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Fast Neutron Scintillator Screens for Neutron Imaging Using a Layered Polymer-Phosphor Architecture. QUANTUM BEAM SCIENCE 2022. [DOI: 10.3390/qubs6020014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fast neutrons enable a nondestructive examination of dense, large, and highly attenuating samples due to their lower interaction probability compared to thermal neutrons. However, this also creates a challenge in fast neutron imaging, as the thicker sensors necessary to detect fast neutrons degrade an image’s spatial resolution due to scattering within the sensor and the indeterminate depth of interaction in the sensor. This work explores the advantages of a fast neutron imaging screen with a layered polymer-phosphor screen approach as opposed to a mixed polymer-phosphor screen typically used in fast neutron imaging. Proton recoil is the primary conversion mechanism for fast neutron imaging. Simulations showed that the recoil proton range of typical fast neutrons is approximately 200 µm, however, tests at Idaho National Laboratory revealed that the light output of these screens increased at much greater polymer thicknesses. The NECTAR fast neutron beamline at FRM II was used to test the imaging performance of layered fast neutron imaging screens. Distinguishing between the fast-neutron and γ-ray signals is a major challenge in fast neutron imaging because all fast neutron sources also produce γ-rays. A relative comparison between a control plate and the fast neutron screen was made to distinguish between a γ-ray and fast neutron signals. MCNP modeling quantified the γ-ray and fast neutron contributions to the images measured at NECTAR, which were approximately a 75% γ-ray image.
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Morad V, McCall KM, Sakhatskyi K, Lehmann E, Walfort B, Losko AS, Trtik P, Strobl M, Yakunin S, Kovalenko MV. Luminescent Lead Halide Ionic Liquids for High-Spatial-Resolution Fast Neutron Imaging. ACS PHOTONICS 2021; 8:3357-3364. [PMID: 34820475 PMCID: PMC8603383 DOI: 10.1021/acsphotonics.1c01348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Indexed: 05/12/2023]
Abstract
The fast neutron imaging technique with recoil proton detection harbors significant potential for imaging of thick, large-scale objects containing high-Z elements. However, the challenge to find efficient fast neutron scintillators with high spatial resolution is ongoing. The list of requirements for such scintillators is long and demanding: a proton-rich, scattering-free material combining high light yield with the absence of light reabsorption. To meet these challenges, we look for a suitable material among a rising class of 0D organic-inorganic Pb(II) halide hybrids. The use of large organic cations, e.g., trihexyltetradecylphosphonium, results in room-temperature ionic liquids that combine highly Stokes-shifted (up to 1.7 eV), reabsorption-free, and efficient emission (photoluminescence quantum yield up to 60%) from molecularly small and dense (PbX2 molar fraction up to 0.33) emitting centers. We investigate the optical properties of the resulting ionic liquids and showcase their utility as fast neutron imaging scintillators. Concomitantly with good light yield, such fast-neutron scintillators exhibit both higher spatial resolution and lower γ-ray sensitivity compared with commercial ZnS:Cu-based screens.
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Affiliation(s)
- Viktoriia Morad
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa −
Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Kyle M. McCall
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa −
Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Kostiantyn Sakhatskyi
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa −
Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | | | | | - Adrian S. Losko
- Forschungs-Neutronenquelle
Heinz Maier-Leibnitz, 85748 Garching, Germany
| | - Pavel Trtik
- Paul
Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Markus Strobl
- Paul
Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Sergii Yakunin
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa −
Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Maksym V. Kovalenko
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa −
Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
- E-mail:
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McCall KM, Sakhatskyi K, Lehmann E, Walfort B, Losko AS, Montanarella F, Bodnarchuk MI, Krieg F, Kelestemur Y, Mannes D, Shynkarenko Y, Yakunin S, Kovalenko MV. Fast Neutron Imaging with Semiconductor Nanocrystal Scintillators. ACS NANO 2020; 14:14686-14697. [PMID: 32897688 DOI: 10.1021/acsnano.0c06381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Fast neutrons offer high penetration capabilities for both light and dense materials due to their comparatively low interaction cross sections, making them ideal for the imaging of large-scale objects such as large fossils or as-built plane turbines, for which X-rays or thermal neutrons do not provide sufficient penetration. However, inefficient fast neutron detection limits widespread application of this technique. Traditional phosphors such as ZnS:Cu embedded in plastics are utilized as scintillators in recoil proton detectors for fast neutron imaging. However, these scintillation plates exhibit significant light scattering due to the plastic-phosphor interface along with long-lived afterglow (on the order of minutes), and therefore alternative solutions are needed to increase the availability of this technique. Here, we utilize colloidal nanocrystals (NCs) in hydrogen-dense solvents for fast neutron imaging through the detection of recoil protons generated by neutron scattering, demonstrating the efficacy of nanomaterials as scintillators in this detection scheme. The light yield, spatial resolution, and neutron-vs-gamma sensitivity of several chalcogenide (CdSe and CuInS2)-based and perovskite halide-based NCs are determined, with only a short-lived afterglow (below the order of seconds) observed for all of these NCs. FAPbBr3 NCs exhibit the brightest total light output at 19.3% of the commercial ZnS:Cu(PP) standard, while CsPbBrCl2:Mn NCs offer the best spatial resolution at ∼2.6 mm. Colloidal NCs showed significantly lower gamma sensitivity than ZnS:Cu; for example, 79% of the FAPbBr3 light yield results from neutron-induced radioluminescence and hence the neutron-specific light yield of FAPbBr3 is 30.4% of that of ZnS:Cu(PP). Concentration and thickness-dependent measurements highlight the importance of increasing concentrations and reducing self-absorption, yielding design principles to optimize and foster an era of NC-based scintillators for fast neutron imaging.
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Affiliation(s)
- Kyle M McCall
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Kostiantyn Sakhatskyi
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | | | | | - Adrian S Losko
- Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Garching, 85748, Germany
| | - Federico Montanarella
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Maryna I Bodnarchuk
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Franziska Krieg
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Yusuf Kelestemur
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
- Department of Metallurgical and Materials Engineering, Atilim University, Ankara, 06830, Turkey
| | - David Mannes
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | - Yevhen Shynkarenko
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Sergii Yakunin
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
| | - Maksym V Kovalenko
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, Zürich, CH-8093, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, CH-8600, Switzerland
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Recognition of Pharmacological Bi-Heterocyclic Compounds by Using Terahertz Time Domain Spectroscopy and Chemometrics. SENSORS 2019; 19:s19153349. [PMID: 31366175 PMCID: PMC6696483 DOI: 10.3390/s19153349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/20/2019] [Accepted: 07/27/2019] [Indexed: 12/22/2022]
Abstract
In this study, we presented the concept and implementation of a fully functional system for the recognition of bi-heterocyclic compounds. We have conducted research into the application of machine learning methods to correctly recognize compounds based on THz spectra, and we have described the process of selecting optimal parameters for the kernel support vector machine (KSVM) with an additional `unknown' class. The chemical compounds used in the study contain a target molecule, used in pharmacy to combat inflammatory states formed in living organisms. Ready-made medical products with similar properties are commonly referred to as non-steroidal anti-inflammatory drugs (NSAIDs) once authorised on the pharmaceutical market. It was crucial to clearly determine whether the tested sample is a chemical compound known to researchers or is a completely new structure which should be additionally tested using other spectrometric methods. Our approach allows us to achieve 100% accuracy of the classification of the tested chemical compounds in the time of several milliseconds counted for 30 samples of the test set. It fits perfectly into the concept of rapid recognition of bi-heterocyclic compounds without the need to analyse the percentage composition of compound components, assuming that the sample is classified in a known group. The method allows us to minimize testing costs and significant reduction of the time of analysis.
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Košťál M, Matěj Z, Mravec F, Cvachovec F, Schulc M, Juříček V, Rypar V, Šoltés J, Losa E, Viererbl L. Testing of Scintillation Detectors in Quasi-Monoenergetic Neutron Spectra in a Silicon Filtered Neutron Beam at the LVR-15 Research Reactor. JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2019. [DOI: 10.1115/1.4043197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With increasing needs of neutron detection in energy and homeland security sectors, there is an aim in the development of new suitable detection materials with possible n/g separation and also satisfactory resolution. This issue is connected with a well-defined neutron field. The neutron standards 252Cf(spontaneous fission) and 235U(nth fission) have smooth spectra; thus, the tests in these fields can be used for testing of neutron gamma pulse shape discrimination (PSD), but cannot reveal possible problems in the deconvolution. New neutron field which is formed from fission spectrum filtered by 1 m thick silicon block was developed in Research Center Rez. Due to the course of the silicon cross section, the well-distinguished neutron peaks occur in filtered neutron spectrum. In this field, various scintillation materials, HIDEX Aqualight, and EJ299-33A were tested.
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Affiliation(s)
- Michal Košťál
- Research Center Rez, Ltd., Husinec-Rez 250 68, Czech Republic e-mail:
| | - Zdeněk Matěj
- Faculty of Informatics, Masaryk University, Botanická 15, Brno 612 00, Czech Republic
| | - Filip Mravec
- Faculty of Informatics, Masaryk University, Botanická 15, Brno 612 00, Czech Republic
| | - František Cvachovec
- Department of Mathematics and Physics, University of Defence, Kounicova 65, Brno 612 00, Czech Republic
| | - Martin Schulc
- Research Center Rez, Ltd., Husinec-Rez 250 68, Czech Republic
| | | | - Vojtěch Rypar
- Research Center Rez, Ltd., Husinec-Rez 250 68, Czech Republic
| | - Jaroslav Šoltés
- Research Center Rez, Ltd., Husinec-Rez 250 68, Czech Republic
| | - Evžen Losa
- Research Center Rez, Ltd., Husinec-Rez 250 68, Czech Republic
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Effect of the LEGe detector collimators on K-series peaks and Compton scattering in XRF analysis using gamma rays. Heliyon 2018; 4:e00724. [PMID: 30105311 PMCID: PMC6086212 DOI: 10.1016/j.heliyon.2018.e00724] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/09/2018] [Accepted: 08/01/2018] [Indexed: 11/20/2022] Open
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9
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Pour Yazdanpanah A, Hartman J, Regentova E, Barzilov A. Sparse-view neutron-photon computed tomography: Object reconstruction and material discrimination. Appl Radiat Isot 2017; 132:122-128. [PMID: 29220725 DOI: 10.1016/j.apradiso.2017.11.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 11/26/2017] [Accepted: 11/27/2017] [Indexed: 10/18/2022]
Abstract
Taking into account the advantages of both neutron- and photon-based systems, we propose combined neutron-photon computed tomography (CT) under a sparse-view setting and demonstrate its performance for 3D object visualization and material discrimination. We use a high-performance regularization method for CT reconstruction by combining regularization based on total variation (TV) and curvelet transform in cone beam geometry. It is coupled with proposed 2D material signatures which is pairs of photon to neutron transmission ratios and neutron transmission values per object space voxels. Classification of materials is performed by association of a voxel signature with library signatures; and per object - by majority of voxels in the object. Representation of object-material pairs, for the model in our experiment, a complex scene with group of high-Z and low-Z materials, attains the reconstruction accuracy of 92.1% and the overall high-Z discrimination accuracy of object representation is 85%, and by about 7.5% higher discrimination accuracy than that with 1D signatures which are ratios of photon to neutron transmissions. With a relative noise level of 10%, the method yields the reconstruction accuracies of 87.2%. The analyses are performed in cone beam configuration, with Monte Carlo modeling of neutron-photon transport for the model of object geometry and material contents.
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Lehnert AL, Kearfott KJ. Simplified Simulation of Fast Neutron Scattering for an Explosives Detection Application. NUCL SCI ENG 2017. [DOI: 10.13182/nse10-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. L. Lehnert
- University of Michigan, Department of Nuclear Engineering and Radiological Sciences 2355 Bonisteel Boulevard, Ann Arbor, Michigan 48109-2104
| | - K. J. Kearfott
- University of Michigan, Department of Nuclear Engineering and Radiological Sciences 2355 Bonisteel Boulevard, Ann Arbor, Michigan 48109-2104
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A 14 MeV neutron irradiation facility with an automated fast cyclic pneumatic. J Radioanal Nucl Chem 2016. [DOI: 10.1007/s10967-016-4725-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Heider S, Dunn W. A simulation study of fast neutron interrogation for standoff detection of improvised explosive devices. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Whetstone ZD, Kearfott KJ. A review of conventional explosives detection using active neutron interrogation. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3260-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Study of Doppler broadening of gamma-ray spectra in 14-MeV neutron activation analysis. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3189-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Naqvi AA, Al-Matouq FA, Khiari FZ, Isab AA, Raashid M, Khateeb-ur-Rehman. Hydrogen, carbon and oxygen determination in proxy material samples using a LaBr3:Ce detector. Appl Radiat Isot 2013; 78:145-50. [PMID: 23673256 DOI: 10.1016/j.apradiso.2013.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 10/27/2022]
Abstract
Hydrogen, carbon and oxygen concentrations were measured in caffeine, urea, ammonium acetate and melamine bulk samples via 14 MeV neutron inelastic scattering using a LaBr3:Ce detector. The samples tested herein represent drugs, explosives and benign materials, respectively. Despite its intrinsic activity, the LaBr3:Ce detector performed well in detecting the hydrogen, carbon and oxygen elements. Because 5.1 MeV nitrogen gamma rays interfere with silicon and calcium prompt gamma rays from the room background, the nitrogen peak was not detected in the samples. An excellent agreement was observed between the experimental and theoretical yields of 2.22, 4.43 and 6.13 MeV gamma rays from the analyzed samples as a function of H, C and O concentrations, respectively. Within statistical errors, the minimum detectable concentration (MDC) of hydrogen, carbon and oxygen elements in the tested materials were consistent with previously reported MDC values for these elements measured in hydrocarbon samples.
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Affiliation(s)
- A A Naqvi
- Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia.
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Perot B, El Kanawati W, Carasco C, Eleon C, Valkovic V, Sudac D, Obhodas J, Sannie G. Quantitative comparison between experimental and simulated gamma-ray spectra induced by 14 MeV tagged neutrons. Appl Radiat Isot 2011; 70:1186-92. [PMID: 21782459 DOI: 10.1016/j.apradiso.2011.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 07/06/2011] [Accepted: 07/07/2011] [Indexed: 11/27/2022]
Abstract
Fast neutron interrogation with the associated particle technique can be used to identify explosives in cargo containers (EURITRACK FP6 project) and unexploded ordnance on the seabed (UNCOSS FP7 project), by detecting gamma radiations induced by 14 MeV neutrons produced in the 2H(3H,α)n reaction. The origin of the gamma rays can be determined in 3D by the detection of the alpha particle, which provides the direction of the opposite neutron and its time-of-flight. Gamma spectroscopy provides the relative counts of carbon, nitrogen, and oxygen, which are converted to chemical fractions to differentiate explosives from other organic substances. To this aim, Monte Carlo calculations are used to take into account neutron moderation and gamma attenuation in cargo materials or seawater. This paper presents an experimental verification that C, N, and O counts are correctly reproduced by numerical simulation. A quantitative comparison is also reported for silicon, iron, lead, and aluminium.
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Affiliation(s)
- B Perot
- CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance, France.
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