Annual Report 2009/2010 - JUWEL - Forschungszentrum Jülich

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Characterization of the synthesized pyrochlores by thermal analysis To get a deeper understanding about the process of crystallization of the neodymium zirconate systems the products of the internal gelation and the coprecipitation were analysed by thermogravimetry (TG) and differential scanning calorimetry (DSC). The samples were heated up from room temperature to 1300 °C with a heating rate of 10 K/min. Fig. 66 shows the TG/DSC thermogram of a neodymium zirconate synthesized by coprecipitation. Between the temperatures of 109 °C – 344 °C the DSC-curve exhibits four endothermic peaks. These peaks can be attributed to the desorption of adsorbed water and a possible decomposition of impurities. To investigate the process of crystallization in detail, x-ray measurements were carried out in addition to the TG/DSC-measurements. The x-ray measurements were taken from samples that were heated to temperatures right before and after the four exothermic peaks at 407 °C, 514 °C, 684 °C and 811 °C and subsequently quenched to room temperature. Using these x-ray measurements we were able to attribute the peaks to the solid solution formation. 100 407°C 514°C TG DSC 0,3 Exo 90 0,1 684°C 811°C TG/% 80 70 109°C 154°C 258°C 344°C -0,1 -0,3 DSC/(mW/mg) 60 0 150 300 450 600 750 900 1050 1200 T/°C -0,5 Fig. 66: TG/DSC-curves of a neodymium zirconate by coprecipitation with gaseous ammonia as precipitation agent. Fig. 67 shows the TG/DSC thermogram of a neodymium zirconate from the internal-gelation process. The thermogram exhibits only one endothermic and a single exothermic effect. The endothermic peak at 120 °C is caused by the desorption of adsorbed water. The exothermic peak at 785 °C indicates the solid solution formation of Nd 2 Zr 2 O 7 . Comparing the synthesis routes described above the process of crystallization for the sol-gel route is straightforward while the crystallization process of the coprecipitation product occurs in several steps. Nevertheless the coprecipitation seems more favourable than the internal gelation due to the difficulties involved with the sol-formulation. 93
100 TG 785°C Exo DSC 0,2 0,0 90 -0,2 TG/% 80 -0,4 DSC/(mW/mg) -0,6 70 -0,8 120°C 60 0 125 250 375 500 625 750 875 1000 1125 1250 T/°C -1,0 Fig. 67: TG/DSC thermogram of a neodymium zirconate by internal gelation. Conclusion Among the three wet chemical synthesis routes conducted in this work coprecipitation and the sol-gel route were successful for the preparation of pyrochlore-type zirconates. The characterization of the products with XRD and SEM exhibits single phase Nd 2 Zr 2 O 7 pyrochlore. The scanning electron microscopy image shows that coprecipitation as well as internal gelation lead to a homogeneous product which was proofed by backscattered electron images. In summary, the sol-gel synthesis is a straightforward synthesis-route for the preparation of Nd 2 Zr 2 O 7 . However, any variation in the Nd/Zr-system complicates the internal gelation process because the sol-formulation needs to be adjusted every time. Despite its multi stage formation process coprecipitation is easy to control and therefore has great potential for the preparation of zirconia-based pyrochlores even with changes in the Nd/Zr-system. Acknowledgements This work is supported by the Ministerium für Innovation, Wissenschaft, Forschung und Technologie des Landes (MIWFT) Nordrhein-Westfalen; AZ: 323-005-0911-0129. References [1] G. R. Lumpkin, Elements 2 (2006) 365-372. [2] R. C. Ewing, C. R. Geoscience 343 (2011) 219-229. [3] B. C. Chakoumakos, R. C. Ewing, Mater. Res. Soc. Symp. Proc. 44 (1985) 641-646. [4] R. C. Ewing, W. J. Weber, J. Lian, J. Appl. Phys. 95 (2004) 5949-5971. [5] Y. P. Tong, J. W. Zhu, L. D. Lu, X. Wang, X. J. Yang, J. Alloy. Comp. 465 (2008) 280-284. [6] N. Hingant, N. Clavier, N. Dacheux, N. Barre, S. Hubert, S. Obbade, F. Taborda, F. Abraham, J. Nucl. Mater. 385 (2009) 400-406. [7] D. Chen, R. Xu, Mater. Res. Bull. 33 (1998) 409-417. [8] H. F. Chen, Y. F. Gao, Y. Liu, H. J. Luo, J. Alloy. Comp. 480 (2009) 843-848. [9] J. L. Collins, M. H. Lloyd, R. L. Fellows, Radiochim. Acta 42 (1987) 121-134. [10] J. L. Collins, K. K. Anderson, Report Number ORNL/CP-96463, 1998. 94
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Mitglied Mitglied der der Helmholtz
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Forschungszentrum Jülich GmbH Inst
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TABLE OF CONTENTS 1 Preface .......
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6.2.2 Doctoral Thesis .............
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state of NRW. The collaborative pro
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2 Institute’s Profile Due to the
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2.2. Organization chart Reactor Saf
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3 Key Research Topics 3.1. Long Ter
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actinide co-conversion into polyact
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Fig. 7: Non-destructive analytical
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Fig. 9: Thermal treatment of an AVR
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3.8. Product Quality Control of Rad
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3.8.2 Product Quality Control of Lo
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The advantage of working at low vac
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NdPO 4 powder sample, directly rece
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4.5. Non-destructive assay testing
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5 Scientific and Technical Reports
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Results and Discussion The irradiat
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work will focus on the identificati
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Different solvents (iso-propanol an
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e & j) Aggregates of aluminium oxid
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Experimental details The corrosion
Page 47 and 48: Intensity [CPS] 500 400 300 200 100
Page 49 and 50: Fig. 24: Left: High resolution TEM
Page 51 and 52: a) MD model [10] b) Derived Lesukit
Page 53 and 54: 5.4. Minor actinide(III) recovery f
Page 55 and 56: Extensive extraction studies were p
Page 57 and 58: of the extraction properties of the
Page 59 and 60: Cm(III) together with the lanthanid
Page 61 and 62: using a mixture of CyMe4BTBP and TO
Page 63 and 64: A more challenging route studied wi
Page 65 and 66: These preliminary results show that
Page 67 and 68: The 1-cycle SANEX process is intend
Page 69 and 70: Continuous counter-current tests us
Page 71 and 72: Conclusion In this work, it was sho
Page 73 and 74: shaken by a vortex mixer for 15 min
Page 75 and 76: 100 100 Distribution ratio 10 1 0.1
Page 77 and 78: Tab. 15: The distribution ratios of
Page 79 and 80: 5.7. Synthesis and thermal treatmen
Page 81 and 82: Acid-Deficient Uranyl-Nitrate via d
Page 83 and 84: Optical investigation showed a noti
Page 85 and 86: TG /% 100 98 96 94 92 90 88 86 84 8
Page 87 and 88: Radiolysis in the aqueous solutions
Page 89 and 90: is about 4% while the one of the rh
Page 91 and 92: Fig. 59: Compressibility curve for
Page 93 and 94: Conclusion and outlook Monazite-typ
Page 95 and 96: Fig. 63: Description of the unit ce
Page 97: agents for the synthesis of neodymi
Page 101 and 102: After synthesis the product was cen
Page 103 and 104: process of monazite and additional
Page 105 and 106: Tab. 18: Lattice parameters determi
Page 107 and 108: Conclusions For Sm 1-x Ce x PO 4 mo
Page 109 and 110: 5.11. Raman Spectra of Synthetic Ra
Page 111 and 112: The numerical values of all measure
Page 113 and 114: knowledge, these special relationsh
Page 115 and 116: Fig. 80: Raman spectra of LaPO 4 ir
Page 117 and 118: 5.12. MC simulation of thermal neut
Page 119 and 120: content was replaced by hydrogen. C
Page 121 and 122: constant for hydrogen concentration
Page 123 and 124: with a 0 1 -183.88 ± 8.55 and a 2
Page 125 and 126: 5.13. An Improved Method for the no
Page 127 and 128: 2 2 2 d0 R ds d0 dw la( )
Page 129 and 130: The relative uncertainty for the ac
Page 131 and 132: In the drum, 4 ‘hot spots’ for
Page 133 and 134: activity of Cs-137 is much more und
Page 135 and 136: gamma-ray detector approximated by
Page 137 and 138: shown in Fig. 96. In both cases the
Page 139 and 140: econstruction than the old calculat
Page 141 and 142: Neutron capture cross sections and
Page 143 and 144: Outlook The evaluated data will be
Page 145 and 146: from carbon-based HTR fuel elements
Page 147 and 148: Fig. 102: 3D volume reconstructions
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dislocate the 14 C atom from its pr
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It can be seen that nearly all trit
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Acknowledgement The authors like to
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development by investigations of ga
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Fig. 109: The left picture shows th
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[2] A European Roadmap for Developi
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from airborne SWIR Full Spectrum Im
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Fig. 113: Visualization of the vege
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number of training samples up to 19
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Acknowledgements The work presented
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three approaches has severe drawbac
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neighbours from the list of merge c
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it gives a difference in segmentati
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[6] I. Niemeyer, F. Bachmann, A. Jo
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Monitoring 3 cooperated intensively
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facilities and other treaty related
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parameters of the SAR system, such
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The MGD products used in the study
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Fig. 134 contains the result for th
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[2] H. Maître (ed.), Processing of
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Preparatory Committee to allocate t
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unconditional security assurances f
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safeguards was also requested. Deci
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[16] United Nations Security Counci
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5.24. Development and Application o
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Hardware layer The hardware layer i
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So in most applications the scale u
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The ENDF-B/V and ENDF-B/VI librarie
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5.26. Product control of waste prod
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Polysiloxane which has been investi
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acceptance requirements [3]. In the
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Fig. 145: List of description and d
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6.1. Courses taught at universities
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Umwelt / Energy & Environment 2010;
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6.5. Institute Seminar The IEK-6 or
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6.5.3 Invited talks 2009 30.04.2009
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21.09.2010 Dr. N. Evans: The Chemis
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8 Selected R&D projects 8.1. EU pro
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K. Aymanns: Nominated as deputy re
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Bukaemskiy A.A., Barrier D., Modolo
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11.2. Publications 2009 11.2.1 Jour
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Rezniczek, A.; Richter, B.; Jussofi
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Daniels, H.: Co-conversion of actin
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11.3. Publications 2010 11.3.1 Jour
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Sypula, M.; Wilden, A.; Schreinemac
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(Partitioning) - Stabilitätsunters
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Modolo, G.; Bosbach, D.; Geist, A.;
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12 How to reach us Postal Address F
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By train: Take the train from Aache
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Schriften des Forschungszentrums J
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