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Sample records for eu hcpb tbm

  1. Test Strategy for the European HCPB Test Blanket Module in ITER

    SciTech Connect

    Boccaccini, L.V.; Meyder, R.; Fischer, U.

    2005-05-15

    According to the European Blanket Programme two blanket concepts, the Helium Cooled Pebble Bed (HCPB) and a Helium Cooled Lithium Lead (HCLL) will be tested in ITER. During 2004 the test blanket modules (TBM) of both concepts were redesigned with the goal to use as much as possible similar design options and fabrication techniques for both types in order to reduce the European effort for TBM development. The result is a robust TBM box being able to withstand 8 MPa internal pressure in case of in-box LOCA; the TBM box consists of First wall (FW), caps, stiffening grid and manifolds. The box is filled with typically 18 and 24 breeding units (BU), for HCPB and HCLL respectively. A breeding unit has about 200 mm in poloidal and toroidal direction and about 400 mm in radial direction; the design is adapted to contain and cooling ceramic breeder/beryllium pebble beds for the HCPB and eutectic Lithium-Lead for the HCLL.The use of a new material, EUROFER, and the innovative design of these Helium Cooled components call for a large qualification programme before the installation in ITER; availability and safety of ITER should not be jeopardised by a failure of these components. Fabrication technologies especially in the welding processes (diffusion welding, EB, TIG, LASER) need to be tested in the manufacturing of large mock-ups; an extensive out-of-pile programme in Helium facility should be foreseen for the verification of the concept from basic helium cooling functions (uniformity of flow in parallel channels, heat transfer coefficient in FW, etc.) up to the verification of large portions of the TBM design under relevant ITER loading.In ITER the TBM will have the main objective to collect information that will contribute to the final design of DEMO blankets. A strategy has been proposed in 2001 that leads to the tests in ITER 4 different Test Blanket Modules (TBM's) type during the first 10 years of ITER operation. For the new HCPB design this strategy is confirmed with

  2. Thermo-mechanical testing of Li?ceramic for the helium cooled pebble bed (HCPB) breeding blanket

    NASA Astrophysics Data System (ADS)

    Dell'Orco, G.; Ancona, A.; DiMaio, A.; Simoncini, M.; Vella, G.

    2004-08-01

    The helium cooled pebble bed (HCPB) Test blanket module (TBM) for the DEMO Reactor foresees the utilization of lithiate ceramics as breeder in form of pebble beds. The pebbles are organized in several layers alternatively stacked among couples of cooling plates (CP). ENEA has launched an experimental programme for the out-of-pile thermo-mechanical testing of mock-ups simulating a portion of the HCPB-TBM. The programme foresees the fabrication and testing of different mock-ups, to be tested in the HE-FUS3 facility at ENEA Brasimone. The paper describes the HELICHETTA III campaign carried-out in 2003. In particular, the test section layout, the pebble filling procedure, the experimental set-up and the results of the relevant thermo-mechanical test are herewith presented.

  3. Seismic Imaging from a TBM

    NASA Astrophysics Data System (ADS)

    Swinnen, G.; Thorbecke, J. W.; Drijkoningen, G. G.

    2007-12-01

    Seismic monitoring from the head of a tunnel-boring machine (TBM) enables improved assessment of the risks associated with the tunnel-boring process. The monitoring system provides a live image of ground conditions along the trajectory followed by the TBM and detects local heterogeneities such as boulders, foundations, and other obstacles that commonly pass undetected using local geotechnical techniques. From a seismic perspective, the underground setting of tunnelling projects places limitations on imaging capability. The principal limiting factor is the size of the area upon which transducers can be installed. This limitation requires adjustments to traditional seismic imaging techniques in which a large area is assumed to be available for attaching the transducers. Recently developed short imaging operators take this limitation into account and are used in the examples described herein. The unique conditions of tunnelling yield two advantages over traditional settings in terms of imaging: rotation of the cutter wheel and the lateral progression of the TBM. Rotation of the cutter wheel, upon which the transducers are installed, provides the opportunity to illuminate obstacles from different angles in different recordings. Spatial progression of the TBM enables improvement in the illumination of obstacles and the signal-to-noise ratio by combining recordings from different lateral positions. In this paper, these specific aspects of seismic imaging during tunnelling are discussed via models that represent different cases encountered in actual tunnelling projects. These case studies demonstrate the way in which image quality along the trajectory of the TBM is improved over that in traditional settings. In this way, the risks associated with the tunnelling process can be more accurately assured.

  4. A study of structural differences between TBM patients' and non-TBM persons' CSF using UV-Vis absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Fangcheng; Wang, Xin; Xu, Huajia; Wang, Kai

    2016-01-01

    Tuberculous meningitis (TBM) is a very common infectious disease in the central nervous system. The delay of diagnosing and treating TBM will lead to high disability and mortality of TBM. Hence, it is very important to promptly diagnose TBM early. In this work, we proposed a new method for diagnosing TBM with CSF samples by using UV-Vis absorption spectroscopy. CSF samples from TBM patients and non-TBM persons were compared, and the sensitivity, specificity, accuracy, positive predictive value reached 83.6%, 69.8%, 77.2%, 76.1% respectively. Our work indicated investigation of CSF using UV-Vis absorption spectroscopy might become a potentially useful method for TBM diagnosis.

  5. Preliminary Shielding Analysis for HCCB TBM Transport

    NASA Astrophysics Data System (ADS)

    Miao, Peng; Zhao, Fengchao; Cao, Qixiang; Zhang, Guoshu; Feng, Kaiming

    2015-09-01

    A preliminary shielding analysis on the transport of the Chinese helium cooled ceramic breeder test blanket module (HCCB TBM) from France back to China after being irradiated in ITER is presented in this contribution. Emphasis was placed on irradiation safety during transport. The dose rate calculated by MCNP/4C for the conceptual package design satisfies the relevant dose limits from IAEA that the dose rate 3 m away from the surface of the package containing low specific activity III materials should be less than 10 mSv/h. The change with location and the time evolution of dose rates after shutdown have also been studied. This will be helpful for devising the detailed transport plan of HCCB TBM back to China in the near future. supported by the Major State Basic Research Development Program of China (973 Program) (No. 2013GB108000)

  6. Must we use ferritic steel in TBM?

    SciTech Connect

    Salavy, Jean-Francois; Boccaccini, Lorenzo V.; Chaudhuri, Paritosh; Cho, Seungyon; Enoeda, Mikio; Giancarli, Luciano; Kurtz, Richard J.; Luo, Tian Y.; Rao, K. Bhanu Sankara; Wong, Clement

    2010-12-13

    Mock-ups of DEMO breeding blankets, called Test Blanket Modules (TBMs), inserted and tested in ITER in dedicated equatorial ports directly facing the plasma, are expected to provide the first experimental answers on the necessary performance of the corresponding DEMO breeding blankets. Several DEMO breeding blanket designs have been studied and assessed in the last 20 years. At present, after considering various coolant and breeder combinations, all the TBM concepts proposed by the seven ITER Parties use Reduced-Activation Ferritic/Martensitic (RAFM) steel as the structural material. In order to perform valuable tests in ITER, the TBMs are expected to use the same structural material as corresponding DEMO blankets. However, due to the fact that this family of steels is ferromagnetic, their presence in the ITER vacuum vessel will create perturbations of the ITER magnetic fields that could reduce the quality of the plasma confinement during H-mode. As a consequence, a legitimate question has been raised on the necessity of using RAFM steel for TBMs structural material in ITER. By giving a short description of the main TBM testing objectives in ITER and assessing the consequences of not using such a material, this paper gives a comprehensive answer to this question. According to the working group author of the study, the use of RAFM steel as structural material for TBM is judged mandatory.

  7. Neutronic Calculation Analysis for CN HCCB TBM-Set

    NASA Astrophysics Data System (ADS)

    Cao, Qixiang; Zhao, Fengchao; Zhao, Zhou; Wu, Xinghua; Li, Zaixin; Wang, Xiaoyu; Feng, Kaiming

    2015-07-01

    Using the Monte Carlo transport code MCNP, neutronic calculation analysis for China helium cooled ceramic breeder test blanket module (CN HCCB TBM) and the associated shield block (together called TBM-set) has been carried out based on the latest design of HCCB TBM-set and C-lite model. Key nuclear responses of HCCB TBM-set, such as the neutron flux, tritium production rate, nuclear heating and radiation damage, have been obtained and discussed. These nuclear performance data can be used as the basic input data for other analyses of HCCB TBM-set, such as thermal-hydraulics, thermal-mechanics and safety analysis. supported by the Major State Basic Research Development Program of China (973 Program) (No. 2013GB108000)

  8. Occupational Radiation Exposure Analysis of US ITER DCLL TBM

    SciTech Connect

    Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad

    2007-08-01

    This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

  9. TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Morris, J.P.; Hansmire, W.H. |

    1995-03-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long-term, high-level nuclear waste repository in the United States. The current status of this long-term project from the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF) Tunnel, which is being excavated with a 7.6 m (25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3.0 to 7.6 m (10 to 25 ft). Prior to construction, extensive constructability reviews were an interactive part of the final design. The intent was to establish a constructable design that met the long-term stability requirements for radiological safety of a future repository, while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  10. Review of accidental safety studies for the European HCPB test blanket system

    NASA Astrophysics Data System (ADS)

    Boccaccini, L. V.; Ciattaglia, S.; Meyder, R.; Jin, X.

    2007-07-01

    This paper presents a review of safety studies for accidental sequences in the European solid breeder test blanket module (TBM) system. These studies are the starting point for the Preliminary Safety Analysis Report of ITER, under preparation to get the construction permit first and then later the operation licence. In general the reduced inventory of activation products and tritium associated with the TBM system makes the impact of this test system almost negligible on the overall safety risk of ITER. Nevertheless, the possibility of jeopardizing the ITER safety concept has been analysed in connection to the consequences of specific accident sequences, e.g. the pressurization of the vacuum vessel due to the He coolant blow-down, the hydrogen production from the Be-steam reaction, the possible interconnection between the port cell and the vacuum vessel causing air ingress and the necessity to assure heat removal in the short and long periods. In the frame of this assessment, three LOCA sequences have been selected as representative of accidents judged to cover all scenarios envisaged in Cat II to IV events involving the TBM, namely, in-vessel LOCA, ex-vessel LOCA and in-box LOCA.

  11. TBM tunnel friction values for the Grizzly Powerhouse Project

    SciTech Connect

    Stutsman, R.D.; Rothfuss, B.D.

    1995-12-31

    Tunnel boring machine (TBM) driven water conveyance tunnels are becoming increasingly more common. Despite advances in tunnel engineering and construction technology, hydraulic performance data for TBM driven tunnels remains relatively unavailable. At the Grizzly Powerhouse Project, the TBM driven water conveyance tunnel was designed using friction coefficients developed from a previous PG&E project. A range of coefficients were selected to bound the possible hydraulic performance variations of the water conveyance system. These friction coefficients, along with the water conveyance systems characteristics, and expected turbine characteristics, were used in a hydraulic transient analysis to determine the expected system pressure fluctuations, and surge chamber performance. During startup test data, these performance characteristics were measured to allow comparison to the original design assumptions. During construction of the tunnel, plaster casts were made of the actual excavated tunnel unlined and fiber reinforced shotcrete lined surfaces. These castings were used to measure absolute roughness of the surfaces so that a friction coefficient could be developed using the Moody diagram and compare them against the design values. This paper compares the assumed frictional coefficient with computed coefficients from headlosses measured during startup testing, and plaster cast measurement calculations. In addition, a comparison of coefficients will be presented for an other TBM driven water conveyance tunnel constructed in the 1980`s.

  12. 75 FR 16660 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ...-064-AD; Amendment 39-16252; AD 2010-07-07] RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM..., 2010 (75 FR 89). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI... air commerce by prescribing regulations for practices, methods, and procedures the Administrator...

  13. 75 FR 13239 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM... methods: Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions for... practices, methods, and procedures the Administrator finds necessary for safety in air commerce....

  14. 76 FR 30295 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-25

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM... proposed AD by July 11, 2011. ADDRESSES: You may send comments by any of the following methods: Federal e... air commerce by prescribing regulations for practices, methods, and procedures the Administrator...

  15. 76 FR 4216 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ...-041-AD; Amendment 39-16575; AD 2011-02-02] RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM... (73 FR 54067, September 18, 2008), the Director of the Federal Register approved the incorporation by... September 28, 2010 (75 FR 59658), and proposed to supersede AD 2008-19-06, Amendment 39- 15673 (73 FR...

  16. 75 FR 59658 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM... may send comments by any of the following methods: Federal eRulemaking Portal: Go to http://www... proposed AD. Discussion On September 8, 2008, we issued AD 2008-19-06, Amendment 39-15673 (73 FR...

  17. 75 FR 89 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; SOCATA Model TBM... following methods: Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions..., methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation...

  18. 75 FR 30272 - Airworthiness Directives; SOCATA Model TBM 700 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ... to the specified products. That NPRM was published in the Federal Register on March 19, 2010 (75 FR... Order 12866; (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034... or carried on certain TBM700 aeroplanes. The contaminated nature of this gas, when used against...

  19. Seismic source characterisation of a Tunnel Boring Machine (TBM)

    NASA Astrophysics Data System (ADS)

    Kreutzer, Ingrid; Brückl, Ewald; Radinger, Alexander

    2015-04-01

    The Tunnel Seismic While Drilling (TSWD) method aims at predicting continuously the geological situation ahead of the tunnel without disturbing the construction work. Thereby the Tunnel Boring Machine (TBM) itself is used as seismic source. The cutting process generates seismic waves radiating into the rock mass and vibrations propagating to the main bearing of the cutter head. These vibrations are monitored and used as pilot signal. For the processing and interpretation it was hypothesized so far that the TBM acts like a single force. To prove this assumption the radiation pattern of several TBM's under construction were investigated. Therefore 3-components geophones were installed at the surface, which were situated directly above the tunnel axes and also with lateral offset. Additional, borehole geophones were placed in the wall of one tube of a two-tube tunnel. The geophones collected the forward and backward radiated wave field, as the TBM, operating in the other tube, passed their positions. The obtained seismic data contains continuous records over a range of 600 m of the TBM position. The offsets vary from 25 m to 400 m and the frequency ranges from 20-250 Hertz. The polarisation of the p-wave and the s-wave and their amplitude ratio were determined and compared with modelled seismograms with different source mechanism. The results show that the description of the source mechanism by a single force can be used as a first order approximation. More complex radiation pattern including tensile forces and several source locations like the transmission of reaction forces over the gripper to the tunnel wall are further tested and addressed.

  20. Ground Motion Relations While TBM Drilling in Unconsolidated Sediments

    NASA Astrophysics Data System (ADS)

    Grund, Michael; Ritter, Joachim R. R.; Gehrig, Manuel

    2016-05-01

    The induced ground motions due to the tunnel boring machine (TBM), which has been used for the drilling of the urban metro tunnel in Karlsruhe (SW Germany), has been studied using the continuous recordings of seven seismological monitoring stations. The drilling has been undertaken in unconsolidated sediments of the Rhine River system, relatively close to the surface at 6-20 m depth and in the vicinity of many historic buildings. Compared to the reference values of DIN 4150-3 (1-80 Hz), no exceedance of the recommended peak ground velocity (PGV) limits (3-5 mm/s) was observed at the single recording site locations on building basements during the observation period between October 2014 and February 2015. Detailed analyses in the time and frequency domains helped with the detection of the sources of several specific shaking signals in the recorded time series and with the comparison of the aforementioned TBM-induced signals. The amplitude analysis allowed for the determination of a PGV attenuation relation (quality factor Q ~ 30-50) and the comparison of the TBM-induced ground motion with other artificially induced and natural ground motions of similar amplitudes.

  1. Re-analysis of HCPB/HCLL Blanket Mock-up Experiments Using Recent Nuclear Data Libraries

    NASA Astrophysics Data System (ADS)

    Kondo, K.; Fischer, U.; Klix, A.; Pereslavtsev, P.; Serikov, A.; Villari, R.

    2014-06-01

    We have re-analysed the two breeding blankets experiments performed previously in the frame of the European fusion program on two mock-ups of the European Helium-Cooled-Lithiium Lead (HCLL) and Helium-Cooled-Pebble-Bed (HCPB) test blanket modules for ITER. The tritium production rate and the neutron and photon spectra measured in these mock-ups were compared with calculations using FENDL-3 Starter Library, release 4 and state-of-the-art nuclear data evaluations, JEFF-3.1.2, JENDL-4.0 and ENDF/B-VII.0. The tritium production calculated for the HCPB mock-up underestimates the experimental result by about 10%. The result calculated with FENDL-3/SLIB4 gives slightly smaller tritium production by 2% than the one with FENDL-2.1. The difference attributes to the slight modification of the total and elastic scattering cross section of Be. For the HCLL experiment, all libraries reproduce the experimental results well. FENDL-3/SLIB4 gives better result both for the measured spectra and the tritium production compared to FENDL-2.1.

  2. Re-analysis of HCPB/HCLL Blanket Mock-up Experiments Using Recent Nuclear Data Libraries

    SciTech Connect

    Kondo, K.; Fischer, U.; Klix, A.; Pereslavtsev, P.; Serikov, A.; Villari, R.

    2014-06-15

    We have re-analysed the two breeding blankets experiments performed previously in the frame of the European fusion program on two mock-ups of the European Helium-Cooled-Lithiium Lead (HCLL) and Helium-Cooled-Pebble-Bed (HCPB) test blanket modules for ITER. The tritium production rate and the neutron and photon spectra measured in these mock-ups were compared with calculations using FENDL-3 Starter Library, release 4 and state-of-the-art nuclear data evaluations, JEFF-3.1.2, JENDL-4.0 and ENDF/B-VII.0. The tritium production calculated for the HCPB mock-up underestimates the experimental result by about 10%. The result calculated with FENDL-3/SLIB4 gives slightly smaller tritium production by 2% than the one with FENDL-2.1. The difference attributes to the slight modification of the total and elastic scattering cross section of Be. For the HCLL experiment, all libraries reproduce the experimental results well. FENDL-3/SLIB4 gives better result both for the measured spectra and the tritium production compared to FENDL-2.1.

  3. The use of a Tunnel Boring Machine (TBM) as a seismic source

    NASA Astrophysics Data System (ADS)

    Kreutzer, Ingrid; Chwatal, Werner; Radinger, Alexander; Brückl, Ewald

    2014-05-01

    The Tunnel Seismic While Drilling (TSWD) method uses the Tunnel Boring Machine (TBM) as the seismic source. The method has been developed to predict the geological situation from reflections ahead of the tunnel face without disturbing the tunneling. The vibrations of the TBM are continuously monitored near the drilling head (pilot signal) as well as the direct and reflected seismic wave field at borehole geophones (geophone signal) situated in the tunnel wall behind the TBM. During the processing these signals are correlated and result in excellent seismic traces comparable to conventional seismic methods. The interpretation of the reflections leads to a nearly daily prognosis about 100 m ahead of the TBM. This system was successfully implemented at three different construction sites in Austria and is currently operating at one further. The cutters on front of the TBM head are pressed against the tunnel face and split the rock during rotating which is called the chipping process. This cutting process generates seismic waves radiated into the rock mass and results also in vibrations of the TBM itself. On the one hand it is important to know the source mechanism of the TBM and the radiation pattern of the seismic waves in all directions. Until now this is not well understood. To investigate this 3C-geophones were installed at the surface above the tunnel axis at different construction sites. The obtained seismograms show the forward and backward radiated seismic wave field of the TBM, for the present without consideration of the influence of the free surface. We compare this data with modelled seismograms in which we use different possible source mechanism, like single force or force due to tensile cracks. First results are shown in the scope of this work. On the other hand it is essential to know how good the recorded pilot signal represents the entire chipping process. Due to technically reasons the pilot signal has been registered so far on the non-rotating part

  4. YUCCA MOUNTAIN SITE CHARACTERIZATIONS PROJECT TUNNEL BORING MACHINE (TBM) SYSTEM SAFETY ANALYSIS

    SciTech Connect

    N /A

    1997-02-19

    The purpose of this analysis is to systematically identify and evaluate hazards related to the tunnel boring machine (TBM) used in the Exploratory Studies Facility (ESF) at the Yucca Mountain Site Characterization Project. This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. Since the TBM is an ''as built'' system, the M&O is conducting the System Safety Analysis during the construction or assembly phase of the TBM. A largely qualitative approach was used since a radiological System Safety Analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the TBM in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the system/subsystem/component design, (2) add safety features and capabilities to existing designs, and (3) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions. The scope of this analysis is limited to the TBM during normal operations, excluding hazards occurring during assembly and test of the TBM or maintenance of the TBM equipment.

  5. A PRELIMINARY ASSESSMENT OF THE OCCUPATIONAL RADIATION EXPOSURE FROM MAINTAINING THE US ITER DCLL TBM

    SciTech Connect

    B. J. Merrill; L. C. Cadwallader; M. Dagher

    2008-09-01

    This paper details an Occupational Radiation Exposure (ORE) analysis performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This ORE analysis was performed with the QADMOD dose code for maintenance activities anticipated for the US DCLL TBM concept and its ancillary systems. Identification of the maintenance tasks that will have to be performed and estimates of the time required to perform these tasks were developed based on either expert opinion or on industrial maintenance experience for similar technologies. This paper details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

  6. TBM tunneling on the Yucca Mountain Project: Proceedings

    SciTech Connect

    Williamson, G.E.; Gowring, I.M.

    1995-07-01

    The US Department of Energy`s (DOE) Yucca Mountain Project (YMP) is a scientific endeavor to determine the suitability of Yucca Mountain for the first long term, high level nuclear waste repository in the United States. Status of this long-term project form the construction perspective is described. A key element is construction of the Exploratory Studies Facility (ESF), which is being excavated with a 7. 6 m(25 ft) diameter tunnel boring machine (TBM). Development of the ESF may include the excavation of over 15 km (9.3 mi) of tunnel varying in size from 3 to 7.6 m(10 to 25 ft). Prior to construction, extensive constructibility reviews were an interactive part of the final design. Intent was to establish a constructible design that met the long-term stability requirements for radiological safety of a future repository while maintaining flexibility for the scientific investigations and acceptable tunneling productivity.

  7. The Interaction Between Shield, Ground and Tunnel Support in TBM Tunnelling Through Squeezing Ground

    NASA Astrophysics Data System (ADS)

    Ramoni, M.; Anagnostou, G.

    2011-01-01

    When planning a TBM drive in squeezing ground, the tunnelling engineer faces a complex problem involving a number of conflicting factors. In this respect, numerical analyses represent a helpful decision aid as they provide a quantitative assessment of the effects of key parameters. The present paper investigates the interaction between the shield, ground and tunnel support by means of computational analysis. Emphasis is placed on the boundary condition, which is applied to model the interface between the ground and the shield or tunnel support. The paper also discusses two cases, which illustrate different methodical approaches applied to the assessment of a TBM drive in squeezing ground. The first case history—the Uluabat Tunnel (Turkey)—mainly involves the investigation of TBM design measures aimed at reducing the risk of shield jamming. The second case history—the Faido Section of the Gotthard Base Tunnel (Switzerland)—deals with different types of tunnel support installed behind a gripper TBM.

  8. The Effect of Consolidation on TBM Shield Loading in Water-Bearing Squeezing Ground

    NASA Astrophysics Data System (ADS)

    Ramoni, M.; Anagnostou, G.

    2011-01-01

    Jamming or overstressing of the shield due to ground pressure are potential problems for tunnel boring machine (TBM) tunnelling in squeezing ground. The risk of shield jamming depends essentially on the deformation rate of the ground in the vicinity of the working face. The time-dependency of the ground response to the excavation is associated with its rheological properties as well as with the transient consolidation process that takes place around the opening in the case of a low-permeability saturated ground. The present paper focuses on the second mechanism and investigates the interaction between the advancing shield, tunnel lining and consolidating ground by means of transient numerical analyses. For a given set of geotechnical conditions and a given TBM configuration, the load exerted by the ground upon the shield during TBM operation decreases with increasing gross advance rate. During a long break in operations, the ground pressure may increase significantly, thereby necessitating a higher thrust force to overcome shield skin friction and restart the TBM. It is interesting to note that a high advance rate reduces the risk of shield jamming not only during TBM advance, but is also favourable with respect to any subsequent long standstills.

  9. Influence of Corrosion on the Abrasion of Cutter Steels Used in TBM Tunnelling

    NASA Astrophysics Data System (ADS)

    Espallargas, N.; Jakobsen, P. D.; Langmaack, L.; Macias, F. J.

    2015-01-01

    Abrasion on tunnel boring machine (TBM) cutters may be critical in terms of project duration and costs. Several researchers are currently studying the degradation of TBM cutter tools used for excavating hard rock, soft ground and loose soil. So far, the primary focus of this research has been directed towards abrasive wear. Abrasive wear is a very common process in TBM excavation, but with a view to the environment in which the tools are working, corrosion may also exert an influence. This paper presents a selection of techniques that can be used to evaluate the influence of corrosion on abrasion on TBM excavation tools. It also presents the influence of corrosion on abrasive wear for some initial tests, with constant steel and geomaterial and varying properties of the excavation fluids (soil conditioners, anti-abrasion additives and water). The results indicate that the chloride content in the water media greatly influences the amount of wear, providing evidence of the influence of corrosion on the abrasion of the cutting tools. The presence of conditioning additives tailored to specific rock or soil conditions reduces wear. However, when chloride is present in the water, the additives minimise wear rates but fail to suppress corrosion of the cutting tools.

  10. Analysis on the Rock-Cutter Interaction Mechanism During the TBM Tunneling Process

    NASA Astrophysics Data System (ADS)

    Yang, Haiqing; Wang, He; Zhou, Xiaoping

    2016-03-01

    The accurate prediction of rock cutting forces of disc cutters is crucial for tunnel boring machine (TBM) design and construction. Disc cutter wear, which affects TBM penetration performance, has frequently been found at TBM sites. By considering the operating path and wear of the disc cutter, a new model is proposed for evaluating the cutting force and wear of the disc cutter in the tunneling process. The circular path adopted herein, which is the actual running path of the TBM disc cutter, shows that the lateral force of the disc cutter is asymmetric. The lateral forces on the sides of the disc cutter are clearly different. However, traditional solutions are obtained by assuming a linear path, where the later forces are viewed as equal. To simulate the interaction between the rock and disc cutter, a simple brittle damage model for rock mass is introduced here. Based on the explicit dynamic finite element method, the cutting force acting on the rock generated by a single disc cutter is simulated. It is shown that the lateral cutting force of the disc cutter strongly affects the wear extent of disc cutter. The wear mechanism is thus underestimated by the classical model, which was obtained by linear cutting tests. The simulation results are discussed and compared with other models, and these simulation results agree well with the results of present ones.

  11. Design and tritium permeation analysis of China HCCB TBM port cell

    SciTech Connect

    Jiangfeng, S.; Guoqiang, H.; Zhiyong, H.; Chang'an, C.; Deli, L.

    2015-03-15

    China is planning to develop a helium-cooled ceramic breeder (HCCB) test blanket module (TBM) on ITER to test key blanket technologies. In this paper, the design and tritium permeation analysis of China HCCB TBM port cell are introduced. A theoretical model has been developed to estimate tritium permeation rates and leak rates from the components and pipes which China has scheduled to house in the port cell. It is shown that on normal working conditions, the permeation and leak rate of the systems in the port cell will be no higher than 1.58 Ci/d without the use of tritium permeation barriers, and 0.10 Ci/d with the use of tritium permeation barriers. It also appears that tritium permeation barriers are necessary for high temperature components such as the reduction bed and the heater.

  12. TBM performance prediction in Yucca Mountain welded tuff from linear cutter tests

    SciTech Connect

    Gertsch, R.; Ozdemir, L.; Gertsch, L.

    1992-11-01

    This paper discusses performance prediction which were developed for tunnel boring machines operating in welded tuff for the construction of the experimental study facility and the potential nuclear waste repository at Yucca Mountain. The predictions were based on test data obtained from an extensive series of linear cutting tests performed on samples of Topopah String welded tuff from the Yucca Mountain Project site. Using the cutter force, spacing, and penetration data from the experimental program, the thrust, torque, power, and rate of penetration were estimated for a 25 ft diameter tunnel boring machine (TBM) operating in welded tuff. The result show that the Topopah Spring welded tuff (TSw2) can be excavated at relatively high rates of advance with state-of-the-art TBMs. The result also show, however, that the TBM torque and power requirements will be higher than estimated based on rock physical properties and past tunneling experience in rock formations of similar strength.

  13. Experimental neutronics tests for a neutron activation system for the European ITER TBM

    SciTech Connect

    Klix, A.; Fischer, U.; Gehre, D.; Kleizer, G.; Raj, P.; Rovni, I.; Ruecker, Tom

    2014-08-21

    We are investigating methods for neutron flux measurement in the ITER TBM. In particular we have tested sets of activation materials leading to induced gamma activities with short half-lives of the order of tens of seconds up to minutes and standard activation materials. Packages of activation foils have been irradiated with the intense neutron generator of Technical University of Dresden in a pure DT neutron field as well as in a neutronics mock-up of the European ITER HCLL TBM. An important aim was to check whether the gamma activity induced in the activation foils in these packages could be measured simultaneously. It was indeed possible to identify gamma lines of interest in gamma-ray measurements immediately after extraction from the irradiation.

  14. Impact of Advance Rate on Entrapment Risk of a Double-Shielded TBM in Squeezing Ground

    NASA Astrophysics Data System (ADS)

    Hasanpour, Rohola; Rostami, Jamal; Barla, Giovanni

    2015-05-01

    Shielded tunnel boring machines (TBMs) can get stuck in squeezing ground due to excessive tunnel convergence under high in situ stress. This typically coincides with extended machine stoppages, when the ground has sufficient time to undergo substantial displacements. Excessive convergence of the ground beyond the designated overboring means ground pressure against the shield and high shield frictional resistance that, in some cases, cannot be overcome by the TBM thrust system. This leads to machine entrapment in the ground, which causes significant delays and requires labor-intensive and risky operations of manual excavation to release the machine. To evaluate the impact of the time factor on the possibility of machine entrapment, a comprehensive 3D finite difference simulation of a double-shielded TBM in squeezing ground was performed. The modeling allowed for observation of the impact of the tunnel advance rate on the possibility of machine entrapment in squeezing ground. For this purpose, the model included rock mass properties related to creep in severe squeezing conditions. This paper offers an overview of the modeling results for a given set of rock mass and TBM parameters, as well as lining characteristics, including the magnitude of displacement and contact forces on shields and ground pressure on segmental lining versus time for different advance rates.

  15. A spatial estimation model for continuous rock mass characterization from the specific energy of a TBM

    NASA Astrophysics Data System (ADS)

    Exadaktylos, G.; Stavropoulou, M.; Xiroudakis, G.; de Broissia, M.; Schwarz, H.

    2008-12-01

    Basic principles of the theory of rock cutting with rolling disc cutters are used to appropriately reduce tunnel boring machine (TBM) logged data and compute the specific energy (SE) of rock cutting as a function of geometry of the cutterhead and operational parameters. A computational code written in Fortran 77 is used to perform Kriging predictions in a regular or irregular grid in 1D, 2D or 3D space based on sampled data referring to rock mass classification indices or TBM related parameters. This code is used here for three purposes, namely: (1) to filter raw data in order to establish a good correlation between SE and rock mass rating (RMR) (or tunnelling quality index Q) along the chainage of the tunnel, (2) to make prediction of RMR, Q or SE along the chainage of the tunnel from boreholes at the exploration phase and design stage of the tunnel, and (3) to make predictions of SE and RMR or Q ahead of the tunnel’s face during excavation of the tunnel based on SE estimations during excavation. The above tools are the basic constituents of an algorithm to continuously update the geotechnical model of the rock mass based on logged TBM data. Several cases were considered to illustrate the proposed methodology, namely: (a) data from a system of twin tunnels in Hong Kong, (b) data from three tunnels excavated in Northern Italy, and (c) data from the section Singuerlin-Esglesias of the Metro L9 tunnel in Barcelona.

  16. TBM Performance Analysis in Pyroclastic Rocks: A Case History of Karaj Water Conveyance Tunnel

    NASA Astrophysics Data System (ADS)

    Hassanpour, J.; Rostami, J.; Khamehchiyan, Mashalah; Bruland, A.; Tavakoli, H. R.

    2010-07-01

    Karaj Water Conveyance Tunnel (KWCT) is 30-km long and has been designed for transferring 16 m3/s of water from Amir-Kabir dam to northwest of Tehran. Lot No. 1 of this long tunnel, with a length of 16 km, is under construction with a double shield TBM and currently about 8.7 km of the tunnel has been excavated/lined. This paper will offer an overview of the project, concentrating on the TBM operation and will review the results of field performance of the machine. In addition to analysis of the available data including geological and geotechnical information and machine operational parameters, actual penetration and advance rates will be compared to the estimated machine performance using prediction models, such as CSM, NTNU and QTBM. Also, results of analysis to correlate TBM performance parameters to rock mass characteristics will be discussed. This involves statistical analysis of the available data to develop new empirical methods. The preliminary results of this study revealed that the available prediction models need some corrections or modifications to produce a more accurate prediction in geological conditions of this particular project.

  17. Prediction of Brittle Failure for TBM Tunnels in Anisotropic Rock: A Case Study from Northern Norway

    NASA Astrophysics Data System (ADS)

    Dammyr, Øyvind

    2016-06-01

    Prediction of spalling and rock burst is especially important for hard rock TBM tunneling, because failure can have larger impact than in a drill and blast tunnel and ultimately threaten excavation feasibility. The majority of research on brittle failure has focused on rock types with isotropic behavior. This paper gives a review of existing theory and its application before a 3.5-m-diameter TBM tunnel in foliated granitic gneiss is used as a case to study brittle failure characteristics of anisotropic rock. Important aspects that should be considered in order to predict brittle failure in anisotropic rock are highlighted. Foliation is responsible for considerable strength anisotropy and is believed to influence the preferred side of v-shaped notch development in the investigated tunnel. Prediction methods such as the semi- empirical criterion, the Hoek- Brown brittle parameters, and the non-linear damage initiation and spalling limit method give reliable results; but only as long as the angle between compression axis and foliation in uniaxial compressive tests is relevant, dependent on the relation between tunnel trend/plunge, strike/dip of foliation, and tunnel boundary stresses. It is further demonstrated that local in situ stress variations, for example, due to the presence of discontinuities, can have profound impact on failure predictions. Other carefully documented case studies into the brittle failure nature of rock, in particular anisotropic rock, are encouraged in order to expand the existing and relatively small database. This will be valuable for future TBM planning and construction stages in highly stressed brittle anisotropic rock.

  18. Accelerated vs. unaccelerated serial MRI based TBM-SyN measurements for Clinical Trials in Alzheimer’s disease

    PubMed Central

    Vemuri, Prashanthi; Senjem, Matthew L.; Gunter, Jeffrey L.; Lundt, Emily S.; Tosakulwong, Nirubol; Weigand, Stephen D.; Borowski, Bret J.; Bernstein, Matt A.; Zuk, Samantha M.; Lowe, Val J.; Knopman, David S.; Petersen, Ronald C.; Fox, Nick C.; Thompson, Paul M.; Weiner, Michael W.; Jack, Clifford R.

    2015-01-01

    Objective Our primary objective was to compare the performance of unaccelerated vs. accelerated structural MRI for measuring disease progression using serial scans in Alzheimer’s disease (AD). Methods We identified cognitively normal (CN), early mild cognitive impairment (EMCI), late mild cognitive impairment (LMCI) and AD subjects from all available Alzheimer’s Disease Neuroimaging Initiative (ADNI) subjects with usable pairs of accelerated and unaccelerated scans. There were a total of 696 subjects with baseline and 3 month scans, 628 subjects with baseline and 6 month scans and 464 subjects with baseline and 12 month scans available. We employed the Symmetric Diffeomorphic Image Normalization method (SyN) for normalization of the serial scans to obtain Tensor Based Morphometry (TBM) maps which indicate the structural changes between pairs of scans. We computed a TBM-SyN summary score of annualized structural changes over 31 regions of interest (ROIs) that are characteristically affected in AD. TBM-SyN scores were computed using accelerated and unaccelerated scan pairs and compared in terms of agreement, group-wise discrimination, and sample size estimates for a hypothetical therapeutic trial. Results We observed a number of systematic differences between TBM-SyN scores computed from accelerated and unaccelerated pairs of scans. TBM-SyN scores computed from accelerated scans tended to have overall higher estimated values than those from unaccelerated scans. However, the performance of accelerated scans was comparable to unaccelerated scans in terms of discrimination between clinical groups and sample sizes required in each clinical group for a therapeutic trial. We also found that the quality of both accelerated vs. unaccelerated scans were similar. Conclusions Accelerated scanning protocols reduce scan time considerably. Their group-wise discrimination and sample size estimates were comparable to those obtained with unaccelerated scans. The two protocols did

  19. TIG and HIP joining of Reduced Activation Ferrite/Martensitic steel for the Korean ITER-TBM

    NASA Astrophysics Data System (ADS)

    Ku, Duck Young; Oh, Seungjin; Ahn, Mu-Young; Yu, In-Keun; Kim, Duck-Hoi; Cho, Seungyon; Choi, Im-Sub; Kwon, Ki-Bum

    2011-10-01

    Korea is developing a Helium Cooled Solid Breeder Test Blanket Module for ITER. The primary candidate structural material is a Reduced Activation Ferritic/Martensitic steel. The complex TBM structure requires developing joining technologies for successful fabrication. The characteristics of Tungsten Inert Gas welding and Hot Isostatic Pressing joining of RAFM steel were investigated. Metallurgical examinations showed that the steel grain size was increased after HIP joining and recovered by post joining heat treatment. Both TIG welding and HIP joining are found to be acceptable for ITER TBM based on mechanical tests and microstructure examination.

  20. Application of quality assurance controls to TBM tunneling on the Yucca Mountain Project

    SciTech Connect

    Christensen, J.D.

    1996-06-01

    As part of the Yucca Mountain Project (YMP), a 7.62-meter diameter tunnel is being constructed using a Tunnel Boring Machine (TBM). This tunnel, which may form a portion of a permanent high-level nuclear waste repository, is being constructed under the auspices of a nuclear quality assurance (QA) program. The YMP nuclear QA program applies to items and activities determined to be important to radiological safety, waste isolation, and potential interactions with the environment. The items and activities determined to be important have been assigned a quality assurance classification. This paper focuses on the items (rockbolts, steel sets, and shotcrete) and quality affecting activities involved in providing ground support and excavating the tunnel. Typical activities that have been assigned QA classifications include TBM maintenance, control of water used in the tunnel during construction, and control of diesel emissions in the tunnel. The paper concludes that the key to the successful implementation of nuclear QA requirements for tunneling at Yucca Mountain was the assignment of personnel with the appropriate mix of tunneling and nuclear experience.

  1. Analysis of MHD Pressure Drop in Liquid LiPb Flow in Chinese ITER DFLL-TBM with Insulating Coating

    NASA Astrophysics Data System (ADS)

    Chen, Hongli; Zhou, Tao; Wang, Hongyan

    2008-08-01

    Magnetohydrodynamic (MHD) pressure drop in the Chinese Dual Functional Liquid Lithium-lead Test Blanket Module (DFLL-TBM) proposed for ITER is discussed in this paper. Electrical insulation between the coolant channel surfaces and the liquid metal is required to reduce the MHD pressure drop to a manageable level. Insulation can be provided by a thin insulating coating, such as Al2O3, which can also serve as a tritium barrier layer, at the channel surfaces in contact with LiPb. The coating's effectiveness for reducing the MHD pressure drop is analysed through three-dimensional numerical simulation. A MHD-based commercial computational fluid dynamic (CFD) software FLUENT is used to simulate the LiPb flow. The effect on the MHD pressure drop due to cracks or faults in the coating layer is also considered. The insulating performance requirement for the coating material in DFLL-TBM design is proposed according to the analysis.

  2. Laboratory tests to study the influence of rock stress confinement on the performances of TBM discs in tunnels

    NASA Astrophysics Data System (ADS)

    Innaurato, N.; Oggeri, C.; Oreste, P.; Vinai, R.

    2011-06-01

    To clarify some aspects of rock destruction with a disc acting on a high confined tunnel face, a series of tests were carried out to examine fracture mechanisms under an indenter that simulates the tunnel boring machine (TBM) tool action, in the presence of an adjacent groove, when a state of stress (lateral confinement) is imposed on a rock sample. These tests proved the importance of carefully establishing the optimal distance of grooves produced by discs acting on a confined surface, and the value (as a mere order of magnitude) of the increase of the thrust to produce the initiation of chip formation, as long as the confinement pressure becomes greater.

  3. Proposed damage evolution model for large-scale finite element modeling of the dual coolant US-ITER TBM

    NASA Astrophysics Data System (ADS)

    Sharafat, S.; El-Awady, J.; Liu, S.; Diegele, E.; Ghoniem, N. M.

    2007-08-01

    Large-scale finite element modeling (FEM) of the US Dual Coolant Lead Lithium ITER Test Blanket Module including damage evolution is under development. A comprehensive rate-theory based radiation damage creep deformation code was integrated with the ABACUS FEM code. The advantage of this approach is that time-dependent in-reactor deformations and radiation damage can now be directly coupled with 'material properties' of FEM analyses. The coupled FEM-Creep damage model successfully simulated the simultaneous microstructure and stress evolution in small tensile test-bar structures. Applying the integrated Creep/FEM code to large structures is still computationally prohibitive. Instead, for thermo-structural analysis of the DCLL TBM structure the integrated FEM-creep damage model was used to develop true stress-strain behavior of F82H ferritic steel. Based on this integrated damage evolution-FEM approach it is proposed to use large-scale FEM analysis to identify and isolate critical stress areas for follow up analysis using detailed and fully integrated creep-FEM approach.

  4. SURFACE-BASED TBM BOOSTS POWER TO DETECT DISEASE EFFECTS ON THE BRAIN: AN N=804 ADNI STUDY

    PubMed Central

    Wang, Yalin; Song, Yang; Rajagopalan, Priya; An, Tuo; Liu, Krystal; Chou, Yi-Yu; Gutman, Boris; Toga, Arthur W.; Thompson, Paul M.

    2012-01-01

    Computational anatomy methods are now widely used in clinical neuroimaging to map the profile of disease effects on the brain and its clinical correlates. In Alzheimer’s disease (AD), many research groups have modeled localized changes in hippocampal and lateral ventricular surfaces, to provide candidate biomarkers of disease progression for drug trials. We combined the power of parametric surface modeling and tensor-based morphometry to study hippocampal differences associated with AD and mild cognitive impairment (MCI) in 490 subjects (97 AD, 245 MCI, 148 controls) and ventricular differences in 804 subjects scanned as part of the Alzheimer’s Disease Neuroimaging Initiative (ADNI; 184 AD, 391 MCI, 229 controls). We aimed to show that a new multivariate surface statistic based on multivariate tensor-based morphometry (mTBM) and radial distance provides a more powerful way to detect localized anatomical differences than conventional surface-based analysis. In our experiments, we studied correlations between hippocampal atrophy and ventricular enlargement and clinical measures and cerebrospinal fluid biomarkers. The new multivariate statistics gave better effect sizes for detecting morphometric differences, relative to other statistics including radial distance, analysis of the surface tensor and the Jacobian determinant. In empirical tests using false discovery rate curves, smaller sample sizes were needed to detect associations with diagnosis. The analysis pipeline is generic and automated. It may be applied to analyze other brain subcortical structures including the caudate nucleus and putamen. This publically available software may boost power for morphometric studies of subcortical structures in the brain. PMID:21440071

  5. Eu doping and reduction into barium orthophosphates

    NASA Astrophysics Data System (ADS)

    Santos, Ricardo D. S.; dos S. Rezende, Marcos V.

    2016-08-01

    We investigated Eu3+ and Eu2+ ion incorporation and the reduction of Eu3+ ions in a LiBaPO4 lattice using atomistic simulations based on lattice energy minimization. We predicted the most probable sites occupied by Eu3+ and Eu2+ ions, and the related charge-compensation mechanisms involved in these substitutions to the most provable reduction agent for Eu reduction. It was found that Eu3+and Eu2+ ions are the most energetically favorable for incorporation at Ba site. In the case of the Eu3+ ion, charge compensation by the LiBa‧ antisite is the most provable. Eu3+ reduction involving a H2 reduction atmosphere is the most favorable. Our results reveal that Eu3+ and Eu2+ position plays an important role in the luminescence characteristic and in the persistent luminescence mechanisms related to LiBaPO4.

  6. EU pharmaceutical expenditure forecast

    PubMed Central

    Urbinati, Duccio; Rémuzat, Cécile; Kornfeld, Åsa; Vataire, Anne-Lise; Cetinsoy, Laurent; Aballéa, Samuel; Mzoughi, Olfa; Toumi, Mondher

    2014-01-01

    Background and Objectives With constant incentives for healthcare payers to contain their pharmaceutical budgets, forecasting has become critically important. Some countries have, for instance, developed pharmaceutical horizon scanning units. The objective of this project was to build a model to assess the net effect of the entrance of new patented medicinal products versus medicinal products going off-patent, with a defined forecast horizon, on selected European Union (EU) Member States’ pharmaceutical budgets. This model took into account population ageing, as well as current and future country-specific pricing, reimbursement, and market access policies (the project was performed for the European Commission; see http://ec.europa.eu/health/healthcare/key_documents/index_en.htm). Method In order to have a representative heterogeneity of EU Member States, the following countries were selected for the analysis: France, Germany, Greece, Hungary, Poland, Portugal, and the United Kingdom. A forecasting period of 5 years (2012–2016) was chosen to assess the net pharmaceutical budget impact. A model for generics and biosimilars was developed for each country. The model estimated a separate and combined effect of the direct and indirect impacts of the patent cliff. A second model, estimating the sales development and the risk of development failure, was developed for new drugs. New drugs were reviewed individually to assess their clinical potential and translate it into commercial potential. The forecast was carried out according to three perspectives (healthcare public payer, society, and manufacturer), and several types of distribution chains (retail, hospital, and combined retail and hospital). Probabilistic and deterministic sensitivity analyses were carried out. Results According to the model, all countries experienced drug budget reductions except Poland (+€41 million). Savings were expected to be the highest in the United Kingdom (−€9,367 million), France

  7. Application of computational fluid dynamics for the simulation of cryogenic molecular sieve bed absorber of hydrogen isotopes recovery system for Indian LLCB-TBM

    SciTech Connect

    Gayathri Devi, V.; Sircar, A.; Sarkar, B.

    2015-03-15

    One of the most challenging tasks in the design of the fuel cycle system lies in the effective design of Tritium Extraction System (TES) which involves proper extraction and purification of tritium in the fuel cycle of the fusion reactor. Indian Lead Lithium cooled Ceramic Breeder Test Blanket Module (LLCB-TBM) would extract hydrogen isotopes through Cryogenic Molecular Sieve Bed (CMSB) adsorber system. A prototype Hydrogen Isotopes Recovery System (HIRS) is being developed to validate the concepts for tritium extraction by adsorption mass transfer mechanism. In this study, a design model has been developed and analyzed to simulate the adsorption mass transfer kinetics in a fixed bed adsorption column. The simulation leads primarily to effective design of HIRS, which is a state-of-the-art technology. The paper describes the process simulation approach and the results of Computational Fluid Dynamics (CFD) analysis. The effects of different operating conditions are studied to investigate their influence on the hydrogen isotopes adsorption capacity. The results of the present simulation study would be used to understand the best optimized transport phenomenon before realizing the TES as a system for LLCB-TBM. (authors)

  8. High heat flux test with HIP-bonded Ferritic Martensitic Steel mock-up for the first wall of the KO HCML TBM

    NASA Astrophysics Data System (ADS)

    Won Lee, Dong; Dug Bae, Young; Kwon Kim, Suk; Yun Shin, Hee; Guen Hong, Bong; Cheol Bang, In

    2011-10-01

    In order for a Korean Helium Cooled Molten Lithium (HCML) Test Blanket Module (TBM) to be tested in the International Thermonuclear Experimental Reactor (ITER), fabrication method for the TBM FW such as Hot Isostatic Pressing (HIP, 1050 °C, 100 MPa, 2 h) has been developed including post HIP heat treatment (PHHT, normalizing at 950 °C for 2 h and tempering at 750 °C for 2 h) with Ferritic Martensitic Steel (FMS). Several mock-ups were fabricated using the developed methods and one of them, three-channel mock-up, was used for performing a High Heat Flux (HHF) test to verify the joint integrity. Test conditions were determined using the commercial code, ANSYS-11, and the test was performed in the Korea Heat Load Test (KoHLT) facility, which was used a radiation heating with a graphite heater. The mock-up survived up to 1000 cycles under 1.0 MW/m 2 heat flux and there is no delamination or failure during the test.

  9. Biosimilar regulation in the EU.

    PubMed

    Kurki, Pekka; Ekman, Niklas

    2015-01-01

    In the EU, the EMA has been working with biosimilars since 1998. This experience is crystallized in the extensive set of guidelines, which range from basic principles to details of clinical trials. While the guidance may appear complicated, it has enabled the development of biosimilars, of which 21 have managed to get marketing authorization. Currently marketed biosimilars in the EU have a good track record in safety and traceability. No biosimilars have been withdrawn from the market because of safety concerns. The most controversial issues with biosimilars are immunogenicity and extrapolation of therapeutic indications. The available data for these topics do not raise concerns among EU regulators. Interchangeability and substitution are regulated by individual EU member states. PMID:26294076

  10. EU Space Awareness: Initial implemenation

    NASA Astrophysics Data System (ADS)

    Russo, Pedro

    2015-08-01

    EU Space Awareness uses the excitement of space to attract young people into science and technology and stimulate European and global citizenship. The project will show children and teenagers the opportunities offered by space science and engineering and inspire primary-school children when their curiosity is high and their value systems are being formed. EU Space Awareness, a 3-year project, has started in March 2015 with 10 partner organisations and 15 network nodes in 17 European countries and the IAU Office of Astronomy for Development. During this talk we will give a update about the intial implementation of the project and its relevant for astronomy for development.

  11. Quantitative analysis of Eu 2+ and Eu 3+ in LiCl-KCl eutectic melt by spectrophotometry and electrochemistry

    NASA Astrophysics Data System (ADS)

    Kim, Tack-Jin; Uehara, Akihiro; Nagai, Takayuki; Fujii, Toshiyuki; Yamana, Hajimu

    2011-02-01

    The redox behavior of Eu 2+ and Eu 3+ in the LiCl-KCl eutectic at 773 K was investigated. Since the equilibrium potential of the melt is very close to the redox potential of the Eu 3+|Eu 2+ couple, the Eu 2+ and Eu 3+ species coexist. Quantitative analysis of Eu 2+ and Eu 3+ was performed by spectrophotometry and by potentiometry. Under the coexistence of Eu 2+ and Eu 3+, potentiometric titration of Eu ion using a yttria-stabilized zirconia membrane electrode (YSZME) was performed by changing the concentration of O 2-. The formation of the europium oxychloride, EuOCl, was confirmed by X-ray diffraction analysis, whiles no precipitation of the oxides, EuO and Eu 2O 3, was found. The equivalent point of the EuOCl formation ( x = [O 2-] added/[Eu] total) was shifted to a smaller value from the theoretical value ( x = 1) due to the coexisting Eu 2+. The contribution of the coexisting Eu 2+ to the formation of EuOCl was estimated by using [Eu 2+]/[Eu 3+] as determined by potentiometry and this was subtracted from the titration data. The solubility product of EuOCl was determined to be p ks(EuOCl) = 7.81 ± 0.10.

  12. LaVo4: Eu Phosphor Films with Enhanced Eu Solubility

    SciTech Connect

    Hwang, Harold

    2011-08-11

    Eu doped rare-earth orthovanadates are known to be good red phosphor materials. In particular, LaVO{sub 4}:Eu is a promising candidate due to the low Eu-site point symmetry, and thus high dipole transition probability within Judd-Ofelt theory. However, the low solubility limit (< 3 mol %) of Eu in LaVO{sub 4} prevents its efficient use as a phosphor. We present optical evidence of enhanced Eu solubility as high as 10 mol % in LaVO{sub 4}:Eu thin films grown by pulsed laser deposition and postannealing. The photoluminescent intensity exceeded that of YVO{sub 4}:Eu thin films when excited below the host bandgap, indicating stronger direct emission of Eu in LaVO{sub 4}.

  13. Tuning Mixed-Valent Eu(2+) /Eu(3+) in Strontium Formate Frameworks for Multichannel Photoluminescence.

    PubMed

    Liu, Wei; Liu, Lijia; Wang, Yanlong; Chen, Lanhua; McLeod, John A; Yang, Linju; Zhao, Jia; Liu, Zhiyong; Diwu, Juan; Chai, Zhifang; Albrecht-Schmitt, Thomas E; Liu, Guokui; Wang, Shuao

    2016-08-01

    Cooperative performance of mixed-valent Eu(2+) /Eu(3+) in single-compound phosphors offers significant advantages in color rendering and luminescence efficiency, but their synthesis is challenging because of Eu(2+) oxidation. Using the tunable nature of the metal-ion nodes in metal-organic frameworks (MOFs), we present an in situ reduction and crystallization route for preparing MOFs and doping Eu(2+) /Eu(3+) with a controlled ratio. These materials exhibit rich photoluminescence, including intrinsic- and sensitized-emissions of Eu(2+) and Eu(3+) , and long-lived luminescence from charge transfer. Color rendering can be easily achieved by fine-tuning the valence states of Eu. A linear relation between temperature and the intensity ratio of Eu(2+) /Eu(3+) emissions provides outstanding properties for applications as self-calibrated luminescent thermometers with a wide working temperature range. Further incorporation of Tb(3+) into the MOFs results in white light, utilizing all Eu(2+) ,Tb(3+) , and Eu(3+) emissions in a single crystalline lattice. PMID:27305606

  14. Study of Eu{sup 3+} → Eu{sup 2+} reduction in BaAl{sub 2}O{sub 4}:Eu prepared in different gas atmospheres

    SciTech Connect

    Rezende, Marcos V. dos S.; Valerio, Mário E.G.; Jackson, Robert A.

    2015-01-15

    Highlights: • The effect of different gas atmospheres on the Eu reduction process was studied. • The Eu reduction was monitored analyzing XANES region at the Eu L{sub III}-edge. • Hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization. • Only a part of the Eu ions can be stabilized in the divalent state. • A model of Eu reduction process is proposed. - Abstract: The effect of different gas atmospheres such as H{sub 2}(g), synthetic air, carbon monoxide (CO) and nitrogen (N{sub 2}) on the Eu{sup 3+} → Eu{sup 2+} reduction process during the synthesis of Eu-doped BaAl{sub 2}O{sub 4} was studied using synchrotron radiation. The Eu{sup 3+} → Eu{sup 2+} reduction was monitored analyzing XANES region when the sample are excited at the Eu L{sub III}-edge. The results show that the hydrogen reducing agent are the most appropriate gas for Eu{sup 2+} stabilization in BaAl{sub 2}O{sub 4} and that only a part of the Eu ions can be stabilized in the divalent state. A model of Eu reduction process, based on the incorporation of charge compensation defects, is proposed.

  15. Magnetic and Fermi Surface Properties of Ferromagnets EuPd2 and EuPt2

    NASA Astrophysics Data System (ADS)

    Nakamura, Ai; Akamine, Hiromu; Ashitomi, Yousuke; Honda, Fuminori; Aoki, Dai; Takeuchi, Tetsuya; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Tatetsu, Yasutomi; Maehira, Takahiro; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

    2016-08-01

    We succeeded in growing single crystals of the ferromagnets EuPd2 and EuPt2 with the Laves-type cubic structure by the Bridgman method, namely, heating constituting materials in a Mo crucible up to a high temperature of about 1500 °C. The ferromagnetic properties of EuPd2 and EuPt2 with Curie temperatures of 74 and 100 K, respectively, were confirmed from the results of electrical resistivity, specific heat, and magnetization measurements. The ordered moment is 7 μB/Eu, revealing the Eu-divalent ferromagnetism. The present Eu-divalent electronic state is found to be robust against high pressures of up to 8 GPa and is not changed into the Eu-trivalent state. We also carried out de Haas-van Alphen (dHvA) experiments for EuPd2. The detected dHvA branches in EuPd2 are well explained by the relativistic linearized augmented plane wave (RLAPW) energy band calculations for SrPd2, revealing a closed hole Fermi surface and compensated four closed electron Fermi surfaces.

  16. Emerging food safety issues: An EU perspective.

    PubMed

    McEvoy, John D G

    2016-05-01

    Safe food is the right of every citizen of the European Union (EU). A comprehensive and dynamic framework of food and feed safety legislation has been put in place and the EU's executive arm - the European Commission - is responsible for ensuring that the EU member states apply food law consistently. Similarly, the Commission plays an important role in ensuring that imported food meets the EU's stringent food safety standards. Consumer perceptions of unsafe food tend to focus on acute outbreaks of bacterial or viral origin. In recent years there have been a number of diverse food crises associated with fraudulent activity which may (e.g. melamine in dairy products in China) or may not (e.g. the horse meat scandal in the EU) represent a genuine food safety risk. Well publicized incidents of chronic exposure to chemical contamination in the EU (e.g. dioxins in meat and mycotoxins in nuts) have required robust coordinated policy responses from the Commission. Despite the decreasing incidence of non-compliant residues of veterinary medicinal products and banned substances in animal products, EU consumers are increasingly concerned about the use of such products in food-producing animals, including in the context of the build-up of antimicrobial resistance in animals and transfer to humans. The Commission plays a key role in coordination of the EU member states' responses to such incidents, in risk management, and in preparation for emerging issues. This paper focuses on how the EU as a whole has dealt with a number of food crises, and what can be learned from past incidents. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27443205

  17. Chimeric 2C10R4 anti-CD40 antibody therapy is critical for long-term survival of GTKO.hCD46.hTBM pig-to-primate cardiac xenograft

    PubMed Central

    Mohiuddin, Muhammad M.; Singh, Avneesh K.; Corcoran, Philip C.; Thomas III, Marvin L.; Clark, Tannia; Lewis, Billeta G.; Hoyt, Robert F.; Eckhaus, Michael; Pierson III, Richard N.; Belli, Aaron J.; Wolf, Eckhard; Klymiuk, Nikolai; Phelps, Carol; Reimann, Keith A.; Ayares, David; Horvath, Keith A.

    2016-01-01

    Preventing xenograft rejection is one of the greatest challenges of transplantation medicine. Here, we describe a reproducible, long-term survival of cardiac xenografts from alpha 1-3 galactosyltransferase gene knockout pigs, which express human complement regulatory protein CD46 and human thrombomodulin (GTKO.hCD46.hTBM), that were transplanted into baboons. Our immunomodulatory drug regimen includes induction with anti-thymocyte globulin and αCD20 antibody, followed by maintenance with mycophenolate mofetil and an intensively dosed αCD40 (2C10R4) antibody. Median (298 days) and longest (945 days) graft survival in five consecutive recipients using this regimen is significantly prolonged over our recently established survival benchmarks (180 and 500 days, respectively). Remarkably, the reduction of αCD40 antibody dose on day 100 or after 1 year resulted in recrudescence of anti-pig antibody and graft failure. In conclusion, genetic modifications (GTKO.hCD46.hTBM) combined with the treatment regimen tested here consistently prevent humoral rejection and systemic coagulation pathway dysregulation, sustaining long-term cardiac xenograft survival beyond 900 days. PMID:27045379

  18. Variability of Phenology and Fluxes of Water and Carbon with Observed and Simulated Soil Moisture in the Ent Terrestrial Biosphere Model (Ent TBM Version 1.0.1.0.0)

    NASA Technical Reports Server (NTRS)

    Kim, Y.; Moorcroft, P. R.; Aleinov, Igor; Puma, M. J.; Kiang, N. Y.

    2015-01-01

    The Ent Terrestrial Biosphere Model (Ent TBM) is a mixed-canopy dynamic global vegetation model developed specifically for coupling with land surface hydrology and general circulation models (GCMs). This study describes the leaf phenology submodel implemented in the Ent TBM version 1.0.1.0.0 coupled to the carbon allocation scheme of the Ecosystem Demography (ED) model. The phenology submodel adopts a combination of responses to temperature (growing degree days and frost hardening), soil moisture (linearity of stress with relative saturation) and radiation (light length). Growth of leaves, sapwood, fine roots, stem wood and coarse roots is updated on a daily basis. We evaluate the performance in reproducing observed leaf seasonal growth as well as water and carbon fluxes for four plant functional types at five Fluxnet sites, with both observed and prognostic hydrology, and observed and prognostic seasonal leaf area index. The phenology submodel is able to capture the timing and magnitude of leaf-out and senescence for temperate broadleaf deciduous forest (Harvard Forest and Morgan- Monroe State Forest, US), C3 annual grassland (Vaira Ranch, US) and California oak savanna (Tonzi Ranch, US). For evergreen needleleaf forest (Hyytiäla, Finland), the phenology submodel captures the effect of frost hardening of photosynthetic capacity on seasonal fluxes and leaf area. We address the importance of customizing parameter sets of vegetation soil moisture stress response to the particular land surface hydrology scheme. We identify model deficiencies that reveal important dynamics and parameter needs.

  19. Chimeric 2C10R4 anti-CD40 antibody therapy is critical for long-term survival of GTKO.hCD46.hTBM pig-to-primate cardiac xenograft.

    PubMed

    Mohiuddin, Muhammad M; Singh, Avneesh K; Corcoran, Philip C; Thomas, Marvin L; Clark, Tannia; Lewis, Billeta G; Hoyt, Robert F; Eckhaus, Michael; Pierson, Richard N; Belli, Aaron J; Wolf, Eckhard; Klymiuk, Nikolai; Phelps, Carol; Reimann, Keith A; Ayares, David; Horvath, Keith A

    2016-01-01

    Preventing xenograft rejection is one of the greatest challenges of transplantation medicine. Here, we describe a reproducible, long-term survival of cardiac xenografts from alpha 1-3 galactosyltransferase gene knockout pigs, which express human complement regulatory protein CD46 and human thrombomodulin (GTKO.hCD46.hTBM), that were transplanted into baboons. Our immunomodulatory drug regimen includes induction with anti-thymocyte globulin and αCD20 antibody, followed by maintenance with mycophenolate mofetil and an intensively dosed αCD40 (2C10R4) antibody. Median (298 days) and longest (945 days) graft survival in five consecutive recipients using this regimen is significantly prolonged over our recently established survival benchmarks (180 and 500 days, respectively). Remarkably, the reduction of αCD40 antibody dose on day 100 or after 1 year resulted in recrudescence of anti-pig antibody and graft failure. In conclusion, genetic modifications (GTKO.hCD46.hTBM) combined with the treatment regimen tested here consistently prevent humoral rejection and systemic coagulation pathway dysregulation, sustaining long-term cardiac xenograft survival beyond 900 days. PMID:27045379

  20. Variability of phenology and fluxes of water and carbon with observed and simulated soil moisture in the Ent Terrestrial Biosphere Model (Ent TBM version 1.0.1.0.0)

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Moorcroft, P. R.; Aleinov, I.; Puma, M. J.; Kiang, N. Y.

    2015-12-01

    The Ent Terrestrial Biosphere Model (Ent TBM) is a mixed-canopy dynamic global vegetation model developed specifically for coupling with land surface hydrology and general circulation models (GCMs). This study describes the leaf phenology submodel implemented in the Ent TBM version 1.0.1.0.0 coupled to the carbon allocation scheme of the Ecosystem Demography (ED) model. The phenology submodel adopts a combination of responses to temperature (growing degree days and frost hardening), soil moisture (linearity of stress with relative saturation) and radiation (light length). Growth of leaves, sapwood, fine roots, stem wood and coarse roots is updated on a daily basis. We evaluate the performance in reproducing observed leaf seasonal growth as well as water and carbon fluxes for four plant functional types at five Fluxnet sites, with both observed and prognostic hydrology, and observed and prognostic seasonal leaf area index. The phenology submodel is able to capture the timing and magnitude of leaf-out and senescence for temperate broadleaf deciduous forest (Harvard Forest and Morgan-Monroe State Forest, US), C3 annual grassland (Vaira Ranch, US) and California oak savanna (Tonzi Ranch, US). For evergreen needleleaf forest (Hyytiäla, Finland), the phenology submodel captures the effect of frost hardening of photosynthetic capacity on seasonal fluxes and leaf area. We address the importance of customizing parameter sets of vegetation soil moisture stress response to the particular land surface hydrology scheme. We identify model deficiencies that reveal important dynamics and parameter needs.

  1. Synthesis and tunable luminescent properties of Eu-doped Ca2NaSiO4F - Coexistence of the Eu2+ and Eu3+ centers

    NASA Astrophysics Data System (ADS)

    Xie, Mubiao; Li, Dongyu; Zhu, Guoxian; Pan, Rongkai; Fu, Xionghui

    Novel phosphors Ca2NaSiO4F:Eu were synthesized successfully by the conventional solid-state method in CO atmosphere, and their spectroscopic properties in UV-vis region were investigated. The photoluminescence properties show that Eu3+ ions were partially reduced to Eu2+ in Ca2NaSiO4F. As a result of radiation and re-absorption energy transfer from Eu2+ to Eu3+, both Eu2+ bluish-green emission at around 520 nm and Eu3+ red emission are observed in the emission spectra under the n-UV light excitation. Furthermore, the ratio between Eu2+ and Eu3+ emissions varies with increasing content of overall Eu. Because relative intensity of the red component from Eu3+ became systematically stronger, white light emission can be realized by combining the emission of Eu2+ and Eu3+ in a single host lattice under n-UV light excitation. These results indicate that the Ca2NaSiO4F:Eu phosphors have potential applications as a n-UV convertible phosphor for light-emitting diodes.

  2. Antiferromagnetism in EuNiGe3

    SciTech Connect

    Goetsch, R. J.; Ananad, V. K.; Johnston, David C.

    2013-02-07

    The synthesis and crystallographic and physical properties of polycrystalline EuNiGe3 are reported. EuNiGe3 crystallizes in the noncentrosymmetric body-centered tetragonal BaNiSn3-type structure (space group I4mm), in agreement with previous reports, with the Eu atoms at the corners and body center of the unit cell. The physical property data consistently demonstrate that this is a metallic system in which Eu spins S = 7/2 order antiferromagnetically at a temperature TN = 13.6 K.Magnetic susceptibility χ data forT >TN indicate that the Eu atoms have spin 7/2 with g = 2, that the Ni atoms are nonmagnetic, and that the dominant interactions between the Eu spins are ferromagnetic. Thus we propose that EuNiGe3 has a collinear A-type antiferromagnetic structure, with the Eu ordered moments in the ab plane aligned ferromagnetically and with the moments in adjacent planes along the c axis aligned antiferromagnetically. A fit of χ(T TN) by our molecular field theory is consistent with a collinear magnetic structure. Electrical resistivity ρ data from TN to 350 K are fitted by the Bloch-Gr¨uneisen model for electron-phonon scattering, yielding a Debye temperature of 265(2) K.Astrong decrease in ρ occurs belowTN due to loss of spin-disorder scattering. Heat capacity data at 25 K T 300Kare fitted by the Debye model, yielding the same Debye temperature 268(2) K as found from ρ(T ). The extracted magnetic heat capacity is consistent with S = 7/2 and shows that significant short-range dynamical spin correlations occur above TN. The magnetic entropy at TN = 13.6 K is 83% of the expected asymptotic high-T value, with the remainder recovered by 30 K.

  3. Perceived Distributive Fairness of EU Transfer Payments, Outcome Favorability, Identity, and EU-Tax Compliance.

    PubMed

    Hartner, Martina; Rechberger, Silvia; Kirchler, Erich; Wenzel, Michael

    2011-01-01

    In a representative UK study (N = 1000) the link between distributive fairness perceptions, outcome favorability, identity, and tax compliance was researched in the context of European transfer payments. Results showed that both forms of tax compliance (i.e., individual and collective EU-tax compliance) were influenced by perceived distributive fairness judgments of EU transfer payments. Fairness itself was related to perceived outcome favorability (i.e., whether their own nation benefits from the EU in financial as well as socio-political terms). Additionally, national identifiers (i.e., people identifying with their own nation, but not with Europe) perceived EU membership as unbeneficial in financial as well as in socio-political terms and thus considered the transfer payments as less fair. Dual identifiers (i.e., people identifying with their own nation and with Europe) perceived the socio-political outcomes from EU membership as more beneficial and thus evaluated the transfer payments as fairer. PMID:21412442

  4. Do supranational EU institutions make a difference? EU asylum law before and after ‘communitarization’

    PubMed Central

    Ripoll Servent, Ariadna; Trauner, Florian

    2014-01-01

    ABSTRACT This article examines whether the empowerment of the European Union's (EU) supranational institutions has had an impact on the development of EU asylum. By systematically investigating EU asylum law before and after ‘communitarization’, it argues that its ‘policy core’ has maintained a high degree of continuity. An advocacy coalition under the leadership of the interior ministers managed to co-opt pivotal actors in the newly empowered European Commission and European Parliament. By contenting themselves with changes of secondary order, these EU institutions accepted and institutionalized the restrictive and weakly integrated core of EU asylum set by the Council in the first negotiation round. Their role and decisions were driven not only by the negotiation dynamics and political expediency, but also by new inter- and intra-institutional norms fostering consensual practices. PMID:26924934

  5. Effects of Eu concentration control on crystal growth and scintillation properties for Eu:LiSrAlF6 crystals

    NASA Astrophysics Data System (ADS)

    Suzuki, S.; Yokota, Y.; Yamaji, A.; Kurosawa, S.; Kamada, K.; Yoshikawa, A.

    2014-10-01

    Eu doped LiSrAlF6 (Eu:LiSAF) crystals with various Eu concentrations were grown by a micro-pulling-down (μ-PD) method and the effects of Eu concentration control on crystal growth and scintillation properties for Eu:LiSAF crystals were investigated as a neutron scintillator. As-grown Eu0.3%:LiSAF crystal had no visible inclusion while milky parts were observed in the crystals with higher Eu contents. The secondary phases with the chemical composition of EuF2 or EuF3 in the Eu:LiSAF matrix were observed for the crystals with high Eu contents while the secondary phase couldn’t be observed in the powder XRD patterns. In the radioluminescence spectra of Eu:LiSAF crystals under α-ray irradiation, emission peaks around 375 nm originated from 5d-4f transition of Eu2+ ion were observed. The light yields systematically increased with an increase of actual Eu contents in the crystals and the decay times were 1490-1620 ns.

  6. Eu Anomalies Constrain Recycling of Lower Continental Crust

    NASA Astrophysics Data System (ADS)

    Tang, M.; Rudnick, R. L.; McDonough, W. F.; Gaschnig, R. M.; Huang, Y.

    2014-12-01

    Europium is fractionated from Sm and Gd during intra-crustal differentiation since Eu (II) strongly partitions into feldspar. Statistical analysis of Sm-Eu-Gd concentrations in over 2000 samples from the continental crust reveal that the bulk continental crust has a negative Eu anomaly. Samples include (1) shales, loess, and tillites which represent upper continental crust (n = 415); (2) amphibolite facies rocks, which represent the middle continental crust (n = 1325) and (3) granulite facies rocks (n = 845), which represent the lower continental crust. The upper and middle continental crust have a significant negative Eu anomaly, while the lower continental crust has a significant positive Eu anomaly. The Eu deficit in the upper and middle continental crust, however, cannot be compensated by the Eu excess in the lower continental crust, leaving the bulk continental crust with a negative Eu anomaly (Eu/Eu* = 0.81 ± 0.04, 95% conf.). Since the building blocks of the continental crust (mantle-derived basalts or tonalitic slab melts) do not possess a negative Eu anomaly, removal of lower continental crust, which is the only crustal reservoir enriched in Eu, is required during crustal evolution. A mass balance model of the continents, based on Sm-Eu-Gd systematics, indicates that at least 2.2-3.0 crustal masses may have been added back to the mantle over Earth history via lower crustal recycling.

  7. What does Brexit mean for nursing and our EU staff?

    PubMed

    Flynn, Hannah; Kendall-Raynor, Petra; Longhurst, Chris

    2016-06-29

    Currently there is free movement of labour and mutual recognition of nurse training and qualifications between EU member states. This means UK hospitals can actively recruit nurses from across the EU to cover staff shortfalls. So what now? PMID:27353905

  8. The EU Dimension to Soil Science in Schools

    ERIC Educational Resources Information Center

    Johnson, Sue

    2012-01-01

    The EU as a context for science lessons may be given scant attention but EU decision-making is a vital factor in everyday life. Lessons on the emergence of soil science with Charles Darwin's simple scientific experiments can be linked with competence through action, inclusion and argumentations in science lessons. Decisions about an EU Soil…

  9. {sup 151}Eu and {sup 121}Sb Moessbauer spectroscopy of EuSbSe{sub 3} and EuBiSe{sub 3}

    SciTech Connect

    Schappacher, Falko M.; Poettgen, Rainer Bang Jin, Geng; Albrecht-Schmitt, Thomas E.

    2007-11-15

    {sup 151}Eu and {sup 121}Sb Moessbauer spectroscopy of EuSbSe{sub 3} and EuBiSe{sub 3} were measured at different temperatures. The presence of divalent europium and trivalent antimony were confirmed. The largely negative values of the isomer shift in {sup 151}Eu spectrum show highly ionic bonding within these two compounds. Both of them show magnetic hyperfine field splitting at 4.2 K, which indicates a change in the orientation of the EFG principal axis with respect to the magnetic hyperfine field direction. EuSbSe{sub 3} has slightly smaller electron density at the antimony nuclei, compared to Sb{sub 2}Se{sub 3.} - Graphical abstract: Experimental and simulated {sup 121}Sb Moessbauer spectrum of EuSbSe{sub 3} at 77 K.

  10. Effect of Eu-citrate complex composition on its cementation

    SciTech Connect

    Lebedev, V.M.; Kornilov, A.S.; Yadovin, A.A.

    1995-03-01

    The dependence of Eu cementation by sodium amalgam in a semicountercurrent regime from citrate solutions on the Eu complex composition is studied. The purity of the {sup 153}Gd product from radioactive Eu can be increased during cementation by introducing correcting solutions of citric acid and stable Eu. The selected conditions are verified by processing irradiated targets. The content of radioactive Eu in the {sup 153}Gd product is reduced from 0.01 to 0.0005% with respect to {gamma}-activity.

  11. Get Acquainted With EU Safety Glove Standards.

    PubMed

    Courtney, Simon

    2016-02-01

    As with many of the standards developed as a result of the EU Directive on PPE, the classification of a glove in a particular test is usually defined as one of a series of performance levels (usually between 1 and 4 or 5). It is then left to the user, following a suitable risk assessment exercise, to select a glove with a suitable profile of performance levels in relevant tests. PMID:26983326

  12. On the Luminescence Enhancement of Mn2+ By Co-doping of Eu2+ in ZnS:Mn,Eu

    SciTech Connect

    Hossu, Marius; Schaeffer, Roger O.; Ma, Lun; Chen, Wei; Zhu, Yongbin; Sammynaiken, Ramaswami; Joly, Alan G.

    2013-06-01

    The photoluminescence and X-ray luminescence of ZnS:Mn, ZnS:Mn,Eu and ZnS:Eu were investigated and it was found that the luminescence intensity of Mn2+ in ZnS:Mn,Eu co-doped phosphors is highly dependent on the doping concentration of Eu2+. At the optimized Eu2+concentration (0.2%), the photoluminescence of Mn2+ shows about a 5.5 times enhancement and its X-ray luminescence is enhanced by a factor of 2.5. Both wurtzite and zinc blend phases are present in the samples with wurtzite phase dominant. Co-doping of Eu2+ into ZnS:Mn does not change appreciably the ratio of the two phases or the Mn2+ emission luminescence lifetime; however, the doping of Eu2+ into ZnS:Mn does change the phonon activity. Furthermore, it was found that the defect-related blue emission of ZnS:Eu overlaps with the excitation bands of Mn2+ in ZnS:Mn and there is likely energy transfer from these defect states to Mn2+ in ZnS:Mn,Eu. This energy transfer and the phonon modification are considered to be the two main reasons for the luminescence enhancement and the intensity dependence of Mn2+ emission on Eu2+ doping concentration in ZnS:Mn,Eu.

  13. Contribution of Eu ions on the precipitation of silver nanoparticles in Ag-Eu co-doped borate glasses

    SciTech Connect

    Jiao, Qing; Qiu, Jianbei; Zhou, Dacheng; Xu, Xuhui

    2014-03-01

    Graphical abstract: - Highlights: • Silver nanoparticles are precipitated from the borate glasses during the melting process without any further heat treatment. • The reduction of Eu{sup 3+} ions to Eu{sup 2+} ions is presented in this material. • The intensity of Ag{sup +} luminescence. • The introduction of Eu ions accelerated the reaction between Eu{sup 2+} ions and silver ions inducing the silver clusters formation. - Abstract: Ag{sup +} doped sodium borate glasses with different Eu ions concentration were prepared by the melt-quenching method. The absorption at about 410 nm which was caused by the surface plasmon resonance (SPR) of Ag nanoparticles (NPs) is promoted with increasing of Eu ions concentration. Meanwhile, the luminescent spectra showed that the emission intensity of Ag{sup +} decreased while that of the Ag aggregates increased simultaneously. The results indicated that the Ag ions intend to form the high-polymeric state such as Ag aggregates and nanoparticles with increasing of europium ions. Owing to the self-reduction of Eu{sup 3+} to Eu{sup 2+} in our glass system, it revealed that Ag{sup +} has been reduced by the neighboring Eu{sup 2+} which leads to the formation of Ag aggregates and the precipitation of Ag NPs in the matrix. In addition, energy transfer (ET) process from Ag{sup +}/Ag aggregates to the Eu{sup 3+} was investigated for the enhancement of Eu{sup 3+} luminescence.

  14. Framing the EU as Common Project vs. Common Heritage: Effects on Attitudes Towards the EU Deepening and Widening.

    PubMed

    La Barbera, Francesco

    2015-01-01

    The present study investigated the effects of framing the European Union (EU) as a common project vs. a common heritage on participants' attitude towards EU integration (Experiment 1) and EU enlargement (Experiment 2). An additional aim was exploring whether the different frames affected the strength of identification with the EU, and if the framing effect on attitudes was mediated by participants' identification with the EU and/or by their message evaluation (Experiment 3). Results showed that a common project-based frame was more effective than a common heritage-based frame in promoting positive attitude toward EU integration and enlargement, as well as participants' identification with the EU, which mediated the framing effect on both attitudes; the mediation of participants' message evaluation was not significant. The procedure of the last experiment was replicated on a British sample (Experiment 4), showing a similar pattern of results. PMID:25898068

  15. Induced spin-polarization of EuS at room temperature in Ni/EuS multilayers

    SciTech Connect

    Poulopoulos, P.; Goschew, A.; Straub, A.; Fumagalli, P.; Kapaklis, V.; Wolff, M.; Delimitis, A.; Wilhelm, F.; Rogalev, A.; Pappas, S. D.

    2014-03-17

    Ni/EuS multilayers with excellent multilayer sequencing are deposited via e-beam evaporation on the native oxide of Si(100) wafers at 4 × 10{sup −9} millibars. The samples have very small surface and interface roughness and show sharp interfaces. Ni layers are nanocrystalline 4–8 nm thick and EuS layers are 2–4 nm thick and are either amorphous or nanocrystalline. Unlike for Co/EuS multilayers, all Eu ions are in divalent (ferromagnetic) state. We show a direct antiferromagnetic coupling between EuS and Ni layers. At room temperature, the EuS layers are spin-polarized due to the proximity of Ni. Therefore, Ni/EuS is a candidate for room-temperature spintronics applications.

  16. Measurement and analysis of the muonic x rays of 151Eu and 153Eu

    NASA Astrophysics Data System (ADS)

    Tanaka, Y.; Steffen, R. M.; Shera, E. B.; Reuter, W.; Hoehn, M. V.; Zumbro, J. D.

    1984-05-01

    Monopole and quadrupole charge distributions of 151Eu and 153Eu were investigated by muonic atom K and L x-ray measurements. The model-independent Barrett charge radii Rk and the isotope shift ΔRk were measured, and the value of Δ=0.606(18) fm2 was deduced. This isotope shift is the largest known of all nuclear pairs. The isomer shift of the first excited state of 153Eu is found to be close to zero, in contrast to the large isomer shifts observed in its neighbors: 152Sm and 154Gd. The quadrupole moments of the first excited states were determined as Q151(72+)=1.28(2) e b and Q153(72+)=0.44(2) e b. The value for 151Eu and its ground-state quadrupole moment of Q151(52+)=0.90(1) e b reported previously are several times larger than the respective single particle units. This fact shows that a fair amount of collectivity is involved in the 52+ ground state and in the 72+ first excited state of 151Eu.

  17. Definition of an intramolecular Eu-to-Eu energy transfer within a discrete [Eu2L] complex in solution.

    PubMed

    Nonat, Aline; Regueiro-Figueroa, Martín; Esteban-Gómez, David; de Blas, Andrés; Rodríguez-Blas, Teresa; Platas-Iglesias, Carlos; Charbonnière, Loïc J

    2012-06-25

    Ligand L, based on two do3a moieties linked by the methylene groups of 6,6'-dimethyl-2,2'-bipyridine, was synthesized and characterized. The addition of Ln salts to an aqueous solution of L (0.01 M Tris-HCl, pH 7.4) led to the successive formation of [LnL] and [Ln(2)L] complexes, as evidenced by UV/Vis and fluorescence titration experiments. Homodinuclear [Ln(2)L] complexes (Ln = Eu, Gd, Tb, Yb, and Lu) were prepared and characterized. The (1)H and (13)C NMR spectra of the Lu and Yb complexes in D(2)O solution (pD = 7.0) showed C(1) symmetry of these species in solution, pointing to two different chemical environments for the two lanthanide cations. The analysis of the chemical shifts of the Yb complex indicated that the two coordination sites present square antiprismatic (SAP) coordination environments around the metal ions. The spectroscopic properties of the [Tb(2)L] complex upon ligand excitation revealed conventional behavior with τ(H2O) = 2.05(1) ms and ϕ(H2O) = 51%, except for the calculation of the hydration number obtained from the luminescent lifetimes in H(2)O and D(2)O, which pointed to a non-integer value of 0.6 water molecules per Tb(III) ion. In contrast, the Eu complex revealed surprising features such as: 1) the presence of two and up to five components in the (5)D(0)→(7)F(0) and (5)D(0)→(7)F(1) emission bands, respectively; 2) marked differences between the normalized spectra obtained in H(2)O and D(2)O solutions; and 3) unconventional temporal evolution of the luminescence intensity at certain wavelengths, the intensity profile first displaying a rising step before the occurrence of the expected decay. Additional spectroscopic experiments performed on [Gd(2-x)Eu(x)L] complexes (x = 0.1 and 1.9) confirmed the presence of two distinct Eu sites with hydration numbers of 0 (site I) and 2 (site II), and showed that the unconventional temporal evolution of the emission intensity is the result of an unprecedented intramolecular Eu-to-Eu

  18. Controlled synthesis and novel photoluminescence properties of BaTiO{sub 3}:Eu{sup 3+}/Eu{sup 2+} nanocrystals

    SciTech Connect

    Feng, Li; Li, Ying; Wang, Guofeng Xu, Bingyu

    2015-01-15

    Highlights: • Tetragonal phase BaTiO{sub 3}:Eu nanocrystals were successfully synthesized using a hydrothermal method. • Under 398 nm excitation, the emissions from Eu{sup 2+} and Eu{sup 3+} ions were observed. • The emission band of Eu{sup 2+} from BaTiO{sub 3}:Eu was observed to broaden with increasing Eu concentration. - Abstract: Tetragonal phase BaTiO{sub 3}:Eu nanocrystals were successfully synthesized using a hydrothermal method and a subsequent calcination treatment. The structures and morphologies of nanocrystals were characterized by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and scanning electron microscopy. The photoluminescence properties of BaTiO{sub 3}:Eu were investigated in detail. Under 398 nm excitation, the emissions from Eu{sup 2+} and Eu{sup 3+} ions were observed, indicating that Eu{sup 2+} and Eu{sup 3+} ions coexisted in BaTiO{sub 3}:Eu nanocrystals. Especially, the emission band of Eu{sup 2+} from BaTiO{sub 3}:Eu was observed to broaden with increasing Eu concentration. When the Eu concentration was 0.5 mol%, the {sup 5}D{sub 0} → {sup 7}F{sub 0} and {sup 5}D{sub 1} → {sup 7}F{sub 0} emissions were observed. In addition, under 537 nm excitation, the emission intensity increased with increasing Eu concentration.

  19. Evidence of Eu{sup 2+} 4f electrons in the valence band spectra of EuTiO{sub 3} and EuZrO{sub 3}

    SciTech Connect

    Kolodiazhnyi, T.; Valant, M.; Williams, J. R.; Bugnet, M.; Botton, G. A.; Ohashi, N.; Sakka, Y.

    2012-10-15

    We report on optical band gap and valence electronic structure of two Eu{sup 2+}-based perovskites, EuTiO{sub 3} and EuZrO{sub 3} as revealed by diffuse optical scattering, electron energy loss spectroscopy, and valence-band x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence band structure is formed by the narrow Eu 4f{sup 7} electron band. The O 2p band shows the features similar to those of the Ba(Sr)TiO{sub 3} perovskites except that it is shifted to higher binding energies. Appearance of the Eu{sup 2+} 4f{sup 7} band is a reason for narrowing of the optical band gap in the title compounds as compared to their Sr-based analogues.

  20. [Influence of Eu2+ content on the spectral characteristics of BaMgAl10O17 : Eu2+ phosphors].

    PubMed

    Chen, Zhe; Xie, Hong; Yan, You-Wei

    2007-04-01

    Nanocrsytalline Ba(1-x)MgAl10O17 : xEu2+ (0.05 < or = x < or = 0.4) blue-emitting phosphor was successfully prepared by low-temperature combustion synthesis. The influence of different Eu content on the spectral characteristics of Ba(1-x) MgAl10O17 : xEu2+ was mainly investigated. The results of XRD and SEM analysis show that the sample is single phase and its average grain size is about 30 nm. The luminescence property of Ba(1-x)MgAl10O17 : xEu2+ phosphor is considerably influenced by Eu2+ concentration. In an appropriate Eu2+ doping concentration range, the intensity of the fluorescence of Ba(1-x)MgAl10O17 : xEu2+ was increased obviously with increasing the Eu2+ doping concentration, owing to adding the number of luminescent centers and enhancing the energy transfer between Eu2+ ions. The optimum emission intensity was reached at x = 0.2. However, as the Eu2+ doping concentration was higher than 0.2, the intensity of the fluorescence was reduced, due to the concentration quenching occurrence. PMID:17608168

  1. Controlled synthesis of Eu2+ and Eu3+ doped ZnS quantum dots and their photovoltaic and magnetic properties

    NASA Astrophysics Data System (ADS)

    Horoz, Sabit; Yakami, Baichhabi; Poudyal, Uma; Pikal, Jon M.; Wang, Wenyong; Tang, Jinke

    2016-04-01

    Eu-doped ZnS quantum dots (QDs) have been synthesized by wet-chemical method and found to form in zinc blende (cubic) structure. Both Eu2+ and Eu3+ doped ZnS can be controllably synthesized. The Eu2+ doped ZnS QDs show broad photoluminescence emission peak around 512 nm, which is from the Eu2+ intra-ion transition of 4f6d1 - 4f7, while the Eu3+ doped samples exhibit narrow emission lines characteristic of transitions between the 4f levels. The investigation of the magnetic properties shows that the Eu3+ doped samples exhibit signs of ferromagnetism, on the other hand, Eu2+ doped samples are paramagnetic of Curie-Weiss type. The incident photon to electron conversion efficiency is increased with the Eu doping, which suggests the QD solar cell efficiency can be enhanced by Eu doping due to widened absorption windows. This is an attractive approach to utilize benign and environmentally friendly wide band gap ZnS QDs in solar cell technology.

  2. Eu oxidation state in fluorozirconate-based glass ceramics

    SciTech Connect

    Henke, B.; Passlick, C.; Keil, P.; Johnson, J. A.; Schweizer, S.

    2009-12-01

    The influence of InF{sub 3} doping and remelting on Eu-doped fluorozirconate-based glass ceramics was investigated using near-edge x-ray absorption and optical spectroscopy. It was found that the addition of InF{sub 3} to the melt decreases the Eu{sup 2+}/Eu{sup 3+} mole ratio, while remelting leads to a significant change in the Eu{sup 2+}/Eu{sup 3+} ratio in favor of Eu{sup 2+}. Photoluminescence spectroscopy shows that additional annealing steps lead to the formation of BaCl{sub 2} nanoparticles in the glass. In as-made glass ceramics containing InF{sub 3}, a phase transition of the nanoparticles from hexagonal to orthorhombic structure is observed. This phase transition is not observed in the remelted glasses studied here.

  3. Luminescent nitridophosphates CaP2 N4 :Eu(2+) , SrP2 N4 :Eu(2+) , BaP2 N4 :Eu(2+) , and BaSr2 P6 N12 :Eu(2.).

    PubMed

    Pucher, Florian J; Marchuk, Alexey; Schmidt, Peter J; Wiechert, Detlef; Schnick, Wolfgang

    2015-04-20

    Nitridophosphates MP2 N4 :Eu(2+) (M=Ca, Sr, Ba) and BaSr2 P6 N12 :Eu(2+) have been synthesized at elevated pressures and 1100-1300 °C starting from the corresponding azides and P3 N5 with EuCl2 as dopant. Addition of NH4 Cl as mineralizer allowed for the growth of single crystals. This led to the successful structure elucidation of a highly condensed nitridophosphate from single-crystal X-ray diffraction data (CaP2 N4 :Eu(2+) (P63 , no. 173), a=16.847(2), c=7.8592(16) Å, V=1931.7(6) Å(3) , Z=24, 2033 observed reflections, 176 refined parameters, wR2 =0.096). Upon excitation by UV light, luminescence due to parity-allowed 4f(6) ((7) F)5d(1) →4f(7) ((8) S7/2 ) transition was observed in the orange (CaP2 N4 :Eu(2+) , λmax =575 nm), green (SrP2 N4 :Eu(2+) , λmax =529 nm), and blue regions of the visible spectrum (BaSr2 P6 N12 :Eu(2+) and BaP2 N4 :Eu(2+) , λmax =450 and 460 nm, respectively). Thus, the emission wavelength decreases with increasing ionic radius of the alkaline-earth ions. The corresponding full width at half maximum values (2240-2460 cm(-1) ) are comparable to those of other known Eu(2+) -doped (oxo)nitrides emitting in the same region of the visible spectrum. Following recently described quaternary Ba3 P5 N10 Br:Eu(2+) , this investigation represents the first report on the luminescence of Eu(2+) -doped ternary nitridophosphates. Similarly to nitridosilicates and related oxonitrides, Eu(2+) -doped nitridophosphates may have the potential to be further developed into efficient light-emitting diode phosphors. PMID:25765825

  4. The Structure of the EU Mediasphere

    PubMed Central

    Flaounas, Ilias; Turchi, Marco; Ali, Omar; Fyson, Nick; De Bie, Tijl; Mosdell, Nick; Lewis, Justin; Cristianini, Nello

    2010-01-01

    Background A trend towards automation of scientific research has recently resulted in what has been termed “data-driven inquiry” in various disciplines, including physics and biology. The automation of many tasks has been identified as a possible future also for the humanities and the social sciences, particularly in those disciplines concerned with the analysis of text, due to the recent availability of millions of books and news articles in digital format. In the social sciences, the analysis of news media is done largely by hand and in a hypothesis-driven fashion: the scholar needs to formulate a very specific assumption about the patterns that might be in the data, and then set out to verify if they are present or not. Methodology/Principal Findings In this study, we report what we think is the first large scale content-analysis of cross-linguistic text in the social sciences, by using various artificial intelligence techniques. We analyse 1.3 M news articles in 22 languages detecting a clear structure in the choice of stories covered by the various outlets. This is significantly affected by objective national, geographic, economic and cultural relations among outlets and countries, e.g., outlets from countries sharing strong economic ties are more likely to cover the same stories. We also show that the deviation from average content is significantly correlated with membership to the eurozone, as well as with the year of accession to the EU. Conclusions/Significance While independently making a multitude of small editorial decisions, the leading media of the 27 EU countries, over a period of six months, shaped the contents of the EU mediasphere in a way that reflects its deep geographic, economic and cultural relations. Detecting these subtle signals in a statistically rigorous way would be out of the reach of traditional methods. This analysis demonstrates the power of the available methods for significant automation of media content analysis. PMID

  5. Optical properties of Eu{sup 2+}/Eu{sup 3+} mixed valence, silicon nitride based materials

    SciTech Connect

    Kate, Otmar M. ten; Vranken, Thomas; Kolk, Erik van der; Jansen, Antonius P.J.; Hintzen, Hubertus T.

    2014-05-01

    Eu{sub 2}SiN{sub 3}, a mixed valence europium nitridosilicate, has been prepared via solid-state reaction synthesis and its oxidation behavior and optical properties have been determined. Furthermore, the stability of several isostructural compounds of the type M{sup 2+}L{sup 3+}SiN{sub 3} has been predicted by using the density functional theory calculations, and verified by the actual synthesis of CaLaSiN{sub 3}, CaEuSiN{sub 3} and EuLaSiN{sub 3}. The band gap of CaLaSiN{sub 3} was found around 3.2 eV giving the material its yellow color. Eu{sub 2}SiN{sub 3} on the other hand is black due to a combination of the 4f–5d absorption band of Eu{sup 2+} and the charge transfer band of Eu{sup 3+}. Thermogravimetric analysis and Raman spectroscopic study of Eu{sub 2}SiN{sub 3} revealed that oxidation of this compound in dry air takes place via a nitrogen retention complex. - Graphical abstract: Energy level scheme of Eu{sub 2}SiN{sub 3} showing the occupied N{sup 3−} 2p band (blue rectangle), unoccupied Eu{sup 2+} 5d band (white rectangle), occupied Eu{sup 2+} 4f ground states (filled red circles) and unoccupied Eu{sup 2+} ground states (open red circles). - Highlights: • Density functional theory calculations on the stability of M{sup 2+}L{sup 3+}SiN{sub 3} compounds. • Solid-state reaction synthesis of Eu{sub 2}SiN{sub 3}, CaLaSiN{sub 3}, EuLaSiN{sub 3} and CaEuSiN{sub 3}. • Determination of the Eu{sup 2+} 4f–5d and Eu{sup 3+} CT transitions in M{sup 2+}L{sup 3+}SiN{sub 3} compounds. • Oxidation of Eu{sub 2}SiN{sub 3} in dry air takes place via a nitrogen retention complex.

  6. Syntheses, crystal structures, and properties of EuRhIn, EuIr{sub 2}, and EuIrSn{sub 2}

    SciTech Connect

    Poettgen, R.; Hoffmann, R.D.; Moeller, M.H.; Kotzyba, G.; Kuennen, B.; Rosenhahn, C.; Mosel, B.D.

    1999-06-01

    The title compounds were prepared from the elements by reactions in sealed tantalum tubes in a high-frequency furnace. Their structures were refined from single crystal X-ray diffractometer data: Pnma, a = 744.4(1) pm, b = 434.15(9) pm, c = 845.5(1) pm, wR2 = 0.0433, 658 F{sup 2} values, 20 variables for EuRhIn, Rd3m, a = 756.5(1) pm, wR2 = 0.0349, 94 F{sup 2} values, 5 variables for EuIr{sub 2}, and Cmcm, a = 434.78(3) pm, b = 1124.0(1) pm, c = 751.20(5) pm, wR2 = 0.0561, 565 F{sup 2} values, 16 variables for EuIrSn{sub 2}. EuRhIn crystallizes with a TiNiSi type structure that consists of strongly puckered Rh{sub 3}In{sub 3} hexagons. The europium atoms fill the channels within the three-dimensional [RhIn] polyanion. EuRhIn orders ferromagnetically at 22.0(5) K with a saturation magnetic moment of 6.7(1) {mu}{sub B}/Eu at 4 k and 5.5 T. The divalent character of the europium atoms in EuRhIn was determined from temperature dependent susceptibility (7.9 {mu}{sub B}/Eu in the high-temperature part) and {sup 151}Eu Moessbauer spectroscopic experiments. The latter show an isomer shift of {delta} = {minus}8.30(2) mm/s at 78 K. At 4.2 K full magnetic hyperfine field splitting subjected to significant quadrupole splitting of {Delta}E{sub Q} = 8 mm/s is observed. EuRhIn is a metallic conductor with a room temperature value of 58 {micro}{Omega}cm for the specific resistivity. The structure of the Laves phase EuIr{sub 2} is confirmed on the basis of single crystal X-ray data. The iridium atoms form a tetrahedral network with Ir-Ir distances of 268 pm. EuIrSn{sub 2} adopts a MgCuAl{sub 2} type structure that may be described as an iridium-filled variant of a distorted CaIn{sub 2}-like sublattice of composition EuSn{sub 2}. The tin atoms in the distorted and puckered hexagonal network have shorter (303 and 322 pm) and longer (343 pm) tin-tin contacts. 40 refs., 9 figs., 5 tabs.

  7. The magnetic structure of EuCu2Sb2

    DOE PAGESBeta

    Ryan, D. H.; Cadogan, J. M.; Anand, V. K.; Johnston, D. C.; Flacau, R.

    2015-05-06

    Antiferromagnetic ordering of EuCu2Sb2 which forms in the tetragonal CaBe2Ge2-type structure (space group P4/nmm #129) has been studied using neutron powder diffraction and 151Eu Mössbauer spectroscopy. The room temperature 151Eu isomer shift of –12.8(1) mm/s shows the Eu to be divalent, while the 151Eu hyperfine magnetic field (Bhf) reaches 28.7(2) T at 2.1 K, indicating a full Eu2+ magnetic moment. Bhf(T) follows a smoothmore » $$S=\\frac{7}{2}$$ Brillouin function and yields an ordering temperature of 5.1(1) K. Refinement of the neutron diffraction data reveals a collinear A-type antiferromagnetic arrangement with the Eu moments perpendicular to the tetragonal c-axis. As a result, the refined Eu magnetic moment at 0.4 K is 7.08(15) μB which is the full free-ion moment expected for the Eu2+ ion with $$S=\\frac{7}{2}$$ and a spectroscopic splitting factor of g = 2.« less

  8. Exploring growth conditions and Eu2+ concentration effects for KSr2I5:Eu scintillator crystals

    NASA Astrophysics Data System (ADS)

    Stand, L.; Zhuravleva, M.; Camarda, G.; Lindsey, A.; Johnson, J.; Hobbs, C.; Melcher, C. L.

    2016-04-01

    Our current research is focused on understanding dopant optimization, growth rate, homogeneity and their impact on the overall performance of KSr2I5:Eu2+ single crystal scintillators. In this work we have investigated the effects of Eu2+ concentration in the potassium strontium iodide matrix, and we found that the concentration needed to maximize the light yield was 4 mol%. In order to assess the effects of the pulling rate, we grew single crystals at 12, 24 and 120 mm/day via the vertical Bridgman technique. For the sample sizes measured (5×5×5 mm3), we found that the crystal grown at the fastest rate of 120 mm/day showed a light yield within ~7% of the more slowly grown boules, and no significant change was observed in the energy resolution. Therefore, light yields from 88,000 to 96,000 ph/MeV and energy resolutions from 2.4 to 3.0% (at 662 keV) were measured for KSr2I5:Eu 4% over a relatively wide range of growth conditions. In order to assess the homogeneity of KSr2I5:Eu 4%, a newly developed micro-resolution X-ray technique was used to map the light yield as a function of excitation position. In the crystals that we studied, we did not observe any significant inhomogeneity other than a smooth gradient due to light collection and self absorption effects.

  9. Chemical bonding in EuTGe (T=Ni, Pd, Pt) and physical properties of EuPdGe

    SciTech Connect

    Rocquefelte, Xavier; Gautier, Regis; Halet, Jean-Francois Muellmann, Ralf; Rosenhahn, Carsten; Mosel, Bernd D.; Kotzyba, Gunter; Poettgen, Rainer

    2007-02-15

    EuPdGe was prepared from the elements by reaction in a sealed tantalum tube in a high-frequency furnace. Magnetic susceptibility measurements show Curie-Weiss behavior above 60 K with an experimental magnetic moment of 8.0(1){mu} {sub B}/Eu indicating divalent europium. At low external fields antiferromagnetic ordering is observed at T {sub N}=8.5(5) K. Magnetization measurements indicate a metamagnetic transition at a critical field of 1.5(2) T and a saturation magnetization of 6.4(1){mu} {sub B}/Eu at 5 K and 5.5 T. EuPdGe is a metallic conductor with a room-temperature value of 5000{+-}500 {mu}{omega} cm for the specific resistivity. {sup 151}Eu Moessbauer spectroscopic experiments show a single europium site with an isomer shift of {delta}=-9.7(1) mm/s at 78 K. At 4.2 K full magnetic hyperfine field splitting with a hyperfine field of B=20.7(5) T is observed. Density functional calculations show the similarity of the electronic structures of EuPdGe and EuPtGe. T-Ge interactions (T=Pd, Pt) exist in both compounds. An ionic formula splitting Eu{sup 2+} T {sup 0}Ge{sup 2-} seems more appropriate than Eu{sup 2+} T {sup 2+}Ge{sup 4-} accounting for the bonding in both compounds. Geometry optimizations of EuTGe (T=Ni, Pt, Pd) show weak energy differences between the two structural types. - Graphical abstract: Cutouts of the [PdGe] and [PtGe] polyanions in the structures of EuPdGe and EuPtGe. Atom designations and some relevant interatomic distances are given.

  10. Diabetes device reimbursement in the EU-5.

    PubMed

    Schäfer, Elmar; Schnell, Gerald; Bobáková, Tamara

    2013-07-01

    The reimbursement landscape for new and innovative diabetes devices in Europe is very heterogeneous and nontransparent, with each country employing different mechanisms, pathways, and requirements. This article provides an overview of how diabetes device reimbursement works in the outpatient setting in the five major European Union markets (France, Germany, Italy, Spain, and the United Kingdom; the EU-5). It will be of particular interest to manufacturers of innovative devices. Markets are first categorized as either a centralized or a regionalized reimbursement decision-making system, and implications for device reimbursement are explored. In the second part, specific requirements and success factors for wide reimbursement in the EU-5 are analyzed in detail. Gaining early acceptance by the main influencers (key opinion leaders and payers) is the first step. Equally important is the provision of convincing evidence, be this clinical, health-economic (cost-effectiveness), or a demonstration of cost savings (budget impact). In some countries, local usage data may be a requirement as well. Lastly, as payers' willingness to pay stems directly from their perceived value of a device, a key success factor and a necessary precondition for manufacturers is to set the right price. PMID:23911192

  11. Eu2+/Eu3+-doped oxyfluoride glass ceramics with LaF3 for white LED color conversion

    NASA Astrophysics Data System (ADS)

    Lee, Sang Hun; Bae, Suk-Rok; Choi, Yong Gyu; Chung, Woon Jin

    2015-03-01

    SiO2-Na2O-Al2O3-LaF3 glasses doped with Eu2+ and Eu3+ were synthesized to realize an inorganic color converter for white LED using 400 nm UV LED. Among various rare earth ions, Eu2+ and Eu3+ showed prominent emission under 400 nm LED excitation. Carbon and EuF3 content were varied to control the ratio of Eu2+ and Eu3+ during the melting process. When the ratio of Eu2+ and Eu3+ within the glass matrix was properly controlled, color coordinates of the photoluminescence spectra could be adjusted to make white colors under 400 nm LED excitation. The emission intensity was increased with subsequent heat treatment which led to the formation of LaF3 nano-crystals. However, almost no conversion was observed when the glasses were actually mounted on UV-LED to make a white LED. Heavy crystallization of the oxyfluoride glasses was thus investigated to improve its scattering of the light source and color conversion efficiency, and its practical feasibility as an inorganic UV-LED color converter was demonstrated.

  12. CsEuBr3: Crystal structure and its role in the photostimulation of CsBr :Eu2+

    NASA Astrophysics Data System (ADS)

    Hesse, S.; Zimmermann, J.; von Seggern, H.; Ehrenberg, H.; Fuess, H.; Fasel, C.; Riedel, R.

    2006-10-01

    CsBr :Eu2+ has recently been investigated as a photostimulable x-ray storage phosphor with great potential for application in high-resolution image plates. In a recent paper Hackenschmied et al. [J. Appl. Phys. 93, 5109 (2003)] suggested that segregations of CsEuBr3 or Cs4EuBr6 formed within CsBr :Eu2+ during annealing are responsible for an increase in the photostimulated luminescence (PSL) yield. In this work single crystals of CsEuBr3 were prepared by a one step synthesis and identified by x-ray diffraction (XRD) analysis as single phase perovskites. It was concluded that, after preparation, CsEuBr3 degrades in normal atmosphere into at least two phases, one of which is the orthorhombic structure of Cs2EuBr5•10H2O. The XRD powder diffraction pattern of this compound is very similar to that of the segregations observed within CsBr :Eu2+ and reported by Hackenschmied et al. However, the increased PSL yield in CsBr :Eu2+ after annealing cannot be due to the segregations, because the trivalent nature of the europium in the segregations renders them PSL inactive.

  13. An Assessment of EU 2020 Strategy: Too Far to Reach?

    ERIC Educational Resources Information Center

    Colak, Mehmet Selman; Ege, Aylin

    2013-01-01

    In 2010, EU adopted a new growth strategy which includes three growth priorities and five headline targets to be reached by 2020. The aim of this paper is to investigate the current performance of the EU member and candidate states in achieving these growth priorities and the overall strategy target by allocating the headline targets into the…

  14. EU-US ABWG AgENCODE Workshop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As considerable progress has been made on producing draft quality genomic sequence for many food animal species, the next goal for genomics research is a greater understanding of gene regulation and expression. The EU-US Animal Biotechnology Working Group (ABWG), established by the EU-US Biotechnolo...

  15. EuPathDB: a portal to eukaryotic pathogen databases.

    PubMed

    Aurrecoechea, Cristina; Brestelli, John; Brunk, Brian P; Fischer, Steve; Gajria, Bindu; Gao, Xin; Gingle, Alan; Grant, Greg; Harb, Omar S; Heiges, Mark; Innamorato, Frank; Iodice, John; Kissinger, Jessica C; Kraemer, Eileen T; Li, Wei; Miller, John A; Nayak, Vishal; Pennington, Cary; Pinney, Deborah F; Roos, David S; Ross, Chris; Srinivasamoorthy, Ganesh; Stoeckert, Christian J; Thibodeau, Ryan; Treatman, Charles; Wang, Haiming

    2010-01-01

    EuPathDB (http://EuPathDB.org; formerly ApiDB) is an integrated database covering the eukaryotic pathogens of the genera Cryptosporidium, Giardia, Leishmania, Neospora, Plasmodium, Toxoplasma, Trichomonas and Trypanosoma. While each of these groups is supported by a taxon-specific database built upon the same infrastructure, the EuPathDB portal offers an entry point to all these resources, and the opportunity to leverage orthology for searches across genera. The most recent release of EuPathDB includes updates and changes affecting data content, infrastructure and the user interface, improving data access and enhancing the user experience. EuPathDB currently supports more than 80 searches and the recently-implemented 'search strategy' system enables users to construct complex multi-step searches via a graphical interface. Search results are dynamically displayed as the strategy is constructed or modified, and can be downloaded, saved, revised, or shared with other database users. PMID:19914931

  16. Search for linking transitions in {sup 143}Eu

    SciTech Connect

    Lerma, F.; LaFosse, D.R.; Devlin, M.

    1996-12-31

    Six SD bands were populated in {sup 143}Eu and {sup 144}Eu, two of which had not been previously observed. Sum spectra were generated to search for two step links from the yrast SD band in {sup 143}Eu. However, no two step links were found. A single link from the SD band in {sup 143}Eu was found at 3364 keV. The level where it feeds into has not been identified. Alpha-particle energy (E{sub {alpha}}) spectra leading to the SD band and to normal states in {sup 143}Eu were measured and a correlation was found between E{sub {alpha}} and the level spin of the residual nucleus.

  17. [Effective laws for tobacco control: EU directives and Italian legislation].

    PubMed

    Charrier, Lorena; Piccinelli, Cristiano; Coppo, Alessandro; Di Stefano, Francesca; D'Elia, Paolo; Molinar, Roberta; Senore, Carlo; Giordano, Livia; Segnan, Nereo

    2006-01-01

    Effective tobacco control policies include law issuing: bans/restrictions on smoking in public areas and workplaces, increasing of taxes on tobacco products, bans on advertising of tobacco products, warning labels on cigarette boxes. For some of these policies the European Union (EU) has introduced specific directives that EU member states have to put into law. This paper briefly presents literature data, EU directives and the laws consequently issued in Italy. The importance of standardizing European legislation, especially for those policies that are not enforced by EU directives is also discussed. In Italy and in some other European countries smoking is forbidden in public and work-places, despite no EU directive. The positive impact of this ban in these countries suggests that it should be considered a priority in the European policies against tobacco in order to reduce the gap between literature recommendations and actions. PMID:17333695

  18. [Gd-doped natural thenardite: Eu photoluminescence properties of europium].

    PubMed

    Guzaliayi, Juman; Tuerxun, Aidilibike; Aizitiaili, Abulizi; Aierken, Sidike

    2012-06-01

    The authors prepared Na2SO4: Eu, Gd, and Na2Gd2 (SO4)4: Eu phosphors by heating, the mixed powder of GdF3, EuF3 and natural mirabilite with muffle furnace at 1 000 degrees C for 30 min and continually heating it with microwave at 750 degrees C for 10 min. With increasing the concentrations of Gd ion, the 610 nm emission intensity due to Eu3+ was strengthened. Gd3+ probably formed a bridge between substrate and the activator so that the energy is able to be transferred efficiently. The luminescence intensity, along with colorimetric purity, reaches the top with 21 mol% Gd3+ doping in the thenardite (Na2SO4: Eu) lattices, eventually coming up the quenching effects of concentration. PMID:22870627

  19. Low-lying electronic structure of EuH, EuOH, and EuO neutrals and anions determined by anion photoelectron spectroscopy and DFT calculations

    SciTech Connect

    Kafader, Jared O.; Ray, Manisha; Jarrold, Caroline Chick

    2015-07-21

    The anion photoelectron (PE) spectra of EuH{sup −} and the PE spectrum of overlapping EuOH{sup −} and EuO{sup −} anions are presented and analyzed with supporting results from density functional theory calculations on the various anions and neutrals. Results point to ionically bound, high-spin species. EuH and EuOH anions and neutrals exhibit analogous electronic structures: Transitions from {sup 8}Σ{sup −} anion ground states arising from the 4f{sup 7}σ{sub 6s}{sup 2} superconfiguration to the close-lying neutral {sup 9}Σ{sup −} and {sup 7}Σ{sup −} states arising from the 4f{sup 7}σ{sub 6s} superconfiguration are observed spaced by an energy interval similar to the free Eu{sup +} [4f{sup 7}6s] {sup 9}S - {sup 7}S splitting. The electron affinities (EAs) of EuH and EuOH are determined to be 0.771 ± 0.009 eV and 0.700 ± 0.011 eV, respectively. Analysis of spectroscopic features attributed to EuO{sup −} photodetachment is complicated by the likely presence of two energetically competitive electronic states of EuO{sup −} populating the ion beam. However, based on the calculated relative energies of the close-lying anion states arising from the 4f{sup 7}σ{sub 6s} and 4f{sup 6}σ{sub 6s}{sup 2} configurations and the relative energies of the one-electron accessible 4f{sup 7} and 4f{sup 6}σ{sub 6s} neutral states based on ligand-field theory [M. Dulick, E. Murad, and R. F. Barrow, J. Chem. Phys. 85, 385 (1986)], the remaining features are consistent with the 4f{sup 6}σ{sub 6s}{sup 2}  {sup 7}Σ{sup −} and 4f{sup 7}σ{sub 6s}{sup 7}Σ{sup −} anion states lying very close in energy (the former was calculated to be 0.15 eV lower in energy than the latter), though the true anion ground state and neutral EA could not be established unambiguously. Calculations on the various EuO anion and neutral states suggest 4f-orbital overlap with 2p orbitals in species with 4f{sup 6} occupancy.

  20. A Strategy to enhance Eu3+ emission from LiYF4:Eu nanophosphors and green-to-orange multicolor tunable, transparent nanophosphor-polymer composites

    PubMed Central

    Kim, Su Yeon; Won, Yu-Ho; Jang, Ho Seong

    2015-01-01

    LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu3+ emission from the nanophosphors are investigated. The optimized Eu3+ concentration is 35 mol%, and the red emission peaks due to the 5D0 →7FJ (J = 1 and 2) transitions of Eu3+ ions are further enhanced by energy transfer from a sensitizer pair of Ce3+ and Tb3+. The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu3+ emission than the core/shell strategies of LiYF4:Eu(35%)/LiYF4:Ce(15%), Tb(15%) and LiYF4:Ce(15%), Tb(15%)/LiYF4:Eu(35%) architectures. Efficient energy transfer from Ce3+ to Eu3+ through Tb3+ results in three times higher Eu3+ emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu3+ concentration. Owing to the energy transfer of Ce3+ → Tb3+ and Ce3+ → Tb3+ → Eu3+, intense green and red emission peaks are observed from LiYF4:Ce(13%), Tb(14%), Eu(1-5%) (LiYF4:Ce, Tb, Eu) nanophosphors, and the intensity ratio of green to red emission is controlled by adjusting the Eu3+ concentration. With increasing Eu3+ concentration, the LiYF4:Ce, Tb, Eu nanophosphors exhibit multicolor emission from green to orange. In addition, the successful incorporation of LiYF4:Ce, Tb, Eu nanophosphors into polydimethylsiloxane (PDMS) facilitates the preparation of highly transparent nanophosphor-PDMS composites that present excellent multicolor tunability. PMID:25597900

  1. Search for linking transitions in 143Eu

    NASA Astrophysics Data System (ADS)

    Lerma, F.; Lafosse, D. R.; Devlin, M.; Sarantites, D. G.; Asztalos, S.; Clark, R. M.; Fallon, P.; Lee, I. Y.; Macchiavelli, A. O.; MacLeod, R. W.; Baktash, C.; Brinkman, M. J.; Rudolph, D.

    1997-10-01

    An experiment was performed with the Gammasphere Ge-detector array, and the Microball charged particle detector, to search for transitions involved in the decay from the yrast superdeformed band in 143Eu. Sum spectra in coincidence with single, double, and triple gates on SD transitions were produced to search for previously reported two-step links between the superdeformed and the near-yrast ND levels. The sum spectra contained no evidence of peaks corresponding to sums of two-step linking transitions. Several discrete γ rays were observed in coincidence with the yrast SD band. One previously reported single-step transition at 3361 keV was confirmed to decay out of the SD band.

  2. Direct evidence for significant spin-polarization of EuS in Co/EuS multilayers at room temperature

    PubMed Central

    Pappas, S. D.; Poulopoulos, P.; Lewitz, B.; Straub, A.; Goschew, A.; Kapaklis, V.; Wilhelm, F.; Rogalev, A.; Fumagalli, P.

    2013-01-01

    The new era of spintronics promises the development of nanodevices, where the electron spin will be used to store information and charge currents will be replaced by spin currents. For this, ferromagnetic semiconductors at room temperature are needed. We report on significant room-temperature spin polarization of EuS in Co/EuS multilayers recorded by x-ray magnetic circular dichroism (XMCD). The films were found to contain a mixture of divalent and trivalent europium, but only Eu++ is responsible for the ferromagnetic behavior of EuS. The magnetic XMCD signal of Eu at room temperature could unambiguously be assigned to magnetic ordering of EuS and was found to be only one order of magnitude smaller than that at 2.5 K. The room temperature magnetic moment of EuS is as large as the one of bulk ferromagnetic Ni. Our findings pave the path for fabrication of room–temperature spintronic devices using spin polarized EuS layers. PMID:23434820

  3. Eu2+ and Eu3+ based "concentrated phosphors" as converters for UV LED light: two approaches and two new examples

    NASA Astrophysics Data System (ADS)

    Batentschuk, M.; Geisler, R.; Hum, J.; Iqbal, F.; Meister, F.; Osvet, A.; Stiegelschmitt, A.; Winnacker, A.

    2012-01-01

    The absolute majority of phosphors are composed of a host lattice and some percentage of an activator. At higher activator concentrations the concentration quenching occurs. However, there are phosphors in which only minor quenching of the emission occurs with increasing of the activator content. Based on the existence of two different valence states of the Eu ion (2+ and 3+), two approaches for the development of "concentrated phosphors", i.e. light emitting materials in which the activator ion is a main part of the crystal lattice, are discussed. In both approaches, reduced energy migration leading to the luminescence quenching is considered as a main condition to reach a high quantum efficiency of a concentrated phosphor. Two kinds of phosphors—Eu2+-doped alumosilicate and Eu3+-doped oxyfluoride—are used as an experimental basis for this discussion. Starting from the stoichiometric Ca_{1-x}Eux^{2+}Al2Si2O8 anorthite and Eu3+OF oxyfluorides, the non-stoichiometric powders with Eu^{2+}_{0.92}Al_{1.76}Si_{2.24}O8, Eu3+(O, F)2,35 and Eu3+(O, F)2,16 compositions were synthesized by a solid state reaction and investigated. It was shown that—in spite of the almost 100% Eu concentration—light converters with high quantum efficiency of more than 45% can be realized. A possible application of these materials as UV LED light converters for white light emitting diodes are discussed as well.

  4. Antiferromagnetism in EuCu2As2 and EuCu1.82Sb2 single crystals

    DOE PAGESBeta

    Anand, V. K.; Johnston, D. C.

    2015-05-07

    Single crystals of EuCu2As2 and EuCu2Sb2 were grown from CuAs and CuSb self-flux, respectively. The crystallographic, magnetic, thermal, and electronic transport properties of the single crystals were investigated by room-temperature x-ray diffraction (XRD), magnetic susceptibility χ versus temperature T, isothermal magnetization M versus magnetic field H, specific heat Cp(T), and electrical resistivity ρ(T) measurements. EuCu2As2 crystallizes in the body-centered tetragonal ThCr2Si2-type structure (space group I4/mmm), whereas EuCu2Sb2 crystallizes in the related primitive tetragonal CaBe2Ge2-type structure (space group P4/nmm). The energy-dispersive x-ray spectroscopy and XRD data for the EuCu2Sb2 crystals showed the presence of vacancies on the Cu sites, yielding themore » actual composition EuCu1.82Sb2. The ρ(T) and Cp(T) data reveal metallic character for both EuCu2As2 and EuCu1.82Sb2. Antiferromagnetic (AFM) ordering is indicated from the χ(T),Cp(T), and ρ(T) data for both EuCu2As2 (TN = 17.5 K) and EuCu1.82Sb2 (TN = 5.1 K). In EuCu1.82Sb2, the ordered-state χ(T) and M(H) data suggest either a collinear A-type AFM ordering of Eu+2 spins S = 7/2 or a planar noncollinear AFM structure, with the ordered moments oriented in the tetragonal ab plane in either case. This ordered-moment orientation for the A-type AFM is consistent with calculations with magnetic dipole interactions. As a result, the anisotropic χ(T) and isothermal M(H) data for EuCu2As2, also containing Eu+2 spins S = 7/2, strongly deviate from the predictions of molecular field theory for collinear AFM ordering and the AFM structure appears to be both noncollinear and noncoplanar.« less

  5. Antiferromagnetism in EuCu2As2 and EuCu1.82Sb2 single crystals

    NASA Astrophysics Data System (ADS)

    Anand, V. K.; Johnston, D. C.

    2015-05-01

    Single crystals of EuCu2As2 and EuCu2Sb2 were grown from CuAs and CuSb self-flux, respectively. The crystallographic, magnetic, thermal, and electronic transport properties of the single crystals were investigated by room-temperature x-ray diffraction (XRD), magnetic susceptibility χ versus temperature T , isothermal magnetization M versus magnetic field H , specific heat Cp(T ) , and electrical resistivity ρ (T ) measurements. EuCu2As2 crystallizes in the body-centered tetragonal ThCr2Si2 -type structure (space group I 4 /m m m ), whereas EuCu2Sb2 crystallizes in the related primitive tetragonal CaBe2Ge2 -type structure (space group P 4 /n m m ). The energy-dispersive x-ray spectroscopy and XRD data for the EuCu2Sb2 crystals showed the presence of vacancies on the Cu sites, yielding the actual composition EuCu1.82Sb2 . The ρ (T ) and Cp(T ) data reveal metallic character for both EuCu2As2 and EuCu1.82Sb2 . Antiferromagnetic (AFM) ordering is indicated from the χ (T ) ,Cp(T ) , and ρ (T ) data for both EuCu2As2 (TN=17.5 K) and EuCu1.82Sb2 (TN=5.1 K). In EuCu1.82Sb2 , the ordered-state χ (T ) and M (H ) data suggest either a collinear A-type AFM ordering of Eu+2 spins S =7/2 or a planar noncollinear AFM structure, with the ordered moments oriented in the tetragonal a b plane in either case. This ordered-moment orientation for the A-type AFM is consistent with calculations with magnetic dipole interactions. The anisotropic χ (T ) and isothermal M (H ) data for EuCu2As2 , also containing Eu+2 spins S =7/2 , strongly deviate from the predictions of molecular field theory for collinear AFM ordering and the AFM structure appears to be both noncollinear and noncoplanar.

  6. Antiferromagnetic Interlayer Exchange Coupling in All-Semiconducting EuS/PbS/EuS Trilayers

    NASA Technical Reports Server (NTRS)

    Smits, C. J. P.; Filip, A. T.; Swagten, H. J. M.; Koopmans, B.; deJonge, W. J. M.; Chernyshova, M.; Kowalczyk, L.; Grasza, K.; Szczerbakow, A.; Story, T.

    2003-01-01

    A comprehensive experimental study on the antiferromagnetic interlayer exchange coupling in high quality epitaxial all-semiconducting EuSPbSEuS trilayers is reported. The influence of substrates, the thickness of the non-magnetic PbS spacer layer, and of temperature, was investigated by means of SQUID magnetometry. In trilayers with a PbS thickness between 4 and 12 deg A the low temperature hysteresis loops showed the signature of antiferromagnetic coupling. The value of the interlayer exchange coupling energy was determined by simulating the data with a modified Stoner model, including Zeeman, anisotropy, and exchange coupling energies. An important observation was of a strong dependence of the interlayer exchange coupling energy on temperature, consistent with a power law dependence of the exchange coupling constant on the saturation magnetization of the EuS layers. While no theoretical description is readily available, we conjecture that the observed behavior is due to a dependence of the interlayer exchange coupling energy on the exchange splitting of the EuS conduction band.

  7. Two measured completely different electron affinities for atomic Eu?

    NASA Astrophysics Data System (ADS)

    Msezane, A. Z.; Felfli, Z.

    2016-05-01

    Recently, the electron affinity (EA) of atomic Eu was measured to be 0.116?eV. This value is in outstanding agreement with the theoretically calculated values using the Regge pole and MCDF-RCI methods. Previously, the EA of Eu was measured to be 1.053 eV. In an attempt to resolve the discrepancy between the two measured values, we have adopted the complex angular momentum (CAM) method and investigated in the electron energy range 0.11 eV Eu as Regge resonances following Ref.. We find the value of 2.63 eV as the EA of Eu. This leads us to conclude that neither the claimed measured EA of Eu correspond to the actual EA of Eu. We conclude that the EA in corresponds to the BE of an excited (metastable) state of the Euanion and that in to a shape resonance. We have also investigated the EA of atomic Nd and found the value of 1.88 eV, consistent with the measurement. These significant EA values of Eu and Nd could be important in the use of their negative ions in catalyzing the oxidation of water to peroxide and of methane to methanol without CO2 emission. These new results call for immediate experimental and theoretical verification.

  8. Optical Probing of metamagnetic phases in epitaxial EuSe

    SciTech Connect

    Galgano, G. D.; Henriques, A. B.; Bauer, G.; Springholz, G.

    2011-12-23

    EuSe is a wide gap magnetic semiconductors with a potential for applications in proof-of-concept spintronic devices. When the temperature is lowered, EuSe goes through sharp transitions between a variety of magnetic phases and is thus described as metamagnetic. The purpose of the present investigation is to correlate the magnetic order to the sharp dichroic doublet, discovered recently in high quality thin epitaxial layers of EuSe, grown by molecular beam epitaxy. We report detailed measurements of the doublet positions and intensities as a function of magnetic field in low temperatures, covering several magnetic phases.

  9. Synthesis YPO4:Eu3+ Nanophosphor from Fungi

    SciTech Connect

    Jia, George D

    2010-01-01

    Live fungi (zygo and asco) were cultivated and grown in an agar solution with a 2000 ppm concentration of Y3+ from YNO3 and a 20 ppm concentration of Eu3+ from EuNO3. When the fungi were grown to a good amount, they were collected, dried, and burnt at 1000 C for 2 h in air. X-ray diffraction, scanning electron microscopy, and optical spectroscopy experiments revealed that the product was nanophosphor YPO4:Eu3+ with a size of 100 200 nm.

  10. The new Zintl phases Eu21Cd4Sb18 and Eu21Mn4Sb18

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Darone, Gregory M.; Bobev, Svilen

    2016-06-01

    Crystals of two new Zintl compounds, Eu21Mn4Sb18 and Eu21Cd4Sb18 have been synthesized using the molten metal flux method, and their structures have been established by single-crystal X-ray diffraction. Both compounds are isotypic and crystallize in the monoclinic space group C2/m (No. 12, Z=4). The structures are based on edge- and corner-shared MnSb4 or CdSb4 tetrahedra, which make octameric [Mn8Sb22] or [Cd8Sb22] polyanions. Homoatomic Sb-Sb bonds are present in both structures. The Eu atoms take the role of Eu2+cations with seven unpaired 4f electrons, as suggested by the temperature-dependent magnetization measurements. The magnetic susceptibilities of Eu21Mn4Sb18 and Eu21Cd4Sb18 indicate that both phases order anti-ferromagnetically with Néel temperatures of ca. 7 K and ca. 10 K, respectively. The unpaired 3d electrons of the Mn atoms in Eu21Mn4Sb18 do contribute to the magnetic response, however, the bulk magnetization measurements do not provide evidence for long-range ordering of the Mn spins down to 5 K. Electrical resistivity measurements suggest that both compounds are narrow band gap semiconductors.

  11. Eu{sup 3+} luminescence enhancement by intercalation of benzenepolycarboxylic guests into Eu{sup 3+}-doped layered gadolinium hydroxide

    SciTech Connect

    Gu, Qingyang; Pan, Guohua; Ma, Teng; Huang, Gailing; Sun, Genban; Ma, Shulan; Yang, Xiaojing

    2014-05-01

    Graphical abstract: Two benzenepolycarboxylic sensitizers, 1,3,5-benzenetricarboxylic acid (BTA) and 1,2,4,5-benzenetetracarboxylic acid (BA), were intercalated into NO{sub 3}–LGdH:Eu, in which different structures of the compounds resulted in varied arrangement in the gallery. The two organic compounds especially BA markedly enhanced the red luminescence of Eu{sup 3+} due to efficient energy transfer between the organic guests and Eu{sup 3+} centers. - Highlights: • We report the intercalation of benzenepolycarboxylic organic sensitizers into LRH. • We study the intercalation structure and the arrangement of the interlayer guests. • The two organic compounds can markedly enhance the luminescence of Eu{sup 3+}. • There exists efficient energy transfer between organic guests and Eu{sup 3+} centers. • This material opens a route for fabricating new multifunctional luminescent materials. - Abstract: Two benzenepolycarboxylic organic sensitizers, 1,3,5-benzenetricarboxylic acid (BTA) and 1,2,4,5-benzenetetracarboxylic acid (BA), were intercalated into the gallery of NO{sub 3}{sup −} type Eu{sup 3+}-doped layered gadolinium hydroxide (NO{sub 3}–LGdH:Eu). CHN analysis, FTIR, and SEM were employed to characterize the intercalation structures of the as-prepared organic/inorganic hybrids. The area per unit charge (S{sub charge}) was used to explain the intercalation structure and the arrangement of the interlayer guests. Different structures of the two organic compounds resulted in varied arrangement of guests. Photoluminescence studies indicated that both of the two organic compounds especially BA markedly enhanced the red luminescence of Eu{sup 3+} due to efficient energy transfer between the organic guests and Eu{sup 3+} centers.

  12. High-Precision Measurement of Eu/Eu* in Geological Glasses via LA-ICP-MS Analysis

    NASA Technical Reports Server (NTRS)

    Tang, Ming; McDonough, William F.; Arevalo, Ricardo, Jr.

    2014-01-01

    Elemental fractionation during laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis has been historically documented between refractory and volatile elements. In this work, however, we observed fractionation between light rare earth elements (LREEs) and heavy rare earth elements (HREEs) when using ablation strategies involving large spot sizes (greater than 100 millimeters) and line scanning mode. In addition: (1) ion yields decrease when using spot sizes above 100 millimeters; (2) (Eu/Eu*)(sub raw) (i.e. Europium anomaly) positively correlates with carrier gas (He) flow rate, which provides control over the particle size distribution of the aerosol reaching the ICP; (3) (Eu/Eu*)(sub raw) shows a positive correlation with spot size, and (4) the changes in REE signal intensity, induced by the He flow rate change, roughly correlate with REE condensation temperatures. The REE fractionation is likely driven by the slight but significant difference in their condensation temperatures. Large particles may not be completely dissociated in the ICP and result in preferential evaporation of the less refractory LREEs and thus non-stoichiometric particle-ion conversion. This mechanism may also be responsible for Sm-Eu-Gd fractionation as Eu is less refractory than Sm and Gd. The extent of fractionation depends upon the particle size distribution of the aerosol, which in turn is influenced by the laser parameters and matrix. Ablation pits and lines defined by low aspect ratios produce a higher proportion of large particles than high aspect ratio ablation, as confirmed by measurements of particle size distribution in the laser induced aerosol. Therefore, low aspect ratio ablation introduces particles that cannot be decomposed and/or atomized by the ICP and thus results in exacerbated elemental fractionation. Accurate quantification of REE concentrations and Eu/Eu* requires reduction of large particle production during laser ablation. For the reference

  13. Unique Eu(II) Coordination Environments with a Janus Cryptand.

    PubMed

    Jin, Guo-Xia; Bailey, Matthew D; Allen, Matthew J

    2016-09-01

    Two new Eu(II)-containing cryptates were prepared with a new nitrogenous cryptand functionalized with three benzo groups. The introduction of three aromatic rings into the ligand backbone imparts lopsided geometrical features on the resulting Eu(II) coordination environments. In both complexes, the interactions between Eu and the amines on the aromatic side of the molecule are weaker than those on the nonaromatic side, resulting in one discrete unit with two distinct faces. One of the new complexes is, to the best of our knowledge, the first direct observation of a bis-aquo Eu(II)-containing cryptate with two nonadjacent inner-sphere water molecules. In addition to solid-phase structure, the electronic UV-visible and emission spectra of the new complexes were studied in acetonitrile. Experimental results show that the decreased Lewis basicity of the aromatic face hypsochromically shifts absorbances and emissions from a structurally related compound without the benzo groups. PMID:27548510

  14. Paradoxical EU agricultural policies on genetically engineered crops.

    PubMed

    Masip, Gemma; Sabalza, Maite; Pérez-Massot, Eduard; Banakar, Raviraj; Cebrian, David; Twyman, Richard M; Capell, Teresa; Albajes, Ramon; Christou, Paul

    2013-06-01

    European Union (EU) agricultural policy has been developed in the pursuit of laudable goals such as a competitive economy and regulatory harmony across the union. However, what has emerged is a fragmented, contradictory, and unworkable legislative framework that threatens economic disaster. In this review, we present case studies highlighting differences in the regulations applied to foods grown in EU countries and identical imported products, which show that the EU is undermining its own competitiveness in the agricultural sector, damaging both the EU and its humanitarian activities in the developing world. We recommend the adoption of rational, science-based principles for the harmonization of agricultural policies to prevent economic decline and lower standards of living across the continent. PMID:23623240

  15. Regionale Meeresschutzkooperation und die EU-Gratwanderung der Helsinki-Kommission imOsterweiterungsprozess der EU

    NASA Astrophysics Data System (ADS)

    Imhoff, Heike

    1999-12-01

    The purpose of the lecture is to describe the role of regional marine protection cooperation in the context of international cooperation. My intention is to provide evidence that regional forms of cooperation are an indispensable instrument, in particular against the backdrop of the EU enlargement to the east. Signed at times when the iron curtain still existed, the Baltic Marine Environment Protection Convention was the basis of a first reluctant cooperation between Western and Eastem states bordering on the Baltic Sea. As a result of the fall of the iron curtain and of the accession of Finland and Sweden to the European Union there was a shift in the political structure of the Baltic Sea cooperation. 4 EU member states are represented in the Helsinki Commission. As there is a total of 10 Parties (one of them the Commission of the European Communities) this means that EU countries currently already make up 50% of the Commission. The regulatory instruments of the Helsinki Commission (legally non-binding, yet politically appellative recommendations) and of the EU (directives, regulations etc. which are binding by international law) make it clear that there are serious differences. From the point of view of regional marine protection cooperation, the EC Commission’s involvement in issues of regional marine protection has been linked to both advantages and disadvantages. The pressure created by the EC’s involvement in certain issues can be considered an advantage, since it requires that certain issues are continually addressed in the framework of regional marine protection cooperation. For example, in the wake of the adoption of the nitrates directive special rules were established in the framework of the Helsinki Commission. However, the exclusive competence for individual areas (e.g. fisheries) claimed by the EC Commission sometimes has negative effects. Those member states of the Helsinki Commission which are also EU member states may formally only accept rules

  16. Partitioning of Eu between augite and a highly spiked martian basalt composition as a function of oxygen fugacity (IW-1 to QFM): Determination of Eu[superscript 2+]/Eu[superscript 3+] ratios by XANES

    SciTech Connect

    Karner, J.M.; Papike, J.J.; Sutton, S.R.; Burger, P.V.; Shearer, C.K.; Le, L.; Newville, M.; Choi, Y.

    2010-03-16

    We have determined D{sub Eu} between augite and melt in samples that crystallized from a highly spiked martian basalt composition at four f{sub O{sub 2}} conditions. D{sub Eu} augite/melt shows a steady increase with f{sub O{sub 2}} from 0.086 at IW-1 to 0.274 at IW+3.5. This increase is because Eu{sup 3+} is more compatible than Eu{sup 2+} in the pyroxene structure; thus increasing f{sub O{sub 2}} leads to greater Eu{sup 3+}/Eu{sup 2+} in the melt and more Eu (total) can partition into the crystallizing pyroxene. This interpretation is supported by direct determinations of Eu valence state by XANES, which show a steady increase of Eu{sup 3+}/Eu{sup 2+} with increasing f{sub O{sub 2}} in both pyroxene (0.38 to 14.6) and glass (0.20 to 12.6) in the samples. Also, pyroxene Eu{sup 3+}/Eu{sup 2+} is higher than that of adjacent glass in all the samples, which verifies that Eu{sup 3+} is more compatible than Eu{sup 2+} in the pyroxene structure. Combining partitioning data with XANES data allows for the calculation of specific valence state D-values for augite/melt where D{sub Eu{sup 3+}} = 0.28 and D{sub Eu{sup 2+}} = 0.07.

  17. Enhancing Eu(3+) magnetic dipole emission by resonant plasmonic nanostructures.

    PubMed

    Hussain, Rabia; Kruk, Sergey S; Bonner, Carl E; Noginov, Mikhail A; Staude, Isabelle; Kivshar, Yuri S; Noginova, Natalia; Neshev, Dragomir N

    2015-04-15

    We demonstrate the enhancement of magnetic dipole spontaneous emission from Eu3+ ions by an engineered plasmonic nanostructure that controls the electromagnetic environment of the emitter. Using an optical microscope setup, an enhancement in the intensity of the Eu3+ magnetic dipole emission was observed for emitters located in close vicinity to a gold nanohole array designed to support plasmonic resonances overlapping with the emission spectrum of the ions. PMID:25872041

  18. EU Failing FAO Challenge to Improve Global Food Security.

    PubMed

    Smyth, Stuart J; Phillips, Peter W B; Kerr, William A

    2016-07-01

    The announcement that the European Union (EU) had reached an agreement allowing Member States (MS) to ban genetically modified (GM) crops confirms that the EU has chosen to ignore the food security challenge issued to the world by the Food and Agriculture Organization of the United Nations (FAO) in 2009. The FAO suggests that agricultural biotechnology has a central role in meeting the food security challenge. PMID:27318260

  19. A System of Systems Approach to the EU Energy System

    NASA Astrophysics Data System (ADS)

    Jess, Tom; Madani, Kaveh; Mahlooji, Maral; Ristic, Bora

    2016-04-01

    Around the world, measures to prevent dangerous climate change are being adopted and may change energy systems fundamentally. The European Union (EU) is committed to reducing greenhouse gas emission by 20% by 2020 and by 80-95% by 2050. In order to achieve this, EU member states aim to increase the share of renewables in the energy mix to 20% by 2020. This commitment comes as part of a series of other aims, principles, and policies to reform the EU's energy system. Cost-efficiency in the emissions reductions measures as well as strategic goals under the Resource Efficient Europe flagship initiative which would include a more prudent approach to other natural resources such as water and land. Using the "System of Systems Approach", as from Hadian and Madani (2015), energy sources' Relative Aggregate Footprints (RAF) in the EU are evaluated. RAF aggregates across four criteria: carbon footprint, water footprint, land footprint, and economic cost. The four criteria are weighted by resource availability across the EU and for each Member State. This provides an evaluation of the overall resource use efficiency of the EU's energy portfolio and gives insight into the differences in the desirability of energy sources across Member States. Broadly, nuclear, onshore wind, and geothermal are most desirable under equal criteria weights and EU average weighting introduces only small changes in the relative performance of only few technologies. The member state specific weightings show that most countries have similar energy technology preferences. However, the UK deviates most strongly from the average, with an even stronger preference for nuclear and coal. Sweden, Malta and Finland also deviate from the typical preferences indicating the complexity in play in reforming the EU energy system. Reference Hadian S, Madani K (2015) A System of Systems Approach to Energy Sustainability Assessment: Are All Renewables Really Green? Ecological Indicators, 52, 194-206.

  20. Could EU herbal monographs contribute to Malta's treatment armamentarium?

    PubMed

    Micallef, B; Attard, E; Serracino-Inglott, A; Borg, J J

    2015-03-15

    Ten years have passed since Directive 2004/24/EC regulating herbal medicinal products across the EU were published. The directive created the Committee on Herbal Medicinal Products within the European Medicines Agency whose remit includes the creation and publishing of official EU monographs on herbal medicinal products. These monographs include the official uses of the products and their evidence for efficacy and safety. To this effect, we are interested in analysing the potential impact herbal product EU monographs could have on the therapeutic treatment options available for prescribers in Malta. Therefore our aim was two-fold. First, to rationalise the spread of indications of the herbal substances listed in the community herbal monograph inventory and subsequently determine if these herbal substances could potentially contribute to the treatment options available in our local scenario (Malta). 128 EU monographs were analysed resulting in a total of 230 indications which subsequently codified into 42 unique ATC codes. The Malta Medicines List contains 1456 unique ATC codes. Comparative analysis of the Malta Medicines List revealed that the 21 therapeutic areas had 4 or less pharmaceutically used substances (5th level ATC codes) registered and therefore in our opinion are areas with limited therapeutic choice. The following 4 therapeutic areas, A05 bile and liver therapy, A13 tonics, A15 appetite stimulants and D03 preparations for treatment of wounds and ulcers, could potentially benefit from the registration of herbal medicinal products according to the EU herbal monographs. If such registration is effected the aforementioned areas would no longer be considered limited because more than 4 therapeutic choices would be available to prescribers. This study is the first study across the EU to analyse the potential impact of published EU herbal monographs on therapeutic coverage in an EU member state and confirms the notion that herbal products could potentially

  1. Overview of Botanical Status in EU, USA, and Thailand

    PubMed Central

    Mahady, Gail B.

    2013-01-01

    The botanical status in EU, USA, and Thailand is different owing to the regulatory status, the progress of science, and the influence of culture and society. In the EU, botanicals are positioned as herbal medicinal products and food supplements, in the US they are regulated as dietary supplements but often used as traditional medicines, and in Thailand, they are regulated and used as traditional medicines. Information for some of the most popular botanicals from each country is included in this review. PMID:24228061

  2. A {sup 151}Eu Moessbauer spectroscopic and magnetic susceptibility investigation of the intermetallic compounds EuTIn (T = Zn, Pd, Pt, Au)

    SciTech Connect

    Muellmann, R.; Mosel, B.D.; Eckert, H.; Kotzyba, G.; Poettgen, R.

    1998-04-01

    The title compounds were investigated by magnetic susceptibility measurements and {sup 151}Eu Moessbauer spectroscopy. EuZnIn and EuPtIn show Curie-Weiss behavior above 60 K with experimental magnetic moments of 7.80(5) and 8.0(1) {mu}{sub B}/Eu, respectively, indicating divalent europium. The zinc compound orders antiferromagnetically at T{sub N} = 8.0(5) k and two metamagnetic transitions are detected at the critical field strengths B{sub C1} = 1.1(1) T and B{sub C2} = 2.6(2) T. At 5 K the saturation magnetic moment amounts to 7.0(1) {mu}{sub B}/Eu, suggesting a full parallel spin alignment. EuPdIn and EuAuIn order antiferromagnetically at 13.0(5) and 21.0(5) K in low external magnetic fields, respectively. The four compounds are metallic conductors. The Moessbauer measurements of the EuTIn compounds show {sup 151}Eu isomer shifts typical of divalent europium. The isomer shifts are found to linearly correlated with the closest Eu-Eu distance in the structure. Based on the Moessbauer data the onset of magnetic order is observed at T{sub N}(EuZnIn) = 9.5(5) K, T{sub N}(EuPdIn) = 15.5(5) K, T{sub N}(EuAuIn) = 20.0(5) K, and T{sub N}(EuPtIn) = 20.0(5) K, respectively. The magnetically split spectrum of EuZnIn reveals evidence of Eu site inequivalence.

  3. Radiation stability of CsBr:Eu needle image plates

    SciTech Connect

    Batentschuk, M.; Neudert, S.; Weidner, M.; Osvet, A.; Struye, L.; Tahon, J.-P.; Leblans, P.

    2009-10-15

    Needle image plates (NIPs) based on CsBr:Eu are a good alternative to the BaFBr:Eu powder image plates due to their higher sensitivity and improved spatial resolution. The x-ray radiation stability of the NIPs produced by Agfa Gevaert was investigated and it was found that the radiation stability of the optimized NIPs is as high as that of the commercial CsI:Tl single crystals and much higher than reported in literature for the CsBr:Eu NIPs. The dependence of the sensitivity of the NIPs on the accumulated dose was determined for three different types of x-ray irradiation. It is shown that degradation of the sensitivity starts at about 10 Gy and it is the strongest for the most hard x-ray beam. If the energy absorbed by a NIP is taken into account, the degradation does not depend on the hardness of the applied x-ray beam. It is suggested that the main reason for the observed high radiation stability of the CsBr:Eu NIPs is the use of the oxygen-free Eu{sup 2+}-containing precursor CsEuBr{sub 3} for the doping in the manufacturing process.

  4. Optical Study of Archetypical Valence-Fluctuating Eu Systems

    NASA Astrophysics Data System (ADS)

    Guritanu, V.; Seiro, S.; Sichelschmidt, J.; Caroca-Canales, N.; Iizuka, T.; Kimura, S.; Geibel, C.; Steglich, F.

    2012-12-01

    We have investigated the optical conductivity of the prominent valence-fluctuating compounds EuIr2Si2 and EuNi2P2 in the infrared energy range to get new insights into the electronic properties of valence-fluctuating systems. For both compounds, we observe upon cooling the formation of a renormalized Drude response, a partial suppression of the optical conductivity below 100meV, and the appearance of a midinfrared peak at 0.15eV for EuIr2Si2 and 0.13 eV for EuNi2P2. Most remarkably, our results show a strong similarity with the optical spectra reported for many Ce- or Yb-based heavy-fermion metals and intermediate valence systems, although the phase diagrams and the temperature dependence of the valence differ strongly between Eu systems and Ce- or Yb-based systems. This suggests that the hybridization between 4f and conduction electrons, which is responsible for the properties of Ce and Yb systems, plays an important role in valence-fluctuating Eu systems.

  5. Eu2+-->Mn2+ energy transfer in NaCl

    NASA Astrophysics Data System (ADS)

    Rubio O., J.; Murrieta S., H.; Powell, R. C.; Sibley, W. A.

    1985-01-01

    Crystals of NaCl containing different concentrations of Eu2+ and Mn2+ ions (the Eu concentration always being less than that of Mn) were investigated by optical and EPR spectroscopy. The results show that Eu2+-Mn2+ pairs form preferentially in this material and that highly efficient energy transfer occurs from the Eu2+ ions to the near-neighbor Mn2+ ions. Over 99% of the Eu2+ ions are paired, and these pairs are not significantly affected by the state of aggregation of the Mn ions, although in the various samples evidence for manganese ions in their dipolar state, as well as precipitated into the Suzuki phase, exists. The excitation spectra of the orange manganese emission show, in addition to the Eu2+ 4f7-->4f65d transitions, Mn2+ transitions associated with the Suzuki phase and with Mn2+-cation vacancy dipoles. The peak positions of these Mn2+-crystal-field-sensitive transitions were fitted theoretically with expressions including Racah-Tress and seniority corrections. This procedure allowed the determination of the relevant crystal-field parameters.

  6. Supporting health systems in Europe: added value of EU actions?

    PubMed

    Clemens, Timo; Michelsen, Kai; Brand, Helmut

    2014-01-01

    Since the start of the economic crisis, the European Union's (EU's) predominant discourse has been austerity and fiscal consolidation. The detrimental effects on Europe's health systems and the health status of its citizens are well described. However, little is known about the emerging EU-level initiatives to support national health systems handle the challenges of efficient care provision and system reorganisation aimed to meet their future needs. This review analyses the manner, conditions and prospects of such EU support. First, health system objectives are increasingly entering the EU health policy agenda. Second, professional and patient mobility provisions may support member states (MS) in copying with crisis related health challenges but can potentially acerbate them at the same time. Third, in recent initiatives health system goals are more closely tied to the EU's economic growth narrative. And fourth, health system issues are taken up in existing EU-level structures for debate and exchange between MS. In addition, the design of some policies may have the potential to intensify socioeconomic and health inequalities rather than ameliorate them. PMID:23968231

  7. Metastable states in InGaN/GaN MQW structures doped with Sm, Eu, and Eu + Sm

    SciTech Connect

    Mezdrogina, M. M.; Kozhanova, Yu. V.

    2013-04-15

    Measurements of the microphotoluminescence (microPL) spectra of InGaN/GaN:Sm and InGaN/GaN:Eu quantum well (QW) structures show that the action of a magnetic field gives rise to Van Vleck paramagnetism for Eu{sup 3+} and Sm{sup 3+}. The macrophotoluminescence (macroPL) spectra recorded after measuring the microPL spectra of InGaN/GaN QW structures doped with Sm or Eu + Sm at a high excitation level (>10{sup 23} photons cm{sup -2} s{sup -1}) in magnetic fields contain no QW emission lines which are present in the macroPL spectra recorded before these microPL measurements. This is indicative of the presence of photoinduced defects. Annealing of the InGaN/GaN:Sm and InGaN/GaN:(Eu + Sm) structures reduces the concentration of photoinduced defects.

  8. New localized/delocalized emitting state of Eu2+ in orange-emitting hexagonal EuAl2O4

    DOE PAGESBeta

    Liu, Feng; Meltzer, Richard S.; Li, Xufan; Budai, John D.; Chen, Yu -Sheng; Pan, Zhengwei

    2014-11-18

    Eu2+-activated phosphors are being widely used in illuminations and displays. Some of these phosphors feature an extremely broad and red-shifted Eu2+ emission band; however, convincing explanation of this phenomenon is lacking. Here we report a new localized/delocalized emitting state of Eu2+ ions in a new hexagonal EuAl2O4 phosphor whose Eu2+ luminescence exhibits a very large bandwidth and an extremely large Stokes shift. At 77 K, two luminescent sites responsible for 550 nm and 645 nm broadband emissions are recognized, while at room temperature only the 645 nm emission band emits. The 645 nm emission exhibits a typical radiative lifetime ofmore » 1.27 μs and an unusually large Stokes shift of 0.92 eV. We identify the 645 nm emission as originating from a new type of emitting state whose composition is predominantly that of localized 4f65d character but which also contains a complementary component with delocalized conduction-band-like character. This investigation gives new insights into a unique type of Eu2+ luminescence in solids whose emission exhibits both a very large bandwidth and an extremely large Stokes shift.« less

  9. New localized/delocalized emitting state of Eu2+ in orange-emitting hexagonal EuAl2O4

    PubMed Central

    Liu, Feng; Meltzer, Richard S.; Li, Xufan; Budai, John D.; Chen, Yu-Sheng; Pan, Zhengwei

    2014-01-01

    Eu2+-activated phosphors are being widely used in illuminations and displays. Some of these phosphors feature an extremely broad and red-shifted Eu2+ emission band; however, convincing explanation of this phenomenon is lacking. Here we report a new localized/delocalized emitting state of Eu2+ ions in a new hexagonal EuAl2O4 phosphor whose Eu2+ luminescence exhibits a very large bandwidth and an extremely large Stokes shift. At 77 K, two luminescent sites responsible for 550 nm and 645 nm broadband emissions are recognized, while at room temperature only the 645 nm emission band emits. The 645 nm emission exhibits a typical radiative lifetime of 1.27 μs and an unusually large Stokes shift of 0.92 eV. We identify the 645 nm emission as originating from a new type of emitting state whose composition is predominantly that of localized 4f65d character but which also contains a complementary component with delocalized conduction-band-like character. This investigation provides new insights into a unique type of Eu2+ luminescence in solids whose emission exhibits both a very large bandwidth and an extremely large Stokes shift. PMID:25403911

  10. India-EU relations in health services: prospects and challenges

    PubMed Central

    2011-01-01

    Background India and the EU are currently negotiating a Trade and Investment Agreement which also covers services. This paper examines the opportunities for and constraints to India-EU relations in health services in the context of this agreement, focusing on the EU as a market for India's health services exports and collaboration. The paper provides an overview of key features of health services in the EU and India and their bearing on bilateral relations in this sector. Methods Twenty six semi-structured, in-person, and telephonic interviews were conducted in 2007-2008 in four Indian cities. The respondents included management and practitioners in a variety of healthcare establishments, health sector representatives in Indian industry associations, health sector officials in the Indian government, and official representatives of selected EU countries and the European Commission based in New Delhi. Secondary sources were used to supplement and corroborate these findings. Results The interviews revealed that India-EU relations in health services are currently very limited. However, several opportunity segments exist, namely: (i) Telemedicine; (ii) Clinical trials and research in India for EU-based pharmaceutical companies; (iii) Medical transcriptions and back office support; (iv) Medical value travel; and (v) Collaborative ventures in medical education, research, training, staff deployment, and product development. However, various factors constrain India's exports to the EU. These include data protection regulations; recognition requirements; insurance portability restrictions; discriminatory conditions; and cultural, social, and perception-related barriers. The interviews also revealed several constraints in the Indian health care sector, including disparity in domestic standards and training, absence of clear guidelines and procedures, and inadequate infrastructure. Conclusions The paper concludes that although there are several promising areas for India-EU

  11. Blue emission of Eu2+-doped translucent alumina

    DOE PAGESBeta

    Yang, Yan; Zhang, Lihua; Kisslinger, Kim; Wei, Hua; Melcher, Charles L.; Wu, Yiquan

    2015-08-21

    Inorganic scintillators are very important in medical and industrial measuring systems in the detection and measurement of ionizing radiation. In addition to Ce3+, a widely used dopant ion in oxide scintillators, divalent Europium (Eu2+) has shown promise as a high-luminescence, fast-response luminescence center useful in the detection of ionizing radiation. In this research, aluminum oxide (Al2O3) was studied as a host material for the divalent europium ion. Polycrystalline samples of Eu2+-doped translucent Al2O3 were fabricated, and room temperature luminescence behavior was observed. Al2O3 ceramics doped with 0.1 at% Eu2+ were fabricated with a relative density of 99.75% theoretical density andmore » in-line transmittance of 22% at a wavelength of 800 nm. The ceramics were processed by a gel-casting method, followed by sintering under high vacuum. The gelling agent, a copolymer of isobutylene and maleic anhydride, is marketed under the commercial name ISOBAM, and has the advantage of simultaneously acting as both a gelling agent and as a dispersant. The microstructure and composition of the vacuum-sintered Eu2+:Al2O3 were characterized by Scanning Electric Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-dispersive X-ray spectroscopy (EDS). The phase composition was determined by X-ray diffraction measurements (XRD) combined with Rietveld analysis. The photoluminescence behavior of the Eu2+:Al2O3 was characterized using UV light as the excitation source, which emitted blue emission at 440 nm. The radio-luminescence of Eu2+:Al2O3 was investigated by illumination with X-ray radiation, showing three emission bands at 376 nm, 575 nm and 698 nm. Furthermore, multiple level traps at different depths were detected in the Eu2+:Al2O3 by employing thermoluminescence measurements.« less

  12. Decay studies of neutron deficient nuclei near the Z=64 subshell: 142Dy, 140,142Tb, 140,142Gd, 140,142Eu, 142Sm, and 142Pm

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Gilat, J.; Nitschke, J. M.; Wilmarth, P. A.; Vierinen, K. S.

    1991-03-01

    The electron-capture and β+-decay branchings (EC/β+) and delayed proton decays of A=142 isotopes with 61<=Z<=66 and A=140 isotopes with 63<=Z<=65 were investigated with the OASIS facility on-line at the Lawrence Berkeley Laboratory SuperHILAC. Electron capture and positron-decay emission probabilities have been determined for 142Pm and 142Sm decays, and extensive decay schemes have been constructed for 142Eug(2.34+/-0.12 s), 142Gd(70.2+/-0.6 s), 140Eu(1.51+/-0.02 s), and 140Gd(15.8+/-0.4 s). Decay schemes for the new isotopes 142Tbg(597+/-17 ms), 142Tbm(303+/-17 ms), 142Dy(2.3+/-0.3 s), 140Eum(125+/-2 ms), and 140Tb(2.4+/-0.2 s) are also presented. We have assigned γ rays to these isotopes on the basis of γγ and xγ coincidences, and from half-life determinations. Electron-capture and β+-decay branchings were measured for each decay, and β-delayed proton branchings were determined for 142Dy, 142Tb, and 140Tb decays. QEC values, derived from the measured EC/β+ branchings and the level schemes are compared with those from the Wapstra and Audi mass evaluation and the Liran and Zeldes mass calculation. The systematics of the N=77 isomer decays are discussed, and the intense 0+-->1+ and 1+-->0+ ground-state beta decays are compared with shell-model predictions for simple spin-flip transitions.

  13. Quantifying the influence of the tobacco industry on EU governance: automated content analysis of the EU Tobacco Products Directive

    PubMed Central

    Costa, Hélia; Gilmore, Anna B; Peeters, Silvy; McKee, Martin; Stuckler, David

    2014-01-01

    Objective The tobacco industry spends large sums lobbying the European Union (EU) institutions, yet whether such lobbying significantly affects tobacco policy is not well understood. We used novel quantitative text mining techniques to evaluate the impact of industry pressure on the contested EU Tobacco Products Directive revision. Design Policy positions of 18 stakeholders including the tobacco industry, health NGOs and tobacco retailers were evaluated using their text submissions to EU consultations and impact assessments. Using Wordscores to calculate word frequencies, we developed a scale ranging from 0–tobacco industry to 1–public health organisations, which was then used to track changes in the policy position of the European Commission's 2010 consultation document, its 2012 final proposal and the European Parliament and Council's approved legislation in March 2014. Results Several stakeholders’ positions were closer to the tobacco industry than that of health NGOs, including retailers (ω=0.35), trade unions (ω=0.34) and publishers (ω=0.33 and ω=0.40). Over time the European Commission's position shifted towards the tobacco industry from ω=0.52 (95% CI 0.50 to 0.54) to ω=0.40 (95% CI 0.39 to 0.42). This transition reflected an increasing use of words pertaining to business and the economy in the Commission's document. Our findings were robust to alternative methods of scoring policy positions in EU documents. Conclusions Using quantitative text mining techniques, we observed that tobacco industry lobbying activity at the EU was associated with significant policy shifts in the EU Tobacco Products Directive legislation towards the tobacco industry's submissions. In the light of the Framework Convention on Tobacco Control, additional governance strategies are needed to prevent undue influence of the tobacco industry on EU policy making. PMID:25124165

  14. Anisotropic magnetic properties of EuAl2Si2

    NASA Astrophysics Data System (ADS)

    Maurya, Arvind; Kulkarni, Ruta; Thamizhavel, A.; Bonville, P.; Dhar, S. K.

    2015-03-01

    EuAl2Si2 is known to crystallize in the CaAl2Si2-type trigonal structure. We have grown single crystals of EuAl2Si2 by flux method, using Al-Si eutectic (87.8% Al) as self-flux, and investigated their anisotropic magnetic properties by means of magnetization, electrical resistivity and heat capacity in zero and applied magnetic fields, and 151Eu Mössbauer spectroscopy. Magnetic susceptibility data show an antiferromagnetic transition at TN = 33.3 K in agreement with the previously reported value on polycrystalline sample. The isothermal magnetization at 2 K measured along and perpendicular to the c-axis shows anisotropic behaviour, which is rather unexpected as Eu2+ is an S-state ion. The spin flip fields along the two directions are 2.8 and 4.8 T, respectively, while two closely spaced spin-flop transitions in the ab-plane are observed near 1.4 and 1.6 T. The electrical resistivity shows an upturn between TN and 60 K as the temperature is lowered below ~ 60 K, suggesting the presence of antiferromagnetic correlations in the paramagnetic state. Magnetoresistivity at 2 K in 14 T is nearly 1070 % for H // [0001]. The results of heat capacity and 151Eu Mössbauer spectroscopy are in conformity with a bulk transition at 33.3 K.

  15. Structural coupling across the direct EuO/Si interface

    NASA Astrophysics Data System (ADS)

    Averyanov, Dmitry V.; Tokmachev, Andrey M.; Likhachev, Igor A.; Lobanovich, Eduard F.; Parfenov, Oleg E.; Pashaev, Elkhan M.; Sadofyev, Yuri G.; Subbotin, Ilia A.; Yakunin, Sergey N.; Storchak, Vyacheslav G.

    2016-01-01

    The ferromagnetic semiconductor EuO is believed to be an effective spin injector when directly integrated with silicon (Si). Injection through spin-selective ohmic contact requires superb structural quality of the interface EuO/Si. A recent breakthrough in manufacturing free-of-buffer-layer EuO/Si junctions calls for structural studies of the interface between the semiconductors. The synthesis of EuO employs an advanced protection of the Si substrate surface and a two-step growth protocol. It prevents unwanted chemical reactions at the interface. Ex situ high-resolution x-ray diffraction (XRD) and reflectivity (XRR) accompanied by in situ reflection high-energy electron diffraction reveal direct coupling at the interface. A combined analysis of XRD and XRR data provides a common structural model. The structural quality of the EuO/Si spin contact far exceeds that of previous reports and thus makes a step forward to the ultimate goals of spintronics.

  16. Characterization of the Advanced Stirling Radioisotope Generator EU2

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Nicholas A.

    2015-01-01

    Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA GRC recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's ASC-E3 Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included: measurement of convertor, controller, and generator performance and efficiency, quantification of control authority of the controller, disturbance force measurement with varying piston phase and piston amplitude, and measurement of the effect of spacecraft DC bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

  17. Moessbauer Effects and Magnetic Properties of Mixed Valent Europium Sulfide, EuPd

    SciTech Connect

    Wakeshima, Makoto; Doi, Yoshihiro; Hinatsu, Yukio

    2001-02-15

    EuPd{sub 3}S{sub 4} with a NaPt{sub 3}O{sub 4}-type structure was investigated by X-ray diffraction, {sup 151}Eu Moessbauer spectroscopy, magnetic susceptibility, and specific heat measurements. In this compound, Eu{sup 2+} and Eu{sup 3+} ions exist in the ratio of ca. 1:1. The Debye temperatures of Eu{sup 2+} and Eu{sup 3+} were determined to be 195 and 220 K, respectively. The isomer shift of Eu{sup 2+} in this EuPd{sub 3}S{sub 4} at 300 K is largest among Eu{sup 2+} sulfides because of the compression effect of the Eu{sup 2+} sites. The temperature dependence of the isomer shifts suggests that a hopping of the electron between Eu{sup 2+} and Eu{sup 3+} occurs in EuPd{sub 3}S{sub 4}. The Eu{sup 2+} ion was found to be in the antiferromagnetic state below 3 K from both the magnetic susceptibility and specific heat measurements.

  18. Magnetic properties and complex magnetic phase diagram in non-centrosymmetric EuRhGe3 and EuIrGe3 single crystals

    NASA Astrophysics Data System (ADS)

    Maurya, Arvind; Bonville, P.; Kulkarni, R.; Thamizhavel, A.; Dhar, S. K.

    2016-03-01

    We report the magnetic properties of two Eu based compounds, single crystalline EuIrGe3 and EuRhGe3, inferred from magnetisation, electrical transport, heat capacity and 151Eu Mössbauer spectroscopy. These previously known compounds crystallise in the non-centrosymmetric, tetragonal, I4 mm, BaNiSn3-type structure. Single crystals of EuIrGe3 and EuRhGe3 were grown using a high temperature solution growth method using In as flux. EuIrGe3 exhibits two magnetic transition temperatures TN1 = 12.4 K, and TN 2 = 7.3 K, whereas EuRhGe3 presents a single one at TN = 12 K. 151Eu Mössbauer spectra show evidence for a cascade of transitions from paramagnetic to incommensurate amplitude modulated followed by an equal moment phase at lower temperature in EuIrGe3. This latter phase alone occurs in EuRhGe3. In both compounds, the magnetisation measured up to 14 T suggests that the equal moment magnetic phase has a spiral spin arrangement. The field induced reorientations are also well documented in the magnetotransport data. A superzone gap is observed for the current density J ∥ [001], which is enhanced by a transverse magnetic field. The magnetic phase diagram constructed from all the data is complex, revealing the presence of many phases in the H - T space.

  19. Massive production of A2SiO4:Eu3+ and A2SiO4:Eu2+ (A = Ca, Sr, Ba) microspheres and luminescent properties

    NASA Astrophysics Data System (ADS)

    Wei, Fengjun; Jia, Qiuli

    2015-06-01

    A2SiO4:Eu3+ and A2SiO4:Eu2+ (A = Ca, Sr, Ba) microspheres with dense structure were synthesized by the modified spray-drying process. The obtained samples were characterized by XRD, SEM, and spectrophotometer. The XRD results reveal that all samples are isostructure. The SEM results show that the obtained samples are microspheres with size in the range of 0.6-2.2 μm. Dextrin plays an important role in the formation of spherical morphology. The excitation and emission spectra of the samples indicate that Eu3+ (or Eu2+) ions doped into different alkaline earth silicates will give different emission bands in different color regions and with different emission intensities. A2SiO4:Eu3+ samples show characteristic emission bands originating from 5D0 → 7Fj transitions of Eu3+ ions. A2SiO4:Eu2+ samples show different emission bands. The two emission bands for Sr2SiO4:Eu2+ relate to the two Eu2+ activator sites locating at two Sr2+ sites in Sr2SiO4 host. The difference of luminescent properties relates to the different sites of Eu3+ (or Eu2+) ions in the A2SiO4 hosts.

  20. Local validation of EU-DEM using Least Squares Collocation

    NASA Astrophysics Data System (ADS)

    Ampatzidis, Dimitrios; Mouratidis, Antonios; Gruber, Christian; Kampouris, Vassilios

    2016-04-01

    In the present study we are dealing with the evaluation of the European Digital Elevation Model (EU-DEM) in a limited area, covering few kilometers. We compare EU-DEM derived vertical information against orthometric heights obtained by classical trigonometric leveling for an area located in Northern Greece. We apply several statistical tests and we initially fit a surface model, in order to quantify the existing biases and outliers. Finally, we implement a methodology for orthometric heights prognosis, using the Least Squares Collocation for the remaining residuals of the first step (after the fitted surface application). Our results, taking into account cross validation points, reveal a local consistency between EU-DEM and official heights, which is better than 1.4 meters.

  1. Photostimulated luminescence properties of Eu2+ -doped barium aluminate phosphor.

    PubMed

    He, Quanlong; Qiu, Guangyu; Xu, Xuhui; Qiu, Jianbei; Yu, Xue

    2015-03-01

    An intense green photostimulated luminescence in BaAl2 O4 :Eu(2+) phosphor was prepared. The thermoluminescence results indicate that there are at least three types of traps (T1 , T2 , T3 ) with different trap depths in BaAl2 O4 :Eu(2+) phosphor according to the bands located at 327, 361 and 555 K, respectively, which are closely associated with the phosphor's long persistent luminescence and photostimulated luminescence properties. In addition, as a novel optical read-out form, a photostimulated persistent luminescence signal can be repeatedly obtained in BaAl2 O4 :Eu(2+) phosphor. This shows that re-trapping of the electron released from a deep trap plays an important role in photostimulated persistent luminescence. PMID:24954192

  2. BaBrI:Eu2 + , a new bright scintillator

    SciTech Connect

    Bourret-Courchesne, E.D.; Bizarri, G.; Hanrahan, S.M.; Gundiah, G.; Yan, Z.; Derenzo, S.E.

    2009-11-07

    The scintillation properties of BaBrI:Eu2+ are reported. Crystals were produced by the vertical Bridgman technique in a sealed quartz ampoule. Excellent scintillation properties were measured. A light yield of 81,0007 +- 3000 photons per MeV (ph/MeV) of absorbed gamma-ray energy was measured. An energy resolution (FWHM over peak position) of 4.870.5percent was observed for the 662keV full absorption peak. Pulsed X-ray luminescence measurements show two exponential decay components of 297 and 482 ns with a contribution to the total light output of 23percent and 77percent, respectively. Under X-ray and UV excitation, the emission corresponds to a broadband center at 413 nm. These initial values make BaBrI:Eu2+ one of the brightest and the fastest known Eu2+ doped scintillators.

  3. Crystal cluster growth and physical properties of the EuSbSe3 and EuBiSe3 phases.

    PubMed

    Forbes, Scott; Tseng, Yu-Chih; Mozharivskyj, Yurij

    2015-02-01

    Syntheses of europium metal, selenium powder, and the Sb(2)Se(3)/Bi(2)Se(3) binaries were observed to produce crystal clusters of the EuSbSe(3) and EuBiSe(3) phases. These phases crystallize with the P2(1)2(1)2(1) space group and can be easily identified based on their growth habits, forming large clusters of needles. Previous literature suggested that their structure is charge-balanced with all europium atoms in the divalent state and one-quarter of the selenium atoms forming trimers. Physical property measurements on a pure sample of EuSbSe(3) revealed typical Arrhenius-type electrical resistivity, being approximately 3 orders of magnitude too large for thermoelectric applications. Electronic structure calculations indicated that both EuSbSe(3) and EuBiSe(3) are narrow-band-gap semiconductors, in good agreement with the electrical resistivity data. The valence and conduction band states near the Fermi level are dominated by the Sb/Bi and Se p states, as expected given their small difference in electronegativity. PMID:25255124

  4. Probing dual mode emission of Eu3+ in garnet phosphor

    NASA Astrophysics Data System (ADS)

    Singh, S. K.; Gi Lee, Dong; Soo Yi, Soung; Jang, Kiwan; Shin, Dong-Soo; Hyun Jeong, Jung

    2013-05-01

    Eu3+ doped and Eu3+, Yb3+ co-doped Gd3Ga5O12 phosphors have been developed by facile solid state reaction method which can be easily scaled-up in large quantity. The synthesis has been optimized to get a single phase material at 1300 °C. The phase and crystal parameters have been analyzed by using X-ray diffraction measurement. Photoluminescence excitation (monitored for the 5D0 → 7F1 transition of Eu3+) depicts that the active ion (Eu3+) can be excited through direct excitation into 4f band of Eu3+, through charge transfer band (Eu3+-O2-) excitation and also through the excitation into 8S7/2 → 6IJ intra f-f transition of Gd3+ ion, which significantly all together cover a broad excitation region in 200-420 nm. In addition, in the presence of Yb3+ ions, the emission is also achieved by near infrared excitation (976 nm), through a typical upconversion (UC) process. Thus, the material efficiently behaves as a dual mode emitting phosphor (emission is achieved both through normal fluorescence and through UC process). The conversion efficiency of silicon solar cells is only 15% of terrestrial solar energy for 200-400 nm region and also the sub-band gap energy (in infrared region) is lost as heat; therefore, this kind of dual mode phosphors may be used to overcome the above mentioned incomplete utilization of the solar spectrum and can open realm of new possibilities for energy harvesting.

  5. EU-China Environment Research: Enhancing collaboration through SPRING

    NASA Astrophysics Data System (ADS)

    Bray, Michaela; Han, Dawei

    2013-04-01

    There are huge challenges in both known and potential environmental problems in China and EU. Local geographical and climate conditions vary significantly across the two regions. For example the distribution of water resources is spatially and temporally uneven and often leads to water shortages in some areas, and flooding in others. In addition there is a sharp drop in mineral, oil and gas resources, as well as an increase in the living standard, which is a challenge for sustainable development. China's economy is still growing fast, placing an increased burden on the environment. The EU's economy is more developed with a rich experience in dealing with environmental problems in a fast growing economy. Therefore, it is mutually beneficial for the two sides to collaborate in environmental research. The FP7 funded SPRING project is intended to facilitate better EU-China environmental research cooperation and to create a long-term environment vision with clearly identifiable pathways for the two partners to work together. The project team is composed of five EU partners and five Chinese partners with expertise in water, soil, air, climate change and biodiversity. The project runs from March 2010-Feburary 2013. SPRING has taken a multi-level approach to achieving this, developing foresight and road-mapping studies to manage long term aims and facilitate increased cooperation and exchange for researchers, policy and decision makers and funding bodies. The outcomes of the project include detailed technology survey, success scenario analysis and EU-Horizon research road map with a focus on the research needs between EU and China in the next twenty years.

  6. Epitaxial EuO thin films on GaAs

    SciTech Connect

    Swartz, A. G.; Ciraldo, J.; Wong, J. J. I.; Li Yan; Han Wei; Lin Tao; Shi, J.; Kawakami, R. K.; Mack, S.; Awschalom, D. D.

    2010-09-13

    We demonstrate the epitaxial growth of EuO on GaAs by reactive molecular beam epitaxy. Thin films are grown in an adsorption-controlled regime with the aid of an MgO diffusion barrier. Despite the large lattice mismatch, it is shown that EuO grows well on MgO(001) with excellent magnetic properties. Epitaxy on GaAs is cube-on-cube and longitudinal magneto-optic Kerr effect measurements demonstrate a large Kerr rotation of 0.57 deg., a significant remanent magnetization, and a Curie temperature of 69 K.

  7. The EU-Emotion Stimulus Set: A validation study.

    PubMed

    O'Reilly, Helen; Pigat, Delia; Fridenson, Shimrit; Berggren, Steve; Tal, Shahar; Golan, Ofer; Bölte, Sven; Baron-Cohen, Simon; Lundqvist, Daniel

    2016-06-01

    The EU-Emotion Stimulus Set is a newly developed collection of dynamic multimodal emotion and mental state representations. A total of 20 emotions and mental states are represented through facial expressions, vocal expressions, body gestures and contextual social scenes. This emotion set is portrayed by a multi-ethnic group of child and adult actors. Here we present the validation results, as well as participant ratings of the emotional valence, arousal and intensity of the visual stimuli from this emotion stimulus set. The EU-Emotion Stimulus Set is available for use by the scientific community and the validation data are provided as a supplement available for download. PMID:26424443

  8. Optically induced magnetic polarons in EuTe

    SciTech Connect

    Henriques, A. B.; Galgano, G. D.; Abramof, E.; Rappl, P. H. O.

    2013-12-04

    Direct measurements of the photoinduced magnetization in EuTe, using a two color pump-and-probe technique, are presented. The photoinduced effect was pumped using photons of above-the-bandgap energy, and detected by the Faraday rotation of a probe beam of energy below-the-bandgap. The photoinduced Faraday rotation changes sign, as expected from our model for the optically induced magnetic polaron. The EuTe spin-flop transition at low fields is also detected as a sharp step in the photoinduced Faraday rotation, and its observation provides additional supports for the photoinduced polaron model.

  9. The structuring of GMO release and evaluation in EU law.

    PubMed

    von Kries, Caroline; Winter, Gerd

    2012-04-01

    Genetically modified organisms (GMOs) and their behavior in the environment are complex and can only be assessed if the different components are distinguished. This article examines, how by EU law the real causation processes from the GMO release to various endpoints are dissected, individually analysed and then again viewed in their entirety. In addition, the articles includes, how the intellectual process of assessment is divided into the steps of tiered generation, shared submission and structured evaluation of relevant knowledge. The framework proposed for such an examination allows to identify strengths and weaknesses of GMO risk assessment in the EU. PMID:22121045

  10. Search for Spin Filtering By Electron Tunneling Through Ferromagnetic EuS Barriers in Pbs

    NASA Technical Reports Server (NTRS)

    Figielski, T.; Morawski, A.; Wosinski, T.; Wrotek, S.; Makosa, A.; Lusakowska, E.; Story, T.; Sipatov, A. Yu.; Szczerbakow, A.; Grasza, K.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Perpendicular transport through single- and double-barrier heterostructures consisting of ferromagnetic EuS layers embedded into PbS matrix was investigated. Manifestations of both resonant tunneling and spin filtering through EuS barrier have been observed.

  11. Correlations between mechanical and photoluminescence properties in Eu doped sodium bismuth titanate

    NASA Astrophysics Data System (ADS)

    Prusty, Rajesh K.; Kuruva, Praveena; Ramamurty, U.; Thomas, Tiju

    2013-11-01

    Nanoindentation technique is utilized to examine mechanical property variation in Eu doped Na0.5Bi0.5TiO3 (NBT). Doping levels of Eu in NBT is systematically varied. Dilute doping results in a linear reduction in both modulus and hardness. At higher concentrations, a recovery of the mechanical properties (to undoped NBT values) is observed. These experimental trends mirror variations in the optical emission intensities with Eu concentration. Observed trends are rationalized on the basis of a model, which hypothesizes phase segregation beyond a critical Eu doping level. Such segregation leads to the formation of pure NBT, nano-Eu saturated NBT, and nano-mixed Eu oxides in the microstructure. Pure NBT is optically inactive, while saturated Eu:NBT is a much better emitter when compared to europium oxide. Hence beyond the critical concentration, luminescence signal comes primarily from the saturated Eu:NBT phase. The model presented is supported by nanoindentation, and spectroscopic results.

  12. Effect of Eu substitution on superconductivity in Ba{sub 8−x}Eu{sub x}Al{sub 6}Si{sub 40} clathrates

    SciTech Connect

    Liu, Lihua; Bi, Shanli; Peng, Bailu; Li, Yang

    2015-05-07

    The silicon clathrate superconductor is uncommon as its structure is dominated by strong Si-Si covalent bonds, rather than the metallic bond, that are more typical of traditional superconductors. To understand the influence of large magnetic moment of Eu on superconductivity for type-I clathrates, a series of samples with the chemical formula Ba{sub 8−x}Eu{sub x}Al{sub 6}Si{sub 40} (x = 0, 0.5, 1, and 2) were synthesised in which Eu occupied Ba sites in cage center. With the increase of Eu content, the cubic lattice parameter decreases monotonically signifying continuous shrinkage of the constituting (Ba/Eu)@Si{sub 20} and (Ba/Eu)@Si{sub 24} cages. The temperature dependence of magnetization at low temperature revealed that Ba{sub 8}Al{sub 6}Si{sub 40} is superconductive with transition temperature at T{sub C} = 5.6 K. The substitution of Eu for Ba results in a strong superconductivity suppression; Eu-doping largely decreases the superconducting volume and transition temperature T{sub C}. Eu atoms enter the clathrate lattice and their magnetic moments break paired electrons. The Curie-Weiss temperatures were observed at 3.9, 6.6, and 10.9 K, respectively, for samples with x = 0.5, 1.0, and 2.0. Such ferromagnetic interaction of Eu can destroy superconductivity.

  13. French Antipathy to Turkey's EU Candidacy: The Language Dimension

    ERIC Educational Resources Information Center

    Darby, James

    2009-01-01

    French political leaders have voiced objections to prospective Turkish membership of the European Union (EU), citing material reasons as well as cultural objections involving the uncertain role of a predominantly Islamic society within a European political and economic bloc. Given the importance of the French language as a component of France's…

  14. Policy Learning and Governance of Education Policy in the EU

    ERIC Educational Resources Information Center

    Lange, Bettina; Alexiadou, Nafsika

    2010-01-01

    Open methods for coordinating (OMC) education policies in the EU rely on a number of techniques, one of which is policy learning. This article examines how policy learning and governance transform each other. More specifically, policy-learning in the education OMC becomes differentiated into four distinct learning styles: mutual, competitive,…

  15. The prevalence and costs of obesity in the EU.

    PubMed

    Fry, James; Finley, Willa

    2005-08-01

    The present paper reports on results obtained as part of the economics module of the LIPGENE project. It reviews recent trends in obesity in the fifteen member states of the EU (the member states before enlargement in 2004) and concludes that in 2002 for both adult men and women at least half the fifteen member states of the EU had obesity levels of >20%. In the same year the total direct and indirect annual costs of obesity in the fifteen member states of the EU were 32,800 euro x 10(6). The provision of 'healthy' foods with an adapted lipid profile provides one means of mitigating the impact of obesity. However, there are extra costs associated with the supply of such foods, via additional costs of food ingredients, identity preservation costs for premium-value food products and the penalties caused by the inability to exploit economies of scale. The limited scale of the markets for healthy foods is caused by their high selling prices. Also presented is an analysis of the costs of subsidising, throughout the EU, ingredients that improve the fatty acid profile of beef, eggs, poultry meat and low-fat spreads, so that healthier versions of these products sell at the same price as traditional alternatives. The total costs of such subsidies for these four food products would have been 10 euro x 10(9)/year in 2002, which was 30% of the direct and indirect costs of obesity. PMID:16048669

  16. Technical Report Summary: Metal Chelate, Eu-QCTME

    SciTech Connect

    Richter, James, A.

    2008-05-08

    A novel fluorescent metal complex, Eu-QCTME has shown promise for the early stage detection of cancer. This material has been shown to bind preferentially to xenographic tumors. The study, using HT29 murine xenographic tumors was performed to determine if the chelate preferentially binds to tumor tissue and the potential for an early stage diagnostic test and treatment for epithelial cell cancers.

  17. Modeling EU electricity market competition using the residual supply index

    SciTech Connect

    Swinand, Gregory; Scully, Derek; Ffoulkes, Stuart; Kessler, Brian

    2010-11-15

    An econometric approach to related hourly Residual Supply Index to price-cost margins in the major EU electricity generation markets suggests that market structure, as measured by the RSI, is a significant explanatory factor for markups, even when scarcity and other explanatory variables are included. (author)

  18. Structural phase transitions in EuNbO3 perovskite

    NASA Astrophysics Data System (ADS)

    Kususe, Yoshiro; Yoshida, Suguru; Fujita, Koji; Akamatsu, Hirofumi; Fukuzumi, Masafumi; Murai, Shunsuke; Tanaka, Katsuhisa

    2016-07-01

    The crystal structures of europium niobate, EuNbO3, have been examined over a wide temperature range between 20 and 500 K using synchrotron X-ray diffraction. We have observed two successive structural phase transitions at 360 and 460 K. Below 350 K, EuNbO3 adopts an orthorhombic perovskite structure (space group Imma), which is characterized by NbO6 octahedral tilting about the pseudocubic two-fold axis. The result differs from previous reports in which EuNbO3 was assigned to a cubic aristotype (space group Pm 3 barm) of perovskite at room temperature. At around 360 K, EuNbO3 undergoes a first-order phase transition to a tetragonal symmetry (space group I4/mcm) with the NbO6 octahedral tilting about the pseudocubic four-fold axis. As the temperature is further increased, the I4/mcm tetragonal phase changes into the Pm 3 barm cubic aristotype at 460 K. The tetragonal-to-cubic transformation is characterized as a continuous phase transition.

  19. Biosorption of La, Eu and Yb using Sargassum biomass.

    PubMed

    Diniz, Vivian; Volesky, Bohumil

    2005-01-01

    Biosorption of the lanthanides: Lanthanum (La(3+)), Europium (Eu(3+)) and Ytterbium (Yb(3+)) from single-component and multi-component batch systems using Sargassum polycystum Ca-loaded biomass was studied. The ion exchange sorption mechanism was confirmed by the release of calcium ions from the biomass that matched the total number of metal and protons removed from the solution. The metal binding increased with pH due to the decrease of proton concentration in the system, as they also compete for the binding sites. The maximum metal uptake capacity for pH 3, 4 and 5 ranged approximately between (0.8-0.9) mmol g(-1) for La (0.8-0.9) mmol g(-1) for Eu, and (0.7-0.9) mmol g(-1) for Yb. Biosorption from multi-component mixtures was examined at pH 4 using equimolar initial concentrations of the metals. The metal affinity sequence established was Eu>La>Yb, and the maximum metal uptake obtained was 0.29, 0.41, 0.28 mmol g(-1) for La, Eu and Yb, respectively. PMID:15607182

  20. EU Regulations Impede Market Introduction of GM Forest Trees.

    PubMed

    Custers, René; Bartsch, Detlef; Fladung, Matthias; Nilsson, Ove; Pilate, Gilles; Sweet, Jeremy; Boerjan, Wout

    2016-04-01

    Biotechnology can greatly improve the efficiency of forest tree breeding for the production of biomass, energy, and materials. However, EU regulations impede the market introduction of genetically modified (GM) trees so their socioeconomic and environmental benefits are not realized. European policy makers should concentrate on a science-based regulatory process. PMID:26897457

  1. EuPathDB: The Eukaryotic Pathogen database

    PubMed Central

    Aurrecoechea, Cristina; Barreto, Ana; Brestelli, John; Brunk, Brian P.; Cade, Shon; Doherty, Ryan; Fischer, Steve; Gajria, Bindu; Gao, Xin; Gingle, Alan; Grant, Greg; Harb, Omar S.; Heiges, Mark; Hu, Sufen; Iodice, John; Kissinger, Jessica C.; Kraemer, Eileen T.; Li, Wei; Pinney, Deborah F.; Pitts, Brian; Roos, David S.; Srinivasamoorthy, Ganesh; Stoeckert, Christian J.; Wang, Haiming; Warrenfeltz, Susanne

    2013-01-01

    EuPathDB (http://eupathdb.org) resources include 11 databases supporting eukaryotic pathogen genomic and functional genomic data, isolate data and phylogenomics. EuPathDB resources are built using the same infrastructure and provide a sophisticated search strategy system enabling complex interrogations of underlying data. Recent advances in EuPathDB resources include the design and implementation of a new data loading workflow, a new database supporting Piroplasmida (i.e. Babesia and Theileria), the addition of large amounts of new data and data types and the incorporation of new analysis tools. New data include genome sequences and annotation, strand-specific RNA-seq data, splice junction predictions (based on RNA-seq), phosphoproteomic data, high-throughput phenotyping data, single nucleotide polymorphism data based on high-throughput sequencing (HTS) and expression quantitative trait loci data. New analysis tools enable users to search for DNA motifs and define genes based on their genomic colocation, view results from searches graphically (i.e. genes mapped to chromosomes or isolates displayed on a map) and analyze data from columns in result tables (word cloud and histogram summaries of column content). The manuscript herein describes updates to EuPathDB since the previous report published in NAR in 2010. PMID:23175615

  2. Structure of National Perceptions of Social Needs across EU Countries

    ERIC Educational Resources Information Center

    Dickes, Paul; Fusco, Alessio; Marlier, Eric

    2010-01-01

    Back in 1975, the European Union (EU) Council of Ministers defined the poor as "individuals or families whose resources are so small as to exclude them from the minimum acceptable way of life of the Member State in which they live". This widely quoted definition leaves room for discussion about what can be considered a "minimum acceptable way of…

  3. Overcoming Challenges Facing Advanced Therapies in the EU Market.

    PubMed

    Abou-El-Enein, Mohamed; Elsanhoury, Ahmed; Reinke, Petra

    2016-09-01

    While advanced therapy medicinal products offer great clinical promise, most EU-approved products have not achieved satisfactory commercial performance. Here we highlight a number of issues that prevent current products from obtaining commercial success and pitfalls that developers must overcome in future product development. PMID:27588746

  4. Lifelong Learning in the EU: Changing Conceptualisations, Actors, and Policies

    ERIC Educational Resources Information Center

    Volles, Nina

    2016-01-01

    This paper explores the changing conceptualisations, actors, and policies of lifelong learning (LLL) in the European Union (EU) from the time the topic first emerged and was promoted by international organisations in the 1960s. The author uses Kingdon's Multiple Streams Framework to analyse how the LLL discourse became an important part of the EU…

  5. Magnetic and Fermi Surface Properties of EuGa4

    NASA Astrophysics Data System (ADS)

    Nakamura, Ai; Hiranaka, Yuichi; Hedo, Masato; Nakama, Takao; Miura, Yasunao; Tsutsumi, Hiroki; Mori, Akinobu; Ishida, Kazuhiro; Mitamura, Katsuya; Hirose, Yusuke; Sugiyama, Kiyohiro; Honda, Fuminori; Settai, Rikio; Takeuchi, Tetsuya; Hagiwara, Masayuki; Matsuda, Tatsuma D.; Yamamoto, Etsuji; Haga, Yoshinori; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Harima, Hisatomo; Ōnuki, Yoshichika

    2013-10-01

    We grew a high-quality single crystal EuGa4 with the tetragonal structure by the Ga self-flux method, and measured the electrical resistivity, magnetic susceptibility, high-field magnetization, specific heat, thermoelectric power and de Haas--van Alphen (dHvA) effect, together with the electrical resistivity and thermoelectric power under pressure. EuGa4 is found to be a Eu-divalent compound without anisotropy of the magnetic susceptibility in the paramagnetic state and to reveal the same magnetization curve between H \\parallel [100] and [001] in the antiferromagnetic state, where the antiferromagnetic easy-axis is oriented along the [100] direction below a Néel temperature TN=16.5 K. The magnetization curve is discussed on the basis of a simple two-sublattice model. The Fermi surface in the paramagnetic state was clarified from the results of a dHvA experiment for EuGa4 and an energy band calculation for a non-4f reference compound SrGa4, which consists of a small ellipsoidal hole--Fermi surface and a compensated cube-like electron--Fermi surface with vacant space in center. We observed an anomaly in the temperature dependence of the electrical resistivity and thermoelectric power at TCDW=150 K under 2 GPa. This might correspond to an emergence of the charge density wave (CDW). The similar phenomenon was also observed in EuAl4 at ambient pressure. We discussed the CDW phenomenon on the basis of the present peculiar Fermi surfaces.

  6. Anisotropic Optical-Response of Eu-doped Yttrium Orthosilicate

    NASA Technical Reports Server (NTRS)

    Liu, Huimin; Santiago, Miguel; Jia, Weiyi; Zhang, Shoudu

    1998-01-01

    Eu-doped yttrium orthosilicate (Eu(3+) : Y2SiO5) had been a subject being investigated for coherent time-domain optical memory and information processing applications since its ultraslow optical dephasing was discovered several years ago. In this crystal the weakly allowed (7)F0 - (5)D0 transition of europium ions exhibits a sufficient long dephasing time and no spectral difli.usion on a time scale of several hours at low temperature, thus an information pattern or data can be stored as a population grating in the ground state hyperfine levels. On the other hand, the study on photon-echo relaxation shows that the dephasing time T2 of Eu (3+) and other rare-earth ions doped YAG, YAlO3 strongly depends on the intensity of the excitation pulses. In Eu (3+) :YAlO3, an exponential decay of photon-echo with T2 = 53 microseconds if the excitation pulses are weak (5 vJ/pulse) was observed. However, when the excitation pulses are strong (80 pJ/pulse) they observed a much shortened T2 with a highly nonexponential decay pattern. The conclusion they derived is that the intensity-dependent dephasing rate effects are quite general, and it depends on how much the excitation intensity varies. In this paper we use transient grating formation technique showing that a temporal lattice distortion may only occur along crystal c axis, caused by EU (3+) excitation. At high excitation level the produced exciton in conduction band may also couple to the dynamical lattice relaxation process, giving rise to an apparently much shortened dephasing time.

  7. Hyper-stable organo-EuIII luminophore under high temperature for photo-industrial application

    NASA Astrophysics Data System (ADS)

    Nakajima, Ayako; Nakanishi, Takayuki; Kitagawa, Yuichi; Seki, Tomohiro; Ito, Hajime; Fushimi, Koji; Hasegawa, Yasuchika

    2016-04-01

    Novel organo-EuIII luminophores, Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y (hfa: hexafluoroacetylacetonate, CPO: 4-carboxyphenyl diphenyl phosphine oxide, TCPO: 4,4‧,4″-tricarboxyphenyl phosphine oxide), were synthesized by the complexation of EuIII ions with hfa moieties and CPO or TCPO ligands. The thermal and luminescent stabilities of the luminophores are extremely high. The decomposition temperature of Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y were determined as 200 and 450 °C, respectively. The luminescence of Eu(hfa)x(TCPO)y under UV light irradiation was observed even at a high temperature, 400 °C. The luminescent properties of Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y were estimated from emission spectra, quantum yields and lifetime measurements. The energy transfer efficiency from hfa moieties to EuIII ions in Eu(hfa)x(TCPO)y was 59%. The photosensitized luminescence of hyper-stable Eu(hfa)x(TCPO)y at 400 °C is demonstrated for future photonic applications.

  8. Teaching Citizenship: What if the EU Is Part of the Solution and Not the Problem?

    ERIC Educational Resources Information Center

    Lödén, Hans; McCallion, Malin Stegmann; Wall, Peter

    2014-01-01

    We propose that the European Union (EU) should be used in citizenship education as a possible vehicle for citizens' influence on issues outside the reach of the nation-state. Citizenship education thus ought to include the EU as an arena for political action and relevant "EU knowledge" ought to be part of the curriculum. Concepts…

  9. Optical and spectroscopic properties of Eu2O3 doped CaBAl glasses

    NASA Astrophysics Data System (ADS)

    Melo, G. H. A.; Dias, J. D. M.; Lodi, T. A.; Barboza, M. J.; Pedrochi, F.; Steimacher, A.

    2016-04-01

    Eu2O3 doped CaBAL glasses (x Eu2O3) - (25-x) CaO - (50) B2O3 - (15) Al2O3 - (10) CaF2 (x = 0, 5, 1, 2, 3, 4, 5, 10 wt%) were prepared by using conventional melt-quenching and studied by means of density measurements, refractive index, optical absorption, luminescence and radiative lifetime. The results are discussed in terms of Eu2O3 content. The incorporation of Eu2O3 leads to an increase in the electronic polarizability and the refractive index. A linear increase with Eu2O3 content was observed in the optical absorption coefficient at 394 nm. The luminescence spectra present typical Eu3+ emission and do not present quenching up to 10 wt%. The luminescence ratio R/O I(5D0 → 7F2)/I(5D0 → 7F1) presents an increase with Eu2O3 doping; it indicates a reduction in local symmetry around the Eu3+ ions. The CIE 1931 diagram presents a red shift and an increase of color purity with Eu2O3 addition. The luminescence as a function of temperature shows an increase of 25% in the luminescence intensity for the Eu0.5 sample, at 592 nm. The radiative lifetime at 614 nm shows an exponential decay due to the reduction of the interionic distance Eu3+ - Eu3+ and the increase of the ion-ion interaction.

  10. Hyper-stable organo-EuIII luminophore under high temperature for photo-industrial application

    PubMed Central

    Nakajima, Ayako; Nakanishi, Takayuki; Kitagawa, Yuichi; Seki, Tomohiro; Ito, Hajime; Fushimi, Koji; Hasegawa, Yasuchika

    2016-01-01

    Novel organo-EuIII luminophores, Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y (hfa: hexafluoroacetylacetonate, CPO: 4-carboxyphenyl diphenyl phosphine oxide, TCPO: 4,4′,4″-tricarboxyphenyl phosphine oxide), were synthesized by the complexation of EuIII ions with hfa moieties and CPO or TCPO ligands. The thermal and luminescent stabilities of the luminophores are extremely high. The decomposition temperature of Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y were determined as 200 and 450 °C, respectively. The luminescence of Eu(hfa)x(TCPO)y under UV light irradiation was observed even at a high temperature, 400 °C. The luminescent properties of Eu(hfa)x(CPO)y and Eu(hfa)x(TCPO)y were estimated from emission spectra, quantum yields and lifetime measurements. The energy transfer efficiency from hfa moieties to EuIII ions in Eu(hfa)x(TCPO)y was 59%. The photosensitized luminescence of hyper-stable Eu(hfa)x(TCPO)y at 400 °C is demonstrated for future photonic applications. PMID:27074731

  11. Oxygen off-stoichiometry and phase separation in EuO thin films

    SciTech Connect

    Altendorf, S. G.; Efimenko, A.; Oliana, V.; Kierspel, H.; Rata, A. D.; Tjeng, L. H.

    2011-10-15

    We report on our study on the influence of the growth conditions on the europium/oxygen stoichiometry, morphology, magnetic properties, and electrical conductivity of EuO thin films. SQUID magnetometry and x-ray photoelectron spectroscopy were utilized as complementary techniques to determine the oxygen content of EuO{sub 1{+-}x} thin films grown by molecular beam epitaxy with and without the employment of the so-called Eu distillation process. We found indications for phase separation to occur in Eu-rich as well as in over-oxidized EuO for films grown at substrate temperatures below the Eu distillation temperature. Only a fraction of the excess Eu contributes to the metal-insulator transition in Eu-rich films grown under these conditions. We also observed that the surfaces of these films were ill defined and may even contain more Eu excess than the film average. Only EuO films grown under distillation conditions are guaranteed to have the same magnetic and electrical properties as stoichiometric bulk EuO, and to have surfaces with the proper Eu/O stoichiometry and electronic structure.

  12. EU Rural Development Policy in the New Member States: Promoting Multifunctionality?

    ERIC Educational Resources Information Center

    Ramniceanu, Irina; Ackrill, Robert

    2007-01-01

    European Union (EU) enlargement has seen 10 new member states (NMS) adopt the full range of EU policies. Within this, the rural development arm of the Common Agricultural Policy offers particular points of interest. Member states chose from an extensive list of policy measures developed within the EU15 and intended, in particular, to…

  13. The EU as a Norm Entrepreneur: The Case of Lifelong Learning

    ERIC Educational Resources Information Center

    Kleibrink, Alexander

    2011-01-01

    The EU has become one of the most prominent promoters of lifelong learning policies. Inside the European single market, EU member states have strong incentives to adopt similar approaches to lifelong learning and recognition of educational attainments in order to foster labour mobility. More surprisingly, countries neighbouring the EU also develop…

  14. Conjunctive Cohesion in English Language EU Documents--A Corpus-Based Analysis and Its Implications

    ERIC Educational Resources Information Center

    Trebits, Anna

    2009-01-01

    This paper reports the findings of a study which forms part of a larger-scale research project investigating the use of English in the documents of the European Union (EU). The documents of the EU show various features of texts written for legal, business and other specific purposes. Moreover, the translation services of the EU institutions often…

  15. Growth of EuO/Si and EuO/SrO/Si heteroepitaxial structures by molecular-beam epitaxy

    SciTech Connect

    Teterin, P. E. Averyanov, D. V.; Sadofyev, Yu. G. Parfenov, O. E.; Likhachev, I. A.; Storchak, V. G.

    2015-01-15

    Epitaxial EuO thin films with thickness up to 60 nm have been grown by molecular beam epitaxy both on SrO sublayers and directly on Si (001) substrates. Crystal structure has been controlled in situ by reflection high energy electron diffraction. Ex situ studies by X-ray diffraction and Rutherford backscattering have confirmed high crystalline quality of the films.

  16. Accelerators for society: succession of European infrastructural projects: CARE, EuCARD, TIARA, EuCARD2

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2013-10-01

    Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the realization of CARE (Coordinated Accelerator R&D), EuCARD (European Coordination of Accelerator R&D) and during the national annual review meeting of the TIARA - Test Infrastructure of European Research Area in Accelerator R&D. The European projects on accelerator technology started in 2003 with CARE. TIARA is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparatory phase) is an European infrastructural project run by this Consortium and realized inside EU-FP7. The paper presents a general overview of CARE, EuCARD and especially TIARA activities, with an introduction containing a portrait of contemporary accelerator technology and a digest of its applications in modern society. CARE, EuCARD and TIARA activities integrated the European accelerator community in a very effective way. These projects are expected very much to be continued.

  17. Giant magnetocaloric effect in magnetically frustrated EuHo2O4 and EuDy2O4 compounds

    NASA Astrophysics Data System (ADS)

    Midya, A.; Khan, N.; Bhoi, D.; Mandal, P.

    2012-09-01

    We have investigated the magnetic and magnetocaloric properties of EuHo2O4 and EuDy2O4 by magnetization and heat capacity measurements down to 2 K. These compounds undergo a field-induced antiferromagnetic to ferromagnetic transition and exhibit a huge entropy change. For a field change of 0-8 T, the maximum magnetic entropy and adiabatic temperature changes are 30 (25) J kg-1 K-1 and 12.7 (16) K, respectively, and the corresponding value of refrigerant capacity is 540 (415) J kg-1 for EuHo2O4 (EuDy2O4). These magnetocaloric parameters also remain large down to lowest temperature measured and are even larger than that for some of the potential magnetic refrigerants reported in the same temperature range. Moreover, these materials are highly insulating and exhibit no thermal and field hysteresis, fulfilling the necessary conditions for a good magnetic refrigerant in the low-temperature region.

  18. Boron induced change of the Eu valence state in EuPd3Bx (0≤x≤0.53) : A theoretical and experimental study

    NASA Astrophysics Data System (ADS)

    Gumeniuk, R.; Schmitt, M.; Loison, C.; Carrillo-Cabrera, W.; Burkhardt, U.; Auffermann, G.; Schmidt, M.; Schnelle, W.; Geibel, C.; Leithe-Jasper, A.; Rosner, H.

    2010-12-01

    A valence instability of Eu in EuPd3Bx (0≤x≤1) was discussed controversially in the past. In a joint theoretical and experimental study we investigate a large series of EuPd3Bx and GdPd3Bx compounds. Characterization by x-ray diffraction, metallography, energy-, and wavelength-dispersive x-ray spectroscopy as well as chemical analysis determine an existence range of EuPd3Bx up to x≤0.53 and x≤0.42 for the GdPd3Bx compounds, respectively. Our density-functional-based electronic structure calculation predict a valence change in EuPd3Bx above xcDFT=0.19±0.02 from a nonmagnetic Eu3+ state into a magnetic Eu2+ state which is reflected in a discontinuity of the lattice parameter. In contrast, the related Gd compounds with a stable Gd3+ state exhibit an almost linear behavior of the lattice parameter following Vegard’s law. Consistent with the calculations, the x-ray diffraction data show a kink in the lattice parameter for EuPd3Bx at xcXRD=0.22±0.02 . X-ray absorption spectroscopy measurements assign this kink to a transition into a heterogeneous mixed valence state for Eu with a critical B content xcXAS=0.22±0.03 . The observed change in the mean Eu valence from Eu3+ (x≤0.2) toward Eu2.5+ (x=0.5) is supported by magnetic susceptibility and specific-heat data.

  19. Eu2+ concentration effects in KCa0.8Sr0.2I3:Eu2+: A novel high-performance scintillator

    NASA Astrophysics Data System (ADS)

    Wu, Yuntao; Zhuravleva, Mariya; Lindsey, Adam C.; Koschan, Merry; Melcher, Charles L.

    2016-06-01

    We report here the effect of Eu2+ concentration in KCa0.8Sr0.2I3:Eu2+ single crystal scintillators. KCa0.8Sr0.2I3:Eu2+ single crystals doped with 0.5, 1, 3, 5, and 7 mol% Eu2+ were grown by the Bridgman method. The effects of varying Eu2+concentration and crystal volume on the scintillation properties, including light yield, energy resolution, nonproportionality, scintillation decay time and afterglow level, were systematically investigated. For 5 mm×5 mm×5 mm samples, the best light yield of 86,000±4000 photons/MeV was achieved with a content of 5 mol% Eu2+; its energy resolution of 2.5% at 662 keV was comparable to that of LaBr3:Ce3+ and SrI2:Eu2+. With larger samples of about 2.2 cm3, the best performances achieved were for 3 mol% Eu2+ concentration, i.e. a light yield of 76,000±4000 photons/MeV and an energy resolution of 3% at 662 keV. A direct correlation between nonproportionality and Eu2+ concentration was found. A continuous lengthening of scintillation decay time and x-ray induced afterglow level with increasing Eu2+ concentration was observed. The self-absorption effect was evaluated by using the Stokes shift and the temperature dependence of the photoluminescence decay (PL) of the Eu2+ centers. The sample with the highest dopant concentration had more severe temperature quenching of the Eu2+5d-4f emission than the sample with the lowest dopant concentration, which could be ascribed to the thermally activated concentration quenching.

  20. Phase equilibrium and intermediate phases in the Eu-Sb system

    SciTech Connect

    Abdusalyamova, M.N.

    2011-10-15

    Rapid heating rate thermal analysis, X-ray diffraction, fluorescence spectrometry, and differential dissolution method were used to study the high-temperature phase equilibrium in the Eu-Sb system within the composition range between 37 and 96 at% Sb. The techniques were effective in determination of the vapor-solid-liquid equilibrium since intermediate phases except Eu{sub 4}Sb{sub 3} evaporated incongruently after melting. A thermal procedure was developed to determine the liquidus and solidus lines of the T-x diagram. Six stable phases were identified: two phases, EuSb{sub 2} and Eu{sub 4}Sb{sub 3}, melt congruently at 1045{+-}10 deg. C and 1600{+-}15 deg. C, the Eu{sub 2}Sb{sub 3}, Eu{sub 11}Sb{sub 10}, Eu{sub 5}Sb{sub 4}, and Eu{sub 5}Sb{sub 3} phases melt incongruently at 850{+-}8 deg. C, 950{+-}10 deg. C, 1350{+-}15 deg. C, and 1445{+-}15 deg. C, respectively. The exact composition shifting of Sb-rich decomposable phases towards Eu{sub 4}Sb{sub 3}, the most refractory compound, was determined. The topology of the Eu-Sb phase diagram was considered together with that of the Yb-Sb system. - Graphical abstract: The high-temperature range of the T-x phase diagram for the Eu-Sb system. Highlights: > The phase relations in the Eu-Sb system were studied over a large composition and temperature scale. > The liquidus and solidus lines of the T-x diagram were well established using effective techniques. > In the system, six binary phases are stable and they melt incongruently except EuSb{sub 2} and Eu{sub 4}Sb{sub 3}. > Incongruent evaporation was found to be typical of all the phases besides Eu{sub 4}Sb{sub 3}.

  1. Enhanced photo/electroluminescence properties of Eu-doped GaN through optimization of the growth temperature and Eu related defect environment

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Mitchell, B.; Timmerman, D.; Uedono, A.; Koizumi, A.; Fujiwara, Y.

    2016-05-01

    The influence of growth temperature on the surface morphology and luminescence properties of Eu-doped GaN layers grown by organometallic vapor phase epitaxy was investigated. By using a Eu source that does not contain oxygen in its molecular structure, and varying the growth temperature, the local defect environment around the Eu3+ ions was manipulated, yielding a higher emission intensity from the Eu3+ ions and a smoother sample surface. The optimal growth temperature was determined to be 960 °C and was used to fabricate a GaN-based red light-emitting diode with a significantly higher output power.

  2. Effect of annealing temperature on the structural reorganization of Eu3+ optical centers in Al2O3-Eu2O3-BiOF gel films

    NASA Astrophysics Data System (ADS)

    Malashkevich, G. E.; Kornienko, A. A.; Dunina, E. B.; Prusova, I. V.; Shevchenko, G. P.; Bokshits, Yu. V.

    2007-06-01

    The dependence of the structural reorganization of Eu3+ optical centers in Al2O3-Eu2O3-BiOF films on the annealing temperature has been investigated. It is shown by the methods of crystal field theory and computer simulation that the increase in the annealing temperature from 700 to 1100 °C leads to removal of bismuth from Eu-O-Bi complex centers with the C 3V symmetry in the Al2O3 structure and the change in symmetry from D 3 to O h for a large fraction of EuAlO3 centers.

  3. Synthesis and properties of ZnS-EuS films grown from volatile complex compounds

    SciTech Connect

    Bessergenev, V.G.; Ivanova, E.N.; Kovalevskaya, Y.A.

    1997-10-01

    Deposition and characterization of films of ZnS, EuS and ZnS:Eu are described. The films have been prepared by chemical vapor deposition using new volatile complex compounds, dithiocarbamates of Zn and Eu, as precursors. Characterization includes X-ray diffraction, chemical analysis of the film composition, Raman spectroscopy, ellipsometry, and spectrophotometry. The spatial chemical homogeneity of the films has been determined using a recently developed method of differential dissolution and found to be uniform. Doping of ZnS by Eu with dopant concentration up to 0.3 at.% has been achieved. Effects of Eu doping on structural and optical properties of the films are presented.

  4. Synthesis and Photoluminescent Properties of Eu²⁺-Doped BaSiF₆ Nanoparticles.

    PubMed

    Zhao, Xin; Hua, Ruinian; Zhang, Wei; Zhao, Jun; Tang, Dongxin; Sun, Zhengang

    2016-01-01

    By adjusting the molar ratio of oleic acid (OA), oleylamine (OM), and 1-octadecene (OD) ligands in reaction solution, Eu²⁺-doped BaSiF₆ nanoparticles were synthesized using a thermal decomposition synthesis route. Eu²⁺ ions have been successfully doped into BaSiF₆ host lattice and strong 4f-4f line emission of the Eu²⁺ in BaSiF₆ matrix is observed. Meanwhile, the photoluminescent (PL) properties of BaSiF₆:Eu²⁺ nanoparticles doping Eu²⁺ ions at different concentrations were also studied. PMID:27398531

  5. Luminescence properties of ZnS:Cu, Eu semiconductor nanocrystals synthesized by a hydrothermal process

    NASA Astrophysics Data System (ADS)

    Xin, Mei; Hu, Li-Zhong

    2013-08-01

    ZnS:Cu, Eu nanocrystals with an average diameter of ~ 80 nm are synthesized using a hydrothermal approach at 200 °C. The photoluminescence (PL) properties of the ZnS:Cu, Eu nanocrystals before and after annealing, as well as the doping form of Eu, are studied. The as-synthesized samples are characterized by X-ray diffraction, scanning electron microscopy, inductively coupled plasma-atomic emission spectrometry, and the excitation and emission spectra (PL). The results show that both Cu and Eu are indeed incorporated into the ZnS matrix. Compared with the PL spectrum of the Cu mono-doped sample, the PL emission intensity of the Cu and Eu-codoped sample increases and a peak appears at 516 nm, indicating that Eu3+ ions, which act as an impurity compensator and activator, are incorporated into the ZnS matrix, forming a donor level. Compared with the unannealed sample, the annealed one has an increased PL emission intensity and the peak position has a blue shift of 56 nm from 516 nm to 460 nm, which means that Eu3+ ions reduce to Eu2+ ions, thereby leading to the appearance of Eu2+ characteristic emission and generating effective host-to-Eu2+ energy transfer. The results indicate the potential applications of ZnS:Cu, Eu nanoparticles in optoelectronic devices.

  6. Strong blue light emission from Eu-doped SiOC prepared by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lin, Zhenxu; Guo, Yanqing; Wang, Xiang; Song, Chao; Song, Jie; Zhang, Yi; Huang, Rui

    2015-08-01

    The Eu-doped SiOC films were prepared by magnetron sputtering technique at a low temperature of 250°C. The effects of the Eu2O3 deposited power and post-thermal annealing temperature on the PL characteristics of the Eu-doped SiOC films were investigated. It is found that the photoluminescence intensity could be enhanced by more than tenfold by increasing the Eu2O3 deposited power from 20W to 80W. Furthermore, very bright blue light emission can be clearly observed with the naked eye in a bright room for the Eu-doped SiOC films prepared at a Eu2O3 deposited power of 80 W. The improved PL intensity is attributed to the increasing number density of europium silicate clusters as a result of the increasing Eu2O3 deposited power as well as high annealing temperatures.

  7. Preparation and photoluminescence properties of red-emitting SrMoO4:Eu nanophosphor microcapsules

    NASA Astrophysics Data System (ADS)

    Cho, Young-Sik; Huh, Young-Duk

    2015-11-01

    We prepared SrMoO4:Eu nanophosphors with a mean size of 5 nm from Sr-oleate and Eu-oleate complexes in a hexane layer and an aqueous (NH4)6Mo7O24 solution by performing solvothermal reactions. A bright redemitting SrMoO4:Eu suspension was obtained in hexane solution. The SrMoO4:Eu suspension was found to be sufficiently hydrophobic for the formation of SrMoO4:Eu phosphor microcapsules. Melamine-formaldehyde polymers were used to prepare the SrMoO4:Eu phosphor microcapsules. We tested the SrMoO4:Eu phosphor microcapsules in a wearable outdoor application. [Figure not available: see fulltext.

  8. Superconductivity in Fe-Based Compound EuAFe4As4 (A = Rb and Cs)

    NASA Astrophysics Data System (ADS)

    Kawashima, Kenji; Kinjo, Tatsuya; Nishio, Taichiro; Ishida, Shigeyuki; Fujihisa, Hiroshi; Gotoh, Yoshito; Kihou, Kunihiro; Eisaki, Hiroshi; Yoshida, Yoshiyuki; Iyo, Akira

    2016-06-01

    We report the discovery of a novel Fe-based superconductor EuAFe4As4 (A = Rb, Cs) and describe its superconducting properties. EuAFe4As4 has a tetragonal unit cell with a P4/mmm (No. 123) space group, indicating that this material is an 1144-type compound. The magnetic susceptibility and electrical resistivity indicate superconducting transitions at approximately 36 and 35 K for EuRbFe4As4 and EuCsFe4As4, respectively. Moreover, an anomalous magnetic transition appears at approximately 15 K, suggesting the coexistence of superconductivity and a magnetic ordered state formed by the Eu2+ ions. The determined upper critical magnetic fields and coherence lengths are approximately 920 kOe and 1.8 nm for EuRbFe4As4 and 875 kOe and 1.9 nm for EuCsFe4As4, respectively.

  9. Financial effects of pharmaceutical price regulation on R&D spending by EU versus US firms.

    PubMed

    Golec, Joseph; Vernon, John A

    2010-01-01

    EU countries closely regulate pharmaceutical prices, whereas the US does not. This paper shows how price constraints affect the profitability, stock returns and R&D spending of EU and US firms. Compared with EU firms, US firms are more profitable, earn higher stock returns and spend more on R&D. We tested the relationship between price regulation and R&D spending, and estimated the costs of tight EU price regulation. Although results show that EU consumers enjoyed much lower pharmaceutical price inflation, we estimated that price controls cost EU firms 46 fewer new medicines and 1680 fewer research jobs during our 19-year sample period. Had the US used controls similar to those used in the EU, we estimate it would have led to 117 fewer new medicines and 4368 fewer research jobs in the US. PMID:20617857

  10. Thermophysical characteristics of EuF2.136 crystal

    NASA Astrophysics Data System (ADS)

    Popov, P. A.; Moiseev, N. V.; Karimov, D. N.; Sorokin, N. I.; Sulyanova, E. A.; Sobolev, B. P.

    2015-09-01

    Single crystals of EuF2.136 solid solution with a f luorite-type structure (sp. gr. , a = 5.82171(5) Å) have been grown by the Bridgeman method from a melt. Their thermal conductivity k( T) in the temperature range of 50-300 K and heat capacity С Р ( T) at 63-300 K have been studied experimentally for the first time. At T = 300 K the thermophysical characteristics are as follows: thermal conductivity k = 2.13 W/(m K), heat capacity С Р = 73 J/(mol K), and phonon mean free path l ≈ 11 Å. The temperature dependences of entropy S( T), enthalpy H( T), and phonon mean free path l( T) in EuF2.136 crystal are determined.

  11. Cultural circumcision in EU public hospitals--an ethical discussion.

    PubMed

    Brusa, Margherita; Barilan, Y Michael

    2009-10-01

    The paper explores the ethical aspects of introducing cultural circumcision of children into the EU public health system. We reject commonplace arguments against circumcision: considerations of good medical practice, justice, bodily integrity, autonomy and the analogy from female genital mutilation. From the unique structure of patient-medicine interaction, we argue that the incorporation of cultural circumcision into EU public health services is a kind of medicalization, which does not fit the ethos of universal healthcare. However, we support a utilitarian argument that finds hospital based circumcision safer than non-medicalized alternatives. The argument concerning medicalization and the utilitarian argument both rely on preliminary empirical data, which depend on future validation PMID:19076127

  12. Early market access of cancer drugs in the EU.

    PubMed

    Martinalbo, J; Bowen, D; Camarero, J; Chapelin, M; Démolis, P; Foggi, P; Jonsson, B; Llinares, J; Moreau, A; O'Connor, D; Oliveira, J; Vamvakas, S; Pignatti, F

    2016-01-01

    Patient access to new cancer drugs in the EU involves centralised licensing decisions by regulators as well as reimbursement recommendations in the context of national healthcare systems. Differences in assessment criteria and evidence requirements may result in divergent decisions at central and national levels, ultimately compromising effective access to patients. Early access decisions are particularly challenging due to the limited clinical evidence available to conclude on the benefit-risk and relative (cost-) effectiveness of new high-priced cancer drugs. We describe mechanisms to accelerate approval of promising anticancer drugs that fulfil an unmet medical need, review the experience from the European Medicines Agency, compare timelines and outcomes of reimbursement decisions in major EU markets, and discuss shortcomings of the current system, ongoing initiatives, and future steps to facilitate effective early access. PMID:26487583

  13. Possible magnetic structures of EuZrO3

    NASA Astrophysics Data System (ADS)

    Hu, Ai-Yuan; Qin, Guo-Ping; Wu, Zhi-Min; Cui, Yu-Ting

    2015-06-01

    A comprehensive research of the antiferromagnetic (AFM) structures of perovskite-type EuZrO3 is carried out by use of the double-time Green’s function. Two possible types of AFM configurations are considered, and theoretical results are compared with experimental results to extract the values of parameters J1, J2, and D. The obtained exchanges are employed to calculate the magnetic susceptibility, which is then in turn compared with the experimental one. Therefore, we think that the magnetic structure of EuZrO3 may be an isotropic G-type structure or an anisotropic A-type structure. Project supported by the National Natural Science Foundation of China (Grant Nos. 11404046, 11347217, and 61201119), the Basic Research Foundation of Chongqing Education Committee, China (Grant No. KJ130615), and the Chongqing Science & Technology Committee, China (Grant Nos. cstc2014jcyjA50013 and cstc2013jjB50001).

  14. Adoption of the EU SEA Directive in Turkey

    SciTech Connect

    Unalan, Dilek; Cowell, Richard

    2009-07-15

    This paper analyses the adoption of the EU Strategic Environmental Assessment Directive (2001/42/EC) in Turkey as part of a programme of environmental policy harmonisation for EU accession, to explore the extent to which this is driving wider shifts in modes of environmental governance. To do this, rather than simply assess compliance with Directive in narrow, formal, statutory terms, we use Jaenicke and Weidner's concept of capacity building, which focuses on the constraints facing societal action to promote sustainable development. Despite the resources invested in pre-accession training and pilot SEA projects, Turkey's adoption of the Directive is still likely to be affected by the centralised nature of the bureaucracy (affecting the scope for sectoral integration), its politicised nature (interrupting the accumulation of policy learning), the limited capacity of civil society and environmental organisations to engage with the process, and the political dominance of economic development objectives.

  15. Seeking the optimal LaTaO{sub 4}:Eu phosphor

    SciTech Connect

    Bleier, Grant C.; Nyman, May; Rohwer, Lauren E.S.; Rodriguez, Mark A.

    2011-12-15

    Lanthanum orthotantalate, LaTaO{sub 4}, is an excellent host lattice for rare-earth luminescent ions such as Eu{sup 3+} for red emission. However, there are multiple RETaO{sub 4} (RE=rare earth) polymorphs, and the stability of these is controlled predominantly by the RE-radius. Thus it is difficult to obtain a pure phase of LaTaO{sub 4}:Eu as Eu concentration and consequently the RE radius is varied. We recently reported a 'soft-chemical' route that allows crystallization of pure-phase LaTaO{sub 4}:Eu at temperatures as low as 800 Degree-Sign C. In the current report, we investigate polymorph evolution and Eu emission as a function of Eu concentration and annealing temperature. We obtain a maximum quantum yield (QY) of 83% at the highest Eu substitution (25%) for which the low temperature orthorhombic (Pbca) polymorph is stable. Therefore, QY is not limited necessarily by concentration quenching; rather it is limited by polymorph stability as the RE-radius decreases with increasing Eu substitution. - Graphical Abstract: Eu-substituted lanthanum orthotantalates, LaTaO{sub 4}:Eu, are excellent red phosphors. They exhibit up to 83% quantum-yield emission under blue light excitation, optimized through both 'soft chemical processing' and polymorph purity. Highlights: Black-Right-Pointing-Pointer LaTaO{sub 4}:Eu phosphors were synthesized via 'soft-chemical' and solid-state routes. Black-Right-Pointing-Pointer Quantum-yield of Eu emission depends on host polymorph, which changes with La:Eu ratio. Black-Right-Pointing-Pointer Polymorph with optimal Eu-emission is only obtained by 'soft-chemistry'.

  16. EuTZn (T=Pd, Pt, Au) with TiNiSi-type structure-Magnetic properties and {sup 151}Eu Moessbauer spectroscopy

    SciTech Connect

    Mishra, Trinath; Hermes, Wilfried; Harmening, Thomas; Eul, Matthias; Poettgen, Rainer

    2009-09-15

    The europium compounds EuTZn (T=Pd, Pt, Au) were synthesized from the elements in sealed tantalum tubes in an induction furnace. These intermetallics crystallize with the orthorhombic TiNiSi-type structure, space group Pnma. The structures were investigated by X-ray diffraction on powders and single crystals: a=732.3(2), b=448.5(2), c=787.7(2) pm, R{sub 1}/wR{sub 2}=0.0400/0.0594, 565 F{sup 2} values for EuPdZn, a=727.8(3), b=443.7(1), c=781.7(3) pm, R{sub 1}/wR{sub 2}=0.0605/0.0866, 573 F{sup 2} values for EuPtZn, and a=747.4(2), b=465.8(2), c=789.1(4) pm, R{sub 1}/wR{sub 2}=0.0351/0.0590, 658 F{sup 2} values for EuAuZn, with 20 variables per refinement. Together the T and zinc atoms build up three-dimensional [TZn] networks with short T-Zn distances. The EuTZn compounds show Curie-Weiss behavior in the temperature range from 75 to 300 K with mu{sub eff}=7.97(1), 7.70(1), and 7.94(1) mu{sub B}/Eu atom and theta{sub P}=18.6(1), 34.9(1), and 55.5(1) K for T=Pd, Pt, and Au, respectively, indicating divalent europium. Antiferromagntic ordering was detected at 15.1(3) K for EuPdZn and canted ferromagnetic ordering at 21.2(3) and 51.1(3) K for EuPtZn and EuAuZn. {sup 151}Eu Moessbauer spectroscopic measurements confirm the divalent nature of the europium atoms by isomer shift values ranging from -8.22(8) (EuPtZn) to -9.23(2) mm/s (EuAuZn). At 4.2 K full magnetic hyperfine field splitting is observed in all three compounds due to magnetic ordering of the europium magnetic moments. - Graphical abstract: Europium coordination in EuPdZn, EuPtZn, and EuAuZn.

  17. THE POLITICS OF RISK AND EU GOVERNANCE OF HUMAN MATERIAL

    PubMed Central

    Farrel, Anne-Maree

    2012-01-01

    This paper examines the politics of EU risk governance in relation to human material. It is argued that the political context has informed the way in which risks in relation to various types of human material have come to be defined as policy problems at EU level. In turn, this has influenced the design and/or persistence of institutional arrangements to manage such problems. It is further argued that this political context has resulted in a significant level of disconnection in risk governance in the area. This has happened in two ways. First, there has been a growing level of disconnection between institutional and stakeholder demands for a more expansive approach to risk governance in the area and the narrowly-circumscribed competence under Article 152(4)(a) EC, which permits the adoption of risk regulation regimes that set minimum standards of quality and safety in relation to blood, tissue/cells and organs. Second, it has led to the development of institutional arrangements that promote a bifurcated approach to risk governance, specifically in relation to blood and tissues/cells. Although a hybrid of traditional and new governance mechanisms have been employed to address this problem of disconnection, this has nevertheless added a further layer to already complex institutional arrangements for risk governance in the area. It is suggested that a more integrated approach to EU risk governance in relation to human material is needed. Implementing such an approach would contribute to greater clarity, transparency and accountability in decision-making processes, and this could enhance public trust in what is a politically-sensitive area of governance at EU level. PMID:23326180

  18. Diesel quality trends in the EU impact the US

    SciTech Connect

    Dave, D.; Hamilton, G.

    1997-05-01

    Refiners in Europe are changing their distillate hydrotreating operations to shoot at a target that is moving much faster than in the U.S. The change in the EU is driven by a combination of legislation, encouragement through tax incentives and new market requirements. It may, therefore, be beneficial for the industry to take a proactive stance on setting the standard for environmental diesel sooner than latter. Consider cost effective options for meeting future middle distillate specifications are discussed.

  19. Studies of 27Al NMR in EuAl4

    NASA Astrophysics Data System (ADS)

    Niki, H.; Nakamura, S.; Higa, N.; Kuroshima, H.; Toji, T.; Yogi, M.; Nakamura, A.; Hedo, M.; Nakama, T.; Ōnuki, Y.; Harima, H.

    2015-03-01

    EuAl4 orders antiferromagnetically at TN ≈ 16 K with an effective magnetic moment of 8.02 μB. In the paramagnetic phase, the magnetic susceptibility of EuAl4 follows the Curie-Weiss law with a positive Curie-Weiss temperature θP = +14 K. The antiferromagnetic state is changed into the field induced ferromagnetic state at a critical field Hc of approximately 2 T. In order to microscopically investigate the magnetic and electronic properties in EuAl4, the NMR measurements of EuAl4 have been carried out at temperatures between 2 and 300 K, applying an external magnetic field of approximately 6.5 T. The 27Al NMR spectra corresponding to Al(I) and Al(II) sites are obtained. From the 27Al NMR spectra, the isotropic part Kiso and anisotropic part Kaniso of Knight shift, and nuclear quadrupole frequncy νQ are obtained. The Kiso and Kaniso shift to negative side with decreasing temperature due to the RKKY interaction. These temperature dependences follow the Curie-Weiss law with θP = +14 K, which is consistent with that of the magnetic susceptibility. From the K - χ plot, the values of the hyperfine fields Hhf_iso and Hhf_aniso are -3.231 and -0.162 kOe/μB for Al(I) site, and -1.823 and -0.264 kOe/μB for Al(II) site, respectively. The values of νQ of 27Al nucleus for Al(I) and Al(II) sites are approximately 0.865 and 0.409 MHz, respectively. The nuclear relaxation time T1 of 27Al NMR for both sites is almost constant in the paramagnetic phase, while the value of 1/T1 is abruptly decreased in the ordered ferromagnetic state.

  20. Thermoluminescence of Eu activated LiF nanophosphors

    SciTech Connect

    Kumar, Satinder; Sharma, A. K.; Lochab, S. P.; Kumar, Ravi

    2012-06-05

    Nanocrystalline lithium fluoride (LiF) phosphors prepared by the chemical co-precipitation method at 8.00 pH value have been activated with Eu (0.01, 0.03, 0.07 and 0.1%nt;) as single dopants. The formation of nanocrystalline structure has been confirmed by X-ray diffraction. Thermolumniscence (TL) properties of LiF: Eu nano-phosphors irradiated with gamma rays at different doses of 100 Gy - 10 kGy have been further studied. There is only one main glow peak at around 122 deg. C; which shifts to higher temperature with an increase in doping concentration at all studied irradiation doses. However, the glow peak shifts to lower temperature with an increase in irradiation dose from 100 Gy to 10 kGy. The LiF nano-crystallites synthesized at 8.00 pH and activated with 0.03%nt; Eu are found to have maximum TL sensitivity at studied gamma doses.

  1. Regulatory landscape for cell therapy--EU view.

    PubMed

    McBlane, James W

    2015-09-01

    This article addresses regulation of cell therapies in the European Union (EU), covering cell sourcing and applications for clinical trials and marketing authorisation applications. Regulatory oversight of cell sourcing and review of applications for clinical trials with cell therapies are handled at national level, that is, separately with each country making its own decisions. For clinical trials, this can lead to different decisions in different countries for the same trial. A regulation is soon to come into force that will address this and introduce a more efficient clinical trial application process. However, at the marketing authorisation stage, the process is pan-national: the Committee for Human Medicinal Products (CHMP) is responsible for giving the final scientific opinion on all EU marketing authorisation applications for cell therapies: favourable scientific opinions are passed to the European Commission (EC) for further consultation and, if successful, grant of a marketing authorisation valid in all 28 EU countries. In its review of applications for marketing authorisations (MAAs) for cell therapies, the CHMP is obliged to consult the Committee for Advanced Therapies (CAT), who conduct detailed scientific assessments of these applications, with assessment by staff from national regulatory authorities and specialist advisors to the regulators. PMID:25997566

  2. Thermal and optical properties of Tb(III), Eu(III) and Tb(III)/Eu(III) co-complexed silicone fluorinated acrylate copolymer

    NASA Astrophysics Data System (ADS)

    Zhai, Yinfeng; Xie, Hongde; Cai, Haijun; Cai, Peiqing; Seo, Hyo Jin

    2015-07-01

    Tb(III), Eu(III) and Tb(III)/Eu(III) activated silicone fluorinated acrylate (SFA) have been successfully synthesized using the method of semi-continuous emulsion polymerization. The copolymers are characterized by flourier transform infrared (FT-IR), thermal gravity analysis (TGA), photoluminescence excitation (PLE) and emission (PL) spectroscopy. The copolymer containing Tb(III) and Eu(III) ions display green and red luminescent colors under UV light excitation, respectively. The TGA curves show the thermal decomposition temperatures of the copolymers are up to about 300 °C. The PL spectra show a strong green emission at 546 nm (5D4 → 7F5) of Tb(III) complexed copolymers, and show a prominent red emission at 615 nm (5D0 → 7F2) of Eu(III) complexed copolymers. Different concentrations of Eu(III) and Tb(III) ions are introduced into the copolymer and the energy transfer from Tb(III) to Eu(III) ions in the copolymer was found. Thus, based on the results it can be suggested that SFA:Eu(III), SFA:Tb(III) and SFA:Tb(III)/Eu(III) can be used potentially as luminescent materials.

  3. Concentration effect of H/OH and Eu{sup 3+} species on activating photoluminescence from ZnO:Eu{sup 3+} thin films

    SciTech Connect

    Akazawa, Housei; Shinojima, Hiroyuki

    2013-10-21

    We identified the conditions necessary for photoluminescence from Eu{sup 3+} ions doped in ZnO thin films to occur via indirect excitation of ZnO host crystal with a 325-nm laser light. The ZnO:Eu films were sputter-deposited on Si(100) substrates at room temperature with H{sub 2}O vapor flowing as the oxygen source gas. A very narrow emission peak at 612 nm, assigned to {sup 5}D{sub 0}−{sup 7}F{sub 2} transition of Eu{sup 3+} ions, appeared after annealing at 200–300 °C in a vacuum or at 500 °C in an O{sub 2} ambient. At temperatures higher than these, the 612-nm emission peak attenuated and emission spectra exhibited weaker double peaks at 612 and 620 nm. This observation suggested that most Eu{sup 3+} ions withdrew from the most emission-active sites, and occupied two distinct chemical sites. With further increasing temperature, the double peaks merged to become broader, indicating that Eu{sup 3+} ions occupied sites more randomly. Emission intensity was the highest at an Eu content of 0.9 at. % and concentration quenching was observed as Eu content was increased. Substitution of Zn{sup 2+} cation sites with Eu{sup 3+} ions was confirmed from the primary X-ray diffraction peaks of ZnO(002); the ZnO lattice expanded as larger numbers of Eu{sup 3+} ions were incorporated. After the films were post-annealed at high temperatures, the diffraction angles approached those of undoped ZnO crystals, which reflected shifting Eu{sup 3+} ions into grain boundaries. The photoabsorption of OH species within a wavelength range of 2700–3000 nm and the Eu{sup 3+} emission intensity revealed correlated behavior. These results confirmed that the presence of OH and/or H species in the film is necessary for emissions from Eu{sup 3+} ions to appear. When OH and/or H species were diminished after high-temperature annealing, Eu{sup 3+} ions existing at substitutional sites became unstable and their emissions were consequently deactivated. The origin of emission-active Eu{sup 3

  4. Regulatory aspects of nanotechnology in the agri/feed/food sector in EU and non-EU countries.

    PubMed

    Amenta, Valeria; Aschberger, Karin; Arena, Maria; Bouwmeester, Hans; Botelho Moniz, Filipa; Brandhoff, Puck; Gottardo, Stefania; Marvin, Hans J P; Mech, Agnieszka; Quiros Pesudo, Laia; Rauscher, Hubert; Schoonjans, Reinhilde; Vettori, Maria Vittoria; Weigel, Stefan; Peters, Ruud J

    2015-10-01

    Nanotechnology has the potential to innovate the agricultural, feed and food sectors (hereinafter referred to as agri/feed/food). Applications that are marketed already include nano-encapsulated agrochemicals or nutrients, antimicrobial nanoparticles and active and intelligent food packaging. Many nano-enabled products are currently under research and development, and may enter the market in the near future. As for any other regulated product, applicants applying for market approval have to demonstrate the safe use of such new products without posing undue safety risks to the consumer and the environment. Several countries all over the world have been active in examining the appropriateness of their regulatory frameworks for dealing with nanotechnologies. As a consequence of this, different approaches have been taken in regulating nano-based products in agri/feed/food. The EU, along with Switzerland, were identified to be the only world region where nano-specific provisions have been incorporated in existing legislation, while in other regions nanomaterials are regulated more implicitly by mainly building on guidance for industry. This paper presents an overview and discusses the state of the art of different regulatory measures for nanomaterials in agri/feed/food, including legislation and guidance for safety assessment in EU and non-EU countries. PMID:26169479

  5. Hydrothermal Synthesis and Luminescence Properties of Eu²⁺- and Eu³⁺-Doped SrAIF₅ Nanorods.

    PubMed

    Zhang, Wei; Hua, Ruinian; Zhao, Jun; Tang, Dongxin; Zhao, Xin; Na, Liyan; Zhang, Jinsu; Chen, Baojiu

    2016-01-01

    Eu²⁺- and Eu³⁺-doped SrAIF₅ nanorods were synthesized via a hydrothermal process. The crystal structure and morphology of the final products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The prepared nanorods' diameters range from 40 to 50 nm, and lengths range from 400 nm to 2 µm along with the doped concentration of rare earth. The f-f transitions of Eu²⁺ can be observed in the SrAlF₅:Eu²⁺ nanorods at room temperature, and the photo-luminescent (PL) properties of SrAlF₅:Eu³⁺ nanorods are also described. PMID:27398485

  6. Luminescence and second harmonic generation in Eu 3+ /Eu 2+ embedded B 2 O 3 : LiNbO 3 non-linear glass-ceramics

    NASA Astrophysics Data System (ADS)

    Yadav, T. K.; Singh, A. K.; Kumar, K.; Yadav, R. A.

    2011-09-01

    Multifunctional europium doped Li 2O-Nb 2O 3-B 2O 2 glass has been prepared by melt-quench method. Through subsequent heat treatments glass has then been transformed into glass ceramics containing ferroelectric LiNbO 3 phase. The glass ceramics have shown enhanced Eu 3+ emission compared to parent glass when excited by 266 nm radiation. The emission measurements of glass ceramics have also shown the presence of Eu 2+ state along with Eu 3+ and Eu 2+ state was found to increase when glass was heated in inert atmosphere. Lifetime of the 5D 0 level of the Eu 3+ has been measured and a significant increase is found in case of glass ceramic prepared around glass transition temperature. Glass ceramics have also shown good second harmonic generation (SHG) with pulsed 1064 nm laser excitation.

  7. Cyan-emitting LiBaBO3:Eu2+ phosphor: Crystal structure and luminescence property comparison with LiSrBO3:Eu2+

    NASA Astrophysics Data System (ADS)

    Huang, Zhaohui; Ji, Haipeng; Fang, Minghao; Molokeev, Maxim S.; Liu, Shuyue; Liu, Yan'gai; Wu, Xiaowen

    2015-05-01

    Cyan-emitting LiBaBO3:Eu2+ phosphor was synthesized by solid-state reaction at 800 °C. Structure refinement by Rietveld method reveals that LiBaBO3 crystallizes in a monoclinic cell, space groups P21/c or P21/n. Upon 365 nm excitation, LiBaBO3:Eu2+ shows a symmetric emission band peaking at 496 nm with full-width at half-maximum of 80 nm; when monitoring at 496 nm, a broad excitation band in the UV region (250-420 nm) is observed. The luminescence property of LiBaBO3:Eu2+ is considerably different from LiSrBO3:Eu2+ which holds the same space group. The local structures of the two hosts are compared to explain the different behaviors of Eu2+.

  8. Progress in the use of Quantum Dye Eu(III)-macrocycles

    NASA Astrophysics Data System (ADS)

    Leif, Robert C.; Becker, Margie C.; Vallarino, Lidia M.; Williams, John W.; Yang, Sean

    2003-06-01

    A Eu(III)-macrocycle-mono-isothiocyanate, Quantum Dye, has been synthesized that has minimal contamination with the Eu(III)-macrocycle-di-isothiocyanate, which cross-links proteins. The mono-isothiocyanate has been conjugated to streptavidin (EuMac-Strept). An indirect assay with EuMac-Strept and biotinylated anti5BrdU has been used to observe apoptotic cells. This system and cells directly labeled with the Eu(III)-macrocycle-di-isothiocyanate have been employed in fading studies and reagent stability tests. The fading of cells mounted in a plastic medium was much slower than that observed when the cells were in the aqueous, micellar Lanthanide Enhanced Luminescence (LEL) solution. The fading was not the result of the photo-destruction of the Eu(III)-macrocycle, since the luminescence returned after a second addition of the LEL solution. A time-gated, peltier cooled, monochrome CCD camera has been combined with a flashlamp to eliminate imaging of the emission of fluorescein while maintaining the images of EuMAc staining. This was demonstrated with both separate preparations of fluorescein and EuMac stained cells and mixtures thereof. Time-gating was employed to produce an EuMac image of cells that were stained with both the EuMac and DAPI.

  9. Photoluminescence and doping mechanism of theranostic Eu3+/Fe3+ dual-doped hydroxyapatite nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Min-Hua; Yoshioka, Tomohiko; Ikoma, Toshiyuki; Hanagata, Nobutaka; Lin, Feng-Huei; Tanaka, Junzo

    2014-10-01

    Theranostic nanoparticles currently have been regarded as an emerging concept of ‘personalized medicine’ with diagnostic and therapeutic dual-functions. Eu3+ doped hydroxyapatite (HAp) has been regarded as a promising fluorescent probe for in vivo imaging applications. Additionally, substitution of Ca2+ with Fe3+ in HAp crystal may endow the capability of producing heat upon exposure to a magnetic field. Here we report a preliminary study of doping mechanism and photoluminescence of Eu3+ and Fe3+ doped HAp nanoparticles (Eu/Fe:HAp). HAp with varied concentration of Eu3+ and Fe3+ doping are presented as Eu(10 mol%):HAp, Eu(7 mol%)-Fe(3 mol%):HAp, Eu(5 mol%)-Fe(5 mol%):HAp, Eu(3 mol%)-Fe(7 mol%):HAp, and Fe(10 mol%):HAp in the study. The results showed that the HAp particles, in nano-size with rod-like morphology, were successfully doped with Eu3+ and Fe3+, and the particles can be well suspended in cell culture medium. Photoluminescence analysis revealed that particles have prominent emissions at 536 nm, 590 nm, 615 nm, 650 nm and 695 nm upon excitation at a wavelength of 397 nm. Moreover, these Eu/Fe:HAp nanoparticles belonged to B-type carbonated HAp, which has been considered an effective biodegradable and biocompatible drug/gene carrier in biological applications.

  10. Structure and multiferroic properties of Eu-substituted BiFeO3 ceramics

    NASA Astrophysics Data System (ADS)

    Dai, Haiyang; Chen, Zhenping; Xue, Renzhong; Li, Tao; Liu, Haizeng; Wang, Yongqiang

    2013-06-01

    Polycrystalline Bi1- x Eu x FeO3 ( x=0.00-0.25) ceramics were synthesized by the solid state reaction method with the rapid liquid phase sintering process. The effects of Eu substitution on the structure, and ferroelectric and magnetic properties of BiFeO3 ceramics were investigated. X-ray diffraction measurements reveal that the structure of BiFeO3 was changed from rhombohedral to orthorhombic and the impurity phases were decreased both due to Eu substitution. Raman spectra results also confirm that a structure transition occurs in the Eu concentration range of 0.15-0.20. The SEM investigation has suggested that the Eu substitution hinders the grain growth. Vibrating sample magnetometer measurements indicate ferromagnetism in Eu-substituted BiFeO3 ceramics. It is found that the room temperature magnetic moment increases with increasing Eu concentration due to the suppressed or broken cycloid spin structure. Ferroelectric measurements show that Eu substitution enhances the polarization due to the significant decrease of the electric leakage of the samples. Therefore, the Eu-substituted BiFeO3, or more complicated substituted BiFeO3 based on Eu substitution, will have great potential for many practical applications.

  11. Luminescence and Site Occupancy of Eu2+ in Ba2 Ca(BO3)2

    NASA Astrophysics Data System (ADS)

    Li, Pan-Lai; Wang, Zhi-Jun; Yang, Zhi-Ping; Guo, Qing-Lin

    2011-01-01

    A green phosphor Ba2Ca(BO3)2:Eu2+ was synthesized by a high temperature solid-state reaction method under a reductive atmosphere. The luminescence and site occupancy of Eu2+ in Ba2Ca(BO3)2 are investigated. Ba2Ca(BO3)2:Eu2+ shows one green band (537 nm) under 400 nm near ultraviolet excitation which is suitable for UV LED. Ca2+ and Ba2+ ions in Ba2Ca(BO3)2 are replaced by Eu2+ ions, the Ba2Ca(BO3)2:Eu2+ shows a dissymmetrical emission band. The influence of Eu2+ doping concentrations on the emission intensity of Ba2Ca(BO3)2:Eu2+ is studied. It is found that the emission intensity is influenced by the Eu2+ concentration and reaches the maximum value at 2% Eu2+. According to the Dexter theory, the concentration quenching mechanisms of Eu2+ in Ba2Ca(BO3)2 are the d-dinteraction.

  12. Structure and photoluminescence of Mg-Al-Eu ternary hydrotalcite-like layered double hydroxides

    SciTech Connect

    Chen Yufeng; Li Fei; Zhou Songhua; Wei Junchao; Dai Yanfeng; Chen Yiwang

    2010-09-15

    A series of Mg-Al-Eu ternary hydrotalcite-like layered double hydroxides (LDHs), with Eu/Al atomic ratios of {approx}0.06 and Mg/(Al+Eu) atomic ratios ranging from 1.3 to 4.0, were synthesized by a coprecipitation method. The Mg-Al-Eu ternary LDHs were investigated by various techniques. X-ray diffraction (XRD) results indicated that the crystallinity of the ternary LDHs was gradually improved with the increase of Mg{sup 2+}/(Al{sup 3+}+Eu{sup 3+}) molar ratio from 1.3/1 to 4/1, and all the samples were a single phase corresponding to LDH. The photoluminescent (PL) spectra of the ternary Mg-Al-Eu LDHs were described by the well-known {sup 5}D{sub 0}-{sup 7}F{sub J} transition (J=1, 2, 3, 4) of Eu{sup 3+} ions with the strongest emission for J=2, suggesting that the host LDH was favorable to the emissions of Eu{sup 3+} ions. The asymmetry parameter (R) relevant to {sup 5}D{sub 0}-{sup 7}F{sub J} transition (J=1, 2) dependant of the atomic ratios of Mg{sup 2+}/(Al{sup 3+}+Eu{sup 3+}) was discussed, and was consistent with the result of XRD. - Graphical abstract: A series of Mg-Al-Eu ternary hydrotalcite-like layered double hydroxides (LDHs), with Mg/(Al+Eu) atomic ratios ranging from 1.3/1, 2/1 3/1 to 4/1, were synthesized by a coprecipitation method. The photoluminescent spectra of the Mg-Al-Eu ternary LDHs are described by the well-known {sup 5}D{sub 0}-{sup 7}F{sub J} transition (J=1, 2, 3, 4) of Eu{sup 3+} ions with the strongest emission for J=2.

  13. Interactions between Eu{sup 3+} ions in inorganic-organic hybrid materials

    SciTech Connect

    Pelle, Fabienne; Aschehoug, Patrick; Surble, Suzy; Millange, Franck; Serre, Christian; Ferey, Gerard

    2010-04-15

    The optical properties of two-dimensional lanthanide dicarboxylates EuBDC or Eu{sub 2}(H{sub 2}O){sub 2}(O{sub 2}C-C{sub 6}H{sub 4}-CO{sub 2}){sub 3} and EuCDC (denoted also MIL94) or Eu{sub 2}(H{sub 2}O){sub 4}(O{sub 2}C-C{sub 6}H{sub 10}-CO{sub 2}){sub 3}.2H{sub 2}O are reported. The structures are built up from dimers of corner-sharing polyhedra and 1,3-benzenedicarboxylate (BDC) for EuBDC and from dimers of edge-sharing polyhedra and 1,3-benzenedicarboxylate (CDC) for EuCDC. The high Eu{sup 3+} concentration and the weak luminescence quenching allow the study of Eu{sup 3+} interactions. Anti-Stokes spectra from {sup 5}D{sub 1} are observed with excitation in {sup 5}D{sub 0}. These results are very unusual for Eu{sup 3+} ions and reflect strong interactions between ions within a dimer. Excitation spectrum of the Eu{sup 3+} luminescence strongly differs in both compounds in the UV range. In case of EuBDC, an efficient sensitization of the luminescence due to the ligand is observed between 250 and 350 nm while only 4f-4f transitions are recorded on the Eu{sup 3+} excitation spectrum in EuCDC. The efficiency of the sensitization of the rare earth by the host is discussed by taking into account the geometrical arrangement and the electronic delocalization of the ligands. - Graphical abstract: Excitation spectra monitoring the {sup 5}D{sub 0}->{sup 7}F{sub 2} transition with a dimer structure.

  14. Comparative adsorption of Eu(III) and Am(III) on TPD.

    PubMed

    Fan, Q H; Zhao, X L; Ma, X X; Yang, Y B; Wu, W S; Zheng, G D; Wang, D L

    2015-09-01

    Comparative adsorption behaviors of Eu(III) and Am(III) on thorium phosphate diphosphate (TPD), i.e., Th4(PO4)4P2O7, have been studied using a batch approach and surface complexation model (SCM) in this study. The results showed that Eu(III) and Am(III) adsorption increased to a large extent with the increase in TPD dose. Strong pH-dependence was observed in both Eu(III) and Am(III) adsorption processes, suggesting that inner-sphere complexes (ISCs) were possibly responsible for the adsorption of Eu(III) and Am(III). Meanwhile, the adsorption of Eu(III) and Am(III) decreased to a different extent with the increase in ion strength, which was possibly related to outer-sphere complexes and/or ion exchange. In the presence of fulvic acid (FA), the adsorption of Eu(III) and Am(III) showed high enhancement mainly due to the ternary surface complexes of TPD-FA-Eu(3+) and TPD-FA-Am(3+). The SCM showed that one ion exchange (≡S3Am/Eu) and two ISCs (≡(XO)2Am/EuNO3 and ≡(YO)2Am/EuNO3) seemed more reasonable to quantitatively describe the adsorption edges of both Eu(III) and Am(III). Our findings obviously showed that Eu(III) could be a good analogue to study actinide behaviors in practical terms. However, it should be kept in mind that there are still obvious differences between the characteristics of Eu(III) and Am(III) in some special cases, for instance, the complex ability with organic matter and adsorption affinity to a solid surface. PMID:26198355

  15. Preferential Eu Site Occupation and Its Consequences in the Ternary Luminescent HalidesAB2I5:Eu2+(A=Li–Cs;B=Sr, Ba)

    DOE PAGESBeta

    Fang, C.  M.; Biswas, Koushik

    2015-07-22

    Several rare-earth-doped, heavy-metal halides have recently been identified as potential next-generation luminescent materials with high efficiency at low cost. AB2I5:Eu2+ (A=Li–Cs; B=Sr, Ba) is one such family of halides. Its members, such as CsBa2I5:Eu2+ and KSr2I5:Eu2+, are currently being investigated as high-performance scintillators with improved sensitivity, light yield, and energy resolution less than 3% at 662 keV. Within the AB2I5 family, our first-principles-based calculations reveal two remarkably different trends in Eu site occupation. The substitutional Eu ions occupy both eightfold-coordinated B1(VIII) and the sevenfold-coordinated B2(VII) sites in the Sr-containing compounds. However, in the Ba-containing crystals, Eu ions strongly prefer themore » B2(VII)sites. This random versus preferential distribution of Eu affects their electronic properties. The calculations also suggest that in the Ba-containing compounds one can expect the formation of Eu-rich domains. These results provide atomistic insight into recent experimental observations about the concentration and temperature effects in Eu-doped CsBa2I5. We discuss the implications of our results with respect to luminescent properties and applications. We also hypothesize Sr, Ba-mixed quaternary iodides ABaVIIISrVIII5:Eu as scintillators having enhanced homogeneity and electronic properties.« less

  16. Eu{sub 3}F{sub 4}S{sub 2}: Synthesis, crystal structure, and magnetic properties of the mixed-valent europium(II,III) fluoride sulfide EuF{sub 2}.(EuFS){sub 2}

    SciTech Connect

    Grossholz, Hagen; Hartenbach, Ingo; Kotzyba, Gunter; Poettgen, Rainer; Trill, Henning; Mosel, Bernd D.; Schleid, Thomas

    2009-11-15

    Using the method to synthesize rare-earth metal(III) fluoride sulfides MFS (M=Y, La, Ce-Lu), in some cases we were able to obtain mixed-valent compounds such as Yb{sub 3}F{sub 4}S{sub 2} instead. With Eu{sub 3}F{sub 4}S{sub 2} another isotypic representative has now been synthesized. Eu{sub 3}F{sub 4}S{sub 2} (tetragonal, I4/mmm, a=400.34(2), c=1928.17(9) pm, Z=2) is obtained from the reaction of metallic europium, elemental sulfur, and europium trifluoride in a molar ratio of 5:6:4 within seven days at 850 deg. C in silica-jacketed gas-tightly sealed platinum ampoules. The single-phase product consists of black plate-shaped single crystals with a square cross section, which can be obtained from a flux using equimolar amounts of NaCl as fluxing agent. The crystal structure is best described as an intergrowth structure, in which one layer of CaF{sub 2}-type EuF{sub 2} is followed by two layers of PbFCl-type EuFS when sheeted parallel to the (001) plane. Accordingly there are two chemically and crystallographically different europium cations present. One of them (Eu{sup 2+}) is coordinated by eight fluoride anions in a cubic fashion, the other one (Eu{sup 3+}) exhibits a monocapped square antiprismatic coordination sphere with four F{sup -} and five S{sup 2-} anions. Although the structural ordering of the different charged europium cations is plausible, a certain amount of charge delocalization with some polaron activity has to take place, which is suggested by the black color of the title compound. Temperature dependent magnetic susceptibility measurements of Eu{sub 3}F{sub 4}S{sub 2} show Curie-Weiss behavior with an experimental magnetic moment of 8.19(5) mu{sub B} per formula unit and a paramagnetic Curie temperature of 0.3(2) K. No magnetic ordering is observed down to 4.2 K. In accordance with an ionic formula splitting like (Eu{sup II})(Eu{sup III}){sub 2}F{sub 4}S{sub 2} only one third of the europium centers in Eu{sub 3}F{sub 4}S{sub 2} carry permanent

  17. Superconductivity and ferromagnetism in hole-doped RbEuFe4As4

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Liu, Ya-Bin; Tang, Zhang-Tu; Jiang, Hao; Wang, Zhi-Cheng; Ablimit, Abduweli; Jiao, Wen-He; Tao, Qian; Feng, Chun-Mu; Xu, Zhu-An; Cao, Guang-Han

    2016-06-01

    We discover a robust coexistence of superconductivity and ferromagnetism in an iron arsenide RbEuFe4As4 . The new material crystallizes in an intergrowth structure of RbFe2As2 and EuFe2As2 , such that the Eu sublattice turns out to be primitive instead of being body-centered in EuFe2As2 . The FeAs layers, featured by asymmetric As coordinations, are hole doped due to charge homogenization. Our combined measurements of electrical transport, magnetization, and heat capacity unambiguously and consistently indicate bulk superconductivity at 36.5 K in the FeAs layers and ferromagnetism at 15 K in the Eu sublattice. Interestingly, the Eu-spin ferromagnetic ordering belongs to a rare third-order transition, according to the Ehrenfest classification of phase transitions. We also identify an additional anomaly at ˜5 K, which is possibly associated with the interplay between superconductivity and ferromagnetism.

  18. Fabrication of luminescent Eu{sub 2}O{sub 3} superstructures.

    SciTech Connect

    Pol, V. G.; Calderon-Moreno, J. M.; Chemical Sciences and Engineering Division; Inst. of Physical Chemistry

    2010-01-01

    This Letter demonstrates a solvent-free efficient synthesis process to prepare self-assembled two-dimensional Eu{sub 2}O{sub 3} luminescent nanoplates to yield a superstructure. In the first step, Eu{sub 2}O{sub 3}CO{sub 3} superstructures are fabricated by the thermolysis [700C] of a single precursor, europium acetate, in a closed reactor under autogenic pressure. The as-prepared Eu{sub 2}O{sub 3}CO{sub 3} superstructures are further heated in air to 750C to facilitate the fabrication of Eu{sub 2}O{sub 3} superstructures. A systematic morphological, structural, and compositional characterization of Eu{sub 2}O{sub 3} superstructures is carried out. The photoluminescent properties and mechanism for the strong red emission of the photoexcited Eu{sub 2}O{sub 3} superstructures is proposed.

  19. Enhanced luminescence in Eu-doped ZnO nanocrystalline films

    SciTech Connect

    Suzuki, Keigo Murayama, Koji; Tanaka, Nobuhiko

    2015-07-20

    We found an enhancement of Eu{sup 3+} emissions in Eu-doped ZnO nanocrystalline films fabricated by microemulsion method. The Eu{sup 3+} emission intensities were increased by reducing annealing temperatures from 633 K to 533 K. One possible explanation for this phenomenon is that the size reduction enhances the energy transfer from ZnO nanoparticles to Eu{sup 3+} ions. Also, the shift of the charge-transfer band into the low-energy side of the absorption edge is found to be crucial, which seems to expedite the energy transfer from O atoms to Eu{sup 3+} ions. These findings will be useful for the material design of Eu-doped ZnO phosphors.

  20. Temperature-dependent luminescent properties of Eu-Tb complexes synthesized in situ in gel glass

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Qian, Guodong; Wang, Zhiyu; Wang, Minquan

    2005-02-01

    The chelates of europium and terbium with hexafluoroacetylacetone (HFA) and triphenylphoshine oxide (TPPO), Eu /Tb(HFA)3(TPPO)2, have been synthesized in situ in gel glasses with various concentrations of Eu3+ and Tb3+ ions. The photoluminescence spectra have been measured and the characteristic transitions of Tb3+ and Eu3+ have been observed. Due to the variance of energy transfer efficiencies from Tb3+ to Eu3+, the intensity ratios of europium luminescent band to terbium band vary remarkably with measurement temperatures. In addition, the Förster mechanism has been proved to be responsible for the energy transfer between Eu3+ and Tb3+. The materials doped with Eu /Tb(HFA)3(TPPO)2 are promising for being used as a temperature detector and thermal-sensitive probe of optical fiber sensor.

  1. Enhanced luminescence in Eu-doped ZnO nanocrystalline films

    NASA Astrophysics Data System (ADS)

    Suzuki, Keigo; Murayama, Koji; Tanaka, Nobuhiko

    2015-07-01

    We found an enhancement of Eu3+ emissions in Eu-doped ZnO nanocrystalline films fabricated by microemulsion method. The Eu3+ emission intensities were increased by reducing annealing temperatures from 633 K to 533 K. One possible explanation for this phenomenon is that the size reduction enhances the energy transfer from ZnO nanoparticles to Eu3+ ions. Also, the shift of the charge-transfer band into the low-energy side of the absorption edge is found to be crucial, which seems to expedite the energy transfer from O atoms to Eu3+ ions. These findings will be useful for the material design of Eu-doped ZnO phosphors.

  2. Luminescent Characteristics of LiSrBO3:Eu3+ Phosphor for White Light Emitting Diode

    NASA Astrophysics Data System (ADS)

    Li, Pan-Lai; Wang, Zhi-Jun; Yang, Zhi-Ping; Guo, Qing-Lin

    2009-04-01

    LiSrBO3:Eu3+ phosphor is synthesized by a high solid-state reaction method, and its luminescent characteristics are investigated. The emission and excitation spectra of LiSrBO3:Eu3+ phosphors exhibit that the phosphors can be effectively excited by near ultraviolet (401 nm) and blue (471 nm) light, and emit 615 nm red light. The effect of Eu3+ concentration on the emission spectrum of LiSrBO3:Eu3+ phosphor is studied; the results show that the emission intensity increases with increasing Eu3+ concentration, and then decreases because of concentration quenching. It reaches the maximum at 3 mol%, and the concentration self-quenching mechanism is the dipoledipole interaction according to the Dexter theory. Under the conditions of charge compensation Li+, Na+ or K+ incorporated in LiSrBO3, the luminescent intensities of LiSrBO3:Eu3+ phosphor are enhanced.

  3. Growth and characterization of Sc-doped EuO thin films

    SciTech Connect

    Altendorf, S. G.; Reisner, A.; Chang, C. F.; Hollmann, N.; Rata, A. D.; Tjeng, L. H.

    2014-02-03

    The preparation of 3d-transition metal-doped EuO thin films by molecular beam epitaxy is investigated using the example of Sc doping. The Sc-doped EuO samples display a good crystalline structure, despite the relatively small ionic radius of the dopant. The Sc doping leads to an enhancement of the Curie temperature to up to 125 K, remarkably similar to previous observations on lanthanide-doped EuO.

  4. Low temperature synthesis of nanocrystalline YVO 4:Eu via polyacrylamide gel method

    NASA Astrophysics Data System (ADS)

    Zhang, Hongwu; Fu, Xiaoyan; Niu, Shuyun; Sun, Gongquan; Xin, Qin

    2004-08-01

    Nanocrystalline europium doped yttrium orthovanadate (YVO 4:Eu) were synthesized by the polyacrylamide gel method. For a comparative evaluation, bulk YVO 4:Eu was prepared by solid-state reaction. On the basis of X-ray powder diffraction, scanning and transmission electron microscopy and luminescence measurements, the polyacrylamide gel method appears to be a more efficient method to prepare the luminescence materials YVO 4:Eu with high homogeneity, purity and luminescence intensity.

  5. Magnetic properties of EuLn{sub 2}O{sub 4} (Ln=rare earths)

    SciTech Connect

    Hirose, Keiichi; Doi, Yoshihiro; Hinatsu, Yukio

    2009-07-15

    Ternary rare earth oxides EuLn{sub 2}O{sub 4} (Ln=Gd, Dy-Lu) were prepared. They crystallized in an orthorhombic CaFe{sub 2}O{sub 4}-type structure with space group Pnma. {sup 151}Eu Moessbauer spectroscopic measurements show that the Eu ions are in the divalent state. All these compounds show an antiferromagnetic transition at 4.2-6.3 K. From the positive Weiss constant and the saturation of magnetization for EuLu{sub 2}O{sub 4}, it is considered that ferromagnetic chains of Eu{sup 2+} are aligned along the b-axis of the orthorhombic unit cell, with neighboring Eu{sup 2+} chains antiparallel. When Ln=Gd-Tm, ferromagnetically aligned Eu{sup 2+} ions interact with the Ln{sup 3+} ions, which would overcome the magnetic frustration of triangularly aligned Ln{sup 3+} ions and the EuLn{sub 2}O{sub 4} compounds show a simple antiferromagnetic behavior. - Graphical abstract: Ternary rare earth oxides EuLn{sub 2}O{sub 4} (Ln=Gd, Dy-Lu) crystallized in an orthorhombic CaFe{sub 2}O{sub 4}-type structure with space group Pnma. Moessbauer spectroscopic measurements show that the Eu ions are in the divalent state. All these compounds show an antiferromagnetic transition at 4.2-6.3 K. It is considered that ferromagnetic chains of Eu{sup 2+} are aligned along the b-axis of the orthorhombic unit cell, with neighboring Eu{sup 2+} chains antiparallel.

  6. Differential scanning calorimetry investigations on Eu-doped fluorozirconate-based glass ceramics

    PubMed Central

    Paßlick, C.; Ahrens, B.; Henke, B.; Johnson, J. A.; Schweizer, S.

    2010-01-01

    The properties of Eu-doped fluorochlorozirconate (FCZ) glass ceramics upon thermal processing and the influence of Eu-doping on the formation of BaCl2 nanocrystals therein have been investigated. Differential scanning calorimetry indicates that higher Eu-doping shifts the crystallization peak of the nanocrystals in the glass to lower temperatures, while the glass transition temperature remains constant. The activation energy and the thermal stability parameters for the BaCl2 crystallization are determined. PMID:21286235

  7. [Eu ⊂ bpy·bpy·bpy] + cryptate: Luminescence and conformation

    NASA Astrophysics Data System (ADS)

    Blasse, G.; Dirksen, G. J.; van der Voort, D.; Sabbatini, N.; Perathoner, S.; Lehn, J.-M.; Alpha, B.

    1988-05-01

    The luminescence of [Eu ⊂ bpy·bpy·bpy] 3+ cryptate is reported for the solid (down to 4.2 K) and for molecules in porous glass. Energy transfer from the cryptand to Eu 3+ occurs with high efficiency. The emission spectra are used to evaluate the molecular conformation of the cryptate. The Eu 3+ ion appears to be off-centre.

  8. Polyethylene recycling: Waste policy scenario analysis for the EU-27.

    PubMed

    Andreoni, Valeria; Saveyn, Hans G M; Eder, Peter

    2015-08-01

    This paper quantifies the main impacts that the adoption of the best recycling practices together with a reduction in the consumption of single-use plastic bags and the adoption of a kerbside collection system could have on the 27 Member States of the EU. The main consequences in terms of employment, waste management costs, emissions and energy use have been quantified for two scenarios of polyethylene (PE) waste production and recycling. That is to say, a "business as usual scenario", where the 2012 performances of PE waste production and recycling are extrapolated to 2020, is compared to a "best practice scenario", where the best available recycling practices are modelled together with the possible adoption of the amended Packaging and Packaging Waste Directive related to the consumption of single-use plastic bags and the implementation of a kerbside collection system. The main results show that socio-economic and environmental benefits can be generated across the EU by the implementation of the best practice scenario. In particular, estimations show a possible reduction of 4.4 million tonnes of non-recycled PE waste, together with a reduction of around €90 million in waste management costs in 2020 for the best practice scenario versus the business as usual scenario. An additional 35,622 jobs are also expected to be created. In environmental terms, the quantity of CO2 equivalent emissions could be reduced by around 1.46 million tonnes and the net energy requirements are expected to increase by 16.5 million GJ as a consequence of the reduction in the energy produced from waste. The main analysis provided in this paper, together with the data and the model presented, can be useful to identify the possible costs and benefits that the implementation of PE waste policies and Directives could generate for the EU. PMID:25976302

  9. Geographic Data as Personal Data in Four EU Member States

    NASA Astrophysics Data System (ADS)

    de Jong, A. J.; van Loenen, B.; Zevenbergen, J. A.

    2016-06-01

    The EU Directive 95/46/EC on the protection of individuals with regard to the processing of personal data and on the free movement of such data aims at harmonising data protection legislation in the European Union. This should promote the free flow of products and services within the EU. This research found a wide variety of interpretations of the application of data protection legislation to geographic data. The variety was found among the different EU Member States, the different stakeholders and the different types of geographic data. In the Netherlands, the Data Protection Authority (DPA) states that panoramic images of streets are considered personal data. While Dutch case law judges that the data protection legislation does not apply if certain features are blurred and no link to an address is provided. The topographic datasets studied in the case studies do not contain personal data, according to the Dutch DPA, while the German DPA and the Belgian DPA judge that topographic maps of a large scale can contain personal data, and impose conditions on the processing of topographic maps. The UK DPA does consider this data outside of the scope of legal definition of personal data. The patchwork of differences in data protection legislation can be harmonised by using a traffic light model. This model focuses on the context in which the processing of the data takes place and has four categories of data: (1) sensitive personal data, (2) personal data, (3), data that can possibly lead to identification, and (4) non-personal data. For some geographic data, for example factual data that does not reveal sensitive information about a person, can be categorised in the third category giving room to opening up data under the INSPIRE Directive.

  10. The agricultural water footprint of EU river basins

    NASA Astrophysics Data System (ADS)

    Vanham, Davy

    2014-05-01

    This work analyses the agricultural water footprint (WF) of production (WFprod,agr) and consumption (WFcons,agr) as well as the resulting net virtual water import (netVWi,agr) for 365 EU river basins with an area larger than 1000 km2. Apart from total amounts, also a differentiation between the green, blue and grey components is made. River basins where the WFcons,agr,tot exceeds WFprod,agr,tot values substantially (resulting in positive netVWi,agr,tot values), are found along the London-Milan axis. River basins where the WFprod,agr,totexceeds WFcons,agr,totare found in Western France, the Iberian Peninsula and the Baltic region. The effect of a healthy (HEALTHY) and vegetarian (VEG) diet on the WFcons,agr is assessed, as well as resulting changes in netVWi,agr. For HEALTHY, the WFcons,agr,tot of most river basins decreases (max 32%), although in the east some basins show an increase. For VEG, in all but one river basins a reduction (max 46%) in WFcons,agr,tot is observed. The effect of diets on the WFcons,agrof a river basin has not been carried out so far. River basins and not administrative borders are the key geographical entity for water management. Such a comprehensive analysis on the river basin scale is the first in its kind. Reduced river basin WFcons,agrcan contribute to sustainable water management both within the EU and outside its borders. They could help to reduce the dependency of EU consumption on domestic and foreign water resources.

  11. Characterisation of frequency doubling in Eu(2+) doped aluminosilicate fibres

    NASA Technical Reports Server (NTRS)

    Driscoll, T. J.; Lawandy, N. M.; Killian, A.; Rienhart, L.; Morse, T. F.

    1991-01-01

    The results of a series of experiments on efficient second-harmonic generation in a fiber with a Eu(2+)-doped aluminosilicate core are reported. The fiber was prepared by the seeding method with CW mode-locked radiation at 1.06 micron and produced ultrastable peak conversion efficiencies of 0.001 during mode-locked readout. Experiments were performed to determine the IR preparation intensity dependence, the stability of the output, and the type of erasure mechanisms which occur. The results are compared with those of germanosilicate fibers and some similarities and differences are discussed.

  12. Magnetic properties of Eu doped BiGdO3

    NASA Astrophysics Data System (ADS)

    Nithya, R.; Yadagiri, K.; Shukla, Neeraj

    2016-05-01

    Bulk Bismuth Gadolinium Oxide, BiGdO3 and Eu doped BiGdO3 compounds were synthesized by the conventional solid state reaction in air. Phase formation of these compounds was tracked using powder X-ray characterization technique since single phase formation was found to be sensitive to thermal treatment parameters such as cooling and heating rates. Analysis of X-ray diffraction patterns revealed cubic structure with Pm-3m symmetry. An antiferromagnetic transition around 3.8K was observed in the pristine compound whereas doped samples showed paramagnetic nature in the whole measured temperature range.

  13. CDRA-4EU Testing in Support of ISS

    NASA Technical Reports Server (NTRS)

    Peters, Warren; Stanley, Christine; Knox, Jim

    2016-01-01

    NASA's Marshall Space Flight Center (MSFC) recently conducted tests on two desiccant beds of the four-bed molecular sieve carbon dioxide removal assembly (CDRA) returned from the International Space Station (ISS). MSFC had previously characterized the relationship between CDRA-4EU inlet conditions and the dewpoint at the desiccant bed exit and between the compressor and accumulator that make up the Carbon Dioxide Management Assembly (CDMA). MSFC installed the flight desiccant beds into the existing Exploration Test Chamber (E-chamber) using a suite of instrumentation not available on orbit to investigate the orbital performance of the desiccant beds. Test objectives, facility design and test results are presented.

  14. Interaction of Eu(III) with mammalian cells: Cytotoxicity, uptake, and speciation as a function of Eu(III) concentration and nutrient composition.

    PubMed

    Sachs, Susanne; Heller, Anne; Weiss, Stephan; Bok, Frank; Bernhard, Gert

    2015-10-01

    In case of the release of lanthanides and actinides into the environment, knowledge about their behavior in biological systems is necessary to assess and prevent adverse health effects for humans. We investigated the interaction of europium with FaDu cells (human squamous cell carcinoma cell line) combining analytical methods, spectroscopy, and thermodynamic modeling with in-vitro cell experiments under defined conditions. Both the cytotoxicity of Eu(III) onto FaDu cells and its cellular uptake are mainly concentration-dependent. Moreover, they are governed by its chemical speciation in the nutrient medium. In complete cell culture medium, i.e., in the presence of fetal bovine serum, Eu(III) is stabilized in solution in a wide concentration range by complexation with serum proteins resulting in low cytotoxicity and cellular Eu(III) uptake. In serum-free medium, Eu(III) precipitates as hardly soluble phosphate species, exhibiting a significantly higher cytotoxicity and slightly higher cellular uptake. The presence of a tenfold excess of citrate in serum-free medium causes the formation of Eu(HCit)2(3-) complexes in addition to the dominating Eu(III) phosphate species, resulting in a decreased Eu(III) cytotoxicity and cellular uptake. The results of this study underline the crucial role of a metal ion's speciation for its toxicity and bioavailability. PMID:26055652

  15. Influence of Eu doping on the microstructure and photoluminescence of CdS nanocrystals

    NASA Astrophysics Data System (ADS)

    Zhang, Kexin; Yu, Yaxin; Sun, Shuqing

    2012-07-01

    The CdS:Eu nanocrystals with a strong white emission have been synthesized by solvothemal method using ethylene glycol as solvents. From X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis it was observed that the average diameter of the CdS:Eu nanocrystals is about 5 nm. The traces of groups adsorbed on CdS:Eu nanocrystals were confirmed via FT-IR spectra. UV-visible spectroscopy study was carried out to determine the band gap of the nanocrystals and the absorbance peaks showed blue shift with respect to the bulk CdS. From photoluminescence (PL) studies at λex = 398 nm, the PL emission intensity of CdS:Eu nanocrystals enhanced by doping Eu3+ ions. In addition, the synthesis parameters including the concentration of doped Eu3+ ions, the reaction time, and the reaction temperature have influence on the optical properties of CdS:Eu nanocrystals. The charge compensation agent is a decisive factor for PL emission intensity of CdS:Eu nanocrystals. Furthermore, the storage time and condition on the fluorescence of CdS:Eu nanocrystals were also investigated.

  16. Understanding the photoluminescence characteristics of Eu3+-doped double-perovskite by electronic structure calculation

    NASA Astrophysics Data System (ADS)

    Ghosh, Binita; Halder, Saswata; Das, Sayantani; Sinha, T. P.

    2016-05-01

    Europium-doped luminescent barium samarium tantalum oxide Ba2SmTaO6 (BST) has been investigated by first-principles calculation, and the crystal structure, electronic structure, and optical properties of pure BST and Eu-doped BST have been examined and compared. Based on the calculated results, the luminescence properties and mechanism of Eu-doped BST has been discussed. In the case of Eu-doped BST, there is an impurity energy band at the Fermi level, which is formed by seven spin up energy levels of Eu and act as the luminescent centre, which is evident from the band structure calculations.

  17. Optical and structural stability of blue SrO:Eu{sup 2+} phosphor

    SciTech Connect

    Komatsu, Keiji; Nakamura, Atsushi; Ohshio, Shigeo; Toda, Ikumi; Muramatsu, Hiroyuki; Saitoh, Hidetoshi

    2013-08-15

    Chemical stability of 6-coodinated SrO is a fundamental problem when this is used for various applications. In this study, optical and chemical stabilities of 8-coordinated SrO:Eu{sup 2+} phosphor were investigated. SrO:Eu{sup 2+} phosphor was synthesized from thermal treatment of SrO:Eu powder located on a single crystalline MgO at 1500° C under reduction atmosphere. Obtained 8-coordinated SrO:Eu{sup 2+} phosphor exhibit strong blue luminescence and chemical stability in distilled water for 3 days. Our findings prove that obtained 8-coordinated SrO:Eu{sup 2+} possesses relative optical and chemical stabilities in water. - Graphical abstract: Obtained 8-coordinated SrO:Eu{sup 2+} phosphor exhibit strong blue luminescence in distilled water. Highlights: • We investigated optical and chemical stabilities of 8-coordinated SrO:Eu{sup 2+} phosphor in water. • Obtained 8-coordinated SrO:Eu{sup 2+} phosphor exhibit strong blue luminescence and chemical stability in distilled water for 3 days. • We found that the 8-coodrodinated SrO crystal structure changed to SrCO{sub 3} crystal structure after the 5 days immersion. • The obtained SrO:Eu{sup 2+} phosphor possesses high chemical stability under water, compared with commercial (6-coordinated) SrO.

  18. A luminescence study of B-type Eu2O3 under pressure

    NASA Astrophysics Data System (ADS)

    Chen, G.; Stump, N. A.; Haire, R. G.; Burns, J. B.; Peterson, J. R.

    1994-07-01

    Luminescence spectra from Eu3+ ion in B-type (monoclinic) Eu2O3 powder have been recorded at room temperature as a function of pressure using a diamond anvil cell. Changes in the spectral pattern of the Eu3+ ion emission at about 4 GPa indicated that a phase transition to the A-type (hexagonal) structure had taken place. Upon release of the applied pressure, the B-type structure was regained with hysteresis. The spectral shifts with pressure have been used to study the effect of pressure on the spin-orbit interaction of the 4f electrons in the Eu3+ ion.

  19. [VUV spectral properties of CaMgSi2O6 : Eu].

    PubMed

    Zhou, Dan; He, Da-wei; Hou, Tao

    2007-05-01

    CaMgSiOs6 : Eu samples were synthesized by a normal solid state reaction using CaCO3, MgO, SiO2 and Eu2O3 as starting materials. The properties of structure, VUV excitation and luminescence under VUV excitation were studied. CaMgSi2O6 : Eu belongs to the monoclinic space group, and the crystal structure does not change as the crystal lattice is doped with Eu ions. The emission spectra of CaMgSi2O6 : Eu3+ have revealed an intense and sharp (611 nm) red color emission from Eu3+ ((5)D0-->(7)F2) transition under 147 nm VUV excitation. The correlative data shows that the concentration quenching occurs when the Eu3+ mole concentration ranges from 0.02 to 0.10 mol. The emission spectra of CaMgSi2O6 : Eu2+ have revealed an intense and sharp (452 nm) blue color emission from Eu2+ (5d-->4f) transition under 172 nm VUV excitation. It can be seen that the intensity of the emission peak increases with increasing H3BO3 concentration. PMID:17655118

  20. Hydrothermal Synthesis, Microstructure and Photoluminescence of Eu3+-Doped Mixed Rare Earth Nano-Orthophosphates

    PubMed Central

    2010-01-01

    Eu3+-doped mixed rare earth orthophosphates (rare earth = La, Y, Gd) have been prepared by hydrothermal technology, whose crystal phase and microstructure both vary with the molar ratio of the mixed rare earth ions. For LaxY1–xPO4: Eu3+, the ion radius distinction between the La3+ and Y3+ is so large that only La0.9Y0.1PO4: Eu3+ shows the pure monoclinic phase. For LaxGd1–xPO4: Eu3+ system, with the increase in the La content, the crystal phase structure of the product changes from the hexagonal phase to the monoclinic phase and the microstructure of them changes from the nanorods to nanowires. Similarly, YxGd1–xPO4: Eu3+, Y0.1Gd0.9PO4: Eu3+ and Y0.5Gd0.5PO4: Eu3+ samples present the pure hexagonal phase and nanorods microstructure, while Y0.9Gd0.1PO4: Eu3+ exhibits the tetragonal phase and nanocubic micromorphology. The photoluminescence behaviors of Eu3+ in these hosts are strongly related to the nature of the host (composition, crystal phase and microstructure). PMID:21170409

  1. Reentrant valence transition in EuO at high pressures : beyond the bond-valence model

    SciTech Connect

    Souza-Neto, N.M.; Zhao, J.; Alp, E.; Shen, G.; Sinogeikin, S. V.; Lapertot, G.; Haskel, D.

    2012-07-12

    The pressure-dependent relation between Eu valence and lattice structure in model compound EuO is studied with synchrotron-based x-ray spectroscopic and diffraction techniques. Contrary to expectation, a 7% volume collapse at {approx}45 GPa is accompanied by a reentrant Eu valence transition into a lower valence state. In addition to highlighting the need for probing both structure and electronic states directly when valence information is sought in mixed-valent systems, the results also show that widely used bond-valence methods fail to quantitatively describe the complex electronic valence behavior of EuO under pressure.

  2. Photoluminescence of Eu³⁺-doped glasses with Cu²⁺ impurities.

    PubMed

    Jiménez, José A

    2015-06-15

    Glasses activated with Eu(3+) ions are attractive as luminescent materials for various photonic applications. Co-doping with copper has been proposed for enhancing material optical properties, but the quenching effect of Cu(2+) impurities on Eu(3+) emission in glass remains largely unexplored. In this work, Eu2O3/CuO-containing barium-phosphate glasses have been prepared by the melt-quench method, and the Eu(3+) photoluminescence (PL) quenching resulting from Eu(3+)→Cu(2+) energy transfer was evaluated. Optical absorption spectroscopy showed that with the increase in CuO concentration the Cu(2+) absorption band resonant with Eu(3+) emission (e.g. (5)D0→(7)F2 transition around 615 nm) developed steadily. As a result, Eu(3+) PL was progressively quenched. Evaluation of the quenching constants as a function of temperature in the 298-673K range showed differences basically within experimental error, consistent with a resonant transfer and lack of phonon-assisted processes. Moreover, analysis of the Eu(3+) emission decay dynamics revealed a strong correlation between the decay rates and Cu(2+) impurity levels. Results imply that for practical applications the levels of Cu(2+) in Eu(3+)/Cu(+)-activated glasses should be reduced if not removed as these will significantly limit device efficiency. PMID:25797222

  3. Basic study of Eu2+-doped garnet ceramic scintillator produced by spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Sugiyama, Makoto; Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Ito, Akihiko; Nikl, Martin; Goto, Takashi; Yoshikawa, Akira

    2012-12-01

    We report a new discovery of Eu2+-doped bulk garnet ceramic scintillators based on reduction of Eu3+ ions without additives. Eu2+-doped Y3Al5O12 and Lu3Al5O12 ceramics were prepared by spark plasma sintering (SPS) method. Using SPS, the green and blue luminescence was observed under UV lamp excitation for Eu2+-doped Y3Al5O12 and Lu3Al5O12 ceramics, respectively. Under excitation by 241Am alpha-ray the Eu2+ 5d-4f emission was observed in radioluminescence spectra both samples. For the first time, scintillation response due to Eu2+ 5d-4f luminescence was observed in the bulk garnet oxide materials. In addition, Eu-doped Al2O3 prepared by SPS showed Eu2+ 5d-4f emission in the radioluminescence spectrum. It is confirmed that Al is a key element to reduce Eu3+ as well as highly reductive condition in SPS.

  4. The magnetic structure of EuCu2Sb2

    SciTech Connect

    Ryan, D. H.; Cadogan, J. M.; Anand, V. K.; Johnston, D. C.; Flacau, R.

    2015-05-06

    Antiferromagnetic ordering of EuCu2Sb2 which forms in the tetragonal CaBe2Ge2-type structure (space group P4/nmm #129) has been studied using neutron powder diffraction and 151Eu Mössbauer spectroscopy. The room temperature 151Eu isomer shift of –12.8(1) mm/s shows the Eu to be divalent, while the 151Eu hyperfine magnetic field (Bhf) reaches 28.7(2) T at 2.1 K, indicating a full Eu2+ magnetic moment. Bhf(T) follows a smooth $S=\\frac{7}{2}$ Brillouin function and yields an ordering temperature of 5.1(1) K. Refinement of the neutron diffraction data reveals a collinear A-type antiferromagnetic arrangement with the Eu moments perpendicular to the tetragonal c-axis. As a result, the refined Eu magnetic moment at 0.4 K is 7.08(15) μB which is the full free-ion moment expected for the Eu2+ ion with $S=\\frac{7}{2}$ and a spectroscopic splitting factor of g = 2.

  5. Preparation and characterization of Eu-doped LiNbO3 films prepared by the sol-gel method

    NASA Astrophysics Data System (ADS)

    Takahashi, Makoto; Iyoda, Kazuki; Maeda, Yoshihiko; Miyauchi, Toshiyuki; Ohkido, Sadao; Sato, Shoji; Wakita, Koichi; Kajitani, Naofumi; Hotta, Kazutoshi; Kurachi, Masato

    2008-02-01

    Europium (Eu3+)-doped lithium niobate (LiNbO3) thick films were deposited on a z-cut congruent LiNbO3 (LN) substrate by the sol-gel method from 0.20moldm-3 precursor solution containing various Eu3+ concentrations and 0.10moldm-3 polyvinylalcohol, and their crystal characteristics were evaluated. The Eu3+ concentration in the LN film was controlled by the Eu3+ concentration in the starting solution. The orientation relationships between Eu3+-doped LN films and LN substrates were determined by x-ray diffraction and Raman spectroscopy, and (006) oriented Eu-doped LN epitaxial layers with parallel epitaxial relationships could be grown on the z-cut LN wafer. The refractive indices of Eu3+-doped LN films decreased with the increase of Eu3+ concentration. The luminescence intensities (D05→FJ7 emission) increased with increasing of the Eu3+ ion concentration.

  6. Structure and properties of orthoborate glasses in the Eu2O3-(Sr,Eu)O-B2O3 quaternary.

    PubMed

    Winterstein-Beckmann, Anja; Möncke, Doris; Palles, Dimitrios; Kamitsos, Efstratios I; Wondraczek, Lothar

    2015-02-19

    The structure and properties of melt-quenched glasses and partially crystallized samples from the borate series (1-2x)Eu2O3-x((Eu,Sr)O-B2O3) were investigated in the supermodified regime of x < 0.5, using Raman, infrared (IR), electron spin resonance (ESR), and UV-vis absorption and fluorescence spectroscopic techniques. ESR and optical spectroscopy showed that, despite the strongly reducing synthesis conditions, the Eu(2+)/Eu(3+) equilibrium remained shifted to the side of trivalent Eu(3+). Stable and transparent overmodified borate glasses were produced for compositions with x ≥ 0.36. Higher europium oxide concentrations resulted in precipitation of crystalline Eu2Sr3(BO3)4 and EuBO3 phases, as traced by X-ray diffraction. Raman and IR spectroscopy showed that the metaborate configuration which is present at x = 0.46 transforms gradually, with increasing Eu2O3 levels, into orthoborate [BO3](3-) triangular units. At higher europium oxide content (x ≤ 0.36), the presence of Eu(3+) supports the formation of orthoborate [BØ2O2](3-) tetrahedral species. These units organize into [B3O9](9-) rings, which exist in equilibrium with [BO3](3-) triangles. As a consequence, distinct variations can be observed also in the macroscopic properties such as density, glass transition temperature, refractive index, optical basicity, and oxygen polarizability. This observation confirms previous findings on manganese-strontium borates with high modification levels. PMID:25601494

  7. Photoluminescence and long after glow in Ba2MgSi2O7: Eu2+ and Ba2ZnSi2O7: Eu2+ phosphors

    NASA Astrophysics Data System (ADS)

    Talwar, Gurjeet J.; Moharil, S. V.; Joshi, C. P.

    2016-05-01

    Silicate phosphors doped with Eu2+ find application in solid state lighting, plasma display panel, liquid crystal display and long after glow. In present work long lasting silicate phosphors are prepared by a modified combustion synthesis. The photoluminescence spectra and long lasting decay curves are measured. The Emission wavelength of Ba2MgSi2O7: Eu2+ is observed at 500 nm for excitation 345 nm.The emission wavelength of Ba2ZnSi2O7: Eu2+ is obtained at 496 nm at excitation 350 nm. Decay constants are calculated for both the phosphors.

  8. Optically stimulated luminescence (OSL) response of Al2O3:C, BaFCl:Eu and K2Ca2(SO4)3:Eu phosphors.

    PubMed

    Kumar, Pratik; Bahl, Shaila; Sahare, P D; Kumar, Surender; Singh, Manveer

    2015-12-01

    This paper investigates the optically stimulated luminescence (OSL) response of BaFCl:Eu and K2Ca2(SO4)3:Eu phosphors for different doses and bleaching durations. The results have also been compared with the commercially available Landauer Al2O3:C (Luxel®) dosemeter. Nanocrystalline K2Ca2(SO4)3:Eu is known to be a sensitive thermoluminescent phosphor, but its OSL response is hardly reported. At first, pellets of nanocrystalline K2Ca2(SO4)3:Eu powder were prepared by adding Teflon as a binder. Their OSL signal was compared with that of the material in pure form, i.e. without adding the binder (in 100:1 ratio). It was observed that adding the binder does not appreciably affect the OSL intensity. On comparison with the commercially available Al2O3:C from Landauer, it was found that K2Ca2(SO4)3:Eu is around 15 times less sensitive than Al2O3:C. 'Homemade' BaFCl:Eu phosphor has also been studied. The intensity of BaFCl:Eu was ∼20 times more than the standard Al2O3:C dosemeter and ∼200 times more sensitive than K2Ca2(SO4)3:Eu in the dose range of 13-200 cGy. OSL dosemeters are believed to give luminescence signal even if they are read before, i.e. multiple reading may be possible under suitable conditions after single exposure. This was also checked for all the prepared dosemeters and it was found that Al2O3:C showed the least decrease of <2 %, followed by BaFCl:Eu of 15 % and K2Ca2(SO4)3:Eu with 20 %. Finally, Al2O3:C and BaFCl:Eu phosphors were also studied for their optical bleaching durations to which the respective signals get completely removed so that the phosphor can be re-used. It was observed that BaFCl:Eu is bleached faster and more easily than Al2O3:C. PMID:25646524

  9. Effect of shock compression on optical and structural properties of Eu2O3 and Y2O3:Eu3+ powders

    NASA Astrophysics Data System (ADS)

    Kishimura, Hiroaki; Hamada, Sho; Aruga, Atsushi; Matsumoto, Hitoshi

    2016-05-01

    Shock-recovery experiments on Eu2O3 and Y2O3:Eu3+ powders using a metal plate projectile accelerated by a single-stage powder-propellant gun were performed to investigate phase stability and response at high pressures and temperatures. The recovered samples were characterized using powder X-ray diffraction analysis and photoluminescence spectroscopy. The onset of the structural phase transition from the cubic (C-type) to monoclinic (B-type) phase was observed for both Eu2O3 and Y2O3:Eu3+ powders at shock pressures of 8 and 13 GPa, respectively. For Eu2O3, the amount of B-type phase increases with increasing shock pressure up to 23 GPa, whereas for Y2O3:Eu3+, a maximum was reached at 25 GPa followed by a decrease with increasing shock pressure; only the C-type phase was detected in the sample shocked at 51 GPa. The change in the amount of B-type phase indicates stability for the monoclinic phase against shock-induced heat and mechanical deformation. The large range in shock pressure for which the C-type and B-type phases coexist in Eu2O3 and Y2O3:Eu3+ indicates that the pressure-induced phase transition is too sluggish to be completed within the shock duration. The D 5 0→ 7 F 2 / 5 D 0 → 7 F 1 intensity ratios for the shock-recovered Eu2O3 and Y2O3:Eu3+ samples were independent of the shock pressure and the amount of C-type phase in the samples. No relationship was observed between the crystal-field parameter B20 and the amount of C-type phase in both shock-recovered samples. However, with increasing B 20 2 , the D 5 0→ 7 F 2 / 5 D 0 → 7 F 1 intensity ratio decreased, whereas the D 5 0→ 7 F 0 / 5 D 0 → 7 F 1 intensity ratio increased. These results suggest that shock-induced deformation leads to enhanced J-mixing in both the Eu2 O3 and the Y2O3:Eu3+ samples.

  10. Is EU/EEA population protected from polio?

    PubMed Central

    Nijsten, DRE; Carrillo-Santisteve, P; Miglietta, A; Ruitenberg, J; Lopalco, PL

    2015-01-01

    The WHO European Region has been declared polio-free since 2002. By 2010, inactivated polio vaccine (IPV) was the only polio vaccine in use in the EU/EEA for the primary vaccination of children. A systematic review of the literature on polio seroprevalence studies, complemented by the analysis of available vaccine coverage data, has been carried out with the aim of assessing the level of protection against polio in the European population. A total of 52 studies, with data from 14 out of the 31 EU/EEA countries, were included in the analysis. This systematic review shows that, overall, seroprevalence for PV1 and PV3 is high in most countries, although seroimmunity gaps have been detected in several birth cohorts. In particular, relatively low immunity status was found in some countries for individuals born in the 60's and 70's. Discrepancies between reported vaccination coverage and immunity levels have been also highlighted. Countries should make sure that their population is being vaccinated for polio to reduce the risk of local poliovirus transmission in case of importation. Moreover, assessing immunity status should be priority for those traveling to areas where wild polioviruses are still circulating. PMID:25898095