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Sample records for fission tracks tims

  1. The fission track method

    International Nuclear Information System (INIS)

    Hansen, K.

    1990-01-01

    During the last decade fission track (FT) analysis has evolved as an important tool in exploration for hydrocarbon resources. Most important is this method's ability to yield information about temperatures at different times (history), and thus relate oil generation and time independently of other maturity parameters. The purpose of this paper is to introduce the basics of the method and give an example from the author's studies. (AB) (14 refs.)

  2. Fission tracks dating for obsidian

    International Nuclear Information System (INIS)

    Picon, C.

    1991-01-01

    Obsidian from South America are dated by fission tracks methods. Samples are irradiated in a nuclear reactor with a flux of 10 15 n/cm 2 . Results, corrected by 'Plateau' methods, are the following: obsidian from Bolivia: 4.14 x 10 6 yr., Ecuador: 8.79 x 10 5 yr., Colombia: 3.52 x 10 6 yr., Peru: 6.55 x 10 6 yr., Chile: 1.13 x 10 6 yr. (MMZ). 5 refs., 3 tabs

  3. Fission tracks diameters in glasses

    International Nuclear Information System (INIS)

    Garzon Ruiperez, L.; Veiguela, J.

    1974-01-01

    Standard glass microscope slides have been irradiated with fission fragments from the uranium. The etching track conditions have been the same for the series, having changed the etching time only for each specimen. For each glass, a minimum of 250 measurements of the tracks diameters have been made, the distributions of which are the bimodal type. Diameters-etching dependence with time is roughly lineal. Energy determinations have been made with the help of the diameters-energy relations. The calculated values agree very well with the know ones. (author) [es

  4. Fission - track age of the Marjalahti Pallasite

    International Nuclear Information System (INIS)

    Bondar, Yu.V.; Perelygin, V.P.

    2006-01-01

    Full text: Investigation of fossil charged-particle tracks in various mineral phases of extraterrestrial samples is a powerful method for research the early stages of the solar system. Over geological time, meteorites crystals have accumulated a record of tracks produced by heavily charged energetic particles from both internal (spontaneous fission of 238U and some other extinct isotopes) and external sources (galactic cosmic rays with Z>20). The fortunate fact that meteorite grains can accumulate latent and very long-lived tracks since soon after the end of nucleosynthesis in the solar nebula enables one to decode their radiation history and to detect any thermal events in the meteorite cosmic history by revealing these tracks through suitable etching procedures. Only a few minerals in meteorites (mainly phosphates) contain small amount of uranium; the fact that 238 U undergoes fission with fission-decay constant λ f ∼ 8.2x10 -17 yr -1 allows one to use this isotope as a chronometer. By measuring the U concentration in the crystals (by reactor irradiation) and the density of the spontaneous-fission tracks it is relatively easy to calculate the 'fission-track age' if 238 U is the main source of fission tracks. However the fission-track dating of extraterrestrial samples compared with the terrestrial ones has some peculiar features due to presence of a number of other potential track sources except the spontaneous fission of 238 U, such as the spontaneous fission of presently extinct 244 Pu, heavy nuclei of cosmic rays and induced fission by cosmic ray primaries. Only tracks from the spontaneous fission of U and Pu are suitable for fission-track dating. The competing effects of these fissioning elements, whose half-lives differ by a factor of ∼50, form a basis for a fission-track chronology for samples older than ∼ 4.0 Gyr. Over small intervals in time (∼ few x10 8 yr ) the track density from spontaneous fission of 238 U is nearly constant. However, the

  5. Fission track geochronology of Eastern Ghats

    Energy Technology Data Exchange (ETDEWEB)

    Virk, H S; Koul, S L; Singh, S [Punjabi Univ., Patiala (India). Dept. of Physics

    1978-12-01

    Fission track geochronology of Eastern Ghats has been established by using fission track technique in dating micaceous and accessory minerals occurring in the region. Annealing studies confirm that radiation damage fossil tracks can be erased in minerals under intense metamorphic episodes thus resetting the geological clock. The fission track ages of the minerals range between 450 +- 5 m.y. to 622 +- 148 m.y. It is concluded that f.t. ages of the minerals date the last metamorphic event of the Eastern Ghats, known as the Indian Ocean Cycle.

  6. Fission track dating of zircon: a multichronometer

    International Nuclear Information System (INIS)

    Carpena, J.

    1992-01-01

    Scattering in Fission Track ages of zircons of a single rock is possible when they present morphological and geochemical variations, if the greatest care is not taken in the choice of the etching conditions and the counting of tracks. The Fission Track study of two heterogeneous populations of zircons from the Mont Blanc granite and from the Gran Paradiso gneisses allows to show that zircon may work as a multichronometer

  7. An improved technique for fission track dating

    International Nuclear Information System (INIS)

    Zhao Yunlong; Wu Zhaohui; Xia Yuliang

    1996-01-01

    The necessity of improving the fission track dating (FTD) technique both at home and abroad is illustrated. The ways of making such improvement are also proposed. It is suggested to calibrate the constant b value of the uranium standard glass by using the method of fission products activity. The 3 kinds of uranium standard glass which have been calibrated are NBS SRM962a, UB 1 and UB 2 . An established new method σ·Φ ρ d /b, to measure neutron fluence, avoids the influence of the varying neutron spectrum on measuring neutron fluence. The improved etching technique for fission tracks in zircon adopted a two-step method which includes the molten alkali system etching using NaOH + KOH and the mixed acid system etching using HNO 3 + HF; this technique results in adequate track etching, increased track clarity and less interference. In this way the intensity of tracks is authentically reflected. Dividing angular zone in accordance with the angular distribution of spontaneous fission track on the crystal surface of minerals to count the tracks and using the improved etching technique to remove the non-uniform angular distribution of spontaneous fission tracks in zircon, ensure the accuracy of tracks count. The improved FTD techniques were used to finish Laboratory Standardized Calibration. The tests using international FTD age standards samples have proved that above mentioned techniques are reliable and practical in obtaining the accurate FTD data. (8 tabs.; 3 figs.)

  8. Fission track method for uranium ore exploration

    International Nuclear Information System (INIS)

    Guo Shilun; Deng Xinlu; Sun Shengfen; Meng Wu; Zhang Pengfa; Hao Xiuhong

    1986-01-01

    The uranium concentrations in natural water collected in the fields of uranium ore exploration with fission track method have been determined. It shows that the results of fission track method are consistent with that of fluoro-colorimetry and laser fluorometry for the same samples of water with uranium concentration in the region of 10 -4 to 10 -8 g/l. For water samples with lower uranium concentration (≤10 -8 g/l), the fission track method can still give accurate or referential results, but the other two methods failed. The reproducibility of fission track method was checked and discussed by using samples collected in the same fields of uranium ore exploration. The effects of the concentration of the impurities in natural water on determination of uranium concentration were analysed and discussed as well

  9. Muon induced fission and fission track dating of minerals

    International Nuclear Information System (INIS)

    Marques, A.

    1988-01-01

    The effects of muon induced fission on geological dating of samples by the fission track method are evaluated for the case of muscovite minerals. It is found a small but significant effect, greater for the longer ages. Since calculations are developped under the hypothesis of constant atmosphere and primary cosmic ray flux it is suggested that any discrepancy found in ages of very old material that cannot be accounted for by well known environmental influences, be taken as an indication of variation on either the atmospheric stopping power or the intensity of cosmic radiation along the ages. (author) [pt

  10. Fission track dating of kimberlitic zircons

    International Nuclear Information System (INIS)

    Haggerty, S.E.

    1983-01-01

    The only reliable method for dating kimberlites at present is the lengthy and specialized hydrothermal procedure that extracts 206 Pb and 238 U from low-uranium zircons. This paper describes a second successful method by fission track dating of large single-crystal zircons, 1.0-1.5 cm in dimension. The use of large crystals overcomes the limitations imposed in conventional fission track analysis which utilizes crushed fragments. Low track densities, optical track dispersion, and the random orientation of polished surfaces in the etch and irradiation cycle are effectively overcome. Fission track ages of zircons from five African kimberlites are reported, from the Kimberley Pool (90.0 +- 6.5 m.y.), Orapa (87.4 +- 5.7 and 92.4 +- 6.1 m.y.), Nzega (51.1 +- 3.8 m.y.), Koffiefontein (90.9 +- 8.2 m.y.), and Val do Queve (133.4 +- 11.5 m.y.). In addition we report the first radiometric ages (707.9 +- 59.6 and 705.5 +- 61.0 m.y.) of crustal zircons from kimberlites in northwest Liberia. The fission track ages agree well with earlier age estimates. Most of the zircons examined in this study are zoned with respect to uranium but linear correlations are established (by regression analysis) between zones of variable uranium content, and within zones of constant uranium content (by analysis of variance). Concordance between the fission track method and the U/Pb technique is established and we concluded that track fading from thermal annealing has not taken place. Kimberlitic zircons dated in this study, therefore, record the time of eruption. (orig.)

  11. Obsidian dating by fission track method

    International Nuclear Information System (INIS)

    Araya, A.M.O.

    1990-12-01

    The fission track method was employed to obtain the age of twelve obsidian sample from Ecuador. By using the plateau-age correction method, we obtained the true age of each sample and were able to identify four groups of ages in the studied area. Thereafter we studied the fading of fission tracks in two obsidian samples with different origins: Yanaurcu, Ecuador and Monte Arci, Italy. We constructed Arrhenius plots and calculated activation energies for both samples. The results from thermal annealing experiments were compared with theoretical curves obtained by integrating an equation proposed by Shukolyukov et al (1965). (author). 43 refs, 20 figs, 10 tabs

  12. Fission track imaging of the Australian continent

    International Nuclear Information System (INIS)

    Gleadow, A.; Kohn, B.; O'Sullivan, P.; Brown, R.; Gallagher, K.

    1999-01-01

    Full text: Techniques to reconstruct the thermal histories of rocks in the low-temperature environment of the upper crust have previously found important applications in such areas as sedimentary basin analysis, the evolution of convergent orogenic belts and studies of extensional tectonic environments. Increasingly large sets of thermochronology data are now becoming available on an even larger scale from the apatite fission-track system (for temperatures <∼110 deg C). Additional information is also now starting to emerge at even lower temperatures (<∼75 deg C) from the apatite (U-Th)/He system. The results from such systems can be used in novel ways to examine and visualise the evolution of the upper part of the continental crust. Quantitative modelling has brought a new dimension to this work and forward-modelling procedures are now well established which give 'best fit' thermal histories for temperatures less than about 110 deg C. In many cases the modelled thermal histories provide a proxy for rock transport towards the surface as overlying material is removed by denudation. Such information allows a reconstruction of the denudation history of the land surface. Applying these modelling procedures to large regional arrays of fission-track data means that the thermal history information can now be integrated with other regional data sets to provide an important new perspective on crustal and surface evolution. Apatite fission track analysis has now been completed on nearly 3000 surface outcrop samples across Australia under an AGCRC project to image the thermotectonic evolution of the exposed basement rocks of the continent. The samples analysed are mostly from rocks of broadly granitic composition and the apatites separated from these are overwhelmingly fluorapatites, which are consistent in their fission-track annealing properties with those on which the numerical annealing models are based. By interpolating the calculated thermal histories a series of

  13. Application of fission track analysis to hydrocarbon exploration

    International Nuclear Information System (INIS)

    Duddy, I.R.; Green, P.F.; Gleadow, A.J.W.; Marshallsea, S.; Tingate, P.; Laslett, G.M.; Hegarty, K.A.; Lovering, J.F.

    1985-01-01

    The temperature range over which fission tracks in apatite show observable annealing effects coincides with that responsible for the maximum generation of liquid hydrocarbons. Work is currently in progress in a number of Australian and overseas sedimentary basins, applying Apatite Fission Track Analysis (AFTA) to investigate the thermal evolution of these hydrocarbon prospective regions

  14. Uranium content of petroleum by fission track technique

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Mafra, O.Y.; Oliveira, C.A.N. de; Pinto, L.R.

    1981-03-01

    The feasibility of the fission track registration technique to investigate the natural uranium concentration in petroleum is examined. The application of this technique to petroleum is briefly described and discussed critically. The results obtained so far indicate uranium concentrations in samples of Brazilian petroleum which are over the detect ion limit of fission track technique. (Author) [pt

  15. Uranium content of petroleum by Fission track technique

    International Nuclear Information System (INIS)

    Paschaa, A.S.; Mafra, O.Y.; Oliveira, C.A.N.; Pinto, L.R.

    1982-01-01

    This paper examines the feasibility of the fission track registration technique to investigate the natural uranium concentration in petroleum. The application is briefly described and the results obtained indicate the presence of uranium concentrations in samples of Brazilian petroleum which are over the detection limit of the fission track technique. The irradiations were performed by using fluxes with predominance of thermal neutrons, which have a fission cross-section for U 235 equal to 579 barns. Since the neutron fluxes were not comp sed exclusively of thermal neutrons, fissions from fast neutrons would also be taken into account for U 238 and Th 232

  16. Measurement of fission track of uranium particle by solid state nuclear track detector

    International Nuclear Information System (INIS)

    Son, S. C.; Pyo, H. W.; Ji, K. Y.; Kim, W. H.

    2002-01-01

    In this study, we discussed results of the measurement of fission tracks for the uranium containing particles by solid state nuclear track detector. Uranium containing silica and uranium oxide particles were prepared by uranium sorption onto silica powder in weak acidic medium and laser ablation on uranium pellet, respectively. Fission tracks for the uranium containing silica and uranium oxide particles were detected on Lexan plastic detector. It was found that the fission track size and shapes depend on the particle size uranium content in particles. Correlation of uranium particle diameter with fission track radius was also discussed

  17. Fission-track ages and their geological interpretation

    International Nuclear Information System (INIS)

    Wagner, G.A.

    1981-01-01

    In fission-track dating, experimental procedures such as etching and thermal pre-treatment may strongly affect the age values determined and their geological interpretation. This peculiarity is due to the common phenomenon of partial fading of fossil (spontaneous-) fission tracks during a sample's geological history. The proper geological interpretation of the age data must take into account the specific experimental conditions, the stability characteristics and size distribution of fission tracks in the sample, the ages of co-existing minerals, and the independent information about the thermal history of the geological region. (author)

  18. Fission-track studies of uranium distribution in geological samples

    International Nuclear Information System (INIS)

    Brynard, H.J.

    1983-01-01

    The standard method of studying uranium distribution in geological material by registration of fission tracks from the thermal neutron-induced fission of 235 U has been adapted for utilisation in the SAFARI-1 reactor at Pelindaba. The theory of fission-track registration as well as practical problems are discussed. The method has been applied to study uranium distribution in a variety of rock types and the results are discussed in this paper. The method is very sensitive and uranium present in quantities far below the detection limit of the microprobe have been detected

  19. The relationship between fission track length and track density in apatite

    International Nuclear Information System (INIS)

    Laslett, G.M.; Gleadow, A.J.W.; Duddy, I.R.

    1984-01-01

    Fission track dating is based upon an age equation derived from a random line segment model for fission tracks. This equation contains the implicit assumption of a proportional relationship between the true mean length of fission tracks and their track density in an isotropic medium. Previous experimental investigation of this relationship for both spontaneous and induced tracks in apatite during progressive annealment model in an obvious fashion. Corrected equations relating track length and density for apatite, an anisotropic mineral, show that the proportionality in this case is between track density and a length factor which is a generalization of the mean track length combining the actual length and crystallographic orientation of the track. This relationship has been experimentally confirmed for induced tracks in Durango apatite, taking into account bias in sampling of the track lengths, and the effect of the bulk etching velocity. (author)

  20. Characteristics of diallyl phthalate resin as a fission track detector

    CERN Document Server

    Tsuruta, T

    1999-01-01

    Diallyl phthalate (DAP) resin plates were irradiated with fission fragments, and then etched in aqueous solution of KOH. Etched tracks were observed and counted by using an optical microscope. The detection efficiency of fission fragments was about 100% for both perpendicular and random incidence. DAP plates were insensitive to alpha particles and fast neutrons. These characteristics are suitable for detecting selected fission fragments, which coexist with alpha particles or fast neutrons. DAP plates are valuable for quantitative analysis of fissionable materials and neutron dosimetry. DAP and allyl diglycol carbonate (CR-39) were formed into copolymers in various ratios. The copolymers showed intermediate characteristics between DAP and CR-39. The fabrication of the copolymers made it possible to control the discrimination level for detection of heavy charged particles.

  1. The changing face of fission track dating: recent advances

    International Nuclear Information System (INIS)

    Green, P.F.; Duddy, I.R.; Gleadow, A.J.W.; Laslett, G.M.; Hegarty, K.A.; Lovering, J.F.

    1985-01-01

    Fission Track Dating has undergone something of a renaissance in recent years. What began as a rather unreliable method of geochronology has now become a rigorous and dependable means of measuring not only geological time but also paleotemperatures. Developments such as the zeta calibration technique, rigorous satistical data analysis, investigation of confined track lengths and detailed studies of annealing behaviour have all contributed to advances in the technique

  2. The analysis of projected fission track lengths

    International Nuclear Information System (INIS)

    Laslett, G.M.; Galbraith, R.F.; Green, P.F.

    1994-01-01

    This article deals with the question of how features of the thermal history can be estimated from projected track length measurements, i.e. lengths of the remaining parts of tracks that have intersected a surface, projected onto that surface. The appropriate mathematical theory is described and used to provide a sound basis both for understanding the nature of projected length measurements and for analysing observed data. The estimation of thermal history parameters corresponding to the current temperature, the maximum palaeotemperature and the time since cooling, is studied using laboratory data and simulations. In general the information contained in projected track lengths and angles is fairly limited, compared, for example, with that from a much smaller number of confined tracks, though we identify some circumstances when such measurements may be useful. Also it is not straightforward to extract the information and simple ad hoc estimation methods are generally inadequate. (author)

  3. Fission-track evidence of tectonic evolution in the northwestern ...

    Indian Academy of Sciences (India)

    Guo-Qiang Sun

    2018-02-14

    Feb 14, 2018 ... from further collision of the Indian and Eurasian plates along the Yarlung Tsangpo suture zone. Strata ... Kunlun orogenic belt system using fission-track analysis of ... which had a decisive role in the development and ... boundary of the basin (Yue et al. ... Tagh fault commenced strike-slip movement (Yue.

  4. Influence of the cosmic-ray induced fission tracks on the fission track of extraterrestric minerals via the 238U spontaneous fission

    International Nuclear Information System (INIS)

    Damm, G.; Thiel, K.

    1977-01-01

    The age determined by counting fission tracks of lunar and meteorite materials is obviously falsified by additional fission track parts not to be accounted for by the spontaneous fission of uranium 238. For this p and n induced fissions of U, Th and other hreavy elements through the cosmic radiation come into consideration. In order to determine the possible part of such interference factors, a simulation experiment at the proton synchrocycloton (CERN, Geneva) has been carried out and independently of this, the production rates for the p and n induced U, Th, Bi, Pb and Au in the surface-near regolith layers of the moon were calculated. It could be seen that the irradiation age as well as the spacial distribution of the heavy metals in the samples to be dated must be considered. (RB) [de

  5. Chemical etching of fission tracks in ethylene-tetrafluoroethylene copolymer

    International Nuclear Information System (INIS)

    Komaki, Y.; Tsujimura, S.; Seguchi, T.

    1979-01-01

    The chemical etching of fission tracks in ethylene-tetrafluoroethylene copolymer was studied. Etched holes 3000 to 4000 A in diameter were recognized by electron microscopy for a film bombarded by fission fragments in oxygen and etched in a 12N sodium hydroxide solution at 125 0 C. The radial etching rate at 125 0 C was 6 to 8 A/hr, which is less than 17 A/hr for polyvinylidene fluoride in the same sodium hydroxide concentration at 85 0 C. The smaller rate is a reflection of the larger chemical resistivity of ethylene-tetrafluoroethylene copolymer than polyvinylidene fluoride. (author)

  6. p- and n-induced U-fission tracks as possible error sources in the fission track dating of extraterrestric samples

    International Nuclear Information System (INIS)

    Thiel, K.

    1975-01-01

    Using the fission track dating method by means of uranium fission tracks in meteorites and moon samples (according to the successful Apollo and Luna missions), special problems arise, as the samples frequently have a very great age and were subjected to the inmediate effect of primary cosmic radiation. To determine the share of induced fission tracks, an extended 'cosmic ray' simulation experiment was carried out on the p-synchrocyclotron in CERN, Geneva; the performance and results of the test with the proton flux and U fission track measurements are dealt with in detail. (HK/LH) [de

  7. A new look at statistics in fission-track dating

    International Nuclear Information System (INIS)

    Green, P.F.

    1981-01-01

    Poissonian errors, as routinely applied in fission-track dating, represent a limiting case, which may not always be attainable in practice. Other experimental factors may introduce additional non-Poissonian errors, which must be taken into account. In the population method, sampling of non-homogeneous uranium distributions introduces experimental error. In the external detector method (EDM), many factors exist to introduce such error. Simply quoting total numbers of spontaneous and induced fission tracks obtained by the EDM may disguise the possible influence of experimental variation. The present work concentrates on the EDM, and describes a test which has recently been proposed to detect the presence of experimental error in EDM analyses. The question of an alternative analysis for cases where such error is present is also considered. A method of presenting EDM data is suggested, which allows assessment of the importance of experimental errors. (author)

  8. Inverse modelling of thermal histories with apatite fission tracks

    International Nuclear Information System (INIS)

    El Lmrani, A.; Zine El Abidine, H.; Limouri, M.; Essaid, A.; POupeau, G.

    1998-01-01

    The problem of modelling thermal histories lies in the exploration of a time-temperature space, usually so broad, in order to identify the optimal paths. For overcoming this difficulty, many approaches were proposed, using linear and non-linear optimisation algorithms. Generally, these approaches do not take into account the experimental data (fission track age [FTA] and fission track length distribution [FTLD]) to better aim the search strategy. The present work shows that experimental data hold some precious information, for which it should be known how to extract it. In fact, it allows us to tighten the time-temperature space of search, supposed to contain the optimal solutions. A genetic algorithm is also used in this work to perform the search for these optimal solutions. (authors)

  9. Obsidian ages from Ecuador by the fission track dating

    International Nuclear Information System (INIS)

    Osorio, A.M.; Hadler, J.C.; Bigazzi, G.; Norelli, P.; Coltelli, M.; Salazar, E.

    1991-01-01

    Fission track dating was applied in order to study obsidian samples originated from Mullumica and Callejones flows, Oyacachi, Ecuador. Preliminary data show that the ratio between the mean diameter os spontaneous and induced tracks is about 0.9, an indication that the analysed samples were submitted to small fading during their geological histories. Ages were obtained around 0.2 x 10 6 a, in agreement with Miller and Wagners's results. Ages ranging from 0.17 x 10 6 a up to 0.23 x 10 6 a were obtained correcting the apparent ages by means of the plateau method. (author)

  10. Liquid nitrogen enhancement of partially annealed fission tracks in glass

    International Nuclear Information System (INIS)

    Pilione, L.J.; Gold, D.P.

    1976-01-01

    It is known that the number density of fission tracks in solids is reduced if the sample is heated before chemical etching, and the effect of annealing must be allowed for before an age can be assigned to the sample. The extent of annealing can be determined by measuring the reduction of track parameters (diameter and/or length) and comparison with unannealed tracks. Correct ages can be obtained by careful calibration studies of track density reduction against track diameter or length reduction at different annealing temperatures and times. For crystallised minerals, however, the resulting correction techniques are not generally valid. In the experimental work described glass samples were partially annealed and then immersed in liquid N 2 for various periods, and it was shown that the properties of the glass and the track parameters could be altered so as to observe tracks that would normally be erased by annealing. The results of track density measurements against liquid N 2 immersion times are shown graphically. A gain of about 40% was achieved after 760 hours immersion time. The size of the tracks was not noticeably affected by the immersion. It was thought that thermal shock might be the cause of the track enhancement, but it was found that repeated immersion for about 2 hours did not lead to an increase in track density. Other studies suggest that the mechanism that erases the tracks through annealing may be partially reversed when the temperature of the sample is significantly lowered for a sufficient length of time. Further work is under way to find whether or not the process of enhancement is a reversal of the annealing process. Similar enhancement effects using liquid N 2 have been observed for d-particle tracks in polycarbonate detectors. (U.K.)

  11. Thermal significance of fission-track length distributions

    International Nuclear Information System (INIS)

    Crowley, K.D.

    1985-01-01

    The semi-analytical solution of an equation describing the production and shortening of fission tracks in apatite suggests that certain thermal histories have unique length-distribution 'signatures'. Isothermal-heating histories should be characterized by flattened, length-shortened distributions; step-heating histories should be characterized by bimodal track length distributions; and linear-cooling histories should be characterized by negatively skewed, length-shortened distributions. The model formulated here to investigate track length distributions can be used to constrain the thermal histories of natural samples for which unbiased track length data are available - provided that the geologic history of the system of interest can be used to partially constrain one of the unknowns in the model equations, time or temperature. (author)

  12. Optical efficiency for fission fragment track counting in Muscovite solid state track recorders

    International Nuclear Information System (INIS)

    Roberts, J.H.; Ruddy, F.H.; Gold, R.

    1984-01-01

    In order to determine absolute fission rates from thin actinide deposits placed in direct contact with Muscovite Solid State Track Recorders, it is necessary to know the efficiency with which fission fragment tracks are recorded. In this paper, a redetermination of the 'optical efficiency', i.e. the fraction of fission events recorded and observed in the Muscovite is reported. The value obtained from a well-calibrated thin deposit of 252 Cf and Muscovite etched about 90 min. in 49% HF at room temperature, is 0.9875 +- 0.0085. Manual counting was used. Preliminary results from a deposit of 242 Pu are also reported, along with preliminary comparisons of track counting with an automated system. Reasons for the discrepancy of the optical efficiency reported here with an earlier measurement are also reported. (author)

  13. Optical efficiency for fission-fragment track counting in Muscovite Solid-State Track Recorders

    International Nuclear Information System (INIS)

    Roberts, J.H.; Ruddy, F.H.; Gold, R.

    1983-07-01

    In order to determine absolute fission rates from thin actinide deposits placed in direct contact with Muscovite Solid-State Track Recorders, it is necessary to know the efficiency with which fission-fragment tracks are recorded. In this paper, a redetermination of the optical efficiency, i.e., the fraction of fission events recorded and observed in the Muscovite, is reported. The value obtained from a well-calibrated thin deposit of 252 Cf and Muscovite etched about 90 min. in 49% HF at room temperature, is 0.9875 +- 0.0085. Manual counting was used. Preliminary results from a deposit of 242 Pu are also reported, along with preliminary comparisons of track counting with an automated system. Reasons for the discrepancy of the optical efficiency reported here with an earlier measurement are also reported. 5 references, 1 figure, 3 tables

  14. The fission-track analysis: An alternative technique for provenance studies of prehistoric obsidian artefacts

    CERN Document Server

    Bellot-Gurlet, L; Dorighel, O; Oddone, M; Poupeau, G; Yegingil, Z

    1999-01-01

    Comparison of fission-track parameters - age and track densities - is an alternative tool for correlating obsidian artefacts with their potential natural sources. This method was applied by different fission-track groups in various regions and results were compared with those obtained using the more popular provenance identification techniques based on chemical composition studies. Hundreds of analyses prove that fission-track dating is a complementary technique which turns out to be very useful, specially when the chemical composition does not fully discriminate different sources. Archaeologically significant results were obtained applying the fission-track analysis in various regions of earth.

  15. The fission-track analysis: An alternative technique for provenance studies of prehistoric obsidian artefacts

    International Nuclear Information System (INIS)

    Bellot-Gurlet, L.; Bigazzi, G.; Dorighel, O.; Oddone, M.; Poupeau, G.; Yegingil, Z.

    1999-01-01

    Comparison of fission-track parameters - age and track densities - is an alternative tool for correlating obsidian artefacts with their potential natural sources. This method was applied by different fission-track groups in various regions and results were compared with those obtained using the more popular provenance identification techniques based on chemical composition studies. Hundreds of analyses prove that fission-track dating is a complementary technique which turns out to be very useful, specially when the chemical composition does not fully discriminate different sources. Archaeologically significant results were obtained applying the fission-track analysis in various regions of earth

  16. Development of nuclear microfilters using the fission tracks registration technique

    International Nuclear Information System (INIS)

    Yamasaki, I.M.; Geraldo, L.P.

    1990-10-01

    Nuclear microfilters with mean pores diameter in the range from 1.9 to 10.6 μm have been produced using the fission tracks registration technique in Makrofol KG (8 μm thickness). Fluctuations around 11% and 10% were obtained respectively for the pores size and pores uniformity in the analysis of a typical sample of microfilter. The essential features of the microfilters were similar to those ones, commercially known as Nuclepore and thus they may be routinely employed in the several applications areas of the Industry and Biology. (author)

  17. Thorium determination in water and biological materials by fission track

    International Nuclear Information System (INIS)

    Melo Ferreira, A.C. de.

    1989-01-01

    As a segment of a research programme on the study of bioaccumulation of radionuclides, in animals and vegetables from Morro do Ferro, Pocos de Caldas, MG, a fission track method for the determination of low levels of thorium in environmental samples was developed as an alternative for alpha spectroscopy. The study was carried out in early alpha spectroscopy samples, containing high levels of 228 Th activity, which makes difficult the 232 Th determination. A dry way method for thorium evaluation was developed. Pieces of membrane filters, containing La F 3 (Th), coupled to Makrofol detectors, were irradiated in the core of a research reactor, IEA-R1 (IPEN). (author)

  18. Fission track dating and estimation of uranium in some garnets of Rajasthan (India)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S; Virk, H S [Punjabi Univ., Patiala (India). Dept. of Physics

    1978-09-01

    The experimental procedure, involving the preparation, etching, thermal neutron irradiation and scanning of the garnet samples, is described. The calculated fission track ages and uranium concentration are tabulated.

  19. Dating method by fission tracks: some Brazilian examples

    International Nuclear Information System (INIS)

    Fonseca, Ariadne do Carmo

    1996-01-01

    The Fission Track method (TF) complements the dating of a interval of tectonic events occurred in low temperatures not detected by another radiometric methods. In the South part of Craton of Sao Francisco the dating of apatites of archaean rocks produced ages TF between 900 and 500 Ma, reflecting the progressive acting of the Brazilian margin mobile belts in the archaean craton areas. Apatite of some igneous and metamorphic rocks of the Braziliana age, in the Faixa Ribeira segment, between the Rio de Janeiro and Salvador cities, produced TF ages between 140 and 80 Ma. The basaltic and alkaline volcanism related to the Atlantic Ocean opening dated from this interval. The TF dating in apatites of the continental margin rocks allowed to date the event. In the Cabo Frio region (Southeastern part of Rio de Janeiro State), titanite and apatite of the Transamazonic orthognaisses produced TF dates between 190 and 80 to 40 Ma. The age around 190 Ma date previously the rift formation precursor of the South Atlantic Ocean opening, while the ages between 80 and 40 Ma were related to the alkaline rocks intrusion. The examples mentioned demonstrate the event diversity which may be dated by the Fission Tracks method, mainly in the craton area and margin belts study

  20. On methodical problems in estimating geological temperature and time from measurements of fission tracks in apatite

    International Nuclear Information System (INIS)

    Jonckheere, R.

    2003-01-01

    The results of apatite fission-track modelling are only as accurate as the method, and depend on the assumption that the processes involved in the annealing of fossil tracks over geological times are the same as those responsible for the annealing of induced fission tracks in laboratory experiments. This has hitherto been assumed rather than demonstrated. The present critical discussion identifies a number of methodical problems from an examination of the available data on age standards, borehole samples and samples studied in the framework of geological investigations. These problems are related to low- ( 60 deg. C) annealing on a geological timescale and to the procedures used for calculating temperature-time paths from the fission-track data. It is concluded that it is not established that the relationship between track length and track density and the appearance of unetchable gaps, observed in laboratory annealing experiments on induced tracks, can be extrapolated to the annealing of fossil tracks on a geological timescale. This in turn casts doubt on the central principle of equivalent time. That such uncertainties still exist is in no small part due to an insufficient understanding of the formation, structure and properties of fission tracks at the atomic scale and to a lack of attention to the details of track revelation. The methodical implications of discrepancies between fission track results and the independent geological evidence are rarely considered. This presents a strong case for the re-involvement of track physicists in fundamental fission track research

  1. Determination of palaeotemperatures of apatite with the fission-track method

    International Nuclear Information System (INIS)

    Bertagnolli, E.; Maerk, E.; Bertel, E.; Pahl, M.; Maerk, T.D.

    1981-01-01

    As a consequence of thermal fading of fission tracks in minerals, the fission-track dating method can be used to obtain a sensitive geothermometer for unfolding thermal events in the history of rocks, especially if it is possible to determine the temperature associated with a measured fission-track age, i.e., yielding a temperature age. Based on the concept of a minimum fission-track length the differential annealing equation has been solved for apatite, taking into account the fact that the annealing coefficient depends also on the degree of fission-track reduction. This allows us to calculate an improved age-temperature relationship for apatite, which gives for a measured corrected fission-track age the corresponding temperature, assuming either linear or exponential time-dependence of the temperature. The present results for apatite are compared with previous calculations in apatite and sphene. As expected, a fission-track age of apatite dates a younger (lower temperature) point in the thermal-cooling history than a fission-track age of sphene. (author)

  2. Dating by fission tracks in archaeology. 1. Principles and experimental methods

    International Nuclear Information System (INIS)

    Poupeau, G.; Zuleta, E.

    1984-01-01

    The principles of dating method by uranium fission tracks are shortly exposed. The conditions of application to the archaeology are discussed, in particular for the volcanic glasses, where the fossil fission tracks are often affected of a beginning of effacement. (L.C.) [pt

  3. Dating by fission track method: study of neutron dosimetry with natural uranium thin films

    International Nuclear Information System (INIS)

    Iunes, P.J.

    1990-06-01

    Fission track dating is described, focalizing the problem of the decay constant for spontaneous fission of 238 U and the use of neutron dosimetry in fission track analysis. Experimental procedures using thin films of natural uranium as neutron dosimeters and its results are presented. The author shows a intercomparison between different thin films and between the dosimetry with thin film and other dosimetries. (M.V.M.). 52 refs, 12 figs, 9 tabs

  4. Automatic counting of fission fragments tracks using the gas permeation technique

    CERN Document Server

    Yamazaki, I M

    1999-01-01

    An automatic counting system for fission tracks induced in a polycarbonate plastic Makrofol KG (10 mu m thickness) is described. The method is based on the gas transport mechanism proposed by Knudsen, where the gas permeability for a porous membrane is expected to be directly related to its track density. In this work, nitrogen permeabilities for several Makrofol films, with different fission track densities, have been measured using an adequate gas permeation system. The fission tracks were produced by irradiating Makrofol foils with a 252Cf calibrated source in a 2 pi geometry. A calibration curve fission track number versus nitrogen permeability has been obtained, for track densities higher than 1000/cm sup 2 , where the spark gap technique and the visual methods employing a microscope, are not appropriate for track counting.

  5. Dating of zircons by the fission track method

    International Nuclear Information System (INIS)

    Tenorio Hernandez, L.M.

    1992-01-01

    This work describes the methodology to date zircons by the Fission Track Method. A brief discussion is made of the physical principles of the method, physical properties of zircons and the geochemical properties of uranium. When starting with a hand sample, a mineral separation is required; to do this the following steps are needed: crushing and sieving of the sample, washing and drying, magnetic separation, heavy liquid separation (Bromoform 2.89 g/cm 3 , Diyodomethane = 3.31 g/cm 3 ), and manual separation on a stereoscopic microscope. Once the zircon concentrate is obtained, these are mounted on a FEP teflon mount, then polished and etched on an eutectic mix of 10 g. of KOH + 7.2 g. of NaOH, heated to 210 Centigrade degrees. Afterwards the mounts are prepared for irradiation, sterilizing and putting on top of them an external detector (a thin sheet of muscovite poor in uranium content). The package is then wrapped in plastic and sent to the reactor together with standard zircons of known age (Fish Canyon Tuff: Naeser et.al., 1981), mounted in the same way, plus standard glasses of known uranium content. The package was irradiated in a site known as SIRCA (Rotatory Capsules Irradiation System). Then the package is left to decay for several days, and then the external detectors are etched in a 48% concentrated hydrofluoric acid for 5 minutes. Once the samples are processed through the mentioned steps, spontaneous tracks appear in the zircons and induced tracks appear in the external detectors. On counting the tracks one obtains ρ s (spontaneous track density) and ρ 1 (induced track density). These two parameters together with another one called '#zeta #' (obtained from the standard zircons and glasses), are used to obtain the age of the sample. Zircons from Cerro de Mercado, Durango were dated and the age obtained was 30 ±5 Ma. This date is in agreement with similar results obtained by Fleisher and Naeser (1975) for zircons of the same locality and dated by the

  6. Naturally etched tracks in apatites and the correction of fission track dating

    CERN Document Server

    Tien, J L

    1999-01-01

    Naturally etched tracks have been found in apatites from the rapid cooled, high-level Kunon pluton in the Zhangzhou Igneous Complex, SE China. This is manifested by the fact that the apatite fission track (FT) age derived from conventional counting of spontaneous and induced tracks yields a result of 140.6+-6.5 Ma, which is much older than the ages determined using other methods on different minerals from the same rock. When tracks are observed after etching the polished inner sections of the apatite grains, the naturally etched tracks characterized by having hazy boundaries can be distinguished from the normal tracks with sharp boundaries. The age obtained by omitting these fading-resistant hazy tracks, 76.5+-4.0 Ma, indicates the time of the Kunon pluton cooling down to approx 100 deg. C. The corrected peak age (73.8 Ma) is consistent with the other apatite FT peak ages (79.2 to 70.2 Ma) of the nearly contemporaneous plutons in the same igneous complex.

  7. Disintegration constant of uranium-238 by spontaneous fission redetermined by glass track method

    International Nuclear Information System (INIS)

    Lima Medeiros, E. de.

    1978-01-01

    The disintegration constant of U 238 by spontaneous fission using glass as fission fragment detector was redetermined. A film of natural uranium (UO 3 ) prepared by chemical methods on the glass lamina was used in a long time experience of exposure (about 16 years). The good conditions of sample preparation and storage allow to observe, after chemical etching, fission fragment tracks. (M.C.K.) [pt

  8. Critical angles for fission fragment registrations in some solid state track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, A D; Bahromi, I I; Beresina, N V [AN Uzbekskoj SSR, Tashkent. Inst. Yadernoj Fiziki; and others

    1980-03-01

    In studies of the registration efficiency of various solid state track detectors (polycarbonate, polyethyleneterephthalate, cellulose nitrate and muscovite) the detectors were irradiated with spontaneous fission fragments from /sup 252/Cf and with fission fragments from /sup 235/U separated according to mass and energy. Experimental details are given. Critical angles for the registration of fission fragments in the various detectors are given for specified energies and masses.

  9. Studies on fission tracks and distributions of uranium and rare earths in granite materials

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi; Sakanoue, Masanobu

    1987-01-01

    Many materials contain fossil records of the slow spontaneous fission of uranium they contain as an impurity. Fission fragments, heavy charged particles released in each fission event, produce microscopic trails of radiation damage that may persist over geological times and may be developed to a size observable under an optical microscope by a suitable etching treatment. Such tracks are also produced by fissions induced by thermal neutron irradiation of the uranium. When the material is heated sufficiently, it anneals and the the microscopic trails become shorter and narrower. The track density decreases, because the chemical etchant will not reach some of the shortened tracks. Measurements of track densities before and after annealing can be used, along with laboratory studies of annealing rates, to determine the annealing temperature. Also, the track density of induced fissions is related to the concentration of uranium and the fluence of neutrons to which it was exposed. If the track density due to induced fissions can be distinguished from that due to fossil tracks, estimates of either the concentration or the fluence can be made if the other is known. Two such materials (one a fragment of a granite paving stone, the other a piece of stained glass from a cathedral window) that had been exposed to the atomic bomb at Nagasaki were used in the present work. The fossil record in zircons in the granite was used to estimate the temperature to which it had been exposed in the bombing. Induced fissions were used to estimate the concentration of uranium in the zircons. Nonuniform heating and cooling and nearly uniform exposure to the neutrons make the granite sample unsuitable for determining the neutron fluence from the bomb. Induced fissions in the stained glass were used to estimate the concentration of uranium and the thermal neutron fluence from the A-bomb. Annealing of tracks in glass was also studied

  10. Etching of fission tracks in silicate glasses by means of deionized water

    International Nuclear Information System (INIS)

    Dran, J.C.; Petit, J.C.

    1985-09-01

    Fission tracks have been revealed in silicate glasses with deionized water. Their sharp conical shape implies a marked enhancement of the dissolution rate along their core and consequently a cone angle and an etching efficiency (close to 100%) much higher than previously reported for glasses. We show that etching of fission tracks in natural environments has generally very limited geochemical implications except in specific cases such as that found in the Oklo uranium ores

  11. Fission-track dating of apatite from deep borehole ATK-1 at Atikokan, Ontario

    International Nuclear Information System (INIS)

    Naeser, C.W.; Crowley, K.D.

    1990-01-01

    Fission-track age and lengths have been determined on apatite separated from core recovered from the ATK-1 deep borehole at Atikokan, Ontario. The apatite ages decrease down the borehole, from 515 ± 72 Ma at the top to 376 ± 46 Ma at a depth of 993 m. The mean confined track length for fossil fission tracks in the apatite is 12.4 μm. Within the limits of the measurement the track lengths are the same for all the samples. The results of this study indicate that the rocks found currently at the surface have never been heated above ∼100C since Upper Cambrian time

  12. Apatite fission track dating and thermal history of Qing-He region in Altay Mountains

    International Nuclear Information System (INIS)

    Bao Zengkuan; Chinese Academy of Sciences, Beijing; Yuan Wanming; Dong Jinquan; Gao Shaokai

    2005-01-01

    Fission track ages (FTA) and track lengths of apatite from Qing-He diorite intrusion in Altay Mountains are measured. Apatite fission track ages of three diorite samples is range from (78±5) Ma to (95 ± 5) Ma, and the lengths of horizontal confined spontaneous fission tracks are (13.2 ± 1.2)-(13.5 ±1.3) μm. The distribution of the track length is narrow and symmetrical with a mean length of approximately 13.3 μm and a standard deviation of around 0.1 μm. The inverse modeling results show that thermal history of this region has four stages, two rapid uplift of this region still existed magmatic intrusion and tectonic movements in Yanshanian. (authors)

  13. Studies of isothermal annealing of fission fragment and alpha particle tracks in Cr-39 polymer detectors

    International Nuclear Information System (INIS)

    Zaky, M.F.; Youssef, A.A.

    2002-01-01

    Two groups of CR-39 detectors samples are exposed to two types of charged particle radiation. The first group are severe damaged with fission fragment tracks from 2 52C f source. The second accepted alpha particles resulting from the interaction of highly energetic 1 9F -ions and a copper disk with thickness 1 cm, which are of less damage tracks than fission fragments. , The isothermal annealing of tracks in the temperature range from 175 to 300 degree C in step 25 degree C for annealing time of 10,15,20,25 and 30 minutes has been investigated. The changes introduced in the track density and track diameter for two types of irradiation in the detector have been observed and compared between them. The results indicate that the track density and the size of the tracks are considerably changed due to annealing

  14. Fission distribution measurements of Atucha's fuel pellets with solid state track detectors

    International Nuclear Information System (INIS)

    Ricabarra, M.D. Bovisio de; Waisman, Dina.

    1979-08-01

    Distribution of fissions in a UO 2 rod has been measured by means of solid state detectors. Mica muscovite and Makrofol-N detectors were used in the experiment. The merits of mica muscovite relative to the Makrofol-N for the detection of fission fragments have been verified. However both fission track detectors closely agree (0,5%) in the final fission distribution of the UO 2 rod. Sensitivity of the detectors shows to be linear in the range between 50.000and 360.000 fission tracks per square centimeter. Due to the high spatial resolution this method is better than any other technique. Determination were made in UO 2 pellets similar to the fuel element of the Atucha reactor. The average fission rate in the rod has been measured within 0,8% error, and provides an accurate determination for the distribution of fissions in the rod wich is needed for the determination of energy liberated per fission in the natural uranium rod.(author) [es

  15. Fission track dating method: I. Study of neutron flux uniformity in some irradiation positions of IEA-R1 reactor

    International Nuclear Information System (INIS)

    Osorio, A.M.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R. de

    1993-06-01

    In order to use the fission track dating method the flux gradient was verified within the sample holder, in some irradiation positions of the IEA-R1 reactor at IPEN/CNEN, Sao Paulo. The fission track dating method considers only the thermal neutron fission tracks, to subtract the other contributions sample irradiations with a cadmium cover was performed. The neutron flux cadmium influence was studied. (author)

  16. Interaction of Tim23 with Tim50 Is essential for protein translocation by the mitochondrial TIM23 complex.

    Science.gov (United States)

    Gevorkyan-Airapetov, Lada; Zohary, Keren; Popov-Celeketic, Dusan; Mapa, Koyeli; Hell, Kai; Neupert, Walter; Azem, Abdussalam; Mokranjac, Dejana

    2009-02-20

    The TIM23 complex is the major translocase of the mitochondrial inner membrane responsible for the import of essentially all matrix proteins and a number of inner membrane proteins. Tim23 and Tim50, two essential proteins of the complex, expose conserved domains into the intermembrane space that interact with each other. Here, we describe in vitro reconstitution of this interaction using recombinantly expressed and purified intermembrane space domains of Tim50 and Tim23. We established two independent methods, chemical cross-linking and surface plasmon resonance, to track their interaction. In addition, we identified mutations in Tim23 that abolish its interaction with Tim50 in vitro. These mutations also destabilized the interaction between the two proteins in vivo, leading to defective import of preproteins via the TIM23 complex and to cell death at higher temperatures. This is the first study to describe the reconstitution of the Tim50-Tim23 interaction in vitro and to identify specific residues of Tim23 that are vital for the interaction with Tim50.

  17. Fission track thermochronology : reconstructing the thermal and tectonic evolution of the crust

    International Nuclear Information System (INIS)

    Gleadow, A.J.W.

    1990-01-01

    The basis and current status of fission track analysis is reviewed showing the kinds of patterns of fission track parameters which result from a variety of thermal and tectonic histories. Fission track thermochronology is a well established method for reconstructing the thermal histories of rocks with particularly important applications in tectonic studies. Quantitative modelling of the thermal annealing of tracks in apatite shows that distinctive profiles of apparent fission track age can be related to a number of simple thermal history styles. The main types of profiles observed tend to be either an essentially linear decrease of apparent age with increasing depth, which relates to continuous uplift and denudation, or a concave-upwards profile produced by partial annealing in environments of tectonic stability or burial. More complex thermal histories produce compound profiles which are essentially just combinations of these two elements. Track length information allows the apparent age profiles to be interpreted in much greater detail. Examples of the major profile types have been identified in various geological environments and can be analysed to give information about, for example, uplift and denudation rates, the timing of uplift or low-grade thermal events and maximum palaeotemperatures experienced during burial. 25 refs., 8 figs

  18. Characterization of aerosols containing fissionable elements using solid-state track recorders

    International Nuclear Information System (INIS)

    Roberts, J.H.; Kafalenos, V.P.; Yule, T.J.

    1976-01-01

    An aerosol of U 3 O 3 highly enriched in 235 U was generated with a nebulizer from a suspension of U 3 O 8 powder in distilled water. The aerosol was collected on a membrane filter. Polycarbonate plastic, placed in good contact with the filter, was used to record fission tracks when the package was exposed to known fluences of slow neutrons. Fission-track stars associated with individual particles of U 3 O 8 were observed in the plastic. The fission-track distributions were converted to a particle size distribution for the aerosol. For a log normal distribution the geometric mean and standard deviation can be determined with better than 5% accuracy. This method can be applied to plutonium and other transuranic aerosols. (orig.) [de

  19. Determination of the uranium concentration in soil solutions by the fission track registration technique

    International Nuclear Information System (INIS)

    Fernandes, G.P.

    1980-02-01

    The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

  20. The quantitative determination of uranium in human hair by fission track measurements

    International Nuclear Information System (INIS)

    Wilson, D.J.; Bentley, K.W.

    1985-01-01

    Human hairs containing a uranium burden were placed in contact with a mica sheet as the recording matrix and irradiated in a thermal neutron flux. The fission fragment tracks penetrating the mica were etched and counted. Calculations have been made to show the losses due to the fission fragment range being less than the diameter of the hair and for the variation of track density with distance from the line of contact between the hair and the mica. Experimental data from 50 μm diameter hair and those derived by calculation were compared. (author)

  1. Obsidian dating by fission track method; Datacao de obsidianas com o metodo dos tracos de fissao

    Energy Technology Data Exchange (ETDEWEB)

    Araya, A M.O.

    1990-12-01

    The fission track method was employed to obtain the age of twelve obsidian sample from Ecuador. By using the plateau-age correction method, we obtained the true age of each sample and were able to identify four groups of ages in the studied area. Thereafter we studied the fading of fission tracks in two obsidian samples with different origins: Yanaurcu, Ecuador and Monte Arci, Italy. We constructed Arrhenius plots and calculated activation energies for both samples. The results from thermal annealing experiments were compared with theoretical curves obtained by integrating an equation proposed by Shukolyukov et al (1965). (author). 43 refs, 20 figs, 10 tabs.

  2. A numerical model for the thermal history of rocks based on confined horizontal fission tracks

    DEFF Research Database (Denmark)

    Jensen, Peter Klint; Hansen, Kirsten; Kunzendorf, Helmar

    1992-01-01

    A numerical model for determination of the thermal history of rocks is presented. It is shown that the thermal history may be uniquely determined as a piece-by-piece linear function on the basis of etched confined, horizontal fission track length distributions, their surface densities, and the ur......A numerical model for determination of the thermal history of rocks is presented. It is shown that the thermal history may be uniquely determined as a piece-by-piece linear function on the basis of etched confined, horizontal fission track length distributions, their surface densities...

  3. Solid State Track Recorder fission rate measurements at high neutron fluence and high temperature

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Roberts, J.H.; Gold, R.

    1985-01-01

    Solid State Track Recorder (SSTR) techniques have been used to measure 239-Pu, 235-U, and 237-Np fission rates for total neutron fluences approaching 5 x 10 17 n/cm 2 at temperatures in the range 680 to 830 0 F. Natural quartz crystal SSTRs were used to withstand the high temperature environment and ultra low-mass fissionable deposits of the three isotopes were required to yield scannable track densities at the high neutron fluences. The results of these high temperature, high neutron fluence measurements are reported

  4. Determination in soils of soluble uranium fraction in acid medium by fission tracks registration techniques

    International Nuclear Information System (INIS)

    Fernandes, G.P.

    1980-01-01

    The fission tracks registration technique was used to determine the concentration of uranium in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. The method was applied to a few samples of soils from Pocos de Caldas, Minas Gerais in Brazil. The concentrations of uranium in the samples and residues were also determined by other methods to compare the results obtained; only one sample showed deviation among the results obtained by the fission tracks method. (author)

  5. Tracking of fission products release during refueling operations

    International Nuclear Information System (INIS)

    Agarwal, Sharad; Prajapat, M.K.; Vyas, Shyam; Hussain, S.A.

    2001-01-01

    It has been always observed that the release of fission products increase during refueling operations. At RAPP-3 and 4 an attempt has been made to follow-up the change in fission products activity release at each stage of refueling operation and quantification of concentrations of various radionuclides. This exercise was also extended to refueling operation of the channels containing suspected failed fuel. A level of FPNG ( 133 Xe) was observed to increase by a factor of about 10-40 during refueling of failed channel as compared to healthy channel. It can be concluded that by monitoring FPNG levels in exhaust status of the healthiness of spent fuel can be found out. This report discusses in detail the experiment conducted for this purpose. (author)

  6. Induced fission track distribution from highly radioactive particles in fallout materials

    International Nuclear Information System (INIS)

    Hashimoto, Tetsuo; Okada, Tatemichi

    1987-01-01

    Some highly radioactive fallout particles (GPs) from the 19th Chinese nuclear detonation were followed to the neutron irradiation in a reactor after sandwiched with mica detectors. The interesting star-like fission track patterns were revealed on the etched surface of the mica detectors. The simple chemical separation procedure for the GPs was applied for the separation of U and Pu as fissile elements and the both resultant fractions were examined with the similar high sensitive fission tracking detection. Subsequently, a representative track pattern from a black spherical particle was subjected to the determination of fissile nuclide content; comparing the total fission events evaluated on the basis of the numerical calculation of track densities with the total thermal neutron fluence. The results implied that the uranium is responsible for the main fissile nuclide remaining within a particle as unfissioned fractions and should be certainly enriched with respect to U-235 within such small fallout particles. This sophisticated method was also applied to determine the dead GPs, which have been highly radioactive particles just after the detonations, in the rain and snow-residual materials. Many induced star-like fission tracks verified certainly that there remains a lot of dead particles in the atmosheric environment till nowadays. (author)

  7. The thermal history of the Bowen Basin: a comparison of apatite fission track analysis and vitrinite reflectance

    International Nuclear Information System (INIS)

    Marshallsea, S.J.

    1987-01-01

    Vitrinite reflectance and apatite fission-track analysis (AFTA) are two techiques widely used to assess paleotemperatures of the order of 20-120 deg.C. in sedimentary basins. Whereas vitrinite reflectance is essentially a qualitative technique that gives an integrated measure of the entire thermal history, AFTA can reveal information on the variation of paleotemperatures through time because fission-tracks in apatite are continually produced throughout geological time. An apatite fission track study of the Upper Permian units of the Bowen Basin has offered the opportunity to compare the two paleotemperature indicators and place constraints on the timing of maximum paleotemperatures. The regional pattern of apatite fission-track ages closely coincides with the vitrinite reflectance indicating that maximum paleotemperatures have varied across the Basin with the central region of the Bowen Basin experiencing highest paleotemperatures. The reduction in apatite reflectance fission-track age with increasing reflectance represents the progressive annealing at temperatures around 60-120 deg. C. of those fission-tracks formed prior to the time of maximum temperatures. In those samples giving the youngest apatite fission-track ages all tacks were totally annealed at this time, and the fission-track age in these samples, in the range 90-120 Myr, indicate the time of cooling from the thermal maximum in the Early Cretaceous. 1 ref

  8. Detection of fission fragments using thick samples in contact with solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Lima, D.A. de; Martins, J.B.; Tavares, O.A.P.

    1987-01-01

    Whenever use is made of thick samples in contact with solid state nuclear track detectors for determining fission yields, one of the fundamental problems is the evaluation of the effective number of target nuclei which contributes to the fraction of the number of fission events that will be recorded. The evaluation of the effective number of target nuclei which contributes to recorded events is based on the effective thickness of the sample. A method for evaluating effective thickness of thick samples for binary fission modes, is presented. A cross section equation which takes into account all the necessary corrections due to fragment attenuation effects by a thick target for calculation induced fission yields, was obtained. (Author) [pt

  9. Fission track dating and thermal history of Habahe rock body in Altai

    International Nuclear Information System (INIS)

    Liu Shunsheng; Tan Kaixuan

    2002-01-01

    The fission track ages (FTA) of several apatite and zircon samples from Habahe rock body in Altai were determined. The FTA of apatites were 51.1-76.9 Ma, and FTA of zircons were 141-149 Ma. Modelling of the palaeo-temperature evolution [T(t)-path] of rock body relies on confined track length measurements and the annealing equations of Laslett et al. (1987). The thermal and uplift history of this region was discussed

  10. Thorium content of a mineral ore from Morro do Ferro by fission track technique

    International Nuclear Information System (INIS)

    Oliveira, C.A.N. de.

    1980-10-01

    The feasibility to determine thorium concentrations by fission track technique in samples of mineral ore has been demonstrated. The literature registers only the application of the fission track technique to mineral ore in the case where the fissionable element is uranium. The technique was applied to determine the thorium concentration of an ore sample from Morro do Ferro, taking advantage of the high thorium to uranium ratio in that mineral. The sample analysed presented a thorium concentration of 2467 +- 400 mg Th/Kg ore. The so called wet method was adopted by using the Bayer made Makrofol KG 10μm thick, as the detector foil, immersed in the thorium solution. The technique is also useful to determine thorium concentrations in environmental samples because of the following aspects: high sensitivity; fast chemical separation of interfering elements; low cost; and operational simplicity. (Author) [pt

  11. A fission track technique used for hydrogeochemical prospecting in Northern India

    International Nuclear Information System (INIS)

    Singh, N.P.; Singh, S.; Virk, H.S.

    1988-01-01

    A fission track technique is employed to determine the uranium content of water samples collected from different locations of the middle and outer Himalayas. The regional threshold for the uranium content is determined for water samples of different areas. The identification of anomalies in an area of uranium mineralization confirmed that the hydrogeochemical technique could successfully be used for uranium exploration. (author)

  12. Estimation of U content in coffee samples by fission-track counting

    International Nuclear Information System (INIS)

    Sharma, P.K.; Lal, N.; Nagpaul, K.K.

    1985-01-01

    Because coffee is consumed in large quantities by humans, the authors undertook the study of the uranium content of coffee as a continuation of earlier work to estimate the U content of foodstuffs. Since literature on this subject is scarce, they decided to use the well-established fission-track-counting technique to determine the U content of coffee

  13. Fission track dating and uranium estimation in pegmatitic minerals of Rajasthan state (India)

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S; Virk, H S [Punjabi Univ., Patiala (India). Dept. of Physics

    1978-12-01

    Fission track geochronology of muscovite samples collected from some pegmatitic mines of Bhilwara and Ajmer districts of Rajasthan state (India) has been discussed. The ages obtained suggest the occurrence of Delhi Orogenic Cycle as the last major metamorphic activity in the region. The atomic fraction of uranium in muscovite samples is less than 1 p.p.b.

  14. Dating by fission tracks in archaeology. 2. Characterization and dating of obsidian artefact

    International Nuclear Information System (INIS)

    Poupeau, G.; Zuleta, E.

    1984-01-01

    The ways of obsidian characterization presently used in archaeology are presented. The possibilities of the fission track method are more specially discussed, with two examples of works done in Japan and on any samples of andine America. (L.C.) [pt

  15. Fission-track evidence of tectonic evolution in the northwestern Qaidam Basin, China

    Science.gov (United States)

    Sun, Guo-Qiang; Liu, Wei-Ming; Guo, Jia-Jia; Wang, Ye-Tong

    2018-02-01

    Fission-track dating was conducted on zircons and apatites from 11 cores of the upper Xiaganchaigou Formation and lower Shangganchaigou Formation (northwestern Qaidam Basin). The obtained apatite fission-track age is 3.1-61.9 Ma, and the zircon fission-track age is 49.2-123.5 Ma. Although the average apatite age is consistent with ages predicted from the stratigraphy, nine of the 11 apatite fission-track ages have P(χ2) 5%, exhibiting consistent characteristics and indicating that zircons retain provenance age information after burial. From the zircon and apatite ages, the fission-track length distribution, and the geological setting, the northwestern Qaidam Basin has experienced two tectonothermal events since the Late Mesozoic, at 39.1 ± 9.3 to 133.7 ± 6.6 Ma and 1.2 ± 0.6 to 32.0 ± 3.0 Ma. The earlier (39.1-133.7 Ma) tectonothermal event resulted from the initial collision of the Indian and Eurasian plates. As a consequence of the collision, the Altyn Tagh fault, which forms the northwestern boundary of the Qaidam Basin, began to develop. Subsequently, uplift of the Altyn Tagh mountains began and the northwestern depression of the Qaidam Basin started to form. The later (1.2-32.0 Ma) tectonothermal event resulted from further collision of the Indian and Eurasian plates along the Yarlung Tsangpo suture zone. Strata in the Qaidam Basin were further deformed by transpression in this period and this period played a crucial role in petroleum accumulation.

  16. A note on frequency distributions of fission tracks in apatite

    International Nuclear Information System (INIS)

    He, Z.; Lerche, I.

    1989-01-01

    Two different formulae, both purportedly describing track length reduction in apatite, are converted to forms useful in prediction of track length distributions along sedimentary burial history paths. Using the formalism, track length distribution data from four NW Canning Basin wells are inverted to determine the physical (chemical) parameters associated with the models as well as the heat flux variation with time. For each formula the resulting physical parameters are consistent among the wells tested but differ from laboratory-derived parameter values, and the thermal histories are consistent with those inferred from geological data. Comparison of the two models shows no evidence that one model should be favored over the other based on the data available. It is also shown that the resolution of the parameters is dependent not only on the quantity of the data but also on the ''quality'' -explicitly upon the variation and distribution with depth. (author)

  17. Fission track astrology of three Apollo 14 gas-rich breccias

    Science.gov (United States)

    Graf, H.; Shirck, J.; Sun, S.; Walker, R.

    1973-01-01

    The three Apollo 14 breccias 14301, 14313, and 14318 all show fission xenon due to the decay of Pu-244. To investigate possible in situ production of the fission gas, an analysis was made of the U-distribution in these three breccias. The major amount of the U lies in glass clasts and in matrix material and no more than 25% occurs in distinct high-U minerals. The U-distribution of each breccia is discussed in detail. Whitlockite grains in breccias 14301 and 14318 found with the U-mapping were etched and analyzed for fission tracks. The excess track densities are much smaller than indicated by the Xe-excess. Because of a preirradiation history documented by very high track densities in feldspar grains, however, it is impossible to attribute the excess tracks to the decay of Pu-244. A modified track method has been developed for measuring average U-concentrations in samples containing a heterogeneous distribution of U in the form of small high-U minerals. The method is briefly discussed, and results for the rocks 14301, 14313, 14318, 68815, 15595, and the soil 64421 are given.

  18. Uranium fission track length distribution modelling for retracing chronothermometrical history of minerals

    International Nuclear Information System (INIS)

    Rebetez, M.

    1987-01-01

    Spontaneous fission of uranium 238 isotope contained in certain minerals creates damage zones called latent tracks, that can be etched chemically. The observation of these etched tracks and the measurement of their characteristics using an optical microscope are the basis of several applications in the domain of the earth sciences. First, the determination of their densities permits dating a mineral and establishing uranium mapping of rocks. Second, the measurement of their lengths can be a good source of information for retracing the thermal and tectonic history of the sample. The study of the partial annealing of tracks in apatite appears to be the ideal indicator for the evaluation of petroleum potential of a sedimentary basin. To allow the development of this application, it is necessary to devise a theoretical model of track length distributions. The model which is proposed takes into account the most realistic hypotheses concerning registration, etching and observation of tracks. The characteristics of surface tracks (projected lengths, depths, inclination angles, real lengths) and confined tracks (Track IN Track and Track IN Cleavage) are calculated. Surface tracks and confined tracks are perfectly complementary for chrono-thermometric interpretation of complex geological histories. The method is applied to the case of two samples with different tectonic history, issued from the cretaceous alcalin magmatism from the Pyrenees (Bilbao, Spain). A graphic method of distribution deconvolution is proposed. Finally, the uranium migration, depending on the hydrothermal alteration, is studied on the granite from Auriat (France) [fr

  19. Estimation of trace levels of plutonium in urine samples by fission track technique

    International Nuclear Information System (INIS)

    Sawant, P.D.; Prabhu, S.; Pendharkar, K.A.; Kalsi, P.C.

    2009-01-01

    Individual monitoring of radiation workers handling Pu in various nuclear installations requires the detection of trace levels of plutonium in bioassay samples. It is necessary to develop methods that can detect urinary excretion of Pu in fraction of mBq range. Therefore, a sensitive method such as fission track analysis has been developed for the measurement of trace levels of Pu in bioassay samples. In this technique, chemically separated plutonium from the sample and a Pu standard were electrodeposited on planchettes and covered with Lexan solid state nuclear track detector (SSNTD) and irradiated with thermal neutrons in APSARA reactor of Bhabha Atomic Research Centre, India. The fission track densities in the Lexan films of the sample and the standard were used to calculate the amount of Pu in the sample. The minimum amount of Pu that can be analyzed by this method using doubly distilled electronic grade (E. G.) reagents is about 12 μBq/L. (author)

  20. Technique of neutron-induced (fission-track) autoradiography with histological detail

    International Nuclear Information System (INIS)

    Smith, J.M.; Taylor, G.N.; Jee, W.S.S.

    1980-01-01

    The primary advantage of neutron-induced or fission-track autoradiography compared with conventional autoradiography is that for low concentrations of fissile nuclides prohibitively long exposure times may be avoided. However, it is difficult to produce imaging of biological structures on the neutron-induced autoradiograph which would allow localization of the nuclide histologically. The technique presented circumvents this difficulty using a thin polycarbonate film applied to the histologically stained tissue section mounted on a quartz substrate. After irradiation of the tissue section with an appropriate thermal neutron flux, the fission fragment tracks are revealed by etching the film with KOH. The tracks, superimposed on the stained tissue, may be observed under the light microscope in the same manner as for conventional nuclear emulsion autoradiography

  1. Experimental examination of ternary fission in nuclear track emulsion

    Czech Academy of Sciences Publication Activity Database

    Mamatkulov, K. Z.; Ambrožová, Iva; Artemenkov, D. A.; Bradnova, V.; Firu, E.; Haiduc, M.; Kákona, Martin; Kattabekov, R. R.; Marey, A.; Neagu, A.; Ploc, Ondřej; Rusakova, V. V.; Stanoeva, R.; Turek, Karel; Zaitsev, A. A.; Zarubin, P. I.; Zarubina, I. G.

    2017-01-01

    Roč. 48, č. 6 (2017), s. 910-913 ISSN 1063-7796 Institutional support: RVO:61389005 Keywords : angular correlation * nuclear track emulsion Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 0.681, year: 2016

  2. Measurement of uranium in human teeth and kidney stones with the fission track technique

    International Nuclear Information System (INIS)

    Vartanian, R.

    1986-01-01

    The measurement of uranium in human teeth and in kidney stones was carried out using the fission track activation technique. In this determination 2759 and 2205 absolute counts of tracks for teeth samples and 1689 tracks for kidney stone samples were performed, respectively. The results are as follows: xsub(tooth) (1)=(0.227+-0.006) ppm, xsub(tooth) (2)=(0.143+-0.007) ppm and xsub(kidney)=(0.568+-0.020) ppm. The experimental method is described and the results are discussed. (author)

  3. Observations of fission-tracks in zircons by atomic force microscope

    International Nuclear Information System (INIS)

    Ohishi, Shinnosuke; Hasebe, Noriko

    2012-01-01

    The fission-track (FT) method is a dating technique based on the observation of damage (tracks) by spontaneous fission of 238 U left in a mineral. The date is calculated from the track density and the uranium concentration in the mineral. This is possible because the number of tracks is a function of uranium concentration and time since the start of track accumulation. Usually, the number of tracks is counted under an optical microscope after etching (chemical expansion of a track). However, as FT density per unit area rises, it becomes difficult to count the number of tracks. This is due to the fact that FTs overlap one another and are unable to be readily distinguished. This research examines the potential of atomic force microscope (AFM) for FT dating using zircons, which are likely to show higher FT density than other minerals due to their high U concentrations. To obtain an AFM image for a sample prepared for FT dating, removing the static electricity of the sample is essential to avoid an unexpected movement of the cantilever. A grain should be wider than about 30 μm to bring the cantilever on the mineral surface. Polishing with a fine grained compound is very important. There is not much difference in sharpness between images by AC mode (scanning with vibrating cantilever at a constant cycle) and Contact mode (scanning with the cantilever always in close contact with the surface). To confirm how tracks can be identified with the AFM, an AFM image was compared with an image obtained with the optical microscope. When change in the number of tracks and their shapes were observed through stepwise etching, the track expanded as the etching time increased. In addition, the etching rate was slower for large tracks than those for small tracks. This implied that the AFM can be used to observe etching of zircons with different degrees of nuclear fission damage. A track that could not be seen with the optical microscope due to insufficient etching could be observed by

  4. Fission track dating: methodology and thermo-chronological applications in alpine and continental margin contexts

    International Nuclear Information System (INIS)

    Sabil, N.

    1995-06-01

    The fission track dating method has proved to be unique in thermo-chronology by its capability to describe the final phases of the cooling history and denudation of metamorphic massifs, like the thermal history of sedimentary formations or the dating of some volcanic materials. In this work we describe this method and present a series of new analytic techniques and calibrations which we realised in the aim of further use in geology. We discuss a few examples of such applications. In the french Occidental Alps, the analysis of fission track on apatite samples from the granites of the Sept Laux (Belledonne massif), in the Eau d' Olle valley, suggests that this method could bring a contribution to the actual discussion about the origin of some alpine valleys. The fission track method suggests that the opening of this valley could be the consequence of an active faulting from the middle Miocene until the present. The characterization of fluvial deposits through their detrital apatites fission tracks record could eventually be used to study river captures related to changes tectonic regimes. Therefore we studied the apatites of a paleo-delta located in the Isere middle valley at the sub-alpine 'sillon' level, and of two valleys, those of the Arc and of the Breda, located up the delta. The distribution of the fission track ages of those mineraIs has not confirmed a previously suggested model, which proposed that the studied paleo-delta could be associated with a paleo-Arc rather than a paleo-Breda. In the Moroccan Occidental Meseta, three granitic massifs located in the Rehamna have been selected for a thermo-chronological study. The analysis of the fission track in zircons and apatites of these granites recorded the thermo-tectonic events which have affected the Meseta ever since the opening of the Central Atlantic Ocean some 200 Ma ago. We show how a numerical simulation model recently (1994) proposed for the analysis of fission track in apatites allows us to specify

  5. Contribution of the fission-track method to the study of the Alpine chains: relationship between tectonics and metamorphism

    International Nuclear Information System (INIS)

    Carpena, J.

    1984-01-01

    The fission-track method allows geologists to date rocks and to get information on the thermal history of rocks. Fission tracks in minerals are essentially due to the spontaneous fission of uranium 238. The knowledge of the density of tracks and the concentration of uranium 238 lead to the determination of the age of the rock. The irradiation in a neutron flux of a sample of the rock allows the determination of the concentration of uranium. The age obtained is in fact an apparent age that does not take into account possible geological annealing process that may erase fission tracks, some corrections are then necessary. The first part of this work details the fission-track method, its scope and limitations. It is shown that fission-track method on apatites can reveal the thermal evolution of the rock and that the same method used on zircons can give information of the setting of volcanic rocks. The second part is dedicated to the contribution of the fission-track method to a both dating and thermal evolution study of a french-italian part of the Alpine chain

  6. On the frequency distributions per unit area of the projected and etchable lengths of surface-intersecting fission tracks: influences of track revelation, observation and measurement

    International Nuclear Information System (INIS)

    Jonckheere, R.; Haute, P. van den

    1999-01-01

    In addition to the statistical bounds discussed, thermal history analysis based on the projected and etchable length distributions of surface intersecting fission tracks is limited by systematic factors related to track revelation, observation and measurement. The effects of track revelation, in particular, distort these distributions in the length intervals of interest. An observation threshold poses a problem if it is described by a critical angle θ c , but not if it is described by other criteria proposed in the literature. Measurement imprecisions, predictably, blur the thermal history information contained in these distributions. Measurements of semi-confined tracks, added as a result of surface etching, are a more promising alternative to confined track length measurements for accessing the thermal history record in the fission track length distribution. On the other hand, measurements of the projected lengths of surface intersecting tracks offer the theoretical possibility of determining the true volumetric density N and true mean length m of an arbitrary population of fission tracks, thus allowing direct determination of the corrected age of samples with complex thermal histories. On a methodical level, knowledge of N and m allows to determine the efficiency with which fission tracks are counted under the optical microscope under exactly the same conditions as those under which fission track counts for routine dating purposes are performed

  7. Irradiation positions for fission-track dating in the University of Pavia TRIGA Mark II nuclear reactor

    International Nuclear Information System (INIS)

    Oddone, Massimo; Meloni, Sandro; Balestrieri, Maria Laura; Bigazzi, Giulio

    2002-01-01

    An irradiation position arranged is described in the present paper for fission-track dating in the Triga Mark II reactor of the University of Pavia. Fluence values determined using the NIST glass standard SRM 962a for fission-track dating and the traditional metal foils are compared. Relatively good neutron thermalization (φ th /φ f = 0.956) and lack of significant fluence spatial gradients are good factors for fission-track dating. Finally, international age standards (or putative age standards) irradiated in this new position yielded results consistent with independent reference ages. (author)

  8. U and Th thin film neutron dosimetry for fission-track dating: application to the age standard Moldavite

    International Nuclear Information System (INIS)

    Iunes, P.J.; Bigazzi, G.; Hadler Neto, J.C.; Laurenzi, M.A.; Balestrieri, M.L.; Norelli, P.; Osorio Araya, A.M.; Guedes, S.; Tello S, C.A.; Paulo, S.R.; Moreira, P.A.F.P.; Palissari, R.; Curvo, E.A.C.

    2005-01-01

    Neutron dosimetry based on U and Th thin films was used for fission-track dating of the age standard Moldavite, the central European tektite, from the Middle Miocene deposit of Jankov (southern Bohemia, Czech Republic). Our fission-track age (13.98+/-0.58Ma) agrees with a recent 40 Ar/ 39 Ar age, 14.34+/-0.04Ma, based on several determinations on Moldavites from different sediments, including the Jankov deposit. This result indicates that the U and Th thin film neutron dosimetry represents a reliable alternative for an absolute approach in fission-track dating

  9. A numerical model for the thermal history of rocks based on confined horizontal fission tracks

    International Nuclear Information System (INIS)

    Jensen, P.K.; Kunzendorf, Helmar; Hansen, Kirsten

    1992-01-01

    A numerical model for determination of the thermal history of rocks is presented. It is shown that the thermal history may be uniquely determined as a piece-by-piece linear function on the basis of etched confined, horizontal fission track length distributions, their surface densities, and the uranium content. The initial track length distribution is taken into account. A relation between the measured track length distribution and age is given which includes correction for partial annealing. The annealing model used is the fanning Arrhenius plot. It is shown that track length distributions measured in transmitted light are biased favouring short tracks compared with measurements in reflected light. Testing of the model is performed on apatites from a tuffaceous sandstone from Bornholm (Denmark) yielding an estimate of the thermal history for the period of about 280 Ma back in time. (author)

  10. Liquid nitrogen enhancement of partially annealed fission tracks in glass; and reply

    International Nuclear Information System (INIS)

    Wagner, G.A.; Carpenter, B.S.; Pilione, L.J.; Gold, D.P.

    1977-01-01

    Pilione and Gold (Nature 262: 773 (1976)) stated that it was possible to reveal partially annealed fission tracks in glass by immersion in liquid N 2 , and that it was possible to increase the total number of etchable tracks by increasing the immersion time. The present authors attempted to duplicate the work of the former authors using the same glass. They found no significant change in the number of etchable tracks after immersion in liquid N 2 , and they concluded that the latter has no effect on annealed tracks in glass. Any observed enhancement of partially annealed tracks is probably a surface effect and has no effect on the interior matrix of the glass. A reply by Pilione and Gold is appended. (U.K.)

  11. LENMODEL: A forward model for calculating length distributions and fission-track ages in apatite

    Science.gov (United States)

    Crowley, Kevin D.

    1993-05-01

    The program LENMODEL is a forward model for annealing of fission tracks in apatite. It provides estimates of the track-length distribution, fission-track age, and areal track density for any user-supplied thermal history. The program approximates the thermal history, in which temperature is represented as a continuous function of time, by a series of isothermal steps of various durations. Equations describing the production of tracks as a function of time and annealing of tracks as a function of time and temperature are solved for each step. The step calculations are summed to obtain estimates for the entire thermal history. Computational efficiency is maximized by performing the step calculations backwards in model time. The program incorporates an intuitive and easy-to-use graphical interface. Thermal history is input to the program using a mouse. Model options are specified by selecting context-sensitive commands from a bar menu. The program allows for considerable selection of equations and parameters used in the calculations. The program was written for PC-compatible computers running DOS TM 3.0 and above (and Windows TM 3.0 or above) with VGA or SVGA graphics and a Microsoft TM-compatible mouse. Single copies of a runtime version of the program are available from the author by written request as explained in the last section of this paper.

  12. Application of fission track detectors to californium-252 neutron dosimetry in tissue near the radiation source

    International Nuclear Information System (INIS)

    Oswald, R.A.; Lanzl, L.H.; Rozenfeld, M.

    1981-01-01

    Fission track detectors were applied to a unique problem in neutron dosimetry. Measurements of neutron doses were required at locations within a tumor of 1 cm diameter implanted on the back of a mouse and surrounded by a square array of four 252 Cf medical sources. Measurements made in a tissue-equivalent mouse phantom showed that the neutron dose rate to the center of the tumor was 2.18 rads mg -1 h -1 +- 8.4%. The spatial variation of neutron dose to the tumor ranged from 1.88 to 2.55 rads mg -1 h -1 . These measurements agree with calculated values of neutron dose to those locations in the phantom. Fission track detectors have been found to be a reliable tool for neutron dosimetry for geometries in which one wishes to know neutron dose values which may vary considerably over distances of 1 cm or less

  13. Application of fission track detectors to californium-252 neutron dosimetry in tissue near the radiation source

    International Nuclear Information System (INIS)

    Oswald, R.A.; Lanzl, L.H.; Rozenfeld, M.

    1981-01-01

    Fission track detectors were applied to a unique problem in neutron dosimetry. Measurements of neutron doses were required at locations within a tumor of 1 cm diameter implanted on the back of a mouse and surrounded by a square array of four 252 Cf medical sources. Measurements made in a tissue-equivalent mouse phantom showed that the neutron dose rate to the center of the tumor was 2.18 rads micrograms-1 h-1 +/- 8.4%. The spatial variation of neutron dose to the tumor ranged from 1.88 to 2.55 rads micrograms-1 h-1. These measurements agree with calculated values of neutron dose to those locations in the phantom. Fission track detectors have been found to be a reliable tool for neutron dosimetry for geometries in which one wishes to know neutron dose values which may vary considerably over distances of 1 cm or less

  14. Apatite fission track evidence on the uplifting of eastern Kunlun mountains

    International Nuclear Information System (INIS)

    Yuang Wanming; Dong Jinquan; Tang Yunhui; Wang Shicheng

    2004-01-01

    A series of samples were collected from about south-north section through Buqingshan and Dulan, eastern Kunlun mountains, China. The 41 apatite fission track ages (FTA) of these samples lie between 25.2 and 130.4 Ma, all of the apatite fission track ages are significantly younger than the host rocks. There are similar evolution trends for Middle-Kunlun zone and North-Kunlun zone, i.e. the FTA becomes less with slow increase of elevations and their uplifting rates are about 2.22 m/Ma. Differently, the FTA in South-Kunlun zone positively correlates to elevation, decreasing 11 m/Ma. It may be shown that South-Kunlun fault play a different and/or more important role on incontinent evolution than Middle-Kunlun fault. (author)

  15. Apatite fission-track dating of erosion in the eastern Andes, Bolivia

    International Nuclear Information System (INIS)

    Crough, S.T.

    1983-01-01

    Three samples from a Triassic-age batholith in the eastern Andes northeast of La Paz, Bolivia yield apatitic fission-track ages of 11-13 Ma. Interpreting these young ages as due to uplift and erosion requires approximately 2.5-5.0 km of erosion in the past 12 Ma, an amount which is consistent with the known geology and which is typical of many active mountain ranges. (orig.)

  16. Fission track ages and uranium concentration of apatites of different rocks of South India

    International Nuclear Information System (INIS)

    Nand Lal; Nagpaul, K.K.; Nagpal, M.K.

    1975-01-01

    The uranium concentration and ages of apatite grains of various rocks of South India have been measured by fission track technique. The ages range from 100 m.y. to 730 m.y. whereas uranium concentrations vary from 0.5 to 23.8 atom/million atoms of the apatite mineral. The ages agree well with the Deccan volcanic and Ocean Cycle activities. (author)

  17. Use of fission track for deciphering the dissolution mechanism of silicates glasses

    International Nuclear Information System (INIS)

    Petit, J.C.; Brousse, C.

    1985-09-01

    Polished sections of silicate glasses containing latent or pre-etched fission tracks have been subjected to corrosion in deionized water or NaCl brines at 20, 50 and 100 0 C. The evolution of glass surface helps deciphering among reported dissolution models. We show that ion-exchange is dominant in simple glasses while in complex ones, dissolution involves several steps including an in-situ transformation of the pristine material and a reprecipitation of dissolved species

  18. Radiation damage studies of mineral apatite, using fission tracks and thermoluminescence techniques

    International Nuclear Information System (INIS)

    Al-Khalifa, I.J.M.

    1988-01-01

    In a uranium (/thorium)-rich mineral sample which has not suffered a recent geological high-temperature excursion, the fossil fission track density (FFTD) will give a good indication of its natural radiation damage, provided that its U/Th ratio is known. From our studies of FFTD and thermoluminescence (TL) properties of several samples of apatite from different locations, and containing varying degrees of natural-radiation damage, an anti-correlation is observed between FFTD and TL sensitivity. It is also found that an anti-correlation exists between TL sensitivity and the amount of damage produced artificially by bombarding apatite crystals with different fluences of ∼30 MeV α-particles from a cyclotron. These results indicate that the presence of radiation damage in this mineral (viz., fluorapatite) can severely affect its TL sensitivity (i.e. TL output per unit test dose). The effect of crystal composition on the thermoluminescence and fission track annealing properties of mineral apatite is also reported. We have found that fission track annealing sensitivity and TL sensitivity are both significantly lower in samples of chlorapatite than in samples consisting predominantly of fluorapatite. (author)

  19. Natural uranium impurities in fission track detectors and associated geocronological parameters

    International Nuclear Information System (INIS)

    Ricabarra, G.H.; Bovisio de Ricabarra, M.D.; Waisman, Dina; Faradjie de Turjanski, Rosa

    1981-01-01

    A technique, based in counting neutron induced fission tracks, has been developed for the measurement of uranium impurities in mica. Uranium concentrations of 10 -10 and 10 -9 (U atom/mica atom) have been measured. As a part of the development of this technique, the mica geological age was also measured, by fossil and induced track detection. The agreement obtained by this method, T = (472+-52) x 10 6 years with that of (450+-15) x 10 6 years obtained by the Ar-K technique is satisfactory and is an indirect test of the fission track technique used. A careful analysis of the neutron field parameters and nuclear data used in the age determination was made. This analysis is useful for applications in geocronology. According to this analysis a value of lambdasub(f)=(7.1+-0.1) x 10 -17 years -1 is recommended for the spontaneous fission of U238. However, in order to compare the results, the quoted age, T=(472+-52) x 10 6 years, was obtained with the generally accepted value of lambdasub(f)=(6.85-0.20) x 10 -17 years -1 (Fleischer and Price 1964). (author) [es

  20. Thermal history of rocks in southern San Joaquin Valley, California: evidence from fission-track analysis

    Science.gov (United States)

    Naeser, N.D.; Naeser, C.W.; McCulloh, T.H.

    1990-01-01

    Fission-track analysis has been used to study the thermal and depositional history of the subsurface Tertiary sedimentary rocks on both sides of the active White Wolf reverse fault in the southern San Joaquin Valley. The distinctly different thermal histories of the rocks in the two structural blocks are clearly reflected in the apatite fission-track data, which suggest that rocks in the rapidly subsiding basin northwest of the fault have been near their present temperature for only about 1 m.y. compared with about 10 m.y. for rocks southeast of the fault. These estimates of heating time agree with previous estimates for these rocks. Zircon fission-track data indicate that the Tertiary sediments were derived from parent rocks of more than one age. However, from at least the Eocene to late Miocene or Pliocene, the major sediment source was rocks related to the youngest Sierra Nevada Mesozoic intrusive complexes, which are presently exposed east and south of the southern San Joaquin Valley. -from Authors

  1. Fission-track ages of Neogene and Quaternary volcanic ashes in south of Osaka, Japan

    International Nuclear Information System (INIS)

    Yokoyama, Takuo; Nakagawa, Yonosuke; Danhara, Tohru.

    1984-01-01

    A calculation method is proposed for the fission-track ages of zircon crystals in volcanic material. In this method, it is checked whether the spontaneous fission-track number of respective zircon crystals follows the Poisson distribution. If it does, the age is calculated by population method with all crystals, and if not, only with those crystals following the Poisson distribution, eliminating abnormal crystals. Extraneous zircon crystals are thus excluded and crystals with spontaneous fission-track number zero are not ignored. The following ages were obtained: Tamateyama volcanic ash in the Nijo group, 14.0 +- 0.6 Ma; pink volcanic ash in the Osaka group, 1.0 +- 0.2 Ma; Matsuo volcanic ash in the Ko-Osaka group, 1.5 +- 0.4 Ma; pumice volcanic ash in the Ko-Osaka group, 2.3 +- 0.4 Ma; Asashiro volcanic ash in the Ko-Osaka group, 2.9 +- 0.6 Ma. (Mori, K.)

  2. Development of the fission fragment track registration technique for the determination of the uranium contamination

    International Nuclear Information System (INIS)

    Tanaka, E.M.

    1979-01-01

    The Fission Fragment Track Registration Technique is developed to measure the uranium concentration about microgram of uranium per litre of liquid samples. The drying method of drops on the detector (Makrofol KG) and a special sampling procedure to avoid the cumbersome high density of tracks formation at the edge of the deposition surface as a 'ring' is adopted. The samples are irradiated by neutrons produced by the IEA-R1 Reactor (thermal neutron flux about 10 12 neutrons/cm 2 .s) inducing the uranium fission. The tracks registered by the fission fragments in the detector are chemically enlarged and counted by an automatic couting system. By this method the uranium concentrations ranging from 0,9 to 7,6 microgram of uranium per litre, can be determined with precisions between 2,7% the greater and 23% to the lower concentration. The uranium concentration measurements in human hair and urine are made showing that this method is very useful to control and detect eventual uranium contamination [pt

  3. Superheavy-element fission tracks in iron meteorites, and reply by Bull, R.K

    International Nuclear Information System (INIS)

    Runcorn, S.K.

    1980-01-01

    Comment is made on the lack of superheavy element (SHE) fission tracks observed in silicates from the class IA Odessa iron meteorite by Bull (Nature; 282:393 (1979)). Two explanations are suggested. Firstly, a thermal history for Odessa can be constructed in which the meteorite reaches track retention temperatures only after a time corresponding to many half lives for the SHEs (taken to be approximately 100 Myr) has elapsed and secondly that the IA irons never took up many SHEs. These suggestions are discussed in a reply by Bull. (U.K.)

  4. Extrapolation of zircon fission-track annealing models

    International Nuclear Information System (INIS)

    Palissari, R.; Guedes, S.; Curvo, E.A.C.; Moreira, P.A.F.P.; Tello, C.A.; Hadler, J.C.

    2013-01-01

    One of the purposes of this study is to give further constraints on the temperature range of the zircon partial annealing zone over a geological time scale using data from borehole zircon samples, which have experienced stable temperatures for ∼1 Ma. In this way, the extrapolation problem is explicitly addressed by fitting the zircon annealing models with geological timescale data. Several empirical model formulations have been proposed to perform these calibrations and have been compared in this work. The basic form proposed for annealing models is the Arrhenius-type model. There are other annealing models, that are based on the same general formulation. These empirical model equations have been preferred due to the great number of phenomena from track formation to chemical etching that are not well understood. However, there are two other models, which try to establish a direct correlation between their parameters and the related phenomena. To compare the response of the different annealing models, thermal indexes, such as closure temperature, total annealing temperature and the partial annealing zone, have been calculated and compared with field evidence. After comparing the different models, it was concluded that the fanning curvilinear models yield the best agreement between predicted index temperatures and field evidence. - Highlights: ► Geological data were used along with lab data for improving model extrapolation. ► Index temperatures were simulated for testing model extrapolation. ► Curvilinear Arrhenius models produced better geological temperature predictions

  5. Thermal annealing of fission tracks in fluorapatite, chlorapatite, manganoanapatite, and Durango apatite: experimental results

    International Nuclear Information System (INIS)

    Ravenhurst, C.E.; Roden-Tice, M.K.; Miller, D.S.

    2003-01-01

    It is well known that the optically measured lengths of fission tracks in apatite crystals are a function of etching conditions, crystallographic orientation of the track, composition of the crystal, and the state of thermal annealing. In this study we standardize etching conditions and optimize track length measurability by etching until etch pits formed at the surface of each apatite crystal reached widths of about 0.74 μm. Etching times using 5M HNO 3 at 21 o C were 31 s for Otter Lake, Quebec, fluorapatite; 47 s for Durango, Mexico, apatite; 33 s for Portland, Connecticut, manganoanapatite; and 11 s for Bamle, Norway, chlorapatite. An etching experiment using two etchant strengths (5M and 1.6M HNO 3 ) revealed that, despite significant differences in etch pit shape, fission-track length anisotropy with respect to crystallographic orientation of the tracks is not a chemical etching effect. A series of 227 constant-temperature annealing experiments were carried out on nuclear reactor induced tracks in oriented slices of the apatites. After etching, crystallographic orientations of tracks were measured along with their lengths. The 200-300 track lengths measured for each slice were ellipse-fitted to give the major (c crystallographic direction) and minor (a crystallographic direction) semi-axes used to calculate equivalent isotropic lengths. The equivalent isotropic length is more useful than mean length for thermal history analysis because the variation caused by anisotropy has been removed. Using normalized etching procedures and equivalent isotropic length data, we found that the fluorapatite anneals most readily, followed by Durango apatite, manganoanapatite, and lastly chlorapatite. (author)

  6. Studies on the Th biodistribution in internal contamination by the fission track method using animals

    International Nuclear Information System (INIS)

    Ciubotariu, M.; Danis, A.; Dumitrescu, G.; Cucu, M.

    1998-01-01

    In our previous studies on the U internal contamination, qualitative and quantitative results were obtained by using the fission track methods. In order to obtain complete data on the fissionable element internal contamination using animals, we started a similar study using Th as contaminating element and Wistar London breed rats as laboratory animals. Different ways to obtain internal contaminations were investigated: ingestion, inhalation, absorption by skin and through wounds. In this stage, Wistar-London breed rats of the same sex, weight and age were internal contaminated by 1 ml Th solution ingestion for each rat corresponding to an Annual Limit Intake.The animals were kept in normal life conditions and under permanent medical surveillance up to their sacrifice. Also, their evacuations where sampled every 24 hours. They were sacrificed at different time intervals after their contamination: 2 days (RAT 1), 7 days (RAT 2) and 14 days (RAT 3). After sacrifice, their vital organs were sampled, weighed, calcined, reweighed and finally analysed by track detection using the fission track micromapping technique. This technique was used in the following conditions: - mica-muscovite as track detector pre-etched for fossil tracks 18 h in HF; - the neutron irradiations were performed in the nuclear reactor VVR-S Bucharest at the neutron fluences of 3x10 15 - 2x10 16 fast neutrons/cm 2 . In order to check whether there is any U contribution to the fission track densities obtained in track detectors, U existing in the rat body due to food and water, the neutron irradiations of the ensembles were performed with and without 1 mm Cd shielding; - the visualization of the Th induced fission tracks were obtained by chemical etching in HF, 3 h at room temperature; - the Th track micromappings obtained in track detectors were studied by optical microscopy using a stereomicroscope WILD M7S for ensemble study (X6-X31) and a binocular ZEISS JENA microscope for qualitative and

  7. Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS).

    Science.gov (United States)

    Wu, Hang; Wu, Shixiang; Qiu, Nansheng; Chang, Jian; Bao, Rima; Zhang, Xin; Liu, Nian; Liu, Shuai

    2018-01-01

    Apatite fission-track (AFT) analysis, a widely used low-temperature thermochronology method, can provide details of the hydrocarbon generation history of source rocks for use in hydrocarbon exploration. The AFT method is based on the annealing behavior of fission tracks generated by 238 U fission in apatite particles during geological history. Due to the cumbersome experimental steps and high expense, it is imperative to find an efficient and inexpensive technique to determinate the annealing degree of AFT. In this study, on the basis of the ellipsoid configuration of tracks, the track volume fraction model (TVFM) is established and the fission-track volume index is proposed. Furthermore, terahertz time domain spectroscopy (THz-TDS) is used for the first time to identify the variation of the AFT annealing degree of Durango apatite particles heated at 20, 275, 300, 325, 450, and 500 ℃ for 10 h. The THz absorbance of the sample increases with the degree of annealing. In addition, the THz absorption index is exponentially related to annealing temperature and can be used to characterize the fission-track volume index. Terahertz time domain spectroscopy can be an ancillary technique for AFT thermochronological research. More work is urgently needed to extrapolate experimental data to geological conditions.

  8. Absolute measurement of thermal neutron fluence and its application for fission track dating

    International Nuclear Information System (INIS)

    Ganzawa, Yoshihiro; Honda, Teruyuki; Nozaki, Tetsuya.

    1988-01-01

    The absolute measurements of thermal neutron fluence for fission track dating have been developed after the proceeding results of Honda et al. (1987). The 2,200 m/sec activation cross section of 197 Au (98.8 barn) is corrected to 87.4 barn (σa) by the three factors of the neutron temperature, Maxwellian distribution of thermal neutrons and non 1/v correction factor for the above absolute measurement. The calibrated factor (B th ) of standard glasses (SRM613, SRM962a, CN-1 and CN-2) and zeta-a (ζa) values for fission track dating are determined on the basis of these experimental results. The values of B th , (7.47 ± 0.29) x 10 9 for SRM613, (7.43 ± 0.34) x 10 9 for SRM962a, (2.50 ± 0.06) x 10 9 for CN-1 and (2.74 ± 0.06) x 10 9 for CN-2 closely agree with those reported previously by Honda et al. (1987). Further, the ζa values of 392.3 ± 16.5 for SRM962a and SRM613, 131.4 ± 3.1 for CN-1 and 144.1 ± 3.3 for CN-2 calculated from B th , effective thermal neutron fission cross-section σf (497.4 barn), isotopic abundance ratio 235 U/ 239 U, I (7.2527 x 10 -3 ) and spontaneous fission decay constant of 238 U, λ f (6.85 x 10 -17 a -7 ) show close agreement with ζ b values (392.5 ± 10.0, 131.6 ± 3.3, 140.1 ± 3.5) derived from the absolute age of Fish Canyon Tuff (27.9 ± 0.7 Ma) respectively. The fission track dating of zircons separated from Oligocene-Miocene tuff distributed in Eastern Hokkaido have been carried out by the external detector method using ζ a . The obtained ages are 28.6 ± 0.7 Ma (1 - 2) and 23.3 ± 0.7 Ma (3 - 2). These results agree well with the geologic age supported from Ashoro Fossil Fauna, K-Ar ages of volcanic rocks and stratigraphy in this area. (author)

  9. Study on the technical feasibility of Fission-Track dating at two irradiation positions of the RA-6 research reactor

    International Nuclear Information System (INIS)

    Dorval, Eric

    2005-01-01

    The method of Fission-Track dating is based upon the detection of the damage caused by fission fragments from the Uranium contained in geological samples.In order to determine the age of a sample, both the amount of spontaneous fissions occurred and the Uranium concentration must be known.The latter requires the irradiation of the samples inside a reactor with a well-thermalized flux, so that fissions are induced over 235 U targets only. Therefore, the Uranium concentration may be determined.The main inconvenient presented by the irradiation sites at the RA-6 MTR-type reactor is that neutron flux is not completely thermal there, which means that fissions due to epithermal and fast neutrons will not be negligible.In the same way, tracks due to fissions of 238 U and 232 Th will be detected. In order to know the corrections that must be applied to those measurements performed in this reactor, it is necessary to characterize fast flux.Because of it, this laboratory's gamma spectrometry equipment had to be calibrated. After that, several activation detectors were irradiated and results were analyzed. Finally, it was determined that it is feasible to Fission-Track date at the I6 position. However, limitations associated to this method were analyzed for the values of flux measured in the different sites

  10. International Union of Geological Sciences Subcommission on Geochronology recommendation for the standardization of fission track dating calibration and data reporting

    International Nuclear Information System (INIS)

    Hurford, A.J.

    1990-01-01

    Because of the difficulties of calibration in fission track (FT) dating over the last 20 yr, including uncertainty of the absolute λ f value, complexities of neutron dosimetry, complexities of neutron irradiation, correction factors necessary in some methodological procedures, and personal factors in track counting, the Working Group elected at the Cambridge ICOG meeting in 1986 recommended to FT workers meeting at the 6th International Fission Track Dating Workshop in Besancon on 9 September 1988, a uniform approach to system calibration, sample irradiation, calculation of FT age, and presentation of data. After discussion and modification, the recommendation was accepted. This modified recommendation is presented. (author)

  11. Fission track dating of authigenic quartz in red weathering crusts of carbonate rocks in Guizhou province

    International Nuclear Information System (INIS)

    Liu Xiuming; Wang Shijie; Zhang Feng

    2004-01-01

    The Cenozoic evolution history of Guizhou Province, which is located on the southeastern flank of the Qinghai-Tibet Plateau, is unclear because of the lack of sedimentation records. The red weathering crusts widespread on the Yunnan-Guizhou Plateau may bear critical information about their evolution history. This work firstly determined the ages of four red weathering crusts in eastern, central and northern Guizhou. The material used in fission track dating is well-crystallized quartz occurring in many in-situ weathering crusts of carbonate rocks. The results showed that the fission track ages of quartz vary over a wide range from 1 Ma to 25 Ma in the four profiles, significantly younger than the ages of Triassic and Cambrian parent rocks. In combination with the regionally geological evolution history during the period from 25 Ma to 1 Ma, the ages of quartz can exclude the possibility that the origin of quartz has nothing to do with primary clastic minerals in parent rocks, authigenesis during diagenesis and hydrothermal precipitation or replacement by volcanic activities. It is deduced that the well-crystallized quartz was precipitated from Si-rich weathering fluids during weathering processes of carbonate rocks. The recorded ages of quartz from the four profiles are consistent with the episodes of planation surfaces on the Qinghai-Tibet Plateau, the stages of red soil in the tropics of South China, the tectonically stable periods in Guizhou, and the ages of weathering in other parts of the world during the Cenozoic era. That is to say, the ages of authigenic quartz dated by the fission track method are well feasible and credible. (authors)

  12. Denudation history of the Snowy Mountains: constraints from apatite fission track thermochronology

    International Nuclear Information System (INIS)

    Kohn, B.P.; Gleadow, A.J.W.; Cox, S.J.D.

    1999-01-01

    Apatite fission track thermo chronology from Early Palaeozoic granitoids centred around the Kosciuszko massif of the Snowy Mountains, records a denudation history that was episodic and highly variable. The form of the apatite fission track age profile assembled from vertical sections and hydro-electric tunnels traversing the mountains, together with numerical forward modelling, provide strong evidence for two episodes of accelerated denudation, commencing in Late Permian - Early Triassic (ca 270 250 Ma) and mid-Cretaceous (ca 110-100 Ma) times, and a possible third episode in the Cenozoic. Denudation commencing in the Late Permian - Early Triassic wins widespread in the eastern and Central Snowy Mountains area, continued through much of the Triassic, and amounted to at least ∼2.0-2,4 km. This episode was probably the geomorphic response to the Hunter-Bowen Orogeny. Post-Triassic denudation to the present in these areas amounted to ∼2.0-2.2 km. Unambiguous evidence for mid-Cretaceous cooling and possible later cooling is confined to a north-south-trending sinuous belt, up to ∼15km wide by at least 35km long, of major reactivated Palaeozoic faults on the western side of the mountains. This zone is the most deeply exposed area of the Kosciuszko block. Denudation accompanying these later events totalled up to ∼1.8-2.0 km and ∼2.0 2.25 km respectively. Mid-Cretaceous denudation marks the onset of renewed tectonic activity in the south-eastern highlands following a period of relative quiescence since the Late Triassic, and establishes a temporal link with the onset of extension related to the opening of the Tasman Sea. Much of the present day relief of the mountains resulted from surface uplift which disrupted the post-mid-Cretaceous apatite fission track profile by variable offsets on faults. Copyright (1999) Geological Society of Australia

  13. Solid state nuclear track detectors in the measurement of alpha to fission branching ratios of heavy actinides

    International Nuclear Information System (INIS)

    Pandey, A.K.; Sharma, R.C.; Padalkar, S.K.; Kalsi, P.C.; Iyer, R.H.

    1992-01-01

    A sequential etching procedure for revelation of alpha and fission tracks in CR-39 was developed and optimized. Using this technique alpha and fission tracks can be differentiated unambiguously because of significant differences in their sizes and etching times. This registration and revelation procedure for alpha and fission tracks may be used for the studies of half lives, alpha to fission branching ratios and identification of radionuclides based on their decay schemes. It has the added advantage that both alpha decay and fission events can be studied using one detector and hence uncertainties related to efficiency, registration geometry, registration times, amount of radionuclides etc can be eliminated or minimized. The effects of neutron, gamma and alpha radiations on the alpha and fission fragment tracks registration and revelation properties of CR-39 detectors [CR-39, CR-39 (DOP)] were also studied. The IR spectra were also studied to find out the nature of chemical changes produced by these radiations on CR-39. (author). 32 refs., 7 figs., 4 tabs

  14. Determination of trace uranium in atmospheric precipitation of the Xiangjiang river valley by fission track method

    International Nuclear Information System (INIS)

    Zhai Pengji; Kang Tiesheng

    1986-01-01

    In this work the uranium contents in atmospheric precipitations in the region of the Xiangjiang River valley have been measured by fission track method, which range from 0.008 to 1.5 ppb. The majority of them are below 0.1 ppb. The uranium contents in the samples form different geographical positions are obviously different. Sometimes the differences in uranium contents of the samples from the same area collected at different times are also great. A preliminary discussion is given on the sources of uranium in atmospheric precipitation and on the reason of the difference in contents

  15. Experimental study of a methodology for Fission-track Dating without neutron irradiation

    International Nuclear Information System (INIS)

    Hadler, J.C.; Iunes, P.J.; Tello, C.A.; Chemale, F.; Kawashita, K.; Curvo, E.A.C.; Santos, F.G.S.; Gasparini, T.E.; Moreira, P.A.F.P.; Guedes, S.

    2009-01-01

    To carry out the dating by the Fission Track Method (FTM) the international community that works with this method employs methodologies in which the mineral to be dated must be irradiated with neutrons. Such irradiation, performed in a nuclear reactor, demand a relatively long waiting time so that the activity of the sample attain a proper level for handling. The present work aims to establish a methodology that makes possible the dating by FTM using a mass spectrometer instead of a nuclear reactor. This methodology was applied to apatite samples from Durango, Mexico.

  16. Emplacement time of Salai Patai carbonatite, Malakand, Pakistan, from fission track dating of zircon and apatite

    International Nuclear Information System (INIS)

    Qureshi, A.A.; Khan, H.A.

    1991-01-01

    Based on fission track dating of zircon and apatite, the emplacement history of Salai Patai carbonatite has been traced. It has been estimated that the carbonatite was emplaced along the thrust plane associated with the Indian-Eurasian plate collision during the Oligocene period followed by some thermal/tectonic episode during Early Miocene. This negates the previous proposal that all carbonatites found in Pakistan are a part of a 200 km long alkaline province associated with the rifting of Peshawar Valley during Late Cretaceous or early tertiary. (author)

  17. Application of fission track technique for estimation of uranium concentration in drinking waters of Punjab

    International Nuclear Information System (INIS)

    Prabhu, S.P.; Sawant, P.D.; Raj, S.S.; Kumar, A.; Sarkar, P.K.; Tripathi, R.M.

    2012-01-01

    Drinking water samples were collected from four different districts, namely Bhatinda, Mansa, Faridkot and Firozpur, of Punjab for ascertaining the U(nat.) concentrations. All samples were preserved, processed and analyzed by laser fluorimetry (LF). To ensure accuracy of the data obtained by LF, few samples (10 nos) from each district were analyzed by alpha spectrometry as well as by fission track analysis (FTA) technique. For FTA technique few μl of water sample was transferred to polythene tube, lexan detector was immersed in it and the other end of the tube was also heat-sealed. Two samples and one uranium standard were irradiated in DHRUVA reactor. Irradiated detectors were chemically etched and tracks counted using an optical microscope. Uranium concentrations in samples ranged from 3.2 to 60.5 ppb and were comparable with those observed by LF. (author)

  18. New approaches in fission track geochronology as a tectonic tool: examples from the Transantarctic Mountains

    International Nuclear Information System (INIS)

    Fitzgerald, P.G.

    1990-01-01

    Apatite fission track analysis has been applied to study the uplift history and tectonics of the Transantarctic Mountains. An uplifted fossil apatite annealing zone has been identified in the apatite age vs elevation profile and is confirmed by track length data. A ''break in slope'' in the apatite age profile marks the base of the uplifted partial annealing zone and approximates the time of initiation of uplift of the mountains. Samples below the ''break in slope'' give information on the rate(s) of uplift. Samples above the break have apatite ages that vary significantly with elevation, but the gradient is not equal to an apparent uplift rate. Rather, it is due to inherited characteristics from the pre-existing partial annealing zone. These samples above the ''break in slope'' can be used as indicators of paleo-depth in the pre-uplift crust to determine the structure of an area and the displacement across faults. (author)

  19. Concentration of uranium in human cancerous tissues of Southern Iraqi patients using fission track analysis

    International Nuclear Information System (INIS)

    Al-Hamzawi, A.A.; Al-Qadisiyah University, Qadisiyah; Jaafar, M.S.; Tawfiq, N.F.

    2015-01-01

    The technique of nuclear fission track analysis with solid state nuclear track detectors CR-39 has been applied to determine concentrations of uranium in cancerous samples of human tissues that excised from patients in the three key southern Iraqi governorates namely, Basrah, Dhi-Qar, and Muthanna. These provinces were the sites of intensive military events during the Gulf Wars in 1991 and 2003. The investigation was based on the study of 24 abnormal samples and 12 normal samples for comparing the results. These samples include four types of soft tissues (kidney, breast, stomach and uterus). The results show that uranium concentrations in the normal tissues ranged between (1.42-4.76 μg kg -1 ), whereas in the cancerous tissues ranged between (3.37-7.22 μg kg -1 ). The uranium concentrations in the normal tissues were significantly lower than in the abnormal tissues (P < 0.001). (author)

  20. Determination of the uranium content in phosphate fertilizers by the fission track registration technique

    International Nuclear Information System (INIS)

    Rocha, A.C.S. da.

    1983-01-01

    The application of fission track registration technique (SSNTD) to determine the uranium contents in phosphate fertilizers is dealt with. Samples were prepared by the wet method and the detector used was Makrofol Kg 10μm thick. The determination of uranium in phosphate fertilizer industry is of considerable interest in environmental control. The roots of vegetables tend to absorb and accumulate uranium form soil and so the human body could be contaminated. The phosphate fertilizers were originated from the phosphate-rich apatite deposits located in the high naturally radioactive areas of Araxa and Tapira in the state of Minas Gerais, Brazil. The results obtained ranged from 11.1 to 100ppm of uranium with a total error from 8.2 to 15.7%. The thorium contributions to the total track counting were discounted, though the actual concentrations of thorium in the samples were not determined. (Author) [pt

  1. The Comparison Study of Neutron Activation Analysis and Fission Track Technique for Uranium Determination

    International Nuclear Information System (INIS)

    Sirinuntavid, Alice; Rodthongkom, Chouvana

    2007-08-01

    Full text: Comparison between Neutron Activation Analysis (NAA) and fission track technique for uranium determination in solid samples was studied by use of standard reference materials, i.e., ore, coal fly ash, soil. For NAA, the epithermal neutron was applied for activated irradiation. Then, the 74.5 keV gamma from U-239 or 277.7 keV gamma from Np-239 was measured. For high Uranium content samples, NAA method with 74.5 keV gamma measurement, gave higher precision result than the 277.7 keV gamma measurement method. NAA method with 277.7 keV gamma measurement, gave higher sensitivity and precision result for low Uranium content samples and the uranium contained less than 10 ppm samples. Nevertheless, the latter procedure needed longer time for neutron irradiation and analysis procedure. In comparison the results of Uranium analysis between NAA and fission track, it was found that no significant difference within 95 % of confidence level

  2. Determination of the uranium concentration in water samples by the technique of fission track recording

    International Nuclear Information System (INIS)

    Geraldo, L.P.

    1979-01-01

    The technique of fission track register was developed for the determination of micrograms of uranium. The Makrofol KG, a synthetic plastic made by Bayer, was used as the detector and the wet method was utilized. The detector calibration curve allows the determination of the uranium concentration in a sample within an interval from 8.0 to 0.4μgU/L, the total error ranging from 3.3% to 29.0% respectively. The method was used in the determination of the uranium content in various water samples, obtained from various sources like rivers, sea etc. in the state of Sao Paulo, Brazil. Results were compared with those obtained by other authors using different methods. The average concentration found in sea waters (3.27 +- 9.12μgU/l) by this method is compatible with the international average accepted value of 3.3μgU/l, irrespective of site and depth. The determination of the uranium content by fission track counting has proved to be very convenient. (Author) [pt

  3. Fission track dating of tuffaceous eocene formations of the North Bakony Mountains (Transdanubia, Hungary)

    International Nuclear Information System (INIS)

    Dunkl, I.

    1990-01-01

    Fission track dating was performed in accessory minerals of strongly altered, clay mineralized tuffite strata lying in the upper part of the Eocene sequence of the North Bakony Mountains. The homogeneity of the fission track (FT) ages measured on apatite and zircon refers only to insignificant redeposition, no remarkable mingling of the detrital matter vould be stated. The average of the FT-ages falls to the Bartonian, into the time interval determined by nannoplankton guide horizons for the volcanic activity (41.9 ± 4.1 Ma). As to their biostratigraphic age the Middle Eocene samples show an FT-average of 44.2 ± 3.4 Ma, the average of the Upper Eocene group is 39.9 ± 4.1 Ma. The difference between the two groups refers to the two phases of the volcanic activity. The first maximum of volcanism generated the Upper Lutetian to Bartonian glauconitic sequence while the second maximum at the Bartonian-Priabonian boundary produced the tuff strata. The strata in the neighbouring areas relate to continuous volcanism in the Upper Eocene, in the studied area, however, the upper part of the Priabonian was eroded. (author) 51 refs.; 4 figs.; 1 tab

  4. The obsidian from Quiron (Salta Province, Argentina): a new reference glass for fission-track dating

    Energy Technology Data Exchange (ETDEWEB)

    Bigazzi, G. [Istituto di Geoscienze e Georisorse, C.N.R., Area della Ricerca di Pisa, V.G. Moruzzi, 1, 56124 Pisa (Italy)]. E-mail: g.bigazzi@igg.cnr.it; Laurenzi, M.A. [Istituto di Geoscienze e Georisorse, C.N.R., Area della Ricerca di Pisa, V.G. Moruzzi, 1, 56124 Pisa (Italy); Viramonte, J.G. [Instituto Geonorte, Universidad Nacional de Salta and Conicet, Buenos Aires 177, 4400 Salta (Argentina)

    2005-12-01

    In the course of a geochronological study of the volcanic activity in the Andean Cordillera in northern Argentina, we have found in the El Quevar volcanic complex (24 deg. 19{sup '}S/66 deg. 43{sup '}W,6180m) a phenocryst poor obsidian (Quiron obsidian) showing an unusually high spontaneous track density. Defects which might produce 'spurious' tracks are virtually absent. Application of fission-track dating using an absolute approach, based on the IRMM-540 standard glass for neutron fluence measurements, yielded an apparent age of 7.27+/-0.29Ma(1{sigma}) and a plateau age of 8.99+/-0.31Ma(1{sigma}). A {sup 40}Ar-{sup 39}Ar isochron age on biotite of 8.61+/-0.04Ma(1{sigma}) was already available for the Quiron rhyolite. We determined further {sup 40}Ar-{sup 39}Ar ages on several chips of the glass itself using two analytical approaches: total fusion with a focussed laser beam (LTFA) and a step-heating approach using a de-focussed laser beam (LSHA). We have obtained a weighted average of 8.77+/-0.09Ma, an isochron age of 8.71+/-0.12Ma and an integrated age of 8.77+/-0.09Ma for LTF analyses, and a w.a. of 8.75+/-0.09Ma, an iso.a. of 8.77+/-0.09Ma and an int.a. of 8.77+/-0.09Ma for LSH analyses (all age errors are 2{sigma}). The Quiron obsidian is very easy to analyse for its high spontaneous track density and because microlites which might produce spurious tracks are very rare. Independent reference {sup 40}Ar-{sup 39}Ar ages determined in different laboratories are available. For these reasons we believe that this glass may be very useful for testing fission-track system calibrations and apparent age correction procedures. Splits of obsidian Quiron will be distributed upon request to colleagues who intend to test it.

  5. The effects of radiation damage accumulation and annealing on fission-track dating of titanite

    International Nuclear Information System (INIS)

    Enkelmann, Eva; Jonckheere, Raymond; Ratschbacher, Lothar

    2005-01-01

    Fission-track dating of titanite is hindered by the fact that track etching is anisotropic in fresh titanites and becomes isotropic with increasing radiation damage. Independent age determinations with the population method are problematic due to different track counting efficiencies (Q) for ρ s in unannealed and ρ i in annealed titanite. Independent age determinations with the external detector method depend on correction factors for the track registration geometries (G = 0.5), counting efficiencies (Q) and range deficit (R = 1.38); however, Q is unaffected by annealing. It was attempted to determine GQR through calculation, direct experiment and on the basis of age standards. The direct experiment involves measurements of the ratio of the induced-track densities in titanite and a co-irradiated external detector. The track densities in the internal titanite surfaces could not be measured but the results for the external surfaces confirm that this approach leads to a significant overestimation of GQR, due to prior annealing. The GQR-values determined on the basis of age standards are consistent with that obtained by calculation assuming that Q ∼ 1, although there is no experimental confirmation for this fact apart from their isotropic etching characteristics. The fact that identical GQR-factors were obtained on standards of different age and uranium content suggests that a single GQR-value is appropriate for dating titanites within a broad range of radiation damage. In terms of the ζ-calibration this implies that a single ζ-factor is also suitable for dating different titanites. These findings suggest that other factors besides the accumulation of alpha-recoil damage, such as a phase transition, could be co-responsible for the different etching characteristics of annealed and unannealed titanites

  6. Fission track dating evidence on tectonic activities of northern Himalaya block

    International Nuclear Information System (INIS)

    Yuan Wanming; Wang Shicheng; Wang Lanfen

    2002-01-01

    Fission track ages (FTA) of 4 apatite samples collected from Langkazi to Yarlung Zangbo thrust zone range between 13.6 and 17.2 Ma, reflecting the time of continent-continent collision and differing from previous data. The negative correlation between the FTA and sample elevations shows there was rapid uplifting during the continent-continent collision with uplifting rate of 176 m/Ma. Denudation degree, denudation rate and cooling rate were ∼2.9 km, 213 m/Ma and 7 degree C/Ma respectively since 13.6 Ma. FTA of 3 zircon samples are different significantly and have x 2 test value of < 0.1%, confirming the orogeny within continent went under low temperature

  7. Improving process methodology for measuring plutonium burden in human urine using fission track analysis

    International Nuclear Information System (INIS)

    Krahenbuhl, M.P.; Slaughter, D.M.

    1998-01-01

    The aim of this paper is to clearly define the chemical and nuclear principles governing Fission Track Analysis (FTA) to determine environmental levels of 239 Pu in urine. The paper also addresses deficiencies in FTA methodology and introduces improvements to make FTA a more reliable research tool. Our refined methodology, described herein, includes a chemically-induced precipitation phase, followed by anion exchange chromatography and employs a chemical tracer, 236 Pu. We have been able to establish an inverse correlation between Pu recovery and sample volume and our data confirms that increases in sample volume do not result in higher accuracy or lower detection limits. We conclude that in subsequent studies, samples should be limited to approximately two liters. The Pu detection limit for a sample of this volume is 2.8 μBq/l. (author)

  8. Fission-track dating of pumice from the KBS Tuff, East Rudolf, Kenya

    Science.gov (United States)

    Hurford, A.J.; Gleadow, A.J.W.; Naeser, C.W.

    1976-01-01

    Fission-track dating of zircon separated from two pumice samples from the KBS Tuff in the Koobi Fora Formation, in Area 131, East Rudolf, Kenya, gives an age of 2.44??0.08 Myr for the eruption of the pumice. This result is compatible with the previously published K-Ar and 40Ar/ 39Ar age spectrum estimate of 2.61??0.26 Myr for the KBS Tuff in Area 105, but differs from the more recently published K-Ar date of 1.82??0.04 Myr for the KBS Tuff in Area 131. This study does not support the suggestion that pumice cobbles of different ages occur in the KBS Tuff. ?? 1976 Nature Publishing Group.

  9. Determination of the uranium concentration in apatite by the fission - track registration technique

    International Nuclear Information System (INIS)

    D'Oliveira Cardoso, D.

    1983-01-01

    The feasibility of using the fission-track registration technique to determine the uranium content in the phosphate rock beneficiation steps carried on by CompanhiA Arafertil, Araxa, Minas Gerais, Brazil is studied. This determination is of considerable interest to the environmental control of the Arafertil installations as well as of its surroundings or of the areas where these products will be used. The so called wet method was adopted and a 10 μm polycarbonate foil, fabricated by Bayer under the trade name Makrofol KG was used as detector. From the calibration curve obtained, it was possible to determine uranium contents in sample solutions ranging from 21 to 212 μg U/1 with an accuracy of 8 to 14.7%, respectively. The results obtained demonstrated that the technique used is appropriate to the purposes previously aimed at. (Author) [pt

  10. Fission track dating of mesozoic sandstones and its tectonic significance in the Eastern Sichuan Basin, China

    International Nuclear Information System (INIS)

    Shen Chuanbo; Mei Lianfu; Xu Sihuang

    2009-01-01

    To establish the tectonic evolution of the eastern Sichuan basin, apatite fission track dating and time-temperature thermal history modeling were carried to analyze on 11 samples collected from Jurassic sandstones. The results indicate that the cooling and exhumation process of the eastern Sichuan basin can be divided into three stages since Cretaceous, (1) a rapid cooling phase between ∼100 and ∼70 Ma, (2) following by a period of relative thermal stability phase between ∼70 and ∼15 Ma, (3) and then a new rapid cooling stage after ∼15 Ma. Two rapid cooling events imply that the eastern Sichuan basin once underwent two tectonic movements since Cretaceous. The first rapid cooling is associated with Mesozoic tectonic reactivation beginning at 100 Ma, which result in folds and faults of the eastern Sichuan basin. The second tectonic movement occurred at 15 Ma, which is related to denudation by compression resulting from the eastward growth of Tibetan plateau uplift.

  11. Application of fission track method in the development study of coalbed methane

    International Nuclear Information System (INIS)

    Li Xiaoming; Peng Gelin

    2002-01-01

    In order to explore potential resource of coalbed methane in Xinji coal deposit of Huainan coalfield, its tectonic-thermal evolution history was studied by using fission track technique. The results showed that there had been 3 or more times of significant thermal events occurred in this area since the late Paleozoic Era. The paleo-geothermal gradient was higher than that of the present. It was estimated that the denudation thickness in this area should be over 2000 m. Mainly formed between 240-140 Ma, no abundant methane could be generated in such condition. Furthermore, the tectonic-thermal events would release the most of methane gases. So, the potential resource of the coalbed methane in this are might be limited

  12. An international research project on Armenian archaeological sites: fission-track dating of obsidians

    Energy Technology Data Exchange (ETDEWEB)

    Badalian, R.; Bigazzi, G. E-mail: g.bigazzi@iggi.pi.cnr.it; Cauvin, M.-C.; Chataigner, C.; Jrbashyan, R.; Karapetyan, S.G.; Oddone, M.; Poidevin, J.-L

    2001-06-01

    In the Mediterranean and adjacent regions, the Caucasus is one of the less studied areas in relation to provenance studies of prehistoric obsidian artefacts. In the frame of an international INTAS research project, an extensive surveying and sampling campaign was carried out in the numerous obsidian bearing volcanic complexes of Armenia. 33 obsidian samples were analysed using the fission-track dating method in order to characterise the potential sources of the numerous artefacts found in prehistoric sites. Ages cluster into five groups--Upper Neopleistocene Q{sub III}, Middle Neopleistocene Q{sub II}, Lower Neopleistocene Q{sub I}, Lower Eopleistocene Q{sub EI} and Lower Pliocene N{sub 3}{sup 1} groups. This research represents a significant contribution to a better knowledge of chronology of Armenian volcanism for which only few data were available. The resulting data-set appears to be a solid base for future provenance studies.

  13. Trace uranium determination in beverages and mineral water using fission track techniques

    International Nuclear Information System (INIS)

    Cheng, Y.L.; Lin, J.Y.; Hao, X.H.

    1993-01-01

    The uranium contents of beverages and mineral water have been estimated using the technique of fission track analysis with polycarbonate detector. The U contents in beverages have been found to vary from 0.26 ± 0.03 to 1.65 ± 0.07 ppb, the average value is 0.93 ± 0.05 ppb. The mean U content in mineral water is 9.20 ± 0.16 ppb, which is ∼ 10 times higher than the mean U content of beverages. The present study shows the high U content in mineral water, indicating need for further investigation of U content in mineral water for the studies of radiation health hazards. (Author)

  14. On the use of thin natural uranium film dosimetry in mineral dating by the fission track method

    International Nuclear Information System (INIS)

    Hadler Neto, J.C.; Iunes, P.J.; Khouri, M.C.

    1993-01-01

    Three obsidian samples were irradiated in a neutron facility and their age was measured by the fission track method; using a thin uranium film dosemeter. The results were compared to others made previously on the same type of rock using conventional neutron dosimetry. The use of thin uranium film for age determination is discussed. (F.E.). 20 refs, 4 tabs

  15. Detection alpha particles and Cf-252 fission fragments with track solid detectors and with surface barrier detectors: efficiency determination

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.R.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    The technique of particle detection by solid track detectors, types of developing and analysis of results are presented. Efficiency measurements of alpha particle detection with Makrofol e and surface barrier detector are made. Detection of Cf-252 fission fragments is shown. (L.C.)

  16. Application of fission track and other new technics in the study of geothermal history for Liaohe Basin

    International Nuclear Information System (INIS)

    Xia Yuliang; Zhu Jiechen; Zheng Maogong; Zhao Yunlong; Hu Zhenduo; Guo Xiuying; Gao Shangkui

    1994-11-01

    Mainly based on the study of fission track of the apatites, as well as geochronology, stable isotope composition and inclusion analysis, the principle and method of studying the geothermal history of sedimentary basin have been expounded systematically, and the source of sediment materials, and the geothermal characteristics of five section areas in Liaohe Basin were determined. The results of apatites and zircons U-Pb dating indicate that the materials of Shahejie Group in Liaohe Basin derived from the Shanhaiguan old land, and the record time of fission track of the apatites started at 172 Ma ago. On the basis of the studies of fission track characters of 100 apatite samples, stable isotopes and inclusion analysis, the annealing zone of fission track, oil generation zone and the old geothermal gradient were determined respectively in the western slope, southern part of western depression, Niuju area, Huangjindai area of eastern depression and Shallow sea area. It has provided the important scientific basis of reevaluating oil resources in Liaohe Basin. (2 tabs.)

  17. Detection of alpha particles and Cf-252 fission fragments with solid track detectors and surface barrier detector. Efficiency calculation

    International Nuclear Information System (INIS)

    Khouri, M.T.F.C.; Koskinas, M.F.; Andrade, C. de; Vilela, E.C.; Hinostroza, H.; Kaschiny, J.E.A.; Costa, M.S. da; Rizzo, P.; Santos, W.M.S.

    1990-01-01

    A technique for particle detection by using track solid detector and also types of revealing and result analysis are presented concerned to Cf-252 fission fragments detection. Measurements of alpha particles detection efficiency using Makrofol E and surface barrier detector are performed. (L.C.J.A.)

  18. On the fission track dating and annealing behaviour of accessory minerals of Eastern Ghats (Andhra Pradesh, India)

    International Nuclear Information System (INIS)

    Koul, S.L.

    1978-01-01

    Use of the etching of fission fragment damage tracks for an estimation of the uranium content of apatite and zircon crystals is described. The etching conditions have been studied for which visible tracks are developed. Fission track determined ages of 25 samples of apatite and zircon crystals from four widely separated regions of India; the Borra mines (Vishakapatanam), Kashipatnam (Vishakapatnam), the Khamam area (Andhra Pradesh) and the Kodrama mines (Bihar) have been determined. Mean ages for these regions are 456 +- 5, 389 +- 4, 486 +- 7 and 664 +- 7 million years respectively. It is concluded that the fission track ages of the minerals date the last metamorphic event of the Eastern Ghats, known as the Indian Ocean Cycle. Annealing studies confirm that radiation damaged fossil tracks can be erased in minerals under intense metamorphic episodes, thus resetting the geological clock. Extrapolation of the experimentally determined temperatures for annealing suggest that a temperature of 170 0 C in 10 6 years will erase all the tracks in the apatite mineral. The uranium concentration has been estimated to be approximately 10 -8 gm/gm in apatite and approximately 10 -6 gm/gm in zircon. (Auth.)

  19. Fission track dating of volcanic glass: experimental evidence for the validity of the Size-Correction Method

    International Nuclear Information System (INIS)

    Bernardes, C.; Hadler Neto, J.C.; Lattes, C.M.G.; Araya, A.M.O.; Bigazzi, G.; Cesar, M.F.

    1986-01-01

    Two techniques may be employed for correcting thermally lowered fission track ages on glass material: the so called 'size-correcting method' and 'Plateau method'. Several results from fission track dating on obsidian were analysed in order to compare the model rising size-correction method with experimental evidences. The results from this work can be summarized as follows: 1) The assumption that mean size of spontaneous and induced etched tracks are equal on samples unaffected by partial fading is supported by experimental results. If reactor effects such as an enhancing of the etching rate in the irradiated fraction due to the radiation damage and/or to the fact that induced fission releases a quantity of energy slightly greater than spontaneous one exist, their influence on size-correction method is very small. 2) The above two correction techniques produce concordant results. 3) Several samples from the same obsidian, affected by 'instantaneous' as well as 'continuous' natural fading to different degrees were analysed: the curve showing decreasing of spontaneous track mean-size vs. fraction of spontaneous tracks lost by fading is in close agreement with the correction curve constructed for the same obsidian by imparting artificial thermal treatements on induced tracks. By the above points one can conclude that the assumptions on which size-correction method is based are well supported, at least in first approximation. (Author) [pt

  20. Apatite fission track analysis: geological thermal history analysis based on a three-dimensional random process of linear radiation damage

    International Nuclear Information System (INIS)

    Galbraith, R.F.; Laslett, G.M.; Green, P.F.; Duddy, I.R.

    1990-01-01

    Spontaneous fission of uranium atoms over geological time creates a random process of linearly shaped features (fission tracks) inside an apatite crystal. The theoretical distributions associated with this process are governed by the elapsed time and temperature history, but other factors are also reflected in empirical measurements as consequences of sampling by plane section and chemical etching. These include geometrical biases leading to over-representation of long tracks, the shape and orientation of host features when sampling totally confined tracks, and 'gaps' in heavily annealed tracks. We study the estimation of geological parameters in the presence of these factors using measurements on both confined tracks and projected semi-tracks. Of particular interest is a history of sedimentation, uplift and erosion giving rise to a two-component mixture of tracks in which the parameters reflect the current temperature, the maximum temperature and the timing of uplift. A full likelihood analysis based on all measured densities, lengths and orientations is feasible, but because some geometrical biases and measurement limitations are only partly understood it seems preferable to use conditional likelihoods given numbers and orientations of confined tracks. (author)

  1. Trace uranium analysis in Indian coal samples using the fission track technique

    International Nuclear Information System (INIS)

    Jojo, P.J.; Rawat, A.; Kumar, Ashavani; Prasad, Rajendra

    1993-01-01

    The ever-growing demand for energy has resulted in the extensive use of fossil fuels, especially coal, for power generation. Coal and its by-products often contain significant amounts of radionuclides, including uranium, which is the ultimate source of the radioactive gas Radon-222. The present study gives the concentration of uranium in coal samples of different collieries in India, collected from various thermal power plants in the state of Uttar Pradesh. The estimates were made using the fission track technique. Latent damage tracks were not found to be uniformly distributed but showed sun bursts and clusters. Non-uniform distributions of trace elements are a very common phenomenon in rocks. The levels of uranium in the coal samples were found to vary from 2.0 to 4.9 ppm in uniform distributions and from 21.3 to 41.0 ppm in non-uniform distributions. Measurements were also made on fly ash samples where the average uranium concentration was found to be 8.4 and 49.3 ppm in uniform and non-uniform distributions, respectively. (author)

  2. Apatite fission track dating of the Northern Western Shield, Western Australia

    International Nuclear Information System (INIS)

    Weber, U.D.; Kohn, B.P.; Gleadow, A.J.W.

    1999-01-01

    Full text:The investigation of the thermotectonic evolution of the northern part of the Precambrian Western Shield of Western Australia using apatite fission track (AFT) thermochronology is the main focus of this study. The study area encompasses Precambrian rocks of the Pilbara Craton and the northern part of the Yilgarn Craton including the Narryer Gneiss Complex. AFT data, mostly from the Archaean cratons reveal cooling ages ranging between 260±8 Ma and 400±20 Ma. Mean confined horizontal track lengths fall between ∼12 and 13 μm with standard deviations ranging from 1.1-2.2 μm. Forward modelling of time-temperature history paths for representative samples reveals a period of regional cooling of at least ∼50 deg C in the late Palaeozoic. Most paths also show a second period of cooling of 25 deg C from temperatures of ∼80-85 deg C. This later cooling episode occurred in the Mesozoic but its timing is less well constrained. Assuming that the average present day geothermal gradient of ∼18±2 deg C per km - 1 was prevalent since the late Palaeozoic, then the minimum of ∼75 deg C of cooling predicted by the fission track modelling suggests overall denudation of at least ∼ 3.7-4.6 km of section since that time. Phanerozoic basins (Perth, Carnarvon and Canning) adjacent to the north and west of the northern Western Shield mostly continue offshore and form complex structures containing up to ∼ 15 km of predominantly clastic sediments of early Ordovician to late Cretaceous age. The basins are likely to have been depocentres for much of the detritus derived from the denudation inferred from the cooling recorded by the AFT. Possible causative events which could be linked to the observed late Palaeozoic cooling are tectonism related to the collision of Gondwanaland with Laurussia in Carboniferous time forming the supercontinent Pangea or a possible far-field effect related to the Alice Springs Orogeny. Further low temperature thermochronological studies

  3. Convection methodology for fission track annealing: direct and inverse numerical simulations in the multi-exponential case

    International Nuclear Information System (INIS)

    Miellou, J.C.; Igli, H.; Grivet, M.; Rebetez, M.; Chambaudet, A.

    1994-01-01

    In minerals, the uranium fission tracks are sensitive to temperature and time. The consequence is that the etchable lengths are reduced. To simulate the phenomenon, at the last International Conference on Nuclear Tracks in solids at Beijing in 1992, we proposed a convection model for fission track annealing based on a reaction situation associated with only one activation energy. Moreover a simple inverse method based on the resolution of an ordinary differential equation was described, making it possible to retrace the thermal history in this mono-exponential situation. The aim of this paper is to consider a more involved class of models including multi-exponentials associated with several activation energies. We shall describe in this framework the modelling of the direct phenomenon and the resolution of the inverse problem. Results of numerical simulations and comparison with the mono-exponential case will be presented. 5 refs. (author)

  4. Understanding the uplift pattern in Mesozoic and Cenozoic,, eastern Dabie area, China using fission track dating of apatite

    International Nuclear Information System (INIS)

    Wu Qianhong; Liu Shunsheng

    2002-01-01

    By using the fission track dating technique, a preliminary study was carried out on the fission track ages (FTA) of apatite, their distribution patterns and hints over the tectonics activities during Mesozoic and Cenozoic in the east Dabie area. Attempts were also made to improve the conventional statistical method for the tracks. Ranging from 59.4 +- 3.4 Ma to 105.6 +- 9.8 Ma, the FTA results of apatite spread in the wide range and increased rapidly from the east to the west area. Sine 95 Ma, the uplift rate has been quite slow and asymmetry. The FTA value in the middle area of Xiaotian-Mozitan Fault may imply its uplift in Cretaceous. The faulting should be the main control factor for the uplift of this area

  5. Enlarging the fission fragment tracks in glass detectors by etching in weak solutions of HF - a safe etchant

    International Nuclear Information System (INIS)

    Singh, V.P.; Sharma, A.P.

    1982-01-01

    The effect of etchant concentration and temperature on track revelation properties of soda glass detectors has been studied. Etch rate ratio, maximum observable diameter and the energy resolution of the fission fragment tracks of 252 Cf in glasses are increased when the samples are etched in 1.25 vol% HF as compared to higher concentrations of HF and other etching solutions. The critical angle of etching is found to decrease with decrease in etchant concentration. The activation energies for bulk etching and track etching have also been estimated. Better results were obtained by using lower etching temperatures. (author)

  6. The etching property of the surface of CR-39 and the track core radius of fission fragment

    CERN Document Server

    Mineyama, D; Yamauchi, T; Oda, K; El-Rahman, A

    2002-01-01

    The etch pits of fission fragments in CR-39 detector have been observed carefully using an atomic force microscope (AFM) after extremely short chemical etching in stirred 6N KOH solution kept at 70degC. It was found that there existed a thin layer where the bulk etch rate is relativity from large the etch-pit growth curve for the etching duration between 10 and 1800 seconds. The track core radius of fission fragment was evaluated to be about 6 nm from the extrapolation of the growth curve in a thinner region. (author)

  7. Fission track analysis of Pu in small specimens of biological material: Technical progress report, August 1, 1987--July 31, 1988

    International Nuclear Information System (INIS)

    Wrenn, M.E.

    1988-01-01

    The objective of this research is to develop a highly specific and ultrasensitive method capable of detecting 100 aCi/liter of 239 Pu in human urine. The method using neutron induced fission track analysis is to be made free of interference from uranium, the only naturally occurring element with an isotope which fissions with thermal neutrons. A simplified flow diagram for the method is shown in Figure 1. Briefly 239 Pu is coprecipitated quantitatively from urine with rhodozonic acid. The precipitate containing the 239 Pu is dissolved in HCl and is sequentially passed through two ion exchange columns and reduced in volume. The element is then deposited in a circular area on a thick polycarbonate detector and a thinner detector is placed over the circular deposit. The plastic detectors are then irradiated to a high thermal neutron fluence in a research reactor. The detectors are etched in a caustic solution for controlled times and temperatures in order to develop the fission tracks. Images of tracks are formed both on the thin and thick plastic detectors. Total tracks in the thinner detector are measured with a locally developed spark counter and in the thick plastic are measured by counting with a microscope. The results will be made quantitative by constructing a calibration curve for 239 Pu. 3 refs., 9 figs., 3 tabs

  8. Assessment of plutonium exposures in Rongelap and Utirik populations by fission track analysis of urine

    International Nuclear Information System (INIS)

    Sun, L.C.; Moorthy, A.R.; Kaplan, E.; Baum, J.W.; Meinhold, C.B.

    1994-01-01

    A nuclear device, code-named Bravo, detonated at Bikini Atoll at 6:45 a.m. on 1 March 1954, unexpectedly released a large amount of radioactivity. Over 40 years after this incident, the study of its impact on the radiological health and environmental safety of the residents of Rongelap and Utirik Atolls continues. In 1987, researchers at Brookhaven National Laboratory established a fission track analysis (FTA) method for low-level 239 Pu urinalysis. Two years later, a new shipboard protocol was developed for collecting 24-h radiologically clean urine samples. The purpose of this paper is to update information on the FTA method for measuring low-levels of plutonium, and to summarize results on the distribution of 239 Pu in the populations of Rongelap and Utirik between 1981--1991. Plutonium detection levels (99% confidence level) in these samples were 2--3 μBq, which is equivalent to 0.2--0.3 mSv effective dose equivalent (EDE) to age 70 for Marshallese. The latest 1991 FTA data indicate average EDE of 0.62 mSv and 1.6 mSv for the people of Rongelap and Utirik, respectively, which both are the highest values since 1988

  9. Fission track analysis method of urine plutonium and estimation of plutonium-239 internal dose to Marshallese

    International Nuclear Information System (INIS)

    Zhao Shixuan

    1995-01-01

    Bravo detonated at Bikini Atoll on the morning of March 1, 1954, unexpectedly released a large amount of radioactive fallout on the areas. Impact studies on the radiological health and safety of the residents living in the contaminated environments are still undergoing. For plutonium dose assessment, researchers at Brookhaven National Laboratory established a fission track analysis (FTA) method for low-level 239 Pu measurement. Furthermore, a new shipboard protocol was developed for collecting 24-h radiologically clean urine samples. The purposes of this paper are to update information on the FTA processes and to present a set of results on the 239 Pu measurements in the Marshallese populations (Rongelap and Utirik) between 1981-1991. The detection sensitivity of FTA method (99% confidence level) in these samples was 2-3 μBq which is equivalent to 0.2-0.3 mSv effective dose equivalent (EDE) to age 70 for the Marshallese. The latest 1991 FTA data indicate average EDE of 0.62 mSv and 1.6 mSv for the people of Rongelap and Utirik, respectively, which both are the highest values since 1988

  10. Cretaceous to present paleothermal gradients, central Negev, Israel: constraints from fission track dating

    International Nuclear Information System (INIS)

    Kohn, B.P.; Feinstein, S.; Eyal, M.

    1990-01-01

    Apatite and zircon fission track ages (FTA), vitrinite reflectance (VR) data and burial history curves were integrated for reconstruction of Early Cretaceous to present maximum thermal gradients in four deep boreholes in the central Negev, Isreal. The most complete data set is available from the Ramon 1 borehole. Supplementary data were obtained from Hameishar 1, Makhtesh Qatan 2, and Kurnub 1 boreholes. Between ca. 122-90 Ma the constraints on thermal gradient obtained from apatite FTA overlap with those derived from zircon FT and VR data, restricting them to 0 C km -l . Apatite FTA between 90 and 80 Ma in Ramon 1 and Hameishar 1 suggest rapid cooling at the time recorded or earlier. Constraints on thermal gradient history derived from these ages are considerably strengthened over a short time span. From 80 Ma to the present, FTA data indicate that gradients had probably decayed to present-day regional levels (ca. 20 0 C km -1 ) by Early Tertiary time. Thermal constraints derived from apatite FTA and VR data in Makhtesh Qatan 2 and Kurnub 1 boreholes are consistent with those obtained post-56 Ma for Ramon 1. For pre-56 Ma, only VR data are available and these indicate considerably lower maximum gradients than those obtained for the same time period from Ramon 1. This dichotomy reflects different Early Cretaceous-Early Tertiary thermal regimes between the northern and southern parts of the study area. (author)

  11. Assessment of plutonium exposures in Rongelap and Utirik populations by fission track analysis of urine

    International Nuclear Information System (INIS)

    Sun, L.C.; Moorthy, A.R.; Kaplan, E.; Baum, J.W.; Meinhold, C.B.

    1995-01-01

    A nuclear device, code-named Bravo, detonated at Bikini Atoll at 6.45 a.m. on 1 March 1954, unexpectedly released a large amount of radioactivity. Over 40 years after this incident, the study of its impact on the radiological health and environmental safety of the residents of Rongelap and Utirik Atolls continues. In 1987, researchers at Brookhaven National Laboratory established a fission track analysis (FTA) method for low-level 239 Pu urinalysis. Two years later, a new shipboard protocol was developed for collecting 24-h radiologically clean urine samples. The purpose of this paper is to update information on the FTA method for measuring low-levels of plutonium, and to summarize results on the distribution of 239 Pu in the populations of Rongelap and Utirik between 1981-1991. Plutonium detection levels (99% confidence level) in these samples were 2-3 μBq, which is equivalent to 0.2-0.3 mSv effective dose equivalent (EDE) to age 70 for Marshallese. The latest 1991 FTA data indicate average EDE of 0.62 mSv and 1.6 mSv for the people of Rongelap and Utirik, respectively, which both are the highest values since 1988. (author)

  12. Uranium content and fission track ages of some basalts from the FAMOUS area

    International Nuclear Information System (INIS)

    Storzer, Dieter; Selo, Madeleine

    1976-01-01

    The uranium contents of basalts from the rift valley in the Atlantic ocean near 37 deg N range between 75 ppb and 450 ppb. The fission track ages of these basalts range between 3x10 3 years and 6x10 5 years. They increase with distance from the axis of the median valley. Therefore, the locus of accretion of new crust seems to be restricted to a relatively narrow zone along the valley floor. In addition, the ages indicate that during the last 10 5 years the rate of accretion has been slower to the west than to the east. This indicates a migration of the active spreading center to the west by at least 1 km. the sea-floor spreading rates are high, up to 9cm/year, near the center of actual magmatic activity. They decrease with distance from the valley axis to 0.7 cm/year at about 2 km in the west respectively 1.5 cm/year at about 4 km in the east

  13. Distribution of uranium in dental porcelains by means of the fission track method

    International Nuclear Information System (INIS)

    Shimizu, Masami; Noguchi, Kunikazu; Moriwaki, Kazunari; Sairenji, Eiko

    1980-01-01

    Porcelain teeth, some of which contain uranium compounds for aesthetic purpose, have been widely used in dental clinics. Hazardous effects due to uranium radiation have been suggested by recent publications. In the previous study, the authors reported the uranium content of porcelain teeth and radiation dose by it. In this study, using the fission track method, the authors examined spatial distribution of uranium in dental porcelain teeth (4 brands) which were marketed in Japan. From each sample of porcelain tooth, a 1-mm-thick specimen was sliced, and uranium content was measured at every 0.19 mm from labial side to lingual side for making a uranium distribution chart. Higher uranium concentration was found in Trubyte Bioblend porcelain teeth (USA) and they showed almost uniform distribution of uranium, while those of the Japanese three brands indicated, in most case, comparatively lower concentration and found to be non-uniform distributions. Range of uranium concentration in these brands were N.D. -- 5.2 ppm (Shofu-Ace), N.D. -- 342 ppm (Shofu-Real), N.D. -- 47 ppm (G.C. Livdent) and N.D. -- 235 ppm (Trubyte Bioblend), respectively. (author)

  14. An extensive apatite fission-track study throughout the Northern Apennines Nappe belt

    International Nuclear Information System (INIS)

    Abbate, E.; Balestrieri, M.L.; Bigazzi, G.; Ventura, B.; Zattin, M.; Zuffa, G.G.

    1999-01-01

    This paper takes into consideration more than 100 apatite fission-track analyses on samples coming from an approximately west-east cross-section throughout the Northern Apennines. This collisional chain is made of structural units and nappes (Ligurian and Tuscan Nappe) accreted to the Adriatic Foreland during the Neogene, which overthrust the Miocene turbiditic successions of the Cervarola and Marnoso-arenacea Formations. Different cooling ages and degrees of annealing delineate different evolution histories for these units. Exhumation of the western outcrops of the Ligurian Nappe can be placed at 8 Ma and follows a first denudation event occurred in Eocene times. Timing of exhumation decreases eastwards. A break in this general trend is shown by the Apuan Alps, that occupy an intermediate position and yielded the youngest cooling ages. In the external part of the Marnoso-arenacea foredeep deposits this tendency could not be tested because total annealing of the apatite system has not been reached. In this case, modeling of data allows evaluating maximum burial temperatures

  15. A method for the measurement of fission rates in fast neutron fields using solid state track detectors

    International Nuclear Information System (INIS)

    Hansen, W.; Vogel, W.

    1984-04-01

    Solid state track detectors (SSTDs) are increasingly used for the registration of radiation in different fields of nuclear physics. Because of their small sizes and masses and the absence of any electronics during exposure SSTDs do not cause distortions in the system to be investigated and are useful for measurements at such places being difficult of access. The elaboration of a method is described for fission rate measurements in fast neutron fields applying SSTDs and different fissionable isotopes which were electrodeposited on stainless steel backings. Experiences of the electrodeposition and results of quality checks are presented. The evaluation of the etched tracks is performed with spark counter technique. The dependence of the counting result on essential influence parameters is discussed. (author)

  16. The spark counting of etched fission-fragment tracks in polycarbonate for a personal neutron dosimetry system

    International Nuclear Information System (INIS)

    Harrison, K.G.; Hancock, I.B.; Holt, P.D.; Wylie, J.W.

    1977-10-01

    A new type of personal neutron dosimeter, in which neutron-induced fissions in a thin 237 Np foil are detected by a polycarbonate track-detector, is under development at Harwell for use in a nuclear-fuel reprocessing plant. As part of the development programme, an experimental dosimeter, etching facility and spark counter have been used to study the spark-counting method for counting fission-fragment tracks in polycarbonate. Emphasis has been placed on developing operating procedures for the counter consistent with good overall reproducibility. Existing methods for the optimizing and testing of spark counters is briefly reviewed and a practical operational testing procedure is devised. The optimized system is found to be relatively foolproof in operation and gives good results in unskilled use as well as under carefully-controlled laboratory conditions. (author)

  17. Exhumation history of the NW Indian Himalaya revealed by fission track and 40Ar/39Ar ages

    Science.gov (United States)

    Schlup, Micha; Steck, Albrecht; Carter, Andrew; Cosca, Michael; Epard, Jean-Luc; Hunziker, Johannes

    2011-01-01

    New fission track and Ar/Ar geochronological data provide time constraints on the exhumation history of the Himalayan nappes in the Mandi (Beas valley) — Tso Morari transect of the NW Indian Himalaya. Results from this and previous studies suggest that the SW-directed North Himalayan nappes were emplaced by detachment from the underthrusted upper Indian crust by 55 Ma and metamorphosed by ca. 48–40 Ma. The nappe stack was subsequently exhumed to shallow upper crustal depths (

  18. Reconstructing Post-Carboniferous History of the Krkonoše Piedmont Basin Using Detrital Apatite Fission-Track Data

    Czech Academy of Sciences Publication Activity Database

    Martínek, K.; Svojtka, Martin; Filip, Jiří

    2006-01-01

    Roč. 20, - (2006), s. 91-92 ISSN 1210-9606. [Meeting of the Central European Tectonic Studies Group /4./. Zakopane, 19.04.2006-22.04.2006] Institutional research plan: CEZ:AV0Z30130516 Keywords : fission-track * Krkonoše * apatite Subject RIV: DB - Geology ; Mineralogy http://geolines.gli.cas.cz/fileadmin/volumes/volume20/G20-091b.pdf

  19. Timing of tertiary extension in the Southern Canadian Cordillera: constraints from fission-track analysis in the Shuswap metamorphic complex

    International Nuclear Information System (INIS)

    Lorencak, M.; Seward, D.; Burg, J.-P.

    1999-01-01

    Full text: Nine zircon and eighteen apatite fission-track analyses have been made in order to determine the low temperature cooling history of the Shuswap metamorphic core complex, western Canada. The zircons vary in apparent age from 53.9 ± 5.6 to 37.5 ± 5.0 Ma and the apatites from 48.5 ± 3.2 to 27.7 ± 3.4 Ma. In the footwall of the detachment faults defining the core complex, the cooling histories show a similarity until temperatures of ∼250 C were reached at about 45 Ma. From then on, activity on two normal faults, the Columbia River Fault and the Victor Creek Fault, controlled the regional cooling pattern. The ages and the combination of ages fall into four groups and on the basis of the fission-track data, we suggest that the region can now be divided into four thermotectonic units which are the result of differing tectonic controls during regional extension. Additionally, a complete cooling history of the Shuswap core complex can now be reconstructed, using constraints from U-Pb, Rb-Sr and K-Ar age data from several authors as well as the fission track results presented here. Copyright (1999) Geological Society of Australia

  20. Comparison through fission-track analysis of portions of Australia and Antarctica adjacent prior to continental drift

    International Nuclear Information System (INIS)

    Stump, E.; Fitzgerald, P.G.

    1990-01-01

    Australia and Antarctica have been reconstructed by the matching of three terranes in western Victoria with three terranes in northern Victoria Land. Apparent fission-track ages from granitic rocks of these matched regions are compared. In western Victoria, Australia, data reflect a history of slow cooling following intrusion in early to middle Paleozoic time. In northern Victoria Land, Antarctica, a complex history of cooling and uplift is indicated, with uplift of the present-day mountains commencing approximately 50 Ma. Fission tracks in apatites from most samples from northern Victoria Land were completely re-set to zero by the thermal effects of Jurassic tholeiitic magmatism. Apatite in three samples however, predate the Jurassic and were only partially re-set by this event. Apparent sphene fission-track ages indicate that the three terranes in northern Victoria Land have shared a common thermal history since the Devonian. With the exception of one small area in western Victoria, neither western Victoria nor northern Victoria Land data show a clear influence of rifting and breakup in the late Cretaceous. Overall, the data indicate that once the breakup of Australia and Antarctica had occurred, their thermal and tectonic histories evolved independently along differing paths. (author)

  1. Fission track ages on apatite of Bergell rocks from central Alps and Bergell boulders in Oligocene sediments

    International Nuclear Information System (INIS)

    Wagner, G.A.; Miller, D.S.

    1979-01-01

    Previous radiometric dating studies indicated that the Bergell region, in contrast to other regions of the Central Alps, experienced an early, rapid uplift, but with decreasing rate. Furthermore, there is also a geological record of the early uplift history of the Bergell granite by the existence of boulders which were derived from this granite and which occur in the Late Oligocene sediments of the Po plain. In this work the uplift history of the Bergell is studied in more detail by fission track dating of additional apatites from the Bergell region. Secondly, by determining apatite fission track ages the granitic boulders of the Po plain can be re-assigned to their original vertical position within the Bergell intrusive before erosion removed them in Late Oligocene time. A rather conservative estimate replaces them 6 km above the present morphology of the Bergell massif. Thus, the thickness of the Bergell granite must have been at least 8 km. Generally, fission track studies on boulders may become an important tool to study the vertical extent of mountain chains during the geological past. (Auth.)

  2. Identification of the source of manufacture of obsidian through the dating with the method of fission track

    International Nuclear Information System (INIS)

    Arias, C.; Bigazzi, G.; Bonadonna, F.P.; Radi, G.; Bernardes, C.; Hadler Neto, J.C.; Lattes, C.M.G.; Araya, A.M.O.; Oliveira, J.X.

    1986-01-01

    Identification of the source of manufacture of obsidian through the dating with the method of fission track. After a brief description of fission track dating method and of the problems related to its application to volcanic glasses, we show and discuss data about obsidians of geological origin from Mediterranean basin and Latin America and of archaeological origin found in prehistoric sites from Italian peninsula. The analysis of the results shows the excellent performance of fission track method to identify the provenance of obsidians of archaeological origin, provided important constributions both from the methodological pointo of view-excellent agreement between the two correction techniques of apparent ages, size-correction technique and plateau age -, as from the archaeological point of view - we could identify four possible sources of provenance in Italy, the obsidian from Monte Arci, Sardinia, the obsidian from Pahnarola island, the obsidian from Gabelloto, Lipari island and the obsidian from Balata dei Turchi, Pantelleria island; and it ca be shown that Lipari obsidian began to be used at a very antique phase of neolithic period. The data about Latin American samples, though fragmented, constitute in an inicial study promissing perpectives as it can be observed by the comparisions made with the data published by others authors about geologic and archaeologic samples from the same area. (Author) [pt

  3. The particle analysis based on FT-TIMS technique for swipe sample under the frame of nuclear safeguard

    International Nuclear Information System (INIS)

    Yang Tianli; Liu Xuemei; Liu Zhao; Tang Lei; Long Kaiming

    2008-06-01

    Under the frame of nuclear safeguard, the particles analysis for swipe sample is an advance mean to detect the undeclared uranium enriched facilities and undeclared uranium enriched activity. The technique of particle analysis based on fission track-thermal ionization mass spectrometry (FT-TIMS) for swipe sample have been built. The reliability and the experimental background for selecting particles consisting of uranium from swipe sample by FT method have been verified. In addition, the utilization coefficient of particles on the surface of swipe sample have also been tested. These works have provided the technique support for application in the area of nuclear verification. (authors)

  4. Mesozoic and Cenozoic uplift and exhumation of the Bogda Mountain, NW China: Evidence from apatite fission track analysis

    Directory of Open Access Journals (Sweden)

    Wenhao Tang

    2015-07-01

    Full Text Available Apatite fission track (AFT analysis on samples collected from a Paleozoic series is used to constrain the cooling history of the Bogda Mountain, northwest China. AFT ages range from 136.2 to 85.6 Ma and are younger than rock depositional ages and the mean confined track lengths (11.0–13.2 μm mostly showing unimodal distribution are shorten, indicating significant track-annealing. Thermal histories modeling based on the distribution of fission-track lengths combined with the regional geological data show that two rapid cooling phases occurred in the latest Jurassic–early Cretaceous and the Oligocene–Miocene. Those new data together with previous published data show that the AFT ages become younger from the southwest to northeast in the western Bogda Mountain and its adjacent areas. The fission-track ages of the southwest area are relatively older (>100 Ma, recording the earlier rapid uplift phase during the late Jurassic–Cretaceous, while the ages in the north piedmont of the Bogda Mountain (namely the northeast part are younger (<60 Ma, mainly reflecting the later rapid uplift phase in the Oligocene–Miocene. The trend of younger AFT ages towards the northeast might be explained by post-Cretaceous large-scale crustal tilting towards the southwest. In the thrust fault-dominated northern limbs of the Bogda Mountain, AFT ages reveal a discontinuous pattern with age-jumps across the major fault zones, showing a possible strata tilting across each thrust faults due to the thrust ramps during the Cenozoic. The two rapid uplift stages might be related to the accretion and collision in the southern margin of the Asian continent during the late Jurassic and late Cenozoic, respectively.

  5. Fission-track dating of South American natural glasses: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Bigazzi, G. [Istituto di Geoscienze e Georisorse, C.N.R., Via G. Moruzzi, 1, 56124 Pisa (Italy)]. E-mail: g.bigazzi@igg.cnr.it; Hadler Neto, J.C. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas SP (Brazil); Iunes, P.J. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, UNICAMP, 13083-970 Campinas SP (Brazil); Osorio Araya, A.M. [Departamento de Fisica, Quimica e Biologia, Universidade do Estado de Sao Paulo, UNESP, 19060-900 Presidente Prudente SP (Brazil)

    2005-12-01

    Although many glass-bearing horizons can be found in South American volcanic complexes or sedimentary series, only a relatively few tephra and obsidian-bearing volcanic fields have been studied using the fission-track (FT) dating method. Among them, the volcanics located in the Sierra de Guamani (east of Quito, Ecuador) were studied by several authors. Based upon their ages, obsidians group into three clusters: (1) very young obsidians, {approx}0.2Ma old (2) intermediate-age obsidians, {approx}0.4-{approx}0.8Ma old, and (3) older obsidians, {approx}1.4-{approx}1.6Ma old. The FT method is also an efficient alternative technique for identification of the sources of prehistoric obsidian artefacts. Provenance studies carried out in South America have shown that the Sierra de Guamani obsidian occurrences were important sources of raw material for tool making during pre-Columbian times. Glasses originated from these sources were identified in sites distributed over relatively wide areas of Ecuador and Colombia. Only a few systematic studies on obsidians in other sectors were carried out. Nevertheless, very singular glasses have been recognised in South America, such as Macusanite (Peru) and obsidian Quiron (Argentina), which are being proposed as additional reference materials for FT dating. Analyses of tephra beds interstratified with sedimentary deposits revealed the performance of FT dating in tephrochronological studies. A remarkable example is the famous deposit outcropping at Farola Monte Hermoso, near Bahia Blanca (Buenos Aires Province), described for the first time by the middle of the 19th century by Charles Darwin. Considering the large number of volcanic glasses that were recognised in volcanic complexes and in sedimentary series, South America is a very promising region for the application of FT dating. The examples given above show that this technique may yield important results in different disciplinary fields.

  6. Fission-track constraints on the thermal and tectonic evolution of the Apuseni Mountains (Romania)

    Science.gov (United States)

    Kounov, Alexandre; Schmid, Stefan M.

    2013-01-01

    New zircon and apatite fission-track (FT) data, including apatite thermal modelling, are combined with an extensive literature survey and reconnaissance-type structural fieldwork in the Eastern Apuseni Mountains. This leads to a better understanding of the complex structural and thermal history of a key area at the boundary between two megatectonic units in the Balkan peninsula, namely the Tisza and Dacia Mega-Units. Following Late Jurassic obduction of the Transylvanian ophiolites onto a part of the Dacia Mega-Unit, that is, the Biharia nappe system, both units were buried to a minimum of 8 km during late Early Cretaceous times when these units were underthrust below the Tisza Mega-Unit consisting of the present-day Codru and Bihor nappe systems. Tisza formed the upper plate during Early Cretaceous (`Austrian') east-facing orogeny. Turonian to Campanian zircon FT cooling ages (95-71 Ma) from the Bihor and Codru nappe systems and the Biharia and Baia de Arieş nappes (at present the structurally lowest part of the Dacia Mega-Unit) record exhumation that immediately followed a second Cretaceous-age (i.e. Turonian) orogenic event. Thrusting during this overprinting event was NW-facing and led to the overall geometry of the present-day nappe stack in the Apuseni Mountains. Zircon FT ages, combined with thermal modelling of the apatite FT data, show relatively rapid post-tectonic cooling induced by a third shortening pulse during the latest Cretaceous (`Laramian' phase), followed by slower cooling across the 120°-60 °C temperature interval during latest Cretaceous to earliest Paleogene times (75-60 Ma). Cenozoic-age slow cooling (60-40 Ma) was probably related to erosional denudation postdating `Laramian' large-scale updoming.

  7. Fission-track dating of South American natural glasses: an overview

    International Nuclear Information System (INIS)

    Bigazzi, G.; Hadler Neto, J.C.; Iunes, P.J.; Osorio Araya, A.M.

    2005-01-01

    Although many glass-bearing horizons can be found in South American volcanic complexes or sedimentary series, only a relatively few tephra and obsidian-bearing volcanic fields have been studied using the fission-track (FT) dating method. Among them, the volcanics located in the Sierra de Guamani (east of Quito, Ecuador) were studied by several authors. Based upon their ages, obsidians group into three clusters: (1) very young obsidians, ∼0.2Ma old (2) intermediate-age obsidians, ∼0.4-∼0.8Ma old, and (3) older obsidians, ∼1.4-∼1.6Ma old. The FT method is also an efficient alternative technique for identification of the sources of prehistoric obsidian artefacts. Provenance studies carried out in South America have shown that the Sierra de Guamani obsidian occurrences were important sources of raw material for tool making during pre-Columbian times. Glasses originated from these sources were identified in sites distributed over relatively wide areas of Ecuador and Colombia. Only a few systematic studies on obsidians in other sectors were carried out. Nevertheless, very singular glasses have been recognised in South America, such as Macusanite (Peru) and obsidian Quiron (Argentina), which are being proposed as additional reference materials for FT dating. Analyses of tephra beds interstratified with sedimentary deposits revealed the performance of FT dating in tephrochronological studies. A remarkable example is the famous deposit outcropping at Farola Monte Hermoso, near Bahia Blanca (Buenos Aires Province), described for the first time by the middle of the 19th century by Charles Darwin. Considering the large number of volcanic glasses that were recognised in volcanic complexes and in sedimentary series, South America is a very promising region for the application of FT dating. The examples given above show that this technique may yield important results in different disciplinary fields

  8. Application of fission track technique for estimation of uranium concentration in drinking waters of Punjab

    International Nuclear Information System (INIS)

    Prabhu, S.P.; Raj, Sanu S.; Sawant, P.D.; Kumar, Ajay; Sarkar, P.K.; Tripathi, R.M.

    2010-01-01

    Full text: Drinking water samples were collected from four different districts, namely Bhatinda, Mansa, Faridkot and Firozpur, of Punjab for ascertaining the U(nat.) concentrations. The samples were collected from bore wells, hand pumps, tube wells and treated municipal water supply. All these samples (235 nos.) collected were preserved and processed by following the international standard protocol and analyzed by Laser Fluorimetry. Results of analysis by laser fluorimetry have been already reported. To ensure accuracy of the data obtained by laser fluorimetry, few samples (10 nos) from each district were analyzed by alpha spectrometry as well as by fission track analysis (FTA) technique. FTA in solution media for uranium has been already standardized in Bioassay laboratory of Health Physics Division. Few of drinking water sample was directly transferred to polythene tube sealed at one end. Lexan detector with proper identification mark was immersed in the samples and the other open end of the tube was also heat-sealed. Two tubes containing samples and one containing uranium standard (80 ppb) were irradiated in the Pneumatic Carrier Facility (PCF) of DHRUVA reactor. The Lexan detectors were then chemically etched and tracks were counted under an optical microscope at 400X magnification. Concentration of uranium in sample was determined by comparison technique. Quality assurance was carried out by replicate analysis and by analysis of standard reference materials. Uranium concentration in these samples ranged from 3.2 to 60.5 ppb with an average of 28.8 ppb. A t-test analysis for paired data was done to compare the results obtained by FTA and those obtained by laser fluorimeter. The calculated value for t is -1.19, which is greater than the tabulated value of t for 40 observations (-2.02 at 95% confidence level). This shows that the results of the measurements carried out by the FTA and laser fluorimetry are not significantly different. The preliminary studies

  9. Solid State Track Recorder fission rate measurements in low power light water reactor pressure vessel mockups

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Roberts, J.H.; Kellogg, L.S.

    1985-01-01

    The results of extensive SSTR measurements made at the Pool Critical Assembly (PCA) facility at Oak Ridge National Laboratory have been reported previously. Measurements were made at key locations in PCA which is an idealized mockup of the water gap, thermal shield, pressure vessel geometry of a light water reactor. Recently, additional SSTR fission rate measurements have been carried out for 237-Np, 238-U, and 235-U in key locations in the NESTOR Shielding and Dosimetry Improvement Program (NESDIP) mockup facility located at Winfrith, England. NESDIP is a replica of the PCA facility, and comparisons will be made between PCA and NESDIP measurements. The results of measurements made at the engineering mockup at the VENUS critical assembly at CEN/SCK, Mol, Belgium will also be reported. Measurements were made at selected radial and azimuthal locations in VENUS, which models the in-core and near-core regions of a pressurized water reactor. Comparisons of absolute SSTR fission rates with absolute fission rates made with the Mol miniature fission chamber will be reported. Absolute fission rate comparisons have also been made between the NBS fission chamber, radiometric fission foils, and SSTRs, and these results will be summarized

  10. High temperature annealing of fission tracks in fluorapatite, Santa Fe Springs oil field, Los Angeles Basin, California

    Science.gov (United States)

    Naeser, Nancy D.; Crowley, Kevin D.; McCulloh, Thane H.; Reaves, Chris M.; ,

    1990-01-01

    Annealing of fission tracks is a kinetic process dependent primarily on temperature and to a laser extent on time. Several kinetic models of apatite annealing have been proposed. The predictive capabilities of these models for long-term geologic annealing have been limited to qualitative or semiquantitative at best, because of uncertainties associated with (1) the extrapolation of laboratory observations to geologic conditions, (2) the thermal histories of field samples, and (3) to some extent, the effect of apatite composition on reported annealing temperatures. Thermal history in the Santa Fe Springs oil field, Los Angeles Basin, California, is constrained by an exceptionally well known burial history and present-day temperature gradient. Sediment burial histories are continuous and tightly constrained from about 9 Ma to present, with an important tie at 3.4 Ma. No surface erosion and virtually no uplift were recorded during or since deposition of these sediments, so the burial history is simple and uniquely defined. Temperature gradient (???40??C km-1) is well established from oil-field operations. Fission-track data from the Santa Fe Springs area should thus provide one critical field test of kinetic annealing models for apatite. Fission-track analysis has been performed on apatites from sandstones of Pliocene to Miocene age from a deep drill hole at Santa Fe Springs. Apatite composition, determined by electron microprobe, is fluorapatite [average composition (F1.78Cl0.01OH0.21)] with very low chlorine content [less than Durango apatite; sample means range from 0.0 to 0.04 Cl atoms, calculated on the basis of 26(O, F, Cl, OH)], suggesting that the apatite is not unusually resistant to annealing. Fission tracks are preserved in these apatites at exceptionally high present-day temperatures. Track loss is not complete until temperatures reach the extreme of 167-178??C (at 3795-4090 m depth). The temperature-time annealing relationships indicated by the new data

  11. Cooling and denudation history of the Rokko area, southwest Japan, based on fission-track thermochronology

    International Nuclear Information System (INIS)

    Sueoka, Shigeru; Tagami, Takahiro; Tsutsumi, Hiroyuki; Hasebe, Noriko; Tamura, Akihiro; Arai, Shoji; Yamada, Ryuji; Matsuda, Tatsuo; Omura, Kentaro

    2010-01-01

    Quantitatively estimating denudation is generally difficult because it essentially involves the removal and loss of materials in situ. The denudation rate of mountainous areas in Japan has commonly been studied from the volume of sediment in a basin or catchment. Nonetheless, the availability of these methods is constrained spatially by upstream area and temporally by depositional age. In the last few decades, thermochronometric methods that evaluate thermal history using radiometric-dating methods have been used to evaluate the denudation and tectonic history of orogenic belts around the world. The advantages of thermochronometric methods are that we can calculate the denudation rate at each sampling point and that combining multiple methods and/or target minerals enables us to calculate denudation rates in multiple periods. However, thermochronometric methods have been applied to areas with extraordinarily high denudation rates in island arc areas such as Japan. Thus, the effectiveness of thermochronometric methods for estimating denudation rates in island arc areas has not been demonstrated. We applied apatite and zircon fission-track thermochronometry to granitic rock samples collected from outcrops and a borehole to estimate the tectonic history of the Rokko area, southwest Japan. Previous studies suggested that the Rokko Mountains have been uplifted by active faulting along their northern and southern margins during the Rokko movements, a Quaternary tectonic movement in the Kinki district. However, the tectonic history of the Rokko area prior to 1 Ma has not been revealed due to a lack of prevalent geologic markers. We estimated average denudation rates in various periods based on apatite and zircon FT ages and previously reported radiometric ages. We obtained denudation rates at about 0.04-0.10 mm/yr after about 30 Ma, 0.05-0.7 mm/yr during 50-30 Ma, 0.7-4.0 mm/yr during 70-50 Ma. The denudation rate after the deposition of the Kobe Group (36.9-30.4 Ma) is

  12. Apatite Fission-Track Analysis of the Middle Jurassic Todos Santos Formation from Chiapas, Mexico.

    Science.gov (United States)

    Abdullin, Fanis; Solé, Jesús; Shchepetilnikova, Valentina; Solari, Luigi; Ortega-Obregón, Carlos

    2014-05-01

    The Sierra de Chiapas (SCH), located in the south of Mexico, is a complex geological province that can be divided on four different lithological or tectonic areas: (1) the Chiapas Massif Complex (CMC); (2) the Central Depression; (3) the Strike-slip Fault Province, and (4) the Chiapas Fold-and-thrust Belt. The CMC mostly consists of Permian granitoids and meta-granitoids, and represents the basement of the SCH. During the Jurassic period red beds and salt were deposited on this territory, related to the main pulse of rifting and opening of the Gulf of Mexico. Most of the Cretaceous stratigraphy contains limestones and dolomites deposited on a marine platform setting during the postrift stage of the Gulf of Mexico rift. During the Cenozoic Era took place the major clastic sedimentation along the SCH. According the published low-temperature geochronology data (Witt et al., 2012), SCH has three main phases of thermo-tectonic history: (1) slow exhumation between 35 and 25 Ma, that affected mainly the basement (CMC) and is probably related to the migration of the Chortís block; (2) fast exhumation during the Middle-Late Miocene caused by strike-slip deformation that affects almost all Chiapas territory; (3) period of rapid cooling from 6 to 5 Ma, that affects the Chiapas Fold-and-thrust Belt, coincident with the landward migration of the Caribbean-North America plate boundaries. The two last events were the most significant on the formation of the present-day topography of the SCH. However, the stratigraphy of the SCH shows traces of the existence of earlier tectonic events. This study presents preliminary results of apatite fission-track (AFT) dating of sandstones from the Todos Santos Formation (Middle Jurassic). The analyses are performed with in situ uranium determination using LA-ICP-MS (e.g., Hasebe et al., 2004). The AFT data indicate that this Formation has suffered high-grade diagenesis (probably over 150 ºC) and the obtained cooling ages, about 70-60 Ma

  13. Response study of fission track detectors using two different moderator designs in a high-energy radiation field

    International Nuclear Information System (INIS)

    Mayer, S.; Boschung, M.; Fiechtner, A.; Fuerstner, M.; Wernli, C.

    2008-01-01

    Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement

  14. Response study of fission track detectors using two different moderator designs in a high-energy radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, S. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)], E-mail: Sabine.Mayer@psi.ch; Boschung, M.; Fiechtner, A. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Fuerstner, M. [CERN, CH-1211 Geneva 23 (Switzerland); Wernli, C. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2008-02-15

    Fission track detectors in the center of moderating spheres are routinely used to measure the ambient dose equivalent due to neutrons in the environmental dosimetry at Paul Scherrer Institut (PSI). Originally, the system was designed to cope with neutrons from skyshine effects. Later, the system was also adapted behind the shielding of PSI's accelerators. Nowadays, as a consequence of continuously upgrading accelerator energies and intensities, the neutron energy behind thick shielding can range from fractions of eV to about 1 GeV (e.g. at CERN). For this reason a measurement campaign in a high-energy stray radiation field at CERN's High-Energy Reference Field Facility (CERF) was initiated to study and compare the response of the already existing detector-moderator configuration and a new design, the 'GSI ball'. Employing an additional lead layer in a moderator sphere of 32.5 cm diameter, the GSI ball was primarily designed for the use with thermoluminescent based dosimeters in its center in order to optimize the response for the measurement of H*(10) to higher neutron energies. In this work, the measurement results for fission track detectors using two different radiator materials in the PSI and the GSI moderator are presented. Based on these studies, on the one hand, field calibration factors for the use in presumably similar high-energy fields around accelerators could be deduced. On the other hand, it could be shown that there is no need to replace the established PSI moderator by the GSI moderator since the combination of fission track detector and GSI moderator does not result in a significant sensitivity improvement.

  15. Study of uranium mineralization in rock samples from marwat range bannu basin by fission track analysis technique

    International Nuclear Information System (INIS)

    Qureshi, A.Z.; Ullah, K.; Ullah, N.; Akram, M.

    2004-07-01

    The Geophysics Division, Atomic Energy Minerals Centre (AEMC), Lahore has planned a uranium exploration program in Marwat Range, Bannu Basin. In this connection 30 thin sections of rock samples, collected from four areas; namely, Darra Tang, Simukili, Karkanwal and Sheikhillah from Marwat Range, and one from Salt Range were provided to Nuclear Geology Group of Physics Research Division, PINSTECH for the study of nature and mechanism of uranium mineralization These studies are aimed to help in designing uranium exploration strategy by providing the loci of uranium sources in the Marwat and Salt Ranges. The samples have been studied using fission track analysis technique. (author)

  16. Observations on the geometries of etched fission and alpha-recoil tracks with reference to models of track revelation in minerals

    International Nuclear Information System (INIS)

    Jonckheere, R.; Enkelmann, E.; Stuebner, K.

    2005-01-01

    The kinetic and atomistic theories of crystal growth and dissolution are used to interpret the shapes and orientations of fission-track, recoil-track and dislocation etch pits in tri-octahedral phlogopite and di-octahedral muscovite. An atomistic approach combined with symmetry considerations lead to the identification of the periodic bond chains that determine the etch pit morphologies and relative etch rates at a chemical level: O-Mg-O in phlogopite, O-Mg-O-Fe in biotite and O-Al-O in muscovite. Using first-order estimates of the bond strengths, it is possible to account for the relative track etch rates in these minerals. The reported, sometimes simultaneous, occurrence of triangular, polygonal and hexagonal etch pit contours in phlogopite, some of which violate the crystal symmetry, suggests that the cohesion of the phlogopite lattice is lost over a much larger radius than that of the track core around the trajectories of particles for which the energy loss exceeds a threshold value. This is interpreted as an indication of pronounced sublattice and anisotropic effects during track registration

  17. Measurement of the energy spectrum of {sup 252}Cf fission fragments using nuclear track detectors and digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, G.; Golzarri, J. I. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Castano, V. M. [UNAM, Centro de Fisica Aplicada y Tecnologia Avanzada, Boulevard Juriquilla 3001, Santiago de Queretaro, 76230 Queretaro (Mexico); Gaso, I. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Mena, M.; Segovia, N. [UNAM, Instituto de Geofisica, Circuito de la Investigacion Cientifica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2010-02-15

    The energy spectrum of {sup 252}Cf fission fragments was measured using nuclear track detectors and digital image analysis system. The detection material was fused silica glass. The detectors were chemically etched in an 8% HF solution. After experimenting with various etching time, it was found that the best resolution of the track diameter distribution was obtained after 30 minutes of etching. Both Gaussian and Lorentzian curves were fit to the track diameter distribution histograms and used to determine the basic parameters of the distribution of the light (N{sub L}) and heavy (N{sub H}) formed peaks and the minimum of the central valley (N{sub V}). Advantages of the method presented here include the fully-automated analysis process, the low cost of the nuclear track detectors and the simplicity of the nuclear track method. The distribution resolution obtained by this method is comparable with the resolution obtained by electronic analysis devices. The descriptive variables calculated were very close to those obtained by other methods based on the use of semiconductor detectors. (Author)

  18. New fission-track ages of mio-pliocene tuffs in the Sierras Pampeanas and Precordillera of Argentina

    International Nuclear Information System (INIS)

    Tabbutt, K.; Naeser, C.W.; Jordan, T.E.; Cerveny, P.F.

    1989-01-01

    Fission-track dates were determined for 18 volcanic tuff horizons located in nine Neogene foreland basin sequences distributed throughout the Precordillera and Sierras Pampeanas of Northwestern Argentina, an area of nearly horizontal subduction. These and other data indicate that a lower age limit for the sedimentary sequences studied is approximately 17 Ma. Therefore these fission-track dates constrain both the history of volcanic activity and the time of deposition in several foreland basins from the middle Miocene to Recent. Although the dates range from 3.6±0.8 Ma to 17.0±1.9 Ma, there is a marked increase in the number of ashes younger than 9 Ma. This implies that two distinct episodes of volcanic activity affected the region. The source of some of these tuffs is unknown but they are probably limited to the 'flat-slab' region between 27 deg and 32 deg S. Tuffs at Rio Blanco and Santa Florentina that are spatially associated with the Mogotes dacite domes of the Famatina Range represented magmatism bracketed from about 7 to 4 Ma in the region underlain by the flat-subducted plate. The stratigraphic relations in the basins show that the faulting that uplifted Sierra de Famatina was contemporaneous with the volcanism which reached the surface along the bounding faults. (Author) [es

  19. Multiple cooling episodes in the Central Tarim (Northwest China) revealed by apatite fission track analysis and vitrinite reflectance data

    Science.gov (United States)

    Chang, Jian; Qiu, Nansheng; Song, Xinying; Li, Huili

    2016-06-01

    Apatite fission track and vitrinite reflectance are integrated for the first time to study the cooling history in the Central Tarim, northwest China. The paleo-temperature profiles from vitrinite reflectance data of the Z1 and Z11 wells showed a linear relationship with depth, suggesting an approximately 24.8 °C/km paleo-geothermal gradient and 2700-3900 m of erosion during the Early Mesozoic. The measured apatite fission track ages from well Z2 in the Central Tarim range from 39 to 159 Ma and effectively record the Meso-Cenozoic cooling events that occurred in Central Tarim. Moreover, two cooling events at 190-140 Ma in the Early Jurassic-Early Cretaceous and 80-45 Ma in the Late Cretaceous-Paleocene revealed by measured AFT data and thermal modeling results are related to the collisions of the Qiangtang-Lhasa terranes and the Greater India Plate with the southern margin of the Eurasian Plate, respectively. This study provides new insights into the tectonic evolution of the Tarim Basin (and more broadly Central Asia) and for hydrocarbon generation and exploration in the Central Tarim.

  20. Thermal and exhumation history of Sakhalin Island (Russia) constrained by apatite U-Pb and fission track thermochronology

    Science.gov (United States)

    Glorie, Stijn; Alexandrov, Igor; Nixon, Angus; Jepson, Gilby; Gillespie, Jack; Jahn, Bor-Ming

    2017-08-01

    Sakhalin Island represents a key locality to study the tectonic evolution of the western Pacific. The island is located at the Amur-Okhotsk plate margin and records a complex thermotectonic history. Apatite double dating (U-Pb and fission track) and thermal history modelling were applied to three late Eocene granitoid massifs within central and southern Sakhalin: the Aniva, Okhotsk and Langeri complexes. Apatite U-Pb results yield consistent late Eocene (∼40-37 Ma) ages, suggesting rapid post-magmatic cooling. Apatite fission track results reveal bimodal age distributions with late Eocene - early Oligocene (∼38-33 Ma) and early Miocene (∼20-17 Ma) age populations that can be correlated with variations in Uranium and Chlorine concentrations. Thermal history modelling translates the AFT age bimodality into two-phase cooling histories. The timing of the early cooling phase (∼38-33 Ma) corresponds with the apatite U-Pb ages, indicating rapid cooling to at least ∼100 °C during the late Oligocene. The second cooling phase at ∼20-17 Ma cooled the samples to near-surface temperatures. Both cooling phases correspond with regional unconformities and subsequent accelerations in sedimentation rate, suggesting that cooling was a response to rapid exhumation. In addition, our data suggests that the studied terranes record differential exhumation with respect to the structural architecture. The Miocene exhumation pulse is coeval with the timing of transpressional fault displacement and the subsequent opening of the Kuril Basin.

  1. The potential of apatite fission track dating of vertical profiles in Namibia and the implications for passive margin evolution

    International Nuclear Information System (INIS)

    Raab, M.J.; Brown, R.W.; Cockburn, H.A.P.

    1999-01-01

    Full text: The on- and offshore geology of the Namibian passive continental margin has experienced kilometer scale erosion since South Atlantic opening in Lower Cretaceous times. A vertical apatite fission track profile of four samples in the Namibian highland has been analysed to constrain the low temperature thermal history of that area since the Pan-African Damara Orogeny at about 550 Ma. As a temperature sensitive thermochronological technique apatite fission track analysis is a powerful tool in constraining the low temperature history of rocks over a range of 60-110 deg C. These temperatures, depending on the geothermal gradient, equal a burial depth of 3-5 km so the method can reconstruct the cooling history of rocks as they approached the surface in response to erosion and tectonic processes. The four apparent apatite cooling ages are taken over a vertical distance of 300 m from the Windhoek Graben 40 km north of Windhoek. Forward modelling of the age and track length distribution has shown that these samples experienced high palaeotemperatures from ca. 90 to 95 deg C in the Late Cretaceous. This information was used to calculate the palaeogeothermal gradient at that time (20 deg C/km) which gives an estimate of the sedimentary cover of about 4.5 km which has been removed over a few million years in the Late Cretaceous. It was previously thought that the Namibian highland has been exposed at the surface more or less since the Permo-Carboniferous. In fact the samples provide evidence for a post Carboniferous reburial history of several kilometers followed by a short period of accelerated denudation in the Late Cretaceous at about 70 Ma. This might imply a far larger extent of the Etendeka flood basalts (132 Ma) and/or an underestimated sedimentary Karoo (Permian to Jurassic) thickness. The wider importance of these four data is that they detect the geomorphic impact of a global change of plate motion along the passive margin of Namibia which is known from a

  2. $\\bar{p}$-Induced Fission Studies with Plastic Track Detectors Using 4$\\pi$-Geometry

    CERN Multimedia

    2002-01-01

    % EMU20 \\\\ \\\\ The annihilation of a stopped antiproton on the surface of a target nucleus produces on the average five pions with a mean energy of 230~MeV. The high excitation of the nuclei with low angular momentum transfer can also be achieved by direct pion-nucleus interactions. The fission probabilities of highly excited nuclei can be explained on the basis of high energy limit of statistical theory. Previously the binary fission and higher multiplicity break-up of various nuclei caused by the absorption of pions has been studied by our group. The mechanism of nuclear excitation may still be the same when an antiproton annihilates in a nucleus and produces pions. It would be interesting to see whether the $\\bar{p}$ annihilation produces high enough excitation energies for nuclear phase-transition to take place. If so, then the fragmentation would overwhelm binary and ternary fission process. \\\\ \\\\The use of a highly sensitive plastic detector, CR-39, was made by our group in a number of studies involving ...

  3. Chrono-thermométrie par traces de fission : une perspective nouvelle pour la prospection pétrolière Chronothermometry by Fission-Track Dating: New Means for Petroleum Prospection

    Directory of Open Access Journals (Sweden)

    Storzer D.

    2006-11-01

    Full Text Available La propriété caractéristique des traces de fission d'enregistrer les paléotempératures offre la possibilité unique de caler des événements thermiques dans leur contexte géologique et donc de modéliser quantitativement les histoires thermiques des roches. Le thermomètre traces de fission-apatite enregistre les paléo-températures dans un intervalle compris entre 30 et 170°C, domaine qui inclut les températures généralement retenues pour la genèse optimale des hydrocarbures liquides. La formation, la maturation et la destruction des hydrocarbures, de la même façon que la guérison des traces latentes, sont fonction des deux paramètres temps et températures; en conséquence, l'étude détaillée de l'effacement progressif des traces latentes fossiles dans les apatites en fonction de leur profondeur dans un puits, conduit à des indications précises sur les variations de la température en fonction du temps à l'intérieur de la fenêtre à huile. Ces deux informations sont obtenues en combinant la datation traces de fission-isochrone et les analyses de longueurs des traces de fission. Le potentiel de la méthode des traces de fission dans son application à la reconstitution de l'histoire thermique des bassins sédimentaires est illustré à partir de l'analyse d'apatites détritiques provenant des bassins intérieur et côtier du Gabon d'une part et du bassin d'Otway en Australie du Sud d'autre part. The characteristic property of fission tracks to record paleotemperatures provides a unique possibility of setting thermal events in their geological context and hence of quantitatively modeling the thermal histories of rocks. The fission track apatite-thermometer records paleotemperatures in the interval between 30 and 170°C, a range that includes the temperatures generally considered to be required for the optimum formation of liquid hydrocarbons. The formation, maturation and destruction of hydrocarbons, as well as the

  4. Rapid Late Miocene Exhumation in the Central Alps, Constrained by (U-Th)/He and Fission Track Thermochronology

    Science.gov (United States)

    Aramowicz, A.; Cosca, M.; Stockli, D.; Farley, K.; Seward, D.

    2007-12-01

    Zircon and apatite (U-Th)/He thermochronological data together with apatite fission track analyses are used to explore uplift and exhumation of the western part of the Aar massif in the central Swiss Alps. A total of 27 samples were collected from the surface and underground, from the world's deepest tunnel (Loetschberg NEAT), with an overall elevation difference of almost 2500 m. Zircon (U-Th)/He ages range from 5.5 to 7.6 Ma, apatite fission track ages range from 5.7 to 6.5 Ma and apatite (U-Th)/He ages range from 3 to 5.5 Ma. All zircon age-elevation profiles from three traverses, show distinct brakes in slope that mark a drastic, 10-fold acceleration of exhumation at 6 ± 0.5 Ma ago (from 0.3 km/Ma to 3 km/Ma). The trend of fast exhumation appears to be maintained in the apatite fission track data while apatite (U-Th)/He ages suggest a return to moderate, apparent exhumation rates of 0.5 km/Ma. We propose that the accelerated exhumation may be linked to the Messinian desiccation of the Mediterranean. During that event, Mediterranean sea level dropped locally by as much as 3 km which accelerated erosion in the Alps. Consequently, the erosion in the Alps must have increased. If wedge mechanics are considered, the increased erosional flux reduced the active width of the orogen and, during latest convergence, deformation focused in the internal parts of the Alps, i.e. Aar massif. This interpretation implies a strong and prompt feedback between external forcing and tectonic response of the orogen. The slower exhumation rate apparent from the apatite (U-Th)/He data may reflect a decline in deformation. Alternatively, due to its low closure temperature, this system is prone to resetting by heat advected through hydrothermal circulation. This scenario needs further investigation but abundant hot-water (ca. 50 °C) discharge in the sampled tunnel is not uncommon.

  5. Dating by fission track method: study of neutron dosimetry with natural uranium thin films; Datacao com o metodo dos tracos de fissao: estudo da dosimetria de neutrons com filmes finos de uranio natural

    Energy Technology Data Exchange (ETDEWEB)

    Iunes, P J

    1990-06-01

    Fission track dating is described, focalizing the problem of the decay constant for spontaneous fission of {sup 238} U and the use of neutron dosimetry in fission track analysis. Experimental procedures using thin films of natural uranium as neutron dosimeters and its results are presented. The author shows a intercomparison between different thin films and between the dosimetry with thin film and other dosimetries. (M.V.M.). 52 refs, 12 figs, 9 tabs.

  6. Tectonic setting and uplift analysis of the Pangani rift basin in northern Tanzania using apatite fission track thermochronology

    International Nuclear Information System (INIS)

    Mbede, E.I.

    2001-01-01

    Thirty four new Apatite Fission Track (AFT) ages and 32 track length distributions from samples of basement rocks flanking the Pangani rift, East African Rift System (EARS) are presented, in an attempt to elucidate the uplift and erosion of the rift flanks. The ages fall in the range of 207±15 to 48±4 Ma, spanning from Early Jurassic to Early Tertiary. These ages are much younger than the last thermal event in the Mozambique belt that form the basement complex and are interpreted to represent the most recent tectonic events. Track length (TL) distributions suggest that uplift and erosion of the rift flanks are related to three different tectonic events, which are also recorded by the sedimentary units within the adjacent coastal basins. These included the Triassic/Early Jurassic, Late Cretaceous and Early Tertiary tectonic events. Erosion and isostatic rebound have modified the tectonically induced topographic patterns and the highly elevated plateaus flanking the Pangani rift represent an erosional surface referred to as the 'Gondwana surface' of eastern and central Africa. T he present AFT data suggest that initial exhumation of the 'Gondwana surface' from temperatures above 383.15 K to temperatures less than 333.15 K, in this area, took place during Early Jurassic times, but the final sub-aerial exposure of the surface did not take place until Early Tertiary. (author)

  7. Isotopic Determination of Nuclear Materials Using Nuclear Fission Track Registration Technique and Thermal Ionization Mass Spectrometric Technique

    International Nuclear Information System (INIS)

    Jeon, Young Sin; Pyo, Hyeong Yeol; Park, Yong Joon; Song, Kyu Seok; Kim, Won Ho; Jee, Kwang Yong

    2007-05-01

    It is very important to develope the technology for the determination of isotopic ratios of hot particles( 234 U, 235 U, 236 U etc.) detected from swipe samples of various nuclear facilities. This technology is highly competitive internationally and has to be established independently as long as our government maintains atomic energy and treats nuclear materials. In this text, sample pretreatment procedure, gamma-ray counting, alpha or fission track techniques, isotopic analysis of U and Pu, background problems and detection limits for mass determination, and their application to the real swipe sample were described with detailed procedure. This technology would contribute to the Korean economy's high growth rate as well as to superiority of government's leading research and development programs if successfully established

  8. Uranium content of coal ashes from Southern Brazil coal fueled power stations, by the fission track registration technique

    International Nuclear Information System (INIS)

    Morales, R.K.

    1981-01-01

    The feasibility of the application of the fission track registration technique for the determination of uranium in coal ashes was shown. The wet method was employed using as detector the Makrofol KG=10 μm, manufactured by Bayer. The coal ashes were originated from coal-fueled power stations localized in Southern Brazil. The results obtained ranged from 10 to 27 mg U/kg. Since the total error variation was from 18,4% to 23,8%, the method used was considered excellent. The determination of the uranium content in coal ashes is of considerable interest in environmental control in power stations, in their vicinity and wherever these ashes are used or stored. The technique used is the work proved to be very appropriate for the purpose aimed at. (Author) [pt

  9. Determination Of Uranium Concentration In Teeth Female Samples Using Fission Tracks In CR-39 From Different Countries

    International Nuclear Information System (INIS)

    Hummadi, S.S

    2010-01-01

    The present study was under taken to measure the uranium concentration in female teeth samples collected from different nationalities.The determination of uranium concentration in these samples has been done by using CR-39 track detector.The nuclear reaction is used as a source of nuclear fission fragments is (n, f) obtained by the bombardment of U-235 with thermal neutrons with flux (5*10 3 n/cm 2 .s) was used from (Am-Be) neutron source.The obtained results show the concentration is ranging from (0.58±0.7ppm) in Oman and Uae to (0.35±0.03ppm)in Iraqi for male, the uranium concentration was the highest in Oman and Uae for female

  10. Imprints left by natural radioactivity in geological materials: uranium fission tracks and thermoluminescence applications in earth sciences

    International Nuclear Information System (INIS)

    Broquet, P.; Chambaudet, A.; Rebetez, M.; Charlet, J.M.

    1994-01-01

    In a rock, all minerals which contain uranium are host to a number of spontaneous fission phenomena forming a single damaged area called a ''latent track'', observations of which may lead to dating, uranium mapping and finding paleo-geo-thermometers (thermal history, used in oil exploration). The radioactive elements during the decay process release energy which is trapped as electrons into the physical or chemical defects of the crystalline lattice; this energy can be later released by heating the mineral (thermic stimulated luminescence); the thermoluminescence is characterized by a glow which spectrum constitutes a typical feature of the mineral, its crystallization conditions and the subsequent evolution of the material. Natural and induced glow curve may be produced. 6 figs., 52 refs

  11. Zircon fission-track technique: a laboratory procedure adopted at the Institute of Geology, Academy of Sciences of the Czech Republic, v.v.i

    Czech Academy of Sciences Publication Activity Database

    Murakami, M.; Svojtka, Martin

    2007-01-01

    Roč. 20, - (2007), s. 13-19 ISSN N R&D Projects: GA MŠk 1K05030 Institutional research plan: CEZ:AV0Z30130516 Keywords : fission-track * zircon * Institute of Geology AS CR, v. v. i. Subject RIV: DB - Geology ; Mineralogy

  12. Cooling and erosion history of the Krkonoše Piedmont Basin (Bohemian Massif, Czech Republic) interpreted from apatite fission-track analysis

    Czech Academy of Sciences Publication Activity Database

    Svojtka, Martin; Filip, Jiří; Martínek, K.

    2005-01-01

    Roč. 7, - (2005), s. 4925-4926 ISSN 1607-7962. [European Geosciences Union, General Assembly. 24.04.2005-29.04.2005, Wien] R&D Projects: GA AV ČR KJB3111305 Institutional research plan: CEZ:AV0Z30130516 Keywords : Krkonoše * apatite * fission-track Subject RIV: DB - Geology ; Mineralogy

  13. Multiphase cooling and exhumation of the Krkonoše Piedmont Basin during Mesozoic - Cenozoic basin inversion based on apatite fission track analysis

    Czech Academy of Sciences Publication Activity Database

    Martínek, K.; Svojtka, Martin; Filip, Jiří

    2008-01-01

    Roč. 34, 4/6 (2008), s. 1353003-1353003 ISSN 0161-6951. [International Geological Congress /33./. 06.08.2008-14.08.2008, Oslo] R&D Projects: GA AV ČR KJB3111305 Institutional research plan: CEZ:AV0Z30130516 Keywords : fission track * apatite * Krkonoše Piedmont basin Subject RIV: DB - Geology ; Mineralogy

  14. Detrital zircon fission-track thermochronology and magnetic fabric of the Amaga Formation (Colombia): Intracontinental deformation and exhumation events in the northwestern Andes

    Czech Academy of Sciences Publication Activity Database

    Piedrahita, V. A.; Bernet, M.; Chadima, Martin; Sierra, G. M.; Marín-Cerón, M. I.; Toro, G. E.

    2017-01-01

    Roč. 356, JUL 1 2017 (2017), s. 26-42 ISSN 0037-0738 Institutional support: RVO:67985831 Keywords : Panama-Choco Block * Northern Andean Block * Amaga Formation * zircon fission track * anisotropy of magnetic susceptibility Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.373, year: 2016

  15. Provenance and post-depositional low-temperature evolution of the James Ross Basin sedimentary rocks (Antarctic Peninsula) based on fission track analysis

    Czech Academy of Sciences Publication Activity Database

    Svojtka, Martin; Nývlt, D.; Murakami, Masaki; Vávrová, J.; Filip, Jiří; Mixa, P.

    2009-01-01

    Roč. 21, č. 6 (2009), s. 593-607 ISSN 0954-1020 R&D Projects: GA MŠk 1K05030 Institutional research plan: CEZ:AV0Z30130516 Keywords : James Ross Island * Seymour Island * Cretaceous–Palaeogene succession * fission track dating * zircon * apatite Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.496, year: 2009

  16. Phanerozoic polycyclic evolution of the southwestern Angola margin: New insights for apatite fission track and (U-Th)/He methodologies

    Science.gov (United States)

    Venancio da Silva, Bruno; Hackspacher, Peter; Carina Siqueira Ribeiro, Marli; Glasmacher, Ulrich Anton

    2016-04-01

    The low-temperature thermochronology has been an important tool to quantify geological process in passive continental margins. In this context, the Angolan margin shows evidence of a polycyclic post-rift evolution marked by different events of uplift, basin inversion and changes in sedimentation rates to the marginal basins, which have controlled the salt tectonics and the hydrocarbon deposits (1,2,3,4). To understand the post break-up evolution of the southwestern Angola margin, it were collected outcrop samples for apatite fission track (AFT) and (U-Th)/He analysis ranging in elevation from 79 m to 1675 m from the coast toward the interior plateau in a profile between Namibe and Lubango cities. The area lies on the edge of Central and Southern Atlantic segments a few kilometers northward the Walvis ridge and encompasses the Archean and Proterozoic basement rocks of the Congo craton. The AFT ages ranging from 120.6 ± 8.9 Ma to 328.8 ± 28.5 Ma and they show a trend of increasing age toward the Great Escarpment with some exceptions. The partial mean track lengths (MTLs) vary between 11.77 ± 1.82 μm to 12.34 ± 1.13 μm with unimodal track length distributions (TDLs). The partial (U-Th)/He ages ranging from 104.85 ± 3.15 Ma to 146.95 ± 4.41 Ma and show the same trend of increasing ages landward, little younger than the AFT ages, which could be interpreted as a fast exhumation episode in Late Jurassic - Early Cretaceous times. The thermal histories modelling has been constrained with the kinetic parameters Dpar (5) and c-axis angle (6) by the software Hefty (7). Both AFT and (U-Th)/He thermal histories modelling indicate three episodes of denudation/uplift driven cooling: (a) from Late Jurassic to Early Cretaceous, (b) a smallest one in the Late Cretaceous and (c) from Oligocene-Miocene to recent, which are compatible with geophysical data of the offshore Namibe basin that estimate the greater thickness of sediments formed in the first and third episodes

  17. Inverted Apatite (U-Th)/He and Fission-track Dates from the Rae craton, Baffin Island, Canada and Implications for Apatite Radiation Damage-He Diffusivity Models

    Science.gov (United States)

    Ault, A. K.; Reiners, P. W.; Thomson, S. N.; Miller, G. H.

    2015-12-01

    Coupled apatite (U-Th)/He and fission-track (AFT) thermochronology data from the same sample can be used to decipher complex low temperature thermal histories and evaluate compatibility between these two methods. Existing apatite He damage-diffusivity models parameterize radiation damage annealing as fission-track annealing and yield inverted apatite He and AFT dates for samples with prolonged residence in the He partial retention zone. Apatite chemistry also impacts radiation damage and fission-track annealing, temperature sensitivity, and dates in both systems. We present inverted apatite He and AFT dates from the Rae craton, Baffin Island, Canada, that cannot be explained by apatite chemistry or existing damage-diffusivity and fission track models. Apatite He dates from 34 individual analyses from 6 samples range from 237 ± 44 Ma to 511 ± 25 Ma and collectively define a positive date-eU relationship. AFT dates from these same samples are 238 ± 15 Ma to 350 ± 20 Ma. These dates and associated track length data are inversely correlated and define the left segment of a boomerang diagram. Three of the six samples with 20-90 ppm eU apatite grains yield apatite He and AFT dates inverted by 300 million years. These samples have average apatite Cl chemistry of ≤0.02 wt.%, with no correlation between Cl content and Dpar. Thermal history simulations using geologic constraints, an apatite He radiation damage accumulation and annealing model, apatite He dates with the range of eU values, and AFT date and track length data, do not yield any viable time-temperature paths. Apatite He and AFT data modeled separately predict thermal histories with Paleozoic-Mesozoic peaks reheating temperatures differing by ≥15 °C. By modifying the parameter controlling damage annealing (Rmr0) from the canonical 0.83 to 0.5-0.6, forward models reproduce the apatite He date-eU correlation and AFT dates with a common thermal history. Results imply apatite radiation damage anneals at

  18. Study of the temperature effect on the surface of stainless steel using fission track technique

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, M M; Nagpaul, K K [Kurukshetra Univ. (India). Dept. of Physics

    1977-01-01

    Solid state track technique has been used to determine trace amounts of uranium in steel. Steel samples of the size 1 cm x 1 cm x 0.6 cm were ground, polished, heated to various temperatures ranging from room temperature to 900 deg C and then packed alternately with lexan detectors in an aluminium capsule for thermal neutron irradiation. After irradiation, lexan discs were removed and etched. Their surfaces were scanned under an optical microscope for measurement of track density. Uranium contents of the samples was found to vary from 6 ppm to 9 ppm.

  19. The measurement of the uranium content of crystals, glasses and meteorites with the fission track method

    International Nuclear Information System (INIS)

    Vartanian, R.

    1977-04-01

    In the present investigation, work has been carried out regarding the measurement of the uranium content of minerals, crystals and meteoritic samples from different parts of Iran. In this paper the method of inducing tracks from the 235 U indigenous to the Solid State Nuclear Track Detectors (SSNTDS) is described and new results have been attained. These are summarized as follows: Apatite between (4.16+-0.27) and (10.54+-0.84) ppm, Wulfnite=(4.90+-0.37) ppm, Quartz=(0.15+-0.02) ppm and Meteorite=(0.026+-0.003) ppm. (author)

  20. Fission track retention in minerals as a function of heating time during isothermal experiments

    International Nuclear Information System (INIS)

    Burchart, J.; Butkiewicz, T.; Dakowski, M.; Galazka-Friedman, J.

    1979-01-01

    The linear dependence of track retention on logarithm of heating time (at constant temperature) has been verified by statistical analysis of data on isothermal annealing of apatite. The other functions proposed (rho/rho 0 as a linearly decreasing function of exp t or t) fit the experimental data only within a limited range of heating times, where the shapes of all three are experimentally hard to resolve. The logarithmic relationship implies a memory of tracks for thermal events and creates a basis for methods of age corrections. (author)

  1. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    International Nuclear Information System (INIS)

    Brown, R.W.; Gleadow, A.J.W.; Rust, D.J.; Summerfield, M.A.; De Wit, M.C.J.

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of ∼ 14 μm with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 μm). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author)

  2. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.W.; Gleadow, A.J.W. (La Trobe Univ., Bundoora (Australia)); Rust, D.J.; Summerfield, M.A. (Edinburgh Univ. (UK)); De Wit, M.C.J. (De Beers Consolidated Mines Ltd., Kimberley (South Africa))

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of {approx} 14 {mu}m with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 {mu}m). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author).

  3. Thermochronology of the South American platform in the state of Sao Paulo, Brazil, through apatite fission tracks

    International Nuclear Information System (INIS)

    Tello Saenz, C.A.; Hadler Neto, J.C.; Iunes, P.J.; Guedes, S.; Hackspacher, P.C.; Ribeiro, L.F.B.; Paulo, S.R.; Osorio A, A.M.

    2005-01-01

    The fission-track method (FTM) in apatite was applied to 45 samples collected in the Serra da Mantiqueira (Mantiqueira mountain range), the Serra do Mar (Mar mountain range), regions next to these mountain ranges and the coastal region between Ubatuba and Santos in the State of Sao Paulo, Brazil, to study the thermochronology of the South American Platform in southeast Brazil and its influence on Santos and Campos basins. The data presented in this work complement the previously presented data on the same region (Tello Saenz et al., 2003. J. S. Am. Earth Sci. 15, 765-774) with 31 new samples analyzed. The weighted mean of the corrected ages from high Mantiqueira (around 1000m), (121+/-6)Ma, coincides with the South Atlantic opening. The fact that its thermal history starts at a relatively low temperature (∼80 deg. C) suggests that the age of ∼120Ma would be the formation age of Serra da Mantiqueira due to a rapid pulse, in which tracks had no time to be retained at the closure temperature, that is ∼120 deg. C. The Serra do Mar presents a more complicated thermal history, with several reactivations indicated by the changes in the slope of its cooling curve. The thermal histories obtained in the regions next to these mountain ranges are compatible with the results mentioned above. The Santos Basin has unconformities that agree with changes in the slope thermal histories of the studied region

  4. On the reproducibility of apatite fission-track plateau-age dating

    International Nuclear Information System (INIS)

    Poupeau, G.; Baitelli, R.; Berbert, M.; Fonseca, A.

    1985-01-01

    Duplicate measurements as well as published data show that plateau-age measurements on apatites have a reproducibility - when made in optical microscopy - generally better than +- 5%, which may be accounted for by statistical errors on track density measurement. (Author) [pt

  5. Laboratory-Scale Bismuth Phosphate Extraction Process Simulation To Track Fate of Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. JEFFREY; Lindberg, Michael J.; Jones, Thomas E.; Schaef, Herbert T.; Krupka, Kenneth M.

    2007-02-28

    Recent field investigation that collected and characterized vadose zone sediments from beneath inactive liquid disposal facilities at the Hanford 200 Areas show lower than expected concentrations of a long-term risk driver, Tc-99. Therefore laboratory studies were performed to re-create one of the three processes that were used to separate the plutonium from spent fuel and that created most of the wastes disposed or currently stored in tanks at Hanford. The laboratory simulations were used to compare with current estimates based mainly on flow sheet estimates and spotty historical data. Three simulations of the bismuth phosphate precipitation process show that less that 1% of the Tc-99, Cs-135/137, Sr-90, I-129 carry down with the Pu product and thus these isotopes should have remained within the metals waste streams that after neutralization were sent to single shell tanks. Conversely, these isotopes should not be expected to be found in the first and subsequent cycle waste streams that went to cribs. Measurable quantities (~20 to 30%) of the lanthanides, yttrium, and trivalent actinides (Am and Cm) do precipitate with the Pu product, which is higher than the 10% estimate made for current inventory projections. Surprisingly, Se (added as selenate form) also shows about 10% association with the Pu/bismuth phosphate solids. We speculate that the incorporation of some Se into the bismuth phosphate precipitate is caused by selenate substitution into crystal lattice sites for the phosphate. The bulk of the U daughter product Th-234 and Np-237 daughter product Pa-233 also associate with the solids. We suspect that the Pa daughter products of U (Pa-234 and Pa-231) would also co-precipitate with the bismuth phosphate induced solids. No more than 1 % of the Sr-90 and Sb-125 should carry down with the Pu product that ultimately was purified. Thus the current scheme used to estimate where fission products end up being disposed overestimates by one order of magnitude the

  6. Age and significance of core complex formation in a very curved orogen: Evidence from fission track studies in the South Carpathians (Romania)

    Science.gov (United States)

    Fügenschuh, B.; Schmid, S. M.

    2005-07-01

    Twenty-four new zircon and apatite fission track ages from the Getic and Danubian nappes in the South Carpathians are discussed in the light of a compilation of published fission track data. A total of 101 fission track ages indicates that the Getic nappes are generally characterized by Cretaceous zircon and apatite fission track ages, indicating cooling to near-surface temperatures of these units immediately following Late Cretaceous orogeny. The age distribution of the Danubian nappes, presently outcropping in the Danubian window below the Getic nappes, depends on the position with respect to the Cerna-Jiu fault. Eocene and Oligocene zircon and apatite central ages from the part of the Danubian core complex situated southeast of this fault monitor mid-Tertiary tectonic exhumation in the footwall of the Getic detachment, while zircon fission track data from northwest of this fault indicate that slow cooling started during the Latest Cretaceous. The change from extension (Getic detachment) to strike-slip dominated tectonics along the curved Cerna-Jiu fault allowed for further exhumation on the concave side of this strike-slip fault, while exhumation ceased on the convex side. The available fission track data consistently indicate that the change to fast cooling associated with tectonic denudation by core complex formation did not occur before Late Eocene times, i.e. long after the cessation of Late Cretaceous thrusting. Core complex formation in the Danubian window is related to a larger-scale scenario that is characterized by the NNW-directed translation, followed by a 90° clockwise rotation of the Tisza-Dacia "block" due to roll-back of the Carpathian embayment. This led to a complex pattern of strain partitioning within the Tisza-Dacia "block" adjacent to the western tip of the rigid Moesian platform. Our results suggest that the invasion of these southernmost parts of Tisza-Dacia started before the Late Eocene, i.e. significantly before the onset of Miocene

  7. Sequential fission process observed in the reaction (16.7 MeV/u) 238U + nat.Au using mica as dielectric track detector

    International Nuclear Information System (INIS)

    Shahzad, Muhammad Ikram; Qureshi, Imtinan Elahi; Manzoor, Shahid; Khan, Hameed Ahmed

    1999-01-01

    The evidence of sequential fission has been found in the heavy-ion reaction (16.7 MeV/u) 238 U + nat. Au, using muscovite mica as Dielectric Track Detector (DTD) placed in a 2π-geometry configuration. The reaction products originating from the interactions of 238 U ions with the atoms of gold were registered in the detector in the form of tracks and identified for performing a detailed kinematical analysis. For this purpose the spherical polar coordinates of the correlated tracks of the multipronged events have been analyzed on an event-by-event basis. Automatic, semi-automatic and manual measuring methods have been employed to collect and manipulate the track data. The known characteristics of binary and ternary events observed in the reaction have been used for the calibration of the detectors. The computed masses, Q-values and relative velocities of the reaction products determined in this analysis are compared with theoretical predictions based on sequential fission process. Agreement within one standard deviation with respect to the experimental values has been found for the majority of analyzed events. Therefore, it is concluded that three particles in the exit channel of the reaction are produced in two successive steps. In the first step of the reaction, two intermediate nuclei are formed as a result of an inelastic collision between projectile and target atoms while in the second step the fission of one of the intermediate nuclei of the previous step takes place. Furthermore no proximity effects have been observed

  8. Neogene tectonic evolution and exhumation of the southern Ecuadorian Andes: a combined stratigraphy and fission-track approach

    Science.gov (United States)

    Steinmann, Michael; Hungerbühler, Dominik; Seward, Diane; Winkler, Wilfried

    1999-06-01

    Coastal marine and continental sedimentary facies of Middle to Late Miocene age are exposed in the Andes of southern Ecuador (Cuenca, Girón-Santa Isabel, Loja, Malacatos-Vilcabamba and Catamayo-Gonzanamá Basins). The chronostratigraphy of the basin series was established by zircon fission-track dating on a total of 120 tephra layers. Subsequently, the timing of tectonic events was estimated through the well-dated stratigraphic sequences and intervening unconformities. Sedimentation from ≈15 to 9 Ma (termed Pacific Coastal Stage) was dominantly of coastal marine type, extending over an area far greater than the present basin perimeters. It ended when a period of east-west-oriented compression at ≈9.5-8 Ma exhumed the region, and sedimentation was then restricted to smaller basins (termed Intermontane Stage). These Late Miocene continental sediments were for the first time sourced from the west in the rising Western Cordillera. Apatite fission-track analysis was applied to some of the tephras in the Cuenca Basin and also to the older (Eocene, 42-35 Ma) Quingeo Basin series in order to quantify the basin histories with respect to timing and amount of burial and later exhumation. In the Quingeo Basin burial of the oldest sediments reached temperatures of ˜100°C at 18 Ma, when they started to cool down during a period of exhumation. This process preceded the Pacific Coastal Stage development of the other basins. In the Cuenca Basin, the oldest sediments were buried to temperatures of ca. 120°C by 9 Ma, when a period of inversion began and a phase of erosion was dominant. This timing correlates well with that estimated from structural evidence. At ca. 6 Ma the cooling rate slowed down and maybe even reverted to a small increase in temperature until 3 Ma, when the final stages of exhumation took place. Assuming a geothermal gradient of 35°C/km, total uplift for this part for Ecuador is about 6100 m over the last 9 million years. Assuming a steady state

  9. Analysis of trace uranium in human urine by using the fission track method

    International Nuclear Information System (INIS)

    Chen Huailu; Yang Huazhang; Zhao Dongzhi; Wang Kaixue

    1988-01-01

    In order to know the contents of uranium in human urine, urine samples from 10 healthy persons with different ages and sexes in Lanzhou area were analysed with the fisson track method. The results, in contrast with the contents of uranium in Yellow River water (in Lanzhou section), tap-water and rainwater, indicated that the content of uranium in human urine was lower than that in tap-water. From the ratio of uranium in human urine to that in tap-water, the maximum excreted rate of uranium from urine is evaluated to be 42.2%

  10. An improved FT-TIMS method of measuring uranium isotope ratios in the uranium-bearing particles

    International Nuclear Information System (INIS)

    Chen, Yan; Wang, Fan; Zhao, Yong-Gang; Li, Li-Li; Zhang, Yan; Shen, Yan; Chang, Zhi-Yuan; Guo, Shi-Lun; Wang, Xiao-Ming; Cui, Jian-Yong; Liu, Yu-Ang

    2015-01-01

    An improved method of Fission Track technique combined with Thermal Ionization Mass Spectrometry (FT-TIMS) was established in order to determine isotope ratio of uranium-bearing particle. Working standard of uranium oxide particles with a defined diameter and isotopic composition were prepared and used to review the method. Results showed an excellent agreement with certified values. The developed method was used to analyze isotope ratio of single uranium-bearing particle in swipe samples successfully. The analysis results of uranium-bearing particles in swipe samples accorded with the operation history of the origin. - Highlights: • The developed method was successfully applied in the analysis of real swipe sample. • Uranium-bearing particles were confined in the middle of track detector. • The fission tracks of collodion film and PC film could be confirmed each other. • The thickness of collodion film should be no more than about 60 μm. • The method could avoid losing uranium-bearing particles in the etching step.

  11. Apatite fission-track evidence of widespread Eocene heating and exhumation in the Yukon-Tanana Upland, interior Alaska

    Science.gov (United States)

    Dusel-Bacon, C.; Murphy, J.M.

    2001-01-01

    We present an apatite fission-track (AFT) study of five plutonic rocks and seven metamorphic rocks across 310 km of the Yukon-Tanana Upland in east-central Alaska. Samples yielding ???40 Ma AFT ages and mean confined track lengths > 14 ??m with low standard deviations cooled rapidly from >120??C to 40 Ma suggest partial annealing and, therefore, lower maximum temperatures (???90-105??C). A few samples with single-grain ages of ???20 Ma apparently remained above ???50??C after initial cooling. Although the present geothermal gradient in the western Yukon-Tanana Upland is ???32??C/km, it could have been as high as 45??C/km during a widespread Eocene intraplate magmatic episode. Prior to rapid exhumation, samples with ???40 Ma AFT ages were >3.8-2.7 km deep and samples with >50 Ma AFT ages were >3.3-2.0 km deep. We calculate a 440-320 m/Ma minimum rate for exhumation of all samples during rapid cooling. Our AFT data, and data from rocks north of Fairbanks and from the Eielson deep test hole, indicate up to 3 km of post-40 Ma vertical displacement along known and inferred northeast-trending high-angle faults. The predominance of 40-50 Ma AFT ages throughout the Yukon-Tanana Upland indicates that, prior to the post-40 Ma relative uplift along some northeast-trending faults, rapid regional cooling and exhumation closely followed the Eocene extensional magmatism. We propose that Eocene magmatism and exhumation were somehow related to plate movements that produced regional-scale oroclinal rotation, northward translation of outboard terranes, major dextral strike-slip faulting, and subduction of an oceanic spreading ridge along the southern margin of Alaska.

  12. Trace quantities of uranium in some indian chewing tobaccos as determined by fission track analysis

    International Nuclear Information System (INIS)

    Rana, N.P.S.; Singh, P.; Azam, A.; Naqvi, A.H.; Srivastava, D.S.

    1996-01-01

    The sandwiched pellet technique using Makrofol-E plastic track detectors has been employed to determine trace quantities of uranium in nine brands of flavored chewing tobaccos consumed by the Indian population. In this technique the nuclear reaction, 235 U(n,f), is used for the quantitative estimation of uranium. The maximum value of uranium (1.88 ppm) has been found in raw tobacco leaves (Surti), while the minimum (0.13 ppm) in Tulsi (Double Zero brand). Other seven brands showed intermediate values of U-contents which are also reported in this paper. These values are compared with the U-contents reported in the literature for other forms of tobaccos. (author). 9 refs., 2 figs., 1 tab

  13. Thermal history of the Krishna-Godavari basin, India: Constraints from apatite fission track thermochronology and organic maturity data

    Science.gov (United States)

    Sahu, Himansu S.; Raab, Matthias J.; Kohn, Barry P.; Gleadow, Andrew J. W.; Bal, Kiron D.

    2013-09-01

    The Krishna-Godavari (KG) basin, a passive margin Late Carboniferous to Holocene basin along the rifted east coast of India, includes the deltaic and inter-deltaic regions of the Krishna and Godavari rivers onshore and extends into the offshore. It is one of India's premier hydrocarbon-bearing basins. In an attempt to better understand the thermal history of the basin, apatite fission track (AFT) data has been obtained from six exploration wells (five onshore and one offshore). AFT thermal history models as well as other thermal indicators e.g. vitrinite reflectance (VR), Rock-Eval Tmax data reveal that the host rocks are currently at their maximum post-depositional temperatures and that any possible heating related to small-scale tectonism or rifting episodes in the basin bears little significance on the maturation of the sediments. In the case of one borehole (M-1) however, the organic maturity data reveals a period of Oligocene cooling across an unconformity when ∼1000 m of section was eroded due to falling sea-level. This information offers the potential for improved basin modeling of the KG basin.

  14. Pb, U, Ti, Hf and Zr distributions in zircons determined by proton microprobe and fission track techniques

    International Nuclear Information System (INIS)

    Clark, G.J.; Gulson, B.L.; Cookson, J.A.

    1979-01-01

    A proton microprobe has been used to determine Pb, Tl, Hf and Zr distributions across four single zircon crystals separated from a 'rapakivi' granite. The Pb and Zr data are quantitative: Pb and Tl concentrations were below the measurable limits for determinations in situ by most other techniques. The distribution of U in the same crystals was determined by the fission track technique. Limits on precision of U allow only a qualitative correlation of U and Pb, whereas the Tl and Pb correlation is more exactly determined. Zircons with distinct cores and overgrowths exhibited uniform Zr and Hf concentrations across the crystals, whereas the high U rims and 'inclusions' (domains) also had high Tl and Pb contents. Since almost all the Pb in these zircons is derived by radioactive decay of U, the Tl substitution has paralleled that of U. The results indicate that the high U domains are 'hot spots' rather than a separate mineral phase. The strong positive correlation of U and Pb indicates that there is little U daughter product migration relative to U, within the crystal. However, for the zircon population investigated here, the data are equivocal on the question of whether U addition to zircon crystals is associated with new zircon growth or not. In either case, the heterogeneous U and Pb distributions complicate any interpretations of U-Pb isotopic analysis for such zircon populations. (author)

  15. Geochronologic (K-Ar/Fission track) east-west profile of the Rio Grande do Sul shield

    International Nuclear Information System (INIS)

    Poupeau, G.; Baitelli, R.; Berbert, M.

    1985-01-01

    An E-W sampling was executed from Pelotas to Dom Pedrito, Rio Grande do Sul state, for K-Ar and Fission-track (FT) dating. Within the Dom Feliciano Orogenic Belt, from pelotas to Pinheiro Machado, K-Ar in biotites increase from 530m.y. to 655 m.y., with a discontinuity at the level of the approx.10Km wide Cangacu cataclastic Zone. In two samples from the Rio de La Plata Craton, at the western end of our profile, hornblendes present K-Ar ages of 1.555m.y. and 1.594m.y. FT ages in apatites record cooling of these minerals below 120 + - 20 0 C. From Pelotas to Pinheiro Machado, four sample present concordant ages at 270 + - 10m.y., whiel western most sample records a later event at 216 m.y. From the structure of plateau-ages it is suggested that the events dated are two positive tectonic pulses. Examination of the sedimentary of the Parana Basin confirms this interpretation. We therefore dated isotopically, for the firts time in Rio Grande do Sul basement, the ages of the two tectonic pulses wich affected the sedimentation in the Parana Basin. (Author) [pt

  16. Geochronologic (K-Ar/Fission Track) east-west profile of the Rio Grande do Sul shield

    International Nuclear Information System (INIS)

    Poupeau, G.; Baitelli, R.; Berbert, M.; Kawashita, K.

    1985-01-01

    An E-W sampling was executed from Pelotas to Dom Pedrito, Rio Grande do Sul State, for K-Ar and fission-track (FT) dating. Within the Dom Feliciano Orogenic Belt, from Pelotas to Pinheiro Machado, K-Ar in biotites increase from 530 m.y. to 655 m.y., with a discontinuity at the level of the 10 km wide Cangacu cataclastic Zone. In two samples from the Rio de La Plata Craton, at the Western end of our profile, hornblendes present K-Ar ages of 1.555 m.y and 1.594 m.y. FT ages in apatites record the cooling of these minerals below 120+- 20 0 C. From Pelotas to Pinheiro Machado, four samples present concordant ages at 270+ -10 m.y., while the western sample records a later event at 216 m.y. From the structure of plateau-ages it is suggested that the events dated are two positive tectonic pulses. Examination of the sedimentary of the Parana Basin confirms this interpretation. We therefore dated isotopically, for the first time in Rio Grande do Sul basement, the ages of the two tectonic pulses which affected the sedimentation in the Parana Basin. (Author) [pt

  17. Geology and zircon fission track ages of volcanic rocks in the western part of Hoshino gold area, Fukuoka Prefecture, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Belhadi, Ahmed; Himeno, Osamu; Watanabe, Koichiro; Izawa, Eiji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1999-12-01

    The Hoshino gold area is located in the western part of the Hohi volcanic zone, northern Kyushu. Volcanic rocks in this area vary from andesitic rocks in the north to dacite and rhyolite in the South. The basement is constituted by metamorphic rocks of pre-Cretaceous age. The volcanic rocks of Pliocene age were subdivided into eight volcanic units. Seven fission track ages of zircons from five volcanic units have been determined, using the external detector method. The age data obtained, combined with some previously reported ages, show that two main volcanic activities have occurred in the area. The first volcanic activity took place around 4.3 Ma, and resulted into the deposition of the Hoshino Andesite and the Ikenoyama Conglomerate. The second main volcanism started around 3.5 Ma, and was characterized by the eruption of the Shakadake Andesite and the Reiganji Andesite at the early stage, then, by more acidic rocks of the Takeyama Andesite, the Hyugami Dacite and the Kuroki Rhyolite at the later stage. The main volcanism in the area ceased around 2.6 Ma. (author)

  18. Unstable isotopes in a stable landscape?- Untangling Southern Africa's geological history with fission tracks and cosmogenic nuclides

    International Nuclear Information System (INIS)

    Belton, D.; Brown, R.; Fink, D.

    1998-01-01

    Full text: In the absence of direct evidence for burial and subsequent exposure of the land surface in the interior of Africa, researchers have argued for surface ages of several hundred million years. The proposition that landforms may have persisted at the surface for these extensive periods of time has a number of important implications. It suggests that the processes of tectonics and geomorphic evolution have been essentially absent for a period of up to 500 Ma. As a consequence, the persistence of these landscapes would require extremely low rates of weathering and erosion. Although this view of continental evolution has been widely held for several decades, recent studies suggest that continental interiors in Africa, Australia, Brazil and north America, have been subject to denudation in the order of several kilometres during the last 60 Ma. This study applies the complimentary techniques of apatite fission track and cosmogenic nuclide analysis, in an effort to measure both the long-term crustal-scale denudation and the short-term erosion rates, of which denudation is a function. We present preliminary data from the Zimbabwe Craton that illustrates the utility of such techniques in addressing both local and regional geological questions. The study provides a detailed picture of complex tectonic responses as well as large scale denudation over extended periods of time

  19. Determination of the uranium concentration in samples of raw, retorted and spent shale from Irati, Parana-Brazil, by the fission track registration technique

    International Nuclear Information System (INIS)

    Cabral, R.G.

    1981-02-01

    The feasibility of the determination of uranium in oil shale, by the fission track registration technique is studied. The wet and dry methods were employed, using a Bayer policarbonate, Makrofol KG, as detector. It was created a new variant of the dry method. The fission track registration technique was used in samples of raw, retorted and spent shale from Irati, Parana in Brazil, 16 μg U/g, 20 μg U/g and 20μg U/g were found, respectively, with a total error ranging from 19% to 20%. Some experimental results were included for illustration and comparison. The feasibility of the determination of uranium in oil shale from Irati was verified. (Author) [pt

  20. Mesozoic-Cenozoic tectonic evolution and its relation to sandstone-type uranium mineralization in northern Tarim area--Evidence from apatite fission track

    International Nuclear Information System (INIS)

    Liu Hongxu; Dong Wenming; Liu Zhangyue; Chen Xiaolin

    2009-01-01

    The apatite fission track dating and inversion result of geological thermal history of four rock specimens from Sawafuqi area and Talike area in northern Tarim Basin show that two areas uplifted at different ages. The apatite fission track ages of Sawafuqi range from 3.5 to 3.9 Ma, while the ages of Talike range from 53 to 59 Ma. The thermal history recorded by rock samples reveals that there are at least three prominent cooling phases since Late Cretaceous epoch. Detailed study was made on the division of uplifting stages during Mesozoic and Cenozoic tectonic evolution with the existing data in northern Tarim area. And new ideas on tectonic evolution and sandstone-type uranium mineralization have been put forward by combining with the sandstone-type uranium mineralization ages in this area.(authors)

  1. Thermal history of the multi-well experiment (MWX) site, Piceance Creek Basin, Northwestern Colorado, derived from fission-track analysis

    International Nuclear Information System (INIS)

    Kelley, S.A.; Blackwell, D.D.

    1990-01-01

    Fission-track analysis of apatite and zircon from 19 depth intervals in two drill holes at the MWX site in the Piceance Creek Basin, Colorado, is used to determine the burial and subsequent cooling history of the Upper Cretaceous Mesaverde Group and the Paleocene Wasatch Formation. The fission-track data, as well as available temperature, vitrinite reflectance, and geological information, indicate that the sampled sediments attained maximum burial at approximately 10 Ma, with maximum temperatures in the 150-200 0 C range. After 10 Ma the sediments began to cool during erosion related to the downcutting of the Colorado River, which lies just to the north of the MWX site. The heat flow in this area has remained relatively constant for the past 10 Ma. (author)

  2. Apatite fission track analysis for revealing tectonic events of the Bayinguole area in the west section of Eastern Kunlun Mountains, northern Qinghai-Tibet Plateau

    International Nuclear Information System (INIS)

    Chen Xiaoning; Yuan Wanming; Hao Nana; Duan Hongwei; Feng Yunlei; Zhang Aikui

    2014-01-01

    Background: Qimantage is an important tectonic metallogenic belt in western part of East Kunlun Mountain. It has experienced complex geological evolution, and significant mineralization. However, because of the plateau climate and inaccessibility, fewer research works have been done on this area, especially after Indo-sinian epoch. Purpose: Our work is to research tectonic activity, thermal history and uplifting around Bayinguole river in Qimantage belt. Methods: The apatite fission-track method was applied to research the tectonic setting, simulate the thermal history and calculate the uplift size and uplift speed. Results: A series of apatite fission track ages from granitoid samples in Bayinguole area of Eastern Kunlun Mountain were obtained, ranging from 120 Ma to 47 Ma that might be divided into three groups': 120-100 Ma, 67 Ma and 54-47 Ma. These ages reflected tectonic events in this area very well. Conclusions: The 120-100 Ma and 67 Ma ages present collision-convergences of Gangdese terrane and Himalayan terrane with their north-side terranes in Early Cretaceous and Late Cretaceous respectively. The ages of 54-47 Ma reflect post-orogenic stretching events in Eocene. Three stages of thermal evolution history are revealed by apatite fission track modeling in this area. Stage one 180-140 Ma is in the bottom temperature of apatite fission track anneal zone. Stage two 140-13 Ma records slow cooling. The last stage after 13 Ma records rapid cooling with temperature dropped 50℃. The uplifting ranges for these three stages are 1.0 km, 0.6 km and 1.4 km, respectively. The cumulative amount of uplift is about 3.0 km. The formula calculations for the 3 samples have their rock uplifts of 3623 m, 3317 m and 3769 m, respectively, averaging 3570 m, in accordance with the results based on the 3 stage thermal history. (authors)

  3. A study of the effect of natural radiation damage in a zircon crystal using thermoluminescence, fission track etching and X-ray diffraction

    International Nuclear Information System (INIS)

    Amin, Y.M.

    1989-01-01

    The natural radiation damage in zircon caused by the decay of uranium and thorium, present as impurities, is studied. The radiation damage is first gauged by etching the fission tracks. It is found that thermoluminescence (TL) sensitivity (defined as light output per unit test-dose) decreases as the radiation damage increases, suggesting a destruction of TL centers. The spacing d of the (112)-plane is also measured. It is also found that the d-value increases with radiation damage, suggesting the displacement of atoms from their normal lattice sites. However, as the track density increases beyond ≅ 3x10 6 tracks/cm 2 , the d-value remains at ≅ 2.52 A. By annealing the crystal, the displaced atoms are found to return to the original lattice sites, and this is followed by a reduction in d-value as well as the recovery of TL sensitivity. The fission track density also decreases and all the tracks disappear at the annealing temperature of ≅ 800 0 C. (orig.)

  4. Use of fission track analysis technique for the determination of MicroBequerel level of {sup 239}Pu in urine samples from radiation workers handling MOX fuel

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, J.R., E-mail: yadav_jogendra@rediffmail.co [Health Physics Laboratory, Health Physics Division, BARC, Tarapur 401502 (India); Rao, D.D.; Kumar, Ranjeet [Health Physics Laboratory, Health Physics Division, BARC, Tarapur 401502 (India); Aggarwal, S.K. [Fuel chemistry Division, BARC, Trombay, Mumbai 400085 (India)

    2011-07-15

    Fission track analysis (FTA) technique for the determination of {sup 239}Pu excreted through urine has been standardized using blank samples, tracer and {sup 239}Pu spikes. Double stage anion exchange separation protocol has been applied and an average radiochemical recovery of {sup 239}Pu of 18% was obtained. An average track registration efficiency of 11 tracks per {mu}Bq of {sup 239}Pu, irradiated to 0.35x10{sup 17} neutron fluence was established. Reagent blank urine samples from 11 controlled subjects were analyzed by FTA and an average of 149{+-}14 tracks was obtained. Minimum detectable activity of 34 {mu}Bq L{sup -1} of urine sample was obtained and will be useful for monitoring chronic exposure cases handling MOX fuel.

  5. Phanerozoic burial and exhumation history of southernmost Norway estimated from apatite fission-track analysis data and geological observations

    Science.gov (United States)

    Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.; Rasmussen, Erik S.

    2016-04-01

    We present new apatite fission-track analysis (AFTA) data from 27 basement samples from Norway south of ~60°N. The data define three events of cooling and exhumation that overlap in time with events defined from AFTA in southern Sweden (Japsen et al. 2015). The samples cooled below palaeotemperatures of >100°C in a major episode of Triassic cooling as also reported by previous studies (Rohrman et al. 1995). Our study area is just south of the Hardangervidda where Cambrian sediments and Caledonian nappes are present. We thus infer that these palaeotemperatures reflect heating below a cover that accumulated during the Palaeozoic and Triassic. By Late Triassic, this cover had been removed from the Utsira High, off SW Norway, resulting in deep weathering of a granitic landscape (Fredin et al. 2014). Our samples were therefore at or close to the surface at this time. Palaeotemperatures reached ~80°C prior to a second phase of cooling and exhumation in the Jurassic, following a phase of Late Triassic - Jurassic burial. Upper Jurassic sandstones rest on basement near Bergen, NW of our study area (Fossen et al. 1997), and we infer that the Jurassic event led to complete removal of any remaining Phanerozoic cover in the region adjacent to the evolving rift system prior to Late Jurassic subsidence and burial. The data reveal a third phase of cooling in the early Miocene when samples that are now near sea level cooled below palaeotemperatures of ~60°C. For likely values of the palaeogeothermal gradient, such palaeotemperatures correspond to burial below rock columns that reach well above the present-day landscape where elevations rarely exceed 1 km above sea level. This implies that the present-day landscape was shaped by Neogene erosion. This is in agreement with the suggestion of Lidmar-Bergström et al. (2013) that the near-horizontal Palaeic surfaces of southern Norway are the result of Cenozoic erosion to sea level followed by uplift to their present elevations in a

  6. Exhumation of Basement-cored Uplifts: Example of the Kyrgyz Range Quantified with Apatite Fission-track Thermochronology

    Science.gov (United States)

    Sobel, Edward R.; Oskin, Michael; Burbank, Douglas; Mikolaichuk, Alexander

    2005-01-01

    The Kyrgyz Range, the northernmost portion of the Kyrgyzstan Tien Shan, displays topographic evidence for lateral propagation of surface uplift and exhumation. The highest and most deeply dissected segment lies in the center of the range. To the east, topography and relief decrease, and preserved remnants of a Cretaceous regional erosion surface imply minimal amounts of bedrock exhumation. The timing of exhumation of range segments defines the lateral propagation rate of the range-bounding reverse fault and quantifies the time and erosion depth needed to transform a mountain range from a juvenile to a mature morphology. New apatite fission-track (AFT) data from three transects from the eastern Kyrgyz Range, combined with published AFT data, demonstrate that the range has propagated over 110 km eastwards over the last 7-11 Myr. Based on the thermal and topographic evolutionary history, we present a model for a time-varying exhumation rate driven by rock uplift and changes in erodability and the time scale of geomorphic adjustment to surface uplift. Easily eroded, Cenozoic sedimentary rocks overlying resistant basement control early, rapid exhumation and slow surface upliftrates. As increasing amounts of resistant basement are exposed, exhumation rates decrease while surface uplift rates are sustained or increase, thereby growing topography. As the range becomes high enough to cause ice accumulation and develop steep river valleys, fluvial and glacial erosion become more powerful and exhumation rates once again increase. Independently determined range-noma1 shortening rates have also varied over time, suggesting a feedback between erosional efficiency and shortening rate.

  7. Relationship between thermotectonic evolution of Serra do Mar mountain range and Santos Basin, SP, Brazil, accessed through fission track analysis in apatite

    International Nuclear Information System (INIS)

    Hadler, J.C; Tello, S.C.A; Iunes, P.J.; Guedes, S; Hackspacher, P; Paulo, S.R; Ribeiro, L.F.B

    2001-01-01

    Thermal evolution of tectonic units and its reflection on neighbouring basins adds importance to the study of some geological regions because this kind of process can be related to the origin of petroleum fields. During the last decade, thermochronology using the fission track method (FTM) in apatite was set up as an useful tool to obtain information from thermal histories (for instance, Rhorman et al., 1996; Amaral et al., 1997; Guedes et al., 2000). Thermal instability of fission tracks in some minerals is the basis of thermochronology by the FTM. In the case of apatite, there is a concordance in the temperature-time interval (∼70-110 o C for several tens of Ma) in which prehistoric forests were transformed in underground petroleum and a measurable shortening of fossil tracks. When spontaneous fission of a 238 U nucleus take place inside a mineral, a disarranged zone is created in the neighboring crystalline lattice (the latent track). This phenomenon is reversible since the atoms that were dislocated due to fission can come back to their original positions as consequence of thermal episodes of geological origin. This process can lead to partial or total reconstruction of the crystalline lattice around a latent track; it is named annealing in the literature. Fission tracks are continuously produced in apatite. Then, those prior to a thermal episode should present shorter lengths than those produced after it. In this way, by measuring the track length distribution at the optical microscope, after a suitable etching, one can obtain information about the thermal history of the region where an apatite sample was collected (Amaral et al., 1997). In spite of the effort carried out to understand track annealing kinetics (for instance, Carlson, 1990; Hadler et al., 2001), this phenomenon is not well known yet. To avoid this difficulty, annealing has been described using empirical models based on the best fitting of experimental data obtained in times compatible with

  8. Sequential fission process observed in the reaction (16.7 MeV/u) {sup 238}U + {sup nat.}Au using mica as dielectric track detector

    Energy Technology Data Exchange (ETDEWEB)

    Shahzad, Muhammad Ikram; Qureshi, Imtinan Elahi; Manzoor, Shahid; Khan, Hameed Ahmed

    1999-01-04

    The evidence of sequential fission has been found in the heavy-ion reaction (16.7 MeV/u) {sup 238}U + {sup nat.}Au, using muscovite mica as Dielectric Track Detector (DTD) placed in a 2{pi}-geometry configuration. The reaction products originating from the interactions of {sup 238}U ions with the atoms of gold were registered in the detector in the form of tracks and identified for performing a detailed kinematical analysis. For this purpose the spherical polar coordinates of the correlated tracks of the multipronged events have been analyzed on an event-by-event basis. Automatic, semi-automatic and manual measuring methods have been employed to collect and manipulate the track data. The known characteristics of binary and ternary events observed in the reaction have been used for the calibration of the detectors. The computed masses, Q-values and relative velocities of the reaction products determined in this analysis are compared with theoretical predictions based on sequential fission process. Agreement within one standard deviation with respect to the experimental values has been found for the majority of analyzed events. Therefore, it is concluded that three particles in the exit channel of the reaction are produced in two successive steps. In the first step of the reaction, two intermediate nuclei are formed as a result of an inelastic collision between projectile and target atoms while in the second step the fission of one of the intermediate nuclei of the previous step takes place. Furthermore no proximity effects have been observed.

  9. Uranium distribution and age pattern of some deep-sea basalts from the Entrecasteaux area, South-western Pacific: a fission-track analysis

    International Nuclear Information System (INIS)

    Selo, M.; Storzer, D.

    1981-01-01

    The eight glass samples analysed by means of the fission-track method were recovered from deep-sea dredge sites 314D, 316D, 323D and 325D in the SW Pacific. The bulk uranium contents of the fresh remnants of unweathered glasses range between 51 ppb and 108 ppb. One glass from site 316D with a U-content of 227 ppb might be part of a dike intrusion. The basalts from all four sites are altered to various extents. Ambient temperatures prevailing during these alteration processes are estimated to have been 1 to 5 0 C at sites 314D and 325D; about 10 0 C at site 323D; but 40 to 110 0 C at site 316D. The measured fission-track ages of sites 314D, 323D and 325D scatter between 34 Ma in the north and 20 Ma in the south. At site 316D, they are exceedingly low, being from 4.4 to =< 0.7 Ma. All these ages are thermally lowered and required correction. The ages corrected for thermally induced partial track-loss are given. From these ages and the site positions, a spreading rate is deduced for the northern part of the North Loyalty Plateau, which comes close to values estimated for slow-spreading ridges. (author)

  10. Evolution of the Chos Malal and Agrio fold and thrust belts, Andes of Neuquén: Insights from structural analysis and apatite fission track dating

    Science.gov (United States)

    Rojas Vera, E. A.; Mescua, J.; Folguera, A.; Becker, T. P.; Sagripanti, L.; Fennell, L.; Orts, D.; Ramos, V. A.

    2015-12-01

    The Chos Malal and Agrio fold and thrust belts are located in the western part of the Neuquén basin, an Andean retroarc basin of central-western Argentina. Both belts show evidence of tectonic inversion at the western part during Late Cretaceous times. The eastern part is dominated by late Miocene deformation which also partially reactivated the western structures. This work focuses on the study of the regional structure and the deformational event that shaped the relief of this part of the Andes. Based on new field work and structural data and previously published works a detailed map of the central part of the Neuquén basin is presented. Three regional structural cross sections were surveyed and balanced using the 2d Move™ software. In order to define a more accurate uplift history, new apatite fission track analyses were carried on selected structures. These data was used for new thermal history modeling of the inner part of the Agrio and Chos Malal fold and thrust belts. The results of the fission track analyses improve the knowledge of how these fold and thrust belts have grown trough time. Two main deformational events are defined in Late Cretaceous to Paleocene and Late Miocene times. Based on this regional structural analysis and the fission track data the precise location of the orogenic front for the Late Cretaceous-Paleocene times is reconstructed and it is proposed a structural evolution of this segment of the Andes. This new exhumation data show how the Late Cretaceous to Paleocene event was a continuous and uninterrupted deformational event.

  11. Thermo chronology by the fission track method of a passive marge (Ponta Grossa dome in south-eastern Brazil) and within a collision chain (external zone of the alpine arch in France)

    International Nuclear Information System (INIS)

    Medeiros Vignol Lelarge, M.L.

    1993-01-01

    The dating method by counting fission tracks on apatite (this rock is a geo-thermometer sensitive to weak temperature changes below 150 Celsius degrees) is an efficient tool for the thermal history of rocks. We have used this method in 2 different geological contexts: the Ponta Grossa dome in south-eastern Brazil and the alpine mountain in France. This dating method is based on the fact that some rocks like mica keep fossil remains of the passage of the fission products emitted during the simultaneous fission of uranium 238 present in the rock. This method requires the irradiation in a slow neutron flux of the sample because the initial quantity of uranium is unknown. The age t of the sample is given by the formula: t=(1/l 1 )*ln[1+(r s /r i )*(l 2 /l 1 )*F*σ*I] where: l 1 is the alpha decay constant of U 238 ; l 2 is the simultaneous fission decay constant of U 238 , r s is the number of fission tracks in the sample before the irradiation; r i is the number of fission tracks induced by the irradiation; F is the thermal neutron flux; σ is the thermal fission cross-section of U 235 ; and I is the isotopic rate U 235 /U 238 . This document is divided into 4 chapters. The first chapter presents the general principle of the method, the mechanisms capable of producing fission tracks and the techniques used to make these tracks visible with an optical microscope. The second chapter deals with the conditions of the irradiation and the calibration of the method. The 2 last chapters are dedicated to the applications to the 2 geological contexts. (A.C.)

  12. Use of 236Pu and 242Pu as a radiochemical tracer for estimation of Pu in bioassay samples by fission track analysis

    International Nuclear Information System (INIS)

    Sawant, Pramilla D.; Prabhu, Supreetha P.; Kalsi, P.C.

    2008-01-01

    236 Pu and 242 Pu are routinely used as radiochemical yield monitors in India for bioassay monitoring of occupational workers by alpha spectrometry. Fission Track Analysis (FTA) is also being standardized for trace level determination of Pu in bioassay samples. The present study, reports the utility of 236 Pu and 242 Pu as radiochemical tracers in estimation of Pu in bioassay samples by FTA technique. The advantages of using 236 Pu tracer in FTA over 242 Pu as well as the interference caused due to presence of 241 Pu in the bioassay samples of occupational workers handling power reactor grade Pu is discussed. (author)

  13. Summary of theory and techniques, sample selection and project organization for potassium-argon, rubidium-strontium and fission track dating and strontium isotope studies

    International Nuclear Information System (INIS)

    Adams, C.J.; Graham, I.J.; Seward, D.

    1987-02-01

    A brief outline is given of the theory and techniques of the potassium-argon, rubidium-strontium and fission-track dating methods and related isotope studies which are currently in use at the Institute of Nuclear Sciences, DSIR. Some limitations of each technique are set out in terms of age range and materials for dating, and the appropriate choice of various mineral and rock types and subsequent age interpretations are discussed. The organisation of project proposals and categories is described and procedures for sample submission and documentation are given

  14. Shaping the Australian crust over the last 300 million years: insights from fission track thermotectonic imaging and denudation studies of key terranes

    International Nuclear Information System (INIS)

    Kohn, B.P.; Gleadow, A.J.W.; Brown, R.W.; O'Sullivan, P.B.; Foster, D.A.; Gallagher, K.

    2002-01-01

    Apatite fission track thermochronology is a well-established tool for reconstructing the low-temperature thermal and tectonic evolution of continental crust. The variation of fission track ages and distribution of fission track lengths are primarily controlled by cooling, which may be initiated by earth movements and consequent denudation at the Earth's surface and/or by changes in the thermal regime. Using numerical forward-modelling procedures these parameters can be matched with time-temperature paths that enable thermal and tectonic processes to be mapped out in considerable detail. This study describes extensive Australian regional fission track datasets that have been modelled sequentially and inverted into time-temperature solutions for visualisation as a series of time-slice images depicting the cooling history of present-day surface rocks during their passage through the upper crust. The data have also been combined with other datasets, including digital elevation and heat flow, to image the denudation history and the evolution of palaeo-topography. These images provide an important new perspective on crustal processes and landscape evolution and show how important tectonic and denudation events over the last 300 million years can be visualised in time and space. The application of spatially integrated denudation-rate chronology is also demonstrated for some key Australian terranes including the Lachlan and southern New England Orogens of southeastern Australia, Tasmania, the Gawler Craton, the Mt lsa lnlier, southwestern Australian crystalline terranes (including the Yilgarn Craton) and the Kimberley Block. This approach provides a readily accessible framework for quantifying the otherwise undetectable, timing and magnitude of long-term crustal denudation in these terranes, for a part of the geological record previously largely unconstrained. Discrete episodes of enhanced denudation occurred principally in response to changes in drainage, base

  15. Potentialities and practical limitations of absolute neutron dosimetry using thin films of uranium and thorium applied to the fission track dating

    CERN Document Server

    Bigazzi, G; Hadler-Neto, J C; Iunes, P J; Paulo, S R; Oddone, M; Osorio, A M A; Zúñiga, A G

    1999-01-01

    Neutron dosimetry using natural uranium and thorium thin films makes possible that mineral dating by the fission-track method can be accomplished, even when poor thermalized neutron facilities are employed. In this case, the contributions of the fissions of sup 2 sup 3 sup 5 U, sup 2 sup 3 sup 8 U and sup 2 sup 3 sup 2 Th induced by thermal, epithermal and fast neutrons to the population of tracks produced during irradiation are quantified through the combined use of natural uranium and thorium films. If the Th/U ratio of the sample is known, only one irradiation (where the sample and the films of uranium and thorium are present) is necessary to perform the dating. However, if that ratio is unknown, it can be determined through another irradiation where the mineral to be dated and both films are placed inside a cadmium box. Problems related with film manufacturing and calibration are discussed. Special attention is given to the utilization of thin films having very low uranium content. The problems faced sugg...

  16. Temporal constraints on the tectonic evolution of Sierra De Famatina, northwestern Argentina, using the fission-track method to date tuffs interbedded in synorogenic clastic sedimentary strata

    Energy Technology Data Exchange (ETDEWEB)

    Tabbutt, K.D. (Dartmouth College, Hanover, NH (USA))

    1990-07-01

    Fission-track dates from seven volcaniclastic units allow time constraints to be placed on synorogenic clastic strata exposed along the flanks of Sierra de Famatina, northwest Argentina. Four formations are exposed along the western margin of Sierra de Famatina. The El Abra conglomerate is composed of clasts eroded from the basement exposed just to the west of Cadena de Paiman. The El Buey Formation contains sediments probably derived from the Precordillera fold and thrust belt to the west. Fission-track dates give a maximum age of 6 Ma for the deposition of both of these formations. The El Durazno Formation, deposited between 6 and 4 Ma, contains proximal volcaniclastic and other clastic rocks derived from the core of Sierra de Famatina. The Santa Florentina conglomerate was derived from the rising Sierra de Famatina and deposited in the past 4 m.y. Sierra de Famatima probably became a positive topographic feature approximately 6 Ma. Prior to that time this region was receiving fine-grained sediments from a distal fold and thrust belt and conglomerates from local basement uplifts. Minor extrusive events (Mogote Formation) coincide both spatially and temporally with deformation along the major reverse faults that control the uplift of Sierra de Famatina. Minimum mean uplift rates calculated for Sierra de Famatina are 0.8 {plus minus} 0.1 mm/yr over a 6.8 m.y. interval.

  17. Long-term landscape evolution of the South Atlantic "passive" continental margin in Eastern Argentina using apatite fission-track thermochronology

    Science.gov (United States)

    Pfister, Sabrina; Kollenz, Sebastian; Glasmacher, Ulrich A.

    2015-04-01

    To understand the evolution of the "passive" continental margin in Argentina low temperature thermochronology is an appropriate method, which might lead to new insights in this area. The Tandilia System, also called Sierras Septentrionales, is located south of the Río de la Plato Craton in eastern Argentina in the state of Buenos Aires. North of the hills the Salado basin is located whereas the Claromecó basin is situated south of the mountain range. In contrary to most basins along the South American "passive" continental margin, the Tandilia-System and the neighbouring basins trend perpendicular to the coast line. The topography is fairly flat with altitudes up to 350 m. The igneous-metamorphic basement is pre-Proterozoic in age and build up of mainly granitic-tonalitic gneisses, migmatites, amphibolites, some ultramafic rocks and granitoid plutons. It is overlain by a series of Neoproterozoic to early Paleozoic sedimentary rocks (Cingolani 2011), like siliciclastic rocks, dolostones, shales and limestones (Demoulin 2005). The aim of the study is to quantify the long-term landscape evolution of the "passive" continental margin in eastern Argentina in terms of thermal, exhumation and tectonic evolution. For that purpose, samples were taken from the basement of the Sierra Septentrionales and analyzed with the apatite fission-track method. Further 2-D thermokinematic modeling was conducted with the computer code HeFTy (Ketcham 2005; Ketcham 2007; Ketcham et al. 2009). Because there are different hypotheses in literature regarding the geological evolution of this area two different models were generated, one after Demoulin et al. (2005) and another after Zalba et al.(2007). All samples were taken from the Neoproterozoic igneous-metamorphic basement. Apatite fission-track ages range from 101.6 (9.4) to 228.9 (22.3) Ma, and, therefore, are younger than their formation age, indicating all samples have been thermally reset. Six samples accomplished enough confined

  18. The thermal history of the Karoo Moatize-Minjova Basin, Tete Province, Mozambique: An integrated vitrinite reflectance and apatite fission track thermochronology study

    Science.gov (United States)

    Fernandes, Paulo; Cogné, Nathan; Chew, David M.; Rodrigues, Bruno; Jorge, Raul C. G. S.; Marques, João; Jamal, Daud; Vasconcelos, Lopo

    2015-12-01

    The Moatize-Minjova Basin is a Karoo-aged rift basin located in the Tete Province of central Mozambique along the present-day Zambezi River valley. In this basin the Permian Moatize and Matinde formations consist of interbedded carbonaceous mudstones and sandstones with coal seams. The thermal history has been determined using rock samples from two coal exploration boreholes (ca. 500 m depth) to constrain the burial and exhumation history of the basin. Organic maturation levels were determined using vitrinite reflectance and spore fluorescence/colour. Ages and rates of tectonic uplift and denudation have been assessed by apatite fission track analysis. The thermal history was modelled by inverse modelling of the fission track and vitrinite reflectance data. The Moatize Formation attained a coal rank of bituminous coals with low to medium volatiles (1.3-1.7%Rr). Organic maturation levels increase in a linear fashion downhole in the two boreholes, indicating that burial was the main process controlling peak temperature maturation. Calculated palaeogeothermal gradients range from 59 °C/km to 40 °C/km. According to the models, peak burial temperatures were attained shortly (3-10 Ma) after deposition. Apatite fission track ages [146 to 84 Ma (Cretaceous)] are younger than the stratigraphic age. Thermal modelling indicates two episodes of cooling and exhumation: a first period of rapid cooling between 240 and 230 Ma (Middle - Upper Triassic boundary) implying 2500-3000 m of denudation; and a second period, also of rapid cooling, from 6 Ma (late Miocene) onwards implying 1000-1500 m of denudation. The first episode is related to the main compressional deformation event within the Cape Fold Belt in South Africa, which transferred stress northwards on pre-existing transtensional fault systems within the Karoo rift basins, causing tectonic inversion and uplift. During the Mesozoic and most of the Cenozoic the basin is characterized by very slow cooling. The second period

  19. Tim Berners-Lee during the WSIS

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Tim Berners-Lee stands in front of the first web server at the Geneva Palexpo during the World Summit on the Information Society (WSIS) in 2003. Tim Berners-Lee developed the first network and server system that lead to the World Wide Web.

  20. New insights on the geological evolution of the continental margin of Southeastern Brazil derived from zircon and apatite (U-Th-Sm)/He and fission-track data

    Science.gov (United States)

    Krob, Florian; Stippich, Christian; Glasmacher, Ulrich A.; Hackspacher, Peter

    2017-04-01

    New insights on the geological evolution of the continental margin of Southeastern Brazil derived from zircon and apatite (U-Th-Sm)/He and fission-track data Krob, F.C.1, Stippich, C. 1, Glasmacher, U.A.1, Hackspacher, P.C.2 (1) Institute of Earth Sciences, Research Group Thermochronology and Archaeometry, Heidelberg University, INF 234, 69120, Heidelberg, Germany (2) Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista, Av. 24-A, 1515 Rio Claro, SP, 13506-900, Brazil Passive continental margins are important geoarchives related to mantle dynamics, the breakup of continents, lithospheric dynamics, and other processes. The main concern yields the quantifying long-term lithospheric evolution of the continental margin between São Paulo and Laguna in southeastern Brazil since the Neoproterozoic. We put special emphasis on the reactivation of old fracture zones running into the continent and their constrains on the landscape evolution. In this contribution, we represent already consisting thermochronological data attained by fission-track and (U-Th-Sm)/He analysis on apatites and zircons. The zircon fission-track ages range between 108.4 (15.0) and 539.9 (68.4) Ma, the zircon (U-Th-Sm)/He ages between 72.9 (5.8) and 427.6 (1.8) Ma whereas the apatite fission-track ages range between 40.0 (5.3) and 134.7 (8.0) Ma, and the apatite (U-Th-Sm)/He ages between 32.1 (1.52) and 92.0 (1.86) Ma. These thermochronological ages from metamorphic, sedimentary and intrusive rocks show six distinct blocks (Laguna, Florianópolis, Curitiba, Ilha Comprida, Peruibe and Santos) with different evolution cut by old fracture zones. Furthermore, models of time-temperature evolution illustrate the differences in Pre- to post-rift exhumation histories of these blocks. The presented data will provide an insight into the complex exhumation history of the continental margin based on the existing literature data on the evolution of the Paraná basin in Brazil and the latest

  1. Use of combined alpha-spectrometry and fission track analysis for the determination of 240Pu/239Pu ratios in human tissue

    International Nuclear Information System (INIS)

    Love, S.F.; Filby, R.H.; Glover, S.E.; Stuit, D.B.; Kathren, R.L.

    1998-01-01

    Plutonium and other actinides were determined in human autopsy tissues of occupationally exposed workers who were registrants of the United States Transuranium and Uranium Registries (USTUR). In this study, Pu was purified and isolated from Am, U and Th, after drying and wet-ashing of the tissues, and the addition of 238 Pu as a radiotracer. After electrodeposition onto vanadium planchets, the 239+240 Pu activity was determined by alpha-spectrometry. A fission track method was developed to determine 239 Pu in the presence of 238 Pu and 240 Pu, using Lexan TM polycarbonate detectors. Combining the two techniques allowed the determination of the 240 Pu/ 239 Pu activity and atom ratios. Data from selected USTUR cases are presented. (author)

  2. Determination of uranium content in dental porcelains by means of the fission track method and estimation of radiation dose to oral mucosa by radioactive elements

    International Nuclear Information System (INIS)

    Sairenji, E.; Moriwaki, K.; Shimizu, M.; Noguchi, K.

    1980-01-01

    Porcelain teeth, some of which contain uranium compounds for aesthetic purpose, have been widely used in dental clinics. Hazardous effects due to uranium radiation have been suggested in recent publications. In the present study uranium concentrations were determined in four major brands of porcelain teeth marketed in Japan using the fission track method, and the absorbed doses to oral tissued were calculated. Average uranium concentrations of the brands studied were determined to be 3.6 ppm (0.33-10 ppm, Japan), 18 ppm (0.69-81 ppm, Japan), 9.4 ppm (2.5-14 ppm, Japan) and 82 ppm (11-205 ppm, U.S.), respectively. The corresponding dose equivalents at the surface of oral mucosal membrane were 2.9 rem yr -1 . 14 rem yr -1 , 7.6 rem yr -1 and 66 rem yr -1 . (author)

  3. Fission track and petrostructural analysis of carbonatic massif of Tamazert ( high central Atlas, Morocco) and neogene reactivation of the north-atlasic fault

    International Nuclear Information System (INIS)

    Ziad, N.; Khazrouni, S.; Tayebi, M.; Bouabdli, A.; Poupeau, G.

    2001-01-01

    The uranium fission-track dating method is used in geochronological survey of basic apatites extracted from the Tamazert complex. The result of this survey coupled with those of petrostructural analysis of this massif enabled as to distinguish three age groups: 32.4 Myr, 23.3 Myr and 12.6 Myr. The first age corresponds to the setting up of the massif, whereas the two other ages indicate later emissions. The setting up of the sill whose age is 12.6 Myr induced a partial rejuvenation of the emission age og the massif. This late volcanic emission is probably related to the north-atlasic fault activity. 4 figs., 1 tab., 30 refs. (au)

  4. Determination of uranium content in dental porcelains by means of the fission track method and estimation of radiation dose to oral mucosa by radioactive elements

    International Nuclear Information System (INIS)

    Sairenji, Eiko; Moriwaki, Kazunari; Shimizu, Masami; Noguchi, Kunikazu; Anzai, Ikuro.

    1979-01-01

    Porcelain teeth, some of which contained uranium compounds for aesthetic purpose, have been widely used in dental clinics. Recently, the hazardous effects by uranium radiation were suggested. In the present study, the authors carried out the determination of uranium concentrations of four major brands of porcelain teeth marketed in Japan using the fission track method, and the absorbed doses of oral tissues were calculated by the authors' introduced formula for calculation of alpha radiation. Average uranium concentrations of the brands studied were determined 3.6 ppm (0.33 - 10 ppm, Japan), 18 ppm (0.69 - 81 ppm, Japan), 9.4 ppm (2.5 - 14 ppm, Japan) and 82 ppm (11 - 205 ppm, U.S.A.), respectively. The corresponding dose equivalents at the surface of oral mucosal membrane were 2.9 rem y -1 , 14 rem y -1 , 7.6 rem y -1 and 66 rem y -1 . (author)

  5. Comparisons of fission track age-determination and radioactivation analysis among radiation fields. Characteristic values for pneumatic tube, JRR-3M PN2

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Tatsuro [Kagoshima Univ. (Japan). Faculty of Education; Tomura, Kenji

    1996-01-01

    It is necessary for Fission track age determination and radioactivation analysis to define the energy spectrum of a reactor neutron as the basis for calculating the nuclear reaction rate. This study was made aiming to define the spectrum for PN2 pneumatic tube of No. 3 plant of Japan Atomic Energy Research Institute (JAERI). Characteristics such as conventional flux, cross reaction, neutron temperature and integral fast flux were examined for 3 facilities; JRR-2, JRR-4 and JRR-3M. And the neutron spectrum for each facility was estimated based on the assumptions; Maxwell distribution for thermal neutrons, 1/E for intermediate neutrons and Watt`s formula for fast neutrons. The present results showed that the spectrum for JRR-3M, PN2 was discontinuous in the range from the intermediate to the fast neutron, whereas those for other facilities were found considerably improved. (M.N.)

  6. A criticism of the paper entitled 'A practical method of estimating standard error of the age in the Fission Track Dating method' by Johnson, McGee and Naeser

    International Nuclear Information System (INIS)

    Green, P.F.

    1981-01-01

    It is stated that the common use of Poissonian errors to assign uncertainties in fission-track dating studies has led Johnson, McGee and Naeser (1979) to the mistaken assumption that such errors could be used to measure the spatial variation of track densities. The analysis proposed by JMN 79, employing this assumption, therefore leads to erroneous assessment of the error in an age determination. The basis for the statement is discussed. (U.K.)

  7. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  8. Calibration of a special neutron dosemeter based on solid-state track detectors and fission radiators in various neutron fields

    International Nuclear Information System (INIS)

    Doerschel, B.; Krusche, M.; Schuricht, V.

    1980-01-01

    The calibration of a personnel neutron dosemeter in different neutron fields is described. The badge-like dosemeter contains 5 detectors: polycarbonate foil (10 μm, Makrofol KG), 232 Th, natural uranium, natural uranium with boron, and natural uranium with cadmium. Detector sensitivity and calibration factors have been calculated and measured in radiation fields of 252 Cf fission neutrons, WWR-S reactor neutrons with and without Cd and Fe shielding, 3-MeV (d,t) generator neutrons, and 238 PuBe neutrons. Measurement range and achievable accuracy are discussed from the point of view of applying the dosemeter in routine and emergency uses

  9. Tracking the multi-stage exhumation history of the western Chinese Tianshan by Apatite Fission Track (AFT) dating - Implications for the preservation of epithermal deposits in ancient orogenic belt

    Science.gov (United States)

    Wang, Yannan; Cai, Keda

    2017-04-01

    The western Chinese Tianshan, located in the southern domain of the Central Asian Orogenic Belt (CAOB), was originally constructed by multiple accretion-collision processes in the Paleozoic, and was superimposed by complex intracontinental tectonic evolution in the Mesozoic-Cenozoic. Understanding the timing and mechanism of the latter geological processes is critical to unravel the preservation conditions of the epithermal deposits in the western Chinese Tianshan. This work presents new apatite fission track (AFT) data for three mountain ranges of the western Chinese Tianshan to track their exhumation history. Our AFT data gave a wide range of ages from 76.8 ± 5.5 Ma to 182.3 ± 9.9 Ma, and the mean confined fission track lengths are between 9.8 ± 0.5 μm and 12.3 ± 0.2 μm. The new data, in combination with the thermal history modeling,enable us to attribute the exhumation history to three primary stages, including Early Permian (300-280 Ma), Late Triassic-Early Cretaceous (230-130 Ma), and Late Oligocene-Early Miocene (30-20 Ma). The first stage may be caused by the terrane accretion-collision in the late Paleozoic. The second stage was likely related to the closure of the Mongol-Okhotsk Ocean during the Mesozoic. The last one is regarded as the result of the collision between the Indian Plate and the Eurasia Plate in the Cenozoic. The extraordinary exhumation processes of these three major mountain ranges might have been responsible for sediment supply to the corresponding intra-mountain basins in the western Chinese Tianshan, and the particularly mountain-basin coupling evolution is ascribed to an essential condition for the preservation of epithermal deposits in ancient orogenic belt.

  10. The Carboniferous to Jurassic evolution of the pre-Alpine basement of Crete: Constraints from U-Pb and U-(Th)-Pb dating of orthogneiss, fission-track dating of zircon, structural and petrological data

    Czech Academy of Sciences Publication Activity Database

    Romano, S. S.; Brix, M. R.; Dörr, K.; Fiala, Jiří; Krenn, E.; Zulauf, G.

    2006-01-01

    Roč. 260, - (2006), s. 69-90 ISSN 0375-6440 Institutional research plan: CEZ:AV0Z30130516 Keywords : tectonic-evolution * Carboniferous * Jurassic * uranium-lead-dating * orthogneiss * fission-track-dating * zircon * structural-geology * petrology * metamorphism * high-temperature Subject RIV: DB - Geology ; Mineralogy

  11. Method of photo-etching and photogravure using fission fragment and/or alpha ray etch tracks from toned photographs

    International Nuclear Information System (INIS)

    Thackray, M.

    1973-01-01

    A method is described for reproducing a photographic image on a normally non-photo-receptive surface comprising the steps of: 1) toning the photograph with substances which combine with or replace the silver grains so that the photograph emits either spontaneously or indirectly fission fragments or alpha particles in amounts related to the distribution of the silver grains in the photograph; 2) placing the toned photograph contiguous with the surface on which the image is to be reproduced, for sufficient time for the emissions from the photograph to reproduce the image as a radiation-damage image on the surface, the damage areas having a close positional relationship to the silver grains in the original photograph. (author)

  12. Method of reproducing images using fission fragments and/or alpha ray etch tracks from toned photographs

    International Nuclear Information System (INIS)

    Thackray, M.

    1976-01-01

    A method is described for producing a photographic image on a normally non-photo-receptive surface comprising the steps of 1) toning the photograph with substances which combine with or replace the silver grains so that the photograph emits either spontaneously or indirectly fission fragments or alpha particles in amounts related to the distribution of the silver grains in the photograph, 2) placing the toned photograph contiguous with the surface on which the image is to be reproduced, for sufficient time for the emissions from the photograph to reproduce the image as a radiation-damage image on the surface, the damage areas having a close positional relationship to the silver grains in the original photograph. (author)

  13. Fission-track ages of the Tokai Group and associate formations in the east coast areas of Ise Bay and their significance in geohistory

    International Nuclear Information System (INIS)

    Makinouchi, Takeshi; Danhara, Toru; Isoda, Kunitoshi.

    1983-01-01

    Fission-track ages of volcanic ash layers within the Tokai Group and associate formations in the east coast areas of Ise Bay are obtained by grain-by-grain method with which individual ages for the respective zircon grains are measured. They are as follows; 1) a volcanic ash layer in the Karayama Formation (tentative age: 1.9 +- 0.4 Ma). Among the zircon grains in this layer, essential ones occupy only 1 per cent, and the others are accidental. 2) Ohtani volcanic ash layer (4.3 +- 0.6 Ma). 3) Kosugaya volcanic ash layer (4.0 +- 0.5 Ma). 4) Kaminoma volcanic ash layer (5.3 +- 0.4 Ma). 5) A volcanic ash layer in the Toyoura Formation seems to be older than 10 Ma. 6) Zircon grains in the Kofu volcanic ash layer (Tokai Group) include two types of spontaneous namely track, clear and vague ones. The latter vague tracks are shorter and thiner, and seem to suffer thermal annealing. The ages obtained have clarified the following Points; a) The tentative age, 1.9 Ma, of the ''Karayama'' volcanic ash layer suggests the existence of unknown Plio-Pleistocene sediment in the Nagoya area. b) The sedimentary basin of Lake Tokai was formed in the latest Miocene, about 6.5 Ma. Generation of the basin coincides approximately with the stage of synchronous and abrupt change in sedimentation rate in sedimentary basins on the Pacific side of central and southern Japan. c) The Tokai Group in Chita (Tokoname Group) intercalates the Gilbert/Epoch 5 boundary in the paleomagnetic chronology in the middle horizon of the group. d) Average rate of sedimentation is about 1 m/10 4 yrs in the marginal areas of the basin, and 3-5 m/10 4 yrs in the central areas. (author)

  14. Divergent Small Tim Homologues Are Associated with TbTim17 and Critical for the Biogenesis of TbTim17 Protein Complexes in Trypanosoma brucei

    Science.gov (United States)

    Smith, Joseph T.; Singha, Ujjal K.; Misra, Smita

    2018-01-01

    ABSTRACT The small Tim proteins belong to a group of mitochondrial intermembrane space chaperones that aid in the import of mitochondrial inner membrane proteins with internal targeting signals. Trypanosoma brucei, the protozoan parasite that causes African trypanosomiasis, possesses multiple small Tim proteins that include homologues of T. brucei Tim9 (TbTim9) and Tim10 (TbTim10) and a unique small Tim that shares homology with both Tim8 and Tim13 (TbTim8/13). Here, we found that these three small TbTims are expressed as soluble mitochondrial intermembrane space proteins. Coimmunoprecipitation and mass spectrometry analysis showed that the small TbTims stably associated with each other and with TbTim17, the major component of the mitochondrial inner membrane translocase in T. brucei. Yeast two-hybrid analysis indicated direct interactions among the small TbTims; however, their interaction patterns appeared to be different from those of their counterparts in yeast and humans. Knockdown of the small TbTims reduced cell growth and decreased the steady-state level of TbTim17 and T. brucei ADP/ATP carrier (TbAAC), two polytopic mitochondrial inner membrane proteins. Knockdown of small TbTims also reduced the matured complexes of TbTim17 in mitochondria. Depletion of any of the small TbTims reduced TbTim17 import moderately but greatly hampered the stability of the TbTim17 complexes in T. brucei. Altogether, our results revealed that TbTim9, TbTim10, and TbTim8/13 interact with each other, associate with TbTim17, and play a crucial role in the integrity and maintenance of the levels of TbTim17 complexes. IMPORTANCE Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite’s mitochondrion represents a useful source for potential chemotherapeutic targets. Similarly to yeast and humans, mitochondrial functions depend on the import of proteins that are encoded in the nucleus and made in the cytosol. Even though the machinery involved in this

  15. Phanerozoic brittle tectonics in the South American Continental Platform, Southeast Brazil: new insights from fission track studies on apatite in reactivated fault zones

    International Nuclear Information System (INIS)

    Ribeiro, Luiz Felipe Brandini; Hackspacher, Peter Christian; Saenz, Carlos Alberto Tello; Iunes, Pedro Jose; Hadler Neto, Julio Cesar; Paulo, Sergio R.

    2005-01-01

    Apatite Fission Track Method (FTM) studies were performed on samples coming from two different fault domains in the Precambrian basement of southeast Brazil in order to evaluate subsequent Phanerozoic tectonic movements in that part of the South American Platform. The samples studied were collected along brittle faults in the Mantiqueira mountain range and in the Jundiai upland plain (Braganca Paulista and Extrema), approximately 100 km northeast of Sao Paulo, Brazil. The results of paleostress analysis, as well as the presence of as pseudotachylyte material in the reactivated fault zones, indicates a rapid strain rate and high frictional temperature along these faults. The recognition of deformation related to this brittle tectonic regime is of key importance for the reconstruction of Paleozoic and Mesozoic tectonic evolution of the South American Platform. The causal effects of these tectonic readjustments of cratonic rocks during the breakup of West-Gondwana during the Cretaceous and also in younger geological history, are some of the key parameters for understanding the Phanerozoic evolution of the Mantiqueira mountain range. Our FTM data shows the oldest regional thermal histories are recorded in the Jundiai upland plain beginning in the Upper Triassic (∼190 Ma) at 50 deg C, indicating a rapid cooling that is coincident with the tectonic subsidence of the Parana Basin and, probably, the uplift and preservation of Gondwana surface. These data also show slow linear heating (between 50 to 90 deg C) of the southeastern Brazilian margin up to the Lower Cretaceous (∼120 Ma). This phenomenon could either be related to migration of the Trindade plume, or extensional/compressional movements. At ∼120 Ma a structural inversion occurred and the previous slow linear heating was replaced by slow linear cooling (from 90 to 25 deg C) that has persisted up to the present time. Locally, in the younger fault domain, in the Mantiqueira Range near Extrema, fission tracks

  16. Why tracks

    International Nuclear Information System (INIS)

    Burchart, J.; Kral, J.

    1979-01-01

    A comparison is made of two methods of determining the age of rocks, ie., the krypton-argon method and the fission tracks method. The former method is more accurate but is dependent on the temperature and on the grain size of the investigated rocks (apatites, biotites, muscovites). As for the method of fission tracks, the determination is not dependent on grain size. This method allows dating and the determination of uranium concentration and distribution in rocks. (H.S.)

  17. The thermal evolution and timing of hydrocarbon generation in the Maritimes Basin of eastern Canada: evidence from apatite fission track data

    International Nuclear Information System (INIS)

    Grist, A.M.; Zentilli, M.

    1995-01-01

    Sandstone drill core and/or cuttings from six wells in the Gulf of St. Lawrence and cabot Strait have been analyzed using the apatite fission track (AFT) method. Measured AFT ages for the late Paleozoic sandstones range from 26 ±7 to 184 ±28 Ma (2-σ errors). The AFT data indicate that most Maritimes Basin strata were heated to temperatures in excess of 100-150 o C very soon after their deposition. The strata also attained significant vitrinite reflectance (R 0 ) levels (i.e., reaching the oil window) early in the burial history. These findings imply the generation of hydrocarbons and coalbed methane in the early basin history (pre-250 Ma). In the Maritimes Basin AFT and R 0 data provide complementary information about the integrated thermal history, including maximum burial temperatures (from R 0 data), and information on the subsequent cooling history from AFT analysis. The present study also supports the proposal made previously by others that substantial erosion of the Eastern Canadian margin (up to 4 km) has occurred since the Permian and extends the AFT evidence for this erosional event to include the southern Gulf of St. Lawrence area. Thermal models of the AFT data demonstrate that they are consistent with a history of exhumation of basin strata since late Permian time. The model-predicted AFT age and track length histograms closely correspond to the measured AFT parameters. AFT analysis also indicates present-day geothermal gradients of less than 40 o C/km. (author). 42 refs.,3 tabs., 7 figs

  18. Nuclear fission

    International Nuclear Information System (INIS)

    Kodama, T.

    1981-01-01

    The nuclear fission process is pedagogically reviewed from a macroscopic-microscopic point of view. The Droplet model is considered. The fission dynamics is discussed utilizing path integrals and semiclassical methods. (L.C.) [pt

  19. Fission track analysis and evolution of mesozoic-paleozoic hydrocarbon resource-rocks headed in Northern Jiangsu-South Yellow sea basin

    International Nuclear Information System (INIS)

    Xu Hong; Cai Qianzhong; Sun Heqing; Guo Zhenxuan; Yan Guijing; Dai Jing; Liu Dongying

    2008-01-01

    Fission track data of different geologic epoches from Binhai salient, Yancheng sag, Haian sag, Baiju sag, Gaoyou sag, Hongze sag and Jinhu sag of northern Jiangsu basin and seismic data from Laoshan uplift in South Yellow Sea basin and evolution of Paleozoic hydrocarbon resource-rocks headed in the Northern Jiangsu-South Yellow Sea basin were studied. Results indicate that Binhai salient uplifted in 38-15 Ma, forming 'structure uplifting model', Paleozoic hydrocarbon resource-rocks have the appearance of 'different layers but identical mature, different layers but identical temperature' with Laoshan uplift. All sags have the characters of 'long time heating model', and sedimentations in Cenozoic were exploited by 2 km. Mesozoic-Paleozoic hydrocarbon resource- rocks of Laoshan uplift get ahead of 10 km. Structure evolution was compared with Binhai salient. According to the modeling results of secondary hydrocarbon generation, Mesozoic-Paleozoic hydrocarbon resource-rocks of Laoshan uplift have the good reservoir potentiality and probably become an important new window for sea oil and gas exploration. (authors)

  20. Intercomparison study of inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis of μBq quantities of 239Pu in synthetic urine

    International Nuclear Information System (INIS)

    Inn, K.G.W.; McCurdy, D.; Kuruvilla, L.; Barss, N.M.; Bell III, R.T.; Pietrzak, R.; Kaplan, E.; Inkret, W.; Efurd, W.; Rokop, D.; Lewis, D.; Gautier, P.

    2001-01-01

    Even today, some Marshall Islanders are looking forward to permanently resettling their islands after five decades. The U.S. Department of Energy and the resettled residents require reasonable but cost-prudent assurance that the doses to resident from residual 239 Pu will not exceed recognized international standards or recommendations, as estimated from the excretion of 239 Pu in urine. The goal of this study was to evaluate the bias, uncertainty and sensitivity of analytical techniques that measure 3-56 μBq 239 Pu in synthetic urine. The analytical techniques studied in this work included inductively coupled plasma mass spectrometry, thermal ionization mass spectrometry and fission track analysis. The results of the intercomparison demonstrated that all three techniques were capable of marking the measurements, although not with equal degree of bias and uncertainty. The estimated minimum detectable activity was 1 μBq of 239 Pu per synthetic urine sample. This exercise is also the first effort to certify test materials of plutonium in the nBqxg -1 range. (author)

  1. Onshore and offshore apatite fission-track dating from the southern Gulf of California: Insights into the time-space evolution of the rifting

    Science.gov (United States)

    Balestrieri, Maria Laura; Ferrari, Luca; Bonini, Marco; Duque-Trujillo, Jose; Cerca, Mariano; Moratti, Giovanna; Corti, Giacomo

    2017-11-01

    We present the results of a apatite fission-track (AFT) study on intrusive rocks in the southern Gulf of California, sampled along the eastern margin of Baja California Sur (western rift margin), as well as from islands and submerged rifted blocks within the Gulf of California, and from the conjugate Mexican margin (Nayarit state). For most of the samples U-Pb zircon and 40Ar-39Ar mineral ages were already available (Duque-Trujillo et al., 2015). Coupled with the new AFT data these ages provide a more complete information on cooling after emplacement. Our samples span a wide range of ages between 5.5 ± 1.1 and 73.7 ± 5.8 Ma, and show a general spatial distribution, with late Miocene AFT ages (about 6 Ma) aligned roughly NW-SE along a narrow offshore belt, parallel to Baja California Peninsula, separating older ages on both sides. This pattern suggests that in Late Miocene, deformation due to plate transtension focused at the eastern rheological boundary of the Baja California block. Some Early Miocene AFT ages onshore Baja California could be related to plutons emplaced at shallow depths and thermal resetting associated with the onset of volcanism at 19 Ma in this part of the Peninsula. On the other hand, an early extensional event similar to that documented in the eastern Gulf cannot be ruled out in the westernmost Baja California.

  2. Denudation and uplift of the Mawson Escarpment (eastern Lambert Graben, Antarctica) as indicated by apatite fission track data and geomorphological observation

    Science.gov (United States)

    Lisker, F.; Gibson, H.; Wilson, C.J.; Läufer, A.

    2007-01-01

    Analysis of three vertical profiles from the southern Mawson Escarpment (Lambert Graben) reveals apatite fission track (AFT) ages ranging from 102±20 to 287±23 Ma and mean lengths of 12.2 to 13.0 μm. Quantitative thermal histories derived from these data consistently indicate onset of slow cooling below 110°C began sometime prior to 300 Ma, and a second stage of rapid cooling from paleotemperatures up to ≤100°C to surface temperatures occurred in the Late Cretaceous – Paleocene. The first cooling phase refers to Carboniferous – Jurassic basement denudation up to 5 km associated with the initial rifting of the Lambert Graben. The presence of the ancient East Antarctic Erosion Surface and rapid Late Cretaceous – Paleocene cooling indicate a second denudational episode during which up to 4.5 km of sedimentary cover rocks were removed, and that is likely linked to the Cretaceous Gondwana breakup between Antarctica and India and subsequent passive continental margin formation.

  3. Argon and fission track dating of Alpine metamorphism and basement exhumation in the Sopron Mts. (Eastern Alps, Hungary): thermochronology or mineral growth?

    International Nuclear Information System (INIS)

    Balogh, K.; Dunkl, I.

    2005-01-01

    The crystalline basement rocks of the Sopron Mountains are the easternmost and most isolated outcrops of the Austroalpine basement of the Eastern Alps. Ar/Ar and K/Ar dating of phengitic mica indicates that the Eoalpine high-pressure metamorphism of the area occurred between 76 and 71 Ma. Short-lived metamorphism is characterized by fluid-poor conditions. Fluid circulation was mostly restricted to shear zones, thus the degree of Alpine overprint has an extreme spatial variation. In several metamorphic slices Variscan mineral assemblages have been preserved and biotite yielded Variscan and Permo-Triassic Ar ages. Different mineral and isotope thermometers (literature data) yielded temperatures of 500-600 o C for the peak of Alpine metamorphism in the Sopron Mountains, but muscovite and biotite do not show complete argon resetting. Thus, we consider this crystalline area as a well constrained natural test site, which either indicates considerably high closure temperatures (around 550 o C) for Ar in muscovite and biotite in a dry metamorphic environment, or which is suitable for testing the widely applied methods of temperature estimations under disequilibrium conditions. Apatite fission track results and their thermal modeling, together with structural, mineralogical and sedimentological observations, allows the identification of a post-metamorphic, Eocene hydrothermal event and Late Miocene-Pliocene sediment burial of the crystalline rocks of the Sopron Mountains. (author)

  4. Thermo chronology by fission tracks of the conjugated rift margins of the Liguro-Provencal basin: Corsica and the Maures-Tanneron Massif

    International Nuclear Information System (INIS)

    Jakni, B.

    2000-01-01

    We have employed apatite fission-track (AFT) thermo-chronology on granitic and metamorphic samples taken from Corsican and Maures-Tanneron basement rocks as well as alpine 'schistes lustres' units in Corsica, in order to constrain the cooling histories and the tectonic evolution of the Liguro-Provencal basin margins. The AFT data indicate that: -) the Tanneron massif (AFT ages 145- 150 My) appears to record the earliest cooling history, reflecting thermal relaxation related to opening of the Tethys; -) the Maures basement (AFT ages 20-25 My) clearly records a thermo- tectonic evolution associated with Liguro-Provencal rifting; -) the island of Corsica, which was the main focus of this work and which shows a complex geomorphology and a poly-phased tectonic evolution. shows a remarkable zoning in the distribution of AFT ages, reflecting the signature of at least two post-Oligocene thermal events. Those events are related to the opening of Liguro-Provencal basin (20-25 My) in the west, and exhumation of the Hercynian basement related to Tyrrhenian extension (12- 16 My) in the east. In the east-Tenda shear zone, which forms the contact between the alpine units and Hercynian basement in northern Corsica, our results indicate that the Tenda Massif was being exhumed from about 21 Ma onwards. (author)

  5. Apatite fission track and (U-Th)/He dating of teschenite intrusions gives time constraints on accretionary processes and development of planation surfaces in the Outer Western Carpathians

    Energy Technology Data Exchange (ETDEWEB)

    Danisik, Martin; Frisch, Wolfgang [Tuebingen Univ. (Germany). Inst. of Geosciences; Panek, Tomas [Ostrava Univ. (Czech Republic). Dept. of Physical Geography and Geoecology; Matysek, Dalibor [Technical Univ. of Ostrava (Czech Republic). Dept. of Geological Engineering; Dunkl, Istvan [Geoscience Center Goettingen (Germany). Sedimentology and Environmental Geology

    2008-09-15

    The age of planation surfaces in the Podbeskydska pahorkatina Upland in the Outer Western Carpathians (OWC, Czech Republic) is constrained by low-temperature thermochronological dating methods for the first time. Our apatite fission track and apatite (U-Th)/He data measured on teschenite intrusions show that planation surfaces in the study area formed in post-Pannonian time (>7.1 Ma) and are therefore younger than traditionally believed. This contradicts the classical concepts, which stipulate that a large regional planation surface of Pannonian age (the so-called ''midmountain level'') developed in the whole Western Carpathians. Geodynamic implications of our data are the following: (i) the investigated Tesin and Godula nappes of the OWC were buried and thermally overprinted in the accretionary wedge in different ways, and consequently experienced different cooling histories. This indicates a dynamic basin setting with an active accretionary process in a subduction zone; (ii) accretionary processes in the OWC were active already during Late Eocene times. (orig.)

  6. Thermal modeling and geomorphology of the south border of the Sao Francisco Craton: thermochronology by fission tracks in apatites;Modelagem termica e geomorfologia da borda sul do Craton do Sao Francisco: termocronologia por tracos de fissao em apatita

    Energy Technology Data Exchange (ETDEWEB)

    Hackspacher, Peter Christian [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas; Godoy, Daniel Francoso de; Franco, Ana Olivia Barufi [UNESP, Rio Claro, SP (Brazil). Pos-Graduacao em Geologia Regional; Ribeiro, Luiz Felipe Brandini [NUCLEARGEO, Rio Claro, SP (Brazil); Hadler Neto, Julio Cesar [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin

    2007-12-15

    Recent developments in Fission Track thermochronology associated to mesozoic-cenozoic erosion and tectonic presented trough thematic maps (isotemperature), permit to model the landscape evolution in the southern border of the Sao Francisco craton, southeastern Brazil. Paleotemperature, obtained by fission track analysis in apatite, is closely related to geomorphologic interpretations. The area suffered a complex imprint of endogenous and exogenous processes resulting diversified and differentiated relieves. The landscape is strongly controlled by exhumation between Jurassic and Lower Cretaceous, uplift with tectonic denudation related to crustal heating at the Upper Cretaceous and reactivation of faults until the Miocene. This scenario is a result of reactivations of different brittle structures that accommodate the deformation in the southern border of the Sao Francisco craton. The landscape reflects denudations of up to 3 km with preserved remains of erosive surfaces in the topographical tops and chronocorrelates deposits in the basins of the region. (author)

  7. Mast cell activation is enhanced by Tim1:Tim4 interaction but not by Tim-1 antibodies [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Binh Phong

    2016-07-01

    Full Text Available Polymorphisms in the T cell (or transmembrane immunoglobulin and mucin domain 1 (TIM-1 gene, particularly in the mucin domain, have been associated with atopy and allergic diseases in mice and human. Genetic- and antibody-mediated studies revealed that Tim-1 functions as a positive regulator of Th2 responses, while certain antibodies to Tim-1 can exacerbate or reduce allergic lung inflammation. Tim-1 can also positively regulate the function of B cells, NKT cells, dendritic cells and mast cells. However, the precise molecular mechanisms by which Tim-1 modulates immune cell function are currently unknown. In this study, we have focused on defining Tim-1-mediated signaling pathways that enhance mast cell activation through the high affinity IgE receptor (FceRI. Using a Tim-1 mouse model lacking the mucin domain (Tim-1Dmucin, we show for the first time that the polymorphic Tim-1 mucin region is dispensable for normal mast cell activation. We further show that Tim-4 cross-linking of Tim-1 enhances select signaling pathways downstream of FceRI in mast cells, including mTOR-dependent signaling, leading to increased cytokine production but without affecting degranulation.

  8. Cooling, exhumation, and deformation in the Hindu Kush, NW Pakistan: New constraints from preliminary 40Ar/39Ar and fission track analyses

    Science.gov (United States)

    Faisal, Shah; Larson, Kyle P.; Camacho, Alfredo; Coutand, Isabelle

    2018-06-01

    Asian crust in the Hindu Kush region in northern Pakistan records a protracted history of rifting, subduction and collision not commonly preserved within the Himalaya. Because of this, it is key to understanding the development of the southern Eurasian margin both prior to and after collision with India. New mica 40Ar/39Ar and apatite fission track geochronologic data from this region provide constraints on the kinematics of the Hindu Kush. 40Ar/39Ar muscovite and biotite ages from the late Cambrian Kafiristan pluton are 379.7 ± 1.7 Ma and 47.2 ± 0.3 Ma, respectively. The muscovite age may record cooling or partial resetting, while the biotite age is interpreted to record a thermal disruption associated with the early stages of continental collision in the Himalayan system. A 111.0 ± 0.6 Ma muscovite age from the northern part of the Tirich Mir pluton (∼123 Ma old; U-Pb) is interpreted to indicate a recrystallization event ∼12 Myrs after its intrusion. In addition, a younger muscovite age of 47.5 ± 0.2 Ma was derived from the opposite side of the same pluton in the immediate hanging wall of the Tirich Mir fault. This Eocene age is interpreted to represent the time of recrystallization during fault (re)activation in the early stages of India-Asia continent-continent collision. 40Ar/39Ar biotite analysis from the Buni-Zom pluton yields an age of 61.6 ± 1.1 Ma and is interpreted to reflect cooling at mid-upper crustal levels subsequent to the pluton's emplacement in the middle Cretaceous. Finally, 17.1-21.3 Ma 40Ar/39Ar ages from the Garam Chasma pluton and surrounding metapelites indicate cooling immediately following crystallization of the leucogranite body in the earliest Miocene/latest Oligocene. The younger cooling history is resolved by fission track dating of apatite (AFT). In the vicinity of the bounding Tirich Mir fault, the Tirich Mir pluton yields an AFT age of 1.4 ± 0.3 Ma, which is consistent with active exhumation associated with the surface

  9. The Thermal Evolution of the Southeast Baffin Island Continental Margin: An Integrated Apatite Fission Track and Apatite (U-Th)/He Study

    Science.gov (United States)

    Jess, S.; Stephenson, R.; Brown, R. W.

    2017-12-01

    The elevated continental margins of the North Atlantic continue to be a focus of considerable geological and geomorphological debate, as the timing of major tectonic events and the age of topographic relief remain controversial. The West Greenland margin, on the eastern flank of Baffin Bay, is believed by some authors to have experienced tectonic rejuvenation and uplift during the Neogene. However, the opposing flank, Baffin Island, is considered to have experienced a protracted erosional regime with little tectonic activity since the Cretaceous. This work examines the thermal evolution of the Cumberland Peninsula, SE Baffin Island, using published apatite fission track (AFT) data with the addition of 103 apatite (U-Th)/He (AHe) ages. This expansion of available thermochronological data introduces a higher resolution of thermal modelling, whilst the application of the newly developed `Broken Crystals' technique provides a greater number of thermal constraints for an area dominated by AHe age dispersion. Results of joint thermal modelling of the AFT and AHe data exhibit two significant periods of cooling across the Cumberland Peninsula: Devonian/Carboniferous to the Triassic and Late Cretaceous to present. The earliest phase of cooling is interpreted as the result of major fluvial systems present throughout the Paleozoic that flowed across the Canadian Shield to basins in the north and south. The later stage of cooling is believed to result from rift controlled fluvial systems that flowed into Baffin Bay during the Mesozoic and Cenozoic during the early stages and culmination of rifting along the Labrador-Baffin margins. Glaciation in the Late Cenozoic has likely overprinted these later river systems creating a complex fjordal distribution that has shaped the modern elevated topography. This work demonstrates how surface processes, and not tectonism, can explain the formation of elevated continental margins and that recent methodological developments in the field of

  10. Post-Triassic thermal history of the Tazhong Uplift Zone in the Tarim Basin, Northwest China: Evidence from apatite fission-track thermochronology

    Directory of Open Access Journals (Sweden)

    Caifu Xiang

    2013-11-01

    Full Text Available The Tarim Basin is a representative example of the basins developed in the northwest China that are characterized by multiple stages of heating and cooling. In order to better understand its complex thermal history, apatite fission track (AFT thermochronology was applied to borehole samples from the Tazhong Uplift Zone (TUZ. Twelve sedimentary samples of Silurian to Triassic depositional ages were analyzed from depths coinciding with the apatite partial annealing zone (∼60–120 °C. The AFT ages, ranging from 132 ± 7 Ma (from a Triassic sample to 25 ± 2 Ma (from a Carboniferous sample, are clearly younger than their depositional ages and demonstrate a total resetting of the AFT thermometer after deposition. The AFT ages vary among different tectonic belts and decrease from the No. Ten Faulted Zone (133–105 Ma in the northwest, the Central Horst Zone in the middle (108–37 Ma, to the East Buried Hill Zone in the south (51–25 Ma. Given the low magnitude of post-Triassic burial heating evidenced by low vitrinite reflectance values (Ro < 0.7%, the total resetting of the AFT system is speculated to result from the hot fluid flow along the faults. Thermal effects along the faults are well documented by younger AFT ages and unimodal single grain age distributions in the vicinity of the faults. Permian–early Triassic basaltic volcanism may be responsible for the early Triassic total annealing of those samples lacking connectivity with the fault. The above arguments are supported by thermal modeling results.

  11. Apatite fission-track evidence for regional exhumation in the subtropical Eocene, block faulting, and localized fluid flow in east-central Alaska

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Bacon, Charles R.; O'Sullivan, Paul B.; Day, Warren C.

    2016-01-01

    The origin and antiquity of the subdued topography of the Yukon–Tanana Upland (YTU), the physiographic province between the Denali and Tintina faults, are unresolved questions in the geologic history of interior Alaska and adjacent Yukon. We present apatite fission-track (AFT) results for 33 samples from the 2300 km2 western Fortymile district in the YTU in Alaska and propose an exhumation model that is consistent with preservation of volcanic rocks in valleys that requires base level stability of several drainages since latest Cretaceous–Paleocene time. AFT thermochronology indicates widespread cooling below ∼110 °C at ∼56–47 Ma (early Eocene) and ∼44–36 Ma (middle Eocene). Samples with ∼33–27, ∼19, and ∼10 Ma AFT ages, obtained near a major northeast-trending fault zone, apparently reflect hydrothermal fluid flow. Uplift and erosion following ∼107 Ma magmatism exposed plutonic rocks to different extents in various crustal blocks by latest Cretaceous time. We interpret the Eocene AFT ages to suggest that higher elevations were eroded during the Paleogene subtropical climate of the subarctic, while base level remained essentially stable. Tertiary basins outboard of the YTU contain sediment that may account for the required >2 km of removed overburden that was not carried to the sea by the ancestral Yukon River system. We consider a climate driven explanation for the Eocene AFT ages to be most consistent with geologic constraints in concert with block faulting related to translation on the Denali and Tintina faults resulting from oblique subduction along the southern margin of Alaska.

  12. Apatite fission-track thermochronometric constraints on the exhumation and evolution of the southeastern Indian (Tamil Nadu) passive margin and the role of structural inheritance

    Science.gov (United States)

    De Grave, Johan; Glorie, Stijn; Singh, Tejpal; Van Ranst, Gerben; Nachtergaele, Simon

    2017-04-01

    After rifting from Gondwana in the Late Jurassic - Early Cretaceous, and subsequent opening of the Indian Ocean basin, the continental margins of India developed into typical passive margins. Extensional tectonic forces and thermal subsidence gave rise to the formation of both on-shore and off-shore basins along the southeastern passive margin of the Indian continent, along the Tamil Nadu coast. There, basins such as the Cauvery and Krishna-Godavari basin, accumulated Meso- and Cenozoic (Early Cretaceous to recent) detrital sediments coming off the rifted blocks and the Tamil Nadu hinterland. In places, deep rift basins have accumulated up to over 3000 m of sediments. The continental basement of Tamil Nadu is chiefly composed of metamorphic rocks of the Archean to Palaeoproterozoic Eastern Dharwar Craton and the coeval Southern Granulite Terrane (e.g. Peucat et al., 2013). Several crustal scale shear zones crosscut this assemblage and at least some are considered to represent Gondwanan sutures (Santosh et al., 2012). Smaller, younger granitoid plutons intrude the basement at several locations and most of these are of Late Neoproterozoic age (Glorie et al., 2014). In this work metamorphic basements rocks and the younger granitoids were sampled for a apatite fission-track (AFT) thermochronometric study. A North-South profile from Chennai to Thanjavur mainly transects the Salem block of the Southern Granulite Terrane, and crosscuts several crustal scale shear zones, such as the Cauvery, Salem-Attur and Gangavalli shear zones. Apatites from over 30 samples were used in this study. AFT ages all range between about 190 and 120 Ma (Jurassic - Early Cretaceous). These mainly represent the slow, shallow exhumation of the basement during the rift and early drift phase of the Indian plate from Gondwana. AFT mean track lengths vary between 11 and 13 µm and are typical of slowly exhumed basement. Thermal history modelling (using the QTQt software by Gallagher, 2012) confirms

  13. Heavy metal contamination in TIMS Branch sediments

    International Nuclear Information System (INIS)

    Pickett, J.B.

    1990-01-01

    The objective of this memorandum is to summarize results of previous sediment studies on Tims Branch and Steed's Pond conducted by Health Protection (HP) and by the Savannah River Laboratory (SRL) in conjunction with Reactor Materials Engineering ampersand Technology (RMET). The results for other heavy metals, such as lead, nickel, copper, mercury, chromium, cadmium, zinc, and thorium are also summarized

  14. TIM-1 Promotes Hepatitis C Virus Cell Attachment and Infection.

    Science.gov (United States)

    Wang, Jing; Qiao, Luhua; Hou, Zhouhua; Luo, Guangxiang

    2017-01-15

    Human TIM and TAM family proteins were recently found to serve as phosphatidylserine (PS) receptors which promote infections by many different viruses, including dengue virus, West Nile virus, Ebola virus, Marburg virus, and Zika virus. In the present study, we provide substantial evidence demonstrating that TIM-1 is important for efficient infection by hepatitis C virus (HCV). The knockdown of TIM-1 expression significantly reduced HCV infection but not HCV RNA replication. Likewise, TIM-1 knockout in Huh-7.5 cells remarkably lowered HCV cell attachment and subsequent HCV infection. More significantly, the impairment of HCV infection in the TIM-1 knockout cells could be restored completely by ectopic expression of TIM-1 but not TIM-3 or TIM-4. Additionally, HCV infection and cell attachment were inhibited by PS but not by phosphatidylcholine (PC), demonstrating that TIM-1-mediated enhancement of HCV infection is PS dependent. The exposure of PS on the HCV envelope was confirmed by immunoprecipitation of HCV particles with a PS-specific monoclonal antibody. Collectively, these findings demonstrate that TIM-1 promotes HCV infection by serving as an attachment receptor for binding to PS exposed on the HCV envelope. TIM family proteins were recently found to enhance infections by many different viruses, including several members of the Flaviviridae family. However, their importance in HCV infection has not previously been examined experimentally. The TIM family proteins include three members in humans: TIM-1, TIM-3, and TIM-4. The findings derived from our studies demonstrate that TIM-1, but not TIM-3 or TIM-4, promotes HCV infection by functioning as an HCV attachment factor. Knockout of the TIM-1 gene resulted in a remarkable reduction of HCV cell attachment and infection. PS-containing liposomes blocked HCV cell attachment and subsequent HCV infection. HCV particles could also be precipitated with a PS-specific monoclonal antibody. These findings suggest that TIM-1

  15. Deciphering Past and Present Tectonics of the Rio Grande Rift in New Mexico Utilizing Apatite Fission Track Thermochronology, Geochronology, Quaternary Faulting, and Cross-Section Restoration

    Science.gov (United States)

    Ricketts, J. W.; Karlstrom, K. E.; Kelley, S. A.; Priewisch, A.; Crossey, L. J.; Asmerom, Y.; Polyak, V.; Selmi, M.

    2011-12-01

    The Rio Grande rift provides an excellent laboratory for understanding styles and processes of extensional tectonics, and their driving forces. We apply apatite fission track (AFT) thermochronology, geochronology, fracture analysis, and cross-section restoration to decipher past and present tectonics of the Rio Grande rift. AFT data has been compiled from rift flank uplifts along the Rio Grande rift in an attempt to recognize long wavelength spatial and temporal patterns. AFT ages record time of cooling of rocks below ~110°C and, when cooling is due to exhumation, age elevation traverses can record upward advection of rocks through paleo 110°C isotherms. The relatively passive sides of half-grabens (e.g. Manzanos and Santa Fe Range) preserve Laramide AFT ages ranging from 45-70 Ma, indicating they were cooled during the Laramide Orogeny and have remained cooler than 110°C since then. Rift flanks on the tectonically active sides of half-grabens, (e.g. Sierra Ladrones, Sandias, Taos Range, and Sierra Blanca) have AFT ages that range from 35 Ma to history and its mechanisms. AFT data at Ladron Peak, an active rift flank along the western margin of the Rio Grande rift in central New Mexico, indicates that it was rapidly unroofed between 20-10 Ma. Preliminary apatite helium data gives a similar age vs. elevation trend, but apatites have highly radiogenically damaged lattices and hence have corrected closure temperatures tens of degrees higher than AFT ages. The style of faulting at Ladron Peak is unusual because it is bounded by the anomalously low-angle (~15°) Jeter fault. In order to understand the evolution of faulting in this region, a balanced cross-section was constructed and restored to its pre-rift geometry. Our working hypothesis is that the low angle of the Jeter fault is most adequately explained by a rolling hinge model, where isostatic uplift causes progressive rotation of an initially steep (~60°) normal fault to shallower dips. Thirty km north of

  16. Detrital fission-track-compositional signature of an orogenic chain-hinterland basin system: The case of the late Neogene Quaternary Valdelsa basin (Northern Apennines, Italy)

    Science.gov (United States)

    Balestrieri, M. L.; Benvenuti, M.; Tangocci, F.

    2013-05-01

    Detrital thermochronological data collected in syn-tectonic basin deposits are a promising tool for deciphering time and processes of the evolution of orogenic belts. Our study deals with the Valdelsa basin, one of the wider basins of central Tuscany, Italy. The Valdelsa basin is located at the rear of the Northern Apennines, a collisional orogen whose late Neogene Quaternary development is alternatively attributed to extensional and compressional regimes. These contrasting interpretations mostly rely on different reconstructions of the tectono-sedimentary evolution of several basins formed at the rear of the chain since the late Tortonian. Here, we explore the detrital thermochronological-compositional signature of tectonic and surface processes during the Valdelsa basin development. For this aim, detrital apatite fission-track analysis of 21 sand samples from the latest Messinian Gelasian fluvial to shallow marine basin deposits, has been accompanied by a clast composition analysis of 7 representative outcrops of the conglomerate facies. The grain-age distributions of the sediment samples are generally characterized by two distinct components, one younger peak (P1) varying between 5.5 ± 2.8 and 9.5 ± 1.0 Ma and one older peak (P2) varying from 15.0 ± 8.0 to 41.0 ± 10 Ma. By comparison with some bedrock ages obtained from the E-NE basin shoulder, we attributed the P2 peak to the Ligurian Units and the P1 peak to the Macigno Formation (Tuscan Units). These units are arranged one upon the other in the complex nappe pile forming the Northern Apennines orogen. While the gravel composition indicates a predominant feeding from the Ligurian units all along the sedimentary succession with a subordinate occurrence of Macigno pebbles slightly increasing upsection, the P1 peak is present even in the oldest collected sandy sediments. The early P1 occurrence reveals that the Macigno was exposed in the E-NE basin shoulder since at least the latest Messinian-early Zanclean

  17. Burial and exhumation history of southern Sweden estimated from apatite fission-track data, stratigraphic landform analysis and the geological record

    Science.gov (United States)

    Japsen, Peter; Green, Paul F.; Lidmar-Bergström, Karna; Bonow, Johan M.; Erlström, Mikael

    2014-05-01

    We present new apatite fission-track analysis (AFTA) data from 87 samples of basement and sediment from southern Sweden, including samples from a 1.7 km deep borehole. The new AFTA data allow us to confirm the development of the South Swedish Dome as inferred from stratigraphic landform analysis (e.g. Lidmar-Bergström et al., 2013) and also to define the timing and magnitude of the events of burial and exhumation that shaped this prominent feature. Southern Sweden underwent a complex Palaeozoic - early Triassic history of burial and exhumation, but after a mid-Triassic event of uplift and exhumation, rocks on the Sub-Cambrian Peneplain cooled from palaeotemperatures ≥100°C. This event, that also affected southern Norway, West and East Greenland, marks an important phase in the breakup of Pangea. A second, regional phase of cooling and exhumation affected the area in the mid-Jurassic and eventually lead to stripping of the basement along the western and southern flanks of the South Swedish Dome prior to Late Cretaceous subsidence and burial and thus to formation of the sub-Cretaceous hilly relief. This event affected much of NW Europe as well as West and East Greenland, and it is coeval with the initial opening of the central Atlantic. A third, regional phase of cooling and exhumation from palaeotemperatures of 50-60°C took place in the Miocene and lead to the formation of the South Småland Peneplain. This phase affected southern Scandinavia but has no counterpart in Greenland. A final uplift phase that raised the South Småland Peneplain to its present elevation and lead to re-exposure of sub-Cretaceous hilly relief is not resolved in the AFTA data. The results underline the importance of epeirogenic movements (both uplift and subsidence) in regions that are often considered as stable cratons (cf. Green et al., 2013). Green, P.F., Lidmar-Bergström, K., Japsen, P., Bonow, J.M., Chalmers, J.A., 2013. Stratigraphic landscape analysis, thermochronology and the

  18. Dynamic of an intra-continental orogenic prism: thermo-chronologic (apatite fission tracks) and tectonic evolution of the axial zone and the piedmont of the west-central Pyrenees

    International Nuclear Information System (INIS)

    Meresse, F.

    2013-02-01

    This work illustrates the application of thermo chronology to the study of the following geologic issue: the tectonic evolution of the Pyrenean oncologic prism. Thermo-chronology gives information on the vertical movements at the scale of geological eras. Thermo-chronology is based on the following principle: the decay of a nucleus gives birth to a daughter nucleus. Above a specific temperature named closure temperature, the daughter element can diffuse outside the system while below the closure temperature, diffusion is not possible. Consequently thermo-chronology can be considered to date the moment when a mineral goes below a a specific closure temperature. Minerals have different closure temperatures and so by using a suite of thermo-chronometers on a single sample, its cooling path through the crust can be reconstructed. This work focuses on apatite fission track (AFT)analysis which is a low temperature thermo-chronometer. In apatites the temperature range between 60 and 120 Celsius degrees corresponds to the partial annealing zone. The spontaneous fission of one U 238 nucleus entails the formation of one fission track. The determination of the initial quantity of U 238 is based on the natural steady ratio U 238 /U 235 which equals 137.88. The initial quantity of U 235 is determined through the neutron irradiation of the sample. The knowledge of the initial quantity of U 238 and the number of tracks in the sample allows the dating of the sample. In this work we combine AFT thermo- chronology with a detailed structural analysis to describe vertical movements related to the thrusting system evolution, and to determine the influence of the latter on the sedimentation/burial/exhumation cycle of the syn-orogenic deposits of the southern fore-land basin

  19. Ternary fission

    International Nuclear Information System (INIS)

    Wagemans, C.

    1991-01-01

    Since its discovery in 1946, light (charged) particle accompanied fission (ternary fission) has been extensively studied, for spontaneous as well as for induced fission reactions. The reason for this interest was twofold: the ternary particles being emitted in space and time close to the scission point were expected to supply information on the scission point configuration and the ternary fission process was an important source of helium, tritium, and hydrogen production in nuclear reactors, for which data were requested by the nuclear industry. Significant experimental progress has been realized with the advent of high-resolution detectors, powerful multiparameter data acquisition systems, and intense neutron and photon beams. As far as theory is concerned, the trajectory calculations (in which scission point parameters are deduced from the experimental observations) have been very much improved. An attempt was made to explain ternary particle emission in terms of a Plateau-Rayleigh hydrodynamical instability of a relatively long cylindrical neck or cylindrical nucleus. New results have also been obtained on the so-called open-quotes trueclose quotes ternary fission (fission in three about-equal fragments). The spontaneous emission of charged particles has also clearly been demonstrated in recent years. This chapter discusses the main characteristics of ternary fission, theoretical models, light particle emission probabilities, the dependence of the emission probabilities on experimental variables, light particle energy distributions, light particle angular distributions, correlations between light particle accompanied fission observables, open-quotes trueclose quotes ternary fission, and spontaneous emission of heavy ions. 143 refs., 18 figs., 8 tabs

  20. Thorium-uranium fission radiography

    Science.gov (United States)

    Haines, E. L.; Weiss, J. R.; Burnett, D. S.; Woolum, D. S.

    1976-01-01

    Results are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.

  1. Preliminary study of geotectonic evolution of the southern region of Sao Francisco (MG, Brazil) craton: an interpretation based on Rb-Sr, K-Ar, Pb-Pb and fission track data

    International Nuclear Information System (INIS)

    Teixeira, W.; Fonseca, A.C.; Poupeau, G.; Padilha, A.V.; Zapparolli, L.H.; Kawashita, K.; Khoury, M.C.

    1985-01-01

    The results obtained from isotopic dating techniques (Rb-Sr, K-Ar, Pb-Pb and fission tracks) applied to samples from the southern region of Sao Francisco craton (Mg, Brazil) are discussed. Rb-Sr and Pb-Pb ages, in total rock, allowed the determination of crust enlargement, with eventual modifications of the pre-existing crust, during the Late Archean period (3000 to 2600 million years) and the Inferior Proterozoic period (2400 to 2100 m.y.). Three main cooling periods of time were determined by K-Ar dating of mica, amphiboles and total rock at the craton border: 2200 to 1700 m.y., 1300 to 1100 m.y. and 900 to 400 m.y. related, respectively, to superposition of three cycles: Transamazonico, Uruacuano and Brasiliano. Cooling below 110 0 C, detected by the fission track method applied to apatites, pointed out an age of 850 m.y. at the internal parts and 550 m.y. at the craton periphery, thus showing a progressive action of Brazilian marginal movable zones in the studied region. The application of these two techniques together enabled the evaluation of the rocks cooling shape. Cooling of these samples was complex between 2700 and 2200 m.y. and slow from 2000 m.y. onwards. The integrated treatment of data from the various dating techniques is of great importance to know the geotectonic evolution of ancient polycyclic sites. (C.L.B.) [pt

  2. Mid-miocene cooling in the northern Qilian Shan, northeastern margin of the Tibetan plateau, revealed by apatite fission-track and VR analysis

    International Nuclear Information System (INIS)

    George, A.D.; Wyrwoll, K.-H.; Jie, C.; Yanchou, L.

    1999-01-01

    Full text: Growth of the Tibetan Plateau along its northeastern margin by crustal shortening and thickening is linked to the Altyn Tagh Fault, a ∼1500 km long sinistral strike-slip fault which has played a significant role in accommodating the convergence of India and Eurasia. The NW-trending Qilian Shan (mountains) that mark the northeastern edge of the plateau rise nearly 5000 m above the adjacent Juice Basin of the Hexi Corridor. The Qilian Shan is a mid-Paleozoic orogenic suture belt composed of numerous thrust slices of deformed Lower Paleozoic (Cambrian-Silurian) metasedimentary and metavolcanic strata. The older Precambrian basement is also exposed in some thrust sheets, as are remnants of Upper Paleozoic-Jurassic strata. Cretaceous fluvial sandstones and conglomerates are locally preserved. The neighbouring Juice Basin contains a thick succession of Neogene-Quaternary fluvial strata (∼3.5 km thick) which unconformably overlies Lower Cretaceous rocks. Adjacent to the Qilian Shan, the oldest Neogene strata in the Juice Basin are Miocene in age overlain by more extensive Pliocene and Quaternary sediments, whereas basal Oligocene strata are exposed on the northern side of the basin. Neogene and Quaternary strata are being actively deformed by thrust-related folding along the margins and within the Jiuxi Basin. Apatite fission-track and vitrinite reflectance data were obtained from Precambrian to Tertiary outcrop samples from the northern Qilian Shan and Juice Basin to provide constraints on timing of exhumation and cooling. All the samples record multiple cooling episodes. Tertiary cooling from peak paleotemperatures (40-120 deg C) beginning sometime between 20 and 10 Ma (mid-Miocene) is common to all samples. This age is significantly older than previous models which proposed initiation of uplift in the Pliocene-Pleistocene, i.e., no older than 5-6 Ma. For any reasonable paleo-geothermal gradient, the degree of mid-Miocene cooling requires km

  3. Tim50a, a nuclear isoform of the mitochondrial Tim50, interacts with proteins involved in snRNP biogenesis

    Directory of Open Access Journals (Sweden)

    Robinson Melvin L

    2005-07-01

    Full Text Available Abstract Background The Cajal body (CB is a nuclear suborganelle involved in the biogenesis of small nuclear ribonucleoproteins (snRNPs, which are vital for pre-mRNA splicing. Newly imported Sm-class snRNPs traffic through CBs, where the snRNA component of the snRNP is modified, and then target to other nuclear domains such as speckles and perichromatin fibrils. It is not known how nascent snRNPs localize to the CB and are released from this structure after modification. The marker protein for CBs, coilin, may play a role in snRNP biogenesis given that it can interact with snRNPs and SMN, the protein mutated in Spinal Muscular Atrophy. Loss of coilin function in mice leads to significant viability and fertility problems and altered CB formation. Results In this report, we identify a minor isoform of the mitochondrial Tim50, Tim50a, as a coilin interacting protein. The Tim50a transcript can be detected in some cancer cell lines and normal brain tissue. The Tim50a protein differs only from Tim50 in that it contains an additional 103 aa N-terminal to the translation start of Tim50. Importantly, a putative nuclear localization signal is found within these 103 residues. In contrast to Tim50, which localizes to the cytoplasm and mitochondria, Tim50a is strictly nuclear and is enriched in speckles with snRNPs. In addition to coilin, Tim50a interacts with snRNPs and SMN. Competition binding experiments demonstrate that coilin competes with Sm proteins of snRNPs and SMN for binding sites on Tim50a. Conclusion Tim50a may play a role in snRNP biogenesis given its cellular localization and protein interaction characteristics. We hypothesize that Tim50a takes part in the release of snRNPs and SMN from the CB.

  4. Late cenozoic tectonic and geomorphic evolution of the Patagonian Andes between 42oS and 52oS, southern Chile assessed using fission-track thermochronology

    International Nuclear Information System (INIS)

    Thomson, S.N; Herve, F; Stockhert, B.; Brix, M.R.; Adriasola, A

    2001-01-01

    Fission-track (FT) analysis has been applied in the Patagonian Andes of southern Chile to assess the late Cenozoic geomorphic and tectonic response of the overriding plate to subduction of the Chile rise active oceanic spreading centre (Thomson et al., 2001). The timing and nature of tectonic uplift and denudation along the southern parts of the major transpression intra-arc Liquine-Ofqui fault (LOF) system have also been investigated (Thomson, 2001, submitted). Results from 130 FT ages (72 zircon and 58 apatite ages) and 39 apatite track length measurements reveal initiation of rapid cooling and denudation at ca. 30 Ma at the western margin of southern continental South America. This was followed by a ca. 200km eastward migration of the locus of maximum denudation to the position of the present day topographic divide between ca. 30 Ma and ca. 12 to 10 Ma. East of the Andean divide less than 3 km of denudation has occurred since the Late Cretaceous. Enhanced denudation is interpreted to be the result of increased tectonic uplift driven by a large increase in convergence rates at ca. 28 to 26 Ma that triggered orographically enhanced precipitation on the west-side of the Patagonian Andes allowing increased erosion by fluvial incision and mass transport processes. The eastward migration of the locus of maximum denudation can be related to either coeval eastward migration of the retro-arc deformation front, the effects of subduction erosion in the overriding plate at the Peru-Chile trench or shallowing of the angle of subduction. Away from the influence of the LOF the process of spreading centre subduction and collision itself coincides with an overall slow-down in denudation rates in the overriding plate most likely caused by a major reduction in the main tectonic force driving tectonic uplift in the upper plate to subduction. In contrast to the Andes south of ca. 46 o S, increased cooling and denudation related to transpression induced rock uplift and erosion along

  5. Chemical Production using Fission Fragments

    International Nuclear Information System (INIS)

    Dawson, J. K.; Moseley, F.

    1960-01-01

    Some reactor design considerations of the use of fission recoil fragment energy for the production of chemicals of industrial importance have been discussed previously in a paper given at the Second United Nations International Conference on the Peaceful Uses of Atomic Energy [A/Conf. 15/P.76]. The present paper summarizes more recent progress made on this topic at AERE, Harwell. The range-energy relationship for fission fragments is discussed in the context of the choice of fuel system for a chemical production reactor, and the experimental observation of a variation of chemical effect along the length of a fission fragment track is described for the irradiation of nitrogen-oxygen mixtures. Recent results are given on the effect of fission fragments on carbon monoxide-hydrogen gas mixtures and on water vapour. No system investigated to date shows any outstanding promise for large-scale chemical production. (author) [fr

  6. Ternary fission

    Indian Academy of Sciences (India)

    the energy minimization of all possible ternary breakups of a heavy radioactive nucleus. Further, within the TCM we have analysed the competition between different geometries as well as different positioning of the fragments. Also, an attempt was made to calculate the mass distribution of ternary fission process within the ...

  7. Tim Berners-Lee and Kofi Annan during the WSIS

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    During the 2003 World Summit on the Information Society (WSIS) at Geneva Palexpo, Tim Berners-Lee W3C's director (World Wide Web consortium) was introduced to Kofi Annan, Secretary General of the United Nations. Tim Berners-Lee developed the first network and server system that lead to the World Wide Web.

  8. Tim Berners-Lee and Kofi Annan during the WSIS

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    During the 2003 World Summit on the Information Society (WSIS) at Geneva Palexpo, Tim Berners-Lee, W3C's director (World Wide Web consortium) was introduced to Kofi Annan, Secretary General of the United Nations. Tim Berners-Lee developed the first network and server system that lead to the World Wide Web.

  9. Characterizing Functional Domains for TIM-Mediated Enveloped Virus Entry

    Science.gov (United States)

    Moller-Tank, Sven; Albritton, Lorraine M.; Rennert, Paul D.

    2014-01-01

    ABSTRACT T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members were recently identified as phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance entry of Ebola virus (EBOV) and other viruses by binding PtdSer on the viral envelope, concentrating virus on the cell surface, and promoting subsequent internalization. The PtdSer-binding activity of the immunoglobulin-like variable (IgV) domain is essential for both virus binding and internalization by TIM-1. However, TIM-3, whose IgV domain also binds PtdSer, does not effectively enhance virus entry, indicating that other domains of TIM proteins are functionally important. Here, we investigate the domains supporting enhancement of enveloped virus entry, thereby defining the features necessary for a functional PVEER. Using a variety of chimeras and deletion mutants, we found that in addition to a functional PtdSer-binding domain PVEERs require a stalk domain of sufficient length, containing sequences that promote an extended structure. Neither the cytoplasmic nor the transmembrane domain of TIM-1 is essential for enhancing virus entry, provided the protein is still plasma membrane bound. Based on these defined characteristics, we generated a mimic lacking TIM sequences and composed of annexin V, the mucin-like domain of α-dystroglycan, and a glycophosphatidylinositol anchor that functioned as a PVEER to enhance transduction of virions displaying Ebola, Chikungunya, Ross River, or Sindbis virus glycoproteins. This identification of the key features necessary for PtdSer-mediated enhancement of virus entry provides a basis for more effective recognition of unknown PVEERs. IMPORTANCE T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members are recently identified phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance virus entry by binding the phospholipid, PtdSer, present on the viral

  10. Tim Berners-Lee receives the Millennium Technology Prize

    CERN Multimedia

    2004-01-01

    On 15 April, for his invention of the Web, Tim Berners-Lee was awarded the first ever Millennium Technology Prize by the Finnish Technology Award Foundation, which recognises technological innovations of lasting benefit to society. "Tim Berners-Lee's invention perfectly encapsulates the spirit of the Prize. The Web is encouraging new types of social networks, contributing to transparency and democracy, and opening up new avenues for information management and business development," underlined Pekka Tarjanne, chairman of the jury and former Secretary-General of the International Telecommunication Union (ITU). Tim Berners-Lee is congratulated by Jukka Valtasaari, Finland's Ambassador to the United States. Tim Berners-Lee created the first server, browser and editor, the HTML code, the URL address and the HTTP transmission protocol at CERN in 1990. CERN released the Web into the public domain in 1993. Tim Berners-Lee is currently head of the World Wide Web Consortium, managed by ERCIM (Europe...

  11. Mass dependence of positive pion-induced fission

    International Nuclear Information System (INIS)

    Khan, H.A.; Khan, N.A.; Peterson, R.J.

    1991-01-01

    Fission cross sections for a range of targets have been measured by solid-state track detectors following 80 and 100 MeV π + bombardment. Fission probabilities have been inferred by comparison to computed reaction cross sections. Fission probabilities for heavy targets agree with those for other probes of comparable energy and with statistical calculations. Probabilities for lighter targets are much above those previously observed or computed. Ternary fission cross sections and multiplicities of light fragments have also been determined

  12. A listing of cosmogenic, optically-stimulated-luminescence, (U-Th)/He, and fission-track sample locations, analyses, and age data compiled as part of Marsden contract GNS002 (2000-2004) : subduction initiation beneath Fiordland, southwest New Zealand

    International Nuclear Information System (INIS)

    Sutherland, R.

    2007-01-01

    This report is an archive of data relevant to Fiordland tectonic evolution. Specifically these are the data that were collected and compiled as part of Marsden contract GNS002 (2000-2004); samples were collected between 1987 and 2002. The principal investigator of the Marsden Fund project was Rupert Sutherland (GNS Science). Additional named investigators (with responsibilities and affiliations) were: Kyeong Kim (cosmogenic isotope dating; GNS Science); Peter Kamp (fission track dating; Waikato University); Martha House (U-Th/He dating; Caltech, USA); and Michael Gurnis (numerical models of subduction initiation; Caltech, USA). After the project began, Uwe Rieser from Victoria University agreed to undertake optically-stimulated luminescence (OSL) dating as part of the project. (author). 6 refs

  13. Cumulative fission yield of Ce-148 produced by thermal-neutron fission of U-235

    International Nuclear Information System (INIS)

    Hasan, A.A.

    1984-12-01

    Cumulative fission yield of 148 cesium isotopes and some other fission products produced by thermal-neutron fission of 235 uranium is determined by Germanium/Lithium spectroscopic methods. The measuremets were done at Tsing-Hua open pool reactor using 3 to 4 mg of 93.15% enriched 235 uranium samples. Gamma rays are assigned to the responsible fission products by matching gamma rays energies and half lives. Fission rate is calculated by fission track method. Cumulative fission yields of 148 cesium, 90 krypton, 130 iodine, 144 lanthanum, 89 krypton, 136 xenon, 137 xenon and 140 cesium are calculated. This values are compared with previously predicted values and showed good agreement. 21 Ref

  14. Project TIMS (Teaching Integrated Math/Science)

    Science.gov (United States)

    Edwards, Leo, Jr.

    1993-01-01

    The goal of this project is to increase the scientific knowledge and appreciation bases and skills of pre-service and in-service middle school teachers, so as to impact positively on teaching, learning, and student retention. This report lists the objectives and summarizes the progress thus far. Included is the working draft of the TIMS (Teaching Integrated Math/Science) curriculum outline. Seven of the eight instructional subject-oriented modules are also included. The modules include informative materials and corresponding questions and educational activities in a textbook format. The subjects included here are the universe and stars; the sun and its place in the universe; our solar system; astronomical instruments and scientific measurements; the moon and eclipses; the earth's atmosphere: its nature and composition; and the earth: directions, time, and seasons. The module not included regards winds and circulation.

  15. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  16. Fission meter

    Science.gov (United States)

    Rowland, Mark S [Alamo, CA; Snyderman, Neal J [Berkeley, CA

    2012-04-10

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source.

  17. TIM-1 signaling in B cells regulates antibody production

    International Nuclear Information System (INIS)

    Ma, Juan; Usui, Yoshihiko; Takeda, Kazuyoshi; Harada, Norihiro; Yagita, Hideo; Okumura, Ko; Akiba, Hisaya

    2011-01-01

    Highlights: → TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. → Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. → TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3 + anti-CD28-stimulated CD4 + T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

  18. TIM-1 signaling in B cells regulates antibody production

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Juan [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Usui, Yoshihiko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Ophthalmology, Tokyo Medical University, 6-7-1 Nishi-shinjuku-ku, Tokyo 160-0023 (Japan); Takeda, Kazuyoshi [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Norihiro [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Department of Respiratory Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Research Institute for Diseases of Old Ages, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Yagita, Hideo; Okumura, Ko [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Akiba, Hisaya, E-mail: hisaya@juntendo.ac.jp [Department of Immunology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2011-03-11

    Highlights: {yields} TIM-1 is highly expressed on anti-IgM + anti-CD40-stimulated B cells. {yields} Anti-TIM-1 mAb enhanced proliferation and Ig production on activated B cell in vitro. {yields} TIM-1 signaling regulates Ab production by response to TI-2 and TD antigens in vivo. -- Abstract: Members of the T cell Ig and mucin (TIM) family have recently been implicated in the control of T cell-mediated immune responses. In this study, we found TIM-1 expression on anti-IgM- or anti-CD40-stimulated splenic B cells, which was further up-regulated by the combination of anti-IgM and anti-CD40 Abs. On the other hand, TIM-1 ligand was constitutively expressed on B cells and inducible on anti-CD3{sup +} anti-CD28-stimulated CD4{sup +} T cells. In vitro stimulation of activated B cells by anti-TIM-1 mAb enhanced proliferation and expression of a plasma cell marker syndecan-1 (CD138). We further examined the effect of TIM-1 signaling on antibody production in vitro and in vivo. Higher levels of IgG2b and IgG3 secretion were detected in the culture supernatants of the anti-TIM-1-stimulated B cells as compared with the control IgG-stimulated B cells. When immunized with T-independent antigen TNP-Ficoll, TNP-specific IgG1, IgG2b, and IgG3 Abs were slightly increased in the anti-TIM-1-treated mice. When immunized with T-dependent antigen OVA, serum levels of OVA-specific IgG2b, IgG3, and IgE Abs were significantly increased in the anti-TIM-1-treated mice as compared with the control IgG-treated mice. These results suggest that TIM-1 signaling in B cells augments antibody production by enhancing B cell proliferation and differentiation.

  19. Ideological Fission

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    ; it is a materialisation of an ideological fission which attempts to excise certain ideological constructions, yet paradoxically casting them in a form that is recognizable and familiar. The monstrous metonomy which is used shows us glimpses of a horrid being, intended to vilify the attack on New York City. However......, it is a being which is reminiscent of earlier monsters - from Godzilla to The Blob. It is evident that the Cloverfield monster is a paradoxical construction which attempts to articulate fear and loathing about terrorism, but ends up trapped in an ideological dead-end maze, unable to do anything other than...

  20. Meet EPA Scientist Tim Shafer, Ph.D.

    Science.gov (United States)

    Tim Shafer earned his bachelor’s degree in biology and chemistry from Hope College in Holland, MI, in 1986 and his Ph.D. in pharmacology and environmental toxicology from Michigan State University in 1991.

  1. Mica fission detectors

    International Nuclear Information System (INIS)

    Wong, C.; Anderson, J.D.; Hansen, L.; Lehn, A.V.; Williamson, M.A.

    1977-01-01

    The present development status of the mica fission detectors is summarized. It is concluded that the techniques have been refined and developed to a state such that the mica fission counters are a reliable and reproducible detector for fission events

  2. Response to Tim Barringer, A White Atlantic?

    Directory of Open Access Journals (Sweden)

    Kate Flint

    2009-11-01

    Full Text Available In my response to Tim Barringer’s piece, I emphasize the importance of extending one’s frame of reference when discussing transatlantic artistic connections to the consideration of as many different art forms as possible – including photography, and magazine and book illustrations – in order to get as full a picture as possible of the two-way flow in transatlantic artistic influences.This fuller picture notably extends the degree to which images of non-white subjects are seen to be in circulation. I also draw attention to the ways in which American and English artistic circles intersected outside as well as within these two countries, a point reinforced by looking at American women sculptors in Rome in the 1860s, paying particular attention to the work of the part African-American, part Native American sculptor, Edmonia Lewis. In her work can be seen a complex set of attitudes towards her subject matter that remind one forcefully of the many racial and cultural strands coming together in new American art.

  3. Tim Berners-Lee, World Wide Web inventor

    CERN Multimedia

    1994-01-01

    Former physicist, Tim Berners-Lee invented the World Wide Web as an essential tool for high energy physics at CERN from 1989 to 1994. Together with a small team he conceived HTML, http, URLs, and put up the first server and the first 'what you see is what you get' browser and html editor. Tim is now Director of the Web Consortium W3C, the International Web standards body based at INRIA, MIT and Keio University.

  4. Isotopic Ratios of Samarium by TIMS for Nuclear Forensic Application

    Energy Technology Data Exchange (ETDEWEB)

    Louis Jean, James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Inglis, Jeremy David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-08

    The isotopic ratio of Nd, Sm, and Gd can provide important information regarding fissile material (nuclear devices, reactors), neutron environment, and device yield. These studies require precise measurement of Sm isotope ratios, by either TIMS or MC-ICP-MS. There has been an increasing trend to measure smaller and smaller quantities of Sm bearing samples. In nuclear forensics 10-100 ng of Sm are needed for precise measurement. To measure sub-ng Sm samples using TIMS for nuclear forensic analysis.

  5. There are those who call it...TIM

    CERN Multimedia

    2007-01-01

    To boldly go where people can't... The Train Inspection Monorail, affectionately referred to as 'TIM,' will allow scientists, technicians and engineers to view and take measurements in the LHC tunnel when it is inaccessible to humans. TIM in the tunnel.Jean-Louis Grenard, who designed TIM's mechanical components, uses the portable remote control station to put the TIM through its paces at Point 1 in the LHC. Imagine being able to view parts of the LHC before people are allowed into the tunnel after the beam has been circulating...or to accurately measure the position of equipment in areas with the highest levels of radiation without risking human exposure. The Train Inspection Monorail, or 'TIM' to its closer friends, is a modular train that will run along the ceiling of the LHC tunnel, helping many groups on site to address the problems of inspecting, measuring and even handling equipment in the LHC when radiation levels and cryogenic hazards will restrict personnel access to the tunnel. TIM was developed ...

  6. Resolving the age of the first-order topography of southern Africa: new insight from joint (U-Th)/He and fission track dating of samples from deep boreholes

    Science.gov (United States)

    Beucher, R.; Brown, R. W.; Persano, C.; Stuart, F.; Gallagher, K.

    2011-12-01

    The topography of Africa is unusually high with respect to other continents and its origin remains strongly debated. Africa's topography is strongly bimodal as it is distributed between the high plateau areas in its central part (circa 1000 m), and significantly less elevated areas with higher relief around its borders. The geodynamical interpretation of this feature is not straightforward as the plateau is essentially surrounded by passive margins and oceanic ridges. However, abundant seismic studies have revealed a deep seismic anomaly beneath Africa and suggest that forces related to active upward flow within the mantle are dynamically sustaining its high elevation. If the large anomaly provides a mechanism explaining the south African plateau, a lot of questions remain on the timing of uplift. Geodynamic models allow Africa to go up or down but fail to put constrains on the age of the uplift. This is mainly because of a lack of tight constraints on the viscosity and density structure of the mantle, which lead to several models with uplift occurring either during Cretaceous or Miocene times. The question of the age of the plateau therefore remains unresolved. Thermochronology and techniques such as fission track and U-Th/He analyses provide tools to address this question by constraining the erosion history. In this study we take advantage of the availability of deep boreholes located all across south-Africa to sample truly vertical profiles through the plateau. The key advantage of this approach is that it enables constraints to be placed on the timing and amount of cooling resulting from relatively low amounts of erosion. A dozen boreholes from above and below the great escarpment have been sampled. We present fission track and U-Th/He results for three of them. The U-Th/He analyses are performed as single grain analyses with an average number of 15+ aliquots per sample for a total of 250+ single grain analyses in order to provide a high resolution chronology

  7. Solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Medeiros, J.A.; Carvalho, M.L.C.P. de

    1992-12-01

    Solid state nuclear track detectors (SSNTD) are dielectric materials, crystalline or vitreous, which registers tracks of charged nuclear particles, like alpha particles or fission fragments. Chemical etching of the detectors origin tracks that are visible at the optical microscope: track etching rate is higher along the latent track, where damage due to the charged particle increase the chemical potential, and etching rate giving rise to holes, the etched tracks. Fundamental principles are presented as well as some ideas of main applications. (author)

  8. Mesozoic-Cenozoic evolution of the Zoige depression in the Songpan-Ganzi flysch basin, eastern Tibetan Plateau: Constraints from detrital zircon U-Pb ages and fission-track ages of the Triassic sedimentary sequence

    Science.gov (United States)

    Tang, Yan; Zhang, Yunpeng; Tong, Lili

    2018-01-01

    The Zoige depression is an important depocenter within the northeast Songpan-Ganzi flysch basin, which is bounded by the South China, North China and Qiangtang Blocks and forms the northeastern margin of the Tibetan Plateau. This paper discusses the sediment provenance and Mesozoic-Cenozoic evolution of the Zoige depression in the Songpan-Ganzi flysch basin, eastern Tibetan Plateau, using the detrital zircon U-Pb ages and apatite fission-track data from the Middle to Late Triassic sedimentary rocks in the area. The U-Pb ages of the Middle to Late Triassic zircons range from 260-280 Ma, 429-480 Ma, 792-974 Ma and 1800-2500 Ma and represent distinct source region. Our new results demonstrate that the detritus deposited during the Middle Triassic (Ladinian, T2zg) primarily originated from the Eastern Kunlun and North Qinling Orogens, with lesser contributions from the North China Block. By the Late Triassic (early Carnian, T3z), the materials at the southern margin of the North China Block were generally transported westward to the basin along a river network that flowed through the Qinling region between the North China and South China Blocks: this interpretation is supported by the predominance of the bimodal distribution of 1.8 Ga and 2.5 Ga age peaks and a lack of significant Neoproterozoic zircon. Since the Late Triassic (middle Carnian, T3zh), considerable changes have occurred in the source terranes, such as the cessation of the Eastern Kunlun Orogen and North China Block sources and the rise of the northwestern margin of the Yangtze Block and South Qinling Orogen. These drastic changes are compatible with a model of a sustained westward collision between the South China and North China Blocks during the late Triassic and the clockwise rotation of the South China Block progressively closed the basin. Subsequently, orogeny-associated folds have formed in the basin since the Late Triassic (late Carnian), and the study area was generally subjected to uplifting and

  9. Fission cross section measurements for minor actinides

    Energy Technology Data Exchange (ETDEWEB)

    Fursov, B. [IPPE, Obninsk (Russian Federation)

    1997-03-01

    The main task of this work is the measurement of fast neutron induced fission cross section for minor actinides of {sup 238}Pu, {sup 242m}Am, {sup 243,244,245,246,247,248}Cm. The task of the work is to increase the accuracy of data in MeV energy region. Basic experimental method, fissile samples, fission detectors and electronics, track detectors, alpha counting, neutron generation, fission rate measurement, corrections to the data and error analysis are presented in this paper. (author)

  10. Fission theory and actinide fission data

    Energy Technology Data Exchange (ETDEWEB)

    Michaudon, A.

    1975-06-01

    The understanding of the fission process has made great progress recently, as a result of the calculation of fission barriers, using the Strutinsky prescription. Double-humped shapes were obtained for nuclei in the actinide region. Such shapes could explain, in a coherent manner, many different phenomena: fission isomers, structure in near-threshold fission cross sections, intermediate structure in subthreshold fission cross sections and anisotropy in the emission of the fission fragments. A brief review of fission barrier calculations and relevant experimental data is presented. Calculations of fission cross sections, using double-humped barrier shapes and fission channel properties, as obtained from the data discussed previously, are given for some U and Pu isotopes. The fission channel theory of A. Bohr has greatly influenced the study of low-energy fission. However, recent investigation of the yields of prompt neutrons and γ rays emitted in the resonances of {sup 235}U and {sup 239}Pu, together with the spin determination for many resonances of these two nuclei cannot be explained purely in terms of the Bohr theory. Variation in the prompt neutron and γ-ray yields from resonance to resonance does not seem to be due to such fission channels, as was thought previously, but to the effect of the (n,γf) reaction. The number of prompt fission neutrons and the kinetic energy of the fission fragments are affected by the energy balance and damping or viscosity effects in the last stage of the fission process, from saddle point to scission. These effects are discussed for some nuclei, especially for {sup 240}Pu.

  11. Reconstituted TOM core complex and Tim9/Tim10 complex of mitochondria are sufficient for translocation of the ADP/ATP carrier across membranes.

    Science.gov (United States)

    Vasiljev, Andreja; Ahting, Uwe; Nargang, Frank E; Go, Nancy E; Habib, Shukry J; Kozany, Christian; Panneels, Valérie; Sinning, Irmgard; Prokisch, Holger; Neupert, Walter; Nussberger, Stephan; Rapaport, Doron

    2004-03-01

    Precursor proteins of the solute carrier family and of channel forming Tim components are imported into mitochondria in two main steps. First, they are translocated through the TOM complex in the outer membrane, a process assisted by the Tim9/Tim10 complex. They are passed on to the TIM22 complex, which facilitates their insertion into the inner membrane. In the present study, we have analyzed the function of the Tim9/Tim10 complex in the translocation of substrates across the outer membrane of mitochondria. The purified TOM core complex was reconstituted into lipid vesicles in which purified Tim9/Tim10 complex was entrapped. The precursor of the ADP/ATP carrier (AAC) was found to be translocated across the membrane of such lipid vesicles. Thus, these components are sufficient for translocation of AAC precursor across the outer membrane. Peptide libraries covering various substrate proteins were used to identify segments that are bound by Tim9/Tim10 complex upon translocation through the TOM complex. The patterns of binding sites on the substrate proteins suggest a mechanism by which portions of membrane-spanning segments together with flanking hydrophilic segments are recognized and bound by the Tim9/Tim10 complex as they emerge from the TOM complex into the intermembrane space.

  12. Fission fragment angular distributions and fission cross section validation

    International Nuclear Information System (INIS)

    Leong, Lou Sai

    2013-01-01

    The present knowledge of angular distributions of neutron-induced fission is limited to a maximal energy of 15 MeV, with large discrepancies around 14 MeV. Only 238 U and 232 Th have been investigated up to 100 MeV in a single experiment. The n-TOF Collaboration performed the fission cross section measurement of several actinides ( 232 Th, 235 U, 238 U, 234 U, 237 Np) at the n-TOF facility using an experimental set-up made of Parallel Plate Avalanche Counters (PPAC), extending the energy domain of the incident neutron above hundreds of MeV. The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. I will show the methods we used to reconstruct the full angular resolution by the tracking of fission fragments. Below 10 MeV our results are consistent with existing data. For example in the case of 232 Th, below 10 MeV the results show clearly the variation occurring at the first (1 MeV) and second (7 MeV) chance fission, corresponding to transition states of given J and K (total spin and its projection on the fission axis), and a much more accurate energy dependence at the 3. chance threshold (14 MeV) has been obtained. In the spallation domain, above 30 MeV we confirm the high anisotropy revealed in 232 Th by the single existing data set. I'll discuss the implications of this finding, related to the low anisotropy exhibited in proton-induced fission. I also explore the critical experiments which is valuable checks of nuclear data. The 237 Np neutron-induced fission cross section has recently been measured in a large energy range (from eV to GeV) at the n-TOF facility at CERN. When compared to previous measurements, the n-TOF fission cross section appears to be higher by 5-7 % beyond the fission threshold. To check the relevance of n-TOF data, we simulate a criticality experiment performed at Los Alamos with a 6 kg sphere of 237 Np. This

  13. Mass distribution of fission fragments using SSNTDs based image analysis system

    International Nuclear Information System (INIS)

    Kolekar, R.V.; Sharma, D.N.

    2006-01-01

    Lexan polycarbonate track detector was used to obtain mass distribution of fission fragments from 252 Cf planchette source, Normally, if the fission fragments are incident perpendicular to the lexan surface, the diameter of heavy fragment is greater than that of lighter fragment. In practical problems fission fragments are incident on the detector at all angles. So, in the present experiment, lexan detector was exposed to 252 Cf planchette source in 2π geometry. Fission fragments were incident on the detector with various angles. So the projected fission track length for fission fragment of same energy is different because of different angle of incidence. Image analysis software was used to measure the projected track length. But the problem is that for fission fragment having greater angle of incidence the entire track length is not focused on the surface. So reduced track length is measured. This problem is solved by taking two images, one at the surface and one at the tip of track and then overlapping both the images using image analysis software. The projected track length and the depth of the track were used to get the angle of incidence. Fission track lengths were measured for same angle of incidence. In all 500 track lengths were measured and plot for mass distribution for fission fragment was obtained.(author)

  14. Nuclear fission and reactions

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The nuclear fission research programs are designed to elucidate basic features of the fission process. Specifically, (1) factors determining how nucleons of a fissioning nucleus are distributed between two fission fragments, (2) factors determining kinetic energy and excitation energies of fragments, and (3) factors controlling fission lifetimes. To these ends, fission studies are reported for several heavy elements and include investigations of spontaneous and neutron-induced fission, heavy ion reactions, and high energy proton reactions. The status of theoretical research is also discussed. (U.S.)

  15. Analysis of TIMS performance subjected to simulated wind blast

    Science.gov (United States)

    Jaggi, S.; Kuo, S.

    1992-01-01

    The results of the performance of the Thermal Infrared Multispectral Scanner (TIMS) when it is subjected to various wind conditions in the laboratory are described. Various wind conditions were simulated using a 24 inch fan or combinations of air jet streams blowing toward either or both of the blackbody surfaces. The fan was used to simulate a large volume of air flow at moderate speeds (up to 30 mph). The small diameter air jets were used to probe TIMS system response in reaction to localized wind perturbations. The maximum nozzle speed of the air jet was 60 mph. A range of wind directions and speeds were set up in the laboratory during the test. The majority of the wind tests were conducted under ambient conditions with the room temperature fluctuating no more than 2 C. The temperature of the high speed air jet was determined to be within 1 C of the room temperature. TIMS response was recorded on analog tape. Additional thermistor readouts of the blackbody temperatures and thermocouple readout of the ambient temperature were recorded manually to be compared with the housekeeping data recorded on the tape. Additional tests were conducted under conditions of elevated and cooled room temperatures. The room temperature was varied between 19.5 to 25.5 C in these tests. The calibration parameters needed for quantitative analysis of TIMS data were first plotted on a scanline-by-scanline basis. These parameters are the low and high blackbody temperature readings as recorded by the TIMS and their corresponding digitized count values. Using these values, the system transfer equations were calculated. This equation allows us to compute the flux for any video count by computing the slope and intercept of the straight line that relates the flux to the digital count. The actual video of the target (the lab floor in this case) was then compared with a simulated target. This simulated target was assumed to be a blackbody at emissivity of .95 degrees and the temperature was

  16. Using slope-area and apatite fission track analysis to decipher the rock uplift pattern of the Yumu Shan: New insights into the growth of the NE Tibetan Plateau

    Science.gov (United States)

    Wang, Yizhou; Zheng, Dewen; Pang, Jianzhang; Zhang, Huiping; Wang, Weitao; Yu, Jingxing; Zhang, Zhuqi; Zheng, Wenjun; Zhang, Peizhen; Li, Youjuan

    2018-05-01

    Studies have shown that the growth of the Qilian Shan, the northeastern margin of the Tibetan Plateau, started 10 Ma ago. However, when and how it expanded northwards is still under debate. Here we focus on the rock uplift pattern of the Yumu Shan, an active fault-related fold in the Hexi Corridor north to the Qilian Shan. Normalized channel steepness achieved from the analysis of river longitudinal profiles shows a spatially variant rock uplift pattern, with higher rates in the middle part and lower rates towards the west and east tips. The compression of the mountain is typically accommodated by fault-fold related shortening and vertical thickening. Apatite fission track thermochronology reveals that the growth of the Yumu Shan started 4 Ma ago, similar to the work on active tectonics. Combining the onset ages of the growth of the Qilian Shan (10 Ma), Laojunmiao anticline (3-4 Ma), Baiyanghe anticline (3-4 Ma), Wenshu Shan (4.5 Ma) and Heli Shan (2 Ma), we draw an conclusion that the NE margin of the Tibetan Plateau initiated growth in the mid-Miocene and expanded to the Hexi Corridor and to the south of the Alxa block in the early Pleistocene.

  17. Recognition of Cretaceous, Paleocene, and Neogene tectonic reactivation through apatite fission-track analysis in Precambrian areas of southeast Brazil: association with the opening of the south Atlantic Ocean

    Science.gov (United States)

    Tello Saenz, C. A.; Hackspacher, P. C.; Hadler Neto, J. C.; Iunes, P. J.; Guedes, S.; Ribeiro, L. F. B.; Paulo, S. R.

    2003-01-01

    Apatite fission-track analysis was used for the determination of thermal histories and ages in Precambrian areas of southeast Brazil. Together with geological and geomorphologic information, these ages enable us to quantify the thermal histories and timing of Mesozoic and Cenozoic epirogenic and tectonic processes. The collected samples are from different geomorphologic blocks: the high Mantiqueira mountain range (HMMR) with altitude above 1000 m, the low Mantiqueira mountain range (LMMR) under 1000 m, the Serra do Mar mountain range (SMMR), the Jundiaí and Atlantic Plateaus, and the coastline, all of which have distinct thermal histories. During the Aptian (˜120 Ma), there was an uplift of the HMMR, coincident with opening of the south Atlantic Ocean. Its thermal history indicates heating (from ˜60 to ˜80 °C) until the Paleocene, when rocks currently exposed in the LMMR reached temperatures of ˜100 °C. In this period, the Serra do Mar rift system and the Japi erosion surface were formed. The relief records the latter. During the Late Cretaceous, the SMMR was uplifted and probably linked to its origin; in the Tertiary, it experienced heating from ˜60 to ˜90 °C, then cooling that extends to the present. The SMMR, LMMR, and HMMR were reactivated mainly in the Paleocene, and the coastline during the Paleogene. These processes are reflected in the sedimentary sequences and discordances of the interior and continental margin basins.

  18. Measurements of fission yields

    International Nuclear Information System (INIS)

    Denschlag, H.O.

    2000-01-01

    After some historical introductory remarks on the discovery of nuclear fission and early fission yield determinations, the present status of knowledge on fission yields is briefly reviewed. Practical and fundamental reasons motivating the pursuit of fission yield measurements in the coming century are pointed out. Recent results and novel techniques are described that promise to provide new interesting insights into the fission process during the next century. (author)

  19. Radiochemical studies on fission

    Energy Technology Data Exchange (ETDEWEB)

    None

    1973-07-01

    Research progress is reported on nuclear chemistry; topics considered include: recoil range and kinetic energy distribution in the thermal neutron ftssion of /sup 245/Cm; mass distribution and recoil range measurements in the reactor neutron-induced fission of /sup 232/U; fission yields in the thermal neutron fission of /sup 241/PU highly asymmetric binary fission of uranium induced by reactor neutrons; and nuclear charge distribution in low energy fission. ( DHM)

  20. Thermal and tectonic history of the Barrandian Lower Paleozoic, Czech Republic: is there a fission-track evidence for Carboniferous-Permian overburden and pre-Westphalian alpinotype thrusting? (Critical comments on the paper by Ulrich Mann and Günter A. Wagner)

    Czech Academy of Sciences Publication Activity Database

    Filip, Jiří; Suchý, V.

    2004-01-01

    Roč. 79, č. 2 (2004), s. 107-112 ISSN 1214-1119 R&D Projects: GA AV ČR(CZ) IAA3012703 Grant - others:DFG(DE) Ma 1861/1-1 Keywords : apatite fission-track analysis * Barrandian * Variscan Orogeny Subject RIV: DB - Geology ; Mineralogy http://www.geology.cz/bulletin/contents/2004/vol79no2/bullgeosci200402107.pdf

  1. Application of the dating by fission tracks to determine thermicity of basins within petroleum potentialities: example of Sbaa and Ahnet-North basins located in Western Saharan platform, Algeria

    International Nuclear Information System (INIS)

    Akkouche, M.

    2007-05-01

    The interpretation of old fundamental research works and the results obtained by this study based on: the analysis of apatite fission tracks (AFT), the burial evolution curves and the sequential analysis of outcrop section, as well as the curves of signal of gamma ray (GR) analysis from drilling wells, allow to precise that the geodynamic evolution of the studied Algerian sedimentary basins (Ahnet and Sbaa) have been occurred principally in the Paleozoic era. The analysis of burial evolution curves shows that during the Paleozoic period, the sedimentation is controlled by the tectonic subsidence, particularly at the end of Carboniferous in the favor of Ougarta folding. The curves indicate an uplift from the Permian to middle Jurassic, expressed by an important erosion of sedimentary series and is considered as a response of thermal convection of the Saharan platform followed by thermal subsidence. This can be explained by the halt motion of rift extension caused by the opening of the Atlantic Ocean. To bring the sequential analysis out, it appears that Ahnet and Sbaa basins present contrasted stratigraphic recordings, so much in time than in space, indicated the different effects from subsidence and erosions according to their sectors. In thermal point of view, temperatures are still moderate in Sbaa depression and favorite the preservation of organic matter and might generate hydrocarbons until now. However, these conditions are not similar to ones in the case of Ahnet basin. In the North part of Ahnet basin (MRS-1, MSL-1), the ages are around 50 Ma, attested that sedimentary layers have been sustained a post-Hercynian thermal phase. This phase could be estimated probably more than 100 C. This is also produced during the regional extension of the Triassic-Jurassic rifting. This episode could also be responsible of disappearance (total?) of pre-existence fission tracks in the Devonian layers of the well MSR-1, which exhibits at the depth 505 m under the Hercynian

  2. Fission- and alpha-track study of biogeochemistry of plutonium and uranium in carbonates of Bikini and Enewetak atolls. Progress report, January 1, 1976--December 31, 1976

    International Nuclear Information System (INIS)

    Levy, Y.; Miller, D.S.; Friedman, G.M.

    1976-09-01

    Alpha emitters have been detected with a resolution of a few tens of micrometers using a solid state track detector (cellulose nitrate) to map the activity in a coral sample from Bikini. Calibration methods used include: a Pu source of 0.15 μCi in conjunction with polycarbonate and CaCO 3 absorbers of different thicknesses (2 to 30 micrometers), and a powdered coral sample which had been analyzed previously for alpha emitters by chemical methods in conjunction with an alpha spectrometer. 0.04 mm 3 can be measured routinely; smaller concentrations can be determined but with a lower resolution. CaCO 3 of the coral Favites virens from Bikini lagoon was analyzed by placing the detector directly on the sample for thirty days. Sections and thin sections cut perpendicular to one another, but parallel to the direction of coral growth, give very different concentrations and distributions of alpha emitters. Maximum concentrations of 800 pCi/g were measured in a volume of 0.004 mm 3 in void-filling cement separated from the coral and in an area in which coral skeleton and cement could not be distinguished. Areas of high alpha emitter concentrations coincide with areas of coral growth interruption where non coral material exists that is composed of a mixture of encrusting bryozoan like carbonate material and skeletal debris

  3. Fission products collecting devices

    International Nuclear Information System (INIS)

    Matsumoto, Hiroshi

    1979-01-01

    Purpose: To enable fission products trap with no contamination to coolants and cover gas by the provision of a fission products trap above the upper part of a nuclear power plant. Constitution: Upon fuel failures in a reactor core, nuclear fission products leak into coolants and move along the flow of the coolants to the coolants above the reactor core. The fission products are collected in a trap container and guided along a pipeline into fission products detector. The fission products detector monitors the concentration of the fission products and opens the downstream valve of the detector when a predetermined concentration of the fission products is detected to introduce the fission products into a waste gas processing device and release them through the exhaust pipe. (Seki, T.)

  4. Energy released in fission

    International Nuclear Information System (INIS)

    James, M.F.

    1969-05-01

    The effective energy released in and following the fission of U-235, Pu-239 and Pu-241 by thermal neutrons, and of U-238 by fission spectrum neutrons, is discussed. The recommended values are: U-235 ... 192.9 ± 0.5 MeV/fission; U-238 ... 193.9 ± 0.8 MeV/fission; Pu-239 ... 198.5 ± 0.8 MeV/fission; Pu-241 ... 200.3 ± 0.8 MeV/fission. These values include all contributions except from antineutrinos and very long-lived fission products. The detailed contributions are discussed, and inconsistencies in the experimental data are pointed out. In Appendix A, the contribution to the total useful energy release in a reactor from reactions other than fission are discussed briefly, and in Appendix B there is a discussion of the variations in effective energy from fission with incident neutron energy. (author)

  5. Thermal ionisation mass spectrometry (TIMS): what, how and why?

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2002-01-01

    Thermal ionisation mass spectrometry (TIMS) is one of the oldest mass spectrometric techniques, which has been used for determining the isotopic composition and concentration of different elements using isotope dilution. In spite of the introduction of many other inorganic mass spectrometric techniques like spark source mass spectrometry (SSMS), glow discharge mass spectrometry (GDMS), inductively coupled plasma-mass spectrometry (ICP-MS), secondary ion mass spectrometry (SIMS), the TIMS technique plays the role of a definitive analytical methodology and still occupies a unique position in terms of its capabilities with respect to precision and accuracy as well as sensitivity

  6. Awards: New Year Knighthood for Tim Berners-Lee

    CERN Multimedia

    2004-01-01

    Tim Berners-Lee has been awarded his country's highest honour - a knighthood - in the UK's New Year Honours list for his work while at CERN on the World Wide Web. In the same honours list, Roger Cashmore has been made a Companion of the Order of St Michael and St George (CMG) "for his services to international co-operation in particle physics". Cashmore was CERN's Director for Collider Programmes from 1999-2003, and is now Principal of Brasenose College, Oxford. Tim Berners-Lee stands in front of the first web server at Palexpo during the World Summit on the Information Society.

  7. A highly conserved tyrosine of Tim-3 is phosphorylated upon stimulation by its ligand galectin-9

    International Nuclear Information System (INIS)

    Weyer, Philipp S. van de; Muehlfeit, Michael; Klose, Christoph; Bonventre, Joseph V.; Walz, Gerd; Kuehn, E. Wolfgang

    2006-01-01

    Tim-3 is a member of the TIM family of proteins (T-cell immunoglobulin mucin) involved in the regulation of CD4+ T-cells. Tim-3 is a T H 1-specific type 1 membrane protein and regulates T H 1 proliferation and the development of tolerance. Binding of galectin-9 to the extracellular domain of Tim-3 results in apoptosis of T H 1 cells, but the intracellular pathways involved in the regulatory function of Tim-3 are unknown. Unlike Tim-1, which is expressed in renal epithelia and cancer, Tim-3 has not been described in cells other than neuronal or T-cells. Using RT-PCR we demonstrate that Tim-3 is expressed in malignant and non-malignant epithelial tissues. We have cloned Tim-3 from an immortalized liver cell carcinoma line and identified a highly conserved tyrosine in the intracellular tail of Tim-3 (Y265). We demonstrate that Y265 is specifically phosphorylated in vivo by the interleukin inducible T cell kinase (ITK), a kinase which is located in close proximity of the TIM genes on the allergy susceptibility locus 5q33.3. Stimulation of Tim-3 by its ligand galectin-9 results in increased phosphorylation of Y265, suggesting that this tyrosine residue plays an important role in downstream signalling events regulating T-cell fate. Given the role of TIM proteins in autoimmunity and cancer, the conserved SH2 binding domain surrounding Y265 could represent a possible target site for pharmacological intervention

  8. SEM/TIMS analysis trials on hotswipe samples taken from a shielded cell at Harwell

    International Nuclear Information System (INIS)

    Tushingham, J.; Vatter, I.; Cooke, R.

    1998-09-01

    The IAEA require advanced techniques and procedures for the detection of traces of actinides to be applied to their environmental sampling programme for nuclear safeguards as a means to detect undeclared activities. 'Swipe' samples taken from within nuclear facilities by IAEA inspectors require analysis to determine their actinide content and composition by bulk and particle measurements. The use of analytical equipment capable of analysing individual particles, particularly of actinides, is essential to optimise the IAEA's aim to monitor Member State's nuclear activities more proficiently. A trial has been undertaken at the Harwell Laboratory of AEA Technology to establish the efficacy of scanning electron microscopy (SEM) and thermal ionisation mass spectrometry (TIMS) for the particle and bulk characterisation, respectively, of actinides on samples taken from within a shielded cell. These measurements were supported by γ-spectrometry and α-spectrometry. 'Hotswipe' samples taken from within a shielded cell with a well-known recent history have been prepared for particle and bulk analysis. SEM has been used to characterise individual particles from the swipe samples and the results have been related to known cell activities. Samples were prepared for SEM using a simple procedure to minimise the potential for sample contamination. The method proved to be capable of identifying 1 μm particles that contained U, Pu, Pa and Np. The measurement of U/Pu ratios was limited to particles that contained >2% Pu in U by weight. TIMS, together with alpha spectrometry, has been used to determine the bulk actinide composition of the samples whilst gamma spectrometry has been used to determine the fission product composition. Further work to improve the potential of SEM, and also secondary ionisation mass spectrometry (SIMS), for the measurement of hotswipe samples has been proposed. (author)

  9. HAC and fission reactors

    International Nuclear Information System (INIS)

    Fujiwara, I.; Moriyama, H.; Tachikawa, E.

    1984-01-01

    In the fission process, newly formed fission products undergo hot atom reactions due to their energetic recoil and abnormal positive charge. The hot atom reactions of the fission products are usually accompanied by secondary effects such as radiation damage, especially in condensed phase. For reactor safety it is valuable to know the chemical behaviour and the release behaviour of these radioactive fission products. Here, the authors study the chemical behaviour and the release behaviour of the fission products from the viewpoint of hot atom chemistry (HAC). They analyze the experimental results concerning fission product behaviour with the help of the theories in HAC and other neighboring fields such as radiation chemistry. (Auth.)

  10. Tim Berners-Lee, World Wide Web inventor

    CERN Multimedia

    1998-01-01

    The "Internet, Web, What's next?" conference on 26 June 1998 at CERN: Tim Berners-Lee, inventor of the World Wide Web and Director of the W3C, explains how the Web came to be and gave his views on the future.

  11. Tim Berners-Lee: inventor de la World Wide Web

    OpenAIRE

    Universidad de Granada. Biblioteca

    2015-01-01

    El presente Cat??logo contiene la exposici??n organizada por la Biblioteca de la ETSIIT de la Universidad de Granada durante los meses de noviembre-diciembre de 2015 y titulada: "Tim Berners-Lee: inventor de la World Wide Web"

  12. Fission Research at IRMM

    Directory of Open Access Journals (Sweden)

    Al-Adili A.

    2010-03-01

    Full Text Available Fission Research at JRC-IRMM has a longstanding tradition. The present paper is discussing recent investigations of fission fragment properties of 238 U(n,f, 234 U(n,f, prompt neutron emission in fission of 252 Cf(SF as well as the prompt fission neutron spectrum of 235 U(n,f and is presenting the most important results.

  13. Alpha and fission autoradiography of uranium rods

    International Nuclear Information System (INIS)

    Copic, M.; Ilicj, R.; Najzher, M.; Rant, J.

    1977-01-01

    Macro and micro-distribution of uranium minerals in ore bodies are investigated by alpha autoradiography and by neutron induced fission autoradiography using LR 115 solid state track detector. Optimal conditions are determined experimentally for both methods and examples presented. For field applications the alpha autoradiography (author)

  14. Equilibrium fission model calculations

    International Nuclear Information System (INIS)

    Beckerman, M.; Blann, M.

    1976-01-01

    In order to aid in understanding the systematics of heavy ion fission and fission-like reactions in terms of the target-projectile system, bombarding energy and angular momentum, fission widths are calculated using an angular momentum dependent extension of the Bohr-Wheeler theory and particle emission widths using angular momentum coupling

  15. Distinct forms of mitochondrial TOM-TIM supercomplexes define signal-dependent states of preprotein sorting.

    Science.gov (United States)

    Chacinska, Agnieszka; van der Laan, Martin; Mehnert, Carola S; Guiard, Bernard; Mick, David U; Hutu, Dana P; Truscott, Kaye N; Wiedemann, Nils; Meisinger, Chris; Pfanner, Nikolaus; Rehling, Peter

    2010-01-01

    Mitochondrial import of cleavable preproteins occurs at translocation contact sites, where the translocase of the outer membrane (TOM) associates with the presequence translocase of the inner membrane (TIM23) in a supercomplex. Different views exist on the mechanism of how TIM23 mediates preprotein sorting to either the matrix or inner membrane. On the one hand, two TIM23 forms were proposed, a matrix transport form containing the presequence translocase-associated motor (PAM; TIM23-PAM) and a sorting form containing Tim21 (TIM23(SORT)). On the other hand, it was reported that TIM23 and PAM are permanently associated in a single-entity translocase. We have accumulated distinct transport intermediates of preproteins to analyze the translocases in their active, preprotein-carrying state. We identified two different forms of active TOM-TIM23 supercomplexes, TOM-TIM23(SORT) and TOM-TIM23-PAM. These two supercomplexes do not represent separate pathways but are in dynamic exchange during preprotein translocation and sorting. Depending on the signals of the preproteins, switches between the different forms of supercomplex and TIM23 are required for the completion of preprotein import.

  16. Preliminary crystallographic studies of yeast mitochondrial peripheral membrane protein Tim44p

    Energy Technology Data Exchange (ETDEWEB)

    Josyula, Ratnakar [Department of Cell Biology, Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham (United States); Jin, Zhongmin [SER-CAT, APS, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); McCombs, Deborah; DeLucas, Lawrence [Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham (United States); Sha, Bingdong, E-mail: bdsha@uab.edu [Department of Cell Biology, Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham (United States)

    2006-02-01

    Tim44p is an essential mitochondrial peripheral membrane protein. To investigate the mechanism by which Tim44p functions in the TIM23 translocon to deliver the mitochondrial protein precursors, the yeast Tim44p has been crystallized. Protein translocations across mitochondrial membranes play critical roles in mitochondrion biogenesis. Protein transport from the cell cytosol to the mitochondrial matrix is carried out by the translocase of the outer membrane (TOM) complex and the translocase of the inner membrane (TIM) complexes. Tim44p is an essential mitochondrial peripheral membrane protein and a major component of the TIM23 translocon. To investigate the mechanism by which Tim44p functions in the TIM23 translocon to deliver the mitochondrial protein precursors, the yeast Tim44p was crystallized. The crystals diffract to 3.2 Å using a synchrotron X-ray source and belong to space group P6{sub 3}22, with unit-cell parameters a = 124.25, c = 77.83 Å. There is one Tim44p molecule in one asymmetric unit, which corresponds to a solvent content of approximately 43%. Structure determination by MAD methods is under way.

  17. Architecture of the TIM23 inner mitochondrial translocon and interactions with the matrix import motor.

    Science.gov (United States)

    Ting, See-Yeun; Schilke, Brenda A; Hayashi, Masaya; Craig, Elizabeth A

    2014-10-10

    Translocation of proteins from the cytosol across the mitochondrial inner membrane is driven by action of the matrix-localized multi-subunit import motor, which is associated with the TIM23 translocon. The architecture of the import apparatus is not well understood. Here, we report results of site-specific in vivo photocross-linking along with genetic and coimmunoprecipitation analyses dissecting interactions between import motor subunits and the translocon. The translocon is composed of the two integral membrane proteins Tim23 and Tim17, each containing four membrane-spanning segments. We found that Tim23 having a photoactivatable cross-linker in the matrix exposed loop between transmembrane domains 1 and 2 (loop 1) cross-linked to Tim44. Alterations in this loop destabilized interaction of Tim44 with the translocon. Analogously, Tim17 having a photoactivatable cross-linker in the matrix exposed loop between transmembrane segments 1 and 2 (loop 1) cross-linked to Pam17. Alterations in this loop caused destabilization of the interaction of Pam17 with the translocon. Substitution of individual photoactivatable residues in Tim44 and Pam17 in regions we previously identified as important for translocon association resulted in cross-linking to Tim23 and Tim17, respectively. Our results are consistent with a model in which motor association is achieved via interaction of Tim23 with Tim44, which serves as a scaffold for association of other motor components, and of Tim17 with Pam17. As both Tim44 and Pam17 have been implicated as regulatory subunits of the motor, this positioning is conducive for responding to conformational changes in the translocon upon a translocating polypeptide entering the channel. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Economist Innovation Award for Tim Berners-Lee

    CERN Multimedia

    2003-01-01

    In September, Tim Berners-Lee, who invented the World Wide Web at CERN and is now Director of the W3C World Wide Web Consortium, received the 2nd Economist Annual Innovation Award in Computing. With the award The Economist, a British weekly newspaper, recognises individuals responsible for breakthroughs in Bioscience, Computing, Energy and the Environment, and Telecommunications that have a profound impact on industry. A fifth award is given in a special "No Boundaries" category, observing innovation that transcends industries. Candidates for the awards are proposed by The Economist readers and writers, and by a group of judges. Tim Berners-Lee received the Computing award for his global hypertext project, to be known as the World Wide Web, which "forever altered the way information is shared" and is a huge contribution to the efficiency of the scientific community. Based on a programme for storing information using random associations called "Enquire", it...

  19. Fission level densities

    International Nuclear Information System (INIS)

    Maslov, V.M.

    1998-01-01

    Fission level densities (or fissioning nucleus level densities at fission saddle deformations) are required for statistical model calculations of actinide fission cross sections. Back-shifted Fermi-Gas Model, Constant Temperature Model and Generalized Superfluid Model (GSM) are widely used for the description of level densities at stable deformations. These models provide approximately identical level density description at excitations close to the neutron binding energy. It is at low excitation energies that they are discrepant, while this energy region is crucial for fission cross section calculations. A drawback of back-shifted Fermi gas model and traditional constant temperature model approaches is that it is difficult to include in a consistent way pair correlations, collective effects and shell effects. Pair, shell and collective properties of nucleus do not reduce just to the renormalization of level density parameter a, but influence the energy dependence of level densities. These effects turn out to be important because they seem to depend upon deformation of either equilibrium or saddle-point. These effects are easily introduced within GSM approach. Fission barriers are another key ingredients involved in the fission cross section calculations. Fission level density and barrier parameters are strongly interdependent. This is the reason for including fission barrier parameters along with the fission level densities in the Starter File. The recommended file is maslov.dat - fission barrier parameters. Recent version of actinide fission barrier data obtained in Obninsk (obninsk.dat) should only be considered as a guide for selection of initial parameters. These data are included in the Starter File, together with the fission barrier parameters recommended by CNDC (beijing.dat), for completeness. (author)

  20. Influence of inherited structures on the growth of basement-cored ranges, basin inversion and foreland basin development in the Central Andes, from apatite fission-track and apatite Helium thermochronology.

    Science.gov (United States)

    Zapata, S.; Sobel, E. R.; Del Papa, C.; Jelinek, A. R.; Muruaga, C.

    2017-12-01

    The Central Andes in NW of Argentina is part of a long-lived subduction zone, active since the Paleozoic. This region experienced several tectonic cycles; each of which created an unique set of structures and may have reactivated preexisting structures. These inherited structures may exert a first-order control over the different foreland deformational styles observed along the strike in the Central Andes. Our study area is located between 26°S and 28°S on the transition between the broken foreland (Santa Barbara system), which expresses a combination of thin-skin and thick-skin styles, and the Sierras Pampeanas, which is deform in a thick-skin style. The Cumbres Calchaquies range and the associated Choromoro Basin are located in the northern part of the study area, and are the southern expression of the Santa Barbara system. Published thermochronology data suggest that the rocks from the basement experienced Late Cretaceous and Late Miocene exhumation; the associated sedimentary rocks within the Choromoro basin experienced Paleogene and Late Miocene deformational phases. In contrast, the Sierra Aconquija range, located immediately south on the transition to the Sierras Pampeanas (thick skin) foreland basin, exhibit larger amounts of Miocene exhumation and lack of Cretaceous exhumation; the associated sedimentary rocks from the Tucuman basin have not been deformed since the Cretaceous. Our goal is to understand the evolution of the structural blocks and the structures responsible for the along strike changes in foreland basin deformational styles and their relation with inherited structures from previous tectonic cycles. We are obtaining new apatite U-Th/He and fission track data to reconstruct the thermal history of the basement, accompanied by U-Pb geochronology and stratigraphy to constrain the evolution of the associated sedimentary basins. Preliminary results combined with published data suggest that inherited structures within the study area have evolved

  1. New Constraints for Tectono-Thermal Alpine Evolution of the Pyrenees: Combining Zircon Fission-Track and (U-Th)/He Analyses with Raman Spectrometry and In-Situ K-Ar Geochronology

    Science.gov (United States)

    Waldner, M.; Bellahsen, N.; Mouthereau, F.; Pik, R.; Bernet, M.; Scaillet, S.; Rosenberg, C.

    2017-12-01

    The pyrenean range was formed by the convergence of European and Iberian plates following the inversion of the Mesozoic rifting in the north of Pyrenees. In the Axial Zone, the collision caused an antiformal nappe-stacking of tectonic units. Recent studies pointed out the importance of pre-collision structural and thermal inheritance that may play a major role for orogeny such as: 1) Paleozoic Variscan inheritance; 2) Mesozoic rift-related high geothermal gradients, which are maintained during the onset of convergence in the North Pyrenean Zone. From a mineralogical point of view, pre-collision feldspars have been destabilized and influenced the development of alpine phyllonite in brittle-ductile conditions which suggests a weak crustal behavior during the formation of the orogenic wedge. Our aim is to get a better understanding of alpine deformation and exhumation by coupling different thermochronological, geochronological and thermometric methods. We document the thermal evolution of each tectonic unit by using low-temperature thermochronometers (Zircon Fission Tracks, U-Th/He on zircons including laser ablation profiles). Our data on vertical profiles combined to existing dataset on apatite allows to model alpine exhumation across the Axial zone. Structural observations through alpine thrusts coupled to geochronology (in situ K/Ar on phengites), Raman and chlorite-phengite thermo(baro)metry provide new key data to unravel the alpine evolution of the Pyrenees. According to preliminary ZFT results on granite massifs in the central part of Pyrenean Axial zone (near ECORS profile), exhumation ages potentially indicates a migration of exhumation towards the south. Exhumation ages of the northern massifs seems to have preserved the North Pyrenean Cretaceous rift evolution. Further south, the onset of exhumation is as old as Paleocene, which precedes the Eocene ages of the literature. The low burial estimated in the northern massifs may indicate a high thermal gradient

  2. Determination of the effective range of fission fragments in UO2 and of the disintegration constant for the spontaneous fission of Uranium 238

    International Nuclear Information System (INIS)

    Spaggiari, E.R.V.

    1980-01-01

    Results are presented of measurements realized aiming to determine the disintegration constant of spontaneous fission of U-238, with a discussion of the method utilized in the detection of fission tracks in muscovite. Several blades of mica were placed between two cylinders of Uo 2 to be irradiated with the fragments of spontaneous fission of U-238, and the fission tracks duly enlarged after a convenient chemical action were observed with a projection optical microscope. The effective thickness of UO 2 contributing to the observed tracks was measured through the irradiation of mica samples juxtaposed to the UO 2 cylinder, with 14,0 MeV neutrons from the (d,t 2 ) reaction. The detection efficiency of fission tracks originated in that thickness is practically 100% [pt

  3. Dr TIM: Ray-tracer TIM, with additional specialist scientific capabilities

    Science.gov (United States)

    Oxburgh, Stephen; Tyc, Tomáš; Courtial, Johannes

    2014-03-01

    We describe several extensions to TIM, a raytracing program for ray-optics research. These include relativistic raytracing; simulation of the external appearance of Eaton lenses, Luneburg lenses and generalised focusing gradient-index lens (GGRIN) lenses, which are types of perfect imaging devices; raytracing through interfaces between spaces with different optical metrics; and refraction with generalised confocal lenslet arrays, which are particularly versatile METATOYs. Catalogue identifier: AEKY_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKY_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licencing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 106905 No. of bytes in distributed program, including test data, etc.: 6327715 Distribution format: tar.gz Programming language: Java. Computer: Any computer capable of running the Java Virtual Machine (JVM) 1.6. Operating system: Any, developed under Mac OS X Version 10.6 and 10.8.3. RAM: Typically 130 MB (interactive version running under Mac OS X Version 10.8.3) Classification: 14, 18. Catalogue identifier of previous version: AEKY_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183(2012)711 External routines: JAMA [1] (source code included) Does the new version supersede the previous version?: Yes Nature of problem: Visualisation of scenes that include scene objects that create wave-optically forbidden light-ray fields. Solution method: Ray tracing. Reasons for new version: Significant extension of the capabilities (see Summary of revisions), as demanded by our research. Summary of revisions: Added capabilities include the simulation of different types of camera moving at relativistic speeds relative to the scene; visualisation of the external appearance of generalised focusing gradient-index (GGRIN) lenses, including Maxwell fisheye, Eaton and Luneburg lenses; calculation of

  4. Fast fission phenomena

    International Nuclear Information System (INIS)

    Gregoire, Christian.

    1982-03-01

    Experimental studies of fast fission phenomena are presented. The paper is divided into three parts. In the first part, problems associated with fast fission processes are examined in terms of interaction potentials and a dynamic model is presented in which highly elastic collisions, the formation of compound nuclei and fast fission appear naturally. In the second part, a description is given of the experimental methods employed, the observations made and the preliminary interpretation of measurements suggesting the occurence of fast fission processes. In the third part, our dynamic model is incorporated in a general theory of the dissipative processes studied. This theory enables fluctuations associated with collective variables to be calculated. It is applied to highly inelastic collisions, to fast fission and to the fission dynamics of compound nuclei (for which a schematic representation is given). It is with these calculations that the main results of the second part can be interpreted [fr

  5. Role of the Phosphatidylserine Receptor TIM-1 in Enveloped-Virus Entry

    Science.gov (United States)

    Moller-Tank, Sven; Kondratowicz, Andrew S.; Davey, Robert A.; Rennert, Paul D.

    2013-01-01

    The cell surface receptor T cell immunoglobulin mucin domain 1 (TIM-1) dramatically enhances filovirus infection of epithelial cells. Here, we showed that key phosphatidylserine (PtdSer) binding residues of the TIM-1 IgV domain are critical for Ebola virus (EBOV) entry through direct interaction with PtdSer on the viral envelope. PtdSer liposomes but not phosphatidylcholine liposomes competed with TIM-1 for EBOV pseudovirion binding and transduction. Further, annexin V (AnxV) substituted for the TIM-1 IgV domain, supporting a PtdSer-dependent mechanism. Our findings suggest that TIM-1-dependent uptake of EBOV occurs by apoptotic mimicry. Additionally, TIM-1 enhanced infection of a wide range of enveloped viruses, including alphaviruses and a baculovirus. As further evidence of the critical role of enveloped-virion-associated PtdSer in TIM-1-mediated uptake, TIM-1 enhanced internalization of pseudovirions and virus-like proteins (VLPs) lacking a glycoprotein, providing evidence that TIM-1 and PtdSer-binding receptors can mediate virus uptake independent of a glycoprotein. These results provide evidence for a broad role of TIM-1 as a PtdSer-binding receptor that mediates enveloped-virus uptake. Utilization of PtdSer-binding receptors may explain the wide tropism of many of these viruses and provide new avenues for controlling their virulence. PMID:23698310

  6. TIM-family proteins promote infection of multiple enveloped viruses through virion-associated phosphatidylserine.

    Directory of Open Access Journals (Sweden)

    Stephanie Jemielity

    2013-03-01

    Full Text Available Human T-cell Immunoglobulin and Mucin-domain containing proteins (TIM1, 3, and 4 specifically bind phosphatidylserine (PS. TIM1 has been proposed to serve as a cellular receptor for hepatitis A virus and Ebola virus and as an entry factor for dengue virus. Here we show that TIM1 promotes infection of retroviruses and virus-like particles (VLPs pseudotyped with a range of viral entry proteins, in particular those from the filovirus, flavivirus, New World arenavirus and alphavirus families. TIM1 also robustly enhanced the infection of replication-competent viruses from the same families, including dengue, Tacaribe, Sindbis and Ross River viruses. All interactions between TIM1 and pseudoviruses or VLPs were PS-mediated, as demonstrated with liposome blocking and TIM1 mutagenesis experiments. In addition, other PS-binding proteins, such as Axl and TIM4, promoted infection similarly to TIM1. Finally, the blocking of PS receptors on macrophages inhibited the entry of Ebola VLPs, suggesting that PS receptors can contribute to infection in physiologically relevant cells. Notably, infection mediated by the entry proteins of Lassa fever virus, influenza A virus and SARS coronavirus was largely unaffected by TIM1 expression. Taken together our data show that TIM1 and related PS-binding proteins promote infection of diverse families of enveloped viruses, and may therefore be useful targets for broad-spectrum antiviral therapies.

  7. Fission product yields

    International Nuclear Information System (INIS)

    Valenta, V.; Hep, J.

    1978-01-01

    Data are summed up necessary for determining the yields of individual fission products from different fissionable nuclides. Fractional independent yields, cumulative and isobaric yields are presented here for the thermal fission of 235 U, 239 Pu, 241 Pu and for fast fission (approximately 1 MeV) of 235 U, 238 U, 239 Pu, 241 Pu; these values are included into the 5th version of the YIELDS library, supplementing the BIBFP library. A comparison is made of experimental data and possible improvements of calculational methods are suggested. (author)

  8. Fission neutron multiplicity calculations

    International Nuclear Information System (INIS)

    Maerten, H.; Ruben, A.; Seeliger, D.

    1991-01-01

    A model for calculating neutron multiplicities in nuclear fission is presented. It is based on the solution of the energy partition problem as function of mass asymmetry within a phenomenological approach including temperature-dependent microscopic energies. Nuclear structure effects on fragment de-excitation, which influence neutron multiplicities, are discussed. Temperature effects on microscopic energy play an important role in induced fission reactions. Calculated results are presented for various fission reactions induced by neutrons. Data cover the incident energy range 0-20 MeV, i.e. multiple chance fission is considered. (author). 28 refs, 13 figs

  9. Intermediate energy nuclear fission

    International Nuclear Information System (INIS)

    Hylten, G.

    1982-01-01

    Nuclear fission has been investigated with the double-kinetic-energy method using silicon surface barrier detectors. Fragment energy correlation measurements have been made for U, Th and Bi with bremsstrahlung of 600 MeV maximum energy. Distributions of kinetic energy as a function of fragment mass are presented. The results are compared with earlier photofission data and in the case of bismuth, with calculations based on the liquid drop model. The binary fission process in U, Yb, Tb, Ce, La, Sb, Ag and Y induced by 600 MeV protons has been investigated yielding fission cross sections, fragment kinetic energies, angular correlations and mass distributions. Fission-spallation competition calculations are used to deduce values of macroscopic fission barrier heights and nuclear level density parameter values at deformations corresponding to the saddle point shapes. We find macroscopic fission barriers lower than those predicted by macroscopic theories. No indication is found of the Businaro Gallone limit expected to occur somewhere in the mass range A = 100 to A = 140. For Ce and La asymmetric mass distributions similar to those in the actinide region are found. A method is described for the analysis of angular correlations between complementary fission products. The description is mainly concerned with fission induced by medium-energy protons but is applicable also to other projectiles and energies. It is shown that the momentum and excitation energy distributions of cascade residuals leading to fission can be extracted. (Author)

  10. Role of Tim50 in the transfer of precursor proteins from the outer to the inner membrane of mitochondria.

    Science.gov (United States)

    Mokranjac, Dejana; Sichting, Martin; Popov-Celeketić, Dusan; Mapa, Koyeli; Gevorkyan-Airapetov, Lada; Zohary, Keren; Hell, Kai; Azem, Abdussalam; Neupert, Walter

    2009-03-01

    Transport of essentially all matrix and a number of inner membrane proteins is governed, entirely or in part, by N-terminal presequences and requires a coordinated action of the translocases of outer and inner mitochondrial membranes (TOM and TIM23 complexes). Here, we have analyzed Tim50, a subunit of the TIM23 complex that is implicated in transfer of precursors from TOM to TIM23. Tim50 is recruited to the TIM23 complex via Tim23 in an interaction that is essentially independent of the rest of the translocase. We find Tim50 in close proximity to the intermembrane space side of the TOM complex where it recognizes both types of TIM23 substrates, those that are to be transported into the matrix and those destined to the inner membrane, suggesting that Tim50 recognizes presequences. This function of Tim50 depends on its association with TIM23. We conclude that the efficient transfer of precursors between TOM and TIM23 complexes requires the concerted action of Tim50 with Tim23.

  11. Fission studies of gold induced by (1665 MeV) π- using a CR-39 detector

    International Nuclear Information System (INIS)

    Muhammad Ikram Shahzad; Yasin, Zafar; Sher, Gul

    2012-01-01

    The fission cross section and fission probability of 197 Au, induced by (1665 MeV) π'-, have been studied using CR-39 track detectors. A 4π-geometry was used to count track statistics. A beam of negative pions of 1665 MeV was produced at AGS of Brookhaven National Laboratory, USA, and allowed to fall normally on the stack. Two detectors from the stack were scanned for fission fragment tracks after etching in 6N NaOH at 70 ℃. The statistics of fission fragment tracks in both detectors were obtained. It was found that there was a marked asymmetry of registered tracks with respect to the forward and backward hemispheres. This asymmetry could be partly accounted for on the basis of momentum transfer to the struck nucleus. On the basis of counting statistics fission cross section was measured, and fission probability was determined by dividing the fission cross section with the reaction cross section. The fission cross-section and fission probability were compared with the computed values using the cascade-exciton model code CEM95. (authors)

  12. Measurements of the effective range of fission fragments in UO2 and the disintegration constant for spontaneous fission of 238U

    International Nuclear Information System (INIS)

    Spaggiari, E.R.V.

    1978-01-01

    The results of measuments of the disintegration constant for spontaneous fission in 238 U are presented, with a discussion on the method used for the detection of fission tracks in muscovite mica. Samples of muscovite mica sandwiched between two natural uranium dioxide cylinders were irradiated with fragments of spontaneous fission and the etched tracks counted with projetion optical microscope. The effective thickness of the UO 2 layer which contributed to the observed tracks was measured through irradiation of mica samples, in contact with the UO 2 cylinder with 14,0 MeV neutrons from a (d,t) reaction. (Author) [pt

  13. Peripheral blood TIM-3 positive NK and CD8+ T cells throughout pregnancy

    DEFF Research Database (Denmark)

    Meggyes, Matyas; Miko, Eva; Polgar, Beata

    2014-01-01

    PROBLEM: The T-cell immunoglobulin and mucin domain (TIM) family is a relatively newly described group of molecules with a conserved structure and important immunological functions. Identification of Galectin-9 as a ligand for TIM-3 has established the Galectin-9/TIM-3 pathway as an important...... negative regulator of Th1 immunity and tolerance induction. Data about the TIM-3/Gal-9 pathway in the pathogenesis of human diseases is emerging, but their possible role during human pregnancy is not precisely known. The aim of our study was to investigate the number, phenotype and functional activity...... of TIM-3+ peripheral blood mononuclear cells during healthy human pregnancy. METHODS OF STUDY: 57 healthy pregnant women [first trimester (n = 16); second trimester (n = 19); third trimester (n = 22)] and 30 non-pregnant controls were enrolled in the study. We measured the surface expression of TIM-3...

  14. The nuclear fission

    International Nuclear Information System (INIS)

    Fiorentino, J.

    1983-01-01

    The nuclear fission process considering initially the formation of compound nucleus and finishing with radioactive decay of fission products is studied. The process is divided in three parts which consist of the events associated to the nucleus of intermediate transitional state, the scission configuration, and the phenomenum of post scission. (M.C.K.) [pt

  15. Fission gas detection system

    International Nuclear Information System (INIS)

    Colburn, R.P.

    1984-01-01

    A device for collecting fission gas released by failed fuel rods which device uses a filter adapted to pass coolant but to block passage of fission gas bubbles due to the surface tension of the bubbles. The coolant may be liquid metal. (author)

  16. Muon-induced fission

    International Nuclear Information System (INIS)

    Polikanov, S.

    1980-01-01

    A review of recent experimental results on negative-muon-induced fission, both of 238 U and 232 Th, is given. Some conclusions drawn by the author are concerned with muonic atoms of fission fragments and muonic atoms of the shape isomer of 238 U. (author)

  17. Relativistic Coulomb Fission

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Nuclear fission reactions induced by the electromagnetic field of relativistic nuclei are studied for energies relevant to present and future relativistic heavy ion accelerators. Cross sections are calculated for U-238 and Pu-239 fission induced by C-12, Si-28, Au-197, and U-238 projectiles. It is found that some of the cross sections can exceed 10 b.

  18. Study of hypernuclei fission

    International Nuclear Information System (INIS)

    Malek, F.

    1990-01-01

    This work is about PS177 experience made on LEAR machine at CERN in 1988. The annihilation reaction of anti protons on a target of Bismuth or Uranium is studied. Lambda particles are produced by this reaction, in the nucleus in 2% of cases 7.1 10 -3 hypernuclei by stopped antiproton in the target are produced. The prompt hypernucleus fission probability of uranium is 75% and that of Bismuth 10%. The mass distribution of fission fragments is symmetrical ((≡ the excitation energy of the nucleus is very high). If the nucleus hasn't fissioned, the non-mesonic lambda decay, gives it an energy of 100 MeV, what allows to fission later. This fission is delayed because the hypernucleus lifetime is 1.3 +0.25 -0.21 10 -10 sec for Bismuth [fr

  19. The nuclear fission process

    International Nuclear Information System (INIS)

    Wagemans, C.

    1991-01-01

    Fifty years after its discovery, the nuclear fission phenomenon is of recurring interest. When its fundamental physics aspects are considered, fission is viewed in a very positive way, which is reflected in the great interest generated by the meetings and large conferences organized for the 50th anniversary of its discovery. From a purely scientific and practical point of view, a new book devoted to the (low energy) nuclear fission phenomenon was highly desirable considering the tremendous amount of new results obtained since the publication of the book Nuclear Fission by Vandenbosch and Huizenga in 1973 (Academic Press). These new results could be obtained thanks to the growth of technology, which enabled the construction of powerful new neutron sources, particle and heavy ion accelerators, and very performant data-acquisition and computer systems. The re-invention of the ionization chamber, the development of large fission fragment spectrometers and sophisticated multiparameter devices, and the production of exotic isotopes also contributed significantly to an improved understanding of nuclear fission. This book is written at a level to introduce graduate students to the exciting subject of nuclear fission. The very complete list of references following each chapter also makes the book very useful for scientists, especially nuclear physicists. The book has 12 chapters covering the fission barrier and the various processes leading to fission as well as the characteristics of the various fission reaction products. In order to guarantee adequate treatment of the very specialized research fields covered, several distinguished scientists actively involved in some of these fields were invited to contribute their expertise as authors or co-authors of the different chapters

  20. Cooperation of TOM and TIM23 complexes during translocation of proteins into mitochondria.

    Science.gov (United States)

    Waegemann, Karin; Popov-Čeleketić, Dušan; Neupert, Walter; Azem, Abdussalam; Mokranjac, Dejana

    2015-03-13

    Translocation of the majority of mitochondrial proteins from the cytosol into mitochondria requires the cooperation of TOM and TIM23 complexes in the outer and inner mitochondrial membranes. The molecular mechanisms underlying this cooperation remain largely unknown. Here, we present biochemical and genetic evidence that at least two contacts from the side of the TIM23 complex play an important role in TOM-TIM23 cooperation in vivo. Tim50, likely through its very C-terminal segment, interacts with Tom22. This interaction is stimulated by translocating proteins and is independent of any other TOM-TIM23 contact known so far. Furthermore, the exposure of Tim23 on the mitochondrial surface depends not only on its interaction with Tim50 but also on the dynamics of the TOM complex. Destabilization of the individual contacts reduces the efficiency of import of proteins into mitochondria and destabilization of both contacts simultaneously is not tolerated by yeast cells. We conclude that an intricate and coordinated network of protein-protein interactions involving primarily Tim50 and also Tim23 is required for efficient translocation of proteins across both mitochondrial membranes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Detrital-zircon fission-track geochronology of the Lower Cenozoic sediments, NW Himalayan foreland basin: Clues for exhumation and denudation of the Himalaya during the India-Asia collision

    Science.gov (United States)

    Jain, A.; Lal, N.; Suelmani, B.; Awasthi, A. K.; Singh, S.; Kumar, R.

    2007-12-01

    Detrital-zircon fission-track geochronology of the synorogenically-deposited Subathu-Dagshai-Kasauli-Lower Siwalik Formations of the Sub-Himalayan Lower Cenozoic foreland basin reflects progressive effects of the Himalayan tectonometamorphic events on the Proterozoic-Paleozoic source rock as a consequence of the India-Asia collision. The oldest transgressive marine Subathu Formation (57.0-41.5 Ma) contains a very dominant 302.4 ± 21.9 Ma old detrital zircon FT suite with a few determinable 520.0 Ma grains. This old suite was derived by mild erosion of the Zircon Partially Annealed Zone (ZPAZ) of 240-180 oC, which affected the Himalayan Proterozoic basement and its Tethyan sedimentary cover as a consequence of first imprint of the collision. In addition, 50.0 Ma old detrital zircons in this formation were derived possibly from the Indus Tsangpo Suture Zone and the Trans-Himalayan Ladakh Batholith. Sudden source rock changes and unroofing are manifested in the overlying fluvial Dagshai (~30-20 Ma) and Kasauli (20-13 Ma) molassic sediments, which are characterised by dominant 30.0 and 25.0 Ma old youngest zircon FT peaks, respectively. A distinct unconformity spanning for about 10 Myr gets established between the Subathu-Dagshai formations on the basis of detrital- zircon FT ages. Molassic sedimentation since ~30 Ma coincides with the depletion of detritus from the suture zone, and the bulk derivation from the main Higher Himalayan source rock, which has undergone sequentially the UHP-HP-amphibolite facies metamorphism (53-40 Ma) in the extreme north and widespread Eo- and Neo-Himalayan tectonothermal events in the middle. Strength of the Pre-Himalayan Peaks (PHP) >50 Ma in these younger sediments gradually decreases with the intensification of the Himalayan thermal events till the end of the Kasauli sedimentation. Widespread Eo- and Neo-Himalayan metamorphic events (40.0-30.0 and 25.0-15.0 Ma) have almost remobilised the provenance and obliterated most of the

  2. Infrared spectroscopy for geologic interpretation of TIMS data

    Science.gov (United States)

    Bartholomew, Mary Jane

    1986-01-01

    The Portable Field Emission Spectrometer (PFES) was designed to collect meaningful spectra in the field under climatic, thermal, and sky conditions that approximate those at the time of the overflight. The specifications and procedures of PFES are discussed. Laboratory reflectance measurements of rocks and minerals were examined for the purpose of interpreting Thermal Infrared Multispectral Scanner (TIMS) data. The capability is currently being developed to perform direct laboratory measurement of the normal spectral radiance of Earth surface materials at low temperatures (20 to 30 C) at the Jet Propulsion Laboratory.

  3. Fission 2009 4. International Workshop on Nuclear Fission and Fission Product Spectroscopy - Compilation of slides

    International Nuclear Information System (INIS)

    2009-01-01

    This conference is dedicated to the last achievements in experimental and theoretical aspects of the nuclear fission process. The topics include: mass, charge and energy distribution, dynamical aspect of the fission process, nuclear data evaluation, quasi-fission and fission lifetime in super heavy elements, fission fragment spectroscopy, cross-section and fission barrier, and neutron and gamma emission. This document gathers the program of the conference and the slides of the presentations

  4. Fission/milligram of 235U in BIG-10 Tests A, C, E, and B

    International Nuclear Information System (INIS)

    Gilliam, D.M.; Grundl, J.A.; Hansen, G.E.

    1976-01-01

    The entire series of dosimetry foil tests at BIG-10 (including the preliminary Test A, five fission foil set irradiations--Tests C, five non-fission foil set irradiations--Tests E, and five track-etch detector irradiations--Tests B) were monitored continuously by the NBS double fission chamber PP5 in the central test cavity. The accuracy of the absolute fission counting data (fissions/milligram of 235 U) is estimated to be 1.4% for Tests A, C, and E and 1.5% for Test B. Deposit mass assay uncertainties remain the dominant error

  5. Tim-3 Up-regulation in Patients with Gastric Cancer and Peptic Ulcer Disease

    Science.gov (United States)

    Naghavi-Alhosseini, Mahdieh; Tehrani, Mohsen; Ajami, Abolghasem; Rafiei, Alireza; Taghvaei, Tarang; Vahedi-Larijani, Laleh; Hossein-Nataj, Hadi; Asgarian-Omran, Hossein

    2017-01-01

    Background: T-cell immunoglobulin and mucin domain protein-3 (Tim-3), an inhibitory immunoregulatory receptor, has been recently implicated in tumor biology and tumor-associated immune suppression. In the present study, expression of Tim-3 was evaluated in gastric cancer (GC) and peptic ulcer disease (PUD) at both mRNA and protein levels. Methods: A total of 133 gastric tissue biopsies, comprising 43 from GC cases, 48 from PUD and 42 from non-ulcer dyspepsia (NUD) serving as controls were collected. Additionally, non-neoplastic adjacent tissue biopsies were also obtained from 6 patients with GC. Infection with Helicobacter pylori was determined by the rapid urease test for all participants and H&E staining was conducted for GC and PUD patients. Tim-3 relative mRNA expression was determined by SYBR Green based Real-Time PCR using β-actin as a reference gene. Tim-3 protein expression was also studied by immunohistochemistry in 7 GC, 7 PUD and 10 NUD tissue samples. Results: Tim-3 was expressed at higher levels in GC (p=0.030) and PUD (p=0.022) cases compared to he NUD group. Among paired samples obtained from gastric cancer patients, tumor tissues showed elevated Tim-3 expression (p=0.019) in comparison with adjacent non-neoplastic biopsies. Tim-3 mRNA findings were supported by detection of more Tim-3 protein in cancerous (p=0.002) and ulcerative (p=0.01) tissues than in controls. Tim-3 was similarly expressed in H. pylori positive and negative cases. Conclusion: Higher Tim-3 expression in patients with gastric cancer and peptic ulcer implies that it might be involved in immune regulation and establishment of these gastrointestinal diseases. Targeted immunotherapy by blocking of inhibitory receptors like Tim-3 could be a promising approach for gastric cancer treatment. PMID:28441784

  6. Alkaline glass as induced fission fragment detectors

    International Nuclear Information System (INIS)

    Amorim, A.M.M.

    1986-01-01

    The slide glass, registered trade marks INLAB, INVICT and PERFECTA were compared. For the three kinds of glasses the following studies were done: chemical composition; general dissolution rate for hydrofluoric acid solutions of concentrations between 1 and 10M, at 30 0 C and ultrasound shaking; relative efficiency for recording fission fragment tracks from 252 Cf. The INLAB glass was selected due to the better quality of its surface after chemical etching. The HF concentration 2.5M was determined for chemical etching of INLAB glass, and the optimum etching time was chosen between 8 and 10 minutes. The thermal attenuation of latent tracks in the environmental temperature was observed for intervals uo to 31 days between the detector exposure to the fission fragment source and etching of tracks. Several methods were used for determining the detector parameters, such as: critical angle, angle of the cone and efficiency of etching. The effects of gamma irradiation from 60 Co and reactor neutrons in material properties as track detector were studied. Attenuation of latent tracks and saturation of color centers were observed for doses over 100M Rad. Since this kind of material contains uranium as impurity, uniformely distributed, slide glass were calibrated to be applied as a monitor of thermal neutron flux in nuclear reactor. (Author) [pt

  7. Cultura digital jovem: as TIMS invadem as periferias, e agora?

    Directory of Open Access Journals (Sweden)

    Márcia Gonçalves Nogueira

    2014-08-01

    Full Text Available Objective of this work is to present a literature review on Young and the Digital Cultural transformations caused by the dissemination of Information Technology and Communication Mobile and wireless (TIMS on the outskirts of the metropolitan area of Recife. To this end, we seek to identify how young periphery, high school students of a public school, they experience the Digital Culture in different social spaces; among them the school, scene of many tensions and generational conflicts and language as social and cultural use of these mobile devices. We highlight some theoretical approaches to the phenomenon of mobile communication and the concept of Digital Culture, adopted in this work. Proposing a reflection on the role of school in the current social context of constant cultural and linguistic transformations multimodality of the digital age. Finally, we present an exercise of looking on Youth Cultures, from different theoretical, to better understand the multiple transits covered by surveyed youth to express themselves and make sense of their audiovisual productions, mediated by TIMS. This theoretical argument was used in the dissertation in mathematics education and technology by one of the authors of this article. Therefore, we hope to contribute to further research on Digital Youth Culture in the context of the periphery.

  8. “This is you”: Encountering Shakespeare with Tim Crouch

    Directory of Open Access Journals (Sweden)

    Sara Soncini

    2017-11-01

    Full Text Available This essay considers Tim Crouch's "I Shakespeare", a suite of monologue plays based on "The Tempest" ("I, Caliban", 2003, "A Midsummer Night's Dream" ("I, Peaseblossom", 2004, "Macbeth" ("I, Banquo", 2005, "Twelfth Night" ("I, Malvolio", 2010 and "Julius Caesar" ("I, Cinna (the poet", 2012. While originally designed for a young audience, Crouch's adaptations have been performed in a variety of theatrical contexts that have added new and probably unforeseen dimensions to their negotiations with Shakespeare. In my analysis I turn to the notion of mobility as a key analytical tool to elucidate the method, aims, as well as the broader cultural meaning of Tim Crouch's reworkings. In his hands, Shakespeare is mobilized as a powerful resource to activate spectators and emphasize their co-authorship in the process of theatre. Through a combination of textual strategies and performance methods, the monologues construct the identities of Shakespeare's characters as multiple and mutable and, in parallel, cast their addressees in fluid, often contradictory roles. My main line of argument is that the plays' propensity of motion is rooted in their emphasis on Shakespeare as a highly mobile cultural signifier which seems confirmed by the monologues' journeys outside the UK. The further adaptational practices triggered by these encounters with foreign audiences are testament to the flexibility of Crouch's dramaturgy of process and its aptitude to accommodate new discursive identities and adjust to each new context of reception.

  9. U-series dating using thermal ionisation mass spectrometry (TIMS)

    International Nuclear Information System (INIS)

    McCulloch, M.T.

    1999-01-01

    U-series dating is based on the decay of the two long-lived isotopes 238 U(τ 1/2 =4.47 x 10 9 years) and 235 U (τ 1/2 0.7 x 10 9 years). 238 U and its intermediate daughter isotopes 234 U (τ 1/2 = 245.4 ka) and 230 Th (τ 1/2 = 75.4 ka) have been the main focus of recently developed mass spectrometric techniques (Edwards et al., 1987) while the other less frequently used decay chain is based on the decay 235 U to 231 Pa (τ 1/2 = 32.8 ka). Both the 238 U and 235 U decay chains terminate at the stable isotopes 206 Pb and 207 Pb respectively. Thermal ionization mass spectrometry (TIMS) has a number of inherent advantages, mainly the ability to measure isotopic ratios at high precision on relatively small samples. In spite of these now obvious advantages, it is only since the mid-1980's when Chen et al., (1986) made the first precise measurements of 234 U and 232 Th in seawater followed by Edwards et al., (1987) who made combined 234 U- 230 Th measurements, was the full potential of mass spectrometric methods first realised. Several examples are given to illustrate various aspects of TIMS U-series

  10. Space Solar Power Technical Interchange Meeting 2: SSP TIM 2

    Science.gov (United States)

    Sanders, Jim; Hawk, Clark W.

    1998-01-01

    The 2nd Space Solar Power Technical Interchange Meeting (SSP TIM 2) was conducted September 21st through 24th with the first part consisting of a Plenary session. The summary results of this Plenary session are contained in part one of this report. The attendees were then organized into Working Breakout Sessions and Integrated Product Team (IPT) Sessions for the purpose of conducting in-depth discussions in specific topic areas and developing a consensus as to appropriate study plans and actions to be taken. The Second part covers the Plenary Summary Session, which contains the summary results of the Working Breakout Sessions and IPT Sessions. The appendix contains the list of attendees. The ob'jective was to provide an update for the study teams and develop plans for subsequent study activities. This SSP TIM 2 was initiated and the results reported electronically over the Internet. The International Space Station (ISS) could provide the following opportunities for conducting research and technology (R&T) which are applicable to SSP: (1) Automation and Robotics, (2) Advanced Power Generation, (3) Advanced Power Management & Distribution (PMAD), (4) Communications Systems and Networks, (5) Energy Storage, (6) In Space Propulsion (ISP), (7) Structural Dynamics and Control, and Assembly and (8) Wireless Power Transmission.

  11. Sild humanitaar- ja loodusteaduste vahel : intervjuu Aberdeeni ülikooli sotsiaalantropoloogia professori Tim Ingoldiga / Tim Ingold ; interv. Alo Joosepson, Kaie Kotov, Silver Rattasepp, Riste Keskpaik

    Index Scriptorium Estoniae

    Ingold, Tim

    2004-01-01

    4. rahvusvahelise keskkonnaesteetika ja -semiootika konverentsi "Kultuur, loodus, semiootika: kohad" üks peaesineja Tim Ingold tegeleb 1990-ndatest alates antropoloogia ja kunsti suhte uurimisega ning loeb kursust "Antropoloogia, arheoloogia, kunst ja arhitektuur"

  12. Fission in a Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-26

    A three-year theory project was undertaken to study the fission process in extreme astrophysical environments, such as the crust of neutron stars. In the first part of the project, the effect of electron screening on the fission process was explored using a microscopic approach. For the first time, these calculations were carried out to the breaking point of the nucleus. In the second part of the project, the population of the fissioning nucleus was calculated within the same microscopic framework. These types of calculations are extremely computer-intensive and have seldom been applied to heavy deformed nuclei, such as fissioning actinides. The results, tools and methodologies produced in this work will be of interest to both the basic-science and nuclear-data communities.

  13. Dysregulation of TIM-3-galectin-9 pathway in the cystic fibrosis airways.

    LENUS (Irish Health Repository)

    Vega-Carrascal, Isabel

    2012-02-01

    The T-cell Ig and mucin domain-containing molecules (TIMs) have emerged as promising therapeutic targets to correct abnormal immune function in several autoimmune and chronic inflammatory conditions. It has been reported that proinflammatory cytokine dysregulation and neutrophil-dominated inflammation are the main causes of morbidity in cystic fibrosis (CF). However, the role of TIM receptors in CF has not been investigated. In this study, we demonstrated that TIM-3 is constitutively overexpressed in the human CF airway, suggesting a link between CF transmembrane conductance regulator (CFTR) function and TIM-3 expression. Blockade of CFTR function with the CFTR inhibitor-172 induced an upregulation of TIM-3 and its ligand galectin-9 in normal bronchial epithelial cells. We also established that TIM-3 serves as a functional receptor in bronchial epithelial cells, and physiologically relevant concentrations of galectin-9 induced TIM-3 phosphorylation, resulting in increased IL-8 production. In addition, we have demonstrated that both TIM-3 and galectin-9 undergo rapid proteolytic degradation in the CF lung, primarily because of neutrophil elastase and proteinase-3 activity. Our results suggest a novel intrinsic defect that may contribute to the neutrophil-dominated immune response in the CF airways.

  14. Dysregulation of TIM-3-galectin-9 pathway in the cystic fibrosis airways.

    LENUS (Irish Health Repository)

    Vega-Carrascal, Isabel

    2011-03-01

    The T-cell Ig and mucin domain-containing molecules (TIMs) have emerged as promising therapeutic targets to correct abnormal immune function in several autoimmune and chronic inflammatory conditions. It has been reported that proinflammatory cytokine dysregulation and neutrophil-dominated inflammation are the main causes of morbidity in cystic fibrosis (CF). However, the role of TIM receptors in CF has not been investigated. In this study, we demonstrated that TIM-3 is constitutively overexpressed in the human CF airway, suggesting a link between CF transmembrane conductance regulator (CFTR) function and TIM-3 expression. Blockade of CFTR function with the CFTR inhibitor-172 induced an upregulation of TIM-3 and its ligand galectin-9 in normal bronchial epithelial cells. We also established that TIM-3 serves as a functional receptor in bronchial epithelial cells, and physiologically relevant concentrations of galectin-9 induced TIM-3 phosphorylation, resulting in increased IL-8 production. In addition, we have demonstrated that both TIM-3 and galectin-9 undergo rapid proteolytic degradation in the CF lung, primarily because of neutrophil elastase and proteinase-3 activity. Our results suggest a novel intrinsic defect that may contribute to the neutrophil-dominated immune response in the CF airways.

  15. Tim Berners-Lee at the RSIS conference from 8-9 December 2003.

    CERN Multimedia

    Patrice Loiez

    2003-01-01

    Tim Berners-Lee participated in the Role of Science in the Information Society conference held at CERN from 8-9 December 2003. Tim Berners-Lee developed the first network and server system that lead to the World Wide Web.

  16. Microscopic Theory of Fission

    International Nuclear Information System (INIS)

    Younes, W; Gogny, D

    2008-01-01

    In recent years, the microscopic method has been applied to the notoriously difficult problem of nuclear fission with unprecedented success. In this paper, we discuss some of the achievements and promise of the microscopic method, as embodied in the Hartree-Fock method using the Gogny finite-range effective interaction, and beyond-mean-field extensions to the theory. The nascent program to describe induced fission observables using this approach at the Lawrence Livermore National Laboratory is presented

  17. Fusion-fission dynamics

    International Nuclear Information System (INIS)

    Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

    1992-01-01

    Classical dynamical calculations of the heavy ion induced fission processes have been performed for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus. As a result prescission lifetimes were obtained and compared with the experimental values. The comparison between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. (orig.)

  18. A new technique to measure fission-product diffusion coefficients in UO2 fuel

    International Nuclear Information System (INIS)

    Hocking, W.H.; Verrall, R.A.; Bushby, S.J.

    1999-01-01

    This paper describes a new out-reactor technique for the measurement of fission-product diffusion rates in UO 2 . The technique accurately simulates in-reactor fission-fragment effects: a thermal diffusion that is due to localized mixing in the fission track, radiation-enhanced diffusion that is due to point-defect creation by fission fragments, and bubble resolution. The technique utilizes heavy-ion accelerators - low energy (40 keV to 1 MeV) for fission-product implantation, high energy (72 MeV) to create fission-fragment damage effects, and secondary ion mass spectrometry (SIMS) for measuring the depth profile of the implanted species. Preliminary results are presented from annealing tests (not in the 72 MeV ion flux) at 1465 deg. C and 1650 deg. C at low and high concentrations of fission products. (author)

  19. Photofission observations in reactor environments using selected fission-product yields

    International Nuclear Information System (INIS)

    Gold, R.; Ruddy, F.H.; Roberts, J.H.

    1982-01-01

    A new method for the observation of photofission in reactor environments is advanced. It is based on the in-situ observation of fission product yield. In fact, at a given in-situ reactor location, the fission product yield is simply a weighted linear combination of the photofission product yield, Y/sub gamma/, and the neutron induced fission product yield, Y/sub n. The weight factors arising in this linear combination are the photofission fraction and neutron induced fission fraction, respectively. This method can be readily implemented with established techniques for measuring in-situ reactor fission product yield. For example, one can use the method based on simultaneous irradiation of radiometric (RM) and solid state track recorder (SSTR) fission monitors. The sensitivity and accuracy and current knowledge of fission product yields. Unique advantages of this method for reactor applications are emphasized

  20. U-series dating using thermal ionisation mass spectrometry (TIMS)

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, M.T. [Australian National University, Canberra, ACT (Australia). Research School of Earth Science

    1999-11-01

    U-series dating is based on the decay of the two long-lived isotopes{sup 238}U({tau}{sub 1/2}=4.47 x 10{sup 9} years) and {sup 235}U ({tau}{sub 1/2} 0.7 x 10{sup 9} years). {sup 238}U and its intermediate daughter isotopes {sup 234}U ({tau}{sub 1/2} = 245.4 ka) and {sup 230}Th ({tau}{sub 1/2} = 75.4 ka) have been the main focus of recently developed mass spectrometric techniques (Edwards et al., 1987) while the other less frequently used decay chain is based on the decay {sup 235}U to {sup 231}Pa ({tau}{sub 1/2} = 32.8 ka). Both the {sup 238}U and {sup 235}U decay chains terminate at the stable isotopes {sup 206}Pb and {sup 207}Pb respectively. Thermal ionization mass spectrometry (TIMS) has a number of inherent advantages, mainly the ability to measure isotopic ratios at high precision on relatively small samples. In spite of these now obvious advantages, it is only since the mid-1980`s when Chen et al., (1986) made the first precise measurements of {sup 234}U and {sup 232}Th in seawater followed by Edwards et al., (1987) who made combined {sup 234}U-{sup 230}Th measurements, was the full potential of mass spectrometric methods first realised. Several examples are given to illustrate various aspects of TIMS U-series 9 refs., 3 figs.

  1. Potentials of fissioning plasmas

    International Nuclear Information System (INIS)

    Karlheinz, Thom.

    1979-01-01

    Successful experiments with the nuclear pumping of lasers have demonstrated that in gaseous medium the kinetic energy of fission fragments can be converted directly into non-equilibrium optical radiation. This confirms the concept that the fissioning medium in a gas-phase nuclear reactor shows an internal structure such as a plasma in nearly thermal equilibrium varying up to a state of extreme-non-equilibrium. The accompanying variations of temperatures, pressure and radiative spectrum suggest wide ranges of applications. For example, in the gas-phase fission reactor concept enriched uranium hexafluoride or an uranium plasma replaces conventional fuel elements and permits operation above the melting point of solid materials. This potential has been motivation for the US National Aeronautics and Space Administration (NASA) to conduct relevant research for high specific impulse propulsion in space. The need to separate the high temperature gaseous fuel from the surfaces of a containing vessel and to protect them against thermal radiation has led to the concept of an externally moderated reactor in which the fissioning gaseous material is suspended by fluid dynamic means and the flow of opaque buffer gas removes the power. The gaseous nuclear fuel can slowly be circulated through the reactor for continuous on-site reprocessing including the annihilation of transuranium actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides can thus be achieved. These characteristics and the unique radiative properties led to the expectation that the gas-phase fission reactor could feature improved safety, safeguarding and economy, in addition to new technologies such as processing, photochemistry and the transmission of power over large distances in space

  2. Traditional Indian medicine (TIM and traditional Korean medicine (TKM: aconstitutional-based concept and comparison

    Directory of Open Access Journals (Sweden)

    Young Min Kang

    2017-06-01

    Full Text Available Traditional and complementary medicine (T&CM plays an integral role in providing health care worldwide. It is based on sound fundamental principles and centuries of practices. This study compared traditional Indian medicine (TIM and traditional Korean medicine (TKM basing on data obtained from peer reviewed articles, respective government institutional reports and World Health Organization reports. Despite the fact that TIM and TKM have individual qualities that are unique from each other including different histories of origin, they share a lot in common. Apart from Homeopathy in TIM, both systems are hinged on similar principle of body constitutional-based concept and similar disease diagnosis methods of mainly auscultation, palpation, visual inspection, and interrogation. Similarly, the treatment methods of TIM and TKM follow similar patterns involving use of medicinal herbs, moxibustion, acupuncture, cupping, and manual therapy. Both T&CM are majorly practiced in well-established hospitals by T&CM doctors who have undergone an average of 6–7 years of specialized trainings. However, unlike TIM which has less insurance coverage, the popularity of TKM is majorly due to its wide national insurance coverage. These two medical traditions occupy increasingly greater portion of the global market. However, TIM especially Ayurveda has gained more global recognition than TKM although the emergence of Sasang Constitutional Medicine in TKM is beginning to become more popular. This comparative analysis between TIM and TKM may provide vital and insightful contribution towards constitutional-based concept for further development and future studies in T&CM.

  3. Traditional Indian medicine (TIM) and traditional Korean medicine (TKM): aconstitutional-based concept and comparison.

    Science.gov (United States)

    Kang, Young Min; Komakech, Richard; Karigar, Chandrakant Shivappa; Saqib, Asma

    2017-06-01

    Traditional and complementary medicine (T&CM) plays an integral role in providing health care worldwide. It is based on sound fundamental principles and centuries of practices. This study compared traditional Indian medicine (TIM) and traditional Korean medicine (TKM) basing on data obtained from peer reviewed articles, respective government institutional reports and World Health Organization reports. Despite the fact that TIM and TKM have individual qualities that are unique from each other including different histories of origin, they share a lot in common. Apart from Homeopathy in TIM, both systems are hinged on similar principle of body constitutional-based concept and similar disease diagnosis methods of mainly auscultation, palpation, visual inspection, and interrogation. Similarly, the treatment methods of TIM and TKM follow similar patterns involving use of medicinal herbs, moxibustion, acupuncture, cupping, and manual therapy. Both T&CM are majorly practiced in well-established hospitals by T&CM doctors who have undergone an average of 6-7 years of specialized trainings. However, unlike TIM which has less insurance coverage, the popularity of TKM is majorly due to its wide national insurance coverage. These two medical traditions occupy increasingly greater portion of the global market. However, TIM especially Ayurveda has gained more global recognition than TKM although the emergence of Sasang Constitutional Medicine in TKM is beginning to become more popular. This comparative analysis between TIM and TKM may provide vital and insightful contribution towards constitutional-based concept for further development and future studies in T&CM.

  4. Taming dendritic cells with TIM-3: another immunosuppressive strategy used by tumors.

    Science.gov (United States)

    Patel, Jaina; Bozeman, Erica N; Selvaraj, Periasamy

    2012-12-01

    Evaluation of: Chiba S, Baghdadi M, Akiba H et al. Tumor-infiltrating DCs suppress nucleic acid-mediated innate immune responses through interactions between the receptor TIM-3 and the alarmin HMGB1. Nat. Immunol. 13, 832-842 (2012). The identification of TIM-3 expression on tumor-associated dendritic cells (TADCs) provides insight into another aspect of tumor-mediated immunosuppression. The role of TIM-3 has been well characterized on tumor-infiltrating T cells; however, its role on TADCs was not previously known. The current paper demonstrated that TIM-3 was predominantly expressed by TADCs and its interaction with the nuclear protein HMGB1 suppressed nucleic acid-mediated activation of an effective antitumor immune response. The authors were able to show that TIM-3 interaction with HMGB1 prevented the localization of nucleic acids into endosomal vesicles. Furthermore, chemotherapy was found to be more effective in anti-TIM-3 monoclonal antibody-treated mice or mice depleted of all DCs, which indicated that a significant role is played by TADCs in inhibiting tumor regression. Taken together, these findings identify TIM-3 as a potential target for inducing antitumor immunity in conjunction with DNA vaccines and/or immunogenic chemotherapy in clinical settings.

  5. Airborne Thermal Infrared Multispectral Scanner (TIMS) images over disseminated gold deposits, Osgood Mountains, Humboldt County, Nevada

    Science.gov (United States)

    Krohn, M. Dennis

    1986-01-01

    The U.S. Geological Survey (USGS) acquired airborne Thermal Infrared Multispectral Scanner (TIMS) images over several disseminated gold deposits in northern Nevada in 1983. The aerial surveys were flown to determine whether TIMS data could depict jasperoids (siliceous replacement bodies) associated with the gold deposits. The TIMS data were collected over the Pinson and Getchell Mines in the Osgood Mountains, the Carlin, Maggie Creek, Bootstrap, and other mines in the Tuscarora Mountains, and the Jerritt Canyon Mine in the Independence Mountains. The TIMS data seem to be a useful supplement to conventional geochemical exploration for disseminated gold deposits in the western United States. Siliceous outcrops are readily separable in the TIMS image from other types of host rocks. Different forms of silicification are not readily separable, yet, due to limitations of spatial resolution and spectral dynamic range. Features associated with the disseminated gold deposits, such as the large intrusive bodies and fault structures, are also resolvable on TIMS data. Inclusion of high-resolution thermal inertia data would be a useful supplement to the TIMS data.

  6. The TIM Barrel Architecture Facilitated the Early Evolution of Protein-Mediated Metabolism.

    Science.gov (United States)

    Goldman, Aaron David; Beatty, Joshua T; Landweber, Laura F

    2016-01-01

    The triosephosphate isomerase (TIM) barrel protein fold is a structurally repetitive architecture that is present in approximately 10% of all enzymes. It is generally assumed that this ubiquity in modern proteomes reflects an essential historical role in early protein-mediated metabolism. Here, we provide quantitative and comparative analyses to support several hypotheses about the early importance of the TIM barrel architecture. An information theoretical analysis of protein structures supports the hypothesis that the TIM barrel architecture could arise more easily by duplication and recombination compared to other mixed α/β structures. We show that TIM barrel enzymes corresponding to the most taxonomically broad superfamilies also have the broadest range of functions, often aided by metal and nucleotide-derived cofactors that are thought to reflect an earlier stage of metabolic evolution. By comparison to other putatively ancient protein architectures, we find that the functional diversity of TIM barrel proteins cannot be explained simply by their antiquity. Instead, the breadth of TIM barrel functions can be explained, in part, by the incorporation of a broad range of cofactors, a trend that does not appear to be shared by proteins in general. These results support the hypothesis that the simple and functionally general TIM barrel architecture may have arisen early in the evolution of protein biosynthesis and provided an ideal scaffold to facilitate the metabolic transition from ribozymes, peptides, and geochemical catalysts to modern protein enzymes.

  7. Nuclear fission and neutron-induced fission cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.

    1981-01-01

    A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.

  8. Molecular mechanism for differential recognition of membrane phosphatidylserine by the immune regulatory receptor Tim4.

    Science.gov (United States)

    Tietjen, Gregory T; Gong, Zhiliang; Chen, Chiu-Hao; Vargas, Ernesto; Crooks, James E; Cao, Kathleen D; Heffern, Charles T R; Henderson, J Michael; Meron, Mati; Lin, Binhua; Roux, Benot; Schlossman, Mark L; Steck, Theodore L; Lee, Ka Yee C; Adams, Erin J

    2014-04-15

    Recognition of phosphatidylserine (PS) lipids exposed on the extracellular leaflet of plasma membranes is implicated in both apoptotic cell removal and immune regulation. The PS receptor T cell immunoglobulin and mucin-domain-containing molecule 4 (Tim4) regulates T-cell immunity via phagocytosis of both apoptotic (high PS exposure) and nonapoptotic (intermediate PS exposure) activated T cells. The latter population must be removed at lower efficiency to sensitively control immune tolerance and memory cell population size, but the molecular basis for how Tim4 achieves this sensitivity is unknown. Using a combination of interfacial X-ray scattering, molecular dynamics simulations, and membrane binding assays, we demonstrate how Tim4 recognizes PS in the context of a lipid bilayer. Our data reveal that in addition to the known Ca(2+)-coordinated, single-PS binding pocket, Tim4 has four weaker sites of potential ionic interactions with PS lipids. This organization makes Tim4 sensitive to PS surface concentration in a manner capable of supporting differential recognition on the basis of PS exposure level. The structurally homologous, but functionally distinct, Tim1 and Tim3 are significantly less sensitive to PS surface density, likely reflecting the differences in immunological function between the Tim proteins. These results establish the potential for lipid membrane parameters, such as PS surface density, to play a critical role in facilitating selective recognition of PS-exposing cells. Furthermore, our multidisciplinary approach overcomes the difficulties associated with characterizing dynamic protein/membrane systems to reveal the molecular mechanisms underlying Tim4's recognition properties, and thereby provides an approach capable of providing atomic-level detail to uncover the nuances of protein/membrane interactions.

  9. The evaluation for reference fission yield of 238U fission

    International Nuclear Information System (INIS)

    Liang Qichang; Liu Tingjin

    1998-01-01

    In the fission yield data evaluation and measurement, the reference yield is very important, good or poor recommended or measurement values depend upon the reference data to a great extent. According to the CRP's requirement, the evaluation of reference fission yields have been and will be carried out in CNDC, as a part of the whole work (contract No.9504/R 0 /Regular Budget Fund), the evaluation for 29 reference fission yields of 15 product nuclides from 238 U fission have been completed

  10. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  11. 60 years controlled nuclear fission: CP-1

    International Nuclear Information System (INIS)

    Anon.

    2002-01-01

    On December 2, 1942, the Chicago Pile 1 (CP-1) went critical for the first time. In this way, the scientists and engineers involved in the project under the leadership of Enrico Fermi succeeded in demonstrating that a self-sustaining nuclear reaction with nuclear fission processes was technically feasible. Only four years after the discovery and proof of nuclear fission by Otto Hahn, Fritz Strassmann, and Lise Meitner, the experiment consisting of graphite blocks as the moderator and uranium dioxide pellets as the fuel, as well as instrumentation and control devices, had been set up in the former squash court of the field and track stadium of the University of Chicago. Precisely at 3.36 a.m. Chicago time, after control rods had been withdrawn, the instruments showed the chain reaction by the neutron flux they indicated. An important cornerstone in the use of nuclear power had thus been laid. (orig.)

  12. Circulating and tumor-infiltrating Tim-3 in patients with colorectal cancer

    Science.gov (United States)

    Gao, Quanli; Yuan, Peng; Zhao, Peng; Yuan, Huijuan; Fan, Huijie; Li, Tiepeng; Qin, Peng; Han, Lu; Fang, Weijia; Suo, Zhenhe

    2015-01-01

    T-cell exhaustion represents a progressive loss of T-cell function. The inhibitory receptor PD-1 is known to negatively regulate CD8+ T cell responses directed against tumor antigen, but the blockades of PD-1 pathway didn't show the objective responses in patients with colorectal cancer (CRC). Thus, further exploring the molecular mechanism responsible for inducing T-cell dysfunction in CRC patients may reveal effective strategies for immune therapy. This study aims to characterize co-inhibitory receptors on T cells in CRC patients to identify novel targets for immunotherapy. In this study, peripheral blood samples from 20 healthy controls and 54 consented CRC patients, and tumor and matched paraneoplastic tissues from 7 patients with advanced CRC, subjected to multicolor flow cytometric analysis of the expression of PD-1 and Tim-3 receptors on CD8+ T cells. It was found that CRC patients presented with significantly higher levels of circulating Tim-3+PD-1+CD8+ T cells compared to the healthy controls (medians of 3.12% and 1.99%, respectively, p = 0.0403). A similar increase of Tim-3+PD-1+CD8+ T cells was also observed in the tumor tissues compared to paraneoplastic tussues. Tim-3+PD-1+CD8+ T cells in tumor tissues produced even less cytokine than that in paraneoplastic tissues. Functional ex vivo experiments showed that Tim-3+PD-1+CD8+ T cells produced significantly less IFN-γ than Tim-3−PD-1−CD8+ T cells, followed by Tim-3+PD-1−CD8+ T cells, and Tim-3−PD-1+CD8+ T cells, indicating a stronger inhibition of IFN-γ production of Tim-3+CD8+ T cells. It is also found in this study that Tim-3+PD-1+CD8+ T cell increase in circulation was correlated with clinical cancer stage but not histologic grade and serum concentrations of cancer biomarker CEA. Our results indicate that upregulation of the inhibitory receptor Tim-3 may restrict T cell responses in CRC patients, and therefore blockage of Tim-3 and thus restoring T cell responses may be a potential

  13. Fission product detection

    International Nuclear Information System (INIS)

    Liatard, E.; Akrouf, S.; Bruandet, J.F

    1987-01-01

    The response of photovoltaic cells to heavy ions and fission products have been tested on beam. Their main advantages are their extremely low price, their low sensitivity to energetic light ions with respect to fission products, and the possibility to cut and fit them together to any shape without dead zone. The time output signals of a charge sensitive preamplifier connected to these cells allows fast coincidences. A resolution of 12ns (F.W.H.M.) have been measured between two cells [fr

  14. Low energy nuclear fission

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1982-02-01

    In these lectures we present the liquid drop model of fission and compare some of its prediction with experiment. The liquid drop analogy allows to define in a rather simple and intuitive way a number of useful concepts and possible observables. We then discuss, using the example of the oscillator model, the generality of shell effects. We show how a synthesis of the liquid drop model and of the shell model can be made using the Strutinsky shell averaging procedure. Some experimental data related to the existence of shape isomers are presented and discussed. We conclude by discussing some aspects, both experimental and theoretical, of fission dynamics

  15. Fission of heavy hypernuclei

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1993-01-01

    The results on delayed and prompt fission of heavy hypernuclei obtained by the LEAR PS177 collaboration are recalled and discussed. It is shown that the hypernuclei life-times can be explained in term of a weak strangeness violating lambda-nucleon interaction with a cross section close to 6.0 10 -15 barns. The lambda attachment function is shown to be sensitive to the scission configuration, just before fission, and to the neck dynamics. This function provides a new way to study the nuclear scission process. (author)

  16. Fission gas measuring technology

    International Nuclear Information System (INIS)

    Lee, Hyung Kwon; Kim, Eun Ka; Hwang, Yong Hwa; Lee, Eun Pyo; Chun, Yong Bum; Seo, Ki Seog; Park, Dea Gyu; Chu, Yong Sun; Ahn, Sang Bok.

    1998-02-01

    Safety and economy of nuclear plant are greatly affected by the integrity of nuclear fuels during irradiation reactor core. A series of post-irradiation examination (PIE) including non-destructive and destructive test is to be conducted to evaluate and characterize the nuclear performance. In this report, a principle of the examination equipment to measure and analyse fission gases existing nuclear fuels were described and features of the component and device consisting the fission gas measuring equipment are investigated. (author). 4 refs., 2 tabs., 6 figs

  17. Fission gas measuring technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyung Kwon; Kim, Eun Ka; Hwang, Yong Hwa; Lee, Eun Pyo; Chun, Yong Bum; Seo, Ki Seog; Park, Dea Gyu; Chu, Yong Sun; Ahn, Sang Bok

    1998-02-01

    Safety and economy of nuclear plant are greatly affected by the integrity of nuclear fuels during irradiation reactor core. A series of post-irradiation examination (PIE) including non-destructive and destructive test is to be conducted to evaluate and characterize the nuclear performance. In this report, a principle of the examination equipment to measure and analyse fission gases existing nuclear fuels were described and features of the component and device consisting the fission gas measuring equipment are investigated. (author). 4 refs., 2 tabs., 6 figs.

  18. Fission modelling with FIFRELIN

    International Nuclear Information System (INIS)

    Litaize, Olivier; Serot, Olivier; Berge, Leonie

    2015-01-01

    The nuclear fission process gives rise to the formation of fission fragments and emission of particles (n,γ, e - ). The particle emission from fragments can be prompt and delayed. We present here the methods used in the FIFRELIN code, which simulates the prompt component of the de-excitation process. The methods are based on phenomenological models associated with macroscopic and/or microscopic ingredients. Input data can be provided by experiment as well as by theory. The fission fragment de-excitation can be performed within Weisskopf (uncoupled neutron and gamma emission) or a Hauser-Feshbach (coupled neutron/gamma emission) statistical theory. We usually consider five free parameters that cannot be provided by theory or experiments in order to describe the initial distributions required by the code. In a first step this set of parameters is chosen to reproduce a very limited set of target observables. In a second step we can increase the statistics to predict all other fission observables such as prompt neutron, gamma and conversion electron spectra but also their distributions as a function of any kind of parameters such as, for instance, the neutron, gamma and electron number distributions, the average prompt neutron multiplicity as a function of fission fragment mass, charge or kinetic energy, and so on. Several results related to different fissioning systems are presented in this work. The goal in the next decade will be i) to replace some macroscopic ingredients or phenomenological models by microscopic calculations when available and reliable, ii) to be a support for experimentalists in the design of detection systems or in the prediction of necessary beam time or count rates with associated statistics when measuring fragments and emitted particle in coincidence iii) extend the model to be able to run a calculation when no experimental input data are available, iv) account for multiple chance fission and gamma emission before fission, v) account for the

  19. Low energy nuclear fission

    International Nuclear Information System (INIS)

    Nifenecker, H.

    1980-08-01

    In these lectures the liquid drop model of fission is presented and some of its predictions compared with experiment. The liquid drop analogy allows to define in a rather simple and intuitive way a number of useful concepts and possible observables. It is shown how a synthesis of the liquid drop model and of the shell model can be made using the Strutinsky shell averaging procedure. Some experimental data related to the existence of shape isomers are presented and discussed. We conclude by discussing some aspects, both experimental and theoretical, of fission dynamics

  20. Fission Product Library and Resource

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Padgett, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-29

    Fission product yields can be extracted from an irradiated sample by performing gamma ray spectroscopy on the whole sample post irradiation. There are several pitfalls to avoid when trying to determine a specific isotope's fission product yield.

  1. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    The fission-like configurations are used for the total deformation energy calculations. A ... oscillator potential for the two fission fragment regions reads as ... Beyond this limit, the contribution of more remote levels is negligible. Once the density ...

  2. Mirror fusion--fission hybrids

    International Nuclear Information System (INIS)

    Lee, J.D.

    1978-01-01

    The fusion-fission concept and the mirror fusion-fission hybrid program are outlined. Magnetic mirror fusion drivers and blankets for hybrid reactors are discussed. Results of system analyses are presented and a reference design is described

  3. Process for treating fission waste

    International Nuclear Information System (INIS)

    Rohrmann, C.A.; Wick, O.J.

    1983-01-01

    A method is described for the treatment of fission waste. A glass forming agent, a metal oxide, and a reducing agent are mixed with the fission waste and the mixture is heated. After melting, the mixture separates into a glass phase and a metal phase. The glass phase may be used to safely store the fission waste, while the metal phase contains noble metals recovered from the fission waste

  4. Measurement of the 235U/238U fission cross section ratio in the 235U fission neutron spectrum

    International Nuclear Information System (INIS)

    Azimi-Garakani, D.; Bagheri-Darbandi, M.

    1983-06-01

    Fission cross section ratio of 235 U to 238 U has been measured in the fast neutron field generated by the 235 U fission plate installed on the thermal column of the Tehran Research Reactor (TRR) with a Makrofol solid state nuclear track detector. The experiments were carried out with a set of total six enriched 235 U and depleted 238 U deposits with different masses and Makrofol films of 0.025mm and 0.060mm thicknesses. The chemically etched tracks were counted by an optical microscope. No significant differences were observed with the thin and the thick films. The results showed that the average fission cross section ratio is 3.83+-0.25. (author)

  5. 50 years of nuclear fission

    International Nuclear Information System (INIS)

    Hilscher, D.

    1989-01-01

    The article tells the story of the discovery of nuclear fission in Berlin 50 years ago by Otto Hahn and Fritz Strassmann in cooperation with Lise Meitner. 50 years later nuclear fission is still a subject of research. Some question remain unanswered. Selected new research results are used to discuss the dynamics of the collective movement of the elementary nuclear fission process. (orig.) [de

  6. Fission dynamics of hot nuclei

    Indian Academy of Sciences (India)

    2014-04-05

    Apr 5, 2014 ... across the fission barrier is very small or in other words, the fission barrier is much ... of this shape evolution, the gross features of the fissioning nucleus can be described ..... [7] Y Abe, C Gregoire and H Delagrange, J. Phys.

  7. Status of fission yield measurements

    International Nuclear Information System (INIS)

    Maeck, W.J.

    1979-01-01

    Fission yield measurement and yield compilation activities in the major laboratories of the world are reviewed. In addition to a general review of the effort of each laboratory, a brief summary of yield measurement activities by fissioning nuclide is presented. A new fast reactor fission yield measurement program being conducted in the US is described

  8. Novel effector phenotype of Tim-3+ regulatory T cells leads to enhanced suppressive function in head and neck cancer patients.

    Science.gov (United States)

    Liu, Zhuqing; McMichael, Elizabeth L; Shayan, Gulidanna; Li, Jing; Chen, Kevin; Srivastava, Raghvendra M; Kane, Lawrence P; Lu, Binfeng; Ferris, Robert L

    2018-04-30

    Regulatory T (Treg) cells are important suppressive cells among tumor infiltrating lymphocytes (TIL). Treg express the well-known immune checkpoint receptor PD-1, which is reported to mark "exhausted" Treg with lower suppressive function. T cell immunoglobulin mucin (Tim)-3, a negative regulator of Th1 immunity, is expressed by a sizeable fraction of TIL Tregs, but the functional status of Tim-3+ Tregs remains unclear. CD4+CTLA-4+CD25high Treg were sorted from freshly excised head and neck squamous cell carcinoma (HNSCC) TIL based on Tim-3 expression. Functional and phenotypic features of these Tim-3+ and Tim-3- TIL Tregs were tested by in vitro suppression assays and multi-color flow cytometry. Gene expression profiling and NanoString analysis of Tim-3+ TIL Treg were performed. A murine HNSCC tumor model was used to test the effect of anti-PD-1 immunotherapy on Tim-3+ Treg.  Results: Despite high PD-1 expression, Tim-3+ TIL Treg displayed a greater capacity to inhibit naïve T cell proliferation than Tim-3- Treg. Tim-3+ Treg from human HNSCC TIL also displayed an effector-like phenotype, with more robust expression of CTLA-4, PD-1, CD39 and IFN-γ receptor. Exogenous IFN-γ treatment could partially reverse the suppressive function of Tim-3+ TIL Treg. Anti-PD-1 immunotherapy downregulated Tim-3 expression on Tregs isolated from murine HNSCC tumors, and this treatment reversed the suppressive function of HNSCC TIL Tregs. Tim-3+ Treg are functionally and phenotypically distinct in HNSCC TIL, and are highly effective at inhibiting T cell proliferation despite high PD-1 expression.  IFN-γ induced by anti-PD-1 immunotherapy may be beneficial by reversing Tim-3+ Treg suppression. Copyright ©2018, American Association for Cancer Research.

  9. The discovery of fission

    International Nuclear Information System (INIS)

    McKay, H.A.C.

    1978-01-01

    In this article by the retired head of the Separation Processes Group of the Chemistry Division, Atomic Energy Research Establishment, Harwell, U.K., the author recalls what he terms 'an exciting drama, the unravelling of the nature of the atomic nucleus' in the years before the Second World War, including the discovery of fission. 12 references. (author)

  10. A comparative study of isotopic analysis of plutonium from organic and aqueous media by thermal ionization mass spectrometry (TIMS)

    International Nuclear Information System (INIS)

    Rao, Radhika M.; Mirashi, Nirupama N.; Khodade, P.S.; Shah, P.M.; Parab, A.R.; Govindan, R.; Aggarwal, S.K.

    2003-01-01

    For isotopic analysis of plutonium (Pu) in irradiated nuclear fuel samples, it is normally separated from Am, U and fission products by anion exchange method in nitrate medium. However, stripping of Pu from the column by dilute HNO 3 acid is slow due to tailing which requires long elution times and reduces the concentration of Pu in the eluted solution. The desorption of Pu from the column can be enhanced by using more dilute HNO 3 but there are problems of hydrolysis and polymer formation. Formic acid and ascorbic acid in formic acid are reported to be promising eluents for plutonium. Formic acid is also a good solvent for Pu. Further, the presence of ascorbic acid helps in reducing Pu (IV) to Pu (III) thereby leading to faster elution as well as better recovery in smaller volumes of the eluant and hence higher Pu concentrations in the collected fraction. This would circumvent the need of subsequent concentration steps allowing direct loading of Pu on the filament for analysis by TIMS. The aim of the present work was to compare the elution behaviour and mass spectrometric analysis of Pu using formic acid, formic acid + ascorbic acid and nitric acid with respect to ion current behaviour and isotopic ratios obtained

  11. Monte-Carlo Generation of Time Evolving Fission Chains

    Energy Technology Data Exchange (ETDEWEB)

    Verbeke, Jerome M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kim, Kenneth S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Prasad, Manoj K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, Neal J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-08-01

    About a decade ago, a computer code was written to model neutrons from their “birth” to their final “death” in thermal neutron detectors (3He tubes): SrcSim had enough physics to track the neutrons in multiplying systems, appropriately increasing and decreasing the neutron population as they interacted by absorption, fission and leakage. The theory behind the algorithms assumed that all neutrons produced in a fission chain were all produced simultaneously, and then diffused to the neutron detectors. For cases where the diffusion times are long compared to the fission chains, SrcSim is very successful. Indeed, it works extraordinarily well for thermal neutron detectors and bare objects, because it takes tens of microseconds for fission neutrons to slow down to thermal energies, where they can be detected. Microseconds are a very long time compared to the lengths of the fission chains. However, this inherent assumption in the theory prevents its use to cases where either the fission chains are long compared to the neutron diffusion times (water-cooled nuclear reactors, or heavily moderated object, where the theory starts failing), or the fission neutrons can be detected shortly after they were produced (fast neutron detectors). For these cases, a new code needs to be written, where the underlying assumption is not made. The purpose of this report is to develop an algorithm to generate the arrival times of neutrons in fast neutron detectors, starting from a neutron source such as a spontaneous fission source (252Cf) or a multiplying source (Pu). This code will be an extension of SrcSim to cases where correlations between neutrons in the detectors are on the same or shorter time scales as the fission chains themselves.

  12. Anticipating Deep Mapping: Tracing the Spatial Practice of Tim Robinson

    Directory of Open Access Journals (Sweden)

    Jos Smith

    2015-07-01

    Full Text Available There has been little academic research published on the work of Tim Robinson despite an illustrious career, first as an artist of the London avant-garde, then as a map-maker in the west of Ireland, and finally as an author of place. In part, this dearth is due to the difficulty of approaching these three diverse strands collectively. However, recent developments in the field of deep mapping encourage us to look back at the continuity of Robinson’s achievements in full and offer a suitable framework for doing so. Socially engaged with living communities and a depth of historical knowledge about place, but at the same time keen to contribute artistically to the ongoing contemporary culture of place, the parameters of deep mapping are broad enough to encompass the range of Robinson’s whole practice and suggest unique ways to illuminate his very unusual career. But Robinson’s achievements also encourage a reflection on the historical context of deep mapping itself, as well as on the nature of its spatial practice (especially where space comes to connote a medium to be worked rather than an area/volume. With this in mind the following article both explores Robinson’s work through deep mapping and deep mapping through the work of this unusual artist.

  13. Sensor 17 Thermal Isolation Mounting Structure (TIMS) Design Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Enstrom, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-04

    The SENSOR 17 thermographic camera weighs approximately 0.5lbs, has a fundamental mode of 167 Hz, and experiences 0.75W of heat leakage in through the TIMS. The configuration, shown in Figure 1, is comprised of four 300 Series SST washers paired in tandem with P.E.I (Ultem 100) washers. The SENSOR 17 sensor is mounted to a 300 series stainless plate with A-shaped arms. The Plate can be assumed to be at ambient temperatures (≈293K) and the I.R. Mount needs to be cooled to 45K. It is attached to the tip of a cryocooler by a ‘cold strap’ and is assumed to be at the temperature of the cold-strap (≈45K). During flights SENSOR 17 experiences excitations at frequencies centered around 10-30Hz, 60Hz, and 120Hz from the aircraft flight environment. The temporal progression described below depicts the 1st Modal shape at the systems resonant frequency. This simulation indicates Modal articulation will cause a pitch rate of the camera with respect to the body axis of the airplane. This articulation shows up as flutter in the camera.

  14. Ebola Virus Binding to Tim-1 on T Lymphocytes Induces a Cytokine Storm

    Directory of Open Access Journals (Sweden)

    Patrick Younan

    2017-09-01

    Full Text Available Ebola virus (EBOV disease (EVD results from an exacerbated immunological response that is highlighted by a burst in the production of inflammatory mediators known as a “cytokine storm.” Previous reports have suggested that nonspecific activation of T lymphocytes may play a central role in this phenomenon. T-cell immunoglobulin and mucin domain-containing protein 1 (Tim-1 has recently been shown to interact with virion-associated phosphatidylserine to promote infection. Here, we demonstrate the central role of Tim-1 in EBOV pathogenesis, as Tim-1−/− mice exhibited increased survival rates and reduced disease severity; surprisingly, only a limited decrease in viremia was detected. Tim-1−/− mice exhibited a modified inflammatory response as evidenced by changes in serum cytokines and activation of T helper subsets. A series of in vitro assays based on the Tim-1 expression profile on T cells demonstrated that despite the apparent absence of detectable viral replication in T lymphocytes, EBOV directly binds to isolated T lymphocytes in a phosphatidylserine–Tim-1-dependent manner. Exposure to EBOV resulted in the rapid development of a CD4Hi CD3Low population, non-antigen-specific activation, and cytokine production. Transcriptome and Western blot analysis of EBOV-stimulated CD4+ T cells confirmed the induction of the Tim-1 signaling pathway. Furthermore, comparative analysis of transcriptome data and cytokine/chemokine analysis of supernatants highlight the similarities associated with EBOV-stimulated T cells and the onset of a cytokine storm. Flow cytometry revealed virtually exclusive binding and activation of central memory CD4+ T cells. These findings provide evidence for the role of Tim-1 in the induction of a cytokine storm phenomenon and the pathogenesis of EVD.

  15. Elastocapillary Instability in Mitochondrial Fission

    Science.gov (United States)

    Gonzalez-Rodriguez, David; Sart, Sébastien; Babataheri, Avin; Tareste, David; Barakat, Abdul I.; Clanet, Christophe; Husson, Julien

    2015-08-01

    Mitochondria are dynamic cell organelles that constantly undergo fission and fusion events. These dynamical processes, which tightly regulate mitochondrial morphology, are essential for cell physiology. Here we propose an elastocapillary mechanical instability as a mechanism for mitochondrial fission. We experimentally induce mitochondrial fission by rupturing the cell's plasma membrane. We present a stability analysis that successfully explains the observed fission wavelength and the role of mitochondrial morphology in the occurrence of fission events. Our results show that the laws of fluid mechanics can describe mitochondrial morphology and dynamics.

  16. A threshold for dissipative fission

    International Nuclear Information System (INIS)

    Thoennessen, M.; Bertsch, G.F.

    1993-01-01

    The empirical domain of validity of statistical theory is examined as applied to fission data on pre-fission data on pre-fission neutron, charged particle, and γ-ray multiplicities. Systematics are found of the threshold excitation energy for the appearance of nonstatistical fission. From the data on systems with not too high fissility, the relevant phenomenological parameter is the ratio of the threshold temperature T thresh to the (temperature-dependent) fission barrier height E Bar (T). The statistical model reproduces the data for T thresh /E Bar (T) thresh /E Bar (T) independent of mass and fissility of the systems

  17. Taming dendritic cells with TIM-3: Another immunosuppressive strategy by tumors

    Science.gov (United States)

    Patel, Jaina; Bozeman, Erica N.; Selvaraj, Periasamy

    2013-01-01

    The identification of TIM-3 expression on tumor associated dendritic cells (TADCs) provides insight into another aspect of tumor-mediated immunosuppression. The role of TIM-3 has been well characterized on tumor-infiltrating T cells, however its role on TADCs was not previously known. The current paper demonstrated that TIM-3 was predominantly expressed by TADCs and its interaction with the nuclear protein HMGB1 suppressed nucleic acid mediated activation of an effective antitumor immune response. The authors were able to show that TIM-3 interaction with HMGB1 prevented the localization of nucleic acids into endosomal vesicles. Furthermore, chemotherapy was found to be more effective in anti-TIM-3 mAb treated mice or mice depleted of all DCs which indicated that significant role played by TADCs inhibiting tumor regression. Taken together, these findings identify TIM-3 as a potential target for inducing antitumor immunity in conjunction with DNA vaccines and/or immunogenic chemotherapy in clinical settings. PMID:23240746

  18. The TIM and TAM families of phosphatidylserine receptors mediate dengue virus entry.

    Science.gov (United States)

    Meertens, Laurent; Carnec, Xavier; Lecoin, Manuel Perera; Ramdasi, Rasika; Guivel-Benhassine, Florence; Lew, Erin; Lemke, Greg; Schwartz, Olivier; Amara, Ali

    2012-10-18

    Dengue viruses (DVs) are responsible for the most medically relevant arboviral diseases. However, the molecular interactions mediating DV entry are poorly understood. We determined that TIM and TAM proteins, two receptor families that mediate the phosphatidylserine (PtdSer)-dependent phagocytic removal of apoptotic cells, serve as DV entry factors. Cells poorly susceptible to DV are robustly infected after ectopic expression of TIM or TAM receptors. Conversely, DV infection of susceptible cells is inhibited by anti-TIM or anti-TAM antibodies or knockdown of TIM and TAM expression. TIM receptors facilitate DV entry by directly interacting with virion-associated PtdSer. TAM-mediated infection relies on indirect DV recognition, in which the TAM ligand Gas6 acts as a bridging molecule by binding to PtdSer within the virion. This dual mode of virus recognition by TIM and TAM receptors reveals how DVs usurp the apoptotic cell clearance pathway for infectious entry. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Barium 139 as Fission Indicator

    Energy Technology Data Exchange (ETDEWEB)

    Broda, E.

    1943-07-01

    This report is based on a measurement performed at the Cavendish Laboratory (Cambridge) by E. Broda in December 1943 where a technique has been worked out for measuring the fission density in a uranium containing medium in relative units by determining the amount of a suitable fission product formed. Generally a given fission product will be formed in natural uranium by slow neutron fission of U235 or by fast neutron fission of either U235 or U238. It is intended to translate the relative units into absolute units by comparison of the Ba yield with the indication of UF6 fission chamber in the same medium. This has to be done separately for fast and slow neutron fission as the yields may be different. Another application of the technique developed is the measurement of thermal neutron density in an uraniferous medium without using a detector subject to variations of sensitivity according to the properties of the medium. (nowak)

  20. Downregulation of TIM-3 mRNA expression in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Cai, X.Z. [Central Laboratory, First Affiliated Hospital, China Medical University, Shenyang (China); Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang (China); Huang, W.Y.; Qiao, Y.; Chen, Y.; Du, S.Y.; Chen, D.; Yu, S. [Central Laboratory, First Affiliated Hospital, China Medical University, Shenyang (China); Liu, N. [Department of Nephrology, First Affiliated Hospital, China Medical University, Shenyang (China); Dou, L.Y. [Central Laboratory, First Affiliated Hospital, China Medical University, Shenyang (China); Jiang, Y. [Central Laboratory, First Affiliated Hospital, China Medical University, Shenyang (China); Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang (China); Department of Dermatology, First Affiliated Hospital, China Medical University, Shenyang (China)

    2014-10-17

    The T-cell immunoglobulin and mucin domain (TIM) family is associated with autoimmune diseases, but its expression level in the immune cells of systemic lupus erythematosus (SLE) patients is not known. The aim of this study was to investigate whether the expression of TIM-3 mRNA is associated with pathogenesis of SLE. Quantitative real-time reverse transcription-polymerase chain reaction analysis (qRT-PCR) was used to determine TIM-1, TIM-3, and TIM-4 mRNA expression in peripheral blood mononuclear cells (PBMCs) from 132 patients with SLE and 62 healthy controls. The PBMC surface protein expression of TIMs in PBMCs from 20 SLE patients and 15 healthy controls was assayed by flow cytometry. Only TIM-3 mRNA expression decreased significantly in SLE patients compared with healthy controls (P<0.001). No significant differences in TIM family protein expression were observed in leukocytes from SLE patients and healthy controls (P>0.05). SLE patients with lupus nephritis (LN) had a significantly lower expression of TIM-3 mRNA than those without LN (P=0.001). There was no significant difference in the expression of TIM-3 mRNA within different classes of LN (P>0.05). Correlation of TIM-3 mRNA expression with serum IgA was highly significant (r=0.425, P=0.004), but was weakly correlated with total serum protein (r{sub s}=0.283, P=0.049) and serum albumin (r{sub s}=0.297, P=0.047). TIM-3 mRNA expression was weakly correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI; r{sub s}=-0.272, P=0.032). Our results suggest that below-normal expression of TIM-3 mRNA in PBMC may be involved in the pathogenesis of SLE.

  1. Downregulation of TIM-3 mRNA expression in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Cai, X.Z.; Huang, W.Y.; Qiao, Y.; Chen, Y.; Du, S.Y.; Chen, D.; Yu, S.; Liu, N.; Dou, L.Y.; Jiang, Y.

    2014-01-01

    The T-cell immunoglobulin and mucin domain (TIM) family is associated with autoimmune diseases, but its expression level in the immune cells of systemic lupus erythematosus (SLE) patients is not known. The aim of this study was to investigate whether the expression of TIM-3 mRNA is associated with pathogenesis of SLE. Quantitative real-time reverse transcription-polymerase chain reaction analysis (qRT-PCR) was used to determine TIM-1, TIM-3, and TIM-4 mRNA expression in peripheral blood mononuclear cells (PBMCs) from 132 patients with SLE and 62 healthy controls. The PBMC surface protein expression of TIMs in PBMCs from 20 SLE patients and 15 healthy controls was assayed by flow cytometry. Only TIM-3 mRNA expression decreased significantly in SLE patients compared with healthy controls (P<0.001). No significant differences in TIM family protein expression were observed in leukocytes from SLE patients and healthy controls (P>0.05). SLE patients with lupus nephritis (LN) had a significantly lower expression of TIM-3 mRNA than those without LN (P=0.001). There was no significant difference in the expression of TIM-3 mRNA within different classes of LN (P>0.05). Correlation of TIM-3 mRNA expression with serum IgA was highly significant (r=0.425, P=0.004), but was weakly correlated with total serum protein (r s =0.283, P=0.049) and serum albumin (r s =0.297, P=0.047). TIM-3 mRNA expression was weakly correlated with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI; r s =-0.272, P=0.032). Our results suggest that below-normal expression of TIM-3 mRNA in PBMC may be involved in the pathogenesis of SLE

  2. Fusion-fission dynamics

    International Nuclear Information System (INIS)

    Blocki, J.; Planeta, R.; Brzychczyk, J.; Grotowski, K.

    1991-04-01

    Classical dynamical calculations of the heavy ion induced fission process for the reactions 40 Ar+ 141 Pr, 20 Ne+ 165 Ho and 12 C+ 175 Lu leading to the iridium like nucleus have been performed. As a result prescission lifetimes were obtained and compared with the experimental values. The agreement between the calculated and experimental lifetimes indicates that the one-body dissipation picture is much more relevant in describing the fusion-fission dynamics than the two-body one. Somewhat bigger calculated times than the experimental ones in case of the C+Lu reaction at 16 MeV/nucleon may be a signal on the energy range applicability of the one-body dissipation model. (author)

  3. [Fission product yields of 60 fissioning reactions]. Final report

    International Nuclear Information System (INIS)

    Rider, B.F.

    1995-01-01

    In keeping with the statement of work, I have examined the fission product yields of 60 fissioning reactions. In co-authorship with the UTR (University Technical Representative) Talmadge R. England ''Evaluation and Compilation of Fission Product Yields 1993,'' LA-UR-94-3106(ENDF-349) October, (1994) was published. This is an evaluated set of fission product Yields for use in calculation of decay heat curves with improved accuracy has been prepared. These evaluated yields are based on all known experimental data through 1992. Unmeasured fission product yields are calculated from charge distribution, pairing effects, and isomeric state models developed at Los Alamos National Laboratory. The current evaluation has been distributed as the ENDF/B-VI fission product yield data set

  4. Efficiency calibration of solid track spark auto counter

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Liu Rong; Jiang Li; Lu Xinxin; Zhu Tonghua

    2008-01-01

    The factors influencing detection efficiency of solid track spark auto counter were analyzed, and the best etch condition and parameters of charge were also reconfirmed. With small plate fission ionization chamber, the efficiency of solid track spark auto counter at various experiment assemblies was re-calibrated. The efficiency of solid track spark auto counter at various experimental conditions was obtained. (authors)

  5. Coulomb fission and transfer fission at heavy ion collisions

    International Nuclear Information System (INIS)

    Himmele, G.

    1981-01-01

    In the present thesis the first direct evidence of nuclear fission after inelastic scattering of heavy ions (sup(183,184)W, 152 Sm → 238 U; 184 W → 232 Th; 184 W, 232 Th → 248 Cm) is reported. Experiments which were performed at the UNILAC of the Gesellschaft fuer Schwerionenforschung in Darmstadt show the observed heavy ion induced fission possesses significant properties of the Coulomb fission. The observed dependence of the fission probability for inelastic scattering on the projectile charge proves that the nuclear fission is mediated by the electromagnetic interaction between heavy ions. This result suggests moreover a multiple Coulomb-excitation preceding the fission. Model calculations give a first indication, that the Coulomb fission proceeds mainly from the higher β phonons. In the irradiation with 184 W the fission probability of 232 Th is for all incident energies about 40% smaller that at 238 U. The target dependence of the Coulomb fission however doesn't allow, to give quantitative statements about the position and B(E2)-values of higher lying β phonons. (orig./HSI) [de

  6. Drosophila TIM binds importin α1, and acts as an adapter to transport PER to the nucleus.

    Science.gov (United States)

    Jang, A Reum; Moravcevic, Katarina; Saez, Lino; Young, Michael W; Sehgal, Amita

    2015-02-01

    Regulated nuclear entry of clock proteins is a conserved feature of eukaryotic circadian clocks and serves to separate the phase of mRNA activation from mRNA repression in the molecular feedback loop. In Drosophila, nuclear entry of the clock proteins, PERIOD (PER) and TIMELESS (TIM), is tightly controlled, and impairments of this process produce profound behavioral phenotypes. We report here that nuclear entry of PER-TIM in clock cells, and consequently behavioral rhythms, require a specific member of a classic nuclear import pathway, Importin α1 (IMPα1). In addition to IMPα1, rhythmic behavior and nuclear expression of PER-TIM require a specific nuclear pore protein, Nup153, and Ran-GTPase. IMPα1 can also drive rapid and efficient nuclear expression of TIM and PER in cultured cells, although the effect on PER is mediated by TIM. Mapping of interaction domains between IMPα1 and TIM/PER suggests that TIM is the primary cargo for the importin machinery. This is supported by attenuated interaction of IMPα1 with TIM carrying a mutation previously shown to prevent nuclear entry of TIM and PER. TIM is detected at the nuclear envelope, and computational modeling suggests that it contains HEAT-ARM repeats typically found in karyopherins, consistent with its role as a co-transporter for PER. These findings suggest that although PER is the major timekeeper of the clock, TIM is the primary target of nuclear import mechanisms. Thus, the circadian clock uses specific components of the importin pathway with a novel twist in that TIM serves a karyopherin-like role for PER.

  7. A small flat fission chamber

    International Nuclear Information System (INIS)

    Li Yijun; Wang Dalun; Chen Suhe

    1999-01-01

    With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

  8. Fission barriers of light nuclei

    International Nuclear Information System (INIS)

    Grotowski, K.; Planeta, R.; Blann, M.; Komoto, T.

    1989-01-01

    Experimental fission excitation functions for compound nuclei /sup 52/Fe, /sup 49/Cr, /sup 46/V, and /sup 44/Ti formed in heavy-ion reactions are analyzed in the Hauser-Feshbach/Bohr-Wheeler formalism using fission barriers based on the rotating liquid drop model of Cohen et al. and on the rotating finite range model of Sierk. We conclude that the rotating finite range approach gives better reproduction of experimental fission yields, consistent with results found for heavier systems

  9. Preparation and characterization of a novel nanobody against T-cell immunoglobulin and mucin-3 (TIM-3).

    Science.gov (United States)

    Homayouni, Vida; Ganjalikhani-Hakemi, Mazdak; Rezaei, Abbas; Khanahmad, Hossein; Behdani, Mahdi; Lomedasht, Fatemeh Kazemi

    2016-11-01

    As T-cell immunoglobulin and mucin domain 3 (TIM-3) is an immune regulatory molecule; its blocking or stimulating could alter the pattern of immune response towards a desired condition. Based on the unique features of nanobodies, we aimed to construct an anti-TIM-3 nanobody as an appropriate tool for manipulating immune responses for future therapeutic purposes. We immunized a camel with TIM-3 antigen and then, synthesized a VHH phage: mid library from its B cell's transcriptome using nested PCR. Library selection against TIM-3antigen was performed in three rounds of panning. Using phage-ELISA, the most reactive colonies were selected for sub-cloning in soluble protein expression vectors. The Nanobody was purified and confirmed with a nickel-nitrilotriacetic acid (Ni-NTA) column, SDS-PAGE and Western blotting. A flowcytometric analysis was performed to analyze the binding and biologic activities of theTIM-3 specific nanobody with TIM-3 expressing HL-60 and HEK cell lines. Specific 15kD band representing for nanobody was observed on the gel and confirmed with Western blotting. The nanobody showed significant specific immune-reactivity against TIM-3 with a relatively high binding affinity. The nanobody significantly suppressed the proliferation of TIM-3 expressing HL-60 cell line. Finally, we successfully prepared a functional anti-humanTIM-3 specific nanobody with a high affinity and an anti-proliferative activity on an AML cell line in vitro.

  10. Ebola Virus Binding to Tim-1 on T Lymphocytes Induces a Cytokine Storm.

    Science.gov (United States)

    Younan, Patrick; Iampietro, Mathieu; Nishida, Andrew; Ramanathan, Palaniappan; Santos, Rodrigo I; Dutta, Mukta; Lubaki, Ndongala Michel; Koup, Richard A; Katze, Michael G; Bukreyev, Alexander

    2017-09-26

    Ebola virus (EBOV) disease (EVD) results from an exacerbated immunological response that is highlighted by a burst in the production of inflammatory mediators known as a "cytokine storm." Previous reports have suggested that nonspecific activation of T lymphocytes may play a central role in this phenomenon. T-cell immunoglobulin and mucin domain-containing protein 1 (Tim-1) has recently been shown to interact with virion-associated phosphatidylserine to promote infection. Here, we demonstrate the central role of Tim-1 in EBOV pathogenesis, as Tim-1 -/- mice exhibited increased survival rates and reduced disease severity; surprisingly, only a limited decrease in viremia was detected. Tim-1 -/- mice exhibited a modified inflammatory response as evidenced by changes in serum cytokines and activation of T helper subsets. A series of in vitro assays based on the Tim-1 expression profile on T cells demonstrated that despite the apparent absence of detectable viral replication in T lymphocytes, EBOV directly binds to isolated T lymphocytes in a phosphatidylserine-Tim-1-dependent manner. Exposure to EBOV resulted in the rapid development of a CD4 Hi CD3 Low population, non-antigen-specific activation, and cytokine production. Transcriptome and Western blot analysis of EBOV-stimulated CD4 + T cells confirmed the induction of the Tim-1 signaling pathway. Furthermore, comparative analysis of transcriptome data and cytokine/chemokine analysis of supernatants highlight the similarities associated with EBOV-stimulated T cells and the onset of a cytokine storm. Flow cytometry revealed virtually exclusive binding and activation of central memory CD4 + T cells. These findings provide evidence for the role of Tim-1 in the induction of a cytokine storm phenomenon and the pathogenesis of EVD. IMPORTANCE Ebola virus infection is characterized by a massive release of inflammatory mediators, which has come to be known as a cytokine storm. The severity of the cytokine storm is

  11. Pion-induced fission of 209Bi and 119Sn: measurements, calculations, analyses and comparison

    International Nuclear Information System (INIS)

    Rana, M.A.; Sher, G.; Manzoor, S.; Shehzad, M.I.

    2011-01-01

    Cross-sections for the π - -induced fission of 209 Bi and 119 Sn have been measured using the most sensitive CR-39 solid-state nuclear track detector. In experiments, target–detector stacks were exposed to negative pions of energy 500, 672, 1068, and 1665 MeV at the Brookhaven National Laboratory, USA. An important aspect of the present paper is the comparison of pion-induced fission fragment spectra of above mentioned nuclei with the spontaneous fission fragment spectra of 252 Cf. This comparison is made in terms of fission fragment track lengths in the CR-39 detectors. Measurement results are compared with calculations of Monte Carlo and statistical weight functions methods using the computer code CEM95. Agreement between measurements and calculations is fairly good for 209 Bi target nuclei whereas it is indigent for the case of 119 Sn. The possibilities of the trustworthy calculations, using the computer code CEM95, comparable with measurements of pion-induced fission in intermediate and heavy nuclei are explored by employing various systematics available in the code. Energy dependence of pion-induced fission in 119 Sn and 209 Bi is analyzed employing a newly defined parameter geometric-size-normalized fission cross-section (χ f g ). It is found that the collective nuclear excitations, which may lead to fission, become more probable for both 209 Bi and 119 Sn nuclei with increasing energy of negative pions from 500 to 1665 MeV. (author)

  12. Nuclear Forensics and Radiochemistry: Fission

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-07

    Radiochemistry has been used to study fission since it’ discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution.

  13. Micro plate fission chamber development

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Jiang Li; Liu Rong; Wang Dalun

    2014-01-01

    To conduct the measurement of neutron flux and the fission rate distribution at several position in assemblies, the micro plate fission chamber was designed and fabricated. Since the requirement of smaller volume and less structure material was taken into consideration, it is convinient, commercial and practical to use fission chamber to measure neutron flux in specific condition. In this paper, the structure of fission chamber and process of fabrication were introduced and performance test result was presented. The detection efficiency is 91.7%. (authors)

  14. Fission yield measurements at IGISOL

    Science.gov (United States)

    Lantz, M.; Al-Adili, A.; Gorelov, D.; Jokinen, A.; Kolhinen, V. S.; Mattera, A.; Moore, I.; Penttilä, H.; Pomp, S.; Prokofiev, A. V.; Rakopoulos, V.; Rinta-Antila, S.; Simutkin, V.; Solders, A.

    2016-06-01

    The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

  15. Fission yield measurements at IGISOL

    Directory of Open Access Journals (Sweden)

    Lantz M.

    2016-01-01

    Full Text Available The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f and Th(p,f have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

  16. Fusion-fission type collisions

    International Nuclear Information System (INIS)

    Oeschler, H.

    1980-01-01

    Three examples of fusion-fission type collisions on medium-mass nuclei are investigated whether the fragment properties are consistent with fission from equilibrated compound nuclei. Only in a very narrow band of angular momenta the data fulfill the necessary criteria for this process. Continuous evolutions of this mechnism into fusion fission and into a deep-inelastic process and particle emission prior to fusion have been observed. Based on the widths of the fragment-mass distributions of a great variety of data, a further criterion for the compound-nucleus-fission process is tentatively proposed. (orig.)

  17. Thermodynamics of nuclear track chemical etching

    Science.gov (United States)

    Rana, Mukhtar Ahmed

    2018-05-01

    This is a brief paper with new and useful scientific information on nuclear track chemical etching. Nuclear track etching is described here by using basic concepts of thermodynamics. Enthalpy, entropy and free energy parameters are considered for the nuclear track etching. The free energy of etching is determined using etching experiments of fission fragment tracks in CR-39. Relationship between the free energy and the etching temperature is explored and is found to be approximately linear. The above relationship is discussed. A simple enthalpy-entropy model of chemical etching is presented. Experimental and computational results presented here are of fundamental interest in nuclear track detection methodology.

  18. TIM-3 as a Target for Cancer Immunotherapy and Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Wenwen Du

    2017-03-01

    Full Text Available Cancer immunotherapy has produced impressive clinical results in recent years. Despite the success of the checkpoint blockade strategies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4 and programmed death receptor 1 (PD-1, a large portion of cancer patients have not yet benefited from this novel therapy. T cell immunoglobulin and mucin domain 3 (TIM-3 has been shown to mediate immune tolerance in mouse models of infectious diseases, alloimmunity, autoimmunity, and tumor Immunity. Thus, targeting TIM-3 emerges as a promising approach for further improvement of current immunotherapy. Despite a large amount of experimental data showing an immune suppressive function of TIM-3 in vivo, the exact mechanisms are not well understood. To enable effective targeting of TIM-3 for tumor immunotherapy, further in-depth mechanistic studies are warranted. These studies will also provide much-needed insight for the rational design of novel combination therapy with other checkpoint blockers. In this review, we summarize key evidence supporting an immune regulatory role of TIM-3 and discuss possible mechanisms of action.

  19. Study on the effect factor of the absolute fission rates measured by depleted uranium fission chamber

    International Nuclear Information System (INIS)

    Jiang Li; Liu Rong; Wang Dalun; Wang Mei; Lin Jufang; Wen Zhongwei

    2003-01-01

    The absolute fission rates was measured by the depleted uranium fission chamber. The efficiency of the fission fragments recorded in the fission chamber was analyzed. The factor influencing absolute fission rates was studied in the experiment, including the disturbing effect between detectors and the effect of the structural of the fission chamber, etc

  20. Energy from nuclear fission()

    Science.gov (United States)

    Ripani, M.

    2015-08-01

    The main features of nuclear fission as physical phenomenon will be revisited, emphasizing its peculiarities with respect to other nuclear reactions. Some basic concepts underlying the operation of nuclear reactors and the main types of reactors will be illustrated, including fast reactors, showing the most important differences among them. The nuclear cycle and radioactive-nuclear-waste production will be also discussed, along with the perspectives offered by next generation nuclear assemblies being proposed. The current situation of nuclear power in the world, its role in reducing carbon emission and the available resources will be briefly illustrated.

  1. Measurement of Fission Product Yields from Fast-Neutron Fission

    Science.gov (United States)

    Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Henderson, R.; Kenneally, J.; Macri, R.; McNabb, D.; Ryan, C.; Sheets, S.; Stoyer, M. A.; Tonchev, A. P.; Bhatia, C.; Bhike, M.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.

    2014-09-01

    One of the aims of the Stockpile Stewardship Program is a reduction of the uncertainties on fission data used for analyzing nuclear test data [1,2]. Fission products such as 147Nd are convenient for determining fission yields because of their relatively high yield per fission (about 2%) and long half-life (10.98 days). A scientific program for measuring fission product yields from 235U,238U and 239Pu targets as a function of bombarding neutron energy (0.1 to 15 MeV) is currently underway using monoenergetic neutron beams produced at the 10 MV Tandem Accelerator at TUNL. Dual-fission chambers are used to determine the rate of fission in targets during activation. Activated targets are counted in highly shielded HPGe detectors over a period of several weeks to identify decaying fission products. To date, data have been collected at neutron bombarding energies 4.6, 9.0, 14.5 and 14.8 MeV. Experimental methods and data reduction techniques are discussed, and some preliminary results are presented.

  2. Fission of intermediate mass nuclei by photons of stopping radiation in the maximum energy range 0,8 - 1,8 MeV

    International Nuclear Information System (INIS)

    Lima, D.A. de.

    1983-07-01

    The fission of intermediate mass nuclei in Al - Ta interval, induced by stopping radiation phtons of maximum energies between 0,8 and 1.8 GeV is studied. Nd and Sm thin targets and Al, Ti, Co, Zr, Nb, Ag, In and Ta thick targets were used, considering all peculiarities inherent to absorption of fission fragments in the target. The samples were exposed into the 2.5 GeV Electron Synchrotron in Bonn Univerity. The fission fragment tracks were registered in foil type detectors using mica muscovite for Sm and Nd, CR-39 for Al and Ti and makrofol for Co, Zr; Nb, Ag, In, Nd and Ta. The track length and track depth angle distributions were measured for determining fission efficiencies. The fission cross sections and nuclear fissionable of the studied elements were evaluated. (M.C.K.) [pt

  3. Tip model of cold fission

    International Nuclear Information System (INIS)

    Goennenwein, F.; Boersig, B.

    1991-01-01

    Cold fission is defined to be the limiting case of nuclear fission where virtually all of the available energy is converted into the total kinetic energy of the fragments. The fragments have, therefore, to be born in or at least close to their respective ground states. Starting from the viewpoint that cold fission corresponds to most compact scission configurations, energy constraints have been exploited to calculate minimum tip distances between the two nascent fragments in binary fission. Crucial input parameters to this tip model of cold fission are the ground-state deformations of fragment nuclei. It is shown that the minimum tip distances being compatible with energy conservation vary strongly with both the mass and charge fragmentation of the fission prone nucleus. The tip distances refer to nuclei with equivalent sharp surfaces. In keeping with the size of the surface width of leptodermous nuclei, only configurations where the tip distances are smaller than a few fm may be considered as valid scission configurations. From a comparison with experimental data on cold fission this critical tip distance appears to be 3.0 fm for the model parameters chosen. Whenever the model calculation yields tip distances being smaller than the critical value, a necessary condition for attaining cold fission is considered to be fulfilled. It is shown that this criterion allows to understand in fair agreement with experiment which mass fragmentations are susceptible to lead to cold fission and which fragment-charge divisions are the most favored in each isobaric mass chain. Being based merely on energy arguments, the model cannot aim at predicting fragment yields in cold fission. However, the tip model proposed appears well suited to delineate the phase space where cold fission phenomena may come into sight. (orig.)

  4. Post-scission fission theory: Neutron emission in fission

    International Nuclear Information System (INIS)

    Madland, D.G.

    1997-01-01

    A survey of theoretical representations of two of the observables in neutron emission in fission is given, namely, the prompt fission neutron spectrum N (E) and the average prompt neutron multiplicity bar ν p . Early representations of the two observables are presented and their deficiencies are discussed. This is followed by summaries and examples of recent theoretical models for the calculation of these quantities. Emphasis is placed upon the predictability and accuracy of the recent models. In particular, the dependencies of N (E) and bar ν p upon the fissioning nucleus and its excitation energy are treated. Recent work in the calculation of the prompt fission neutron spectrum matrix N (E, E n ), where E n is the energy of the neutron inducing fission, is then discussed. Concluding remarks address the current status of our ability to calculate these observables with confidence, the direction of future theoretical efforts, and limitations to current (and future) approaches

  5. Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

    Energy Technology Data Exchange (ETDEWEB)

    Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar; Baker, Erin M.; Liu, Tao; Smith, Richard D.; Fernandez-Lima, Francisco

    2018-05-01

    Abstract. In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150–250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMSCID- TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptide biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10–200 nM range, while simultaneously achieving discovery measurements

  6. Influence of tracks densities in solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Guedes O, S.; Hadler N.; Lunes, P.; Saenz T, C.

    1996-01-01

    When Solid State Nuclear Track Detectors (SSNTD) is employed to measure nuclear tracks produced mainly by fission fragments and alpha particles, it is considered that the tracks observation work is performed under an efficiency, ε 0 , which is independent of the track density (number of tracks/area unit). There are not published results or experimental data supporting such an assumption. In this work the dependence of ε 0 with track density is studied basing on experimental data. To perform this, pieces of CR-39 cut from a sole 'mother sheet' were coupled to thin uranium films for different exposition times and the resulting ratios between track density and exposition time were compared. Our results indicate that ε 0 is constant for track densities between 10 3 and 10 5 cm -2 . At our etching conditions track overlapping makes impossible the counting for densities around 1.7 x 10 5 cm -2 . For track densities less than 10 3 cm -2 , ε 0 , was not observed to be constant. (authors). 4 refs., 2 figs

  7. TIM, a ray-tracing program for METATOY research and its dissemination

    Science.gov (United States)

    Lambert, Dean; Hamilton, Alasdair C.; Constable, George; Snehanshu, Harsh; Talati, Sharvil; Courtial, Johannes

    2012-03-01

    TIM (The Interactive METATOY) is a ray-tracing program specifically tailored towards our research in METATOYs, which are optical components that appear to be able to create wave-optically forbidden light-ray fields. For this reason, TIM possesses features not found in other ray-tracing programs. TIM can either be used interactively or by modifying the openly available source code; in both cases, it can easily be run as an applet embedded in a web page. Here we describe the basic structure of TIM's source code and how to extend it, and we give examples of how we have used TIM in our own research. Program summaryProgram title: TIM Catalogue identifier: AEKY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 124 478 No. of bytes in distributed program, including test data, etc.: 4 120 052 Distribution format: tar.gz Programming language: Java Computer: Any computer capable of running the Java Virtual Machine (JVM) 1.6 Operating system: Any; developed under Mac OS X Version 10.6 RAM: Typically 145 MB (interactive version running under Mac OS X Version 10.6) Classification: 14, 18 External routines: JAMA [1] (source code included) Nature of problem: Visualisation of scenes that include scene objects that create wave-optically forbidden light-ray fields. Solution method: Ray tracing. Unusual features: Specifically designed to visualise wave-optically forbidden light-ray fields; can visualise ray trajectories; can visualise geometric optic transformations; can create anaglyphs (for viewing with coloured "3D glasses") and random-dot autostereograms of the scene; integrable into web pages. Running time: Problem-dependent; typically seconds for a simple scene.

  8. Fission fragment driven neutron source

    Science.gov (United States)

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  9. Neutron multiplicity of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Abdelrahman, Y S [Physics department, mu` rah university Al-Karak, (Jordan)

    1995-10-01

    The total average neutron multiplicity of the fission fragments produced by the spontaneous fission of {sup 248} Cm has been measured. This measurement has been done by using a new experimental technique. This technique mainly depends on {gamma}-{gamma} coincidence using a very high resolution high purity germanium (HPGe) detector. 2 figs.

  10. Fission throughout the periodic table

    International Nuclear Information System (INIS)

    Moretto, L.G.; Wozniak, G.J.

    1989-04-01

    The dualistic view of fission and evaporation as two distinct compound nucleus processes is substituted with a unified view in which fission, complex fragment emission, and light particle evaporation are seen as different aspects of a single process. 47 refs., 22 figs

  11. A quantitative analysis of TIMS data obtained on the Learjet 23 at various altitudes

    Science.gov (United States)

    Jaggi, S.

    1992-01-01

    A series of Thermal Infrared Multispectral Scanner (TIMS) data acquisition flights were conducted on the NASA Learjet 23 at different altitudes over a test site. The objective was to monitor the performance of the TIMS (its estimation of the brightness temperatures of the ground scene) with increasing altitude. The results do not show any significant correlation between the brightness temperatures and the altitude. The analysis indicates that the estimation of the temperatures is a function of the accuracy of the atmospheric correction used for each altitude.

  12. Smart Mirrors for Photorefractive Control of Light with Tim Bunning, RX - Agile Filters Application

    Science.gov (United States)

    2016-11-08

    AFRL-AFOSR-UK-TR-2017-0008 Smart Mirrors for photorefractive control of light with Tim Bunning, RX-- Agile filters application Luciano De Sio...DATE (DD-MM-YYYY)      10-02-2017 2. REPORT TYPE Final 3. DATES COVERED (From - To) 01 Feb 2014 to 31 Jan 2016 4. TITLE AND SUBTITLE Smart Mirrors for...photorefractive control of light with Tim Bunning, RX-- Agile filters application 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-14-1-0050 5c.  PROGRAM

  13. Analysis of Eocene depositional environments - Preliminary TM and TIMS results, Wind River Basin, Wyoming

    Science.gov (United States)

    Stucky, Richard K.; Krishtalka, Leonard; Redline, Andrew D.; Lang, Harold R.

    1987-01-01

    Both Landsat TM and aircraft Thermal IR Multispectral Scanner (TIMS) data have been used to map the lithofacies of the Wind River Basin's Eocene physical and biological environments. Preliminary analyses of these data have furnished maps of a fault contact boundary and a complex network of fluvial ribbon channel sandstones. The synoptic view thereby emerging for Eocene fluvial facies clarifies the relationships of ribbon channel sandstones to fossil-bearing overbank/floodplain facies and certain peleosols. The utility of TM and TIMS data is thereby demonstrated.

  14. Progress in fission product nuclear data

    International Nuclear Information System (INIS)

    Lammer, M.

    1984-09-01

    This is the tenth issue of a report series on Fission Product Data, which informs us about all the activities in this field, which are planned, ongoing, or have recently been completed. The types of activities included are measurements, compilations and evaluations of: fission product yields (neutron induced and spontaneous fission), neutron reaction cross sections of fission products, data related to the radioactive decay of fission products, delayed neutron data of fission products, lumped fission product data (decay heat, absorption, etc.). There is also a section with recent references relative to fission product nuclear data

  15. Mechanisms of fission neutron emission

    International Nuclear Information System (INIS)

    Maerten, H.

    1991-01-01

    The time evolution in fission is the starting point for discussing not only the main mechanism of fission neutron emission, the evaporation from fully accelerated fragments, but also possible secondary ones connected with dynamical features of nuclear fission. ''Asymptotic'' conditions as relevant for describing the particle release from highly excited, rapidly moving fragments are defined. Corresponding statistical model approaches to fission neutron emission, based on the adequate consideration of the intricate fragment occurrence probability, reproduce most of the experimental data. The remarkable influence of fission modes on neutron observables is analyzed in the framework of a macroscopic-microscopic scission point model consistent with energy conservation. Finally, chances and deficiencies for solving the mechanism puzzle are summarized. (author). 87 refs, 21 figs

  16. Fifty years with nuclear fission

    International Nuclear Information System (INIS)

    Behrens, J.W.; Carlson, A.D.

    1989-01-01

    The news of the discovery of nuclear fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fifieth anniversary of its discovery by holding a topical meeting entitled, ''Fifty Years with Nuclear Fission,'' in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent development in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicated a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two fully days of sessions (April 27 and 28) at the main site of the NIST in Gaithersburg, Maryland. The wide range of topics covered in this Volume 1 by this topical meeting included plenary invited, and contributed sessions entitled: Preclude to the First Chain Reaction -- 1932 to 1942; Early Fission Research -- Nuclear Structure and Spontaneous Fission; 50 Years of Fission, Science, and Technology; Nuclear Reactors, Secure Energy for the Future; Reactors 1; Fission Science 1; Safeguards and Space Applications; Fission Data; Nuclear Fission -- Its Various Aspects; Theory and Experiments in Support of Theory; Reactors and Safeguards; and General Research, Instrumentation, and By-Product. The individual papers have been cataloged separately

  17. A polymorphism of the TIM-1 IgV domain: implications for the susceptibility to filovirus infection.

    Science.gov (United States)

    Kuroda, Makoto; Fujikura, Daisuke; Noyori, Osamu; Kajihara, Masahiro; Maruyama, Junki; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

    2014-12-12

    Filoviruses, including Ebola and Marburg viruses, cause severe hemorrhagic fever in humans and nonhuman primates with mortality rates of up to 90%. Human T-cell immunoglobulin and mucin domain 1 (TIM-1) is one of the host proteins that have been shown to promote filovirus entry into cells. In this study, we cloned TIM-1 genes from three different African green monkey kidney cell lines (Vero E6, COS-1, and BSC-1) and found that TIM-1 of Vero E6 had a 23-amino acid deletion and 6 amino acid substitutions compared with those of COS-1 and BSC-1. Interestingly, Vero E6 TIM-1 had a greater ability to promote the infectivity of vesicular stomatitis viruses pseudotyped with filovirus glycoproteins than COS-1-derived TIM-1. We further found that the increased ability of Vero E6 TIM-1 to promote virus infectivity was most likely due to a single amino acid difference between these TIM-1s. These results suggest that a polymorphism of the TIM-1 molecules is one of the factors that influence cell susceptibility to filovirus infection, providing a new insight into the molecular basis for the filovirus host range. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Endogenous Tim-1 (Kim-1) promotes T-cell responses and cell-mediated injury in experimental crescentic glomerulonephritis.

    Science.gov (United States)

    Nozaki, Yuji; Nikolic-Paterson, David J; Snelgrove, Sarah L; Akiba, Hisaya; Yagita, Hideo; Holdsworth, Stephen R; Kitching, A Richard

    2012-05-01

    The T-cell immunoglobulin mucin 1 (Tim-1) modulates CD4(+) T-cell responses and is also expressed by damaged proximal tubules in the kidney where it is known as kidney injury molecule-1 (Kim-1). We sought to define the role of endogenous Tim-1 in experimental T-cell-mediated glomerulonephritis induced by sheep anti-mouse glomerular basement membrane globulin acting as a planted foreign antigen. Tim-1 is expressed by infiltrating activated CD4(+) cells in this model, and we studied the effects of an inhibitory anti-Tim-1 antibody (RMT1-10) on immune responses and glomerular disease. Crescentic glomerulonephritis, proliferative injury, and leukocyte accumulation were attenuated following treatment with anti-Tim-1 antibodies, but interstitial foxp3(+) cell accumulation and interleukin-10 mRNA were increased. T-cell proliferation and apoptosis decreased in the immune system along with a selective reduction in Th1 and Th17 cellular responses both in the immune system and within the kidney. The urinary excretion and renal expression of Kim-1 was reduced by anti-Tim-1 antibodies reflecting diminished interstitial injury. The effects of anti-Tim-1 antibodies were not apparent in the early phase of renal injury, when the immune response to sheep globulin was developing. Thus, endogenous Tim-1 promotes Th1 and Th17 nephritogenic immune responses and its neutralization reduces renal injury while limiting inflammation in cell-mediated glomerulonephritis.

  19. How fission was discovered

    International Nuclear Information System (INIS)

    Fluegge, S.

    1989-01-01

    After the great survey of neutron induced radioactivity by Fermi and co-workers, the laboratories in Paris and Berlin-Dahlen tried to disentangle the complex results found in uranium. At that time neutron sources were small, activities low, and equipment very simple. Chemistry beyond uranium still was unknown. Hahn and Meitner believed to have observed three transuranic isomeric chains, a doubtful result even then. Early in 1938, Curie and Savic in Paris found an activity interpreted to be actinium, and Hahn and Meitner another to be radium. Both interpretations seemed impossible from energy considerations. Hahn and Strassmann, therefore, continued this work and succeeded to separate the new activity from radium. There remained no doubt that a barium isotope had been produced, the uranium nucleus splitting in the yet-unknown process we now call fission

  20. Increased Tim-3 expression alleviates liver injury by regulating macrophage activation in MCD-induced NASH mice.

    Science.gov (United States)

    Du, Xianhong; Wu, Zhuanchang; Xu, Yong; Liu, Yuan; Liu, Wen; Wang, Tixiao; Li, Chunyang; Zhang, Cuijuan; Yi, Fan; Gao, Lifen; Liang, Xiaohong; Ma, Chunhong

    2018-05-07

    As an immune checkpoint, Tim-3 plays roles in the regulation of both adaptive and innate immune cells including macrophages and is greatly involved in chronic liver diseases. However, the precise roles of Tim-3 in nonalcoholic steatohepatitis (NASH) remain unstated. In the current study, we analyzed Tim-3 expression on different subpopulations of liver macrophages and further investigated the potential roles of Tim-3 on hepatic macrophages in methionine and choline-deficient diet (MCD)-induced NASH mice. The results of flow cytometry demonstrated the significantly increased expression of Tim-3 on all detected liver macrophage subsets in MCD mice, including F4/80 + CD11b + , F4/80 + CD68 + , and F4/80 + CD169 + macrophages. Remarkably, Tim-3 knockout (KO) significantly accelerated MCD-induced liver steatosis, displaying higher serum ALT, larger hepatic vacuolation, more liver lipid deposition, and more severe liver fibrosis. Moreover, compared with wild-type C57BL/6 mice, Tim-3 KO MCD mice demonstrated an enhanced expression of NOX2, NLRP3, and caspase-1 p20 together with increased generation of IL-1β and IL-18 in livers. In vitro studies demonstrated that Tim-3 negatively regulated the production of reactive oxygen species (ROS) and related downstream pro-inflammatory cytokine secretion of IL-1β and IL-18 in macrophages. Exogenous administration of N-Acetyl-L-cysteine (NAC), a small molecular inhibitor of ROS, remarkably suppressed caspase-1 p20 expression and IL-1β and IL-18 production in livers of Tim-3 KO mice, thus significantly reducing the severity of steatohepatitis induced by MCD. In conclusion, Tim-3 is a promising protector in MCD-induced steatohepatitis by controlling ROS and the associated pro-inflammatory cytokine production in macrophages.

  1. Fifty years with nuclear fission

    International Nuclear Information System (INIS)

    Behrens, J.W.; Carlson, A.D.

    1989-01-01

    The news of the discovery of nucler fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fiftieth anniversary of its discovery by holding a topical meeting entitled, ''Fifty years with nuclear fission,'' in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent developments in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicating a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two full days of sessions (April 27 and 28) at the main sites of the NIST in Gaithersburg, Maryland. The wide range of topics covered by Volume 2 of this topical meeting included plenary invited, and contributed sessions entitled, Nuclear fission -- a prospective; reactors II; fission science II; medical and industrial applications by by-products; reactors and safeguards; general research, instrumentation, and by-products; and fission data, astrophysics, and space applications. The individual papers have been cataloged separately

  2. Science and technology with nuclear tracks in solids

    CERN Document Server

    Buford-Price, P

    2005-01-01

    Fission track dating has greatly expanded its usefulness to geology over the last 40 years. It is central to thermochronology—the use of shortened fission tracks to decipher the thermal history, movement, and provenance of rocks. When combined with other indicators, such as zircon color and (U–Th)/He, a range of temperatures from C to C can be studied. Combining fission track analysis with cosmogenic nuclide decay rates, one can study landscape development and denudation of passive margins. Technological applications have expanded from biological filters, radon mapping, and dosimetry to the use of ion track microtechnology in microlithography, micromachining by ion track etching, microscopic field emission tips, magnetic nanowires as magnetoresistive sensors, microfluidic devices, physiology of ion channels in single cells, and so on. In nuclear and particle physics, relatively insensitive glass detectors have been almost single-handedly responsible for our knowledge of cluster radioactivity, and plastic ...

  3. Nuclear fission and fission-product spectroscopy: 3. International workshop on nuclear fission and fission-product spectroscopy

    International Nuclear Information System (INIS)

    Goutte, Heloise; Fioni, Gabriele; Faust, Herbert; Goutte, Dominique

    2005-01-01

    The present book contains the proceedings of the third workshop in a series of workshops previously held in Seyssins in 1994 and 1998. The meeting was jointly organized by different divisions of CEA and two major international laboratories. In the opening address, Prof. B. Bigot, the French High Commissioner for Atomic Energy, outlined France's energy policy for the next few decades. He emphasized the continuing progress of nuclear fission in both technical and economic terms, allowing it to contribute to the energy needs of the planet even more in the future than it does today. Such progress implies a very strong link between fundamental and applied research based on experimental and theoretical approaches. The workshop gathered the different nuclear communities studying the fission process, including topics as the following: - nuclear fission experiments, - spectroscopy of neutron rich nuclei, - fission data evaluation, - theoretical aspects of nuclear fission, - and innovative nuclear systems and new facilities. The scientific program was suggested by an International Advisory Committee. About 100 scientists from 13 different countries attended the conference in the friendly working atmosphere of the Castle of Cadarache in the heart of the Provence. The proceedings of the workshop were divided into 11 sections addressing the following subject matters: 1. Cross sections and resonances (5 papers); 2. Fission at higher energies - I (5 papers); 3. Fission: mass and charge yields (4 papers); 4. Light particles and cluster emission (4 papers); 5. Spectroscopy of neutron rich nuclei (5 papers); 6. Resonances, barriers, and fission times (5 papers); 7. Fragment excitation and neutron emission (4 papers); 8. Mass and energy distributions (4 papers); 9. Needs for nuclear data and new facilities - I (4 papers); 10. Angular momenta and fission at higher Energies - II (3 papers); 11. New facilities - II (2 papers). A poster session of 8 presentations completed the workshop

  4. Servicing the first web server - Tim Berners-Lee's NeXT

    CERN Multimedia

    unknown, Association aBCM

    2009-01-01

    In August 2009 a team from the Association aBCM in Lausanne came to CERN to give the world's first web server a health check under the watchful eye of web pioneer Robert Cailliau. They took an image of the hard drive at this time, copies of which were given to Robert Cailliau and Tim Berners-Lee.

  5. Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

    Science.gov (United States)

    Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar E.; Baker, Erin S.; Liu, Tao; Smith, Richard D.; Fernandez-Lima, Francisco

    2017-09-01

    In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150-250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMS-CID-TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptide biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10-200 nM range, while simultaneously achieving discovery measurements of not initially targeted peptides as markers from the same proteins and, eventually, other proteins. [Figure not available: see fulltext.

  6. TIM-3 is not essential for development of airway inflammation induced by house dust mite antigens

    Directory of Open Access Journals (Sweden)

    Yoshihisa Hiraishi

    2016-10-01

    Conclusions: Our findings indicate that, in mice, TIM-3 is not essential for development of HDM-induced acute or chronic allergic airway inflammation, although it appears to be involved in reduced lymphocyte recruitment during HDM-induced chronic allergic airway inflammation.

  7. Consumerism, Activism, Intrinsic Motivation, and Balance: An Interview with Tim Kasser

    Science.gov (United States)

    Keeley, Jared

    2010-01-01

    A year after receiving his PhD in psychology from the University of Rochester, Tim Kasser accepted a position at Knox College, in Galesburg, Illinois, where he is currently professor of psychology. He regularly teaches psychology classes on personality, clinical and abnormal psychology, dreaming, and research methods, as well as an…

  8. Tim Allen, one of Hollywood's top comedy actors with Rolf Landua from CERN

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Tim Allen ('Galaxy Quest', 'For Richer and Poorer', 'The Santa Clause', Voice of 'Buzz Lightyear', in Toy Story 1 and 2), visited CERN in July 2000. He has a keen interest in modern physics. In his last book "I'm not really here" he contemplates the funny and the intriguing aspects of quantum physics in his daily life.

  9. The Filmmaker as Humanist: An Interview with Tim Robbins on the Making of "Cradle Will Rock".

    Science.gov (United States)

    Mason, Terrence C.

    2000-01-01

    Presents an interview with Tim Robbins that focuses on the making of the film "Cradle Will Rock." Robbins offers his perspectives on issues such as the power of art to convey important social messages and sources of violence in schools. Includes resources for teachers. (CMK)

  10. El De imaginibus caelestibus de Ibn al-Ḥātim

    Directory of Open Access Journals (Sweden)

    Oliveras, Marc

    2009-06-01

    Full Text Available K. Lippincott and D. Pingree published in 1987 a first Latin edition and English translation of the 15th bilingual Arabic-Latin De imaginibus caelestibus, written originally by the Andalusian Ibn al-Ḥātim in the 10th century. The paper presented here aims to complete the preceding one with an Arabic edition, Spanish translation and some interpretations on the possible sources of talismanic imagery. In this brief astromagic treatise, Ibn al-Ḥātim focuses on twenty eight talismans, related to the lunar mansions, and their magical properties.

    En 1987 K. Lippincott y D. Pingree publicaron una primera edición latina junto a una traducción inglesa del tratado bilingüe árabo-latino del s. XV De imaginibus caelestibus, escrito originariamente por el andalusí Ibn al-Ḥātim en el s. X. El trabajo que se presenta aquí pretende completar al precedente con una edición del texto árabe, su traducción al español y añadir algunas interpretaciones a las posibles fuentes de la imaginería talismánica. En este breve tratado de astromagia, Ibn al-Ḥātim se dedica principalmente a describir veintiocho talismanes, relacionados con las mansiones lunares, y sus propiedades mágicas.

  11. Suppression of TIM-1 predicates clinical efficacy of sublingual immunotherapy for allergic rhinitis in children.

    Science.gov (United States)

    Lin, Zhibin; Zhou, Lifeng; Luo, Xi; Xia, Wentong; Chen, Dehua; Xu, Rui; Wang, Jie; Luo, Renzhong; Xu, Geng; Li, Huabin

    2013-08-01

    To evaluate the clinical efficacy of sublingual immunotherapy (SLIT) with house-dust mite (HDM) extract and to examine the change of biomarkers (TIM-1, IL-5 and IL-10) after 6-month SLIT in children with allergic rhinitis (AR). One hundred and sixteen HDM-sensitized children with persistent AR were enrolled to assess the clinical efficacy of SLIT by determining the individual nasal symptom score (INSS) and total nasal symptom scores (TNSS) after 6-month SLIT. Moreover, the mRNA expression of TIM-1, IL-5 and IL-10 in peripheral blood mononuclear cells (PBMCs) was examined in 16 well-controlled and 12 uncontrolled AR patients using quantitative reverse transcription polymerase chain reaction (qRT-PCR). After 6-month SLIT, both TNSS and INSS scores were significantly decreased compared with the baseline value (p < 0.01). The rates for well-controlled, partly controlled and uncontrolled children were 43.1%, 32.8% and 24.1%, respectively. Accordingly, the mRNA levels of TIM-1 and IL-5 decreased significantly and IL-10 mRNA level increased significantly compared with the baseline value in well-controlled children (p < 0.05). Our findings suggest SLIT with HDM extract is effective and safe for AR children and TIM-1 may be considered as an indicator for evaluating the clinical efficacy of SLIT. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Onsite: A Residency with Tim Rollins/KOS. A Photo Essay.

    Science.gov (United States)

    Placky, Robert

    2000-01-01

    Presents a photo essay that visually narrates the workshop that took place in State College, Pennsylvania, from October 19-24, 1998 bringing together middle and high school students with Tim Rollins, who is a conceptual artist and educator, and Kids of Survival (KOS). (CMK)

  13. Active remodelling of the TIM23 complex during translocation of preproteins into mitochondria.

    Science.gov (United States)

    Popov-Celeketić, Dusan; Mapa, Koyeli; Neupert, Walter; Mokranjac, Dejana

    2008-05-21

    The TIM23 (translocase of the mitochondrial inner membrane) complex mediates translocation of preproteins across and their insertion into the mitochondrial inner membrane. How the translocase mediates sorting of preproteins into the two different subcompartments is poorly understood. In particular, it is not clear whether association of two operationally defined parts of the translocase, the membrane-integrated part and the import motor, depends on the activity state of the translocase. We established conditions to in vivo trap the TIM23 complex in different translocation modes. Membrane-integrated part of the complex and import motor were always found in one complex irrespective of whether an arrested preprotein was present or not. Instead, we detected different conformations of the complex in response to the presence and, importantly, the type of preprotein being translocated. Two non-essential subunits of the complex, Tim21 and Pam17, modulate its activity in an antagonistic manner. Our data demonstrate that the TIM23 complex acts as a single structural and functional entity that is actively remodelled to sort preproteins into different mitochondrial subcompartments.

  14. Gamma Radiation from Fission Fragments

    International Nuclear Information System (INIS)

    Higbie, Jack

    1969-10-01

    The gamma radiation from the fragments of the thermal neutron fission of 235 U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10 -10 sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass

  15. Energy partition in nuclear fission

    International Nuclear Information System (INIS)

    Ruben, A.; Maerten, H.; Seeliger, D.

    1990-01-01

    A scission point model (two spheroid model TSM) including semi-empirical temperature-dependent shell correction energies for deformed fragments at scission is presented. It has been used to describe the mass-asymmetry-dependent partition of the total energy release on both fragments from spontaneous and induced fission. Characteristic trends of experimental fragment energy and neutron multiplicity data as function of incidence energy in the Th-Cf region of fissioning nuclei are well reproduced. Based on model applications, information on the energy dissipated during the descent from second saddle of fission barrier to scission point have been deduced. (author). 39 refs, 13 figs

  16. Gamma Radiation from Fission Fragments

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-10-15

    The gamma radiation from the fragments of the thermal neutron fission of {sup 235}U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10{sup -10} sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass.

  17. Fission-product source terms

    International Nuclear Information System (INIS)

    Lorenz, R.A.

    1981-01-01

    This presentation consists of a review of fission-product source terms for light water reactor (LWR) fuel. A source term is the quantity of fission products released under specified conditions that can be used to calculate the consequences of the release. The source term usually defines release from breached fuel-rod cladding but could also describe release from the primary coolant system, the reactor containment shell, or the site boundary. The source term would be different for each locality, and the chemical and physical forms of the fission products could also differ

  18. The spectroscopy of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.R. [Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    High-resolution measurements on {gamma} rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author) 24 refs., 8 figs., 1 tab.

  19. The spectroscopy of fission fragments

    International Nuclear Information System (INIS)

    Phillips, W.R.

    1998-01-01

    High-resolution measurements on γ rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author)

  20. Solid state track recorder measurements in the poolside critical assembly

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Gold, R.; Roberts, J.H.

    1979-01-01

    Fission rate measurements using solid state track recorders (SSTR) have been performed at the PCA. A schematic representation of a cross-section of the PCA is shown. Fission rates were measured in the pressure vessel simulator at the T/4, T/2 and 3T/4 positions and in the void box (VB). SSTR measurements were carried out with 232 Th, 235 U (bare and cadmium covered), 238 U and 237 Np fissionable deposits. Midplane only measurements were carried out for 235 U and 237 Np, while 5 axial locations at 1/4T and 1/2T and 3 axial locations at 3/4T and in the VB were sampled for 232 Th and 238 U. The HEDL SSTR fission rate measurements reported herein for both configurations together with NBS and CEN/SCK fission chamber measurements will be used to establish absolute and relative fission reaction rates, and ratios for the PCA pressure vessel Benchmark Facility

  1. T-bet-mediated Tim-3 expression dampens monocyte function during chronic hepatitis C virus infection.

    Science.gov (United States)

    Yi, Wenjing; Zhang, Peixin; Liang, Yan; Zhou, Yun; Shen, Huanjun; Fan, Chao; Moorman, Jonathan P; Yao, Zhi Q; Jia, Zhansheng; Zhang, Ying

    2017-03-01

    Hepatitis C virus (HCV) induces a high rate of chronic infection via dysregulation of host immunity. We have previously shown that T-cell immunoglobulin and mucin domain protein-3 (Tim-3) is up-regulated on monocyte/macrophages (M/Mφ) during chronic HCV infection; little is known, however, about the transcription factor that controls its expression in these cells. In this study, we investigated the role of transcription factor, T-box expressed in T cells (T-bet), in Tim-3 expression in M/Mφ in the setting of HCV infection. We demonstrate that T-bet is constitutively expressed in resting CD14 + M/Mφ in the peripheral blood. M/Mφ from chronically HCV-infected individuals exhibit a significant increase in T-bet expression that positively correlates with an increased level of Tim-3 expression. Up-regulation of T-bet is also observed in CD14 + M/Mφ incubated with HCV + Huh7.5 cells, as well as in primary M/Mφ or monocytic THP-1 cells exposed to HCV core protein in vitro, which is reversible by blocking HCV core/gC1qR interactions. Moreover, the HCV core-induced up-regulation of T-bet and Tim-3 expression in M/Mφ can be abrogated by incubating the cells with SP600125 - an inhibitor for the c-Jun N-terminal kinase (JNK) signalling pathway. Importantly, silencing T-bet gene expression decreases Tim-3 expression and enhances interleukin-12 secretion as well as signal transducer and activator of transcription 1 phosphorylation. These data suggest that T-bet, induced by the HCV core/gC1qR interaction, enhances Tim-3 expression via the JNK pathway, leading to dampened M/Mφ function during HCV infection. These findings reveal a novel mechanism for Tim-3 regulation via T-bet during HCV infection, providing new targets to combat this global epidemic viral disease. © 2016 John Wiley & Sons Ltd.

  2. Diallyl phthalate (DAP) solid state nuclear track detector

    CERN Document Server

    Koguchi, Y; Ashida, T; Tsuruta, T

    2003-01-01

    Diallyl phthalate (DAP) solid state nuclear track detector is suitable for detecting heavy ions such as fission fragments, because it is insensitive to right ions such as alpha particles and protons. Detection efficiency of fission tracks is about 100%, which is unaffected under conditions below 240degC lasting for 1h or below 1 MGy of gamma-ray irradiation. Optimum etching condition for the DAP detector for detection of fission fragments is 2-4 h using 30% KOH aqueous solution at 90degC or 8-15 min using PEW-65 solution at 60degC. DAP detector is useful in detecting induced fission tracks for dating of geology or measuring intense heavy ions induced by ultra laser plasma. The fabrication of copolymers of DAP and CR-39 makes it possible to control the discrimination level for detection threshold of heavy ions. (author)

  3. Fission dynamics with systems of intermediate fissility

    Indian Academy of Sciences (India)

    results concerning nuclear dissipation and fission time-scale obtained from several of these studies. In particular ... alent to the assumption that fission is delayed, namely, that the fission probability is not .... parameters to be adjusted on the experimental data. ..... (b) Time distribution of all fission events for the 132Ce nucleus.

  4. Reversibility and two state behaviour in the thermal unfolding of oligomeric TIM barrel proteins.

    Science.gov (United States)

    Romero-Romero, Sergio; Costas, Miguel; Rodríguez-Romero, Adela; Alejandro Fernández-Velasco, D

    2015-08-28

    Temperature is one of the main variables that modulate protein function and stability. Thermodynamic studies of oligomeric proteins, the dominant protein natural form, have been often hampered because irreversible aggregation and/or slow reactions are common. There are no reports on the reversible equilibrium thermal unfolding of proteins composed of (β/α)8 barrel subunits, albeit this "TIM barrel" topology is one of the most abundant and versatile in nature. We studied the eponymous TIM barrel, triosephosphate isomerase (TIM), belonging to five species of different bacterial taxa. All of them were found to be catalytically efficient dimers. The three-dimensional structure of four enzymes was solved at high/medium resolution. Irreversibility and kinetic control were observed in the thermal unfolding of two TIMs, while for the other three the thermal unfolding was found to follow a two-state equilibrium reversible process. Shifts in the global stability curves of these three proteins are related to the organismal temperature range of optimal growth and modulated by variations in maximum stability temperature and in the enthalpy change at that temperature. Reversibility appears to correlate with the low isoelectric point, the absence of a residual structure in the unfolded state, small cavity volume in the native state, low conformational stability and a low melting temperature. Furthermore, the strong coupling between dimer dissociation and monomer unfolding may reduce aggregation and favour reversibility. It is therefore very thought-provoking to find that a common topological ensemble, such as the TIM barrel, can unfold/refold in the Anfinsen way, i.e. without the help of the cellular machinery.

  5. Geochronology and geochemistry by nuclear tracks method: some utilization examples in geologic applied

    International Nuclear Information System (INIS)

    Poupeau, G.; Soliani Junior, E.

    1988-01-01

    This article discuss some applications of the 'nuclear tracks method' in geochronology, geochemistry and geophysic. In geochronology, after rapid presentation of the dating principles by 'Fission Track' and the kinds of geological events mensurable by this method, is showed some application in metallogeny and in petroleum geolocy. In geochemistry the 'fission tracks' method utilizations are related with mining prospecting and uranium prospecting. In geophysics an important application is the earthquake prevision, through the Ra 222 emanations continous control. (author) [pt

  6. Neutron activation analysis of uranium by means of electrochemical etching of tracks in lawsan detectors

    International Nuclear Information System (INIS)

    Kim Son Chun; Chuburkov, Yu.T.; Zvara, I.I.

    1982-01-01

    The method of neutron activation analysis of uranium in natural and artificial materials using track lavsan detectors of fission fragments has been developed. The method of electrochemical etching (etching reagent NaOH) of fragment tracks in lavsan is improved. Using statistical method of experiment planning the equation, describing the dependence of diometer value of fission fragment tracks on parameters of etching process, is obtained. The analysis sensitivity is 10 - 7 g/g - 10 - 8 g/g

  7. Fission gas in thoria

    Energy Technology Data Exchange (ETDEWEB)

    Kuganathan, Navaratnarajah, E-mail: n.kuganathan@imperial.ac.uk [Department of Materials, Faculty of Engineering, Imperial College, London, SW7 2AZ (United Kingdom); Ghosh, Partha S. [Material Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Galvin, Conor O.T. [Department of Materials, Faculty of Engineering, Imperial College, London, SW7 2AZ (United Kingdom); Arya, Ashok K. [Material Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Dutta, Bijon K. [Homi Bhabha National Institute, Trombay, Mumbai 400 094 (India); Dey, Gautam K. [Material Science Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Grimes, Robin W. [Department of Materials, Faculty of Engineering, Imperial College, London, SW7 2AZ (United Kingdom)

    2017-03-15

    The fission gases Xe and Kr, formed during normal reactor operation, are known to degrade fuel performance, particularly at high burn-up. Using first-principles density functional theory together with a dispersion correction (DFT + D), in ThO{sub 2} we calculate the energetics of neutral and charged point defects, the di-vacancy (DV), different neutral tri-vacancies (NTV), the charged tetravacancy (CTV) defect cluster geometries and their interaction with Xe and Kr. The most favourable incorporation point defect site for Xe or Kr in defective ThO{sub 2} is the fully charged thorium vacancy. The lowest energy NTV in larger supercells of ThO{sub 2} is NTV3, however, a single Xe atom is most stable when accommodated within a NTV1. The di-vacancy (DV) is a significantly less favoured incorporation site than the NTV1 but the CTV offers about the same incorporation energy. Incorporation of a second gas atom in a NTV is a high energy process and more unfavourable than accommodation within an existing Th vacancy. The bi-NTV (BNTV) cluster geometry studied will accommodate one or two gas atoms with low incorporation energies but the addition of a third gas atom incurs a high energy penalty. The tri-NTV cluster (TNTV) forms a larger space which accommodates three gas atoms but again there is a penalty to accommodate a fourth gas atom. By considering the energy to form the defect sites, solution energies were generated showing that in ThO{sub 2−x} the most favourable solution equilibrium site is the NTV1 while in ThO{sub 2} it is the DV. - Highlights: • We have considered Xe and Kr in point defects and defect clusters (neutral and charged) using Density Functional Theory (DFT) with a dispersion correction. • The most favourable charge state for a point defect (vacancy or interstitial) is that with full ionic charge and we have found that in all cases gas atoms occupy the fully charged vacancy sites. • The number of fission gas atoms accommodated in ThO{sub 2} is

  8. Chemical effects of fission recoils

    International Nuclear Information System (INIS)

    Meisels, G.G.; Freeman, J.P.; Gregory, J.P.; Richardson, W.C.; Sroka, G.J.

    1978-01-01

    The production of nitrogen from nitrous oxide at high density was employed to investigate the energy deposition efficiency of fission recoils produced from fission of U 235 in uranium-palladium foils clad with platinum. Nitrogen production varied linearly with fission recoil dose from 1.1 x 10 20 to 9.0 x 10 20 eV, and was independent of density between 12.5 and 127.5 g l -1 N 2 O. 16.2 +- 0.8% of the fission recoil energy was deposited external to the foil. Electron microprobe analysis showed some unevenness of new foil and polymer buildup on the surface after irradiation of ethylene-oxygen mixtures. Subsequent irradiation in the presence of nitrous oxide restored some of the original efficiency. This is ascribed to chemical oxidation of the polymer induced by reactive intermediates produced from nitrous oxide. (author)

  9. Extraction chromatography of fission products

    International Nuclear Information System (INIS)

    Bonnevie-Svendsen, M.; Goon, K.

    1978-01-01

    Various cases of using extraction chromatography during analysis of fission products are reviewed. The use of the extraction chromatography method is considered while analysing reprocessed products of nuclear fuel for quantitative radiochemical analysis and control of fission product and actinoide separation during extraction and their chemical state in production solutions. The method is used to obtain pure fractions of typical burnup monitors (neodymium, molybdenum, cerium, cesium, europium, lanthanides) during determination of nuclear fuel burnup degree. While studying the nature of nuclear reactions the method is used to separate quickly short-life isotopes, to purify β-radiator fractions before measuring their half-life periods, to enrich isotopes forming with low output during fission. Examples of using extraction chromatography are given to separate long half-life or stable fission products from spent solutions, to control environment object contamination

  10. Physics and chemistry of fission

    International Nuclear Information System (INIS)

    1979-01-01

    Full text: In the pleasant and hospitable atmosphere of the Kernforschungsanlage Juelich in the Federal Republic of Germany, the IAEA symposium on the Physics and Chemistry of Fission took place. Almost 200 scientists attended, 154 abstracts were submitted, and 57 papers presented, but more important than the numbers was the quality of the contributions and the progress reported at the symposium. The neutron was discovered almost 50 years ago; 40 years ago the idea of nuclear fission was born. Since then, a number of laboratories have worked hard to explain the phenomenon of fission One would expect that by now scientists would know exactly what happens in a nucleus before and during the process of fission, particularly as there are hundreds of power and research reactors in operation, and fission of uranium isotopes is the basis of their functioning. At first glance, fission seems a simple process: a neutron hits and penetrates the uranium nucleus which becomes excited, i.e. has a surplus of energy. One way to get rid of this energy is for the nucleus to split into two parts; additional products of this process are energy and more neutrons. Nature, however, seems to dislike such straightforward explanations. In the case of fission, scientists have observed a number of phenomena which disagree with a simple model. Sometimes, a nucleus will split into two parts without being 'attacked' by a neutron; this spontaneous fission opens up a new line of fission research and several contributions at the symposium reported on sophisticated experiments designed to unravel some of its specific details. Sometimes, a fissioning nucleus will emit another particle: ternary fission has become a powerful tool for studying the properties of nuclei during the fission process. For the scientist, it is fascinating to observe how the nucleus behaves during fission. They invent models which are supposed to reproduce the most probable course of events leading to fission. In one of these

  11. International handling of fissionable material

    International Nuclear Information System (INIS)

    1975-01-01

    The opinion of the ministry for foreign affairs on international handling of fissionable materials is given. As an introduction a survey is given of the possibilities to produce nuclear weapons from materials used in or produced by power reactors. Principles for international control of fissionable materials are given. International agreements against proliferation of nuclear weapons are surveyed and methods to improve them are proposed. (K.K.)

  12. Theory of nuclear fission: a review

    International Nuclear Information System (INIS)

    Mosel, U.

    1976-01-01

    General properties of nuclear fission are reviewed and related to our present knowledge of fission theory. For this purpose the basic reasons for the shape of the fission barriers are discussed and their consequences compared with experimental results on barrier shapes and structures. Special emphasis is put on the asymmetry of the fission barriers and mass-distributions and its relation to the shells of the nascent fragment shells. Finally the problem of calculating fission cross sections is discussed

  13. TIM-1 glycoprotein binds the adhesion receptor P-selectin and mediates T cell trafficking during inflammation and autoimmunity

    Science.gov (United States)

    Angiari, Stefano; Donnarumma, Tiziano; Rossi, Barbara; Dusi, Silvia; Pietronigro, Enrica; Zenaro, Elena; Della Bianca, Vittorina; Toffali, Lara; Piacentino, Gennj; Budui, Simona; Rennert, Paul; Xiao, Sheng; Laudanna, Carlo; Casasnovas, Jose M.; Kuchroo, Vijay K.; Constantin, Gabriela

    2014-01-01

    SUMMARY Selectins play a central role in leukocyte trafficking by mediating tethering and rolling on vascular surfaces. Here we have reported that T cell immunoglobulin and mucin domain 1 (TIM-1) is a P-selectin ligand. We have shown that human and murine TIM-1 binds to P-selectin, and that TIM-1 mediates tethering and rolling of T helper-1 (Th1) and Th17, but not Th2 and regulatory T cells on P-selectin. Th1 and Th17 cells lacking the TIM-1 mucin domain showed reduced rolling in thrombin-activated mesenteric venules and inflamed brain microcirculation. Inhibition of TIM-1 had no effect on naive T cell homing, but reduced T cell recruitment in a skin hypersensitivity model and blocked experimental autoimmune encephalomyelitis. Uniquely, the TIM-1 IgV domain was also required for P-selectin binding. Our data demonstrate that TIM-1 is a major P-selectin ligand with a specialized role in T cell trafficking during inflammatory responses and the induction of autoimmune disease. PMID:24703780

  14. Spontaneous fission of 259Md

    International Nuclear Information System (INIS)

    Hulet, E.K.; Wild, J.F.; Lougheed, R.W.; Baisden, P.A.; Landrum, J.H.; Dougan, R.J.; Mustafa, M.; Ghiorso, A.; Nitschke, J.M.

    1979-01-01

    The mass and kinetic energy distributions of fission fragments from the spontaneous fission of th newly discovered nuclide 259 Md were obtained. 259 Md was identified as the E. C. daughter of 259 No, and was found to decay entirely (> 95%) by spontaneous fission with a 95-min half-life. From the kinetic energies measured for 397 pairs of coincident fragments, a mass distribution was derived that is symmetric with sigma = 13 amu. 259 Md, together with 258 Fm and 259 Fm, form a select group of three nuclides whose mass division in spontaneous fission is highly symmetric. Unlike the total-kinetic-energy (TKE) distributions of 258 Fm and 259 Fm, which peak at approx. = to 240 MeV, this distribution for 259 Md is broad and is 50 MeV lower in energy. Analysis of the mass and energy distributions shows that events near mass symmetry also exhibit a broad TKE distribution, with one-third of the symmetric events having TKEs less than 200 MeV. The associated of low TKEs with symmetric mass division in the fission of very heavy actinides is anomalous and inconsistent with theories based upon the emergence of fragment shells near the scission point. Either three-body fragmentation or peculiar fragment shapes are assumed as the cause for the large consumption of Coulomb energy observed for a significant fraction of symmetric fissions in 259 Md. 6 figures

  15. A stochastic approach to fission

    International Nuclear Information System (INIS)

    Boilley, D.; Suraud, E.; Abe, Yasuhisa

    1992-01-01

    A microscopically derived Langevin equation is applied to thermally induced nuclear fission. An important memory effect is pointed out. A strong friction coefficient, calculated from microscopic quantities, tends to decrease the stationary limit of the fission rate and to increase the transient time. Fission was described as a diffusion over a barrier of a collective variable, and a Langevin Equation (LE) was used to study the phenomenon. A study of the stationary flow over the saddle point with a Fokker-Planck Equation (FPE), equivalent to the LE was used to give formula for the stationary fission rate (or reaction rate for the chemistry applications). More recently, a complete study of the fission process was performed numerically with both FPE and LE. A long transient time, that could allow more pre-scission neutrons to evaporate, was pointed out. The derivation of this new LE is recalled, followed by the description of the memory dependence and by the effect of a large friction coefficient on the fission rate. (author) 6 refs., 3 figs

  16. Modelling isothermal fission gas release

    International Nuclear Information System (INIS)

    Uffelen, P. van

    2002-01-01

    The present paper presents a new fission gas release model consisting of two coupled modules. The first module treats the behaviour of the fission gas atoms in spherical grains with a distribution of grain sizes. This module considers single atom diffusion, trapping and fission induced re-solution of gas atoms associated with intragranular bubbles, and re-solution from the grain boundary into a few layers adjacent to the grain face. The second module considers the transport of the fission gas atoms along the grain boundaries. Four mechanisms are incorporated: diffusion controlled precipitation of gas atoms into bubbles, grain boundary bubble sweeping, re-solution of gas atoms into the adjacent grains and gas flow through open porosity when grain boundary bubbles are interconnected. The interconnection of the intergranular bubbles is affected both by the fraction of the grain face occupied by the cavities and by the balance between the bubble internal pressure and the hydrostatic pressure surrounding the bubbles. The model is under validation. In a first step, some numerical routines have been tested by means of analytic solutions. In a second step, the fission gas release model has been coupled with the FTEMP2 code of the Halden Reactor Project for the temperature distribution in the pellets. A parametric study of some steady-state irradiations and one power ramp have been simulated successfully. In particular, the Halden threshold for fission gas release and two simplified FUMEX cases have been computed and are summarised. (author)

  17. Status of fission power

    International Nuclear Information System (INIS)

    Levenson, M.

    1977-01-01

    Fission energy is reviewed from the viewpoints of technology, economics, politics, manufacturers, consumers, and foreign countries. Technically, the reactor program is operating and the light water reactor industry shows signs of maturing, although recent business has been disappointing. Marketing of gas-cooled reactors depends, not on technical, but economic and political issues. Liquid metal fast breeder reactors have been demonstrated worldwide, while the gas-cooled fast breeder remains an undemonstrated option. Nuclear plants, currently costing the same as coal plants with scrubbers, are the cheapest option for utilities because most of the cost is imbedded. The defeat of nuclear initiatives in seven states indicates that public feeling is not as anti-nuclear as opponents to nuclear power claim. The harshness of last winter demonstrated the advantages of a power source that is not so sensitive to the weather for reliable operation and transport, as well as low cost energy. Other nations are proceeding to build a nuclear capability, which the U.S. may jeopardize because of concerns about the fuel cycle, nuclear waste disposal, uranium reserves, and nuclear proliferation

  18. Radiochemistry and the Study of Fission

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-14

    These are slides from a lecture given at UC Berkeley. Radiochemistry has been used to study fission since its discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution. The following topics are covered: In the beginning: the discovery of fission; forensics using fission products: what can be learned from fission products, definitions of R-values and Q-values, fission bases, K-factors and fission chambers, limitations; the neutron energy dependence of the mass yield distribution (the two mode fission hypothesis); the influence of nuclear structure on the mass yield distribution. In summary: Radiochemistry has been used to study fission since its discovery. Radiochemical measurement of fission product yields have provided the highest precision data for developing fission models and for nuclear forensics. The two-mode fission hypothesis provides a description of the neutron energy dependence of the mass yield curve. However, data is still rather sparse and more work is needed near second and third chance fission. Radiochemical measurements have provided evidence for the importance of nuclear states in the compound nucleus in predicting the mass yield curve in the resonance region.

  19. Radiochemistry and the Study of Fission

    International Nuclear Information System (INIS)

    Rundberg, Robert S.

    2016-01-01

    These are slides from a lecture given at UC Berkeley. Radiochemistry has been used to study fission since its discovery. Radiochemical methods are used to determine cumulative mass yields. These measurements have led to the two-mode fission hypothesis to model the neutron energy dependence of fission product yields. Fission product yields can be used for the nuclear forensics of nuclear explosions. The mass yield curve depends on both the fuel and the neutron spectrum of a device. Recent studies have shown that the nuclear structure of the compound nucleus can affect the mass yield distribution. The following topics are covered: In the beginning: the discovery of fission; forensics using fission products: what can be learned from fission products, definitions of R-values and Q-values, fission bases, K-factors and fission chambers, limitations; the neutron energy dependence of the mass yield distribution (the two mode fission hypothesis); the influence of nuclear structure on the mass yield distribution. In summary: Radiochemistry has been used to study fission since its discovery. Radiochemical measurement of fission product yields have provided the highest precision data for developing fission models and for nuclear forensics. The two-mode fission hypothesis provides a description of the neutron energy dependence of the mass yield curve. However, data is still rather sparse and more work is needed near second and third chance fission. Radiochemical measurements have provided evidence for the importance of nuclear states in the compound nucleus in predicting the mass yield curve in the resonance region.

  20. Preparation and characterization of a novel nanobody against T-cell immunoglobulin and mucin-3 (TIM-3

    Directory of Open Access Journals (Sweden)

    Vida Homayouni

    2016-11-01

    Full Text Available Objective(s: As T-cell immunoglobulin and mucin domain 3 (TIM-3 is an immune regulatory molecule; its blocking or stimulating could alter the pattern of immune response towards a desired condition. Based on the unique features of nanobodies, we aimed to construct an anti-TIM-3 nanobody as an appropriate tool for manipulating immune responses for future therapeutic purposes. Materials and Methods:We immunized a camel with TIM-3 antigen and then, synthesized a VHH phagemid library from its B cell’s transcriptome using nested PCR. Library selection against TIM-3antigen was performed in three rounds of panning. Using phage-ELISA, the most reactive colonies were selected for sub-cloning in soluble protein expression vectors. The Nanobody was purified and confirmed with a nickel-nitrilotriacetic acid (Ni-NTA column, SDS-PAGE and Western blotting. A flowcytometric analysis was performed to analyze the binding and biologic activities of theTIM-3 specific nanobody with TIM-3 expressing HL-60 and HEK cell lines. Results:Specific 15kD band representing for nanobody was observed on the gel and confirmed with Western blotting. The nanobody showed significant specific immune-reactivity against TIM-3 with a relatively high binding affinity. The nanobody significantly suppressed the proliferation of TIM-3 expressing HL-60 cell line. Conclusion: Finally, we successfully prepared a functional anti-humanTIM-3 specific nanobody with a high affinity and an anti-proliferative activity on an AML cell line in vitro.