considerable amount of the tracer was incorporated into the brain within only 5 days after the injection. This [sup 26]Al accumulation was apparently irreversible, since it persisted even after 75 days. (author).

Strontium isotopes as natural tracers in reservoir oilfield and in groundwater systems

International Nuclear Information System (INIS)

Santos, Marcos E.; Palmieri, Helena E.L.; Moreira, Rubens M.

2009-01-01

The radioactive beta (β - ) decay of 87 Rb to 87 Sr is an important isotope system that has been widely applied for geochronological purposes and in identifying ground water sources, aquifer interactions and as a tracer for a secondary recovery process in offshore oilfields via seawater injection. The 87 Sr/ 86 Sr ratio of present seawater is constant worldwide, while formation waters in hydrocarbon reservoirs have various values are in most cases higher than modern seawater. This can be the basis for a natural tracer technique aiming at evaluating the performance of seawater injection processes by evaluating the 87 Sr/ 86 Sr ratio and the total Sr content of formation waters in the reservoir prior to injection, followed by monitoring these values in the produced water as injection proceeds. Inductively Couple Plasma Mass Spectrometry ICP-MS is a technique that has potential to be used in studies with tracers in the environment in the determination of isotope ratios and element traces in a sample. This work describes the methodology that will be used for the determination of variations in the isotopic composition of Sr and presents the preliminary results obtained determination of the strontium isotope ratios ( 87 Sr/ 86 Sr) using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). (author)

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.

Medical uses of radioactive calcium. Review of an IAEA programme to promote the applications of calcium-47

International Nuclear Information System (INIS)

1963-01-01

Calcium plays a number of biologically essential roles, which have long been under investigation by various techniques available to medical science. One of the most important of these techniques is radioactive tracer analysis, i. e. study of the functions of calcium within the body with the help of a radioactive isotope of the element. The calcium-47 programme of the International Atomic Energy Agency is intended to promote these investigations by facilitating the production and use of this isotope. The importance attached to calcium- 47 is due to the special properties of this isotope, which make it the most valuable tool for many calcium studies by the radioactive tracer method. The Agency has for four years been engaged in a comprehensive effort to bring calcium- 47 into routine medical use. To this end, it has surveyed the need for this isotope, stimulated its cheaper production, encouraged the investigation of its medical possibilities, and arranged for the dissemination of the information thus obtained. The fact that calcium-47 is no longer considered an exotic isotope is at least partly due to the Agency's efforts, in co-operation with interested scientists throughout the world

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)

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.)

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

A single hole tracer test to determine longitudinal dispersion

International Nuclear Information System (INIS)

Noy, D.J.; Holmes, D.C.

1986-03-01

The paper concerns a single hole tracer test to determine longitudinal dispersion, which is an important parameter in assessing the suitability of a site for radioactive waste disposal. The theory, equipment and procedure for measuring longitudinal dispersion in a single borehole is described. Results are presented for field trials conducted in an aquifer, where the technique produced good results. The measured value of longitudinal dispersion, from a single hole test, relates only to a limited volume of rock immediately adjacent to the borehole. (U.K.)

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

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.

A comparative evaluation of drilling techniques for deposits containing free gold using radioactive gold particles as tracers

International Nuclear Information System (INIS)

Clarkson, R.

1998-01-01

In the summers of 1992 and 1994, the author designed and carried out a statistically valid research program using radioactivated gold particles as tracers (radiotracers). Two types of fully cased normal circulation (N / C) drills, two types of reverse circulation (R/C) drills and three solid auger drills were evaluated under a variety of field conditions. A frozen cylindrical core of compacted gravels containing four sizes ( 1.2, 0.60, 0.30 and 0.15 mm), (+l4,+28,+48and+100 mesh)of radiotracers was placed in 44 drill holes and the holes were re drilled. Scintillometers were used to track free gold losses due to spillage and blow-by around the collar (top) of the hole. Some gold particles were located in temporary traps in the drilling equipment and these particles would have contaminated subsequent samples (as carry-over). Several myths commonly attributed to particular drilling methods were dispelled. There was no significant difference between the recovery of the four sizes of gold particles with any of the drills tested. Observations and down-hole scintillometer records indicated that the free gold particles did not follow the bit down the hole and were either carried out of the hole or forced onto the sides of the hole at or above the depth at which the radioactive gold was positioned. A comparative evaluation of the results of these tests is presented

Marine Radioactivity Studies in the Suez Canal, Part II: Field Experiments and a Modelling Study of Dispersion

Science.gov (United States)

Abril, J. M.; Abdel-Aal, M. M.; Al-Gamal, S. A.; Abdel-Hay, F. A.; Zahar, H. M.

2000-04-01

In this paper we take advantage of the two field tracing experiments carried out under the IAEA project EGY/07/002, to develop a modelling study on the dispersion of radioactive pollution in the Suez Canal. The experiments were accomplished by using rhodamine B as a tracer, and water samples were measured by luminescence spectrometry. The presence of natural luminescent particles in the canal waters limited the use of some field data. During experiments, water levels, velocities, wind and other physical parameters were recorded to supply appropriate information for the modelling work. From this data set, the hydrodynamics of the studied area has been reasonably described. We apply a 1-D-Gaussian and 2-D modelling approaches to predict the position and the spatial shape of the plume. The use of different formulations for dispersion coefficients is studied. These dispersion coefficients are then applied in a 2-D-hydrodynamic and dispersion model for the Bitter Lake to investigate different scenarios of accidental discharges.

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

Historical and contemporary stable isotope tracer approaches to studying mammalian protein metabolism

Science.gov (United States)

2016-01-01

Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward by the Nobel laureates JJ Thomson and FW Aston, enabling the accurate separation, identification, and quantification of the relative abundance of these isotopes. As a result, within a few years, the number of known isotopes both stable and radioactive had greatly increased and there are now over 300 stable or radioisotopes presently known. Unknown at the time, however, was the potential utility of these isotopes within biological disciplines, it was soon discovered that these stable isotopes, particularly those of carbon (13C), nitrogen (15N), oxygen (18O), and hydrogen (2H) could be chemically introduced into organic compounds, such as fatty acids, amino acids, and sugars, and used to “trace” the metabolic fate of these compounds within biological systems. From this important breakthrough, the age of the isotope tracer was born. Over the following 80 yrs, stable isotopes would become a vital tool in not only the biological sciences, but also areas as diverse as forensics, geology, and art. This progress has been almost exclusively driven through the development of new and innovative mass spectrometry equipment from IRMS to GC‐MS to LC‐MS, which has allowed for the accurate quantitation of isotopic abundance within samples of complex matrices. This historical review details the development of stable isotope tracers as metabolic tools, with particular reference to their use in monitoring protein metabolism, highlighting the unique array of tools that are now available for the investigation of protein metabolism in vivo at a whole body down to a single protein level

First preclinical evaluation of mono-[{sup 123}I]iodohypericin as a necrosis-avid tracer agent

Energy Technology Data Exchange (ETDEWEB)

Ni, Yicheng; Chen, Feng; Marchal, Guy [University Hospital Gasthuisberg, Department of Radiology, Leuven (Belgium); Huyghe, Dieter; Verbeke, Kristin; Verbruggen, Alfons M.; Bormans, Guy M. [University of Leuven, Laboratory of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Leuven (Belgium); Witte, Peter A. de [University of Leuven, Laboratory of Pharmaceutical Biology and Phytopharmacology, Faculty of Pharmaceutical Sciences, Leuven (Belgium); Nuyts, Johan; Mortelmans, Luc [University Hospital Gasthuisberg, Department of Nuclear Medicine, Leuven (Belgium)

2006-05-15

We have labelled hypericin, a polyphenolic polycyclic quinone found in St. John's wort (Hypericum perforatum), with{sup 123}I and evaluated mono-[{sup 123}I]iodohypericin (MIH) as a potential necrosis-avid diagnostic tracer agent. MIH was prepared by an electrophilic radioiodination method. The new tracer agent was evaluated in animal models of liver infarction in the rat and heart infarction in the rabbit using single-photon emission computed tomography (SPECT), triphenyltetrazolium chloride (TTC) histochemical staining, serial sectional autoradiography and microscopy, and radioactivity counting techniques. Using in vivo SPECT imaging, hepatic and cardiac infarctions were persistently visualised as well-defined hot spots over 48 h. Preferential uptake of the tracer agent in necrotic tissue was confirmed by perfect match of images from post-mortem TTC staining, autoradiography (ARX) and histology. Radioactivity concentration in infarcted tissues was over 10 times (liver; 3.51% ID/g in necrotic tissue vs 0.38% ID/g in normal tissue at 60 h p.i.) and over 6 times (myocardium; 0.36% ID/g in necrotic tissue vs 0.054% ID/g in normal tissue; ratios up to 18 for selected parts on ARX images) higher than in normal tissues. The results suggest that hypericin derivatives may serve as powerful necrosis-avid diagnostic agents for assessment of tissue viability. (orig.)

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)

Tracking groundwater discharge to a large river using tracers and geophysics.

Science.gov (United States)

Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

2014-01-01

Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings. © 2013, National Ground Water Association.

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)

Study on decontamination of radioactive ruthenium by steel wool in waste solution

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, S; Sakaki, T [Radia Industry Co. Ltd., Takasaki, Gunma (Japan)

1979-06-01

Tracer experiments were done in order to establish a decontamination process of /sup 106/Ru in radioactive waste solution by column method paying special attention on the solution of nitrato-nitrosyl complex of Ru which is often encountered as a low level radioactive solution. It turned out that metallic iron was the most effective decontaminating agent among the several tens of materials tested. The decontamination factor (DF) of /sup 106/Ru increased in proportion to the total surface area of iron and it sensitively depended on the oxidation state of the surface as revealed by the batchwise and columnwise tests. Iron samples with high corrosiveness gave a much larger DF than those with low corrosiveness. The decontamination process proceeded as iron was being oxidized via Fe(metal) ..-->.. Fe(II) ..-->.. Fe(III). As the results, the DF initially increased after initiating the passage of water through the column but it then decreased as the oxidation process became inactive. An excellent durability up to 10000 bed volumes was demonstrated by the column method at a high average DF of 150.

Hanford 100-N Area Tracer Study Final Report

International Nuclear Information System (INIS)

Kretzschmar, S.P.; Bedi, G.S.; Martinez, P.; Ervin, K.

1996-09-01

This document provides an engineering tracer study final report for the determination of contact time for the disinfection process at Group A Nontransient Noncommunity water treatment plant for the 100- N Water Plant (located on the Hanford Site in Richland, Washington). The purpose of this study is to determine the actual detention time within the plant clearwell, and the disinfection contact time at several clearwell effluent flow rates

Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966)

International Nuclear Information System (INIS)

Chesselet, R.

1969-01-01

The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [fr

Stable nuclide tracer studies and human amino acid requirements. A summary

International Nuclear Information System (INIS)

Young, V.R.

1994-01-01

The nutritional requirements for proteins have been estimated for various age groups. The current status of knowledge concerning the quantitative needs for specific indispensable amino acids was reviewed and it was concluded that, except for infants, current values for pre-school children, school age children and healthy adults are based on limited experimental data and/or on results from nitrogen balance determinations which are open to serious question regarding their nutritional significance. A review of 13 C-labelled tracer studies carried out in MIT laboratories was undertaken to demonstrate the applicability of stable nuclide tracer studies for purposes of determining the amino acid requirements of humans. 5 refs

Feasibility of Real-Time Near-Infrared Fluorescence Tracer Imaging in Sentinel Node Biopsy for Oral Cavity Cancer Patients

DEFF Research Database (Denmark)

Christensen, Anders; Juhl, Karina; Charabi, Birgitte

2016-01-01

BACKGROUND: Sentinel node biopsy (SNB) is an established method in oral squamous cell carcinoma (OSCC) for staging the cN0 neck and to select patients who will benefit from a neck dissection. Near-infrared fluorescence (NIRF) imaging has the potential to improve the SNB procedure by facilitating...... intraoperative visual identification of the sentinel lymph node (SN). The purpose of this study was to evaluate the feasibility of fluorescence tracer imaging for SN detection in conjunction with conventional radio-guided technique. METHODS: Prospective study of patients with primary OSCC planned for tumor...... be identified in vivo using NIRF imaging, and the majority of those were located in level 1 close to the primary tumor. CONCLUSIONS: A combined fluorescent and radioactive tracer for SNB is feasible, and the additional use of NIRF imaging may improve the accuracy of SN identification in oral cancer patients...

Studies of Tracer Dispersion and Fluid Flow in Porous Media

Energy Technology Data Exchange (ETDEWEB)

Rage, T.

1996-12-31

This doctoral thesis explores the connection between the topology of a porous medium and its macroscopic transport properties and is based on computerized simulation. In porous media, both diffusion and convection contribute to the dispersion of a tracer and their combined effect is emphasized. The governing equations are solved numerically, using finite differences and Monte Carlo technique. The influence of finite Reynolds number on the outcome of echo-experiments is discussed. Comparing experiments and simulations it is found that nonlinear inertial forces lead to a visible deformation of a returned tracer at surprisingly small Reynolds numbers. In a study of tracer dispersion and fluid flow in periodic arrays of discs it is demonstrated that the mechanisms of mechanical dispersion in periodic media and in natural (non-periodic) porous media are essentially different. Measurements of the percolation probability distribution of a sandstone sample is presented. Local porosity theory predicts that this simple geometric function of a porous medium is of dominant importance for its macroscopic transport properties. It is demonstrated that many aspects of transport through fractures can be studied by using simple but realistic models and readily available computer resources. An example may be the transport of hydrocarbon fluids from the source rock to a reservoir. 165 refs., 44 figs., 1 table

3. Radioactive pharmaceutical medications

International Nuclear Information System (INIS)

2006-01-01

In the chapter common definitions of for radio-pharmacy are given. Radio-pharmacy medications are pharmacy medications which contain minor amount of one or several radionuclides (radioactive tracers), those radiation ability is applying in diagnostic or therapeutic purposes. At the same time radionuclides with more short life time, which are ether gamma-radiators or beta-radiators are applying. The following items for such radioisotopes production; radionuclides applying in nuclear medicine; radio-pharmaceutics; radio-toxicity; quality insurance; order for 18 F-PDG production; radionuclide analysis are considered

Application of radioactive tracers in upgradation of industrial grade ion exchange resin (Amberlite IRA-400)

International Nuclear Information System (INIS)

Lokhande, R.S.; Singare, P.U.

1998-01-01

The exchange rates of ion exchange are determined by application of 131 I as a tracer isotope. The exchange study carried out in this investigation deals with understanding the effectiveness of ion exchange resin (in iodide form) Amberlite IRA-400 at different concentrations of potassium iodide solution (electrolyte) with temperature of solution varying from 27-48 degC by keeping amount of ion exchange resin constant (1.0 g). The exchange study is also carried out by varying amount of ion exchange resins, for fixed temperature (27.0 degC) and for fixed concentration of potassium iodide solution (0.005 M). (author)

Continuous administration of short-lived radioisotope tracers and the analogous Laplace transform

International Nuclear Information System (INIS)

Orr, J.S.

1979-01-01

Short-lived radioactive tracers are used because of the low radiation dose to patients. Another advantage finding increasing use, however, is that the equilibrium activities achieved by continuous administration to a steady state contain kinetic information. This is not the case with long-lived isotopes. The derivation of quantitative kinetic information in the form of rate constants or flows requires the formulation of a model of the system being studied. Several approaches to this have been published based on a model of single compartments with simultaneous arrival of tracer. To deal with more realistic models a method is proposed which uses the analogy between the procedure of continuous administration of short-lived tracer and the Laplace transform. This analogy permits all the theorems of Laplace transform theory to be applied to the analysis of measured activities. The basis of the analogy is explained and examples are given of its application to a number of models which represent actual physiology more realistically than single compartment models. In these applications the transformed equations representing the model, with measured values of activity inserted for each transform, are solved to derive the rate constants. This is different from the use of Laplace transforms where the constant coefficients are known and the initial value problem is solved to find the behaviour of the variables. (author)

Accountability of Radioactive Materials in Malaysian Nuclear Agency

International Nuclear Information System (INIS)

Noor Fadilla Ismail; Wan Saffiey Wan Abdullah; Khairuddin Mohamad Kontol; Azimawati Ahmad; Suzilawati Muhd Sarowi; Mohd Fazlie Abdul Rashid

2016-01-01

Radioactive materials possessed in Malaysian Nuclear Agency have many beneficial applications for research and development, calibration, tracer and irradiation. There are two types of radioactive materials which consist of sealed sourced and unsealed sourced shall be accounted for and secured at all the times by following the security aspect. The Health Physics Group in the Department of Radiation Safety and Health Division is responsible to manage the issues related to any accountability for all radioactive material purchased or received under the radioactive material protocol. The accountability of radioactive materials in Malaysian Nuclear Agency is very important to ensure the security and control the radioactive materials to not to be lost or fall into the hands of people who do not have permission to possess or use it. The accountability of radioactive materials considered as a mandatory to maintaining accountability by complying the requirements of the Atomic Energy Licensing Act 1984 (Act 304) and regulations made thereunder and the conditions of license LPTA / A / 724. In this report describes the important element of accountability of radioactive materials in order to enhances security standard by allowing tracking of the locations of sources and to reduce the risk of radioactive materials falling into the wrong hands. (author)

Tracer studies of flotation in the laboratory and in mineral processing plant

International Nuclear Information System (INIS)

Niemi, A.J.; Thereska, J.; Plasari, E.; Kacaj, M.

1993-01-01

Radioisotope tracers have a proven application for the extraction of residence time distributions and the evaluation of flotation rates in industry. This paper shows how values of the rate factor k are scaled up on the basis of flotation in the laboratory and tracer tests in plant. The procedure is illustrated by a theoretical study and by experimental data. The information obtained can be introduced into models of larger flotation systems. (author)

Can radiocaesium be used as a tracer for vegetal nutrients?

International Nuclear Information System (INIS)

Anjos, R. M.; Mosquera, B.; Carvalho, C.; Sanches, N.; Bastos, J.; Macario, K.; Vezzone, M.; Gomes, P.R.S.

2007-01-01

In recent years, there has been a growing interest in the evaluation of nutrient fluxes and radioactive contaminants in forest and agricultural ecosystems. Several studies on forest ecosystems have been carried out, mostly in Europe, after the Chernobyl accident. These studies have been performed mainly in the development of models for predicting the radiocaesium behavior in the soil and plant compartments of forest systems. However, research on the use of radiocaesium as a tracer for vegetal nutrients has shown that, despite the fact that caesium is a weakly hydrated alkaline metal and has chemical similarities to potassium and ammonium, this is still a complex problem requiring, then, more experimental results. Additionally, very little is known about the mechanisms involved in the radionuclide uptake and retention by tropical plants. In order to contribute to the understanding of the relative behavior of caesium, potassium and ammonium and to investigate whether radiocaesium can be used as a tracer for vegetal nutrients, the Laboratory of Radioecology (LARA) of the Federal Fluminense University has been performing analysis of 137 Cs, 40 K and NH 4 concentrations in several vegetal compartments of agricultural tropical plants, such as guava (Psidium guajava), mango (Mangifera indica), avocado (Persea americana), pomegranate (Punica granatum), papaya (Carica Papaya), banana (Musa paradisiaca), manioc (Manihot Esculenta), and chili pepper (Capsicum fructescens) trees. Measurements of 137 Cs, 40 K and NH 4 concentrations show that these elements can be very mobile within a plant, exhibiting the highest values of concentration in the growing parts of the trees: fruits, leaves, twigs, barks and the outer growth layers. On the other hand, our results indicate that for wood trees (such as guava, mango, avocado, pomegranate and chili pepper trees) do both caesium and the vegetal nutrients have simultaneously higher concentrations in the youngest rather than in the oldest

Contribution of the radioactive tracer techniques to the littoral management

International Nuclear Information System (INIS)

Alami, R.

1994-01-01

The construction of a harbor or its extending, the management of entrance channels and their maintenance (e.g. dredging works), the littoral development for industrial or tourist purposes, the management of urban or industrial rejects are very expensive and have a great impact on the environment, the optimization of which requires to begin with understanding and making sure of the sedimentary mechanisms occurring under the natural conditions. The tracer techniques are, in such cases, a precious tool and a unique help to the decision makers. The profits made by using such techniques in Morocco, which is a seaboard country, have led the C entre National de l'Energie, des Sciences et des Techniques Nucleaires (CNESTEN) to set up a unit which is operational in this field. 7 figs., 8 refs (F.M.)

Tritium as tracer of groundwater pollution extension: case study of Andralanitra landfill site, Antananarivo-Madagascar

Science.gov (United States)

Ramaroson, Voahirana; Rakotomalala, Christian Ulrich; Rajaobelison, Joel; Fareze, Lahimamy Paul; Razafitsalama, Falintsoa A.; Rasolofonirina, Mamiseheno

2018-05-01

This study aims to understand the extension of groundwater pollution downstream of a landfill, Andralanitra-Antananarivo-Madagascar. Twenty-one samples, composed of dug well waters, spring waters, river, and lake, were measured in stable isotopes ( δ 2H, δ 18O) and tritium. Results showed that only two dug well waters, collected at the immediate vicinity of the landfill, have high tritium activities (22.82 TU and 10.43 TU), probably of artificial origin. Both upstream and further downstream of the landfill, tritium activities represent natural source, with values varying from 0.17 TU to 1.46 TU upstream and from 0.88 TU to 1.88 TU further downstream. Stable isotope data suggest that recharge occurs through infiltration of slightly evaporated rainfall. Using the radioactive decay equation, the calculated tracer ages related to two recent ground water samples collected down gradient of the landfill lay between [8-15] years and [4-7] years, taking into account the uncertainty of tritium measurements. For the calculation, a value of 2.36 TU was taken as A o. The latter was estimated based on similarity between stable isotope compositions of nearby spring and dug well waters as well as tritium activities of the local precipitation. Calculation of the tritium activities from the contaminated water point having 22.82 TU to further downstream using the calculated tracer ages showed values of one order of magnitude higher than the measured values. The absence of hydrological connection from the contaminated water point to further downstream the landfill would explain the lower tritium activities measured. Groundwater pollution seems to be limited to the closest proximity of the landfill.

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

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

Some examples of the use of radioactive tracers in pharmacodynamic

International Nuclear Information System (INIS)

Cohen, Y.

1960-01-01

The study of absorption, of distribution in the organism and of the elimination of a medicament has been greatly facilitated by the development of nuclear applications. In effect, the introduction into the molecule of one or several radioactive atoms makes it possible to follow the path and destination of minute quantities of the drug and to thus carry out analyses on the animal within limits of posology close to those of therapeutics. However the qualitative or quantitative methods used have certain limits and they must be compared amongst themselves and with others. Some examples will show : - the importance of the way of administering the drug on the changes in the distribution; - the quite relative selectivity of this latter; - and lastly, the different process involved in the elimination mechanisms. (author) [fr

Comparison of the image-derived radioactivity and blood-sample radioactivity for estimating the clinical indicators of the efficacy of boron neutron capture therapy (BNCT): 4-borono-2-18F-fluoro-phenylalanine (FBPA) PET study.

Science.gov (United States)

Isohashi, Kayako; Shimosegawa, Eku; Naka, Sadahiro; Kanai, Yasukazu; Horitsugi, Genki; Mochida, Ikuko; Matsunaga, Keiko; Watabe, Tadashi; Kato, Hiroki; Tatsumi, Mitsuaki; Hatazawa, Jun

2016-12-01

In boron neutron capture therapy (BNCT), positron emission tomography (PET) with 4-borono-2- 18 F-fluoro-phenylalanine (FBPA) is the only method to estimate an accumulation of 10 B to target tumor and surrounding normal tissue after administering 10 B carrier of L-paraboronophenylalanine and to search the indication of BNCT for individual patient. Absolute concentration of 10 B in tumor has been estimated by multiplying 10 B concentration in blood during BNCT by tumor to blood radioactivity (T/B) ratio derived from FBPA PET. However, the method to measure blood radioactivity either by blood sampling or image data has not been standardized. We compared image-derived blood radioactivity of FBPA with blood sampling data and studied appropriate timing and location for measuring image-derived blood counts. We obtained 7 repeated whole-body PET scans in five healthy subjects. Arterialized venous blood samples were obtained from the antecubital vein, heated in a heating blanket. Time-activity curves (TACs) of image-derived blood radioactivity were obtained using volumes of interest (VOIs) over ascending aorta, aortic arch, pulmonary artery, left and right ventricles, inferior vena cava, and abdominal aorta. Image-derived blood radioactivity was compared with those measured by blood sampling data in each location. Both the TACs of blood sampling radioactivity in each subject, and the TACs of image-derived blood radioactivity showed a peak within 5 min after the tracer injection, and promptly decreased soon thereafter. Linear relationship was found between blood sampling radioactivity and image-derived blood radioactivity in all the VOIs at any timing of data sampling (p radioactivity measured in the left and right ventricles 30 min after injection showed high correlation with blood radioactivity. Image-derived blood radioactivity was lower than blood sampling radioactivity data by 20 %. Reduction of blood radioactivity of FBPA in left ventricle after 30 min of FBPA

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

Radiation exposure in an urban dwelling following an accidental release of radioactivity

International Nuclear Information System (INIS)

Cannell, Robert J.

1988-01-01

The intent of this work is the improved knowledge of how much protection would be afforded to the occupants of a dwelling in the event of a release of radioactivity into the environment. Fundamental to this is the question of how radioactive aerosols and dusts outside of a dwelling affect the inhabitants, what proportion of and by what routes radioactive materials penetrate the structural fabric of the dwelling, and again, how these materials affect the occupants once inside the dwelling. Whilst related research has already provided some answers to this question, experimental work on the tracking of radioactive materials or their analogues was, and still is, required. The major effort of this research has been in the development of an image gathering and processing system which provides a measurement of the mass and spatial distribution of a fluorescent tracer deposited on a surface. Although capable of further refinement, the technique is usable experimentally and its initial use in studying the transport of tracer analogues of radioactive materials is described. One of the main determinants of the behaviour of aerosols is their deposition rate and measurements of this rate for several aerosol-bound radionuclides were made in a test house. The results of these measurements and the dust transport experiments are collated and together with current values from the literature provide the input data for a computer house model. This simple house model has been developed with the primary purpose of indicating which parameters, specifically related to the characteristics of a dwelling, are most influential in determining what degree of protection the occupants will gain. The estimates of protection resulting from the model are summarised, and its sensitivity to the input parameters is used to indicate where further experimental work needs to be undertaken. (author)

Studies of the analytical chemistry on filter paper. XVI. Paper chromatography of radioactive substance. Radiochemical studies on ''Bikini ashes''

Energy Technology Data Exchange (ETDEWEB)

Nakano, S

1956-01-01

Radioactivity from ''Bikini ashes'' and /sup 235/U fission is divided into 3 major groups by ion-exchange methods and then subdivided by paper chromatography. In the first group, TeO/sub 4/--, SO/sub 4/--, PO/sub 4//sup 3/-, and I-, as well as two /sup 106/Ru spots, are resolved in filter paper by iso-AmOH. /sup 137/Cs and /sup 144/Ce from the second and /sup 90/Y and /sup 90/Sr from the third group are separated also. It is shown that the presence of carrier or foreign elements alters the chromatographic behavior of the tracers.

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)

Radiochemical studies on corrosion products of oral biomaterials

International Nuclear Information System (INIS)

Madbouly, H.A.Abdallah

1998-01-01

The work given in this thesis deals with a radioactive tracer study of the sorption of the corrosion products of dental amalgams and antimony on human teeth, porcelain and acrylic materials, used as dental restorative material. Sorption was investigated in presence of water and liquids commonly intaken by man; namely tea with or without sugar, soluble coffee ( Nescaffee) with or without sugar and/or milk, red tea (karkadeh or hibiscus) with or without sugar and chicken soup. The radioactive isotopes of Ag, Sn, Zn (amalgam components) and antimony were prepared by their irradiation in the nuclear reactor; 110m Ag, 113 Sn, 65 Zn and 124 Sb were thereby produced. The percent uptake of each studied element was evaluated from the depletion of radioactivity of the corresponding radioactive tracer in the given medium containing a tooth (human or artificial)

Measurement of Kr-85 and Xe-133 as undisturbed tracers for the representing of atmospheric transport after disposal of radioactivity from nuclear facilities; Messungen von Kr-85 und Xe-133 als ungestoerte Tracer zur Darstellung atmosphaerischer Transportvorgaenge nach Freisetzung von Radioaktivitaet aus kerntechnischen Anlagen

Energy Technology Data Exchange (ETDEWEB)

Frank, G.; Steinkopff, T. [Deutscher Wetterdienst (Germany); Salvamoser, J. [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen (IGU), Woerthsee (Germany)

2016-07-01

The Deutscher Wetterdienst (DWD, German Meteorological Service) operates since 1996 a sampling and measurement device for the radioactive rare gases Kr-85 and Xe-133 in Offenbach. These measurements are embedded in the German Measurement and Information System for Monitoring Environmental Radioactivity (Integriertes Mess- und Informationssystem zur Ueberwachung der Radioaktivitaet in der Umwelt, IMIS) [1]. In addition to these measurements the DWD is sampling rare gases in Potsdam and since 2014 in Trier in cooperation with the Bundesamt fuer Strahlenschutz (Federal Office for Radiation Protection, BfS). In the frame of the Global Atmosphere Watch (GAW)-program of the WMO the DWD operated a sampling station at the Zugspitze (Schneefernerhaus) from 1999 to 2005. This location at the Zugspitze is well suited for the observation of long distance transport of Kr-85 in the higher atmosphere. The DWD in Offenbach operates a complex analytical system for the measurement of Kr-85 and Xe-133 since 1998. This system consists of sampling with first enrichment, second enrichment, gas chromatographic separation and preparation of Krypton and Xenon and measurement of Kr-85 and Xe-133. Using the example Fukushima, it is shown, that the radioactive rare gases Kr-85 and Xe-133 are well undisturbed tracers for atmospheric transport in case of a nuclear accident or routine nuclear reprocessing plants. Measurements of Xe-133, I-131, Cs-137 and Kr-85 are correlated with source and atmospheric transport to the sampling sites at Offenbach and Potsdam.

Radioisotope tracer study in an aniline production reactor

International Nuclear Information System (INIS)

Pant, H.J.; Yelgoankar, V.N.; Mendhekar, G.N.

1995-01-01

A radioisotope tracer study was carried out in an aniline production reactor to investigate the cause of poor heat transfer from tube side to shell side in an aniline production (ANPO) reactor. The results of the study indicated that more than 50% of the shell volume was reduced due to deposition of the process material (i.e. fouling) on the shell walls and may be the cause of poor heat transfer in the reactor. (author). 2 refs., 2 figs

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

Synthesis and characterization of scandium oxide microspheres for their application in radioactive particle tracking experiments

International Nuclear Information System (INIS)

Goswami, Sunil; Biswal, Jayashree; Pant, H.J.; Pillai, K.T.; Bamankar, Y.R.

2012-01-01

Radioactive particle tracking (RPT) technique, proposed by Lin et al., is a noble technique for understanding mixing mechanisms of fluids and; evaluation and improvement of design of multiphase flow systems. In RPT technique the motion of a single radioactive particle is tracked in a flow system using an array of strategically mounted NaI(Tl) scintillation detectors around the system. The gamma emitting radioactive tracer particle being tracked is designed to be hydrodynamically similar to that of the phase being traced

Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain Site characterization study

International Nuclear Information System (INIS)

Dombrowski, T.; Stetzenbach, K.

1993-01-01

This report is in two parts one for the fluorinated benzoic acids and one for the fluorinated aliphatic acids. The assumptions made in the report regarding the amount of tracer that will be used, dilution of the tracer during the test and the length of exposure (if any) to individuals drinking the water were made by the authors. These assumptions must really come from the USGS hydrologists in charge of the c-well tracer testing program. Accurate estimates of dilution of the tracer during the test are also important because of solubility limitations of some of the tracers. Three of the difluorobenzoic acids have relatively low solubilities and may not be usable if the dilution estimates are large. The toxicologist that reviewed the document agreed with our conclusion that the fluorinated benzoic and toluic acids do not represent a health hazard if used under the conditions as outlined in the report. We are currently testing 15 of these compounds, and if even if three difluorobenzoic acids cannot be used because of solubility limitations we will still have 12 tracers. The toxicologist felt that the aliphatic fluorinated acids potentially present more of a health risk than the aromatic. This assessment was based on the fact of a known allergic response to halothane anesthetic. This risk, although minimal, is known and he felt that was enough reason to recommend against their use. The authors feel that the toxicologists interpretation of this risk was overly conservative, however, we will not go against his recommendation at this time for the following reasons. First, without the aliphatic compounds we still have 12 to 15 fluorinated aromatic acids which, should be enough for the c-well tests. Second, to get a permit to use aliphatic compounds would undoubtedly require a hearing which could be quite lengthy

Potential study of bed filtration characteristics in impressed boreholes by radon tracer technique

International Nuclear Information System (INIS)

Litvinov, A.A.; Pinkenzon, D.B.; Makarov, M.S.; Vinarskij, M.S.

1977-01-01

Potential study of bed filtration characteristics in impressed boreholes by radon tracer method is shown. Effects recorded by radon tracer result from gamma radiation of short-living radon decay daughter products. During filtration of tracer through punched holes, cement stone, and rocks the products are deposited and cause a local effect for 2-3 hours. There is a shortage of short-living products in filtrated radon liquid and for some time (which is necessary for production of notable quantity of new decay products) it is practically not a gamma emitter. It is shown that the feature of effect formation governs the technique for well logging as well as interpretation of the results obtained

18F-labelled annexin V: a PET tracer for apoptosis imaging

International Nuclear Information System (INIS)

Murakami, Yoshihiro; Tatsumi, Mitsuyoshi; Ichise, Rikiya; Nishimura, Shintaro; Takamatsu, Hiroyuki; Noda, Akihiro; Taki, Junichi; Tait, Jonathan F.

2004-01-01

Annexin V can be used to detect apoptotic cells in vitro and in vivo, based on its ability to identify extracellular phosphatidylserine, which arises during apoptosis. In the present study, we examined the synthesis of fluorine-18 labelled annexin V as a positron emission tomography tracer for apoptosis imaging. The distribution of [ 18 F]annexin V and technetium-99m labelled annexin V, a well-characterised SPET tracer for apoptosis imaging, was compared. [ 18 F]annexin V was synthesised using N-succinimidyl 4-[ 18 F]fluorobenzoate as an 18 F labelling reagent. Synthesised and purified [ 18 F]annexin V was confirmed by SDS-PAGE. In an ex vivo imaging experiment, [ 18 F]annexin V was intravenously injected into rats 24 h after the induction of myocardial ischaemia, and accumulation in the left ventricle was examined. [ 18 F]annexin V accumulated in the infarct area of the left ventricle, where apoptotic cells were observed. In separate experiments, [ 18 F]annexin V or [ 99m Tc]annexin V was intravenously injected into ischaemic or normal animals, and the distribution of the tracers was compared. In ischaemic animals, accumulation of [ 18 F]annexin V and [ 99m Tc]annexin V in the infarct area was about threefold higher than in the non-infarct area. Furthermore, the ratio of accumulation in the normal heart to the blood radioactivity was not significantly different between the tracers. In normal animals, however, the uptake of [ 18 F]annexin V in the liver, spleen and kidney was much lower than that of [ 99m Tc]annexin V. The low uptake of [ 18 F]annexin V in these organs might represent an advantage over [ 99m Tc]annexin V. (orig.)

Aligning Higher Education to Workforce Needs in Liberia: A Tracer Study of University Graduates in Liberia

Science.gov (United States)

Flomo, John S., Jr.

2013-01-01

This study investigated the congruence between higher education and the labor market from the perspectives of college graduates in Liberia. It specifically examined the alignment of the skills college students acquire in college to Liberia's labor market. The study employed a Tracer Study quantitative research methodology. Tracer study as a…

The use of tracers in the study of the ionic permeability of the nerve

International Nuclear Information System (INIS)

Guinnebault, M.

1961-01-01

The use of the radioactive tracers 24 Na and 42 K, and the electrophysiological fine study carried out on the plant Cephalopods nervous cells have made it possible, during ten years, to study the relationships between the electrical phenomena observed during the propagation of the nervous impulse and the ionic movements which occur at the cell membrane between the intra- and extra-cellular media. In the state of rest, the nerve fibres present a certain permeability towards sodium and potassium, a permeability which allows the renewal, from the extra-cellular medium, of the cations contained in the cytoplasm. At the moment of the passage of the nervous impulse, it is possible to demonstrate a temporary increase in the permeability towards the sodium which causes the entry of Na + ions into the nerve fibre, whilst, a few milliseconds later, the increase in the potassium permeability causes the departure of an equivalent quantity of K + ions. A recovery phase follows the passage of the nervous impulse, during which the original ionic conditions are re-established. If the potassium movements can be considered as passive, the expulsion of Na + requires, on the part of the cell, the use of a part of the metabolic energy. (author) [fr

Ca2+ influx and efflux in animal cells in the presence of panax notoginseng extracts: investigated by using 45Ca as a radioactive tracer

International Nuclear Information System (INIS)

Yang Yuanyou; Liu Ning; Mo Shangwu; Liao Jiali; Xu Falun

2010-01-01

In this paper, the influence of extracts of Panax notoginseng on Ca 2+ influx and efflux in isolated rat visceral organs was investigated by using 45 Ca as a radioactive tracer. The results indicated that both extracts, the total flavonoids and total saponins of Panax notoginseng had significant influence on Ca 2+ influx and efflux in the isolated rat aorta, heart, and kidney, in those organs it could markedly block 45 Ca entering into cell and could facilitate efflux of intracellular Ca 2+ . Compared with the total flavonoids, total saponins had stronger role in the regulation of Ca 2+ influx and efflux. Also, regulation effects of Ca 2+ influx and efflux of the total saponins were compared with positive drug Verapamil, or even better. This implies that the total flavonoids and total saponins of Panax notoginseng have calcium antagonistic effect, and both may be the active ingredients in Panax notoginseng for coronary heart disease treatment. (authors)

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

Laboratory studies into the use of the scandium-46-EDTA complex as a tracer for groundwater flow

International Nuclear Information System (INIS)

Cheng, H.; Nixon, S.C.

1988-01-01

Gamma ray emitting metal radionuclides, when complexed with an appropriate complexing agent, provide a wide choice of water tracers particularly for groundwater studies where a radionuclide of appropriate half-life suited to the particular study can be selected. Scandium-46 has easily detectable gamma emission and a suitable half-life (84 days) for medium term studies. It has been widely and successfully used as a tracer in studies of sediment movement but has not yet been introduced as a groundwater tracer. In our experiments the chemical aspects of the preparation of Sc-46-EDTA were studied in some detail and its behaviour in various mineralogical environments was evaluated with reference to the standard tracer, tritiated water. The experimental results have shown that the scandium cation can be easily complexed with EDTA to form soluble SC-EDTA. The complex is very stable in a wide range of pH; the adsorptive properties of Sc-EDTA in the batch studies and the retardation and recovery in the column tests in comparison with tritiated water are quite satisfactory. In general Sc-46-EDTA is a promising tracer for groundwater studies. In the report the appropriate conditions, procedures and some rational and efficient methods for testing the purity of Sc-46-EDTA in the preparation of the tracer solution of Sc-46-EDTA are described. In addition, it has been found that the formation of the metal hydroxide colloids is the major reason for the great loss in groundwater aquifers of most trivalent metal nuclide tracers in the cationic form including scandium-46. (author). 29 refs, 11 figs, 12 tabs

Exploration by radioactive fibrinogen of intrarenal coagulation phenomena. Preliminary results

International Nuclear Information System (INIS)

Simon, Jacques.

1974-01-01

The participation of fibrin deposits in kidney pathology was studied by the use of a radioactive tracer involved in the coagulation phenomenon: iodine 131-labelled fibrinogen. The isotopic exploration consists of a fibrinogen kinetics study combined with external counting over the kidney regions. The different stages of the procedure are described: separation, purification and labelling of fibrinogen; characteristics of the radioactive fibrinogen used; practical details of the examination itself; data analysis method. A chapter devoted to verifications and discussions of the procedure is followed by a report on the exploration of intrarenal coagulation phenomena in 30 kidney disease patients. In conclusion, the study of fibrinogen kinetics is considered as the most suitable method to detect local or slight intravascular coagulation phenomena. The sensitivity of the isotopic exploration is very satisfactory. The main criticism directed against this method is that the exploration is general and therefore blind [fr

Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Thompson, B.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Civil Engineering; Huff, D.D. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1997-05-01

In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative agreement between the USGS and the US Department of Energy (DOE), the data were made available to researchers at the Oak Ridge National Laboratory (ORNL), who organized the data into a data management format. The results of these groundwater tracer tests have been compiled into a collection of four SAS data sets. This report documents these SAS data sets, including their structure, methodology, and content. The SAS data sets include information on precipitation, tritium, water levels, and well construction for wells at or near ORNL radioactive waste burial grounds 4, 5, and 6.

Accumulation of radioactive iron in marine organisms

International Nuclear Information System (INIS)

Tateda, Yuzuru

1985-01-01

The accumulation and excretion of radioactive iron in some marine organisms was investigated by radio-tracer experiments. The concentration factor, biological half-life, distribution in body, and combining form in some organs, are compared and discussed between mollusks and fishes. The results obtained are: 1) The concentration factor of seaweed was higher than those of worm and fish in uptake from seawater. Abalone showed a higher concentration factor than fish. 2) The first component of excretion curve was small in case of a longer period of uptake from seawater. 3) Abalone and octopus showed a higher radioactivity retention than flounder and black-fish. 4) The fish fed labelled seaweed showed a lower radioactivity retention than fish fed labelled worm. 5) The fish fed radioisotopes with prey showed a higher radioactivity retention than fish fed labelled prey. 6) Biological half-lives were longer in abalone and octopus than in fishes. The biological half-lives of radioactive iron in fishes varied according to the uptake modes. 7) The distribution ratio of radioactive iron in organisms were large in the liver and degestive tract. 8) The GFC profile of 59 Fe in some organs of organisms showed combining form of same molecular weight of proteinous matter. (author)

Collection and processing of information in biological kinetics studies with radioactive tracers; Collecte et traitement de l'information dans les etudes de cinetique biologique avec traceurs radioactifs

Energy Technology Data Exchange (ETDEWEB)

Remy, J; Lafuma, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

The authors present an automatic method for the collection and treatment of information in biological kinetics experiments using radioactive tracers. The recording are made without any time constant on magnetic tape. The information recorded is sampled by a 400 channel multi-scale analyzer and transferred to punched cards. The digital analysis is done by an I.B.M. computer. The method is illustrated by an example: the hepatic fixation of colloidal gold in the pig. Its advantages and requirements are discussed. In the appendix are given the FORTRAN texts for two programmes used in treating the example presented. (authors) [French] Les auteurs presentent une methode automatique de collecte et de traitement de l'information dans les experiences de cinetique biologique utilisant les traceurs radioactifs. Les enregistrements sont realises sans constante de temps sur bande magnetique. L'information enregistree fait l'objet d'un echantillonnage a l'aide d'un analyseur a 400 canaux en mode multi-echelle puis est transferee sur cartes perforees. L'exploitation digitale est confiee a un ordinateur I.B.M.. La methode est illustree par un exemple d'etude de la fixation hepatique de l'or colloidal chez le porc. Ses avantages et ses exigences sont discutes. En annexe figurent les textes en FORTRAN de deux programmes utilises pour le traitement de l'exemple cite. (auteurs)

15N tracer kinetic studies on the validity of various 15N tracer substances for determining whole-body protein parameters in very small preterm infants

International Nuclear Information System (INIS)

Plath, C.; Heine, W.; Wutzke, K.D.; Krienke, L.; Toewe, J.M.; Massute, G.; Windischmann, C.

1987-01-01

Reliable 15 N tracer substances for tracer kinetic determination of whole-body protein parameters in very small preterm infants are still a matter of intensive research, especially after some doubts have been raised about the validity of [ 15 N]glycine, a commonly used 15 N tracer. Protein turnover, synthesis, breakdown, and further protein metabolism data were determined by a paired comparison in four preterm infants. Their post-conceptual age was 32.2 +/- 0.8 weeks, and their body weight was 1670 +/- 181 g. Tracer substances applied in this study were a [ 15 N]amino acid mixture (Ia) and [ 15 N]glycine (Ib). In a second group of three infants with a post conceptual age of 15 N-labeled 32.0 +/- 1.0 weeks and a body weight of 1,907 +/- 137 g, yeast protein hydrolysate (II) was used as a tracer substance. A three-pool model was employed for the analysis of the data. This model takes into account renal and fecal 15 N losses after a single 15 N pulse. Protein turnovers were as follows: 11.9 +/- 3.1 g kg-1 d-1 (Ia), 16.2 +/- 2.5 g kg-1 d-1 (Ib), and 10.8 +/- 3.0 g kg-1 d-1 (II). We were able to demonstrate an overestimation of the protein turnover when Ib was used. There was an expected correspondence in the results obtained from Ia and II. The 15 N-labeled yeast protein hydrolysate is a relatively cheap tracer that allows reliable determination of whole-body protein parameters in very small preterm infants

Subsonic aircraft soot. A tracer documenting barriers to inter-hemispheric mixing

Energy Technology Data Exchange (ETDEWEB)

Pueschel, R F [NASA Ames Research Center, Moffett Field, CA (United States)

1998-12-31

Meridional observations of soot aerosols and radioactive {sup 14}C, and models of the geographic distribution of nuclear bomb-released {sup 14}C and aircraft-emitted NO{sub x}, all show strong gradients between the hemispheres. Reason for it are decade-long inter-hemispheric mixing times which are much in excess of yearlong stratospheric residence times of tracers. Vertical mixing of soot aerosol is not corroborated by {sup 14}C observations. The reason could be radiometric forces that act on strongly absorbing soot. (author) 10 refs.

Subsonic aircraft soot. A tracer documenting barriers to inter-hemispheric mixing

Energy Technology Data Exchange (ETDEWEB)

Pueschel, R.F. [NASA Ames Research Center, Moffett Field, CA (United States)

1997-12-31

Meridional observations of soot aerosols and radioactive {sup 14}C, and models of the geographic distribution of nuclear bomb-released {sup 14}C and aircraft-emitted NO{sub x}, all show strong gradients between the hemispheres. Reason for it are decade-long inter-hemispheric mixing times which are much in excess of yearlong stratospheric residence times of tracers. Vertical mixing of soot aerosol is not corroborated by {sup 14}C observations. The reason could be radiometric forces that act on strongly absorbing soot. (author) 10 refs.

Rate tracer studies of heterogeneous catalysis

Energy Technology Data Exchange (ETDEWEB)

Happel, J; Kiang, S

1977-10-01

An analysis is presented of the extent to which parameters involved in transient tracing of isotopic species in heterogeneous catalysis can be determined by experiments in which tracer concentrations are measured as a function of time. Different treatments for open and closed systems with the over-all reaction at equilibrium or irreversible were developed.

Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas; Deteccion de fugas por radiotrazado en ducto marino para transporte de gas LP

Energy Technology Data Exchange (ETDEWEB)

Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e mail: efrp@nuclear.inin.mx

2008-07-01

In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO{sub 3}){sub 3} 6H{sub 2}O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

Dispersion of radioactive tracers (Energy transport in geological media)

International Nuclear Information System (INIS)

Moltyaner, G.L.; Wills, A.

1991-01-01

The idea of adding a gamma-emitting tracer like radioiodine to groundwater to measure its velocity offers a new approach to contaminant transport studies. In fact, the groundwater velocity is acquired by measuring, in situ, changes that the flowing water and sedimentary matrix jointly impose on the electromagnetic field generated by radioiodine. The information is encoded in the measured field intensity and it is transmitted continuously from the source to a radiation detector by electromagnetic energy photons. In situ sensed data acquired by scanning dry boreholes provide information on joint variations of static (sedimentary matrix) and dynamic (flowing water) elements of the aquifer over its depth. The spatial structure of the aquifer heterogeneities may be modelled in terms of the space-correlation coefficient between two velocities at two points a specified distance apart. This gives a new method for defining aquifer heterogeneities by the introduction of kinematically significant length scales of velocity variation without invoking Darcy's law and the concept of hydraulic conductivity. The dimensions of aquifer heterogeneities are defined in a longitudinal sense, along the mean flow direction, and in a transverse sense, in the transverse to flow direction. Two hierarchical scales of motion, local and integral, are introduced to characterize the mixing process caused by aquifer heterogeneity and depositional heterogeneity, respectively. At the microscopic and local scales, transport processes are characterized by the three-dimensional diffusion equation with, generally speaking, variable coefficients. At the integral scale, aquifer heterogeneities impose conditions on the transport such that for shallow aquifers the transport may be modelled by the dispersion equation with constant coefficients in one longitudinal dimension. 3 figs., 25 refs

New method for the radioactive determination of vitamin B12

International Nuclear Information System (INIS)

Lewin, Nathan; Fries, J.E.; Richards, C.S.

1975-01-01

A description is given of a method for the radioactive determination of vitamin B12 in a sample solution of serum in which a radioactive tracer of vitamin B12 and the vitamin B12 of the serum compete with respect to an intrinsic factor of limited linking capacity. The free radioactive vitamin B12 and the free vitamin B12 of the serum are separated from the intrinsic factor and from the radioactive vitamin B12 and from the serum vitamin B12 linked to this factor, before the radioactivity is measured against standard values. The method consists in separating the free radioactive vitamin B12 and the free serum vitamin B12 of the intrinsic factor and portions of radioactive and serum vitamin B12 linked to this factor, by adding an adequate quantity of bentonite to adsorb the free radioactive vitamin B12 and free serum vitamin B12 so that the intrinsic factor surface floating solution in association with the linked radioactive vitamin B12 and the linked serum vitamin B12 may be physically isolated from the solid bentonite that has adsorbed the free radioactive vitamin B12 and the free serum vitamin B12 [fr

Bed load determination in Parana river by radioactive tracer technique

International Nuclear Information System (INIS)

Aoki, P.E.; Enokihara, C.T.; Rocca, H.C.C.; Bittencourt, A.V.L.

1988-10-01

Radioactive tracing technique with marked sand was employed to evaluate the bottom sediment drag of Parana river, near the future site for the ''Ilha Grande'' Dam in Guaira City (State of Parana). 198 Au radioisotope was employed and measurements had been performed for a period of fifteen days. A bed load rate of 952,3 t/day was obtained for a laminar layer of 0,33 m mean thickness and 1.65 m/day mean velocity. (author) [pt

Fluctuation theorem for an optically trapped tracer in dense colloids. A simulation study

Directory of Open Access Journals (Sweden)

Puertas Antonio M.

2013-03-01

Full Text Available The work supplied by an external parabolic potential that traps one tracer in a colloidal system is studied in this work by computer simulations. The density of the bath is changed from zero up to values close to the glass transition, and the velocity varies over several decades from the linear behaviour in the low Peclet limit to the high Peclet limit. The work distributions are analyzed using the model for the isolated Brownian partice, where the friction coefficient and temperature of the medium have been fitted to reproduce the position distribution of the tracer in the trap. The overall agreement is good but not perfect. The region of negative works is studied in more detail using the predictions of the fluctuation theorem, finding good qualitative agreement with the model of the isolated Brownian particle. The present results indicate that the fluctuation theorem is of application in cases where the tracer dynamics is complex, as predicted by theoretical works.

Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

International Nuclear Information System (INIS)

Stetzenbach, K.; Farnham, I.

1996-01-01

Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test

Identification and characterization of conservative organic tracers for use as hydrologic tracers for the Yucca Mountain site characterization study. Final report

Energy Technology Data Exchange (ETDEWEB)

Stetzenbach, K.; Farnham, I.

1996-06-01

Extensive tracer testing is expected to take place at the C-well complex in the Nevada Test Site as part of the Yucca Mountain Site Characterization Project. The C-well complex consists of one pumping well, C3, and two injection wells, C1 and C2 into which tracer will be introduced. The goal of this research was to provide USGS with numerous tracers to completed these tests. Several classes of fluorinated organic acids have been evaluated. These include numerous isomers of fluorinated benzoic acids, cinnamic acids, and salicylic acids. Also several derivatives of 2-hydroxy nicotinic acid (pyridone) have been tested. The stability of these compounds was determined using batch and column tests. Ames testing (mutagenicity/carcinogenicity) was conducted on the fluorinated benzoic acids and a literature review of toxicity of the fluorobenzoates and three perfluoro aliphatic acids was prepared. Solubilities were measured and method development work was performed to optimize the detection of these compounds. A Quality Assurance (QA) Program was developed under existing DOE and USGS guidelines. The program includes QA procedures and technical standard operating procedures. A tracer test, using sodium iodide, was performed at the C-well complex. HRC chemists performed analyses on site, to provide real time data for the USGS hydrologists and in the laboratories at UNLV. Over 2,500 analyses were performed. This report provides the results of the laboratory experiments and literature reviews used to evaluate the potential tracers and reports on the results of the iodide C-well tracer test.

Application of organic tracers in characterizing the greater confinement disposal test at the Nevada Test Site

International Nuclear Information System (INIS)

Olson, M.C.

1985-01-01

The Greater Confinement Disposal Test (GCDT) is a research project investigating the feasibility of augered-shaft disposal of low-level radioactive waste considered unsuitable for shallow land burial. Gaseous diffusion of radionuclides through alluvial sediments is considered the primary contaminant migration process. Volatile halocarbon tracers are released in the subsurface and their migration is monitored to determine media effective diffusion coefficients, tortuosity values, and sorption terms. Design and instrumentation of the emplacement and monitoring shafts of the disposal facility are detailed. Instrumentation includes a three-dimensional array of soil-air sample stations encircling the disposal waste. Recirculation flow lines minimize induced advection in the alluvial matrix due to tracer sample collection. 6 references, 5 figures, 2 tables

Natural tracer profiles across argillaceous formations: the Claytrac project

International Nuclear Information System (INIS)

Mazurek, M.; Alt-Epping, P.; Gimi, Th.; Niklaus Waber, H.; Bath, A.; Gimmi, Th.

2009-01-01

Disposal of high-level radioactive waste and spent nuclear fuel in engineered facilities, or repositories, located deep underground in suitable geological formations is being developed worldwide as the reference solution to protect humans and the environment both now and in the future. An important aspect of assessing the long-term safety of deep geological disposal is developing a comprehensive understanding of the geological environment in order to define the initial conditions for the disposal system as well as to provide a sound scientific basis for projecting its future evolution. The transport pathways and mechanisms by which contaminants could migrate in the surrounding host rock are key elements in any safety case. Relevant experiments in laboratories or underground test facilities can provide important information, but the challenge remains in being able to extrapolate the results to the spatial and temporal scales required for performance assessment, which are typically tens to hundreds of metres and from thousands to beyond a million years into the future. Profiles of natural tracers dissolved in pore water of argillaceous rock formations can be considered as large-scale and long-term natural experiments which enable the transport properties to be characterised. The CLAYTRAC Project on Natural Tracer Profiles Across Argillaceous Formations was established by the NEA Clay Club to evaluate the relevance of natural tracer data in understanding past geological evolution and in confirming dominant transport processes. Data were analysed for nine sites to support scientific understanding and development of geological disposal. The outcomes of the project show that, for the sites and clay-rich formations that were studied, there is strong evidence that solute transport is controlled mainly by diffusion. The results can improve site understanding and performance assessment in the context of deep geological disposal and have the potential to be applied to other

Contribution of natural tracers for understanding transfers through argillaceous formations

International Nuclear Information System (INIS)

Bensenouci, F.

2010-01-01

This study is part of a research programme conducted by IRSN on the safety of deep geological disposal of high level and intermediate long-lived radioactive wastes. It more especially concerns the geological medium considered as a full component of the multi-barrier concept proposed by Andra for a deep repository. Indeed, the Callovo-Oxfordian argillite of the Paris Basin, in the east of France, is being investigated by Andra as a potential host rock for this repository. Performance assessment of this natural barrier is based on the knowledge of its confinement properties and therefore on phenomena possibly involved in the mass transport of radionuclides. In this context, this work aimed at studying the distribution of tracers naturally present in pore waters obtained from boreholes having crossed Mesozoic sedimentary series involving impervious and compacted clay rocks in the East (Andra borehole, EST433) and south of France (IRSN boreholes). Radial diffusion and vapour exchange methods were used to calculate the concentrations and diffusion parameters of the studied tracers. In Tournemire formations, the different profiles describe a curved shapes attributed to a diffusive exchange between the argillite pore water and the surrounding aquifers. Concerning the Mesozoic formations crossed by EST433, the study of the different profiles confirms the diffusion as the dominant transport mechanism in the Callovo-Oxfordian formation, and permits identifying the transport processes in the whole studied column from the Oxfordian formations down to the Liassic one. This study also helps to identify the Liassic formations as a major source of salinity of the Dogger aquifer

Isotope and chemical tracers in groundwater hydrology

International Nuclear Information System (INIS)

Kendall, C.; Stewart, M.K.; Morgenstern, U.; Trompetter, V.

1999-01-01

The course sessions cover: session 1, Fundamentals of stable and radioactive isotopes; session 2, Stable oxygen and hydrogen isotopes in hydrology: background, examples, sampling strategy; session 3, Catchment studies using oxygen and hydrogen isotopes: background - the hydrologic water balance, evapotranspiration - the lion's share, runoff generation - new water/old water fractions, groundwater recharge - the crumbs; session 4, Isotopes in catchment hydrology: survey of applications, future developments; session 5, Applications of tritium in hydrology: background and measurement, interpretation, examples; session 6, Case studies using mixing models: Hutt Valley groundwater system, an extended mixing model for simulating tracer transport in the unsaturated zone; session 7, Groundwater dating using CFC concentrations: background, sampling and measurement, use and applications; session 8, Groundwater dating with carbon-14: background, sampling and measurement, use and applications; session 9, NZ case studies: Tauranga warm springs, North Canterbury Plains groundwater; session 10, Stable carbon and nitrogen isotopes: background and examples, biological applications of C-N-S isotopes; session 11, New developments in isotope hydrology: gas isotopes, compound specific applications, age dating of sediments etc; session 12, NZ case studies: North Canterbury Plains groundwater (continued), Waimea Plains groundwater. (author). refs., figs

Characterization of crushed tuff for the evaluation of the fate of tracers in transport studies in the unsaturated zone

International Nuclear Information System (INIS)

Polzer, W.L.; Fuentes, H.R.; Raymond, R.; Bish, D.L.; Gladney, E.S.; Lopez, E.A.

1987-03-01

Results of field-scale (caisson) transport studies under unsaturated moisture and steady and nonsteady flow conditions indicate variability and a lack of conservation of mass in solute transport. The tuff materials used in that study were analyzed for the presence of tracers and of freshly precipitated material to help explain the variability and lack of conservation of mass. Selected tuff samples were characterized by neutron activation analysis for tracer identification, by x-ray diffraction for mineral identification, by petrographic analysis for identification of freshly precipitated material, and by x-ray fluorescence analysis for identification of major and trace elements. The results of these analyses indicate no obvious presence of freshly precipitated material that would retard tracer movement. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of the nonsorbing tracers (bromide and iodide) suggest the retention of these tracers in immobile water. The presence of sorbing and nonsorbing tracers on the tuff at some locations (even cesium at the 415-cm depth) and not at others suggests variability in transport. 15 refs., 14 figs., 9 tabs

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

1993 Annual progress report for subsidiary agreement No. 2 (1991--1996) between AECL and US/DOE for a radioactive waste management technical co-operative program

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-12-31

A coordinated research program on radioactive waste disposal is being carried out by the Atomic Energy of Canada Limited and the US Department of Energy. This annual report describes progress in the following eight studies: Fundamental materials investigations; In-situ stress determination; Development of a spent fuel dissolution model; Large block tracer test--Experimental testing of retardation models; Laboratory and field tests of in-situ hydrochemical tools; Cigar Lake--Analogue study, actinide and fission product geochemistry; Performance assessment technology exchange; and Development of multiple-well hydraulic test and field tracer test methods.

1993 Annual progress report for subsidiary agreement No. 2 (1991--1996) between AECL and US/DOE for a radioactive waste management technical co-operative program

International Nuclear Information System (INIS)

1993-01-01

A coordinated research program on radioactive waste disposal is being carried out by the Atomic Energy of Canada Limited and the US Department of Energy. This annual report describes progress in the following eight studies: Fundamental materials investigations; In-situ stress determination; Development of a spent fuel dissolution model; Large block tracer test--Experimental testing of retardation models; Laboratory and field tests of in-situ hydrochemical tools; Cigar Lake--Analogue study, actinide and fission product geochemistry; Performance assessment technology exchange; and Development of multiple-well hydraulic test and field tracer test methods

Studies of 15N transamination following application of various tracer substances. 1

International Nuclear Information System (INIS)

Schadereit, R.; Krawielitzki, K.; Herrmann, U.

1986-01-01

4 groups of 3 growing Wistar rats each were orally given 15 N-labelled methionine, lysine, glycine and ammonia sulphate, resp., over 10 days. Measuring the 15 N accumulation in the amino acids (AA) of the body protein, the transamination of the individual 15 N substances and thus their suitability as tracer substances for studies of N metabolism was determined. None of the tested 15 N-AA achieved a proportionate labelling of all AA of the body protein. The AA used as tracer in each case showed the highest 15 N labelling. Of the amino- 15 N detected in the animal body, about 19% were found in Met after 15 N Met application, 88% in Lys after 15 N Lys application and 50% in Gly after 15 N Gly application. After the application of 15 N-ammonia sulphate about 42% of the body amino- 15 N are apportioned to the essential and 58% to the non-essential AA. Thus, this substance produces a more proportional labelling of the essential and non-essential AA of the body protein than 15 N-Gly. The following quotas of the 15 N amounts applied were found in the AA of the animal bodies: tracer substance lysine 52%, glycine 32%, ammonia sulphate 24%, methionine 21%. After summing up the amino acid 15 N amounts in the animal body, eliminating in each case the tracer AA and taking into account the molecular weight of the AA, there was a good agreement of the intensity of the accumulation of 15 N in the individual AA, irrespective of the applied tracer substance. (author)

First technical report about tracer applications to processes assessment in a portable water potabilizing plant

International Nuclear Information System (INIS)

Suarez Antola, R.; Giosa Porley, P.

1996-03-01

Radioactive and fluorescent tracers were applied to measure the distribution of residence times in each of the four subsystems of a portable water purifying plant: the mechanical flocculation unit, the hydraulic flocculation unit, the sedimentation unit, and the sand filter. This report begins by a revision of the physicochemical processes produced in each of the above mentioned subsystems, connected in series. Then a mathematical model of residence time distribution for each unit is constructed, with free parameters that can be estimated from the experimental results obtained with tracers. Tracer methodology for this kind of field experiment is reviewed. Their possible short comes are briefly discussed for each of the intended tracers. The tracer experiments done with rhodamine and uranine are described. The experimental results are reported and the residence time distributions obtained with different tracers were carefully compared. In order to make the field experiments, five different values of global water flow were sustained, pumping in steady state: two under the nominal (design) value, two above the design flow and one equal to the nominal water flow. The model parameters were determined using a software package, D TR , made in France and supplied by the IAEA in the framework of the project. It was discovered that the diffuser in the sedimentation unit was not working as intended, and some guidelines for its re-design could be given to the process engineers. Also, process engineers received information about some amount of by-pass flow and death zones, as well as their variations with plant's global water flow

Radioactivity levels in surface water of lakes around Izmir / Turkey

International Nuclear Information System (INIS)

Doyurum, S.; Turkozu, D. A.; Aslani, M. A. A.; Aytas, S.; Eral, M.; Kaygun, A. K.

2006-01-01

Radioactivity presents in surface continental waters is mainly due to the presence of radioactive elements in the earth's crust, other artificial radionuclides have appeared due to such human activities as nuclear power plants, nuclear weapons testing and manufacture and use of radioactive sources It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements among dissolved and particulate phases in aquatic systems. The detection of high radionuclide concentrations was proposed as a public health problem in several areas and consequently studies into the risks of radionuclides were started in the 2000s. Especially, these radioactive substances in groundwater are an unwanted and involuntary risk factor from natural sources, not artificial sources. These radioactive substances include uranium, radon found in uranium series, and other radioactive substances such as radium and gross alpha. Uranium present in rock, soil, and natural materials, and is found in small quantities in air, water, and food that people always contact. In this project, lake water samples were collected from three lakes around Izmir-Turkey. In surface lake water samples, pH, mV and conductivity values were measured and alkaline content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. The radioactivity concentrations related to gross radium isotopes, gross-? and gross-? activities in the surface lake water were determined. The correlation among some parameters for water samples and concentrations of uranium, activity concentration of gross radium isotopes, gross alpha and gross beta radioactivity are also discussed

Hydraulic and tracer experiments in the TVO research tunnel 1993- 1994

International Nuclear Information System (INIS)

Hautojaervi, A.; Ilvonen, M.; Vieno, T.; Viitanen, P.

1995-04-01

Three full-size deposition holes (diameter 1.5 m, depth 7.5 m) for spent fuel canisters in a KBS-3 type repository have been bored with a new fullface boring method in the TVO Research Tunnel. The Research Tunnel lies in the crystalline bedrock at the depth of 60 metres in the VLJ Repository for low and medium level waste. The holes are 6 metres apart. The boring tests were accompanied by comprehensive pre- and post-characterization of the rock and the bored wells. The inflow rates of groundwater in two of the three full-size holes are 6 and 20 litres/hour. The well in the middle is almost dry as expected on the basis of the pre-characterization. In the tracer tests two different tracers, a dye and a radioactive tracer, were used at the same time. The comprehensive data analysis performed showed that novel techniques (e.g. Extreme Value Estimation, EVE) can be successfully applied to determine the impulse response from the experimental results even in cases where the measured signals are disturbed. Hydraulic and tracer tests as well as visual inspection of the inflow gave clear indications of flow and transport in sparse and narrow channels. Transport velocities could be predicted with a reasonable accuracy by using a simple concept of fracture cavities determining the transport time and 'bottlenecks' causing the hydraulic resistance. The observed non-Fickian dispersion is thought to be caused by velocity differences over the channel width or by diffusion into stagnant pools in the fracture filling. (orig.) (36 refs., 67 figs., 1 tab.)

Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations

International Nuclear Information System (INIS)

Helfer, Andreas

2013-01-01

With the growing importance of positron emission tomography (PET) for in vivo imaging in diagnostic medicine there is great interest of developing new labelling methods for the positron emitter selenium-73. As attractive application an examination of a no-carrier-added (n.c.a.) preparation of the analogous tracer Sulindac Selenid and of the selenium containing compound Ebselen was examined with 73,75 Se. First of all a labelling strategy for Sulindac Selenid based on a protected precursor was developed. This precursor should further be transformed into the corresponding standard compound for chomatographic identification of the n.c.a. product. This, however, was not possible. An alternative synthesis method also did not result in a product. Thus, a radioactive labelling in case of Sulindac Selenid was not indicated in spite of a successful synthesis of a precursor. The preparation of Ebselen was performed as earlier described by a sequential one-pot synthesis with a yield of 46 %. An adaption of the reaction parameters to a radiosynthesis with 75 Se failed on the n.c.a. state and also after adding carrier to the reaction mixture. The desired product could, however, be prepared in a copper catalysed one-pot radiosynthesis for the first time under carrier-added conditions. Here, optimized conditions resulted in radiochemical yields of 60 ± 18 %. A no-carrier-added product could finally be achieved using sulphur as nonisotopic carrier in the reaction mixture. After optimisation of reaction parameters n.c.a. [ 75 Se]Ebselen could be synthesized with radiochemical yields of 55 ± 7 % within 4 h. Furthermore the desired product could be separated by RHPL-chromatography from its co-produced sulfur-analogue. After transferring the conditions to radiosyntheses with the positron emitter 73 Se, n.c.a. [ 73 Se]Ebselen could be achieved with a radiochemical yield of 22 ± 1 % and can now be used as a potential radiotracer in preclinical evaluation studies with respect to

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.

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.

Final report of the TRUE Block Scale project. 2. Tracer tests in the block scale

Energy Technology Data Exchange (ETDEWEB)

Andersson, Peter; Byegaard, Johan [Geosigma AB, Uppsala (Sweden); Winberg, Anders [Conterra AB, Partille (Sweden)

2002-05-01

The tracer test programme of the TRUE Block Scale Project involved 14 tracer tests campaigns, including performance of 32 tracer injections in 16 different combinations of source and sink sections (flow paths) varying in length between 10 to 130 metres, and involving one or more structures. Average, travel times varied between 1.5 and >2000 hours. Tracer dilution tests performed in conjunction with cross-hole hydraulic pumping tests were found to be a very important part of the pre-tests, where the results were used to identify and screen among possible injection points, and to verify the hydrostructural model valid at a given time. The main problem faced in the block scale tests was to select a test geometry, which gave a sufficiently high mass recovery, and at the same time enabled performance of cross-hole sorbing tracer tests within reasonable time frames. Three different injection methods were applied during the test programme; decaying pulse, finite pulse and forced pulse (unequal dipole). During the later phases of the tracer test programme it was identified that forced injection had to be employed in order to enable detection of tracer at the sink due to strong dilution, and also to avoid problems with artificially induced tailing in the injection signal. Sorbing (reactive) tracers were selected among the radioactive isotopes of the alkali and alkaline earth metals previously used in the TRUE- 1 experiments. It was decided that at least one slightly sorbing tracer and one strongly sorbing tracer should be used in each injection. Non-sorbing tracers were used for conservative reference, e.g., {sup 82}Br{sup -}, {sup 186}ReO{sub 4}, HTO (tritiated water) and {sup 131}I{sup -}. In two of the injections the radioactive non-sorbing tracers were rather short-lived and Uranine and Naphthionate were used as complementary conservative tracers. Surface distribution coefficients, K{sub a}, were evaluated from TRUE-1 and TRUE Block Scale data, making use of the

Final report of the TRUE Block Scale project. 2. Tracer tests in the block scale

International Nuclear Information System (INIS)

Andersson, Peter; Byegaard, Johan; Winberg, Anders

2002-05-01

The tracer test programme of the TRUE Block Scale Project involved 14 tracer tests campaigns, including performance of 32 tracer injections in 16 different combinations of source and sink sections (flow paths) varying in length between 10 to 130 metres, and involving one or more structures. Average, travel times varied between 1.5 and >2000 hours. Tracer dilution tests performed in conjunction with cross-hole hydraulic pumping tests were found to be a very important part of the pre-tests, where the results were used to identify and screen among possible injection points, and to verify the hydrostructural model valid at a given time. The main problem faced in the block scale tests was to select a test geometry, which gave a sufficiently high mass recovery, and at the same time enabled performance of cross-hole sorbing tracer tests within reasonable time frames. Three different injection methods were applied during the test programme; decaying pulse, finite pulse and forced pulse (unequal dipole). During the later phases of the tracer test programme it was identified that forced injection had to be employed in order to enable detection of tracer at the sink due to strong dilution, and also to avoid problems with artificially induced tailing in the injection signal. Sorbing (reactive) tracers were selected among the radioactive isotopes of the alkali and alkaline earth metals previously used in the TRUE- 1 experiments. It was decided that at least one slightly sorbing tracer and one strongly sorbing tracer should be used in each injection. Non-sorbing tracers were used for conservative reference, e.g., 82 Br - , 186 ReO 4 , HTO (tritiated water) and 131 I - . In two of the injections the radioactive non-sorbing tracers were rather short-lived and Uranine and Naphthionate were used as complementary conservative tracers. Surface distribution coefficients, K a , were evaluated from TRUE-1 and TRUE Block Scale data, making use of the retardation noted in the injection

Atmospheric tracer experiments for regional dispersion studies

International Nuclear Information System (INIS)

Heffter, J.L.; Ferber, G.J.

1980-01-01

Tracer experiments are being conducted to verify atmospheric transport and dispersion calculations at distances from tens to hundreds of km from pollutant sources. In one study, a 2 1/2 year sampling program has been carried out at 13 sites located 30 to 140 km from a source of 85 Kr at the Savannah River Plant in South Carolina. Average weekly concentrations as well as twice-daily concentrations were obtained. Sampling data and meteorological data, including surface, tower, and rawinsonde observations are available on magnetic tape for model verification studies. Some verification results for the Air Resources Laboratories Atmospheric Transort and Dispersion Model (ARL-ATAD) are shown for averaging periods from one week to two years

The data analysis of the single well injection-withdraw tracer experiment using the MACRO II

International Nuclear Information System (INIS)

Shirakawa, Toshihiko; Kanazawa, Yasuo; Hatanaka, Koichiro

2001-04-01

On understanding the radionuclide transport in natural barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, we have conducted lots of tracer experiments by the MACRO II facility with an artificially constructed heterogeneous permeability field. In order to study the scale dependence of dispersion coefficients in case of laboratory experiments, we placed the flow cell horizontally, and conducted injection-withdraw tracer experiment with a single well. We have conducted 15 cases experiments. These cases were prepared by changing a position of single well and the injection-withdraw time. At each position we have conducted 9 cases and 6 cases experiments. In this report, we evaluated the macroscopic dispersion coefficients by the fitting of analytical solution to breakthrough curve measured by the 15 cases pumping tracer experiment. Consequently, we could evaluate the dispersion coefficients for 12 cases of 15 cases. Then, we discussed the relation between a injection-withdraw flow rate and a property of heterogeneous media and dispersion coefficient. The conclusions obtained from the results of the evaluation are summarized as follows, It was found that the macroscopic dispersion coefficients tend to be increased with increase of the average radius of tracer front spread around a single well. We have conducted any experiments with s single well settled at two positions. In case of that there is low permeability around a single well, we found dispersion coefficients are large. In case of that there is high permeability around a single well, we found dispersion coefficients are small. In three cases that we could not evaluate because of incorrect accuracy of fitting, we have found it possible that there is some points that dispersion coefficients were strikingly small in tracer front. (author)

Contribution to the selection of radioactive tracers for hydrogeology; Contribution a la selection de traceurs radioactifs pour l'hydrogeologie

Energy Technology Data Exchange (ETDEWEB)

Lallemand, A [Bureau de recherches geologiques et minieres (BRGM), Paris (France); Grison, G [Commission des Communautes europeennes, Brussels (Belgium)

1970-09-15

A systematic study was made of a number of anionic and cationic tracers in different terrains with distinct petrographic characteristics, allowance being made for the various physical and chemical parameters of the environment. The behaviour of 12 tracers ({sup 51}Cr, {sup 59}Fe, {sup 45}Ca, {sup 110}Ag, {sup 24}Na, {sup 137}Cs, {sup 3}H, {sup 32}P, {sup 35}S, {sup 14}C, {sup 131}I, {sup 82}Br) was studied in six types of argillaceous rock (illite, vermiculite, interstratified illite-vermiculite, montmorillonite, attapulgite and kaolinite) and three sand types (siliceous, calcareous and dolomitic) in the presence of three types of water (demineralized, sea-water and various spring waters). On the basis of the results obtained from 5000 tests and measurements made during this study it is possible to select the tracer most suited to the characteristics of the terrain and the type of groundwater. (author) [French] Les travaux effectues ont pour objectif l'etude systematique d'un certain nombre de traceurs anioniques et cationiques sur une serie de terrains a caracteristiques petrographiques bien determinees, compte tenu d'un certain nombre de parametres physiques et chimiques du milieu. Le comportement de douze traceurs ({sup 51}Cr, {sup 59}Fe, {sup 45}Ca, {sup 110}Ag, {sup 24}Na, {sup 137}Cs, {sup 3}H, {sup 32}P, {sup 35}S, {sup 14}C, {sup 131}I et {sup 82}Br) a ete etudie dans six roches argileuses (illite, vermiculite, interstratifie illite-vermiculite, montmorillonite, attapulgite, kaolinite) et trois sables (siliceux, calcaire, dolomitique) en presence de trois types d'eau (demineralisee, eau de mer et diverses eaux de source). Les resultats des 5000 essais et mesures effectues au cours de cette etude permettent de selectionner le traceur repondant le mieux aux caracteristiques du terrain et du type d'eau de la nappe. (author)

Contribution to the Selection of Radioactive Tracers for Hydrogeology; Contribution a la Selection de Traceurs Radioactifs pour l'Hydrogeologie

Energy Technology Data Exchange (ETDEWEB)

Lallemand, Andree [Bureau de Recherches Geologiques et Minieres (BRGM), Paris (France); Grison, G. [Commission des Communautes Europeennes, Bruxelles (Belgium)

1970-09-15

A systematic study was made of a number of anionic and cationic tracers in different terrains with distinct petrographic characteristics, allowance being made for the various physical and chemical parameters of the environment. The behaviour of 12 tracers ({sup 51}Cr, {sup 59}Fe, {sup 45}Ca, {sup 110}Ag, {sup 24}Na, {sup 137}Cs, {sup 3}H, {sup 32}P, {sup 35}S, {sup 14}C, {sup 131}I, {sup 82}Br) was studied in six types of argillaceous rock (illite, vermiculite, interstratified illite-vermiculite, montmorillonite, attapulgite and kaolinite) and three sand types (siliceous, calcareous and dolomitic) in the presence of three types of water (demineralized, sea-water and various spring waters). On the basis of the results obtained from 5000 tests and measurements made during this study it is possible to select the tracer most suited to the characteristics of the terrain and the type of groundwater. (author) [French] Les travaux effectues ont pour objectif l'etude systematique d'un certain nombre de traceurs anioniques et cationiques sur une serie de terrains a caracteristiques petrographiques bien determinees, compte tenu d'un certain nombre de parametres physiques et- chimiques du milieu. Le comportement de douze traceurs ({sup 51}Cr, {sup 59}Fe, {sup 45}Ca, {sup 110}Ag, {sup 24}Na, {sup 137}Cs, {sup 3}H, {sup 32}P, {sup 35}S, {sup 14}C, {sup 131}I et {sup 82}Br) a ete etudie dans six roches argileuses (illite, vermiculite, interstratifie illite-vermiculite, montmorillonite, attapulgite, kaolinite) et trois sables (siliceux, calcaire, dolomitique) en presence de trois types d'eau (demineralisee, eau de mer et diverses eaux de source). Les resultats des 5000 essais et mesures effectues au cours de cette etude permettent de selectionner le traceur repondant le mieux aux caracteristiques du terrain et du type d'eau de la nappe. (author)

The transport of zinc and manganese tracers across the Magela Creek system, Northern Territory

International Nuclear Information System (INIS)

Airey, P.L.; Calf, G.E.; Davison, A.; Easey, J.F.; Morley, A.

1983-01-01

A study has been made of the transport of 54 Mn and 65 Zn released into Magela Creek near Jabiru and into the Leichhardt Billabong on the Magela Plains. Near Jabiru, both isotopes were systematically removed from the surface water by adsorption on the bottom sediments. The 54 Mn was preferentially removed initially; the 65 Zn adsorption became relatively more significant further downstream. Systematic differences are thought to reflect the time-dependent evolution of the species distribution in fresh water systems. The heavy metal tracers injected into the Leichhardt Billabong were non-selectively removed by the vegetation as the radioactive plume crossed onto the shallow flood plain

Axillary sentinel node identification in breast cancer patients: degree of radioactivity present at biopsy is critical

DEFF Research Database (Denmark)

Nielsen, Kristina R; Oturai, Peter S; Friis, Esbern

2011-01-01

The radioactivity present in the patient (Act(rem) ) at sentinel node (SN) biopsy will depend on injected activity amount as well as on the time interval from tracer injection to biopsy, which both show great variations in the literature. The purpose of this study was to analyse the influence...... of varying Act(rem) levels on the outcome of axillary SN biopsy in patients with breast cancer (BC)....

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

Modelling and tracer studies of atmospheric dispersion and deposition in regions of complex topography

International Nuclear Information System (INIS)

Norden, C.E.

1981-11-01

An indium tracer aerosol generating apparatus based on an alcohol/oxygen burner, and an analytical procedure by which filter samples containing tracer material could be analysed quantitatively by means of neutron activation analysis, were developed for use in atmospheric dispersion and deposition studies. A number of series of atmospheric dispersion experiments were conducted in the Richards Bay and Koeberg- Cape Town areas. The results are given, comparing the airbone tracer concentrations measured at ground level with values predicted by means of a numerical model, utilising two to three schemes, varying in sophistication, for calculating the dispersion coefficients. Recommendations are given regarding a dispersion model and dispersion coefficients for regular use in the Koeberg area, and ways for estimating plume trajectories

Evaluation of the radionuclide tracer test conducted at the project Gnome Underground Nuclear Test Site, New Mexico

International Nuclear Information System (INIS)

Pohll, G.; Pohlmann, K.

1996-08-01

A radionuclide tracer test was conducted in 1963 by the U.S. Geological Survey at the Project Gnome underground nuclear test site, approximately 40 km southeast of Carlsbad, New Mexico. The tracer study was carried out under the auspices of the U.S. Atomic Energy Commission (AEC) to study the transport behavior of radionuclides in fractured rock aquifers. The Culebra Dolomite was chosen for the test because it was considered to be a reasonable analogue of the fractured carbonate aquifer at the Nevada Test Site (NTS), the principal location of U.S. underground nuclear tests. Project Gnome was one of a small number of underground nuclear tests conducted by the AEC at sites distant from the NTS. The Gnome device was detonated on December 10, 1961 in an evaporate unit at a depth of 360 m below ground surface. Recently, the U.S. Department of Energy (DOE) implemented an environmental restoration program to characterize, remediate, and close these offsite nuclear test areas. An early step in this process is performance of a preliminary risk analysis of the hazard posed by each site. The Desert Research Institute has performed preliminary hydrologic risk evaluations for the groundwater transport pathway at Gnome. That evaluation included the radioactive tracer test as a possible source because the test introduced radionuclides directly into the Culebra Dolomite, which is the only aquifer at the site. This report presents a preliminary evaluation of the radionuclide tracer test as a source for radionuclide migration in the Culebra Dolomite. The results of this study will assist in planning site characterization activities and refining estimates of the radionuclide source for comprehensive models of groundwater transport st the Gnome site

Radioactive background with thymine dimer estimation in uv irradiated Escherichia coli cells

Energy Technology Data Exchange (ETDEWEB)

Masek, F [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Vyskumny Ustav Onkologicky

1976-01-01

Ultraviolet radiation induces photoproducts in the cell DNA, mainly pyrimidine dimers responsible for the essential part of lethal and mutagenic damage. Radioactive tracers were used in determining the amount of photoproducts. Radioisotope labelling of microbial cells involves the problem of background which influences analytical results. Undesirably high radioactive background on the chromatograms of the hydrolysates of the acid-insoluble fraction of UV irradiated Escherichia coli cells complicates the determination of the amount of UV photoproducts. The background may be suppressed by chromatographic purification of radioactive precursors. Also a more thorough separation orocedure of DNA macromolecules contributes to reducing the background. From this point of view it seems advantageous to use two-dimensional paper chromatography rather than one-dimensional.

Choice of infusion-sampling mode for tracer studies of free fatty acid metabolism

International Nuclear Information System (INIS)

Jensen, M.D.; Rogers, P.J.; Ellman, M.G.; Miles, J.M.

1988-01-01

To determine the preferred infusion-sampling mode for isotopic studies of free fatty acid (FFA) metabolism, tracer [( 14 C]palmitate) was infused into the left ventricle of five anesthetized dogs, and tracee ([ 3 H]palmitate) was infused into three separate peripheral veins of each dog. The [ 14 C]palmitate specific activity (SA) was lower in mixed venous than arterial blood, and [ 3 H]palmitate SA was equal in both sites. The actual infusion rate of [ 3 H]palmitate [2.15 +/- 0.31 X 10(5) disintegrations/min (dpm).kg-1.min-1] could be accurately predicted (2.14 +/- 0.32 X 10(5) dpm.kg-1.min-1) using the known [ 14 C]palmitate infusion rate and the arterial plasma [ 14 C]-to-[ 3 H]palmitate ratio. In contrast, the mixed venous [ 14 C]-to-[ 3 H]palmitate ratio resulted in overestimates (P less than 0.05) of the actual [ 3 H]palmitate infusion rate. In summary, venous tracer infusion with arterial blood sampling for FFA tracer studies provides the most accurate estimates of tracee rate of appearance

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.

Radon as a natural tracer for gas transport within uranium waste rock piles

International Nuclear Information System (INIS)

Silva, N.C.; Chagas, E.G.L.; Dias, D.C.S.; Guerreiro, E.T.Z.; Alberti, H.L.C.; Braz, M.L.; Abreu, C.B.; Lopez, D.; Branco, O.; Fleming, P.

2014-01-01

Acid mine drainage (AMD) has been identified as the main cause for outflow of acid water and radioactive/non-radioactive contaminants. AMD encompasses pyrites oxidation when water and oxygen are available. AMD was identified in uranium waste rock piles (WRPs) of Industrias Nucleares do Brasil-Caldas facility (Brazilian uranium mine), resulting in high costs for water treatment. AMD reduction is the main challenge, and scientific investigation has been conducted to understand oxygen and water transportation within WRPs, where 222 Rn is used as natural tracer for oxygen transportation. The study consists of soil radon gas mapping in the top layer of WRP4 using active soil gas pumping, radon adsorption in active charcoal and 222 Rn determination using high-resolution gamma-ray spectrometry. A sampling network of 71 points was built where samples were collected at a depth of 40 cm. Soil radon gas concentration ranged from 33.7 to 1484.2 kBq m -3 with mean concentration of 320.7±263.3 kBq m -3 . (authors)

Heterogeneous distribution of a diffusional tracer in the aortic wall of normal and atherosclerotic rabbits

International Nuclear Information System (INIS)

Tsutsui, H.; Tomoike, H.; Nakamura, M.

1990-01-01

Tracer distribution as an index of nutritional support across the thoracic and abdominal aortas in rabbits in the presence or absence of atherosclerotic lesions was evaluated using [ 14 C]antipyrine, a metabolically inert, diffusible indicator. Intimal plaques were produced by endothelial balloon denudation of the thoracic aorta and a 1% cholesterol diet. After a steady intravenous infusion of 200 microCi of [ 14 C]antipyrine for 60 seconds, thoracic and abdominal aortas and the heart were excised, and autoradiograms of 20-microns-thick sections were quantified, using microcomputer-aided densitometry. Regional radioactivity and regional diffusional support, as an index of nutritional flow estimated from the timed collections of arterial blood, was 367 and 421 nCi.g-1 (82 and 106 ml.min-1.100 g-1) in thoracic aortic media of the normal and atherosclerotic rabbits, respectively. Radioactivity at the thickened intima was 179 nCi.g-1 (p less than 0.01 versus media). The gruel was noted at a deeper site within the thickened intima, and diffusional support here was 110 nCi.g-1 (p less than 0.01 versus an average radioactivity at the thickened intima). After ligating the intercostal arteries, regional tracer distribution in the media beneath the fibrofatty lesion, but not the plaque-free intima, was reduced to 46%. Thus, in the presence of advanced intimal thickening, the heterogeneous distribution of diffusional flow is prominent across the vessel wall, and abluminal routes are crucial to meet the increased demands of nutritional requirements

A 82Br tracer study of coastal groundwater movement at Hat Head, NSW

International Nuclear Information System (INIS)

Hughes, C.; Stone, D.

2003-01-01

At Hat Head, NSW, on the eastern Australian coast, a radioisotope tracer study of groundwater flow in response to tidal forcing was conducted adjacent to a tidal creek. Using radiotracer, 82 Br, groundwater movement was tracked in-situ over 5 days on two occasions encompassing both neap and spring tide conditions. The tracer was injected into one borehole and gamma counts monitored from an adjacent borehole using NaI(Th) detectors. This technique maps the path of the slow moving tracer without sampling and allows the net groundwater movement to be distinguished from short term tidally driven fluxes. During the neap tide period net groundwater movement of 0.1 m/d was observed with horizontal tidal fluctuations in the order of 0.04 m. This contrasts with the tidally dominated spring tide period where net groundwater movement was negligible but tidally driven fluctuations of up to 0.13 m were observed

Environmental assessment of the use of radionuclides as tracers in the enhanced recovery of oil and gas. Final report

International Nuclear Information System (INIS)

Ng, Y.C.; Cederwall, R.T.; Anspaugh, L.R.

1983-01-01

An environmental assessment of the use of radioisotopes as interwell tracers in field flooding for the enhanced recovery of oil and natural gas was performed. A typical operation using radioisotopes for interwell tracing was analyzed from the standpoint of three stages of operation: aboveground, subsurface, and recovery and disposal. Doses to workers who handle radioactive tracers and to members of the public were estimated for normal and accidental exposure scenarios. On the basis of estimates of the total quantity of tracer radionuclides injected in a year, the annual number of projects, the average number of injections per project, and assumed values of accident frequency, the collective dose equivalent is estimated to be 1.1 man-rem/y to workers and 15 man-rem/y to members of the public. The national radiological impact of the use of radioisotopes as interwell tracers in EOR projects is estimated to be a total collective dose equivalent of <16 man-rem/y. Accidential exposures are estimated to contribute relatively little to the total. 47 references, 8 figures, 43 tables

In-situ tracer tests and models developed to understand flow paths in a shear zone at the Grimsel Test Site, Switzerland

Science.gov (United States)

Blechschmidt, I.; Martin, A. J.

2012-12-01

The Grimsel Test Site (www.grimsel.com) is an international underground research laboratory excavated at a depth of 450m below the surface in the crystalline Aare Massif of southern Switzerland in 1984. It is operated and owned by the National Cooperative for the Disposal of Radioactive Waste of Switzerland (NAGRA) which is the organization responsible for managing and researching the geological disposal of all types of radioactive wastes originating in Switzerland. One experiment, the Colloid Formation and Migration test (CFM*), is an ongoing in-situ migration test started in 2004 to study colloid facilitated transport behavior of radionuclides through a shear zone. The importance of colloid transport in the context of a radioactive waste repository is that it provides a mechanism for potentially enhancing the advective transport of radionuclides. The montmorillonite clays that are planned to be used as an engineered barrier around the radioactive waste in many repository concepts may be a source of such colloids under specific hydraulic and/or chemical boundary conditions. The CFM project includes an integrated programme of field testing, laboratory studies and modelling/interpretation. The field tests are performed in a shear zone where the natural outflow has been controlled by a tunnel packer system and flow is monitored with an array of boreholes drilled for CFM and previous experiments at the site. The flow field is controlled by a low-rate extraction from a surface packer. The controlled low-rate extraction creates a region of low hydraulic gradients and fluid velocity within the shear zone, suitable for study under repository-relevant or other geo-resource relevant conditions. Here we present a summary of the migration tracer tests carried out so far to understand the hydraulic properties and transport characteristics of the shear zone using both stable and radioactive (Na-22, Cs-137, Ba-133, Th-232, Np-237, Am-243, Pu-242) tracers as well as colloids, and

Validation study of safety assessment model for radioactive waste disposal

Energy Technology Data Exchange (ETDEWEB)

Munakata, Masahiro; Takeda, Seiji; Kimura, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-12-01

The JAERI-AECL collaboration research program has been conducted to validate a groundwater flow and radionuclide transport models for safety assessment. JAERI have developed a geostatistical model for radionuclide transport through a heterogeneous geological media and verify using experimental results of field tracer tests. The simulated tracer plumes explain favorably the experimental tracer plumes. A regional groundwater flow and transport model using site-scale parameter obtained from tracer tests have been verified by comparing simulation results with observation ones of natural environmental tracer. (author)

Soil homogeneity evaluation by radionuclide tracer breakthrough curve interpretation

International Nuclear Information System (INIS)

Brenizer, J.S. Jr.; Jarrett, A.R.; Jester, W.A.

1980-01-01

Increasing concern about the environmental impact of hazardous waste disposal has made site evaluation and site selection difficult and expensive. Pollutants, assumed to be absorbed by the soil immediately surrounding the burial trench, have been detected far from sites. Discrepancies between predicted migration distances based on indirect methods such as laboratory and computer modeling and those observed at the field site are often significant. The homogeneity of subsurface media, often assumed in laboratory and modeling studies, is seldom found in the field. The use of tracers to determine the flow characteristics of a potential disposal site involves time and expense, but offers a direct evaluation of solute transport and eliminates the assumptions inherent in indirect methods. Current modeling of solute transport in nonhomogeneous porous media is limited by the quantification of input parameters. Several general models can predict solute transport in saturated-unsaturated media from low-level disposal sites if the hydraulic characteristics and chemical reactions expected in each unique water-solute-media system can be defined. The objective of this research was to develop a method of evaluating potential shallow-land burial waste disposal sites by interpreting tracer breakthrough curve structure with respect to the hydrologic properties of the media at the potential disposal site. This methodology will be helpful in evaluating the potential performance of many types of shallow-land waste burial sites such as low-level radioactive waste disposal, surface disposal of flyash, chemical waste disposal, waste sedimentation ponds, and sanitary landfills

Security problems arising from the use of radioactive sources in the study of the wear in refractory linings

International Nuclear Information System (INIS)

Courtois, G.; Hours, R.; Le Clerc, P.; Pons, A.

1960-01-01

The determination of the wear in refractories is a problem to which these are at present only a few solutions, and these limited or delicate to use. That is the reason why the use of radioactive tracers contained in the refractory has met with rapid success. Unfortunately, the development of the method has been retarded by the need to limit severely the amounts of radioelement incorporated and also by the observation that diffusion of the radioactive product occurred in the refractory. As a result, the limiting amount of 1 mc/500 metric tons of cast-iron has been adopted in France, with the proviso that no single source exceeds 3 mc. Further, we have made special sources with a view to avoiding diffusion phenomena. The essential feature of these sources is that they use pyro-ceramic a non porous material having a high melting point and being, very inert chemically. In these sources, the radioelement can either be entirely encased in the pyro-ceramic or be an integral part of its composition. A comparative study of the two types of sources is actually under way. (author) [fr

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.

Radiation exposure as a result of radioactivity in the vicinity of nuclear installations

International Nuclear Information System (INIS)

Van As, Deodandus.

1975-11-01

The nuclear industry in South Africa is expected to expand dramatically and, as a result, the effects of radioactive effluent from these installations on the environment will be of great practical and scientific importance. The long-term effects of low-level radiation cannot be clinically predicted; physical determination and prediction is therefore the accepted measure of radiation exposure. This study includes a survey of all forms of natural and man-made radiation to which the general public is constantly exposed. An intensive study was made of radioactive fallout over South Africa from nuclear bomb tests. From this the general radiation exposure of the South African public could be calculated. It also led to valuable scientific information on mesometeorology and health physics. The latter includes the relationship between air concentration and deposition, the transfer of airborne iodine-131 to milk, and the accumulation of strontium-90 and cesium-137 in human beings as a result of their diets. Thorough environmental studies were conducted at existing nuclear installation sites i.e. Pelinbada which is the site of the National Nuclear Research Centre and Dynefontein which is the proposed site of South Africa's first nuclear power station. These included meso-meteorology, atmospheric dispersion by means of neutron-activable tracers, accumulation factors for important radionuclides in edible marine species by means of stable element tracers, population surveys, background radioactivity surveys etc. From these results critical exposure pathways were established for both sites and the relationship between effluent release and radiation dose to the public was determined. This has lead to the establishment of maximum permissible releases for the operation of the SAFARI-1 research reactor by the Atomic Energy Board and for the specifications of the proposed Koeberg power reactors to be operated by the Electricity Supply Commission at Dynefontein [af

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

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

Search for phosphopeptides in the feces of axenic rats fed radioactive ovine casein

International Nuclear Information System (INIS)

Pelissier, J.P.; Dubos, F.; Daburon, F.

1981-01-01

Radioactive ovine casein was obtained by injecting 100 μCi of 14 C-Ser into the jugular vein of an ewe. The milk collected 17 and 24 h after this injection contained 12% of the radioactivity injected in protein form. The seryl residues were specificially labelled. This casein was used as the only protein source fed to axenic rats; 0.30% of the tracer ingested was found in the feces of those rats. Since phosphoserine represented 25% of the total casein seryl residues, the phosphopeptides may not be selectively unabsorbable [fr

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.

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

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

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

Studies on radioactivity distribution and radioactive mineral identification in uranium ores from Espinharas (PB), Brazil

International Nuclear Information System (INIS)

Oliveira, G.N.M. de.

1979-01-01

Studies about the identification of radioactive minerals in uranium bearing rocks from Espinharas (PB), Brazil are presented. Autoradiography with α-sensitive nuclear emulsions was utilized for determining radioctivity distributions and for localizing radioactive minerals, in combination with microscopy, X-ray diffractometry, PIXE and eletron microprobe analysis for its identification. Mineralized gneisse and feldspatic rock, the two principal samples studied, show distinct differences in radioactive distribution patterns, however the main carriers for U and Th seem to be the same. Microanalysis shows that elements are associated with Si, Ca, Fe and Al an some trace elements like Y, Zr, Ti, etc. U and Th are distributed uniformly in feldspatic rock and inhomogeneously in mineralized gneisse, indicating that the zonary structure of the radioactive cristals, frequently observed in gneisse, could be due to variable U:Th ratios. Chemical analysis, X-ray diffraction datas and microscopic studies indicates that the principal carrier for radioactivity in the rocks of Espinharas is a silicate mineral of U and Th, probably situaded in the series of transition: Coffinite -> uraninite, thorogummite -> thorianite. Some additional experiments about leachability of uranium with diluted sulfuric acid are reported, which confirm the different nature of radioactivity distribution in feldspatic and gneissic rocks. (author) [pt

Underground flux studies in waste basin of CIPC using natural and artificial tracers - v.2

International Nuclear Information System (INIS)

Minardi, P.S.P.

1982-10-01

This report is a complement of the first volume and it has studies with natural tracers to be done on February and March/82, results and conclusions obtained with artificial tracers on March/82, every direction tests and flood course done up to october/82, besides mineralogical and complete qualitative analysis of soil obtained from sounding evidences done in mineral and industrial complex of Pocos de Caldas. (author)

The use of bromine as a tracer for studying infiltrations in mining processes

International Nuclear Information System (INIS)

Diaz, F; Andonie, O; Rojas, X

2003-01-01

The impact of mining activity on underground water is becoming increasingly important because of the scarcity of the resource and due to the different use if there is water under the mining. Once the resource is affected the source of infiltration should be identified in all the processes and systems that are involved in the production system in order to take the appropriate preventive or remedial measures, which should also be the most efficient ones. Tracers play an important role in studying infiltration from mining processes to underground bodies of water. Natural chemical and isotopic tracers can identify the hydrogeological setting and help to establish supported hypotheses about the possible origin of the infiltrations. After the different ideas about the processes or systems that could be infiltrated are presented, the application of additional artificial tracers can resolve any doubts This work presents the use of bromine as a tracer for such studies, because of its specific characteristics as a good tracer in water with low interaction in porous surroundings, generally, and its determination by Neutron Activation Analyzers (NAA) due to its low limits of detection and the technique's precision and accuracy for use at reasonable costs. Given that for this type of study a large number of samples are necessary and that it should be carried out in a time period that does not surpass the duration of the process (a few months), a change had to be made in the methodology usually used for the NAA, which included taking a fraction of significantly less sample while meeting the power requirements for differentiating small changes in concentrations between samples. With this modification a larger number of samples can be irradiated in available positions for these purposes in the RECH-1 and the requirements for the number of samples and response time can be met. After the practical performance of this modification, a comparison between both methodologies was carried

Preliminary evaluation of [1-11C]octanoate as a PET tracer for studying cerebral ischemia. A PET study in rat and canine models of focal cerebral ischemia

International Nuclear Information System (INIS)

Kuge, Yuji; Kawashima, Hidefumi; Hashimoto, Tadatoshi

2000-01-01

Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the tricarboxylic acid (TCA) cycle after β-oxidation. We speculate that [1- 11 C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1- 11 C]octanoate and compared it with cerebral blood flow (CBF) by using rat and canine models of middle cerebral artery (MCA) occlusion and a high resolution PET. In rats brain distribution of [ 15 O]H 2 O measured 1-2 h and 5-6 h after insult was compared with that of [1- 11 C]octanoate measured 3-4 h after insult. Radioactivity ratios of lesioned to normal hemispheres determined with [ 15 O]H 2 O were lower than those determined with [1- 11 C]octanoate. These results were confirmed by a study on a canine model of MCA-occlusion. Twenty-four hours after insult, CBF decreased in the MCA-territory of the occluded hemisphere, whereas normal or higher accumulation of [1- 11 C]octanoate was observed in the ischemic regions. The uptake of [1- 11 C]octanoate-derived radioactivity therefore increased relative to CBF in the ischemic regions, indicating that [1- 11 C]octanoate provides functional information different from CBF. In conclusion, we found that [1- 11 C]octanoate is a potential radiopharmaceutical for studying the pathophysiology of cerebral ischemia. (author)

Radioactive tracers as a tool for the study of in situ meiofaunal-microbial trophic interactions in marine sediments

International Nuclear Information System (INIS)

Carman, K.R.

1989-01-01

Three methods of delivering labeled substrates to natural cores of sediments were compared. Slurried sediments disrupted the sedimentary structure and significantly altered uptake of labeled substrates by copepod species. Thus, disruption of sedimentary structure can significantly alter microbial-meiofaunal interactions and influence the results of grazing studies. The [ 3 H]-thymidine technique for measuring bacterial production was evaluated. The metabolic fate of labeled thymidine in a coastal marine sediment was not consistent with assumptions necessary for measuring bacterial production or its consumption by meiofauna. Microautoradiography was used to demonstrate the sedimentary microalgae and heterotrophic bacteria can be selectively labeled with [ 14 C]bicarbonate and labeled organic substrates, respectively. A study was performed to determine if radioactivity measured in copepods from grazing experiments was the result of ingestion of labeled microorganisms or the result of uptake by non-feeding processes. Uptake of label by copepods from [ 14 C]-bicarbonate was due almost exclusively to grazing on microalgae. Uptake of label by copepods from [ 14 C]-acetate, however, resulted from activity by epicuticular bacteria and was not due to ingestion of labeled bacteria

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

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

Radioactive iodine therapy in cats with hyperthyroidism

International Nuclear Information System (INIS)

Turrel, J.M.; Feldman, E.C.; Hays, M.; Hornof, W.J.

1984-01-01

Eleven cats with hyperthyroidism were treated with radioactive iodine ( 131 I). Previous unsuccessful treatments for hyperthyroidism included hemithyroidectomy (2 cats) and an antithyroid drug (7 cats). Two cats had no prior treatment. Thyroid scans, using technetium 99m, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 5 cats and in both lobes in 6 cats. Serum thyroxine concentrations were high and ranged from 4.7 to 18 micrograms/dl. Radioactive iodine tracer studies were used to determine peak radioactive iodine uptake (RAIU) and effective and biological half-lives. Activity of 131 I administered was calculated from peak RAIU, effective half-life, and estimated thyroid gland weight. Activity of 131 I administered ranged from 1.0 to 5.9 mCi. The treatment goal was to deliver 20,000 rad to hyperactive thyroid tissue. However, retrospective calculations based on peak RAIU and effective half-life obtained during the treatment period showed that radiation doses actually ranged from 7,100 to 64,900 rad. Complete ablation of the hyperfunctioning thyroid tissue and a return to euthyroidism were seen in 7 cats. Partial responses were seen in 2 cats, and 2 cats became hypothyroid. It was concluded that 131 I ablation of thyroid tumors was a reasonable alternative in the treatment of hyperthyroidism in cats. The optimal method of dosimetry remains to be determined

Skeletal scintigraphy and quantitative tracer studies in metabolic bone disease

Science.gov (United States)

Fogelman, Ignac

Bone scan imaging with the current bone seeking radiopharmaceuticals, the technetium-99m labelled diphosphonates, has dramatically improved our ability to evaluate skeletal pathology. In this thesis, chapter 1 presents a review of the history of bone scanning, summarises present concepts as to the mechanism of uptake of bone seeking agents and briefly illustrates the role of bone scanning in clinical practice. In chapter 2 the applications of bone scan imaging and quantitative tracer techniques derived from the bone scan in the detection of metabolic bone disease are discussed. Since skeletal uptake of Tc-99m diphosphonate depends upon skeletal metabolism one might expect that the bone scan would be of considerable value in the assessment of metabolic bone disease. However in these disorders the whole skeleton is often diffusely involved by the metabolic process and simple visual inspection of the scan image may not reveal the uniformly increased uptake of tracer. Certain patterns of bone scan abnormality have, however, been reported in patients with primary hyperparathyroidism and renal osteo-dystrophy; the present studies extend these observations and introduce the concept of "metabolic features" which are often recognisable in conditions with generalised increased bone turnover. As an aid to systematic recognition of these features on a given bone scan image a semi-quantitative scoring system, the metabolic index, was introduced. The metabolic index allowed differentiation between various groups of patients with metabolic disorders and a control population. In addition, in a bone scan study of patients with acromegaly, it was found that the metabolic index correlated well with disease activity as measured by serum growth hormone levels. The metabolic index was, however, found to be a relatively insensitive means of identifying disease in individual patients. Patients with increased bone turnover will have an absolute increase in skeletal uptake of tracer. As a

Tracer Study Lulusan Program Studi Bimbingan dan Konseling Universitas Negeri Gorontalo

Directory of Open Access Journals (Sweden)

Maryam Rahim

2018-01-01

Full Text Available Penelitian ini diharapkan dapat memperbaiki dan meningkatkan kualitas pengelolaan program studi Bimbingan dan Konseling Universitas Negeri Gorontalo berdasarkan informasi yang diperoleh melalui tracer study. Secara khusus, penelitian ini dilakukan untuk memperoleh informasi tentang lulusan, yang meliputi (1 rata-rata masa tunggu lulusan, (2 jenis pekerjaan yang ditekuni, dan (3 tanggapan terhadap pengguna lulusan. Permasalahan penelitian ini adalah: (1 berapa rata-rata masa tunggu lulusan?, (2 jenis pekerjaan apa yang ditekuni lulusan?, dan (3 bagaimana tanggapan pengguna terhadap lulusan?. Anggota populasi dalam penelitian ini berjumlah 408 orang, dari jumlah tersebut 58% (238 orang dijadikan sebagai anggota sampel dengan menggunakan cluster sampling. Indikator penelitian meliputi: (1 rata-rata masa tunggu lulusan, (2 jenis pekerjaan yang ditekuni lulusan, dan (3 tanggapan pengguna terhadap lulusan. Pengumpulan data dilakukan dengan menggunakan instrumen tracer study. Data yang terkumpul dianalisis secara kuantitatif. Hasil penelitian menunjukkan: (1 rata-rata masa tunggu lulusan adalah 3 bulan; (2 jenis pekerjaan yang ditekuni lulusan terdiri dari 13 kategori yakni (a Guru BK (PNS sebanyak 27.31%; (b Guru BK (Non PNS sebanyak 50.00%; (c Guru PAUD sebanyak 0.84%; (d Guru TK sebanyak 5.04%; (e Guru SD sebanyak 4.20%; (f Guru SLB sebanyak 0.42%; (g Pegawai instansi pemerintah sebanyak 2.52%; (h Pegawai perusahaan sebanyak 0.84%; (i Dosen sebanyak 1.26%; (j Dosen luar biasa sebanyak 1.26%; (k Wirausaha sebanyak 3.78%; (l Anggota DPR sebanyak 0.42%; (m dan lain-lain sebanyak 2.10%; dan (3 tanggapan pengguna terhadap lulusan, yang menyangkut: (a  integritas (etika dan moral = 89.60 (sangat baik; (b keahlian berdasarkan bidang ilmu (profesionalisme = 82.92 (baik; (c bahasa Inggris = 67.89 (cukup; (d penggunaan teknologi informasi = 81.71 (baik; (e komunikasi = 84.06 (baik; (f kerjasama tim = 85.04 (sangat baik; dan (g pengembangan diri = 83.83 (baik

Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations; Untersuchungen zur Darstellung traegerarm 73,75Se-markierter Tracer fuer in vivo Untersuchungen

Energy Technology Data Exchange (ETDEWEB)

Helfer, Andreas

2013-04-03

With the growing importance of positron emission tomography (PET) for in vivo imaging in diagnostic medicine there is great interest of developing new labelling methods for the positron emitter selenium-73. As attractive application an examination of a no-carrier-added (n.c.a.) preparation of the analogous tracer Sulindac Selenid and of the selenium containing compound Ebselen was examined with {sup 73,75}Se. First of all a labelling strategy for Sulindac Selenid based on a protected precursor was developed. This precursor should further be transformed into the corresponding standard compound for chomatographic identification of the n.c.a. product. This, however, was not possible. An alternative synthesis method also did not result in a product. Thus, a radioactive labelling in case of Sulindac Selenid was not indicated in spite of a successful synthesis of a precursor. The preparation of Ebselen was performed as earlier described by a sequential one-pot synthesis with a yield of 46 %. An adaption of the reaction parameters to a radiosynthesis with {sup 75}Se failed on the n.c.a. state and also after adding carrier to the reaction mixture. The desired product could, however, be prepared in a copper catalysed one-pot radiosynthesis for the first time under carrier-added conditions. Here, optimized conditions resulted in radiochemical yields of 60 ± 18 %. A no-carrier-added product could finally be achieved using sulphur as nonisotopic carrier in the reaction mixture. After optimisation of reaction parameters n.c.a. [{sup 75}Se]Ebselen could be synthesized with radiochemical yields of 55 ± 7 % within 4 h. Furthermore the desired product could be separated by RHPL-chromatography from its co-produced sulfur-analogue. After transferring the conditions to radiosyntheses with the positron emitter {sup 73}Se, n.c.a. [{sup 73}Se]Ebselen could be achieved with a radiochemical yield of 22 ± 1 % and can now be used as a potential radiotracer in preclinical evaluation

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.

Suitability of 239+240Pu and 137Cs as tracers for soil erosion assessment in mountain grasslands.

Science.gov (United States)

Alewell, Christine; Meusburger, Katrin; Juretzko, Gregor; Mabit, Lionel; Ketterer, Michael E

2014-05-01

Anthropogenic radionuclides have been distributed globally due to nuclear weapons testing, nuclear accidents, nuclear weapons fabrication, and nuclear fuel reprocessing. While the negative consequences of this radioactive contamination are self-evident, the ubiquitous fallout radionuclides (FRNs) distribution form the basis for the use as tracers in ecological studies, namely for soil erosion assessment. Soil erosion is a major threat to mountain ecosystems worldwide. We compare the suitability of the anthropogenic FRNs, 137Cs and 239+240Pu as soil erosion tracers in two alpine valleys of Switzerland (Urseren Valley, Canton Uri, Central Swiss Alps and Val Piora, Ticino, Southern Alps). We sampled reference and potentially erosive sites in transects along both valleys. 137Cs measurements of soil samples were performed with a Li-drifted Germanium detector and 239+240Pu with ICP-MS. Our data indicates a heterogeneous deposition of the 137Cs, since most of the fallout origins from the Chernobyl April/May 1986 accident, when large parts of the European Alps were still snow-covered. In contrast, 239+240Pu fallout originated mainly from 1950s to 1960s atmospheric nuclear weapons tests, resulting in a more homogenous distribution and thus seems to be a more suitable tracer in mountainous grasslands. Soil erosion assessment using 239+240Pu as a tracer pointed to a huge dynamic and high heterogeneity of erosive processes (between sedimentation of 1.9 and 7 t ha(-1) yr(-1) and erosion of 0.2-16.4 t ha(-1) yr(-1) in the Urseren Valley and sedimentation of 0.4-20.3 t ha(-1) yr(-1) and erosion of 0.1-16.4 t ha(-1) yr(-1) at Val Piora). Our study represents a novel and successful application of 239+240Pu as a tracer of soil erosion in a mountain environment. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Joint DOE/NRC field study of tracer migration in the unsaturated zone

International Nuclear Information System (INIS)

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

1986-03-01

The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86

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

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

Soil erosion and suspended sediment transport in an agricultural watershed of Brie. Use of radioactive and magnetic tracers

International Nuclear Information System (INIS)

Sogon, St.

1999-01-01

The degradation of the water quality of rivers by the particulates and the associated pollutants coming from the erosion of agricultural soils is analyzed in the framework of the Piren-Seine program. The area under study is the catchment basin of the Grand Morin river in the Brie plateau (SE of the Paris basin, France). The 137 Cs (T1/2 = 30 years), mainly produced during the atmospheric nuclear tests (1952-1963) is rapidly and strongly fixed to the soil particulates and can be used as a tracer of their migration. These fallout are considered as uniform at the catchment basin scale but those coming from the Tchernobyl accident disturb this labelling. The image obtained from the implementation of the method (reference activity: 3170 Bq/m 2 in January 1, 1996, with 792 Bq/m 2 coming from Tchernobyl) on a 11.2 Ha field (Hardy field, 160 carrots) shows a badly structured 137 Cs redistribution. The mosaic of erosion and accumulation areas shows that the relays represent a major element of the erosion dynamics. No particular element of the landscape can explain the redistribution of the particulates, but the upward part has a more complex functioning with respect to the downward part which has more inclined slopes (>5%). The measurement of the particulates migration on the southern slope (3.5 Ha) of the field allows to calculate a sedimentary status (net erosion ratio: 4 kg/m 2 /year; sedimentary supply ratio: 40%). The study of the suspended matter exported by a buried drainage network (specific of the agriculture of the Brie region) shows strong 137 Cs, 7 Be (T1/2 = 53 days) and 210 Pb (T1/2 = 22 years) activities characteristic of a direct and fast transfer of the thin clay fraction (0.5-0.1 μm) coming from the ploughed layer. In the upstream part of the Vannetin river, the activity of the suspended matter remains identical to the one of the drainage network showing their influence. On the other hand, in the mid-stream part, the sources of suspended matter are

Tracer dispersion in planar multipole flows

International Nuclear Information System (INIS)

Koplik, J.; Redner, S.; Hinch, E.J.

1994-01-01

We study the motion of passive Brownian tracer particles in steady two-dimensional potential flows between sources and sinks. Our primary focus is understanding the long-time properties of the transit time probability distribution for the tracer to reach the sink p(t) and the influence of the flow geometry on this probability. A variety of illustrative case studies is considered. For radial potential flow in an annular region, competition between convection and diffusion leads to nonuniversal decay of the transit time probability. Dipolar and higher multipole flows are found to exhibit generic features, such as a power-law decay in p(t) with an exponent determined by the multipole moment, an exponential cutoff related to stagnation points, and a ''shoulder'' in p(t) that is related to reflection from the system boundaries. For spatially extended sinks, it is also shown that the spatial distribution of the collected tracer is independent of the overall magnitude of the flow field and that p(t) decays as a power law with a geometry-dependent exponent. Our results may offer the possibility of using tracer measurements to characterize the flow geometry of porous media

Calcium metabolism in fluorosis and endemic genu valgum using radioactive tracer, whole body counting and radioimmunoassay

International Nuclear Information System (INIS)

Narasinga Rao, B.

1979-11-01

Endemic fluorosis with extensive skeletal changes has been reported from several parts of India. In recent years a new condition, endemic genu valgum, has been recognized in one of these areas. In both conditions osteosclerosis, particularly of the spine, has been observed, but in genu valgum the most distinctive pathology is osteoporosis in bones of the extremities and presumably as a result the ''knock knees'' that give the syndrome its name. In this project certain aspects of calcium metabolism were investigated in endemic fluorosis and genu valgum and in appropriate control subjects. Calcium kinetics were studied by intravenously injecting a tracer dose of 47 Ca and following for 10 days thereafter the concentration of the tracer in serum and excreta, as well as its total retention in the body (the latter measured by whole body counting). In addition calcium balance was measured on some of the subjects while resident in a metabolic ward. Statistical analysis of the results showed in general a higher metabolic activity of calcium in the fluorosis and genu valgum cases than in the controls (specifically, higher ''turnover'' of calcium in the blood pool and an apparently elevated bone mineralization rate). Whole body retention was somewhat greater in the patients than in the controls. Several measurements were also performed relative to blood chemistry, and in particular the serum concentration of 25-OHD 3 (a metabolite of vitamin D) was measured. There was no evidence that vitamin D deficiency played a significant role in the causation of genu valgum

Antiprotonic Radioactive Atom for Nuclear Structure Studies

International Nuclear Information System (INIS)

Wada, M.; Yamazaki, Y.

2005-01-01

A future experiment to synthesize antiprotonic radioactive nuclear ions is proposed for nuclear structure studies. Antiprotonic radioactive nuclear atom can be synthesized in a nested Penning trap where a cloud of antiprotons is prestored and slow radioactive nuclear ions are bunch-injected into the trap. By observing of the ratio of π+ and π- produced in the annihilation process, we can deduce the different abundance of protons and neutrons at the surface of the nuclei. The proposed method would provide a unique probe for investigating the nuclear structure of unstable nuclei

A Comparative Uptake Study of Multiplexed PET Tracers in Mice with Turpentine-Induced Inflammation

Directory of Open Access Journals (Sweden)

Tingting Huang

2012-11-01

Full Text Available The potential value of multiplexed positron emission tomography (PET tracers in mice with turpentine-induced inflammation was evaluated and compared with 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG for glucose metabolism imaging. These PET tracers included [18F]fluoromethylcholine ([18F]FCH for choline metabolism imaging, (S-[11C]methyl-D-cysteine ([11C]DMCYS for amino acid metabolism imaging, [11C]bis(zinc(II-dipicolylamine ([11C]DPA-Zn2+ for apoptosis imaging, 2-(4-N-[11C]-methylaminophenyl-6-hydroxybenzothiazole ([11C]PIB for β amyloid binding imaging, and [18F]fluoride (18F− for bone metabolism imaging. In mice with turpentine-induced inflammation mice, the biodistribution of all the tracers mentioned above at 5, 15, 30, 45, and 60 min postinjection was determined. Also, the time-course curves of the tracer uptake ratios for inflammatory thigh muscle (IM to normal uninflammatory thigh muscle (NM, IM to blood (BL, IM to brain (BR, and IM to liver (LI were acquired, respectively. Moreover, PET imaging with the tracers within 60 min postinjection on a clinical PET/CT scanner was also conducted. [18F]FDG and 18F− showed relatively higher uptake ratios for IM to NM, IM to BL, IM to BR, and IM to LI than [18F]FCH, [11C]DPA-Zn2+, [11C]DMCYS and [11C]PIB, which were highly consistent with the results delineated in PET images. The results demonstrate that 18F− seems to be a potential PET tracer for inflammation imaging. [18F]FCH and [11C]DMCYS, with lower accumulation in inflammatory tissue than [18F]FDG, are not good PET tracers for inflammation imaging. As a promising inflammatory tracer, the chemical structure of [11C]DPA-Zn2+ needs to be further optimized.

Study of the on line radioactive multicharged ion production

International Nuclear Information System (INIS)

Lecesne, N.

1997-01-01

This work is directly related to the SPIRAL project (Systeme de Production d'Ions Radioactifs Acceleres en Ligne) which will start at GANIL at the end of 1998. The aim of the thesis was to study the on line radioactive multicharged ion beam production stages, i.e. the production and diffusion of the radioactive nuclei in a thick target, their possible transfer up to an ECR ion source and their ionisation. Production cross sections of radioactive neutron rich nuclei, formed by fragmentation of a heavy ion beam in a thick target, were measured. An external target-ECR source system, dedicated to the radioactive noble gases production, and two internal target-ECR source systems, dedicated to the radioactive condensable element production, were built and tested on the SIRa tests bench (Separateur d'Ions Radioactifs). Different detection configurations were elaborated in order to identify the radioactive nuclei and estimate their production yields. Finally, a new method for measuring the overall efficiency of the separator was developed and allowed to study the diffusion properties of radioactive noble gases in various targets. (author)

Ventilation conditions and atmospheric characteristics of a laboratory uranium mine. Application to the distribution of radioactive particles in the respiratory tract