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Salabura P, Adamczewski-Musch J, Arnoldi-Meadows B, Belounnas A, Belyaev A, Blanco A, Blume C, Böhmer M, Borisenko S, Chlad L, Chudoba P, Ciepał I, Dittert D, Dreyer J, Esmail W, Dürr M, Fabbietti L, Fateev S, Fonte P, Friese J, Fröhlich I, Förtsch J, Galatyuk T, Gernhäuser R, Golosov O, Golubeva M, Greifenhagen R, Guber F, Gumberidze M, Harabasz S, Hensch R, Höhne C, Holzmann R, Huck H, Ierusalimov A, Ivashkin A, Kämpfer B, Kampert KH, Kardan B, Koenig I, Koenig W, Kornakov G, Kornas F, Kotte R, Kozela A, Kres I, Kuboś J, Kugler A, Kulesa P, Ladygin V, Lalik R, Lebedev A, Lebedev S, Linev S, Lopes L, Lorenz M, Lykasov G, Mahmoud T, Malige A, Markert J, Matulewicz T, Maurus S, Metag V, Michel J, Morozov S, Müntz C, Naumann L, Nowakowski K, Otto JH, Patel V, Pauly C, Pechenov V, Pechenova O, Petukhov O, Pfeifer D, Piasecki K, Pietraszko J, Prozorov A, Przygoda W, Pysz K, Ramstein B, Rathod N, Reshetin A, Ritman L, Rodriguez-Ramos P, Rost A, Salabura P, Scozzi F, Seck F, Selyuzhenkov I, Shabanov I, Singh US, Smyrski J, Spies S, Ströbele H, Stroth J, Stumm J, Svoboda O, Szala M, Tlusty P, Traxler M, Ungethüm C, Vazquez-Doce O, Wagner V, Weber A, Wendisch C, Wiebusch M, Wintz P, Wirth J, Zhilin A, Zumbruch P. Exploring time like tranistions in pp, πp and AA reactions with HADES. EPJ Web Conf 2020. [DOI: 10.1051/epjconf/202024101013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Radiative transition of an excited baryon to a nucleon with emission of a virtual massive photon converting to dielectron pair (Dalitz decays) provides important information about baryon-photon coupling at low q2 in timelike region. A prominent enhancement in the respective electromagnetic transition Form Factors (etFF) at q2 near vector mesons ρ/ω poles has been predicted by various calculations reflecting strong baryon-vector meson couplings. The understanding of these couplings is also of primary importance for the interpretation of the emissivity of QCD matter studied in heavy ion collisions via dilepton emission. Dedicated measurements of baryon Dalitz decays in proton-proton and pion-proton scattering with HADES detector at GSI/FAIR are presented and discussed. The relevance of these studies for the interpretation of results obtained from heavy ion reactions is elucidated on the example of the HADES results.
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Gross M, Engel J, Good J, Huck H, Isaev I, Koss G, Krasilnikov M, Lishilin O, Loisch G, Renier Y, Rublack T, Stephan F, Brinkmann R, Martinez de la Ossa A, Osterhoff J, Malyutin D, Richter D, Mehrling T, Khojoyan M, Schroeder CB, Grüner F. Observation of the Self-Modulation Instability via Time-Resolved Measurements. Phys Rev Lett 2018; 120:144802. [PMID: 29694120 DOI: 10.1103/physrevlett.120.144802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Indexed: 06/08/2023]
Abstract
Self-modulation of an electron beam in a plasma has been observed. The propagation of a long (several plasma wavelengths) electron bunch in an overdense plasma resulted in the production of multiple bunches via the self-modulation instability. Using a combination of a radio-frequency deflector and a dipole spectrometer, the time and energy structure of the self-modulated beam was measured. The longitudinal phase space measurement showed the modulation of a long electron bunch into three bunches with an approximately 200 keV/c amplitude momentum modulation. Demonstrating this effect is a breakthrough for proton-driven plasma accelerator schemes aiming to utilize the same physical effect.
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Affiliation(s)
- M Gross
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - J Engel
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - J Good
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - H Huck
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - I Isaev
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - G Koss
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - M Krasilnikov
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - O Lishilin
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - G Loisch
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - Y Renier
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - T Rublack
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - F Stephan
- Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, 15738 Zeuthen, Germany
| | - R Brinkmann
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - A Martinez de la Ossa
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
- Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - J Osterhoff
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - D Malyutin
- Helmholtz-Zentrum Berlin für Materialien & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - D Richter
- Helmholtz-Zentrum Berlin für Materialien & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - T Mehrling
- Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - M Khojoyan
- LLR (Laboratoire Leprince-Ringuet), CNRS and Ecole Polytechnique, Palaiseau UMR7638, France
| | - C B Schroeder
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - F Grüner
- Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- Center for Free-Electron Laser Science, Notkestrasse 85, 22607 Hamburg, Germany
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Lohaiza F, Velasco H, Juri Ayub J, Rizzotto M, Di Gregorio DE, Huck H, Valladares DL. Annual variation of (7)Be soil inventory in a semiarid region of central Argentina. J Environ Radioact 2014; 130:72-77. [PMID: 24487256 DOI: 10.1016/j.jenvrad.2014.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 01/09/2014] [Accepted: 01/13/2014] [Indexed: 06/03/2023]
Abstract
Reliable information on environmental radionuclides atmospheric entrance, and their distribution along the soil profile, is a necessary condition for using these soil and sediment tracers to investigate key environmental processes. To address this need, (7)Be content in rainwater and the wet deposition in a semiarid region at San Luis Province, Argentina, were studied. Following these researches, in the same region, we have assessed the (7)Be content along a soil profile, during 2.5 years from September 2009 to January 2012. As expected, the specific activity values in soil samples in the wet period (November-April) were higher than in the dry period (May-October). During the investigated period (2009 - beginning 2012) and for all sampled points, the maximum value of the (7)Be specific activity (Bq kg(-1)) was measured at the surface level. A typical decreasing exponential function of (7)Be areal activity (Bq m(-2)) with soil mass depth (kg m(-2)) was found and the key distribution parameters were determined for each month. The minimum value of areal activity was 51 Bq m(-2) in August, and the maximum was 438 Bq m(-2) in February. The relaxation mass depth ranges from 2.9 kg m(-2) in March to 1.3 kg m(-2) in August. (7)Be wet deposition can explain in a very significant proportion the (7)Be inventory in soil. During the period of winds in the region (September and October), the (7)Be content in soil was greater than the expected contribution from wet deposition, situation that is compatible with a higher relative contribution of dry deposition at this period of the year.
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Affiliation(s)
- F Lohaiza
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejército de los Andes 950, D5700HHW San Luis, Argentina
| | - H Velasco
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejército de los Andes 950, D5700HHW San Luis, Argentina.
| | - J Juri Ayub
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejército de los Andes 950, D5700HHW San Luis, Argentina
| | - M Rizzotto
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejército de los Andes 950, D5700HHW San Luis, Argentina
| | - D E Di Gregorio
- Departamento de Física, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 San Martín, Provincia de Buenos Aires, Argentina; Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Martín de Irigoyen 3100, 1650 San Martín, Provincia de Buenos Aires, Argentina
| | - H Huck
- Departamento de Física, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 San Martín, Provincia de Buenos Aires, Argentina; Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Martín de Irigoyen 3100, 1650 San Martín, Provincia de Buenos Aires, Argentina
| | - D L Valladares
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejército de los Andes 950, D5700HHW San Luis, Argentina
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Ayub JJ, Lohaiza F, Velasco H, Rizzotto M, Di Gregorio D, Huck H. Assessment of ⁷Be content in precipitation in a South American semi-arid environment. Sci Total Environ 2012; 441:111-116. [PMID: 23137975 DOI: 10.1016/j.scitotenv.2012.09.079] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 09/26/2012] [Accepted: 09/29/2012] [Indexed: 06/01/2023]
Abstract
There are two naturally occurring radiogenic isotopes of beryllium, ⁷Be and ¹⁰Be. These are produced when cosmic radiation interacts with oxygen and nitrogen in the atmosphere. After production, these radionuclides are input to ecosystems through wet and dry deposition. In recent years ⁷Be and ¹⁰Be have proved to be powerful tools for studying dynamic processes that occur on the surface of the earth. We measured the ⁷Be content in precipitation at a semiarid location in central Argentina. From November 2006 to March 2009, 68 precipitation events were collected. Measured ⁷Be content ranged from 0.7±0.4 Bq L⁻¹ to 3.2±0.7 Bq L⁻¹, with a mean of 1.7 Bq L⁻¹ ±0.6 Bq L⁻¹. Beryllium-7 content of rainfall did not show clear relationships with amount of rainfall (mm), mean intensity (mm h⁻¹) or duration (h⁻¹), or elapsed time between events (day). The general results indicate that for the typical range of precipitation there was no atmospheric washout and that the reload of the atmosphere is not a relevant factor, but when the amount of precipitation is very high washout may occur. On the other hand, when the ⁷Be content was measured during single rain events, a high content of this radionuclide was found to be associated with very low rainfall intensity (≈3 mm h⁻¹), this suggests that rain intensity could affect the ⁷Be content. Using all data, a good linear relationship between ⁷Be deposition and rain magnitude was obtained (r²=0.82, p<0.0001). Because of this, the slope of this linear regression equation may be applied as a tool for tracing environmental processes that affect the surface of the earth. We can do this by directly estimating erosion/sedimentation processes using ⁷Be or by estimating the input of ¹⁰Be in the environment with the aim to evaluate land degradation phenomena.
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Affiliation(s)
- J Juri Ayub
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis/CCT-San Luis-CONICET, San Luis, Argentina.
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Kreiner A, Castell W, Di Paolo H, Baldo M, Bergueiro J, Burlon A, Cartelli D, Thatar Vento V, Kesque J, Erhardt J, Ilardo J, Valda A, Debray M, Somacal H, Suarez Sandin J, Igarzabal M, Huck H, Estrada L, Repetto M, Obligado M, Padulo J, Minsky D, Herrera M, Gonzalez S, Capoulat M. Development of a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy. Appl Radiat Isot 2011; 69:1672-5. [DOI: 10.1016/j.apradiso.2011.01.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 01/28/2011] [Indexed: 11/16/2022]
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Bergueiro J, Igarzabal M, Suarez Sandin J, Somacal H, Thatar Vento V, Huck H, Valda A, Repetto M, Kreiner A. Development of high intensity ion sources for a Tandem-Electrostatic-Quadrupole facility for Accelerator-Based Boron Neutron Capture Therapy. Appl Radiat Isot 2011; 69:1676-9. [DOI: 10.1016/j.apradiso.2011.02.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/10/2011] [Accepted: 02/10/2011] [Indexed: 10/18/2022]
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Huck H. Cyclische Voltammetrie an dünnen Elektrolyt- und Chemisorptionsschichten beim Vorliegen eines reversiblen Semichinon- und Dimerenbildungsgleichgewichts. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19810850310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Juri Ayub J, Di Gregorio DE, Velasco H, Huck H, Rizzotto M, Lohaiza F. Short-term seasonal variability in 7Be wet deposition in a semiarid ecosystem of central Argentina. J Environ Radioact 2009; 100:977-981. [PMID: 19716212 DOI: 10.1016/j.jenvrad.2009.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 07/08/2009] [Accepted: 08/04/2009] [Indexed: 05/28/2023]
Abstract
The (7)Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the (7)Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. (7)Be activity concentration in rainwater ranged from 0.7+/-0.3 Bq l(-1) to 3.2+/-0.7 Bq l(-1), with a mean value of 1.7 Bq l(-1) (sd=0.53 Bq l(-1)). No relationship was found between (7)Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. (7)Be ground deposition was found to be well correlated with rainfall amount (R=0.92). For the precipitation events considered, the (7)Be depositional fluxes ranged from 1.1 to 120 Bq m(-2), with a mean value of 32.7 Bq m(-2) (sd=29.9 Bq m(-2)). The annual depositional flux was estimated at 1140+/-120 Bq m(-2)y(-1). Assuming the same monthly deposition pattern and that the (7)Be content in soil decreases only through radioactive decay, the seasonal variation of (7)Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of (7)Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes.
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Affiliation(s)
- J Juri Ayub
- Grupo de Estudios Ambientales, Instituto de Matemática Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejercito de los Andes 950, D5700HHW San Luis, Argentina
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Kreiner AJ, Thatar Vento V, Levinas P, Bergueiro J, Di Paolo H, Burlon AA, Kesque JM, Valda AA, Debray ME, Somacal HR, Minsky DM, Estrada L, Hazarabedian A, Johann F, Suarez Sandin JC, Castell W, Davidson J, Davidson M, Giboudot Y, Repetto M, Obligado M, Nery JP, Huck H, Igarzabal M, Fernandez Salares A. Development of a tandem-electrostatic-quadrupole accelerator facility for BNCT. Appl Radiat Isot 2009; 67:S266-9. [PMID: 19376714 DOI: 10.1016/j.apradiso.2009.03.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In this work we describe the present status of an ongoing project to develop a tandem-electrostatic-quadrupole (TESQ) accelerator facility for accelerator-based (AB) BNCT at the Atomic Energy Commission of Argentina in Buenos Aires. The project final goal is a machine capable of delivering 30 mA of 2.4 MeV protons to be used in conjunction with a neutron production target based on the (7)Li(p,n)(7)Be reaction slightly beyond its resonance at 2.25 MeV. These are the specifications needed to produce sufficiently intense and clean epithermal neutron beams, based on the (7)Li(p,n)(7)Be reaction, to perform BNCT treatment for deep-seated tumors in less than an hour. An electrostatic machine is the technologically simplest and cheapest solution for optimized AB-BNCT. The machine being designed and constructed is a folded TESQ with a high-voltage terminal at 1.2 MV intended to work in air. Such a machine is conceptually shown to be capable of transporting and accelerating a 30 mA proton beam to 2.4 MeV. The general geometric layout, its associated electrostatic fields, and the acceleration tube are simulated using a 3D finite element procedure. The design and construction of the ESQ modules is discussed and their electrostatic fields are investigated. Beam transport calculations through the accelerator are briefly mentioned. Likewise, work related to neutron production targets, strippers, beam shaping assembly and patient treatment room is briefly described.
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Affiliation(s)
- A J Kreiner
- Departamento de Física, Comisión Nacional de Energía Atómica, Av. Gral Paz 1499 (1650), San Martín, Buenos Aires, Argentina.
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Gargarello R, Cavalitto S, Di Gregorio D, Niello JF, Huck H, Pardo A, Somacal H, Curutchet G. Characterisation of uranium(VI) sorption by two environmental fungal species using gamma spectrometry. Environ Technol 2008; 29:1341-1348. [PMID: 19149355 DOI: 10.1080/09593330802327069] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Uranium(VI) sorption by two highly uranium-resistant air-borne fungi in a low-pH medium was measured by means of gamma spectrometry. Growth kinetics and stoichiometry of the two fungal species were also studied. Results show acceptable growth rates in synthetic medium with glucose and ammonia as carbon and nitrogen sources, respectively. Typical oxidative metabolism of carbohydrates was found. In vivo uptake of the radionuclide was negligible, but biosorption dry biomass presented a remarkable performance. The fungal strains showed potential for use in bioremediation.
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Affiliation(s)
- R Gargarello
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Provincia de Buenos Aires, Argentina
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Di Gregorio DE, Fernández Niello JO, Huck H, Somacal H, Curutchet G. 210Pb dating of sediments in a heavily contaminated drainage channel to the La Plata estuary in Buenos Aires, Argentina. Appl Radiat Isot 2007; 65:126-30. [PMID: 16934477 DOI: 10.1016/j.apradiso.2006.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 06/29/2006] [Accepted: 06/29/2006] [Indexed: 10/24/2022]
Abstract
Concentrations of (210)Pb and (137)Cs in sediment samples collected from two cores at a drainage channel to the La Plata river estuary in Buenos Aires, Argentina, were measured using ultralow-background detection systems. The (210)Pb data were used to determine the rate of sediment accumulation of the sites. These results were correlated with some heavy metal (chromium and lead) concentrations of the samples in an attempt to characterize the historical input of contaminants due to the industrial development, which has taken place in this area over the last century. The (137)Cs measurements demonstrate that cesium dating is not adequate in regions of the southern hemisphere.
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Affiliation(s)
- D E Di Gregorio
- Departamento de Física, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, 1650 San Martín, Provincia de Buenos Aires, Argentina.
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Di Gregorio DE, Huck H, Aristegui R, De Lazzari G, Jech A. 137Cs contamination in tea and yerba mate in South America. J Environ Radioact 2004; 76:273-281. [PMID: 15261416 DOI: 10.1016/j.jenvrad.2003.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2003] [Revised: 11/20/2003] [Accepted: 11/25/2003] [Indexed: 05/24/2023]
Abstract
Gamma-ray spectra from more than 50 samples of food products available in stores of Buenos Aires city were measured using a germanium detector. Activity concentrations of 137Cs up to 10 Bq/kg were found in tea and yerba mate manufactured in Apóstoles, Argentina. Further measurements of tea leaves, yerba mate leaves and soils, all coming from a cultivated area in that region, also show the presence of 137Cs contamination. The results suggest that the area was fertilized with a product that originated in a region affected by the fallout from the Chernobyl nuclear plant accident.
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Affiliation(s)
- D E Di Gregorio
- Departamento de Ciencias Básicas, Universidad Nacional de Luján, Rutas 5 y 7, Luján, Provincia de Buenos Aires, Argentina.
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Abstract
PURPOSE There are many different excimer laser devices available for photoablative refractive surgery. Smoothness of ablation may vary with different excimer lasers systems. METHODS Ablations were performed on polymethylmethacrylate (PMMA) plates of 8 x 4 x 0.5 cm, with four different excimer lasers: VISX-Star, Coherent Schwind Keratom I/II, Chiron Technolas Keracor 117C (Plano Scan), and the Nidek EC-5000, to determine and compare the homogeneity and smoothness of the surface. Ten -3.00 D samples, ten -6.00 D samples, and ten -9.00 D samples were ablated with each laser. The PMMA discs were examined with optical microscopy, documented by photographs, and each sample was measured quantitatively using a Hommel-Werkel rugosimeter. We used the same PMMA material throughout. RESULTS Statistically significant differences in smoothness were found between the Chiron Technolas 117C and the VISX-Star, Nidek and VISX-Star, and Coherent Schwind and VISX-Star in the homogeneities achieved by ablating -3.00 D. Ablations of -6.00 D resulted in homogeneities that were statistically significantly different: Chiron Technolas 117C with the other three devices, the Nidek EC-5000 with the VISX-Star, and the Coherent-Schwind with the VISX-Star. In the ablations for -9.00 D, statistically significant differences in homogeneity were found between the Chiron Technolas 117C and Nidek, between the Chiron and VISX-Star, between the Coherent Schwind and VISX-Star, and between the Nidek and VISX-Star. The laser with the scanning spot system was smoother. CONCLUSION Scanning spot technology produced smooth ablations even up to -9.00 D.
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Affiliation(s)
- C Argento
- Cornea Department, Hospital de Clínicas Jose de San Martin, Buenos Aires, Argentina
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DiGregorio DE, Gil S, Huck H, Batista ER, Ferrero AM, Gattone AO. No evidence of the 17-keV neutrino in the decay of 71Ge. Phys Rev C Nucl Phys 1993; 47:2916-2923. [PMID: 9968767 DOI: 10.1103/physrevc.47.2916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Huck H. Temperature dependence of the sensitivity of platinized gas-diffusion electrodes towards ethanol and acetone. J Electroanal Chem (Lausanne) 1992. [DOI: 10.1016/0022-0728(92)80547-h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Huck H, Jech A, Martí G, Pérez ML, Rossi JJ, Sofía HM. 123Cd level scheme. Phys Rev C Nucl Phys 1989; 40:1384-1389. [PMID: 9966112 DOI: 10.1103/physrevc.40.1384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abriola D, Achterberg E, Davidson M, Debray M, Etchegoyen M, Fazzini N, Niello J, Ferrero A, Filevich A, Galia M, Garavaglia R, Bermúdez G, Gettar R, Gil S, Grahmann H, Huck H, Jech A, Kreiner A, Macchiavelli A, Magallanes J, Maqueda E, Martí G, Pacheco A, Pérez M, Pomar C, Ramírez M, Scasserra M. Examination of nuclear measurement conditions in cold fusion experiments. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0022-0728(89)80206-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Huck H, Jech A, Martí G, Pérez ML, Rossi JJ, Sofí HM. Isomers in the 123Cd and 125Cd decays and level schemes in 123In and 125In. Phys Rev C Nucl Phys 1989; 39:997-1011. [PMID: 9955291 DOI: 10.1103/physrevc.39.997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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21
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Huck H. On the characterization of packed-bed enzyme reactors by conversion experiments. J Electroanal Chem (Lausanne) 1989. [DOI: 10.1016/0022-0728(89)87198-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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23
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Huck H, Schelter-Graf A, Schmidt HL. Measurement and calculation of the calibration graphs for flow injection analysis using enzyme reactors with immobilized dehydrogenases and an amperometric NADH detector. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0302-4598(84)85127-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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25
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Huck H. Dünnschichtchromatographische Bestimmung von Acylaminoäthyl-arylsulfonylharnstoffen im Serum nach Hydrolyse und Dansylierung. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/s0378-4347(00)81218-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Huck H. [Thin layer chromatographic determination of serum acylaminoethylarylsulfonylurea following hydrolysis and dansylation]. J Chromatogr 1978; 146:533-7. [PMID: 721933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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27
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28
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29
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Huck H. [Fluorimetric determination of testosterone on Al2O3 by thin-layer chromatographic separation of the trimethylsilyl ether derivatives (author's transl)]. J Chromatogr A 1975; 110:125-31. [PMID: 1133140 DOI: 10.1016/s0021-9673(00)91217-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Small quantities (parts per 10-9) of testosterone were determined in the presence of large amounts of other steroids in urine samples obtained during pregnancy by subjecting their trimethylsilyl derivatives to spectrofluorimetry on alumina after purification by thin-layer chromatography on silica gel. The activity of the alumina and the fluorescence reactions are discussed.
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30
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Huck H. Der potentialverlauf galvanischer sensoren bei pulsförmiger probenaufgabe. J Electroanal Chem (Lausanne) 1974. [DOI: 10.1016/0368-1874(74)80034-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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32
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33
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Huck H, Dworzak E. [Quantitative analysis of catecholamine and serotonin metabolites on thin-layer plates. II. Reflectance measurements after a specific photochemical reaction]. J Chromatogr A 1972; 74:303-10. [PMID: 4345687 DOI: 10.1016/s0021-9673(01)86159-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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Huck H, Egg D. [Gas-chromatography determination of urinary metabolites in substitution therapy using 1 -methyl-5 -androstane-17 -OL-3-ON (mesterolone)]. Wien Klin Wochenschr 1972; 84:114-7. [PMID: 5059857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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35
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36
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Huck H. [Quantitative evaluation of gas chromatographically separated steroids from the products of breakthrough time and peak height]. J Chromatogr A 1971; 62:47-52. [PMID: 5130017 DOI: 10.1016/s0021-9673(01)96808-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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37
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Dworzak E, Huck H. Quantitative Analyse von Katecholamin- und Serotoninmetaboliten mittels Fluoreszenzlöschung auf der Dünnschichtplatte. J Chromatogr A 1971. [DOI: 10.1016/s0021-9673(00)92399-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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38
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Diemair W, Huck H. Das Verhalten der Stärke und der Chlorogensäure bei der technologischen Bearbeitung und Lagerung von Kartoffeln. ACTA ACUST UNITED AC 1962. [DOI: 10.1002/food.19620060712] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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