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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. Preliminary engineering assessment of the HCLL and HCPB Neutron Activation System

    SciTech Connect

    Calderoni, Pattrick; Leichtle, Dieter; Angelone, Maurizio; Klix, Axel

    2015-07-01

    The Neutron Activation System (NAS) is one of the four types of neutronics sensors considered for the testing of the HCLL and HCPB Test Blanket Module (TBM) in ITER. It measures the absolute neutron flux intensity with information on the neutron spectrum in selected positions of the TBM. The working principle of the NAS is as follows: the system moves small activation probes (capsules) into selected positions in the TBM (irradiation ends) by means of pneumatic transport with pressurized helium gas; the capsules are irradiated for a selected period, depending on their materials composition (several tens of seconds up to the full plasma pulse length); immediately after the irradiation they are extracted and transported to a gamma spectrometer by means of the same pneumatic transport system; the gamma spectrometer determines the induced gamma activity; the neutron flux and neutron fluence is calculated from the measured gamma activity and the known activation cross section of the materials in the activation probe; after the measurement the capsule is sent either to a disposal or storage (for later measurement). This paper summarizes the results of the feasibility assessment of the TBM NAS in the conceptual design phase, including design justification, identification of requirements based on the expected operating conditions in ITER and preliminary engineering assessment of the activation materials, irradiation ends integration in the modules design and the counting station. (authors)

  3. General Motors TBM-1 Avenger (Grumman TBF)

    NASA Technical Reports Server (NTRS)

    1943-01-01

    General Motors TBM-1 Avenger (Grumman TBF): In an effort to relieve pressure from over-worked Grumman Aircraft and put idle automobile factories to work, Grumman TBF Avengers were built by the Eastern Aircraft Division of General Motors as the TBM Avenger. This is a General Motors example of the TBM-1.

  4. 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.

  5. Neutron Measurement Instrumentation Development at KIT for the European ITER TBM

    SciTech Connect

    Klix, A.; Fischer, U.; Raj, P.; Reimann, Th.; Szalkai, D.; Tian, K.; Angelone, M.; Gehre, D.; Lyoussi, A.

    2015-07-01

    SPND which would be sensitive also to the fast neutron flux expected in the TBMs. To this end simulations were done with the European Activation System EASY and neutron flux spectra which were calculated with MCNP for the HCPB TBM. Preliminary tests with commercial SPND in a fast reactor were performed. As a result of these activities, several materials have been found which may be suitable for the measurement of fast neutron fluxes in the TBM. Test detectors are under preparation for testing with DT neutron generators. Within the I{sub S}MART project, funded by KIC InnoEnergy, KIT is developing an online detector based on silicon carbide electronics for the TBMs. The operation of such detectors at TBM relevant temperatures is expected to incur lower accumulated radiation damage to them than at room temperature due to annealing effects. Detectors of several designs have been already irradiated with DT neutrons. Irradiation tests at elevated temperatures have been done and further tests are currently underway. This paper summarizes the status of the work for these three neutron flux monitor systems. (authors)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Diagnostic accuracy of a uniform research case definition for TBM in children: a prospective study.

    PubMed

    Solomons, R S; Visser, D H; Marais, B J; Schoeman, J F; van Furth, A M

    2016-07-01

    Bacteriological confirmation of tuberculous meningitis (TBM) is problematic, and rarely guides initial clinical management. A uniform TBM case definition has been proposed for research purposes. We prospectively enrolled patients aged 3 months to 13 years with meningitis confirmed using cerebrospinal fluid analysis at Tygerberg Hospital, Cape Town, South Africa. Criteria that differentiated TBM from other causes were explored and the accuracy of a probable TBM score assessed by comparing bacteriologically confirmed cases to 'non-TBM' controls. Of 139 meningitis patients, 79 were diagnosed with TBM (35 bacteriologically confirmed), 10 with bacterial meningitis and 50 with viral meningitis. Among those with bacteriologically confirmed TBM, 15 were Mycobacterium tuberculosis culture-positive and 20 were culture-negative but positive on GenoType(®) MTBDRplus or Xpert(®) MTB/RIF; 18 were positive on only a single commercial nucleic acid amplification test. A probable TBM score provided a sensitivity of 74% (95%CI 57-88) and a specificity of 97% (95%CI 86-99) compared to bacteriologically confirmed TBM. A probable TBM score demonstrated excellent specificity compared to bacteriological confirmation. However, 26% of children with TBM would be missed due to the limited accuracy of the case definition. Further prospective testing of an algorithm-based approach to TBM is advisable before recommendation for general clinical practice.

  12. 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.

  13. 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.

  14. Regression Models and Fuzzy Logic Prediction of TBM Penetration Rate

    NASA Astrophysics Data System (ADS)

    Minh, Vu Trieu; Katushin, Dmitri; Antonov, Maksim; Veinthal, Renno

    2017-03-01

    This paper presents statistical analyses of rock engineering properties and the measured penetration rate of tunnel boring machine (TBM) based on the data of an actual project. The aim of this study is to analyze the influence of rock engineering properties including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), rock brittleness index (BI), the distance between planes of weakness (DPW), and the alpha angle (Alpha) between the tunnel axis and the planes of weakness on the TBM rate of penetration (ROP). Four (4) statistical regression models (two linear and two nonlinear) are built to predict the ROP of TBM. Finally a fuzzy logic model is developed as an alternative method and compared to the four statistical regression models. Results show that the fuzzy logic model provides better estimations and can be applied to predict the TBM performance. The R-squared value (R2) of the fuzzy logic model scores the highest value of 0.714 over the second runner-up of 0.667 from the multiple variables nonlinear regression model.

  15. 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.

  16. 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.

  17. 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.

  18. Airborne validation of an IR passive TBM ranging sensor

    NASA Astrophysics Data System (ADS)

    McKay, Dennis L.; Wohlers, Martin R.; Chuang, Chiu-Kuang; Draper, James S.; Walker, James

    1999-07-01

    Monocular Passive Ranging (MPR) employs a single multicolor IR sensor to passively range to a boosting theater ballistic missile (TBM). Airborne active ranging sensor, such as radars and ladars, may attract anti-radiation missiles, and are forced to large standoff distances. Thus, they may not be positioned to give adequate early warning of a missile launch, Estimation of launch position, or prediction of impact points. Ground based radars may not 'see' sufficiently over the horizon. In contrast, an MPR sensor can be deployed close to or within denied enemy territory and remain covert to observe a TBM as early as its launch, to discriminate and track the TBM target, and to provide very timely and accurate reports on launch position, predicted flight and impact positions. A passive sensor can be in a small package, have low weight, low power, relatively low cost, and be readily adaptable to airborne and spaceborne platforms. This paper discusses an airborne data collection program to demonstrate useful MPR accuracy to boosting TBMs. Engineering and sensors performance tradeoffs, and range error budgets are discussed.

  19. An overview of the US DCLL ITER-TBM program

    SciTech Connect

    Wong, C. P. C.; Abdou, M.; Dagher, M.; Katoh, Y.; Kurtz, R. J.; Malang, S.; Marriott, E. P.; Merrill, B. J.; Messadek, K.; Morley, N. B.; Sawan, M. E.; Sharafat, S.; Smolentsev, S.; Sze, D. K.; Willms, S.; Ying, A.; Youssef, M. Z.

    2010-12-01

    Under the US Fusion Nuclear Science and Technology program, we selected the Dual Coolant Lead Lithium (DCLL) concept as our primary Test Blanket Module (TBM) for testing in ITER. The DCLL blanket concept has the potential to be a high-performance DEMO blanket design with a projected thermal efficiency of >40%. Reduced activation ferritic/martensitic (RAF/M) steel is used as the structural material. Helium is used to cool the first wall and blanket structure, and the self-cooled Pb-17Li breeder is circulated for power conversion and for tritium extraction. A SiC-based flow channel insert (FCI) is used as an electrical insulator for magnetohydrodynamic pressure drop reduction from the circulating Pb-17Li and as a thermal insulator to separate the high-temperature Pb-17Li (~650–700 °C) from the RAF/M structure, which has a corrosion temperature limit of ~480 °C. The RAF/M material must also operate at temperatures above 350 °C but less than 550 °C. We are continuing the development of the mechanical design and performing neutronics, structural and thermal hydraulics analyses of the DCLL TBM module. Prototypical FCI structures were fabricated and further attention was paid to MHD effects and the design of the inboard blanket for DEMO. We are also making progress on related R&D needs to address key areas. Finally, this paper is a summary report on the progress and results of recent DCLL TBM development activities.

  20. An Overview of the US DCLL ITER-TBM Program

    SciTech Connect

    C.P.C. Wong; M. Abdou; M. Dagher; Y. Katoh; B. J. Merrill

    2010-12-01

    Under the US Fusion Nuclear Science and Technology program, we selected the Dual Coolant Lead Lithium (DCLL) concept as our primary Test Blanket Module (TBM) for testing in ITER. The DCLL blanket concept has the potential to be a high-performance DEMO blanket design with a projected thermal efficiency of >40%. Reduced activation ferritic/martensitic (RAF/M) steel is used as the structural material. Helium is used to cool the first wall and blanket structure, and the self-cooled Pb-17Li breeder is circulated for power conversion and for tritium extraction. A SiC-based flow channel insert (FCI) is used as an electrical insulator for magnetohydrodynamic pressure drop reduction from the circulating Pb-17Li and as a thermal insulator to separate the high-temperature Pb-17Li (650–700 °C) from the RAF/M structure, which has a corrosion temperature limit of 480 °C. The RAF/M material must also operate at temperatures above 350 °C but less than 550 °C. We are continuing the development of the mechanical design and performing neutronics, structural and thermal hydraulics analyses of the DCLL TBM module. Prototypical FCI structures were fabricated and further attention was paid to MHD effects and the design of the inboard blanket for DEMO. We are also making progress on related R&D needs to address key areas. This paper is a summary report on the progress and results of recent DCLL TBM development activities.

  1. 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

  2. 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.

  3. Verification of design rules for EUROFER under TBM operating conditions

    NASA Astrophysics Data System (ADS)

    Sunyk, R.; Aktaa, J.

    2007-08-01

    The aim of the activity presented in this work is, firstly, an evaluation of existing design rules considered for austenitic steels exhibiting cycle-by-cycle hardening, in contrast to the reduced-activation ferritic-martensitic steels (RAFM), which soften under cyclic loading. Secondly, we are aimed in a definition of the range of operating temperatures and loads for the current design of the test blanket module (TBM). Results of cycling tests of the EUROFER 97 have been thereby used to adjust material parameters needed for an ABAQUS-own combined non-linear isotropic-kinematic hardening model. Furthermore, a visco-plastic material model considering material damage and implemented recently as an ABAQUS user material (UMAT) has been also applied for simulations. Some important design rules within the elastic route have been evaluated and their predictions have been compared to results of cyclic simulations using the advanced material models mentioned above.

  4. 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.

  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. Measures for characterizing directionality specific volume changes in TBM of brain growth

    PubMed Central

    Rajagopalan, Vidya; Scott, Julia; Habas, Piotr A.; Kim, Kio; Corbett-Detig, James; Rousseau, Francois; Glenn, Orit A.; Barkovich, A. James; Studholme, Colin

    2012-01-01

    Tensor based morphology (TBM) is a powerful approach to analyze local structural changes in brain anatomy. However, conventional scalar TBM methods are unable to present direction-specific analysis of volume changes required to model complex changes such as those during brain growth. In this paper, we describe novel TBM descriptors for studying direction-specific changes in a subject population which can be used in conjunction with scalar TBM to analyze local patterns in directionality of volume change during brain development. We illustrate the use of these methods by studying brain developmental patterns in fetuses. Results show that this approach detects early changes local growth that are related to the early stages of sulcal and gyral formation. PMID:20879333

  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. LOFA analysis in helium and Pb-Li circuits of LLCB TBM by FE simulation

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Paritosh; Ranjithkumar, S.; Sharma, Deepak; Danani, Chandan

    2017-04-01

    One of the main ITER objectives is to demonstrate the feasibility of the breeding blanket concepts that would lead to tritium self-sufficiency and the extraction of a high-grade heat for electricity production. India has developed the LLCB TBM to be tested in ITER for the validation of design concepts for tritium breeding blankets relevant DEMO and future power reactor. LLCB concept has the unique features of combination of both solid (lithium titanate as packed pebble bed) and liquid breeders (molten lead lithium). India specific IN-RAFMS is the structural material for TBM. The First Wall is actively cooled by high-pressure helium (He) gas [1]. It is important to validate the design of TBM to withstand various loads acting on it including accident analysis like LOCA, LOFA etc. Detailed thermal-hydraulic simulation studies including LOFA in helium and Pb-Li circuits of LLCB TBM have been performed using Finite Element using ANSYS. These analyses will provide important information about the temperature distribution in different materials used in TBM during steady state and transient condition. Thermal-hydraulic safety requirement has also been envisaged for the initiation the FPPS (Fusion Power Shutdown System) during LOFA. All these analysis will be presented in detail in this paper.

  9. 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.

  10. GalaxyTBM: template-based modeling by building a reliable core and refining unreliable local regions.

    PubMed

    Ko, Junsu; Park, Hahnbeom; Seok, Chaok

    2012-08-10

    Protein structures can be reliably predicted by template-based modeling (TBM) when experimental structures of homologous proteins are available. However, it is challenging to obtain structures more accurate than the single best templates by either combining information from multiple templates or by modeling regions that vary among templates or are not covered by any templates. We introduce GalaxyTBM, a new TBM method in which the more reliable core region is modeled first from multiple templates and less reliable, variable local regions, such as loops or termini, are then detected and re-modeled by an ab initio method. This TBM method is based on "Seok-server," which was tested in CASP9 and assessed to be amongst the top TBM servers. The accuracy of the initial core modeling is enhanced by focusing on more conserved regions in the multiple-template selection and multiple sequence alignment stages. Additional improvement is achieved by ab initio modeling of up to 3 unreliable local regions in the fixed framework of the core structure. Overall, GalaxyTBM reproduced the performance of Seok-server, with GalaxyTBM and Seok-server resulting in average GDT-TS of 68.1 and 68.4, respectively, when tested on 68 single-domain CASP9 TBM targets. For application to multi-domain proteins, GalaxyTBM must be combined with domain-splitting methods. Application of GalaxyTBM to CASP9 targets demonstrates that accurate protein structure prediction is possible by use of a multiple-template-based approach, and ab initio modeling of variable regions can further enhance the model quality.

  11. 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.

  12. 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.

  13. Design of the helium cooled lithium lead breeding blanket in CEA: from TBM to DEMO

    NASA Astrophysics Data System (ADS)

    Aiello, G.; Aubert, J.; Forest, L.; Jaboulay, J.-C.; Li Puma, A.; Boccaccini, L. V.

    2017-04-01

    The helium cooled lithium lead (HCLL) blanket concept was originally developed in CEA at the beginning of 2000: it is one of the two European blanket concepts to be tested in ITER in the form of a test blanket module (TBM) and one of the four blanket concepts currently being considered for the DEMOnstration reactor that will follow ITER. The TBM is a highly optimized component for the ITER environment that will provide crucial information for the development of the DEMO blanket, but its design needs to be adapted to the DEMO reactor. With respect to the TBM design, reduction of the steel content in the breeding zone (BZ) is sought in order to maximize tritium breeding reactions. Different options are being studied, with the potential of reaching tritium breeding ratio (TBR) values up to 1.21. At the same time, the design of the back supporting structure (BSS), which is a DEMO specific component that has to support the blanket modules inside the vacuum vessel (VV), is ongoing with the aim of maximizing the shielding power and minimizing pumping power. This implies a re-engineering of the modules’ attachment system. Design changes however, will have an impact on the manufacturing and assembly sequences that are being developed for the HCLL-TBM. Due to the differences in joint configurations, thicknesses to be welded, heat dissipation and the various technical constraints related to the accessibility of the welding tools and implementation of non-destructive examination (NDE), the manufacturing procedure should be adapted and optimized for DEMO design. Laser welding instead of TIG could be an option to reduce distortions. The time-of-flight diffraction (TOFD) technique is being investigated for NDE. Finally, essential information expected from the HCLL-TBM program that will be needed to finalize the DEMO design is discussed.

  14. Neutronics experiments for uncertainty assessment of tritium breeding in HCPB and HCLL blanket mock-ups irradiated with 14 MeV neutrons

    NASA Astrophysics Data System (ADS)

    Batistoni, P.; Angelone, M.; Fischer, U.; Klix, A.; Kodeli, I.; Leichtle, D.; Pillon, M.; Pohorecki, W.; Villari, R.

    2012-08-01

    Two neutronics experiments have been carried out at 14 MeV neutron sources on mock-ups of the helium cooled pebble bed (HCBP) and the helium cooled lithium lead (HCLL) variants of ITER test blanket modules (TBMs). These experiments have provided an experimental validation of the calculations of the tritium production rate (TPR) in the two blanket concepts and an assessment of the uncertainties due to the uncertainties on nuclear data. This paper provides a brief summary of the HCPB experiment and then focuses in particular on the final results of the HCLL experiment. The TPR has been measured in the HCLL mock-up irradiated for long times at the Frascati 14 MeV Neutron Generator (FNG). Redundant and well-assessed experimental techniques have been used to measure the TPR by different teams for inter-comparison. Measurements of the neutron and gamma-ray spectra have also been performed. The analysis of the experiment, carried out by the MCNP code with FENDL-2.1 and JEFF-3.1.1 nuclear data libraries, and also including sensitivity/uncertainty analysis, shows good agreement between measurements and calculations, within the total uncertainty of 5.9% at 1σ level.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. Discrete/Finite Element Modelling of Rock Cutting with a TBM Disc Cutter

    NASA Astrophysics Data System (ADS)

    Labra, Carlos; Rojek, Jerzy; Oñate, Eugenio

    2017-03-01

    This paper presents advanced computer simulation of rock cutting process typical for excavation works in civil engineering. Theoretical formulation of the hybrid discrete/finite element model has been presented. The discrete and finite element methods have been used in different subdomains of a rock sample according to expected material behaviour, the part which is fractured and damaged during cutting is discretized with the discrete elements while the other part is treated as a continuous body and it is modelled using the finite element method. In this way, an optimum model is created, enabling a proper representation of the physical phenomena during cutting and efficient numerical computation. The model has been applied to simulation of the laboratory test of rock cutting with a single TBM (tunnel boring machine) disc cutter. The micromechanical parameters have been determined using the dimensionless relationships between micro- and macroscopic parameters. A number of numerical simulations of the LCM test in the unrelieved and relieved cutting modes have been performed. Numerical results have been compared with available data from in-situ measurements in a real TBM as well as with the theoretical predictions showing quite a good agreement. The numerical model has provided a new insight into the cutting mechanism enabling us to investigate the stress and pressure distribution at the tool-rock interaction. Sensitivity analysis of rock cutting performed for different parameters including disc geometry, cutting velocity, disc penetration and spacing has shown that the presented numerical model is a suitable tool for the design and optimization of rock cutting process.

  2. Preparation and analysis of helium purge gas mixture to be used in Tritium Extraction System of LLCB TBM

    NASA Astrophysics Data System (ADS)

    Gayathri Devi, V.; Yadav, Deepak; Sircar, Amit

    2017-04-01

    Hydrogen isotopes are extracted from the Ceramic Breeder (CB) and liquid Lead Lithium (Pb-Li) breeder of Lead Lithium Ceramic Breeder (LLCB) Test Blanket Module (TBM) with Helium purge gas. 1000 ppm of hydrogen gas is mixed with the purge helium gas to facilitate improved extraction of hydrogen isotopes from the breeder zones by hydrogen swamping reactions [1]. An experimental set up is developed for making up the purge gas mixture with a composition similar to the purge gas composition to be used for extraction of hydrogen isotopes from CB and Pb-Li of LLCB TBM. This is achieved by introducing different ppm levels (1000 - 5000 ppm) of hydrogen in helium gas by flow control mechanism. The analysis of the purge gas mixture is performed using a highly sensitive Gas Chromatography (GC) system. This paper describes the detailed design of the experimental set-up and results for the analysis of different concentrations of hydrogen in helium purge gas.

  3. 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.

  4. Raman and crystal field studies of Tb-O bonds in TbM n2O5

    NASA Astrophysics Data System (ADS)

    Mansouri, S.; Jandl, S.; Balli, M.; Laverdière, J.; Fournier, P.; Dimitrov, D. Z.

    2016-09-01

    We have studied the temperature dependence of TbM n2O5 Raman-active phonons and its T b3 + crystal field (CF) excitations. Interestingly, the Raman intensities of some phonons are significantly reduced below ˜180 K . Such behaviors are also observed in HoM n2O5 and YM n2O5 systems. A connection between the Raman intensities and the nearest-neighbor mean-square relative displacement σ2 is established. Also, some of the T b3 + and H o3 + CF excitations become broader below ˜180 K . These results are discussed in terms of the disorder induced by the Tb-O bond splitting.

  5. A Wear Rule and Cutter Life Prediction Model of a 20-in. TBM Cutter for Granite: A Case Study of a Water Conveyance Tunnel in China

    NASA Astrophysics Data System (ADS)

    Liu, Quansheng; Liu, Jianping; Pan, Yucong; Zhang, Xiaoping; Peng, Xingxin; Gong, Qiuming; Du, Lijie

    2017-05-01

    Disc cutter wear is one of the comprehensive results of the rock-machine interaction in tunnel boring machine (TBM) tunneling. The replacement of the disc cutter is a time-consuming and costly activity that can significantly reduce the TBM utilization ( U) and advance rate (AR), and has a major effect on the total time and cost of TBM tunneling projects. Therefore, the importance of predicting the cutter life accurately can never be overemphasized. Most cutter wear prediction models are only suitable for 17-in. or smaller disc cutters. However, use of large-diameter disc cutters has been an irresistible trend for large-section hard rock TBMs. This study attempts to reveal the genuine wear rule of a 20-in. disc cutter and develop a new empirical model for predicting the cutter life in granite based on field data collected from a water conveyance tunnel constructed by the TBM tunneling method in China. The field data including the actual cutter wear and the geological parameters along the studied tunnel were compiled in a special database that was subjected to statistical analysis to reveal the genuine wear rule of a 20-in. disc cutter and develop the reasonable correlations between some common intact rock parameters and the disc cutter life. These equations were developed based on data from massive to very massive granite with a UCS range of 40-100 MPa, which can be applied for the assessment of the cutter life of a 20-in. disc cutter in similar hard rock projects with similar rock strengths and rock abrasivities.

  6. Free-face-Assisted Rock Breaking Method Based on the Multi-stage Tunnel Boring Machine (TBM) Cutterhead

    NASA Astrophysics Data System (ADS)

    Geng, Qi; Wei, Zhengying; Meng, Hao; Macias, Francisco Javier; Bruland, Amund

    2016-11-01

    In order to improve the rock breaking efficiency of hard rock tunnel boring, many innovative rock breaking methods have been proposed (e.g., the water jet cutting, the high-power laser cutting, the impact-rotary drilling, and the undercutting method). However, most of the methods are not applicable to TBMs due to some structural reasons. Aiming on this problem, a free-face-assisted rock breaking method based on the multi-stage TBM cutterhead has been proposed. Series of proof-of-concept tests includes (1) the static compression test with vertical free face and (2) the rotary cutting tests in different free surface conditions were designed and carried out. The results show that the rock breaking force and efficiency can be significantly reduced and improved, respectively, with the assistance of the free face, due to the failure of the rock close to the free face is tensile-dominated failure. The influencing distance of the free face in the radial direction is at least 330 mm which covers about 5 disk cutters. Finally, the general structure of a small two-stage cutterhead (4 m in diameter) was tentatively designed in order to provide a possible approach to apply the free-face effect to TBMs.

  7. A Study of Optimal Rock-Cutting Conditions for Hard Rock TBM Using the Discrete Element Method

    NASA Astrophysics Data System (ADS)

    Moon, T.; Oh, J.

    2012-09-01

    The efficiency of TBM performance affected by the specific s/p ( s: spacing and p: penetration) ratio of the disc cutter is a research issue in demand. This article presents a multi-indentation simulation using discrete element method (DEM) analysis to study the optimal rock-cutting phenomena in terms of the interaction of the s/p ratio with intact rock properties. The multi-indentation simulation attempts to represent a linear cutting machine (LCM) test, which is a full-scale test for evaluating the optimal rock-cutting condition and measuring required reaction forces based on the intact rock condition in general practice. A governing equation relating mechanical rock properties with geometric characteristics for the optimal rock-cutting condition is derived by the numerical simulation, and its performance is evaluated with the result of the laboratory LCM tests. The results of simulations and real LCM tests show that the effective rock-cutting condition corresponding to the minimum specific energy can be estimated by an optimized s/p ratio, which, in turn, is linearly proportional to the square of the material brittleness, B 2, and cutter tip width, t (i.e., s/ p = cB 2 t, where c is coefficient). The limitation of the numerical simulation associated with the sample preparation is also discussed.

  8. 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

  9. 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)

  10. 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.

  11. EU Cadzie project

    NASA Astrophysics Data System (ADS)

    Naaim, M.

    2009-04-01

    The CADZIE project received nearly € 700,000 funding under the energy, environment and sustainable development section of the Fifth Framework Programme (FP5). Several scientists from France, Italy, Norway, Austria, Iceland and Switzerland were involved in this initiative, under the co-ordination of the Cemagref institute in Grenoble, France. The initiative was created in response to the extreme avalanche winter of 1999, during which 83 people were killed across Europe. Avalanche protection relies on two key processes: structural measures such as building defence structures to stop and / or contain the avalanche flow and non structural measures such as zoning the exposed areas. The consortium investigated these two areas in order to improve overall protection methods. This EU-funded collaboration has led to the development of more accurate methods for mapping and protection design.

  12. 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.

  13. New EU regulations in endoscopy.

    PubMed

    Wächter, M; Diekjobst, T

    1995-09-01

    As a result of European unification, new regulations valid within the territory of the European Union (EU) have been negotiated and published. As in other medical fields, the Medical Device Directive (MDD) is the most important new regulation and also effects endoscopy. In a transition period until June 1998, the MDD will be transposed into national law by the member states of the EU. Compliance with the MDD and other European regulations is indicated by the CE mark affixed to the product.

  14. 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.

  15. Optical properties of Eu(2+) /Eu(3+) mixed valence phosphor Ca2 SiO2 F2 :Eu(2+) /Eu(3).

    PubMed

    Xie, Mubiao; Zhu, Guoxian; Pan, Rongkai; Xie, Wei

    2017-04-19

    The Eu(2+) /Eu(3+) mixed valence phosphor Ca2 SiO2 F2 :Eu(2+) /Eu(3+) was prepared using a solid-state reaction synthesis method in a CO atmosphere, and the optical properties were investigated. The spectroscopic properties revealed that Ca(2+) ions were occupied by both Eu(2+) and Eu(3+) ions in Ca2 SiO2 F2 , and both ions were able to generate their characteristic emissions. A broad 5d → 4f Eu(2+) band at ~470 nm and narrow 4f → 4f Eu(3+) peaks upon excitation with n-UV light were observed. The ratio between Eu(2+) and Eu(3+) emissions changed regularly, and the relative intensity of the red component from Eu(3+) became systematically stronger with increasing overall Eu content. As a result, the emission color of these phosphors can be tunable from blue to pink under n-UV light excitation. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Governance in EU illicit drugs policy.

    PubMed

    Edwards, Carel; Galla, Maurice

    2014-09-01

    This commentary represents the authors' views on EU governance in illicit drug policy, a field in which they were active for more than 10 years between them. EU drug policy has a narrow legal basis in the European Treaties and is mostly non-binding. The main policy instruments are 8-year EU Drug Strategies, underpinned by 4-year Action Plans which set out specific objectives at national, EU or international level. The approach that guides EU drug policy is known as the 'balanced approach'. It is remarkably restrained and reflects the reality that very few Member States have either the socio-political culture or the resources to consistently apply the punitive sanctions foreseen by the UN conventions. An important feature of EU governance in the field of drugs is the proactive support that is provided to non-governmental organisations both within the EU as well as in accession, associated or third countries. At a global level, the EU is a major financial aid donor also in this field. This position is not however reflected in corresponding political clout for the EU within the UN system. EU governance on drugs has made it possible for many of its Member States to accommodate the problem rather than to "solve" what by all the evidence from the last 100 years may well be insoluble, at least by means of criminalisation and prohibition. The big question is where EU drug policy is headed in the next few years. The EU has been promoting measures and practices that target real problems. It has done so without indulging too much in unhelpful rhetoric. However, like all successful formulae this one also has a sell-by date. EU governance in the field of drugs cannot afford to stand still. It needs to find a second wind.

  17. Intensified treatment with high dose rifampicin and levofloxacin compared to standard treatment for adult patients with tuberculous meningitis (TBM-IT): protocol for a randomized controlled trial.

    PubMed

    Heemskerk, Dorothee; Day, Jeremy; Chau, Tran Thi Hong; Dung, Nguyen Huy; Yen, Nguyen Thi Bich; Bang, Nguyen Duc; Merson, Laura; Olliaro, Piero; Pouplin, Thomas; Caws, Maxine; Wolbers, Marcel; Farrar, Jeremy

    2011-02-02

    , respectively (corresponding to a target hazard ratio of 0.7), a power of 80% and a two-sided significance level of 5%. Randomization ratio is 1:1. The primary endpoint is overall survival, i.e. time from randomization to death during a follow-up period of 9 months. Secondary endpoints are: neurological disability at 9 months, time to new neurological event or death, time to new or recurrent AIDS-defining illness or death (in HIV-positive patients only), severe adverse events, and rate of treatment interruption for adverse events. Currently very few options are available for the treatment of TBM and the mortality rate remains unacceptably high with severe disabilities seen in many of the survivors. This trial is based on the hypothesis that current anti-mycobacterial treatment schedules for TBM are not potent enough and that outcomes will be improved by increasing the CSF penetrating power of this regimen by optimising dosage and using additional drugs with better CSF penetration. International Standard Randomised Controlled Trial Number ISRCTN61649292.

  18. Contribution of Eu 4f states to the magnetic anisotropy of EuO

    SciTech Connect

    Arenholz, E.; Schmehl, A.; Schlom, D.G.; van der Laan, G.

    2008-09-11

    Anisotropic x-ray magnetic linear dichroism (AXMLD) provides a novel element-, site-, shell-, and symmetry-selective techniques to study the magnetic anisotropy induced by a crystalline electric field. The weak Eu2+ M4,5 AXMLD observed in EuO(001) indicates that the Eu 4f states are not rotationally invariant and hence contribute weakly to the magnetic anisotropy of EuO. The results are contrasted with those obtained for 3d transition metal oxides.

  19. 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.

  20. Education of EU Migrant Children in EU Member States. Research Report

    ERIC Educational Resources Information Center

    Harte, Emma; Herrera, Facundo; Stepanek, Martin

    2016-01-01

    This policy brief looks at the education of EU migrant children in the context of intra-EU mobility. It examines some of the literature and data on the topic in order to identify key differences between EU migrant children and non-migrant children. There are disparities in educational performance between migrants and non-migrants. The brief…

  1. Calibration of the EU Oxybarometer for Nakhlites

    NASA Technical Reports Server (NTRS)

    Makishima, J.; McKay, G.; Le, L.; Miyamoto; Mikouchi, T.

    2006-01-01

    Martian meteorites have various characteristics, which are direct clues to understanding the petrogenesis of Mars rocks. The variation in oxidation state among the Martian meteorites must have important implications for redox conditions of the Martian crust/mantle and overall differentiation on Mars. Wadhwa [1] and Herd et al. [2] reported that Martian basalts were formed under a range of oxidation states, suggesting complex petrogenesis processes. The nakhlites, which have rather different characteristics from basaltic shergottites, may give us additional clues to Martian petrogenesis. The oxidation states of meteorites are usually described by the oxygen fugacity (fO2) under which the meteorites crystallized. One of the methods to estimate the oxygen fugacity is the depth of Eu anomaly. Eu(2+)/Eu(3+) is determined by the oxygen fugacity and partitioning is different for Eu(2+) and Eu(3+). Therefore, the depth of Eu anomaly in a mineral is a function of the oxygen fugacity and the Eu2+/Eu3+ in the melt from which the mineral crystallized. This method has some advantages over another major method, the two-oxide oxybarometer [3], which can more easily be affected by subsolidus processes. The Eu oxybarometer can analyze the cores of the earliest formed crystals in Martian meteorites, which means it can give us a better indication of the oxygen fugacity of the parent melt. The calibration of the Eu oxybarometer has been done with the basaltic shergottites before [4]. However, it has never been applied to nakhlites (Oe et al. [5] measured the depth of Eu anomaly in the synthetic pyroxene only at QFM). Partition coefficients are strongly affected by phase compositions, especially pyroxene Ca content and melt Al content [e.g., 5,6]. The composition of nakhlite pyroxene is rather different from basaltic shergottite pyroxene. Thus, there may be problems in applying the Eu oxybarometer calibration for the basaltic shergottites [7] to nakhlites. Thus, we report in this

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

    2016-04-05

    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.

  7. 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

  8. 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.

  9. Antiferromagnetism with divalent Eu in EuNi5As3

    NASA Astrophysics Data System (ADS)

    Jiang, W. B.; Smidman, M.; Xie, W.; Liu, J. Y.; Lee, J. M.; Chen, J. M.; Ho, S. C.; Ishii, H.; Tsuei, K. D.; Guo, C. Y.; Zhang, Y. J.; Lee, Hanoh; Yuan, H. Q.

    2017-01-01

    We have successfully synthesized single crystals of EuNi5As3 using a flux method, and we present a comprehensive study of the physical properties using magnetic susceptibility, specific heat, electrical resistivity, thermoelectric power, and x-ray absorption spectroscopy (XAS) measurements. EuNi5As3 undergoes two close antiferromagnetic transitions at respective temperatures of TN 1=7.2 K and TN 2=6.4 K, which are associated with the Eu2 + moments. Both transitions are suppressed upon applying a field, and we map the temperature-field phase diagrams for fields applied parallel and perpendicular to the easy a axis. XAS measurements reveal that the Eu is strongly divalent, with very little temperature dependence, indicating the localized Eu2 + nature of EuNi5As3 , with a lack of evidence for heavy-fermion behavior.

  10. Ferromagnetic behavior in mixed valence europium (Eu2+/Eu3+) oxide EuTi1-xMxO3 (M = Al3+ and Ga3+)

    NASA Astrophysics Data System (ADS)

    Akahoshi, Daisuke; Horie, Hiroki; Sakai, Shingo; Saito, Toshiaki

    2013-10-01

    We have investigated the Ti-site substitution effect on the magnetic properties of antiferromagnetic insulator EuTiO3 with a Néel temperature of ˜5 K. Partial substitution of Ti4+ with heterovalent Al3+ or Ga3+ turns the corresponding amount of magnetic Eu2+ into non-magnetic Eu3+. Both EuTi1-xAlxO3 (0.05 ≤ x ≤ 0.10) and EuTi1-xGaxO3 (0.05 ≤ x ≤ 0.10) exhibit ferromagnetic (FM) insulating behavior below ˜4 K. The Eu2+/Eu3+ mixed valence state probably contributes to the emergence of the FM behavior. Fine control of the magneto-electric (ME) phases of EuTi1-xAlxO3 and EuTi1-xGaxO3 would lead to intriguing ME phenomena such as giant ME effect.

  11. Anomalous Eu valence state and superconductivity in undoped Eu3Bi2S4F4.

    PubMed

    Zhai, Hui-Fei; Zhang, Pan; Wu, Si-Qi; He, Chao-Yang; Tang, Zhang-Tu; Jiang, Hao; Sun, Yun-Lei; Bao, Jin-Ke; Nowik, Israel; Felner, Israel; Zeng, Yue-Wu; Li, Yu-Ke; Xu, Xiao-Feng; Tao, Qian; Xu, Zhu-An; Cao, Guang-Han

    2014-10-29

    We have synthesized a novel europium bismuth sulfofluoride, Eu3Bi2S4F4, by solid-state reactions in sealed evacuated quartz ampules. The compound crystallizes in a tetragonal lattice (space group I4/mmm, a = 4.0771(1) Å, c = 32.4330(6) Å, and Z = 2), in which CaF2-type Eu3F4 layers and NaCl-like BiS2 bilayers stack alternately along the crystallographic c axis. There are two crystallographically distinct Eu sites, Eu(1) and Eu(2) at the Wyckoff positions 4e and 2a, respectively. Our bond valence sum calculation, based on the refined structural data, indicates that Eu(1) is essentially divalent, while Eu(2) has an average valence of ∼ +2.64(5). This anomalous Eu valence state is further confirmed and supported, respectively, by Mössbauer and magnetization measurements. The Eu(3+) components donate electrons into the conduction bands that are mainly composed of Bi 6px and 6py states. Consequently, the material itself shows metallic conduction and superconducts at 1.5 K without extrinsic chemical doping.

  12. U.S.-EU Cooperation Against Terrorism

    DTIC Science & Technology

    2010-07-09

    United States and the EU have pledged to enhance international information exchanges on lost and stolen passports and to promote travel document...Scanners,” Deutsche Welle, January 21, 2010. 10 “U.S. Conciliatory in Air Marshal Demands,” Associated Press, April 26, 2004; John M. Doyle, “U.S., EU To...and other interested states) to qualify. Among other measures, P.L. 110-53 called on VWP participants to meet certain security and passport

  13. U.S.-EU Cooperation Against Terrorism

    DTIC Science & Technology

    2014-12-01

    information systems.7 In addition, EU policy makers have been holding discussions with Internet and social media companies such as Google, Twitter...Hamas-related charities to its common terrorist list because some EU members view them as separate entities engaged in political or social work.24...viewed Hezbollah as providing needed social services in some of Lebanon’s poorest communities. On the other hand, critics of Hezbollah’s absence

  14. Eu(2+) luminescence in strontium aluminates.

    PubMed

    Dutczak, D; Jüstel, T; Ronda, C; Meijerink, A

    2015-06-21

    The luminescence properties of Eu(2+) doped strontium aluminates are reported and reviewed for a variety of aluminates, viz. SrAl12O19, SrAl4O7, Sr4Al14O25, SrAl2O4 and Sr3Al2O6. The aim of the research is to investigate the role of local coordination and covalency of the aluminate host lattice, related to the Sr/Al ratio, on the optical properties of the Eu(2+) ion. The UV and VUV excited luminescence spectra as well as luminescence decay curves were recorded to characterize the luminescence properties of the investigated aluminates. The emission of Eu(2+) ions varies over a wide spectral range, from ultraviolet (UV) to red, for the series of aluminates. The variation in emission color can be related to the crystal-field splitting of the 5d levels and the covalent interaction with the surrounding oxygen anions. In the least covalent material, viz. SrAl12O19:Eu(2+), narrow line emission due to the (6)P7/2-(8)S7/2 transition occurs at 4 K, indicating that the 4f(6)5d excited state is situated above the (6)P7/2(4f(7)) excited state around 360 nm. The most alkaline material, viz. Sr3Al2O6:Eu(2+) is the most covalent host and exhibits several d-f emission bands in the yellow to red spectral range due to the Eu(2+) ions located on different crystallographic Sr(2+) sites. The Eu(2+) emission spectra in the other aluminates confirm the trend that with increasing Sr/Al ratio the Eu(2+) emission shifts to longer wavelengths. Interesting differences are observed for the Eu(2+) from different crystallographic sites which cannot always be related with apparent differences in the first oxygen coordination sphere. The discussion gives insight into how in a similar class of materials, strontium aluminates, the emission color of Eu(2+) can be tuned over a wide spectral region.

  15. A reliable spatially normalized template of the human spinal cord--Applications to automated white matter/gray matter segmentation and tensor-based morphometry (TBM) mapping of gray matter alterations occurring with age.

    PubMed

    Taso, Manuel; Le Troter, Arnaud; Sdika, Michaël; Cohen-Adad, Julien; Arnoux, Pierre-Jean; Guye, Maxime; Ranjeva, Jean-Philippe; Callot, Virginie

    2015-08-15

    Recently, a T2*-weighted template and probabilistic atlas of the white and gray matter (WM, GM) of the spinal cord (SC) have been reported. Such template can be used as tissue-priors for automated WM/GM segmentation but can also provide a common reference and normalized space for group studies. Here, a new template has been created (AMU40), and accuracy of automatic template-based WM/GM segmentation was quantified. The feasibility of tensor-based morphometry (TBM) for studying voxel-wise morphological differences of SC between young and elderly healthy volunteers was also investigated. Sixty-five healthy subjects were divided into young (n=40, age<40years old, mean age 28±5years old) and elderly (n=25, age>50years old, mean age 57±5years old) groups and scanned at 3T using an axial high-resolution T2*-weighted sequence. Inhomogeneity correction and affine intensity normalization of the SC and cerebrospinal fluid (CSF) signal intensities across slices were performed prior to both construction of the AMU40 template and WM/GM template-based segmentation. The segmentation was achieved using non-linear spatial normalization of T2*-w MR images to the AMU40 template. Validation of WM/GM segmentations was performed with a leave-one-out procedure by calculating DICE similarity coefficients between manual and automated WM/GM masks. SC morphological differences between young and elderly healthy volunteers were assessed using the same non-linear spatial normalization of the subjects' MRI to a common template, derivation of the Jacobian determinant maps from the warping fields, and a TBM analysis. Results demonstrated robust WM/GM automated segmentation, with mean DICE values greater than 0.8. Concerning the TBM analysis, an anterior GM atrophy was highlighted in elderly volunteers, demonstrating thereby, for the first time, the feasibility of studying local structural alterations in the SC using tensor-based morphometry. This holds great promise for studies of morphological

  16. Quadrupole splitting and Eu partial lattice dynamics in europium orthophosphate EuPO 4

    NASA Astrophysics Data System (ADS)

    Klobes, B.; Arinicheva, Y.; Neumeier, S.; Simon, R. E.; Jafari, A.; Bosbach, D.; Hermann, R. P.

    2016-12-01

    Hyperfine interactions in europium orthophosphate EuPO4 were investigated using 151Eu Mössbauer spectroscopy from 6 to 300 K. The value of the quadrupole splitting and the asymmetry parameter were refined and further substantiated by nuclear forward scattering data obtained at room temperature. The temperature dependence of the relative absorption was modeled with an Eu specific Debye temperature of 221(1) K. Eu partial lattice dynamics were probed by means of nuclear inelastic scattering and the mean force constant, the Lamb-Mössbauer factor, the internal energy, the vibrational entropy, the average phonon group velocity were calculated using the extracted density of phonon states. In general, Eu specific vibrations are characterized by rather small phonon energies and contribute strongly to the total entropy of the system. Although there is no classical Debye like behavior at low vibrational energies, the average phonon group velocity can be reasonably approximated using a linear fit.

  17. Photoexcited Eu2+ spin dynamics in EuFe2As2

    NASA Astrophysics Data System (ADS)

    Pogrebna, A.; Mertelj, T.; Cao, G.; Xu, Z. A.; Mihailovic, D.

    2014-06-01

    Employing temperature dependent time-resolved optical femtosecond spectroscopy, we investigated the quasiparticle and Eu2+ spin relaxation dynamics in EuFe2As2 (EFA). As previously reported in other undoped iron-based pnictides, we observe the quasiparticle relaxation bottleneck due to the charge gap opening in the spin density wave (SDW) state below T SDW = 189 K. Below the Eu2+ antiferromagnetic (AFM) spin ordering temperature, T AFM = 19 K, we observe another slower relaxation component, which we attribute to the Eu2+ AFM order dynamics. The slow dynamics of this component suggests a weak coupling between the Eu2+ spins and the carriers in the Fe- d derived bands.

  18. 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.

  19. 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

  20. Do supranational EU institutions make a difference? EU asylum law before and after 'communitarization'.

    PubMed

    Ripoll Servent, Ariadna; Trauner, Florian

    2014-09-14

    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.

  1. The EU sustainable energy policy indicators framework.

    PubMed

    Streimikiene, Dalia; Sivickas, Gintautas

    2008-11-01

    The article deals with indicators framework to monitor implementation of the main EU (European Union) directives and other policy documents targeting sustainable energy development. The main EU directives which have impact on sustainable energy development are directives promoting energy efficiency and use of renewable energy sources, directives implementing greenhouse gas mitigation and atmospheric pollution reduction policies and other policy documents and strategies targeting energy sector. Promotion of use of renewable energy sources and energy efficiency improvements are among priorities of EU energy policy because the use of renewable energy sources and energy efficiency improvements has positive impact on energy security and climate change mitigation. The framework of indicators can be developed to establish the main targets set by EU energy and environmental policies allowing to connect indicators via chain of mutual impacts and to define policies and measures necessary to achieve established targets based on assessment of their impact on the targeted indicators representing sustainable energy development aims. The article discusses the application of indicators framework for EU sustainable energy policy analysis and presents the case study of this policy tool application for Baltic States. The article also discusses the use of biomass in Baltic States and future considerations in this field.

  2. Horizon 2020 EuPRAXIA design study

    NASA Astrophysics Data System (ADS)

    Walker, P. A.; Alesini, P. D.; Alexandrova, A. S.; Anania, M. P.; E Andreev, N.; Andriyash, I.; Aschikhin, A.; Assmann, R. W.; Audet, T.; Bacci, A.; Barna, I. F.; Beaton, A.; Beck, A.; Beluze, A.; Bernhard, A.; Bielawski, S.; Bisesto, F. G.; Boedewadt, J.; Brandi, F.; Bringer, O.; Brinkmann, R.; Bründermann, E.; Büscher, M.; Bussmann, M.; Bussolino, G. C.; Chance, A.; Chanteloup, J. C.; Chen, M.; Chiadroni, E.; Cianchi, A.; Clarke, J.; Cole, J.; E Couprie, M.; Croia, M.; Cros, B.; Dale, J.; Dattoli, G.; Delerue, N.; Delferriere, O.; Delinikolas, P.; Dias, J.; Dorda, U.; Ertel, K.; Ferran Pousa, A.; Ferrario, M.; Filippi, F.; Fils, J.; Fiorito, R.; Fonseca, R. A.; Galimberti, M.; Gallo, A.; Garzella, D.; Gastinel, P.; Giove, D.; Giribono, A.; Gizzi, L. A.; Grüner, F. J.; Habib, A. F.; Haefner, L. C.; Heinemann, T.; Hidding, B.; Holzer, B. J.; Hooker, S. M.; Hosokai, T.; Irman, A.; Jaroszynski, D. A.; Jaster-Merz, S.; Joshi, C.; Kaluza, M. C.; Kando, M.; Karger, O. S.; Karsch, S.; Khazanov, E.; Khikhlukha, D.; Knetsch, A.; Kocon, D.; Koester, P.; Kononenko, O.; Korn, G.; Kostyukov, I.; Labate, L.; Lechner, C.; Leemans, W. P.; Lehrach, A.; Y Li, F.; Li, X.; Libov, V.; Lifschitz, A.; Litvinenko, V.; Lu, W.; Maier, A. R.; Malka, V.; Manahan, G. G.; Mangles, S. P. D.; Marchetti, B.; Marocchino, A.; Martinez de la Ossa, A.; Martins, J. L.; Massimo, F.; Mathieu, F.; Maynard, G.; Mehrling, T. J.; Y Molodozhentsev, A.; Mosnier, A.; Mostacci, A.; Mueller, A. S.; Najmudin, Z.; Nghiem, P. A. P.; Nguyen, F.; Niknejadi, P.; Osterhoff, J.; Papadopoulos, D.; Patrizi, B.; Pattathil, R.; Petrillo, V.; Pocsai, M. A.; Poder, K.; Pompili, R.; Pribyl, L.; Pugacheva, D.; Romeo, S.; Rossi, A. R.; Roussel, E.; Sahai, A. A.; Scherkl, P.; Schramm, U.; Schroeder, C. B.; Schwindling, J.; Scifo, J.; Serafini, L.; Sheng, Z. M.; Silva, L. O.; Silva, T.; Simon, C.; Sinha, U.; Specka, A.; Streeter, M. J. V.; Svystun, E. N.; Symes, D.; Szwaj, C.; Tauscher, G.; Thomas, A. G. R.; Thompson, N.; Toci, G.; Tomassini, P.; Vaccarezza, C.; Vannini, M.; Vieira, J. M.; Villa, F.; Wahlström, C.-G.; Walczak, R.; Weikum, M. K.; Welsch, C. P.; Wiemann, C.; Wolfenden, J.; Xia, G.; Yabashi, M.; Yu, L.; Zhu, J.; Zigler, A.

    2017-07-01

    The Horizon 2020 Project EuPRAXIA (“European Plasma Research Accelerator with eXcellence In Applications”) is preparing a conceptual design report of a highly compact and cost-effective European facility with multi-GeV electron beams using plasma as the acceleration medium. The accelerator facility will be based on a laser and/or a beam driven plasma acceleration approach and will be used for photon science, high-energy physics (HEP) detector tests, and other applications such as compact X-ray sources for medical imaging or material processing. EuPRAXIA started in November 2015 and will deliver the design report in October 2019. EuPRAXIA aims to be included on the ESFRI roadmap in 2020.

  3. Effect of Eu/Sr Ratios on Ferroelectric and Fluorescent Properties of Eu-Substituted Strontium Bismuth Tantalate Films

    NASA Astrophysics Data System (ADS)

    Aizawa, Koji; Ohtani, Yusuke

    2008-09-01

    The ferroelectric and fluorescent properties of Eu-substituted strontium bismuth tantalate (Eu-SBT) films grown on Pt/Ti/SiO2/Si substrates by spin coating were investigated. The polycrystalline Eu-SBT films with Aurivillius phases were grown at Eu/Sr ratios between 0 and 0.25. Moreover, the lattice constants along the a- and c-axes at Eu/Sr=0.25 in comparison with Eu/Sr=0 decreased by approximately 0.36 and 0.19%, respectively. The remnant polarization values of the Eu-SBT films with Eu/Sr ratios of 0 and 0.25 were approximately 6.6 and 5.8 µC/cm2, respectively. The 80%-fatigue endurance of a Eu-SBT film with Eu/Sr=0.25 was approximately 3.1×109 cycles when a 10 kHz triangular wave with an amplitude of 8 V (approximately 530 kV/cm electric field) was used. The photoluminescence intensity of the Eu-SBT films was increased by Eu doping with negligible change of the remnant polarization. Emission peaks at approximately 600 nm in wavelength, which were associated with the 5D0-7F transitions of Eu3+, were observed in the Eu-SBT films.

  4. Synthesis, structure, and magnetic properties of the fullerene-based ferromagnets Eu3C70 and Eu9C70.

    PubMed

    Takenobu, Taishi; Chi, Dam H; Margadonna, Serena; Prassides, Kosmas; Kubozono, Yoshihiro; Fitch, Andrew N; Kato, Ken-Ichi; Iwasa, Yoshihiro

    2003-02-19

    Intercalation of C(70) with europium affords two kinds of magnetic compounds, a canted antiferromagnet Eu(x)C(70) (x approximately 3) and a ferromagnet Eu(x)C(70) (x approximately 9) with transition temperatures (T(C)) of 5 and 38 K, respectively. The Curie constants in the paramagnetic phase and the saturation moment in the ferromagnetic phase are both understood by the full moment of Eu(2+) for both systems. The structure of Eu(3)(-)(delta)C(70) (delta approximately 0.27) is pseudo-monoclinic, derived by a simple deformation of the parent face-centered cubic (fcc) structure. Eu(9)(-)(delta)C(70) (delta approximately 0.2) forms an fcc structure, in which cuboctahedral clustering of Eu(2+) ions is observed in the enhanced size octahedral holes. The observed T(C) of the Eu(9)(-)(delta)C(70) ferromagnet is comparable to or larger than those of simple binary Eu-based ferromagnets, such as Eu chalcogenides or carbides, despite the low atomic ratio of Eu in the chemical formulas. This can be understood by the short Eu(2+)-Eu(2+) distances and high coordination numbers permitted by the multiple occupation by Eu(2+) ions of the expanded octahedral interstitial sites in higher fullerene-based solids.

  5. [Experimental study on the Eu isotopic enrichment].

    PubMed

    Huang, Xue-ren; Zhong, Da; Mei, Gang-hua; Zhu, Xi-wen

    2002-10-01

    The polarized atomic beam has found many applications, such as in studying atomic scattering processes, producing polarized nucleus, verifying the parity principle, measuring surface parameters and enriching isotopes. In this paper, we mainly described the experiment of Eu isotope enrichment by means of magnetic deflection. According to the special inner energy level structure of Eu atom, we analyzed the theory of the polarized atomic beam and described the main experimental set-up. Using one coherent laser with the wavelength of 601.9 nm and sigma polarization, Eu153 atoms have been selectively optical pumped and polarized, so positive and negative polarized atomic beams could be produced. The polarized atomic beams have been focused and defocused after passing through the deflection by hex-magnet. Finally, some clear enrichmental signal has been obtained in way of hot-wire detection. During the process of the experiment, we carefully selected the optimized conditions, the Eu153 enrichment effect of 4% can be achieved using only one coherent laser.

  6. 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…

  7. 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…

  8. Eu(2+) and Eu(3+) co-activated LaAlO3 phosphor: synthesis and tuned luminescence.

    PubMed

    Chen, Wanping

    2015-10-28

    Sr(2+) and Si(4+) ion doped LaAlO3:Eu phosphors were synthesized through a high-temperature solid-state reaction route. Their phase component and photoluminescence properties were investigated. Under ultraviolet (UV) light excitation, the phosphors show simultaneously blue emission of the Eu(2+) ion and orange-red emission of the Eu(3+) ion. The relative emission intensity of both Eu(2+) and Eu(3+) ions can be tuned by changing the doping concentration of the Sr(2+), Si(4+) and Eu(3+) ions. In contrast to the Sr(2+) ion, the incorporation of Si(4+) ion can effectively enhance the emission of Eu(2+). The optimal doping concentration of the Eu(3+) and Si(4+) ions are about 0.02 and 0.03, respectively. The results indicate that the phosphor may be a potential candidate for white LED lighting applications.

  9. EuCliD--a medical registry.

    PubMed

    Steil, H; Amato, C; Carioni, C; Kirchgessner, J; Marcelli, D; Mitteregger, A; Moscardo, V; Orlandini, G; Gatti, E

    2004-01-01

    The European Clinical Database EuCliD small star, filled has been developed as a tool for supervising selected quality indicators of about 200 European dialysis centers. Major efforts had to be made to comply with local and European laws regarding data security. EuCliD is a Lotus Notes based flat-file database currently containing medical data of more than 14,000 dialysis patients from 10 European countries. Another 15,000 patients from 150 centers in 4 South-American countries will be added soon. Data are entered either manually or by means of interfaces to existing local data managing systems. This information is transferred to a central Lotus Notes Server. Data evaluation was performed with statistical tools like SPSS. EuCliD is used as a part of the CQI (Continuous Quality Improvement) management system of Fresenius Medical Care (FMC) dialysis units. Each participating dialysis center receives (currently every half year) benchmarking reports at a regular interval. The benchmark for all quality parameters is the weighted mean of the corresponding data of all centers. An obvious impact of data sampling and data evaluation on the quality of the treatments could be observed within the first one and a half years of working with EuCliD. This also concerns important outcome predictors like Kt/V and hemoglobin concentration as the outcome itself expressed in hospitalization days and survival rates. With the help of EuCliD the user is able to sample clinical data, identify problems, search for solutions with the aim of improving the dialysis treatment quality and guarantee a high-class treatment quality for all patients.

  10. Synthesis and Characterization of Eu-Doped Cadmium Selenide Nanocrystals

    SciTech Connect

    Raola, O. E.

    2002-01-01

    Substitution of Cd(II) sites by Eu ions in 5.0 nm {+-} 0.25 nm CdSe, Cd{sub 1-x}Eu{sub x}Se (x=0.374), can be achieved by modification of a lyothermal, single source precursor method. The Eu guest ion occupies a tetrahedral lattice site as a Eu(III) defect ion based on analysis of the XPS and XAS data. XRD and XAS measurements show a linear contraction of the lattice parameters for increasing Eu(III) concentration consistent with statistical substitution at both core and surface sites in the lattice by a random ion displacement mechanism. On the basis of a Vegard's law analysis, the Eu(III) ion is substituted in the tetrahedral cationic lattice site without formation of vacancies or phase segregation of the Eu ion in the lattice.

  11. Saturation Behavior of Eu ion emission in GaN

    NASA Astrophysics Data System (ADS)

    Hernandez, Natalie; Mitchell, Brandon; Fujiwara, Yasufumi; Dierolf, Volkmar

    Europium doped Gallium Nitride (GaN:Eu) has been recognized as a candidate for the red-emitting active layer in nitride-based light emitting diodes. To better comprehend the excitation energy transfer from the excited GaN host to the Eu ion, we performed an extensive analysis of GaN:Eu and GaN co-doped with Eu and other dopants (Silicon and Magnesium). We determined how various growth parameters manipulated site formations and measured the optical accessibility of the Eu ions within the GaN host and the excitation efficiency of the energy transfer between the host material and the Eu ions. Furthermore, we derived a model for the saturation behavior of the emission of Eu ions within GaN. Our results suggest that the saturation behavior is strongly influenced by different crystal growth specifications and co-dopants.

  12. Determining Factors for EU Military Intervention

    DTIC Science & Technology

    2013-05-23

    Lakes region was in response to the 1994 Rwanda tribal genocide and subsequent violence that spilled over the Zaire border.27 The first phase of...ITEM- 013+DOC+XML+V0//EN (accessed February 15, 2013). 27The war that ensued from the 1994 Rwanda genocide is commonly known as the First Congo War...defense policy. While the Balkans genocide triggered consensus, the road to actually developing a EU security policy would prove long and frustrating

  13. 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.

  14. 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.

  15. Effect of Electrode and EuO Thickness on EuO-Electrode Interface in Tunneling Spin Filter

    SciTech Connect

    Negusse,E.; Holroyd, J.; Liberati, M.; Dvorak, J.; Idzerda, Y.; Santos, T.; Moodera, J.; Arenholz, E.

    2006-01-01

    The effect of electrode material and EuO film thickness on the interface between the two was studied. Of the electrodes examined, yttrium was found to decrease the formation of the nonmagnetic oxide Eu{sub 2}O{sub 3}. By decomposing the x-ray absorption spectroscopy (XAS) spectra of the samples with different electrodes against the reference EuO and Eu{sub 2}O{sub 3} spectra, the relative fraction of these two species was quantified. Multilayers with silver electrodes had the highest amount of Eu{sub 2}O{sub 3}, about 41%, whereas aluminum had 28% compared to the less than 5% observed for the multilayers with yttrium electrodes. A slight decrease in the fraction of Eu{sub 2}O{sub 3} with increasing EuO thickness was found. Angle dependent XAS measurements, done on 80 A{sup o} EuO film, indicated the presence of Eu{sub 2}O{sub 3} at high grazing angles which then decreased drastically with decreasing grazing angle. This indicated that the Eu{sub 2}O{sub 3} was localized at the EuO-electrode interface.

  16. 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.

  17. 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.

  18. Europium gallium garnet (Eu3Ga5O12) and Eu3GaO6: Synthesis and material properties

    NASA Astrophysics Data System (ADS)

    Sawada, Kenji; Nakamura, Toshihiro; Adachi, Sadao

    2016-10-01

    Eu-Ga-O ternary compounds were synthesized from a mixture of cubic (c-) Eu2O3 and monoclinic Ga2O3 (β-Ga2O3) raw powders using the solid-state reaction method by calcination at Tc = 1200 °C. The structural and optical properties of the Eu-Ga-O ternary compounds were investigated using X-ray diffraction analysis, photoluminescence (PL) analysis, PL excitation (PLE) spectroscopy, and Raman scattering measurements. Stoichiometric compounds such as cubic Eu3Ga5O12 (EGG) and orthorhombic Eu3GaO6 were synthesized using molar ratios of x = 0.375 and 0.75 [x≡Eu2O3/(Eu2O3 + Ga2O3)], respectively, together with the end-point binary compounds β-Ga2O3 (x = 0) and monoclinic (m-) Eu2O3 (x = 1.0). The structural change from "cubic" to "monoclinic" in Eu2O3 is due to the structural phase transition occurring at Tc ≥ 1050 °C. In principle, the perovskite-type EuGaO3 and monoclinic Eu4Ga2O9 can also be synthesized at x = 0.5 and 0.667, respectively; however, such stoichiometric compounds could not be synthesized in this study. The PL and PLE properties of EGG and Eu3GaO6 were studied in detail. The temperature dependence of the PL spectra was observed through measurements carried out between T = 20 and 300 K and explained using a newly developed model. Raman scattering measurements were also performed on the Eu-Ga-O ternary systems over the entire composition range from x = 0 (β-Ga2O3) to 1.0 (m-Eu2O3).

  19. 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

  20. Temperature dependence of Eu-related EPR spectra in CsBr:Eu needle image plates

    SciTech Connect

    Loncke, F.; Vrielinck, H.; Matthys, P.; Callens, F.; Tahon, J.-P.; Leblans, P.; Ahmad, I.; Goovaerts, E.

    2009-05-01

    Vacuum-deposited CsBr needle plates doped with Eu{sup 2+} have been investigated with Q ({approx}34 GHz) and W ({approx}95 GHz) band electron paramagnetic resonance in a large temperature interval (4 K: room temperature). At low temperatures (<35 K), two Eu-related centers were found with different symmetry (tetragonal and orthorhombic), while in earlier studies at room temperature only one center was found with tetragonal symmetry. Possible models for the three defects are investigated, taking into account their temperature behavior, their symmetry, and the atypical values of their zero-field splitting parameters.

  1. Coexistence phenomenon of Ce(3+)-Ce(4+) and Eu(2+)-Eu(3+) in Ce/Eu co-doped LiBaB9O15 phosphor: luminescence and energy transfer.

    PubMed

    Li, Ting; Li, Panlai; Wang, Zhijun; Xu, Shuchao; Bai, Qiongyu; Yang, Zhiping

    2017-02-01

    Ce/Eu-doped LiBaB9O15 (LBB) samples were prepared via conventional high temperature solid state reactions. The XRD patterns, crystal structures, luminescence properties, and decay times were investigated systematically. Ce(3+) ions exist in LBB:xCe(3+) that were synthesized in a reducing atmosphere and in an air atmosphere. However, we observed Eu(2+) ions in LBB:yEu(2+) in a reducing atmosphere and Eu(3+) ions in LBB:zEu(3+) in an air atmosphere. LBB:0.05Ce(3+),yEu(2+) phosphors synthesized in a reducing atmosphere only possess Ce(3+) and Eu(2+) and exhibit a broad excitation band ranging from 350 to 425 nm. A reduction phenomenon of Eu(3+) → Eu(2+) and coexistence of Ce(4+), Ce(3+), Eu(2+) and Eu(3+) were observed when LBB:0.05Ce,wEu phosphors were synthesized in an air atmosphere. There are three processes in LBB:0.05Ce,wEu, i.e., energy transfers from Ce(3+) to Eu(2+) and from Eu(2+) to Eu(3+), and metal-metal charge transfer (MMCT) between Ce(3+) and Eu(3+). Moreover, the MMCT process is dominant in LBB:0.05Ce,wEu due to less efficient energy transfer from Ce(3+) to Eu(2+). Moreover, the CIE coordinates of LBB:0.05Ce,wEu vary systematically from light blue (0.313, 0.129) to red (0.589, 0.315) for LBB:0.05Ce(3+),wEu synthesized in air with the changes in Eu ion concentration. Thus, we can control the color by controlling the synthesis atmospheres.

  2. 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.

  3. Evidence of Eu2+ 4f electrons in the valence band spectra of EuTiO3 and EuZrO3

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    We report on optical band gap and valence electronic structure of two Eu2+-based perovskites, EuTiO3 and EuZrO3 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 4f7 electron band. The O 2p band shows the features similar to those of the Ba(Sr)TiO3 perovskites except that it is shifted to higher binding energies. Appearance of the Eu2+ 4f7 band is a reason for narrowing of the optical band gap in the title compounds as compared to their Sr-based analogues.

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

    DOE PAGES

    Horoz, Sabit; Yakami, Baichhabi; Poudyal, Uma; ...

    2016-04-27

    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 incidentmore » 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.« less

  5. Large magnetocaloric effect in sintered ferromagnetic EuS

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koichi; Li, Liang; Hirai, Shinji; Nakamura, Eiji; Murayama, Daiki; Ura, Yutaro; Abe, Satoshi

    2016-10-01

    We present magnetocaloric effect measurements of the ferromagnetic semiconductor EuS in the vicinity of its ordering temperature. Single phase EuS powder was synthesized by CS2 gas sulfurization of Eu2O3. A sintered compact with relative density over 95% was prepared by pulsed electric current sintering of the powder. Temperature and magnetic field dependence of the magnetization and specific heat were characteristic of a paramagnetic to ferromagnetic second order phase transition. The entropy change induced by an external magnetic field and the specific heat were both close to those of a single crystal. We obtained an entropy-temperature (S-T) diagram of the EuS sintered compact. Carnot cycle liquefaction of hydrogen using EuS was compared with several other materials, with results indicating that sintered EuS is an excellent magnetic refrigerant for hydrogen liquefaction.

  6. Eu oxidation state in fluorozirconate-based glass ceramics

    PubMed Central

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

    2009-01-01

    The influence of InF3 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 InF3 to the melt decreases the Eu2+∕Eu3+ mole ratio, while remelting leads to a significant change in the Eu2+∕Eu3+ ratio in favor of Eu2+. Photoluminescence spectroscopy shows that additional annealing steps lead to the formation of BaCl2 nanoparticles in the glass. In as-made glass ceramics containing InF3, 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. PMID:20057931

  7. Eu oxidation state in fluorozirconate-based glass ceramics

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    The influence of InF3 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 InF3 to the melt decreases the Eu2+/Eu3+ mole ratio, while remelting leads to a significant change in the Eu2+/Eu3+ ratio in favor of Eu2+. Photoluminescence spectroscopy shows that additional annealing steps lead to the formation of BaCl2 nanoparticles in the glass. In as-made glass ceramics containing InF3, 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.

  8. 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.

  9. Quasiparticle bandstructure of antiferromagnetic EuTe

    NASA Astrophysics Data System (ADS)

    Mathi Jaya, S.; Nolting, W.

    1997-11-01

    The temperature-dependent electronic quasiparticle spectrum of the antiferromagnetic semiconductor EuTe is derived by use of a combination of a many-body model procedure with a tight-binding - `linear muffin tin orbital' (TB - LMTO) band structure calculation. The central part is the d - f model for a single band electron (`test electron') being exchange coupled to the antiferromagnetically ordered localized moments of the Eu ions. The single-electron Bloch energies of the d - f model are taken from a TB - LMTO calculation for paramagnetic EuTe. The d - f model is evaluated by a recently proposed moment conserving Green function technique to get the temperature-dependent sublattice - quasiparticle bandstructure (S - QBS) and sublattice - quasiparticle density of states (S - QDOS) of the unoccupied 5d - 6s energy bands. Unconventional correlation effects and the appearance of characteristic quasiparticles (`magnetic polarons') are worked out in detail. The temperature dependence of the S - QDOS and S - QBS is mainly provoked by the spectral weights of the energy dispersions. Minority- and majority-spin spectra coincide for all temperatures but with different densities of states. Upon cooling from 0953-8984/9/47/012/img1 to T = 0 K the lower conduction band edge exhibits a small blue shift of -0.025 eV in accordance with the experiment. Quasiparticle damping manifesting itself in a temperature-dependent broadening of the spectral density peaks arises from spin exchange processes between (5d - 6s) conduction band electrons and localized 4f moments.

  10. 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

  11. 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.

  12. Mobility of health professionals pre and post 2004 and 2007 EU enlargements: evidence from the EU project PROMeTHEUS.

    PubMed

    Ognyanova, Diana; Maier, Claudia B; Wismar, Matthias; Girasek, Edmond; Busse, Reinhard

    2012-12-01

    EU enlargement has facilitated the mobility of EU citizens, including health professionals, from the 2004 and 2007 EU accession states. Fears have been raised about a mass exodus of health professionals and the consequences for the operation of health systems. However, to date a systematic analysis of the EU enlargement's effects on the mobility of health professionals has been lacking. The aim of this article is to shed light on the changes in the scale of movement, trends and directions of flows pre and post 2004 and 2007 EU enlargements. The study follows a pan-European secondary data analysis to (i) quantitatively and (ii) qualitatively analyse mobility before and after the EU enlargement. (i) The secondary data analysis covers 34 countries (including all EU Member States). (ii) Data were triangulated with the findings of 17 country case studies to qualitatively assess the effects of enlargement on health workforce mobility. The stock of health professionals from the new (EU-12) into the old EU Member States (EU-15) have increased following EU accession. The stock of medical doctors from the EU-12 in the EU-15 countries has more than doubled between 2003 and 2007. The available data suggest the same trend for dentists. The extremely limited data for nurses show that the stock of nurses has, in contrast, only slightly increased. However, while no reliable data is available evidence suggests that the number of undocumented or self-employed migrant nurses in the home-care sector has significantly increased. Health professionals trained in the EU-12 are becoming increasingly important in providing sufficient health care in some destination countries and regions facing staff shortages. A mass exodus of health professionals has not taken place after the 2004 and 2007 EU enlargements. The estimated annual outflows from the EU-12 countries have rarely exceeded 3% of the domestic workforce. This is partly due to labour market restrictions in the destination countries

  13. The magnetic structure of EuCu2Sb2

    DOE PAGES

    Ryan, D. H.; Cadogan, J. M.; Anand, V. K.; ...

    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

  14. Adsorption of Eu(III) onto roots of water hyacinth

    SciTech Connect

    Kelley, C.; Mielke, R.E.; Dimaquibo, D.; Curtis, A.J.; Dewitt, J.G.

    1999-05-01

    The water hyacinth (Eichhornia crassipes) has drawn attention as a plant capable of removing pollutants, including toxic metals, from water. The authors are interested in the capacity of the water hyacinth to remediate aquatic environments that have been contaminated with the lanthanide metal, europium Eu(III). Using scanning electron microscopy (SEM) they have been able to determine that Eu(III) is adsorbed onto the surface of the roots from water and that the highest concentration of Eu(III) is on the root hairs. X-ray absorption spectroscopy (XAS) techniques were used to speciate the Eu(III) adsorbed onto the surface of the roots. The XAS data for Eu-contaminated water hyacinth roots provides evidence of a Eu-oxygen environment and establishes that Eu(III) is coordinated to 10--11 oxygen atoms at a distance of 2.44 {angstrom}. This likely involves binding of Eu(III) to the root via carboxylate groups and hydration of Eu(III) at the root surface.

  15. Effect of Eu3+ concentration on photoluminescence and thermoluminescence behavior of YBO3:Eu3+ phosphor

    NASA Astrophysics Data System (ADS)

    Dubey, Vikas; Kaur, Jagjeet; Agrawal, Sadhana; Suryanarayana, N. S.; Murthy, K. V. R.

    2014-03-01

    The present paper reports the synthesis, photoluminescence (PL) and thermoluminescence (TL) studies of Eu3+ doped YBO3 phosphor. The samples were prepared by the conventional solid state reaction method with different concentrations of Eu3+ ions, which is the most suitable method for large-scale production. The prepared phosphor sample was characterized using X-ray diffraction (XRD), Field Emission Gun Scanning Electron Microscopy (FEGSEM), high resolution transmission electron microscopy (HRTEM), Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence (PL), thermoluminescence (TL) and CIE coordinate techniques. The PL emission was observed in the range 575-650 nm range for the YBO3 phosphor doped with Eu3+. Excitation spectrum found at 237, 254 and 395 nm. Sharp peaks found around 594, 612 and 628 nm with high intensity. From the XRD data, using the Scherer's formula the calculated average crystallite size of Eu3+ doped YBO3 phosphor is around 201 nm. Thermoluminescence study was carried out for the phosphor with UV, beta and gamma irradiation. The present phosphor can act as single host for red-orange light emission in display devices.

  16. 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.

  17. Transport and Magnetic Properties of EuAl4 and EuGa4

    NASA Astrophysics Data System (ADS)

    Nakamura, Ai; Uejo, Taro; Honda, Fuminori; Takeuchi, Tetsuya; Harima, Hisatomo; Yamamoto, Etsuji; Haga, Yoshinori; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

    2015-12-01

    We succeeded in growing a single crystal of the Eu-divalent compound EuAl4 with the BaAl4-type tetragonal structure by the Al self-flux method and measured the electrical resistivity, magnetic susceptibility, magnetization, specific heat, and thermoelectric power. EuAl4 orders antiferromagnetically below TN1 = 15.4 K, with three successive antiferromagnetic transitions at TN2 = 13.2 K, TN3 = 12.2 K, and TN4 = 10.0 K. The latter two transitions are of the first-order. The corresponding magnetization curve indicates three successive metamagnetic transitions with hystereses and saturates above 16 kOe. We observed a plausible characteristic feature of the charge density wave (CDW) below TCDW = 140 K. We also studied an effect of pressure on the electronic state by measuring the electrical resistivity and thermoelectric power. TCDW is found to decrease with increasing pressure at a rate of dTCDW/dP = -54.7 K/GPa and becomes zero at about 2.5 GPa. The present antiferromagnetic ordering is, however, found to be stable at higher pressures up to 7 GPa in EuAl4. On the other hand, the different characteristic CDW was observed in EuGa4, not at ambient pressure but above 1 GPa, and TCDW increases with increasing pressure. Above 6 GPa, we found that the antiferromagnetic ordering is changed into another first-order-like phase transition. Its characteristic feature is similar to that of the valence transition, and the heavy fermion state is realized at low temperatures.

  18. Luminescence properties of dual valence Eu doped nano-crystalline BaF2 embedded glass-ceramics and observation of Eu2+ → Eu3+ energy transfer.

    PubMed

    Biswas, Kaushik; Sontakke, Atul D; Sen, R; Annapurna, K

    2012-03-01

    Europium doped glass-ceramics containing BaF(2) nano-crystals have been prepared by using the controlled crystallization of melt-quenched glasses. X-ray diffraction and transmission electron microscopy have confirmed the presence of cubic BaF(2) nano-crystalline phase in glass matrix in the ceramized samples. Incorporation of rare earth ions into the formed crystalline phase having low phonon energy of 346 cm(-1) has been demonstrated from the emission spectra of Eu(3+) ions showing the transitions from upper excitation states (5)D(J) (J = 1, 2, and 3) to ground states for the glass-ceramics samples. The presence of divalent europium ions in glass and glass-ceramics samples is confirmed from the dominant blue emission corresponding to its 5d-4f transition under an excitation of 300 nm. Increase in the reduction of trivalent europium (Eu(3+)) ions to divalent (Eu(2+)) with the extent of ceramization is explained by charge compensation model based on substitution defect mechanisms. Further, the phenomenon of energy transfer from Eu(2+) to Eu(3+) ion by radiative trapping or re-absorption is evidenced which increases with the degree of ceramization. For the first time, the reduction of Eu(3+) to Eu(2+) under normal air atmospheric condition has been observed in a BaF(2) containing oxyfluoride glass-ceramics system.

  19. 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.

  20. Better understanding of the EU regulatory frameworks for cosmetic products.

    PubMed

    Rasmussen, Kirsten; Mech, Agnieszka

    2014-05-01

    This letter to the editor corrects some misunderstandings regarding the EU regulations covering cosmetic products stated in a recent publication by A. Sobek et al. "In the shadow of the cosmetics directive - Inconsistencies in EU environmental hazard classification requirements for UV-filters" published in Science of the Total Environment 461-462 (2013) 706-711.

  1. EU nurse figures in decline long before Brexit vote.

    PubMed

    Mckew, Matthew

    2017-03-08

    The falling number of European Union (EU) nurses applying to work in the UK has been widely blamed on Brexit. But figures obtained by Nursing Standard reveal interest from EU nurses was waning months before the June 2016 referendum, a trend experts say could be due to tougher language requirements introduced by the Nursing and Midwifery Council (NMC).

  2. EU-US ABWG AgENCODE Workshop

    USDA-ARS?s Scientific Manuscript database

    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...

  3. 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…

  4. 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…

  5. X-ray absorption and emission spectroscopy study of Mn and Co valence and spin states in TbM n1 -xC oxO3

    NASA Astrophysics Data System (ADS)

    Cuartero, V.; Lafuerza, S.; Rovezzi, M.; García, J.; Blasco, J.; Subías, G.; Jiménez, E.

    2016-10-01

    The valence and spin state evolution of Mn and Co on TbM n1 -xC oxO3 series is precisely determined by means of soft and hard x-ray absorption spectroscopy (XAS) and K β x-ray emission spectroscopy (XES). Our results show the change from M n3 + to M n4 + both high-spin (HS) together with the evolution from C o2 + HS to C o3 + low-spin (LS) with increasing x . In addition, high energy resolution XAS spectra on the K pre-edge region are interpreted in terms of the strong charge transfer and hybridization effects along the series. These results correlate well with the spin values of Mn and Co atoms obtained from the K β XES data. In this paper, we determine that Co enters into the transition metal sublattice of TbMn O3 as a divalent ion in HS state, destabilizing the Mn long-range magnetic order since very low doping compositions (x ≤0.1 ). Samples in the intermediate composition range (0.4 ≤x ≤0.6 ) adopt the crystal structure of a double perovskite with long-range ferromagnetic ordering which is due to M n4 + -O-C o2 + superexchange interactions with both cations in HS configuration. Ferromagnetism vanishes for x ≥0.7 due to the structural disorder that collapses the double perovskite structure. The spectroscopic techniques reveal the occurrence of M n4 + HS and a fluctuating valence state C o2 + HS/C o3 + LS in this composition range. Disorder and competitive interactions lead to a magnetic glassy behavior in these samples.

  6. Valences of dopants in Eu2+ persistent luminescence materials

    NASA Astrophysics Data System (ADS)

    Lastusaari, M.; Brito, H. F.; Carlson, S.; Hölsä, J.; Laamanen, T.; Rodrigues, L. C. V.; Welter, E.

    2014-04-01

    The existence and effect of different rare earth (R2+/3+/IV) ions in SrAl2O4:Eu2+,R3+ and M2MgSi2O7:Eu2+,R3+ (M: Sr, Ba) persistent luminescence materials was studied with XANES (x-ray absorption near edge structure) measurements at HASYLAB/DESY (Hamburg, Germany) and MAX-lab (Lund, Sweden). The experiments were carried out at 298 K for selected rare earth (co-)dopants (Eu2+; Ce3+, Nd3+, Sm3+, Dy3+ and Yb3+). The co-existence of Eu2+ and Eu3+ was observed in all materials. The co-dopants were always in the trivalent form.

  7. [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.

  8. Magnetic anomalies in EuO/nonmagnetic insulator multilayered films

    SciTech Connect

    Sohma, M.; Kawaguchi, K.; Oosawa, Y.

    1997-04-01

    Ferromagnetic EuO multilayered films (MLs) were fabricated with nonmagnetic oxides such as MgO, ZrO{sub 2}, and Y{sub 2}O{sub 3}. The EuO MLs showed increased Curie temperature (T{sub c}) and metal insulator transition temperature (T{sub mi}) than the bulk values due to oxygen deficiency. However, {sup 151}Eu M{umlt o}ssbauer spectra did not exhibit such an anomaly in T{sub c}. It suggests a field induced magnetic component in the MLs. Significant increase of coercive force (H{sub c}) with decreasing EuO layer thickness was observed only in EuO/MgO MLs. It was suggested that this increase was originated from a kind of interface effect. {copyright} {ital 1997 American Institute of Physics.}

  9. Preparation and luminescence characteristics of Eu2+ activated silicate phosphor

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    This paper synthesizes the Sr2SiO4 : Eu2+ phosphor by high temperature solid-state reaction. The emission spectrum of Sr2SiO4 : Eu2+ shows two bands centred at 480 and 547 nm, which agree well with the calculation values of emission spectrum, and the location of yellow emission of Sr2SiO4 : Eu2+ is influenced by the Eu2+ concentration. The excitation spectrum for 547nm emission has two bands at 363 and 402 nm. The emission spectrum of white light emitting diodes (w-LEDs) based on Sr2SiO4 :Eu2+ phosphor + InGaN LED was investigated.

  10. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    The anion photoelectron (PE) spectra of EuH- and the PE spectrum of overlapping EuOH- and EuO- 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 8Σ- anion ground states arising from the 4f7σ6s2 superconfiguration to the close-lying neutral 9Σ- and 7Σ- states arising from the 4f7σ6s superconfiguration are observed spaced by an energy interval similar to the free Eu+ [4f76s] 9S - 7S 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- photodetachment is complicated by the likely presence of two energetically competitive electronic states of EuO- populating the ion beam. However, based on the calculated relative energies of the close-lying anion states arising from the 4f7σ6s and 4f6σ6s2 configurations and the relative energies of the one-electron accessible 4f7 and 4f6σ6s 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 4f6σ6s2 7Σ- and 4f7σ6s7Σ- 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 4f6 occupancy.

  12. 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.

  13. 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

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

    PubMed

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

    2015-01-19

    LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu(3+) emission from the nanophosphors are investigated. The optimized Eu(3+) concentration is 35 mol%, and the red emission peaks due to the (5)D0 →(7)FJ (J = 1 and 2) transitions of Eu(3+) ions are further enhanced by energy transfer from a sensitizer pair of Ce(3+) and Tb(3+). The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu(3+) 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 Ce(3+) to Eu(3+) through Tb(3+) results in three times higher Eu(3+) emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu(3+) concentration. Owing to the energy transfer of Ce(3+) → Tb(3+) and Ce(3+) → Tb(3+) → Eu(3+), 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 Eu(3+) concentration. With increasing Eu(3+) 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. 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

  17. Unique Pressure versus Temperature Phase Diagram for Antiferromagnets Eu2Ni3Ge5 and EuRhSi3

    NASA Astrophysics Data System (ADS)

    Nakashima, Miho; Amako, Yasushi; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Nada, Masato; Sugiyama, Kiyohiro; Hagiwara, Masayuki; Haga, Yoshinori; Takeuchi, Tetsuya; Nakamura, Ai; Akamine, Hiromu; Tomori, Keisuke; Yara, Tomoyuki; Ashitomi, Yosuke; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

    2017-03-01

    We studied the magnetic properties of the antiferromagnets Eu2Ni3Ge5 and EuRhSi3 by measuring their electrical resistivity, specific heat, magnetic susceptibility, magnetization, and thermoelectric power, together with the electrical resistivities at high pressures of up to 15 GPa. These compounds have almost divalent Eu ions at ambient pressure and order antiferromagnetically with a successive change in the antiferromagnetic structure at TN = 19 K and T'N = 17 K in Eu2Ni3Ge5, and at TN = 49 K and T'N = 45 K in EuRhSi3. Magnetic field versus temperature (H-T) phase diagrams were constructed for both compounds from the magnetization measurements. The Néel temperature in Eu2Ni3Ge5 was found to increase up to 7 GPa but to decrease continuously with further increasing pressure, without the so-called valence transition. Under a high pressure of 15 GPa, Kondo-like behavior of the electrical resistivity was observed, suggesting the existence of the heavy-fermion state at low temperatures. A similar trend is likely to occur in EuRhSi3. The present P-T phase diagrams for both compounds are the first cases that are reminiscent of the phase diagram of EuCu2(SixGe1-x)2.

  18. Lifetimes of Rydberg states of Eu atoms

    NASA Astrophysics Data System (ADS)

    Jing, Hua; Ye, Shi-Wei; Dai, Chang-Jian

    2015-01-01

    The radiative lifetimes of the Eu 4f76snp (8PJ or 10PJ) Rydberg states with J = 5/2 and 11/2 are investigated with a combination of multi-step laser excitation and pulsed electric field ionization, from which their dependence on the effective principal quantum number is observed. The lifetimes of 21 states are reported along with an evaluation of their experimental uncertainty. The influence of blackbody radiation, due to the oven temperature, on the lifetime of the higher-n states is detected. The non-hydrogen behavior of the investigated states is also observed. Project supported by the National Natural Science Foundation of China (Grant No. 11174218).

  19. Mapping the carbon footprint of EU regions

    NASA Astrophysics Data System (ADS)

    Ivanova, Diana; Vita, Gibran; Steen-Olsen, Kjartan; Stadler, Konstantin; Melo, Patricia C.; Wood, Richard; Hertwich, Edgar G.

    2017-05-01

    While the EU Commission has encouraged Member States to combine national and international climate change mitigation measures with subnational environmental policies, there has been little harmonized effort towards the quantification of embodied greenhouse gas (GHG) emissions from household consumption across European regions. This study develops an inventory of carbon footprints associated with household consumption for 177 regions in 27 EU countries, thus, making a key contribution for the incorporation of consumption-based accounting into local decision-making. Footprint calculations are based on consumer expenditure surveys and environmental and trade detail from the EXIOBASE 2.3 multiregional input-output database describing the world economy in 2007 at the detail of 43 countries, 5 rest-of-the-world regions and 200 product sectors. Our analysis highlights the spatial heterogeneity of embodied GHG emissions within multiregional countries with subnational ranges varying widely between 0.6 and 6.5 tCO2e/cap. The significant differences in regional contribution in terms of total and per capita emissions suggest notable differences with regards to climate change responsibility. The study further provides a breakdown of regional emissions by consumption categories (e.g. housing, mobility, food). In addition, our region-level study evaluates driving forces of carbon footprints through a set of socio-economic, geographic and technical factors. Income is singled out as the most important driver for a region’s carbon footprint, although its explanatory power varies significantly across consumption domains. Additional factors that stand out as important on the regional level include household size, urban-rural typology, level of education, expenditure patterns, temperature, resource availability and carbon intensity of the electricity mix. The lack of cross-national region-level studies has so far prevented analysts from drawing broader policy conclusions that hold

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

    DOE PAGES

    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

  1. Fluence-dependent femtosecond quasiparticle and Eu2 + spin relaxation dynamics in EuFe2(As ,P )2

    NASA Astrophysics Data System (ADS)

    Pogrebna, A.; Mertelj, T.; Cao, G.; Xu, Z. A.; Mihailovic, D.

    2016-10-01

    We investigated temperature- and fluence-dependent dynamics of the time-resolved optical reflectivity in undoped spin-density-wave (SDW) and doped superconducting (SC) EuFe2(As,P ) 2 with emphasis on the ordered Eu2 + spin temperature region. The data indicate that in EuFe2(As,P ) 2 the SDW order coexists at low temperature with the SC and Eu2 +-ferromagnetic order. Increasing the excitation fluence leads to a slow thermal suppression of the Eu2 + spin order due to the crystal-lattice heating on a nanosecond time scale while the SDW order is suppressed nonthermally on a subpicosecond time scale at a higher fluence.

  2. 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.

  3. Commercializing genetically modified crops under EU regulations: objectives and barriers.

    PubMed

    Raybould, Alan; Poppy, Guy M

    2012-01-01

    Agriculture faces serious problems in feeding 9 billion people by 2050: production must be increased and ecosystem services maintained under conditions for growing crops that are predicted to worsen in many parts of the world. A proposed solution is sustainable intensification of agriculture, whereby yields are increased on land that is currently cultivated, so sparing land to deliver other ecosystem services. Genetically modified (GM) crops are already contributing to sustainable intensification through higher yields and lower environmental impacts, and have potential to deliver further significant improvements. Despite their widespread successful use elsewhere, the European Union (EU) has been slow to introduce GM crops: decisions on applications to import GM commodities are lengthy, and decision-making on applications to cultivate GM crops has virtually ceased. Delayed import approvals result in economic losses, particularly in the EU itself as a result of higher commodity prices. Failure to grant cultivation approvals costs EU farmers opportunities to reduce inputs, and results in loss of agricultural research and development from the EU to countries such as the United States and China. Delayed decision-making in the EU ostensibly results from scientific uncertainty about the effects of using GM crops; however, scientific uncertainty may be a means to justify a political decision to restrict cultivation of GM crops in the EU. The problems associated with delayed decision-making will not improve until there is clarity about the EU's agricultural policy objectives, and whether the use of GM crops will be permitted to contribute to achieving those objectives.

  4. Pyrolytic synthesis and luminescence of porous lanthanide Eu-MOF.

    PubMed

    Jin, Guangya; Liu, Zhijian; Sun, Hongfa; Tian, Zhiyong

    2016-02-01

    A lanthanide metal coordination polymer [Eu2(BDC)3(DMSO)(H2O)] was synthesized by the reaction of europium oxide with benzene-1,3-dicarboxylic acid (H2BDC) in a mixed solution of dimethyl sulfoxide (DMSO) and water under hydrothermal conditions. The crystal structure of Eu2(BDC)3(DMSO)(H2O) was characterized by X-ray diffraction (XRD). Thermo-gravimetric analysis of Eu2(BDC)3(DMSO)(H2O) indicated that coordinated DMSO and H2O molecules could be removed to create Eu2(BDC)3(DMSO)(H2O)-py with permanent microporosity, which was also verified by powder XRD (PXRD) and elemental analysis. Both Eu2(BDC)3(DMSO)(H2O) and Eu2(BDC)3(DMSO)(H2O)-py showed mainly Eu-based luminescence and had characteristic emissions in the range 550-700 nm. Copyright © 2015 John Wiley & Sons, Ltd.

  5. EU accession: A policy window opportunity for nursing?

    PubMed

    De Raeve, Paul; Rafferty, Anne-Marie; Bariball, Louise; Young, Ruth; Boiko, Olga

    2017-03-01

    European enlargement has been studied in a wide range of policy areas within and beyond health. Yet the impact of EU enlargement upon one of the largest health professions, nursing, has been largely neglected. This paper aims to explore nurse leadership using a comparative case study method in two former Communist countries, Romania and Croatia. Specifically, it considers the extent to which engagement in the EU accession policy-making process provided a policy window for the leaders to formulate and implement a professional agenda while negotiating EU accession. Findings of qualitative interviews and documentary analysis indicate that the mechanisms used to facilitate the accession process were not successful in achieving compliance with the education standards in the Community Acquis, as highlighted in the criteria on the mutual recognition of professional qualifications set out in Directive 2005/36/EC. EU accession capacity building and accession funds were not deployed efficiently to upgrade Romanian and Croatian nursing education towards meeting EU standards. Conflicting views on accession held by the various nursing stakeholders (nursing regulator, nursing union, governmental chief nurse and the professional association) inhibited the setting of a common policy agenda to achieve compliance with EU standards. The study findings suggest a need to critically review EU accession mechanisms and better align leadership at all governance levels.

  6. Integration of the ferromagnetic insulator EuO onto graphene.

    PubMed

    Swartz, Adrian G; Odenthal, Patrick M; Hao, Yufeng; Ruoff, Rodney S; Kawakami, Roland K

    2012-11-27

    We have demonstrated the deposition of EuO films on graphene by reactive molecular beam epitaxy in a special adsorption-controlled and oxygen-limited regime, which is a critical advance toward the realization of the exchange proximity interaction (EPI). It has been predicted that when the ferromagnetic insulator (FMI) EuO is brought into contact with graphene, an overlap of electronic wave functions at the FMI/graphene interface can induce a large spin splitting inside the graphene. Experimental realization of this effect could lead to new routes for spin manipulation, which is a necessary requirement for a functional spin transistor. Furthermore, EPI could lead to novel spintronic behavior such as controllable magnetoresistance, gate tunable exchange bias, and quantized anomalous Hall effect. However, experimentally, EuO has not yet been integrated onto graphene. Here we report the successful growth of high-quality crystalline EuO on highly oriented pyrolytic graphite and single-layer graphene. The epitaxial EuO layers have (001) orientation and do not induce an observable D peak (defect) in the Raman spectra. Magneto-optic measurements indicate ferromagnetism with a Curie temperature of 69 K, which is the value for bulk EuO. Transport measurements on exfoliated graphene before and after EuO deposition indicate only a slight decrease in mobility.

  7. 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.

  8. Optical properties of Eu2+ doped antipervoskite fluoride single crystals

    NASA Astrophysics Data System (ADS)

    Daniel, D. Joseph; Nithya, R.; Ramasamy, P.; Madhusoodanan, U.

    2013-02-01

    Single crystals of pure and Eu2+ doped LiBaF3 have been grown from melt by using a vertical Bridgman-Stockbarger method. Absorption and luminescence spectra for pure and rare-earth-doped LiBaF3 were studied. At ambient conditions the photoluminescence spectra consisted of sharp lines peaked at ˜359 nm attributed to the 6P7/2→8S7/2 transitions in the 4f7 electronic configuration of Eu2+ and a broad band extending between 370 and 450 nm attributed to Eu2+ trapped exciton recombination. The effect of 60Co gamma irradiation has also been investigated.

  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. 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.

  11. 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

  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. The Multiplex Network of EU Lobby Organizations

    PubMed Central

    Zeng, An; Battiston, Stefano

    2016-01-01

    The practice of lobbying in the interest of economic or social groups plays an important role in the policy making process of most economies. While no data is available at this stage to examine the success of lobbies in exerting influence on specific policy issues, we perform a first systematic multi-layer network analysis of a large lobby registry. Here we focus on the domains of finance and climate and we combine information on affiliation and client relations from the EU transparency register with information about shareholding and interlocking directorates of firms. We find that the network centrality of lobby organizations has no simple relation with their lobbying budget. Moreover, different layers of the multiplex network provide complementary information to characterize organizations’ potential influence. At the aggregate level, it appears that while the domains of finance and climate are separated on the layer of affiliation relations, they become intertwined when economic relations are considered. Because groups of interest differ not only in their budget and network centrality but also in terms of their internal cohesiveness, drawing a map of both connections across and within groups is a precondition to better understand the dynamics of influence on policy making and the forces at play. PMID:27792734

  14. The Multiplex Network of EU Lobby Organizations.

    PubMed

    Zeng, An; Battiston, Stefano

    2016-01-01

    The practice of lobbying in the interest of economic or social groups plays an important role in the policy making process of most economies. While no data is available at this stage to examine the success of lobbies in exerting influence on specific policy issues, we perform a first systematic multi-layer network analysis of a large lobby registry. Here we focus on the domains of finance and climate and we combine information on affiliation and client relations from the EU transparency register with information about shareholding and interlocking directorates of firms. We find that the network centrality of lobby organizations has no simple relation with their lobbying budget. Moreover, different layers of the multiplex network provide complementary information to characterize organizations' potential influence. At the aggregate level, it appears that while the domains of finance and climate are separated on the layer of affiliation relations, they become intertwined when economic relations are considered. Because groups of interest differ not only in their budget and network centrality but also in terms of their internal cohesiveness, drawing a map of both connections across and within groups is a precondition to better understand the dynamics of influence on policy making and the forces at play.

  15. MORB Mantle Hosts the Missing Eu in the Continental Crust

    NASA Astrophysics Data System (ADS)

    Niu, Y.; O'Hara, M. J.

    2004-12-01

    The continental crust (CC) is an important geochemical reservoir. The origin and evolution of CC remains debated [1-13]. Estimation of bulk CC composition is model dependent [1-8,12]. A reliable upper CC composition has been obtained from shales and other fine-grained sedimentary rocks [1,2,15,16] due to the mixing/homogenization effects of sedimentary processes [14-16]. The upper CC has a negative Eu anomaly (NEuA or Eu/Eu* < 1), 0.65, which points to a missing Eu storage. The upper CC is <10km thick and cannot represent the bulk CC [1-3], which has a mean thickness of ˜36km. To determine the composition of deep CC is required, but the task is hard [1-3]. The approach of combining geochemical data on deep crustal rocks (xenoliths and locally exposed amphibolites and granulites) with seismic and heat flow data to estimate the average deep CC composition is creative [1-4,12]. As some granulites show Eu/Eu* > 1, the missing Eu in the upper CC may be in the deep CC. Indeed, the NEuA in the upper CC is largely reduced in model bulk CC compositions: 0.829 [4], 0.962 [1], 0.974 [3]. By assuming mantle derived igneous rocks display no Eu anomaly [1,12], the upper CC NEuA would come from intracrustal differentiation. For example, the granitic upper CC resulted from anatexis of mafic rocks in the deep CC with Plag as a residual phase (holding Eu) in the granulite residues [1-4,12]. This interpretation is sensible, but the protoliths of most of these granulites are found to be underplated mantle melts [1,17-19]. The NEuA ( ˜0.8) and the more felsic nature of bulk CC composition in China encouraged the authors [12] to suggest that the more mafic lower CC rocks were tectonically removed. We show that high quality data on 306 fresh MORB glass samples (2-10 wt% MgO) from the Pacific and Atlantic [20-25] exhibit varying Eu/Eu* (0.68-1.18) and significant correlations: R[MgO-Eu/Eu*] = 0.876, R[MgO-Sr/Sr*] = 0.809 and R[Eu/Eu*-Sr/Sr*] = 0.875. 148 samples show Eu/Eu* > 1. For Eu/Eu

  16. Luminescence studies of Eu-doped YBO3 host

    NASA Astrophysics Data System (ADS)

    Nair, Ramya G.; Nigam, Sandeep; Sudarsan, V.; Dhabekar, B. S.; Vatsa, R. K.

    2016-05-01

    Highly crystalline phase of YBO3:Eu3+ phosphors were prepared by solid state reaction. The phosphor shows characteristic 5D0→7F1 (J = 1, 2, 3, 4) transition for Eu3+. Phase purity, and emission intensity increases with increase in the annealing temperature and corresponding Eu-O charge transfer band shows blue shift in excitation spectrum. Color purity, determined in terms of R/O ratio, was found to be 1.42 (CIE color coordinates x = 0.62, y = 0.36). According to the luminescence decay analysis the 5D0 level of Eu3+ lifetime is around 5ms and quantum efficiency is 72%. Thermo-luminescence (TL) spectra of the sample reveal three broad peaks between 80 and 240°C.

  17. EU member state government contribution to alternative methods.

    PubMed

    Taylor, Katy

    2014-01-01

    Article 47 of the new EU Directive 2010/63/EU on the protection of animals used for scientific purposes requires national governments to contribute to the development and promotion of alternative methods. A recent survey of EU member states found that reported funding of alternative (3Rs) methods totalled € 18.7 million in 2013, provided by only seven countries (Austria, Belgium, Denmark, Finland, Germany, Sweden, and the UK). There were indications that the contributions of some of these countries have increased since the implementation of the new Directive. However, funding of alternatives is between 0 and 0.036% of national science R&D expenditure and nearly half of the countries that responded reported that they do not specifically contribute. Data (and, by assumption, financial contribution) remains unavailable from half of the member states across the EU, regardless of the method of collection.

  18. Aqueous EuII-containing complex with bright yellow luminescence

    PubMed Central

    Kuda-Wedagedara, Akhila N. W.; Wang, Chengcheng; Martin, Philip D.; Allen, Matthew J.

    2015-01-01

    EuII-containing materials have unique luminescence, redox, and magnetic properties that have potential applications in optoelectronics, sensors, and imaging. Here, we report the synthesis and characterization of EuII-containing aza-222 cryptate that displays yellow luminescence and a quantum yield of 26% in aqueous media. The crystal structure reveals a staggered hulahoop geometry. Both solid-state and solution-phase data are presented that indicate that the high quantum yield is a result of the absence of OH oscillators in the inner sphere of the complex. We expect that EuII-containing aza-222 cryptate is a step toward EuII-containing luminescent materials that can be used in a variety of applications including biological imaging. PMID:25853298

  19. Optical characterization of Eu3+ doped ZnO nanocomposites.

    PubMed

    Grandhe, Bhaskar Kumar; Bandi, Vengala Rao; Jang, Kiwan; Lee, Ho-Sueb; Shin, Dong-Soo; Yi, Soung-Soo; Jeong, Jung-Hyun

    2013-11-01

    A rare-earth metal ion (Eu3+) doped ZnO nanocomposites have been successfully synthesized by employing wet chemical procedure using multi-wall carbon nanotubes (MWCNT's) as removable template. The preparation was carried out by immersing empty and dried MWCNT's in a stoichiometric composition of zinc nitrate and europium nitrate solution followed by filtration and sintering. The synthesized Eu3+ doped ZnO nanocomposites were characterized by means of different characterization techniques namely XRD, SEM, EDS, FT-IR and Raman spectroscopy. The XRD profile of the Eu3+ doped ZnO nanocomposites indicated its hexagonal nature while the photoluminescent analysis reveals that the prepared nanocomposite exhibits a strong red emission peak at 619 nm due to 5D0 --> 7F2 forced electric dipole transition of Eu3+ ions. Such luminescent materials are expected to find potential applications in display devices.

  20. 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.

  1. 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.

  2. Unusual Mixed Valence of Eu in Two Materials-EuSr2Bi2S4F4 and Eu2SrBi2S4F4: Mössbauer and X-ray Photoemission Spectroscopy Investigations.

    PubMed

    Haque, Zeba; Thakur, Gohil Singh; Parthasarathy, Rangasamy; Gerke, Birgit; Block, Theresa; Heletta, Lukas; Pöttgen, Rainer; Joshi, Amish G; Selvan, Ganesan Kalai; Arumugam, Sonachalam; Gupta, Laxmi Chand; Ganguli, Ashok Kumar

    2017-02-28

    We have synthesized two new Eu-based compounds, EuSr2Bi2S4F4 and Eu2SrBi2S4F4, which are derivatives of Eu3Bi2S4F4, an intrinsic superconductor with Tc = 1.5 K. They belong to a tetragonal structure (SG: I4/mmm, Z = 2), similar to the parent compound Eu3Bi2S4F4. Our structural and (151)Eu Mössbauer spectroscopy studies show that, in EuSr2Bi2S4F4, Eu-atoms exclusively occupy the crystallographic 2a-sites. In Eu2SrBi2S4F4, 2a-sites are fully occupied by Eu-atoms and the other half of Eu-atoms and Sr-atoms together fully occupy 4e-sites in a statistical distribution. In both compounds Eu atoms occupying the crystallographic 2a-sites are in a homogeneous mixed valent state ∼2.6-2.7. From our magnetization studies in an applied H ≤ 9 T, we infer that the valence of Eu-atoms in Eu2SrBi2S4F4 at the 2a-sites exhibits a shift toward 2+. Our XPS studies corroborate the occurrence of valence fluctuations of Eu and after Ar-ion sputtering show evidence of enhanced population of Eu(2+)-states. Resistivity measurements, down to 2 K, suggest a semimetallic nature for both compounds.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Electron spin resonance in Eu-based iron pnictides

    NASA Astrophysics Data System (ADS)

    Krug von Nidda, H.-A.; Kraus, S.; Schaile, S.; Dengler, E.; Pascher, N.; Hemmida, M.; Eom, M. J.; Kim, J. S.; Jeevan, H. S.; Gegenwart, P.; Deisenhofer, J.; Loidl, A.

    2012-09-01

    The phase diagrams of EuFe2-xCoxAs2 (0≤x≤0.4) and EuFe2As2-yPy (0≤y≤0.43) are investigated by Eu2+ electron spin resonance (ESR) in single crystals. From the temperature dependence of the linewidth ΔH(T) of the exchange narrowed ESR line, the spin-density wave (SDW) (TTSDW) are clearly distinguished. At T>TSDW the isotropic linear increase of the linewidth is driven by the Korringa relaxation which measures the conduction-electron density of states at the Fermi level. For T0.2 and y>0.3 it remains nearly constant. Comparative ESR measurements on single crystals of the Eu diluted SDW compound Eu0.2Sr0.8Fe2As2 and superconducting (SC) Eu0.22Sr0.78Fe1.72Co0.28As2 corroborate the leading influence of the ligand field on the Eu2+ spin relaxation in the SDW regime as well as the Korringa relaxation in the normal metallic regime. A coherence peak is not detected in the latter compound below Tc=21 K, which is in agreement with the expected complex anisotropic SC gap structure. In contrast, indications for phase coexistence and BCS-type superconductivity are found in EuFe2As1.57P0.43.

  8. Magnetic properties of EuCr2Al20

    NASA Astrophysics Data System (ADS)

    Swatek, Przemysław; Kaczorowski, Dariusz

    2016-10-01

    Polycrystalline sample of EuCr2Al20 was studied by means of x-ray powder diffraction, magnetization, electrical resistivity and heat capacity measurements. The compound was found to order antiferromagnetically at TN = 4.8 K due to the magnetic moments carried on divalent of Eu ions. The experimental findings are supported by the results of ab-initio band structure calculations.

  9. 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

  10. EPR and luminescence studies of the radiation induced Eu2+ centers in the EuAl3(BO3)4 single crystals

    NASA Astrophysics Data System (ADS)

    Prokhorov, A. A.; Chernush, L. F.; Babin, V.; Buryi, M.; Savchenko, D.; Lančok, J.; Nikl, M.; Prokhorov, A. D.

    2017-04-01

    We have studied the X-ray irradiated EuAl3(BO3)4 single crystals by means of luminescence and electron paramagnetic resonance (EPR) spectroscopy. It was found that the X-ray irradiation modifies the color of the EuAl3(BO3)4 crystal and leads to the formation of a stable Eu2+ centers from the Eu3+ centers located in a host matrix. Annealing of the crystal at 600 °C leads to the restoration of the original color and the disappearance of Eu2+ centers. The EPR and luminescence spectra of the Eu2+ ion were studied in a wide temperature range. The angular dependence of Eu2+ EPR spectra is described by an axial spin Hamiltonian characterized by the spin of S = 7/2 with the following parameters: gz = gx = 1.991 (1); b20 = -267,86 (16)*10-4cm-1; b40 = -4,20 (8)* 10-4cm-1; b60 = 0,37 (13)* 10-4cm-1; A (151) = 31,4 (3)* 10-4cm-1; A (153) = 13,9 (3)* 10-4cm-1. Based on the comparison of spin Hamiltonian parameters of Eu2+ and Gd3+ ions, it was concluded that Eu2+ ion located at the Eu3+ site in the EuAl3(BO3)4 crystal lattice. Within the framework of the superposition model, the distortions introduced to the local environment by the Eu2+ and Gd3+ ions were analyzed. In the luminescence spectra, the bands associated with the Eu2+ and Eu3+ ions are detected. The photoluminescence decay kinetics of Eu3+-related emission (614 nm) has a single-exponential character, whereas the Eu2+-related band (323 nm) possess more complicated decay kinetics behavior that may point to the Eu2+ excited state ionization and its delayed recombination.

  11. Radiation stability of CsBr:Eu needle image plates

    NASA Astrophysics Data System (ADS)

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

    2009-10-01

    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 Eu2+-containing precursor CsEuBr3 for the doping in the manufacturing process.

  12. 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.

  13. 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.

  14. Luminescence in Li₃ Al ₂ (PO₄)₃ :Eu(2+).

    PubMed

    Shinde, K N; Park, K

    2013-01-01

    A series of efficient Li₃ Al ₂ (PO₄)₃ :Eu(2+) novel phosphors were synthesized by the facile combustion method. The effects of dopant on the luminescence behavior of Li₃ Al ₂ (PO₄)₃ phosphor were also investigated. The phosphors were characterized by X-ray diffraction, field emission scanning electron microscope and photoluminescence techniques. The result shows that all samples can be excited efficiently by near-ultraviolet excitation under 310 nm. The emission was observed for Li₃ Al ₂ (PO₄)₃ :Eu(2+) phosphor at 425 nm, which corresponded to the d → f transition. The concentration quenching of Eu(2+) was observed in Li₃ Al ₂ (PO₄)₃ :Eu(2+) when the Eu concentration was at 0.5 mol%. The prepared powders exhibited intense blue emission at the 425 nm owing to the Eu(2+) ion by Hg-free excitation at 310 nm (i.e., solid-state lighting excitation). Consequently, the availability of such a phosphor will significantly help in the development of blue-emitting solid-state lighting applications. Copyright © 2012 John Wiley & Sons, Ltd.

  15. Implementing SDG 15.3 on Land Degradation Neutrality in the EU and EU Member States

    NASA Astrophysics Data System (ADS)

    Wunder, Stephanie; Starke, Sue Martina; Frelih-Larsen, Ana; Kaphengst, Timo

    2017-04-01

    The continuing degradation of land and soils is a severe threat to the provision of ecosystem services and economic development. Sustainable use of land and soils are therefore an integral part of the "Agenda 2030" with its 17 Sustainable Development Goals (SDGs) and 169 targets adopted by the UNGeneral Assembly in September 2015. The SDGs provide new opportunities for an ambitious and integrated environmental policy worldwide and in the EU. Among the many relevant targets that directly or indirectly address soils (such as goals on zero hunger, well being, clean energy, climate change, water and sustainable cities), target 15.3 that aims to achieve "a land degradation-neutral world" by 2030 is the most relevant. The concept of "Land Degradation Neutrality" (LDN) is not only about halting the loss of healthy and fertile land, but also actively reversing degradation by restoring land in order to counterbal-ance losses that cannot be avoided. It is a very ambitious target but due to a lack of balancing mechanisms for degradation and restoration in most countries also a new concept. Land Degra-dation Neutrality therefore both needs a scientific conceptual framework as well as a political debate about its implementation and development of instruments. In the EU and its Member States, this debate can also serve as a catalyst to revive the discussion on a common soil policy in Europe after the withdrawal of the proposal for a soil framework directive in 2014. To analyze options for the implementation of target 15.3 in Germany and Europe the research project "Implementing the Sustainable Development Goals on Soils in Germany" (http://ecologic.eu/12876) is currently carried out by the Ecologic Institute on behalf of the Ger-man Environment Agency (UBA) and the German Federal Environment Ministry (BMUB). The project will run until spring 2017 and the session "European Environmental Policies and Sustainability" at the EGU will be an ideal opportunity to present the final

  16. Temperature-composition phase diagrams of Gd-doped EuO and EuS

    NASA Astrophysics Data System (ADS)

    An, Joonhee; Barabash, S.; Belashchenko, K.

    2009-03-01

    We have computed the temperature-phase diagram of Eu1-xGdxO alloys by combining density functional theory in the generalized-gradient approximation with Hubbard U correction on f-orbitals with the regular cluster expansion and Monte-Carlo approach. The cluster expansion fit has been performed with varying numbers of distinct cluster types until the formal cross-validation score is minimized. Our results indicate that (i) pair interactions are relatively stronger than other cluster types, (ii) the pair terms decay rapidly with distance up to 10 å, (iii) the pair terms are attractive for direct interactions between cations and repulsive for indirect interactions through anions, and (iv) the calculated convex hull is asymmetric about x=0.5, displaying more deep ground states in Eu-rich regions than in Gd-rich regions. The asymmetry of the convex hull may imply relative instability of Gd-rich compounds, as was shown by previously-reported experimental difficulties to make Gd-rich compounds. A comparison with a similar binary system - sulfur replacing oxygen - is made, showing that both oxides and sulphides are dominated by deformation interaction. The sulphides have a marginal tendency to phase-separate into pure compounds at low temperatures, whereas the oxides tend to order.

  17. EU assessment of enterococci as feed additives.

    PubMed

    Becquet, Philippe

    2003-12-01

    Particular micro-organisms such as enterococcal strains are used as probiotics in feed. Observations indicate a positive effect of such strains on the gut flora, especially for young animals or during feed transition phases. This favourable effect is perceived by the farmers as a means of maintenance of the health status of the animals (e.g. less diarrhoea) and results in significant improvement of animal performance. Micro-organisms have been used since the end of the 1980s in animal feeds and were strictly regulated in 1993, when they were introduced under the scope of Council Directive 70/524/EEC of 23 November 1970 on additives in animal nutrition on feed additives. After a transition period, which ended in the year 2000, every microbial strain must now be assessed by the EU bodies and authorised by a Commission Regulation, before it can be placed on the market for use in feedingstuffs. Council Directive 70/524/EEC on feed additives is based on three main principles: (1) pre-market authorisation, (2) positive list principle, and (3) thorough risk assessment of the effect of a particular strain on human and animal health as well as on the environment. Therefore, before introducing a new enterococcal strain preparation or promote a new use of an approved product, a dossier has to be submitted to the authorities, following the guidelines, as published in Commission Directive 94/40/EEC [Commission Directive 94/40/EC of 22 July 1994 amending Council Directive 87/153/EEC fixing guidelines for the assessment of additives in animal nutrition]. These guidelines contain detailed evaluation methods. The safety requirements refer to (1) the target animal categories, (2) the consumer and the environment (presence of toxins and virulence factors as well as antibiotic resistance and transferability are assessed), and (3) the workers, based on requirements of Council Directive 89/391/EEC.

  18. [Experimental animal research in the EU legislation].

    PubMed

    Bolliger, Gieri

    2002-01-01

    The legislation of the European Union captures experimental animal research only in part. Binding standards can be found in various legal records of the community-legislation, and in particular in the so-called guideline for animal experimentation 86/609/EWG. But these guidelines do not represent an actual animal protection measure but rather one of harmonisation with the primary goal of unification of the regulations of the participating states in order to prevent distortions of competition and trade barriers which could harm the common market. Although the guideline contains some practicable approaches in the direction of an up-to-date animal experimentation law, it only defines general goals which allows for considerable leeway in national implementation within the individual EU countries, and it has only a limited area of legal operation. On the one hand, only vertebrae are being included, and on the other, the law is only being applied in the area of applied research and protects only animals used in product- and substance-development or test procedures as well as those used in the framework of environmental protection. Various important fields of research are thus not subject to a common regulation and are assigned to national regulation. This concerns animal experimentation in education and training or for military or so-called defence-relevant medical purposes and, in particular, the whole area of basic research including the field of genetic engineering in animals with it's growing significance. The guideline is in need of widening it's scope of application as well as of various adjustments to recent scientific findings and developments in order to become suitable as a more restrictive animal protection law on the community level. It could also be desirable to include animal protection into the catalogue of community-goals in order to make it an independent component of the politics of the Union and to establish the groundwork for a decree of comprehensive

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

    DOE PAGES

    Liu, Feng; Meltzer, Richard S.; Li, Xufan; ...

    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

  20. Nuclear spin coherence properties of 151Eu3+ and 153Eu3+ in a Y2O3 transparent ceramic

    NASA Astrophysics Data System (ADS)

    Karlsson, J.; Kunkel, N.; Ikesue, A.; Ferrier, A.; Goldner, P.

    2017-03-01

    We have measured inhomogeneous linewidths and coherence times (T 2) of nuclear spin transitions in a Eu3+ :Y2O3 transparent ceramic by an all-optical spin echo technique. The nuclear spin echo decay curves showed a strong modulation which was attributed to interaction with Y nuclei in the host. The coherence time of the 29 MHz spin transition in 151Eu3+ was 16 ms in a small applied magnetic field. Temperature dependent measurements showed that the coherence time was constant up to 18 K and was limited by spin-lattice relaxation for higher temperatures. Nuclear spin echoes in 153Eu3+ gave much weaker signals than for the case of 151Eu3+ . The spin coherence time for the 73 MHz spin transition in 153Eu3+ was estimated to 14 ms in a small magnetic field. The study shows that the spin transitions of ceramic Eu3+ :Y2O3 have coherence properties comparable to the best rare-earth-doped materials available.

  1. Effect of Eu magnetism on the electronic properties of the candidate Dirac material EuMnBi2

    NASA Astrophysics Data System (ADS)

    May, Andrew F.; McGuire, Michael A.; Sales, Brian C.

    2014-08-01

    The crystal structure and physical properties of the layered material EuMnBi2 have been characterized by measurements on single crystals. EuMnBi2 is isostructural with the Dirac material SrMnBi2 based on single-crystal x-ray diffraction, crystallizing in the I4/mmm space group (No. 139). Magnetic susceptibility measurements suggest antiferromagnetic (AFM) ordering of moments on divalent Eu ions near TN=22 K. For low fields, the ordered Eu moments are aligned along the c axis, and a spin flop is observed near 5.4 T at 5 K. The moment is not saturated in an applied field of 13 T at 5 K, which is uncommon for compounds containing Eu2+. The magnetic behavior suggests an anisotropy enhancement via interaction between Eu and the Mn moments that appear to be ordered antiferromagnetically below ≈310 K. A large increase in the magnetoresistance is observed across the spin flop, with absolute magnetoresistance reaching ≈650% at 5 K and 12 T. Hall effect measurements reveal a decrease in the carrier density below TN, which implies a manipulation of the Fermi surface by magnetism on the sites surrounding the Bi square nets that lead to Dirac cones in this family of materials.

  2. Strain-Induced Enhancement of Eu3+ Emission in Red Phosphor NaMgPO4:Eu3+, Al3+

    NASA Astrophysics Data System (ADS)

    Gao, Yong; Long, Qiwei; Nong, Rong; Wang, Tianman; Huang, Yingheng; Liao, Sen; Zhang, Huaxin

    2017-02-01

    A series of (NaMgPO4)0.98- x : {Eu}_{0.02}^{3 + }, {Al}x^{3 + } phosphors were prepared by the solid-state method. X-ray powder diffraction results confirm that the samples contain mixture phases of crystals. The doped effect of Al3+ on the photoluminescence properties of (NaMgPO4)0.98- x : {Eu}_{0.02}^{3 + }, {Al}x^{3 + } phosphors is discussed. The results indicate that two dependent curves of emission relative intensity and strain on Al3+ doping concentration are all Gaussian curves, and a high correlation is observed between emission relative intensity of Eu3+ and strain caused by Al3+. In other words, emission relative intensity of Eu3+ is enhanced with the increase of the strain. The enhanced mechanism of the strain is discussed. In addition, (NaMgPO4)0.98- x : {Eu}_{0.02}^{3 + }, {Al}x^{3 + } phosphors are electric dipole-dominated transition red phosphors. The optimal molar concentration of Al3+ for the samples is 9%, which (NaMgPO4)0.89: {Eu}_{0.02}^{3 + }, {Al}_{0.09}^{3 + } is a potential candidate as the red-emitting phosphor for ultraviolet-based white light-emitting diodes.

  3. 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

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

    PubMed

    Chanda, Rupa

    2011-02-10

    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. 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. 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. The paper concludes that although there are several promising areas for India-EU relations in health services, it will be

  5. Fermi Surface Properties of Eu-Divalent and Eu-Trivalent Electronic States with the AuCu3-type Cubic Structure

    NASA Astrophysics Data System (ADS)

    Nakamura, Ai; Takeuchi, Tetsuya; Tatetsu, Yasutomi; Maehira, Takahiro; Harima, Hisatomo; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

    2015-03-01

    The electronic states in EuBi3 and EuPd3 are known to be Eu-divalent and Eu- trivalent, respectively, from the previous studies using polycrystal samples. In the present study, we succeeded in growing high-quality single crystals, and carried out the de Haas-van Alphen (dHvA) measurements and energy band calculations to clarify the Fermi surface properties.

  6. Blue emission of Eu2+-doped translucent alumina

    DOE PAGES

    Yang, Yan; Zhang, Lihua; Kisslinger, Kim; ...

    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

  7. Pesticide authorization in the EU-environment unprotected?

    PubMed

    Stehle, Sebastian; Schulz, Ralf

    2015-12-01

    Pesticides constitute an integral part of high-intensity European agriculture. Prior to their authorization, a highly elaborated environmental risk assessment is mandatory according to EU pesticide legislation, i.e., Regulation (EC) No. 1107/2009. However, no field data-based evaluation of the risk assessment outcome, i.e., the regulatory acceptable concentrations (RACs), and therefore of the overall protectiveness of EU pesticide regulations exists. We conducted here a comprehensive meta-analysis using peer-reviewed literature on agricultural insecticide concentrations in EU surface waters and evaluated associated risks using the RACs derived from official European pesticide registration documents. As a result, 44.7 % of the 1566 cases of measured insecticide concentrations (MICs) in EU surface waters exceeded their respective RACs. It follows that current EU pesticide regulations do not protect the aquatic environment and that insecticides threaten aquatic biodiversity. RAC exceedances were significantly higher for insecticides authorized using conservative tier-I RACs and for more recently developed insecticide classes, i.e., pyrethroids. In addition, we identified higher risks, e.g., for smaller surface waters that are specifically considered in the regulatory risk assessment schemes. We illustrate the shortcomings of the EU regulatory risk assessment using two case studies that contextualize the respective risk assessment outcomes to field exposure. Overall, our meta-analysis challenges the field relevance and protectiveness of the regulatory environmental risk assessment conducted for pesticide authorization in the EU and indicates that critical revisions of related pesticide regulations and effective mitigation measures are urgently needed to substantially reduce the environmental risks arising from agricultural insecticide use.

  8. Improved red emission by codoping Li+ in ZnWO4:Eu3+ phosphors

    NASA Astrophysics Data System (ADS)

    Chen, Guiqiang; Wang, Fengli; Yu, Jie; Zhang, Haisheng; Zhang, Xiao

    2017-01-01

    ZnWO4:Eu3+ and ZnWO4:Eu3+/Li+ phosphors have been synthesized successfully by a microwave-assist hydrothermal process. The phase, morphology and luminescent properties are investigated carefully. The XRD and FTIR results indicate that ZnWO4:Eu3+ and ZnWO4:Eu3+/Li+ phosphors have the monoclinic phase. The SEM images indicate that ZnWO4:Eu3+ and ZnWO4:Eu3+/Li+ phosphors are cubes with average particle size about 1 μm. Under the excitation at 395 nm, ZnWO4:Eu3+ and ZnWO4:Eu3+/Li+ phosphors show emission bands originating from the 5D0 → 7Fj (j = 0, 1, 2 and 3) transitions of Eu3+ ions. The Li+ ion acts as charge compensator and results in the enhancement of emission intensity.

  9. 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

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

    PubMed

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

    2014-11-01

    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. 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. 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. 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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  11. Sexual and reproductive health of migrants: does the EU care?

    PubMed

    Keygnaert, Ines; Guieu, Aurore; Ooms, Gorik; Vettenburg, Nicole; Temmerman, Marleen; Roelens, Kristien

    2014-02-01

    The European Union (EU) refers to health as a human right in many internal and external communications, policies and agreements, defending its universality. In parallel, specific health needs of migrants originating from outside the EU have been acknowledged. Yet, their right to health and in particular sexual and reproductive health (SRH) is currently not ensured throughout the EU. This paper reflects on the results of a comprehensive literature review on migrants' SRH in the EU applying the Critical Interpretive Synthesis review method. We highlight the discrepancy between a proclaimed rights-based approach to health and actual obstacles to migrants' attainment of good SRH. Uncertainties on entitlements of diverse migrant groups are fuelled by unclear legal provisions, creating significant barriers to access health systems in general and SRH services in particular. Furthermore, the rare strategies addressing migrants' health fail to address sexual health and are generally limited to perinatal care and HIV screening. Thus, future European public health policy-making should not only strongly encourage its Member States to ensure equal access to health care for migrants as for EU citizens, but also promote migrants' SRH effectively through a holistic and inclusive approach in SRH policies, prevention and care.

  12. 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.

  13. EuPathDB: a portal to eukaryotic pathogen databases

    PubMed Central

    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

  14. 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.

  15. Thermodynamic Assessment of EuCl3-MgCl2 and EuCl3-BaCl2 Systems

    NASA Astrophysics Data System (ADS)

    Wang, Yu; Sun, Yimin

    2011-09-01

    Using the CALPHAD technique, an assessment of the binary EuCl3-MgCl2 and EuCl3-BaCl2 systems has been carried out in this study. The modified quasi-chemical model was defined to describe the Gibbs energies of the liquid phases, and the model parameters were optimized from the experimental phase diagram data. The phase diagrams and enthalpies of mixing of the EuCl3-MgCl2 and EuCl3-BaCl2 systems were calculated. The calculated results by the present method agree well with the experimental data. The Gibbs energies of formation of Mg3Eu2Cl12, Ba3Eu2Cl12, and Ba2Eu3Cl13 from the pure components were predicted.

  16. Proceedings of the EuBIC Winter School 2017.

    PubMed

    Willems, Sander; Bouyssié, David; David, Matthieu; Locard-Paulet, Marie; Mechtler, Karl; Schwämmle, Veit; Uszkoreit, Julian; Vaudel, Marc; Dorfer, Viktoria

    2017-05-24

    The 2017 EuBIC Winter School was held from January 10th to January 13th 2017 in Semmering, Austria. This meeting gathered international researchers in the fields of bioinformatics and proteomics to discuss current challenges in data analysis and biological interpretation. This article outlines the scientific program and exchanges that took place on this occasion and presents the current challenges of this ever-growing field. The EUPA bioinformatics community (EuBIC) organized its first winter school in January 2017. This successful event illustrates the growing need of the bioinformatics community in proteomics to gather and discuss current and future challenges in the field. In addition to the organization of yearly meetings, the young and active EuBIC community aims to develop new collaborative open source projects, spread bioinformatics knowledge in Europe, and actively promote data sharing through public repositories. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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. Copyright © 2014 John Wiley & Sons, Ltd.

  18. 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.

  19. Rights of dental patients in the EU - a legal assessment.

    PubMed

    Van den Bossche, Anne-Marie; Ploscar, Paula

    2012-11-30

    This contribution presents the legal framework for intra-European mobility of dental patients. After presenting the EU competences in respect of healthcare and a brief look into the various routes of patient mobility, the article sets out the rules for access to dental care, treatment abroad and reimbursement through social security. In addition, we focus on the impact of European Union (EU) law upon national systems in respect of professional insurance, complaints procedures and information mechanisms. In conclusion, we reflect on the development in EU law of an independent set of rights to cross-border dental care and its consequences for financing and reimbursement of care, as well as for national practices in respect of professional liability and insurance.

  20. Enhancing the luminescence of Eu(3)(+) /Eu(2)(+) ion-doped hydroxyapatite by fluoridation and thermal annealing.

    PubMed

    Van, Hoang Nhu; Tam, Phuong Dinh; Kien, Nguyen Duc Trung; Huy, Pham Thanh; Pham, Vuong-Hung

    2016-12-28

    This paper reports a novel way for the synthesis of a europium (Eu)-doped fluor-hydroxyapatite (FHA) nanostructure to control the luminescence of hydroxyapatite nanophosphor, particularly, by applying optimum fluorine concentrations, annealed temperatures and pH value. The Eu-doped FHA was made using the co-precipitation method followed by thermal annealing in air and reducing in a H2 atmosphere to control the visible light emission center of the nanophosphors. The intensities of the OH(-) group decreased with the increasing fluorine concentrations. For the specimens annealed in air, the light emission center of the nanophosphor was 615 nm, which was emission from the Eu(3)(+) ion. However, when they were annealed in reduced gas (Ar + 5% H2 ), a 448 nm light emission center from the Eu(2)(+) ion of FHA was observed. The presence of fluorine in Eu-doped FHA resulted in a significant enhancement of nanophosphor luminescence, which has potential application in light emission and nanomedicine.

  1. Migrant's access to preventive health services in five EU countries.

    PubMed

    Rosano, Aldo; Dauvrin, Marie; Buttigieg, Sandra C; Ronda, Elena; Tafforeau, Jean; Dias, Sonia

    2017-08-23

    Preventive health services (PHSs) form part of primary healthcare with the aim of screening to prevent disease. Migrants show significant differences in lifestyle, health beliefs and risk factors compared with the native populations. This can have a significant impact on migrants' access to health systems and participation in prevention programmes. Even in countries with widely accessible healthcare systems, migrants' access to PHSs may be difficult. The aim of the study was to compare access to preventive health services between migrants and native populations in five European Union (EU) countries. Information from Health Interview Surveys of Belgium, Italy, Malta, Portugal and Spain were used to analyse access to mammography, Pap smear tests, colorectal cancer screening and flu vaccination among migrants. The comparative risk of not accessing PHSs was calculated using a mixed-effects multilevel model, adjusting for potential confounding factors (sex, education and the presence of disability). Migrant status was defined according to citizenship, with a distinction made between EU and non-EU countries. Migrants, in particular those from non-EU countries, were found to have poorer access to PHSs. The overall risk of not reporting a screening test or a flu vaccination ranged from a minimum of 1.8 times (colorectal cancer screening), to a high of 4.4 times (flu vaccination) for migrants. The comparison among the five EU countries included in the study showed similarities, with particularly limited access recorded in Italy and in Belgium for non-EU migrants. The findings of this study are in accordance with evidence from the scientific literature. Poor organization of health services, in Italy, and lack of targeted health policies in Belgium may explain these findings. PHSs should be responsive to patient diversity, probably more so than other health services. There is a need for diversity-oriented, migrant-sensitive prevention. Policies oriented to removing

  2. 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.

  3. 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.

  4. Energy transfer between Eu3+ ions in calcium diborate glasses

    NASA Astrophysics Data System (ADS)

    Lavín, V.; Martín, I. R.; Rodríguez-Mendoza, U. R.; Rodríguez, V. D.

    1999-11-01

    The evolution of the 5D0icons/Journals/Common/to" ALT="to" ALIGN="TOP"/> 7F0 emission of Eu3+ ions in calcium diborate glasses has been analysed using time resolved fluorescence line narrowing measurements in order to give a complete view of the energy transfer processes between these ions. At low concentration (2.5 mol% of Eu2O3) and exciting within the high energy side of the inhomogeneous 7F0icons/Journals/Common/to" ALT="to" ALIGN="TOP"/> 5D0 absorption band, the luminescence spectrum mainly consists of a narrow resonant peak that repeats the exciting profile, indicating that the migration processes between Eu3+ ions within the 5D0 level is not important. However, at higher concentrations (5 to 11.5 mol% of Eu2O3) the luminescence spectrum contains not only a narrow emission but also a broad band due to ions excited by energy transfer (background fluorescence), which for long times well reproduces the inhomogeneous profile. The temporal evolution of the narrow band fluorescence and the shape of the background fluorescence have been analysed using a previously proposed model. The purpose is to understand the dynamics involved in the energy transfer processes caused by the interaction between Eu3+ ions and the implications in their luminescence. A very good agreement with the experimental results is found taking into account an energy dependent quadrupole-quadrupole (S = 10) non-radiative energy transfer process assisted by a phonon from Eu3+ ions at high crystal field sites to ions at low crystal field sites. The temperature dependence of the energy transfer processes is analysed in the range from 13 to 60 K.

  5. Studying CaSO4:Eu as an OSL phosphor

    NASA Astrophysics Data System (ADS)

    Guckan, Veysi; Altunal, Volkan; Nur, Necmettin; Depci, Tolga; Ozdemir, Adnan; Kurt, Kasim; Yu, Yan; Yegingil, Ihami; Yegingil, Zehra

    2017-09-01

    This study was carried out to investigate the properties of the OSL signal from Eu-doped calcium sulfate (CaSO4:Eu) phosphor and study on its thermal behavior as a function of temperature under a series of luminescence experiments. The suitability of its usage as an optically stimulated luminescence (OSL) dosimeter was also checked. CaSO4:Eu was synthesized using the precipitation method and prepared in pellet form. The dopant concentration value was performed as 0.1 mol%. The synthesized CaSO4:Eu was analyzed by X-ray diffraction (XRD) method to confirm the product. To have an idea about the crystallography and microstructure morphology of the material, scanning electron microscope (SEM) analysis were carried out. It was found that the OSL signal is a resultant signal having three components and exhibits thermal quenching above 150 °C. The excitation spectrum of CaSO4:Eu showed different peaks in the region 220-360 nm with the highest one at 269 nm. Thermoluminescence (TL) signals of CaSO4:Eu pellets were obtained and compared with the TL signals obtained after OSL measurements of the same pellets by blue light stimulation. The low temperature peak near 180 °C did not show any significant change in TL after OSL measurement whereas the high temperature peak at 240 °C was bleached with the blue light illumination and might be responsible for the observed OSL signal. The dosimetric properties such as dose response, minimum detectable dose, energy response, reusability, fading properties, thermal stability and effect of reading temperatures on OSL signals were examined. OSL signals of CaSO4:Eu pellets were decreased by approximately 8% at the end of the 24 h and by about 7% at the end of 28 days when compared with the first readout. The thermal stability of the ∼240 °C TL peak and OSL signal using isothermal decay measurements were used to determine the trap parameters. The CaSO4:Eu OSL dosimeter in accordance with the presented study allows a high

  6. The new EU healthcare rights directive: greater uniformity?

    PubMed

    McHale, Jean V

    On 9th March 2011 the new EU Directive on Patients' Rights in Cross-border Healthcare was adopted. This article explores its implications for the delivery of health care in the UK. It notes that the final version of the Directive provides much greater discretion to member states to control access to resources than was suggested in early drafts of the Directive. It explores the situations in which care can be subject to prior authorization and suggests that perhaps the greatest long-term impact of the Directive will not be in patient mobility as such but rather in relation to its impact on broader standard setting across the EU.

  7. The hydration properties of Eu(II) and Eu(III): An ab initio quantum mechanical molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Canaval, Lorenz R.; Rode, Bernd M.

    2015-01-01

    A comparison of the hydration characteristics of di- and trivalent europium ions in aqueous solution is presented. The established quantum mechanical charge-field molecular dynamics (QMCF-MD) approach yielded two 30 ps simulations. Significant differences among the two species were found in the Eu-O radial distribution functions, both in good agreement with experiments. The first shell coordination numbers of 8.1 and 8.9 were observed for Eu(II) and Eu(III), respectively. The mean residence time of first shell ligands differ by more than one order of magnitude, the divalent ion's hydration shell being more flexible, which is underlined by a weak ion-water bond strength.

  8. Luminescence of Eu ion in alumina prepared by plasma electrolytic oxidation

    NASA Astrophysics Data System (ADS)

    Smits, Krisjanis; Millers, Donats; Zolotarjovs, Aleksejs; Drunka, Reinis; Vanks, Martins

    2015-05-01

    Eu ion luminescence in aluminium oxide nanocrystals and layers prepared by plasma electrolytic oxidation (PEO) are investigated in this study. The Eu ion in PEO coatings has intense luminescence allowing such material to be used for preparation of various phosphor materials. In this study, Eu ion doped coatings were prepared with two methods: anodization and pulsed bipolar plasma electrolytic oxidation. Also, for comparative studies, alumina nanocrystals with the same amount of Eu ions were prepared using Sol Gel and molten salts methods. Obtained Eu-doped coatings were studied using luminescence methods. Typical Eu ion luminescence bands were observed, however intensity and spectral distribution differs drastically depending on preparation method and parameters used, therefore the Eu ion luminescence could be used as coating quality luminescent probe. Additionally, the possibility to incorporate the Eu ions in trivalent or divalent state exhibiting bright red and blue luminescence accordingly was demonstrated by using different oxidation parameters. Moreover, comparison measurements between powder samples and coatings were made.

  9. Detection of In segregation in InGaN by using Eu as a probe

    NASA Astrophysics Data System (ADS)

    Takatsu, Junichi; Mitchell, Brandon; Koizumi, Atsushi; Yamanaka, Shuhei; Matsuda, Masaaki; Gregorkiewicz, Tom; Kojima, Takanori; Fujiwara, Yasufumi

    2017-06-01

    Eu ions were doped into InGaN by organometallic vapor phase epitaxy. The influence of In composition on the optical properties of Eu-doped InGaN (InGaN:Eu) was investigated using photoluminescence (PL), and combined excitation-emission spectroscopy (CEES). The PL spectra of InGaN:Eu showed a new series of emission lines, which became dominant with increasing In content. CEES measurements confirmed that these emission lines originated from a new Eu luminescent center, with In as a second nearest neighbor. Thus, it is possible to distinguish the typical Eu-N related luminescent sites from the new Eu-N-In related luminescent site. Based upon our findings, we propose that Eu3+ ions doped in InGaN could be used as a microscopic probe for the detection of In segregation.

  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.; hide

    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. Tunable luminescence and enhanced photocatalytic activity for Eu(III) doped Bi2WO6 nanoparticles

    NASA Astrophysics Data System (ADS)

    Gu, Haidong; Yu, Lei; Wang, Juan; Ni, Min; Liu, Tingting; Chen, Feng

    2017-04-01

    A series of Eu(III) doped Bi2WO6 nanoparticles were synthesized by a hydrothermal process. The obtained Bi2WO6:Eu(III) nanoparticles were characterized by XRD, SEM, luminescence spectrophotometer and DRS. The XRD and TEM results indicate that the Eu(III) doping concentration has no influence on the phase and morphology. However, the Eu(III) doping can tune the luminescence and enhance the photocatalytic activity of Bi2WO6. With the increases of Eu3 + doping concentrations, the emission intensity of WO66 - group decreases nut the photocatalytic activity increases. The tunable luminescence of Bi2WO6:Eu(III) nanoparticles results from the energy transfer from WO66 - group to Eu(III) ion. The enhanced performance can be ascribed to efficient separation of electron and hole pairs after doping Eu(III) into the Bi2WO6 lattice.

  12. Tunable luminescence and enhanced photocatalytic activity for Eu(III) doped Bi2WO6 nanoparticles.

    PubMed

    Gu, Haidong; Yu, Lei; Wang, Juan; Ni, Min; Liu, Tingting; Chen, Feng

    2017-04-15

    A series of Eu(III) doped Bi2WO6 nanoparticles were synthesized by a hydrothermal process. The obtained Bi2WO6:Eu(III) nanoparticles were characterized by XRD, SEM, luminescence spectrophotometer and DRS. The XRD and TEM results indicate that the Eu(III) doping concentration has no influence on the phase and morphology. However, the Eu(III) doping can tune the luminescence and enhance the photocatalytic activity of Bi2WO6. With the increases of Eu(3+) doping concentrations, the emission intensity of WO6(6-) group decreases nut the photocatalytic activity increases. The tunable luminescence of Bi2WO6:Eu(III) nanoparticles results from the energy transfer from WO6(6-) group to Eu(III) ion. The enhanced performance can be ascribed to efficient separation of electron and hole pairs after doping Eu(III) into the Bi2WO6 lattice.

  13. 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.

  14. Electrochemiluminescence behaviors of Eu3+-doped CdS nanocrystals film in aqueous solution

    NASA Astrophysics Data System (ADS)

    Deng, Li; Shan, Yun; Xu, Jing-Juan; Chen, Hong-Yuan

    2012-01-01

    Eu3+ doped CdS nanocrystals (CdS:Eu NCs) were synthesized via a co-precipitation method. The doping of Eu3+ ions caused a 4-fold enhancement in electrochemiluminescence (ECL) intensity and more stable cathodic signals compared to pure CdS NCs. Such enhancement was mostly ascribed to doping-induced improvement in the stability of reduced NCs. A new emission peak around 620 nm was observed in ECL spectra of the doped NCs, which belongeded to the 5D0 --> 7F2 transition of Eu3+ ions in CdS NCs. Correspondingly, a pair of oxidation and reduction peaks occurred at +1.01 V and +0.61 V because of the formation of Eu3+-surface states complex when the CdS:Eu NCs solution underwent cyclic voltammogram scanning. Benefiting from the strong ECL emission of the doped NCs and high affinity of the doped Eu3+ ions to oxygen, the CdS:Eu NCs film showed a great oxygen-sensitivity. The intense red luminescence of the characteristic transitions of Eu3+ in CdS:Eu NCs would also have enormous potential in bioanlytical systems.Eu3+ doped CdS nanocrystals (CdS:Eu NCs) were synthesized via a co-precipitation method. The doping of Eu3+ ions caused a 4-fold enhancement in electrochemiluminescence (ECL) intensity and more stable cathodic signals compared to pure CdS NCs. Such enhancement was mostly ascribed to doping-induced improvement in the stability of reduced NCs. A new emission peak around 620 nm was observed in ECL spectra of the doped NCs, which belongeded to the 5D0 --> 7F2 transition of Eu3+ ions in CdS NCs. Correspondingly, a pair of oxidation and reduction peaks occurred at +1.01 V and +0.61 V because of the formation of Eu3+-surface states complex when the CdS:Eu NCs solution underwent cyclic voltammogram scanning. Benefiting from the strong ECL emission of the doped NCs and high affinity of the doped Eu3+ ions to oxygen, the CdS:Eu NCs film showed a great oxygen-sensitivity. The intense red luminescence of the characteristic transitions of Eu3+ in CdS:Eu NCs would also have

  15. 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…

  16. Evaluating U.S. and EU Trans Sahel Policies

    DTIC Science & Technology

    2013-03-01

    Evaluating U.S. and EU Trans Sahel Policies by Lieutenant Colonel Abdelkarim Aboulghit Royal Moroccan Army...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Lieutenant Colonel Abdelkarim Aboulghit Royal Moroccan ...SUPPLEMENTARY NOTES Word Count: 6,019 14. ABSTRACT The importance of Africa has increased significantly over the last decade, for a variety of

  17. EuPathDB: the eukaryotic pathogen genomics database resource

    PubMed Central

    Aurrecoechea, Cristina; Barreto, Ana; Basenko, Evelina Y.; Brestelli, John; Brunk, Brian P.; Cade, Shon; Crouch, Kathryn; Doherty, Ryan; Falke, Dave; Fischer, Steve; Gajria, Bindu; Harb, Omar S.; Heiges, Mark; Hertz-Fowler, Christiane; Hu, Sufen; Iodice, John; Kissinger, Jessica C.; Lawrence, Cris; Li, Wei; Pinney, Deborah F.; Pulman, Jane A.; Roos, David S.; Shanmugasundram, Achchuthan; Silva-Franco, Fatima; Steinbiss, Sascha; Stoeckert, Christian J.; Spruill, Drew; Wang, Haiming; Warrenfeltz, Susanne; Zheng, Jie

    2017-01-01

    The Eukaryotic Pathogen Genomics Database Resource (EuPathDB, http://eupathdb.org) is a collection of databases covering 170+ eukaryotic pathogens (protists & fungi), along with relevant free-living and non-pathogenic species, and select pathogen hosts. To facilitate the discovery of meaningful biological relationships, the databases couple preconfigured searches with visualization and analysis tools for comprehensive data mining via intuitive graphical interfaces and APIs. All data are analyzed with the same workflows, including creation of gene orthology profiles, so data are easily compared across data sets, data types and organisms. EuPathDB is updated with numerous new analysis tools, features, data sets and data types. New tools include GO, metabolic pathway and word enrichment analyses plus an online workspace for analysis of personal, non-public, large-scale data. Expanded data content is mostly genomic and functional genomic data while new data types include protein microarray, metabolic pathways, compounds, quantitative proteomics, copy number variation, and polysomal transcriptomics. New features include consistent categorization of searches, data sets and genome browser tracks; redesigned gene pages; effective integration of alternative transcripts; and a EuPathDB Galaxy instance for private analyses of a user's data. Forthcoming upgrades include user workspaces for private integration of data with existing EuPathDB data and improved integration and presentation of host–pathogen interactions. PMID:27903906

  18. Brexit is not only factor in EU nurse downturn.

    PubMed

    Buchan, James

    2017-03-08

    Headlines have been screaming about European nurses 'giving up on the NHS'. This was triggered when the Nursing and Midwifery Council (NMC) reported that the number of EU nurses registering to work in the UK was down more than 90% since the Brexit vote in June last year.

  19. 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…

  20. 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…

  1. 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.

  2. EU firms bump up R&D spend

    NASA Astrophysics Data System (ADS)

    Allen, Michael

    2017-01-01

    Companies in the European Union increased their spending on research and development (R&D) in the 2015/16 financial year at a higher rate than the global average, according to the latest EU Industrial R&D Investment Scoreboard.

  3. Challenges in Evaluating the EU's Lifelong Learning Policies

    ERIC Educational Resources Information Center

    Clain, Alexandru

    2016-01-01

    Since the early 1990s, lifelong learning has become a major policy concern for the European Union, being seen as a means for enabling individuals to be more competitive in social and economic contexts that are continually changing. After a series of white papers and strategies in the field of lifelong learning, the EU launched the Lifelong…

  4. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. 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.

  6. Challenges in Evaluating the EU's Lifelong Learning Policies

    ERIC Educational Resources Information Center

    Clain, Alexandru

    2016-01-01

    Since the early 1990s, lifelong learning has become a major policy concern for the European Union, being seen as a means for enabling individuals to be more competitive in social and economic contexts that are continually changing. After a series of white papers and strategies in the field of lifelong learning, the EU launched the Lifelong…

  7. 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)

  8. 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…

  9. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Weed biocontrol in the EU: from serendipity to strategy

    USDA-ARS?s Scientific Manuscript database

    Biological control of weeds is a globally-recognized approach to the management of the worst invasive plants in the world. Unfortunately, accidental introduction of agents account for most weed biocontrol in the EU, but do include a number of current or emerging successes. From the redistribution of...

  11. 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…

  12. EuPathDB: the eukaryotic pathogen genomics database resource.

    PubMed

    Aurrecoechea, Cristina; Barreto, Ana; Basenko, Evelina Y; Brestelli, John; Brunk, Brian P; Cade, Shon; Crouch, Kathryn; Doherty, Ryan; Falke, Dave; Fischer, Steve; Gajria, Bindu; Harb, Omar S; Heiges, Mark; Hertz-Fowler, Christiane; Hu, Sufen; Iodice, John; Kissinger, Jessica C; Lawrence, Cris; Li, Wei; Pinney, Deborah F; Pulman, Jane A; Roos, David S; Shanmugasundram, Achchuthan; Silva-Franco, Fatima; Steinbiss, Sascha; Stoeckert, Christian J; Spruill, Drew; Wang, Haiming; Warrenfeltz, Susanne; Zheng, Jie

    2017-01-04

    The Eukaryotic Pathogen Genomics Database Resource (EuPathDB, http://eupathdb.org) is a collection of databases covering 170+ eukaryotic pathogens (protists & fungi), along with relevant free-living and non-pathogenic species, and select pathogen hosts. To facilitate the discovery of meaningful biological relationships, the databases couple preconfigured searches with visualization and analysis tools for comprehensive data mining via intuitive graphical interfaces and APIs. All data are analyzed with the same workflows, including creation of gene orthology profiles, so data are easily compared across data sets, data types and organisms. EuPathDB is updated with numerous new analysis tools, features, data sets and data types. New tools include GO, metabolic pathway and word enrichment analyses plus an online workspace for analysis of personal, non-public, large-scale data. Expanded data content is mostly genomic and functional genomic data while new data types include protein microarray, metabolic pathways, compounds, quantitative proteomics, copy number variation, and polysomal transcriptomics. New features include consistent categorization of searches, data sets and genome browser tracks; redesigned gene pages; effective integration of alternative transcripts; and a EuPathDB Galaxy instance for private analyses of a user's data. Forthcoming upgrades include user workspaces for private integration of data with existing EuPathDB data and improved integration and presentation of host-pathogen interactions.

  13. The EU Emissions Trading Scheme: A Challenge to U.S. Sovereignty

    DTIC Science & Technology

    2012-02-07

    the U.S. Government to oppose: taxes , the EU, and the environment. Additionally, there are many in the EU Parliament who think the airlines got a... environmental policy, and international law. 15. SUBJECT TERMS Aviation, cap-and-trade, climate change 16. SECURITY CLASSIFICATION OF: 17...over sovereignty issues, EU environmental policy, and international law. THE EU EMISSIONS TRADING SCHEME: A CHALLENGE TO U.S. SOVEREIGNTY

  14. 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.

  15. 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

  16. 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…

  17. 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…

  18. 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.

  19. HR4EU--A Web-Portal for E-Learning of Croatian

    ERIC Educational Resources Information Center

    Filko, Matea; Farkaš, Daša; Hriberski, Diana

    2016-01-01

    In this paper, we present the HR4EU--a web portal for e-learning of Croatian. HR4EU is the first portal that offers Croatian language courses which are free-of-charge and developed by language professionals. Moreover, HR4EU also integrates bidirectional interaction with some of the previously developed language resources for Croatian. The HR4EU…

  20. 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…

  1. Hyper-stable organo-Eu(III) luminophore under high temperature for photo-industrial application.

    PubMed

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

    2016-04-14

    Novel organo-Eu(III) 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 Eu(III) 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 Eu(III) 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.

  2. 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…

  3. 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 from…

  4. 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 from…

  5. 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.

  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. The EU-ADR Web Platform: delivering advanced pharmacovigilance tools.

    PubMed

    Oliveira, José Luis; Lopes, Pedro; Nunes, Tiago; Campos, David; Boyer, Scott; Ahlberg, Ernst; van Mulligen, Erik M; Kors, Jan A; Singh, Bharat; Furlong, Laura I; Sanz, Ferran; Bauer-Mehren, Anna; Carrascosa, Maria C; Mestres, Jordi; Avillach, Paul; Diallo, Gayo; Díaz Acedo, Carlos; van der Lei, Johan

    2013-05-01

    Pharmacovigilance methods have advanced greatly during the last decades, making post-market drug assessment an essential drug evaluation component. These methods mainly rely on the use of spontaneous reporting systems and health information databases to collect expertise from huge amounts of real-world reports. The EU-ADR Web Platform was built to further facilitate accessing, monitoring and exploring these data, enabling an in-depth analysis of adverse drug reactions risks. The EU-ADR Web Platform exploits the wealth of data collected within a large-scale European initiative, the EU-ADR project. Millions of electronic health records, provided by national health agencies, are mined for specific drug events, which are correlated with literature, protein and pathway data, resulting in a rich drug-event dataset. Next, advanced distributed computing methods are tailored to coordinate the execution of data-mining and statistical analysis tasks. This permits obtaining a ranked drug-event list, removing spurious entries and highlighting relationships with high risk potential. The EU-ADR Web Platform is an open workspace for the integrated analysis of pharmacovigilance datasets. Using this software, researchers can access a variety of tools provided by distinct partners in a single centralized environment. Besides performing standalone drug-event assessments, they can also control the pipeline for an improved batch analysis of custom datasets. Drug-event pairs can be substantiated and statistically analysed within the platform's innovative working environment. A pioneering workspace that helps in explaining the biological path of adverse drug reactions was developed within the EU-ADR project consortium. This tool, targeted at the pharmacovigilance community, is available online at https://bioinformatics.ua.pt/euadr/. Copyright © 2012 John Wiley & Sons, Ltd.

  8. 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.

  9. High pressure and time-resolved luminescence spectra of Ca3Y2(SiO4)3 doped with Eu2+ and Eu3+.

    PubMed

    Baran, A; Mahlik, S; Grinberg, M; Zych, E

    2013-01-16

    Tricalcium diyttrium trisilicon oxide, Ca(3)Y(2)(SiO(4))(3) doped with Eu(2+) and Eu(3+) belongs to a very limited number of hosts able to accommodate both Eu(3+) and Eu(2+) ions, which might make it useful for white light emitting diodes (WLEDs) based on UV chip technology. In this contribution we present a detailed study of photoluminescence kinetics and high pressure spectroscopy of Eu(3+) and Eu(2+) doped Ca(3)Y(2)(SiO(4))(3). At ambient pressure and room temperature, under excitation with near-UV radiation, a broad emission band from 400 to 550 nm due to the 4f(6)5d(1)→4f(7)((8)S(7/2)) transition in Eu(2+) was observed, as well as several emission peaks in the region between 550 and 710 nm, ascribed to the (5)D(0)→ (7)F(J) (J = 0-4) transitions in Eu(3+). The bluish green luminescence related to Eu(2+) in the Ca(3)Y(2)(SiO(4))(3) exhibits a small red pressure-induced shift reaching -5.2 cm(-1)/kbar. The red shifts of the luminescence lines related to Eu(3+) ion emission vary from 0.15 to -0.54 cm(-1)/kbar. Time-resolved photoluminescence was measured at different temperatures and pressures. Luminescence decay traces were studied for the bluish green emission band of Eu(2+) and for the red emission peak due to the (5)D(0) →  (7)F(2) transition of Eu(3+). Decay times slightly decreased with increasing pressure.

  10. 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.

  11. 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.

  12. 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}.

  13. Thermally and optically stimulated luminescence in long persistent orthorhombic strontium aluminates doped with Eu, Dy and Eu, Nd

    NASA Astrophysics Data System (ADS)

    Zúñiga-Rivera, N. J.; Salas-Castillo, P.; Chernov, V.; Díaz-Torres, L. A.; Meléndrez, R.; García-Gutierrez, R.; Carrillo-Torres, R. C.; Barboza-Flores, M.

    2017-05-01

    The long persistent luminescence, thermoluminescence (TL) and IR stimulated luminescence properties of two orthorhombic strontium aluminates (Sr4Al14O25) co-doped with Eu2+, Dy3+ and Eu2+, Nd3+ exposed to beta radiation is reported. The phosphors were synthesized by the combustion method followed by a post-annealing treatment under a reductive carbon atmosphere. Photoluminescence emission spectra of both phosphors are typical for emission of Eu2+ ions with 7-fold and 10-fold coordination in Sr4Al14025 and consist of the main band at 480 nm and a weak band between 390 and 440 nm. After exposure to beta radiation the Sr4Al14025:Eu2+,Dy3+ phosphor exhibits two strongly overlapped TL peaks at about 70 and 100 °C while the low temperature TL of the Sr4Al14025:Eu2+,Nd3+ phosphor consist of two well separated peaks with maxima at about 60 and 130 °C. Additionally, both phosphors exhibit a weak TL between 180 and 400 °C. The traps responsible for the low temperature TL peaks are the Dy3+ and Nd3+ centers situated in two different Sr sites with 7-fold and 10-fold coordination. The thermal emptying of the Dy and Nd filled traps creates ultra-long intense afterglow, which gradually decays with time and remains detectable after 220 h storage in dark. IR stimulation of beta irradiated phosphors creates intense IR stimulated luminescence, which is related to the release of electrons from the filled Dy and Nd traps.

  14. Unique phase diagram with narrow superconducting dome in EuFe2(As1-xPx)2 due to Eu2+ local magnetic moments

    NASA Astrophysics Data System (ADS)

    Tokiwa, Y.; Hübner, S.-H.; Beck, O.; Jeevan, H. S.; Gegenwart, P.

    2012-12-01

    The interplay between superconductivity and Eu2+ magnetic moments in EuFe2(As1-xPx)2 is studied with electrical resistivity measurements under hydrostatic pressure on x=0.13 and x=0.18 single crystals. We can map hydrostatic pressure to chemical pressure x and show that superconductivity is confined to a very narrow range 0.18≤x≤0.23 in the phase diagram, beyond which ferromagnetic (FM) Eu ordering suppresses superconductivity. The change from antiferro- to FM Eu ordering at the latter concentration coincides with a Lifshitz transition and the complete depression of iron magnetic order.

  15. Evolution of Eu valence and superconductivity in layered Eu0.5La0.5FBiS2 -xSex system

    NASA Astrophysics Data System (ADS)

    Mizuguchi, Y.; Paris, E.; Wakita, T.; Jinno, G.; Puri, A.; Terashima, K.; Joseph, B.; Miura, O.; Yokoya, T.; Saini, N. L.

    2017-02-01

    We have studied the effect of Se substitution on Eu valence in a layered Eu0.5La0.5FBiS2 -xSex superconductor using a combined analysis of x-ray absorption near-edge structure (XANES) and x-ray photoelectron spectroscopy (XPS) measurements. Eu L3-edge XANES spectra reveal that Eu is in the mixed valence state with coexisting Eu2 + and Eu3 +. The average Eu valence decreases sharply from ˜2.3 for x =0.0 to ˜2.1 for x =0.4 . Consistently, Eu 3 d XPS shows a clear decrease in the average valence by Se substitution. Bi 4 f XPS indicates that effective charge carriers in the BiCh2 (Ch = S, Se) layers are slightly increased by Se substitution. On the basis of the present results it has been discussed that the metallic character induced by Se substitution in Eu0.5La0.5FBiS2 -xSex is likely to be due to increased in-plane orbital overlap driven by reduced in-plane disorder that affects the carrier mobility.

  16. 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.

  17. Multimodal luminescence properties of surface-treated ZnSe quantum dots by Eu

    NASA Astrophysics Data System (ADS)

    Park, Ji Young; Jeong, Da-Woon; Lim, Kyoung-Mook; Choa, Yong-Ho; Kim, Woo-Byoung; Kim, Bum Sung

    2017-09-01

    ZnSe:Eu quantum dots (QDs) were synthesized using the heating-up method by adding a Eu precursor in Zn and Se precursors. The optical property was investigated based on the change in the multimodal emission caused by increasing the amount of the Eu precursor. The emission wavelength of ZnSe QDs increased from 398 nm to 405 nm when the reaction was carried out for 30-300 s. The broad spectrum was attributed to the 4F65D1 → 4F7 transition when the Eu2+ emission was increased from 450 to 550 nm. Eu3+ shows characteristic red emission peaks at 579, 592, 615, 651, and 700 nm owing to the electronic transition of 5D0 → 7Fj (j = 0, 1, 2, 3, 4). The expected structure of the ZnSe:Eu QDs was verified by XRD, TEM, and XPS. Compared to the diffraction peaks of pristine ZnSe, the corresponding peaks for the ZnSe:Eu QDs are shifted, by about 0.43°, to larger angles, because the ionic radius of Eu3+ (0.95 Å) is larger than that of Zn2+ (0.74 Å). They also have Eu2+sbnd O and Eu3+sbnd O dangling bonds on the surface of Eu3+-doped ZnSe QDs, with an average size of about 3.15 nm. These semiconductor QDs with rare earth elements are promising candidates to fabricate light-converting materials.

  18. 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.

  19. 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.

  20. 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.

  1. Synthesis and Optical Properties of Eu3+ Doped CdS Nanostructures

    NASA Astrophysics Data System (ADS)

    Saravanan, L.; Pandurangan, A.; Jayavel, R.

    2010-10-01

    Eu3+ doped cadmium sulphide (Cd0.98Eu0.2S) nanostructures were synthesised by chemical co-precipitation method using isopropyl alcohol (IPA): DI water and ethylene glycol (EG): DI water as mixed solvents. Powder XRD reveals the formation of hexagonal (wurtzite) and cubic (zinc blende) phase of Eu:CdS with different solvents. From the SEM micrographs the formation of flower and paddy like structures of Eu3+ doped CdS was observed. The stoichiometric chemical composition of the samples was studied using ICP analysis. Band gap values of Eu:CdS nanocrystals synthesized from different solvents were estimated using UV-reflectance spectra. The presence of Eu3+ ion shows significant changes in the PL emission of the CdS nanocrystals. It was observed that the shift in the emission and efficiency of Eu:CdS depends on size and shapes of the synthesised nanoparticles.

  2. 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.

  3. 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.

  4. 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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Cofluorescence of Eu 3+ in complexes of aromatic carboxylic acids

    NASA Astrophysics Data System (ADS)

    Panigrahi, B. S.; Peter, Susy; Viswanathan, K. S.

    1997-12-01

    The fluorescence of Eu 3+ in certain Eu 3+-aromatic acid complexes were enhanced by over two orders of magnitude, by the addition of La 3+; a process referred to as cofluorescence. Cofluorescence was observed only with certain aromatic acid ligands; trismesic acid, pyromellitic acid and mellitic acid; thereby clearly establishing a correlation between the structure of the ligand and the process of cofluorescence. While cofluorescence has been extensively studied using β-diketones as ligands, our studies demonstrate cofluorescence for the first time in ligands other than β-diketones. Furthermore, the mechanism of cofluorescence in the aromatic acid complexes studied by us appears to be different from that operating in the β-diketones. While intermolecular energy transfer is believed to occur in the β-diketones, formation of polynuclear complexes appears to be responsible for cofluorescence in the aromatic acid ligands.

  6. 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.

  7. 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.

  8. Disintegration rate measurement of a 152Eu solution.

    PubMed

    Koskinas, Marina F; Fonseca, Kátia A; Dias, Mauro S

    2002-01-01

    The procedure followed by the Laboratório de Metrologia Nuclear at the IPEN-CNEN/SP, in São Paulo, for the standardization of 152Eu is described. The disintegration rate of 152Eu has been measured using the 4pi beta-gamma coincidence technique, using a 4pi proportional counter, filled with P-10 gas and operated at 0.1 MPa, coupled to one HPGe detector for the gamma-ray emission. Two discrimination windows were set in the gamma-channel, one related to the beta branch (344 keV) and the other related to the electron capture events (1408.03 keV), in order to determine the counting efficiencies for beta, X-ray and Auger electron events in the proportional counter. The activity of solution was determined by a biparametric extrapolation curve obtained for the two selected gamma-windows.

  9. Phase diagram of Eu magnetic ordering in Sn-flux-grown Eu (Fe1-xCox) 2As2 single crystals

    NASA Astrophysics Data System (ADS)

    Jin, W. T.; Xiao, Y.; Bukowski, Z.; Su, Y.; Nandi, S.; Sazonov, A. P.; Meven, M.; Zaharko, O.; Demirdis, S.; Nemkovski, K.; Schmalzl, K.; Tran, Lan Maria; Guguchia, Z.; Feng, E.; Fu, Z.; Brückel, Th.

    2016-11-01

    The magnetic ground state of the Eu2 + moments in a series of Eu (Fe1-xCox) 2As2 single crystals grown from the Sn flux has been investigated in detail by neutron diffraction measurements. Combined with the results from the macroscopic properties (resistivity, magnetic susceptibility and specific heat) measurements, a phase diagram describing how the Eu magnetic order evolves with Co doping in Eu (Fe1-xCox) 2As2 is established. The ground-state magnetic structure of the Eu2 + spins is found to develop from the A-type antiferromagnetic (AFM) order in the parent compound, via the A-type canted AFM structure with some net ferromagnetic (FM) moment component along the crystallographic c direction at intermediate Co doping levels, finally to the pure FM order at relatively high Co doping levels. The ordering temperature of Eu declines linearly at first, reaches the minimum value of 16.5(2) K around x =0.100 (4 ) , and then reverses upwards with further Co doping. The doping-induced modification of the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu2 + moments, which is mediated by the conduction d electrons on the (Fe,Co)As layers, as well as the change of the strength of the direct interaction between the Eu2 + and Fe2 + moments, might be responsible for the change of the magnetic ground state and the ordering temperature of the Eu sublattice. In addition, for Eu (Fe1-xCox) 2As2 single crystals with 0.10 ≤x ≤ 0.18 , strong ferromagnetism from the Eu sublattice is well developed in the superconducting state, where a spontaneous vortex state is expected to account for the compromise between the two competing phenomena.

  10. Switching photoluminescence channels between dopant Eu2+ and Eu3+ ions in ZnO thin films by varying the post-annealing conditions

    NASA Astrophysics Data System (ADS)

    Akazawa, Housei; Shinojima, Hiroyuki

    2016-09-01

    An Eu-doped ZnO (ZnO:Eu) is an extensively investigated optical material. While most studies reported photoluminescence (PL) from Eu3+ ions resulting from the electronic transitions between 4f levels (5D0→7FJ), the evidence of emissions from Eu2+ ions remains limited. Here, we report that a violet emission in the wavelength region between 450 and 500 nm emerged from the sputter-deposited ZnO:Eu films that were post-annealed at 900 °C in an O2 ambient. This emission peak was away from the band edge and the defect green emissions of ZnO, and it was identified as being from Eu2+ ions. Simultaneous emergence of the red emission bands at wavelengths longer than 600 nm indicated that Zn vacancies (VZn) were created during a high-temperature annealing and that producing VZn promoted substitution at Zn2+ sites with Eu2+ ions. In contrast, when annealing was done in a vacuum, the defect emissions were attenuated and the PL spectra showed only band-edge emissions. Here, it can be interpreted that this reduced state, where some oxygen atoms have been removed from the ZnO lattice, has a short lifetime of excitons. In contrast, loading hydrogen atoms into the a ZnO lattice by annealing in an H2 ambient at 350 °C generated a weak Eu3+ emission at 612 nm along with an orange emission band ranging from 550 to 650 nm, which was from the OH termination at the surfaces and interfaces of the ZnO crystals. In this system, a codoping of H+ with Eu3+ ions assists the substitution at Zn2+ sites through a charge compensation. The present results, thus, demonstrate that the emergence of Eu2+ and Eu3+ emissions can be simply controlled by selecting the annealing conditions.

  11. Characterization of various Eu2+ sites in Ca2SiO4:Eu2+ and Ba2SiO4:Eu2+ by high-pressure spectroscopy

    NASA Astrophysics Data System (ADS)

    Grinberg, M.; Barzowska, J.; Baran, A.; Kukliński, B.

    2011-12-01

    Photoluminescence of Ba2SiO4 and Ca2SiO4 activated with Eu2+ was investigated at various temperatures (from 10 K to 300 K) and pressures (from ambient to 200 kbar). At ambient pressure and room temperature, under UV excitation both phosphors yielded a green emission band with maxima at 505 nm and 510 nm for Ba2SiO4 and Ca2SiO4, respectively. The energies of these bands depended on pressure; the pressure shifts were -12:55 cm-1/kbar for Ba2SiO4:Eu2+; and -5:59 cm-1/kbar for Ca2SiO4:Eu2+. In the case of Ca2SiO4:Eu2+, we observed additional broadband emission at lower energies with a maximum at 610 nm (orange band). The orange and green emission in Ca2SiO4:Eu2+ had different excitation spectra: the green band could be excited at wavelengths shorter than 470 nm, whereas the orange band — at wavelengths shorter than 520 nm. The pressure caused a red shift of orange emission of 7.83 cm-1/kbar. The emission peaked at 510 nm was attributed to the 4f65d→4f7(8S7=2) transition of Eu2+ in the β — Ca2SiO4:Eu2+ phase, whereas the emission peaked at 610 nm — to the γ — Ca2SiO4:Eu2+ phase. The emission of Ba2SiO4:Eu2+ peaked at 505 nm was attributed to the 4f65d→ 4f7(8S7/2) transition of Eu2+ in the β — Ba2SiO4 phase.

  12. Synthesis and photoluminescence properties of Eu3+-doped silica@coordination polymer core-shell structures and their calcinated silica@Gd2O3:Eu and hollow Gd2O3:Eu microsphere products.

    PubMed

    Lee, Hee Jung; Park, Ju-Un; Choi, Sora; Son, Juhee; Oh, Moonhyun

    2013-02-25

    The conjugation of Eu(3+)-doped coordination polymers constructed from Gd(3+) and isophthalic acid (H(2)IPA) with silica particles is investigated for the production of luminescent microspheres. A series of doping ratio-controlled silica@coordination polymer core-shell spheres is easily synthesized by altering the amounts of metal nodes used in the reactions, where the ratios of Gd(3+) and Eu(3+) are 10:0 (1a), 9:1 (1b), 8:2 (1c), 7:3 (1d), 5:5 (1e), and 0:10 (1f). The formation of monodisperse uniform core-shell structures is achieved throughout the entirety of a series. Investigations of the photoluminescence property of the resulting series of silica@coordination polymer core-shell spheres reveal that 20% Eu(3+)-doped product (1c) has the strongest emission intensity. The subsequent calcination process on the silica@coordination polymer core-shell structures (1a-f) results in the formation of a series of doping ratio-controlled silica@Gd(2)O(3):Eu core-shell microspheres (2a-f) with uniform shell thickness. During the calcination step, the coordination polymers within silica@coordination polymer core-shells are transformed into metal oxides, resulting in silica@Gd(2)O(3):Eu core-shell structures. The final etching process on the silica@Gd(2)O(3):Eu core-shell microspheres (2a-f) produces a series of hollow Gd(2)O(3):Eu microspheres (3a-f) as a result of the elimination of silica cores. The luminescence intensities of silica@Gd(2)O(3):Eu core-shell (2a-f) and hollow Gd(2) O(3):Eu microspheres (3a-f) also vary depending upon the doping ratio of Eu(3+) ions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Correlation between Tc and Eu Lattice Vibration in T'-Phase Superconductor (La1-xEux)2-yCeyCuO4-δ Observed by 151Eu Mössbauer Effect

    NASA Astrophysics Data System (ADS)

    Itoh, Hideaki; Kusuhashi, Mikio; Taniwaki, Masafumi

    1990-09-01

    The electronic state and lattice vibration of Eu in T'-phase (La1-xEux)2-yCeyO4-δ was studied by 151Eu Mössbauer effect. The isomer shift and the Debye temperature of Eu, \\varThetaD, showed that Eu is trivalent, and the Eu-O distance is larger than those in the hole-doped superconductors. With increasing Eu concentration, in spite of the shortening of the lattice constants, \\varThetaD in T'-phase decreased. This is probably caused by the increase in the Eu-O distance with the change of Eu-O-La bonding into Eu-O-Eu bonding. A tight correlation between Tc and \\varThetaD was found and the relation, Tc{=}0.772\\varThetaD\\exp (-\\varThetaD2/13000), was derived.

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

    PubMed

    Farrel, Anne-Maree

    2009-03-01

    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.

  15. Luminescence of potassium sulphate crystals doped by Eu3+ ions

    NASA Astrophysics Data System (ADS)

    Koketai, T.; Tussupbekova, A.; Baltabekov, A.; Mussenova, E.

    2017-01-01

    This paper presents results of the study some spectral-luminescent properties of potassium sulphate crystals activated europium trivalent ions. The observed changes might be connected with the fact of crystals having Eu3+ ions and NO3 - impurity ions. There was a proposition of the possibility of selective creation of impurity centers with the help of using various salts is normal for all the transition metal ions.

  16. Efficient electroluminescence from new lanthanide (Eu3+, Sm3+) complexes.

    PubMed

    Yu, Jiangbo; Zhou, Liang; Zhang, Hongjie; Zheng, Youxuan; Li, Huanrong; Deng, Ruiping; Peng, Zeping; Li, Zhefeng

    2005-03-07

    The syntheses, structures, and electroluminescent properties are described for two new lanthanide complexes Ln(HFNH)3phen [HFNH = 4,4,5,5,6,6,6-heptafluoro-1-(2-naphthyl)hexane-1,3-dione; phen = 1,10-phenanthroline; Ln = Eu3+ (1), Sm3+ (2)]. Both complexes exhibit bright photoluminescence at room temperature (RT) due to the characteristic emission of Eu3+ and Sm3+ ion. Several devices using the two complexes as emitters were fabricated. The performances of these devices are among the best reported for devices using europium complex and samarium complex as emitters. The device based on 1 with the structure ITO/TPD (50 nm)/1:CBP (10%, 40 nm)/BCP (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (200 nm) exhibits the maximum brightness of 957 cd/m2, current efficiency of 4.14 cd/A, and power efficiency of 2.28 lm/W with a pure red Eu3+ ion emission. Especially, at the high brightness of 200 cd/m2, the device of 1 still has a high current efficiency of 2.15 cd/A. The device of 2 with a three-layer structure of ITO/TPD (50 nm)/2 (50 nm)/BCP (20 nm)/LiF (1 nm)/Al (200 nm) gives the maximum brightness of 42 cd/m2, current efficiency of 0.18 cd/A. By the comparison of the electroluminescent properties of devices based on Eu(TTA3phen (TTA = 2-thenoyltrifluoroacteonate) and 1, we conclude that the polyfluoration on the alkyl group of the ligand and the introduction of the long conjugate naphthyl group into the ligand improve the efficiency of 1-doped devices, especially at high current densities.

  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. An overview of EU and USA intestinal transplant current activity.

    PubMed

    Lauro, A; Panaro, F; Iyer, K R

    2017-04-01

    To report the current activity of intestinal transplantation in Europe (EU) and Unites States of America (USA), underlining outcomes in the last 5 years and discussing possible trends. Data review of results was performed through analysis of ITR and UNOS registries, Eurotransplant and newsletter transplant reports, congress abstracts, international published literature, personal communications and hospital web sites. The absence in Europe of a sole organization collecting donors and the presence of many low-volume centers (less than 5 cases/year) makes the difference with USA: in the last 5 years (2010-2014), 222 intestinal/multivisceral transplants have been performed in EU countries (most of them in the UK), while in USA, the number of transplants achieved 634 procedures in the same period of time. Waiting list mortality remains unacceptable in both continents. Improved short-term results, with over 80% survival at 1 year, have been achieved in the busiest transplant centers likely due to immune-induction agents, more recently to innovative cross match strategies and optimizing organ allocation, but long term outcomes are still inferior to other organ transplants. Most long-term survivors were reintegrated to society with self-sustained socioeconomic status. The economic burden for the society is high and related costs are different between USA and EU (and inside Europe between member state's health-care systems), but cost-effectiveness for intestinal transplantation still needs to be proved. Overall intestinal transplantation continues to develop in EU and USA together with surgical and medical rehabilitation of patients affected by short gut syndrome. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. 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.

  20. Ukraine: Implications of Future Cooperation with the EU and NATO

    DTIC Science & Technology

    2013-03-01

    European Neighbourhood Policy (ENP) coincided with the Orange Revolution in Ukraine. This conjunction of events accounted for what has amounted to a...Today, such basic priorities as Ukraine’s foreign policy as non-block status, the active participation in development of a European system of collective...opportunities lack a sufficient cohesion of security policies between the EU and Ukraine, which can have an adverse effect on European , including

  1. GTSnext and Earthtime-EU a progress report

    NASA Astrophysics Data System (ADS)

    Wijbrans, J. R.; Pälike, H.; Kuiper, K.; Hilgen, F.; Gtsnext; Earthtime-Eu

    2010-12-01

    EARTHTIME started as a science driven initiative sponsored in the period 2003- 2009 through the NSF. The main aim was to provide a multi-disciplinary, global platform for researchers of the Geological Timescale, with the objective to transcend traditional limitations of a mono-disciplinary approach. The European contribution to EARTHTIME includes: an ESF sponsored Exploratory Workshop (2007), an EU FP7 Initial Training Network ‘GTSnext’ (2008- 2012), and an ESF-sponsored Research Network Platform (2010 - 2015), and an ambition further develop the Earthtime concept on a global level by stimulating the interaction between ESF and NSF. GTSnext has now passed its midterm review, and is entering the phase where projects should start yielding new data: 1. on the three time slices that form the focus of GTSnext: Neogene, Paleogene, and Cretaceous, and 2. on technical developments. Technical developments include improved capabilities for U-Pb dating of zircons, now allowing the analysis of small zircon fragments that crystallized upon eruption, thus by-passing the residence time problem, and the development of a protocol for a ‘first principles’ calibration of a mineral standard for 40Ar/39Ar dating. Earthtime-EU is now planning a kick-off meeting in Barcelona, Spain, in February 2011 with the objective to involve the science community in setting the agenda for Earthtime-EU in terms of workshop topic proposals. The main contributions of Earthtime-EU will be in thematic workshops, such as the next Earthtime isotope geochronology workshop in 2012.

  2. Incorporating potency into EU classification for carcinogenicity and reproductive toxicity.

    PubMed

    Hennes, C; Batke, M; Bomann, W; Duhayon, S; Kosemund, K; Politano, V; Stinchcombe, S; Doe, J

    2014-11-01

    Although risk assessment, assessing the potential harm of each particular exposure of a substance, is desirable, it is not feasible in many situations. Risk assessment uses a process of hazard identification, hazard characterisation, and exposure assessment as its components. In the absence of risk assessment, the purpose of classification is to give broad guidance (through the label) on the suitability of a chemical in a range of use situations. Hazard classification in the EU is a process involving identification of the hazards of a substance, followed by comparison of those hazards (including degree of hazard) with defined criteria. Classification should therefore give guidance on degree of hazard as well as hazard identification. Potency is the most important indicator of degree of hazard and should therefore be included in classification. This is done for acute lethality and general toxicity by classifying on dose required to cause the effect. The classification in the EU for carcinogenicity and reproductive toxicity does not discriminate across the wide range of potencies seen (6 orders of magnitude) for carcinogenicity and for developmental toxicity and fertility. Therefore potency should be included in the classification process. The methodology in the EU guidelines for classification for deriving specific concentration limits is a rigorous process for assigning substances which cause tumours or developmental toxicity and infertility in experimental animals to high, medium or low degree of hazard categories by incorporating potency. Methods are suggested on how the degree of hazard so derived could be used in the EU classification process to improve hazard communication and in downstream risk management.

  3. Intrinsic radioactivity of KSr2I5:Eu2+

    NASA Astrophysics Data System (ADS)

    Rust, M.; Melcher, C.; Lukosi, E.

    2016-10-01

    A current need in nuclear security is an economical, yet high energy resolution (near 2%), scintillation detector suitable for gamma-ray spectroscopy. For current scintillators on the market, there is an inverse relationship between scintillator energy resolution and cost of production. A new promising scintillator, KSr2I5:Eu2+, under development at the University of Tennessee, has achieved an energy resolution of 2.4% at 662 keV at room temperature, with potential growth rates exceeding several millimeters per hour. However, the internal background due to the 40K content could present a hurdle for effective source detection/identification in nuclear security applications. As a first step in addressing this question, this paper reports on a computational investigation of the intrinsic differential pulse height spectrum (DPHS) generated by 40K within the KSr2I5:Eu2+ scintillator as a function of crystal geometry. It was found that the DPHS remains relatively equal to a constant multiplicative factor of the negatron emission spectrum with a direct increase of the 1.46 MeV photopeak relative height to the negatron spectrum with volume. Further, peak pileup does not readily manifest itself for practical KSr2I5:Eu2+ volumes.

  4. 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.

  5. Technology limits for reducing EU transport sector CO2 emissions.

    PubMed

    Dray, Lynnette M; Schäfer, Andreas; Ben-Akiva, Moshe E

    2012-05-01

    Using a new data set describing the techno-economic characteristics of current and projected future transport technologies and a synthesis of existing transport demand models, lifecycle CO(2) emissions from 27 EU countries (EU27) were estimated in the absence and presence of new policy interventions to 2050. Future CO(2) emissions are strongly dependent on geographical scope and economic growth assumptions, and to a lesser extent on uncertainties in technology characteristics, but in the absence of new policy intervention they continue to rise from present-day values in all three scenarios examined. Consequently, EU27 emissions goals, which may require a 60% decrease in transport sector greenhouse gas emissions from year-1990 values by 2050, will be difficult to meet. This is even the case under widespread adoption of the most promising technologies for all modes, due primarily to limitations in biofuel production capacity and a lack of technologies that would drastically reduce CO(2) emissions from heavy trucks and intercontinental aviation.

  6. Persistent Luminescence in Eu2+-Doped Compounds: A Review

    PubMed Central

    Van den Eeckhout, Koen; Smet, Philippe F.; Poelman, Dirk

    2010-01-01

    In 1996, Matsuzawa et al. reported on the extremely long-lasting afterglow of SrAl2O4:Eu2+ codoped with Dy3+ ions, which was more than 10-times brighter than the previously widely used ZnS:Cu,Co. Since then, research for stable and efficient persistent phosphors has continuously gained popularity. However, even today - almost 15 years after the discovery of SrAl2O4:Eu2+, Dy3+ - the number of persistent luminescent materials is still relatively low. Furthermore, the mechanism behind this phenomenon is still unclear. Although most authors agree on the general features, such as the existence of long-lived trap levels, many details are still shrouded in mystery. In this review, we present an overview of the important classes of known persistent luminescent materials based on Eu2+-emission and how they were prepared, and we take a closer look at the models and mechanisms that have been suggested to explain bright afterglow in various compounds.

  7. Zero-field NMR and NQR studies of magnetically ordered state in charge-ordered EuPtP

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Maruyama, T.; Ueda, K.; Mito, T.; Mitsuda, A.; Umeda, M.; Sugishima, M.; Wada, H.

    2015-03-01

    EuPtP undergoes two valence transitions and has two kinds of valence states of Eu ions at low temperatures. In the charge-ordered state, this compound shows an antiferromagnetic order ascribed to magnetic divalent Eu ions. We investigated the antiferromagnetically ordered state of EuPtP by nuclear magnetic resonance (NMR) measurement and nuclear quadrupole resonance (NQR) measurement in a zero external magnetic field. The observed 153Eu NMR signals of a magnetic divalent state and Eu,153151 NQR signals of a nonmagnetic trivalent state clearly demonstrate that the spins order in the hexagonal basal plane and the internal magnetic field is not canceled out, even at the Eu3 + layers which are in the middle of magnetic Eu2 + layers. In addition, the observation of 31P and 195Pt NMR spectra allowed us to discuss a possible magnetic structure. We also evaluated the nuclear quadrupole frequencies for both Eu2 + and Eu3 + ion states.

  8. EU landfill waste acceptance criteria and EU Hazardous Waste Directive compliance testing of incinerated sewage sludge ash.

    PubMed

    Donatello, S; Tyrer, M; Cheeseman, C R

    2010-01-01

    A hazardous waste assessment has been completed on ash samples obtained from seven sewage sludge incinerators operating in the UK, using the methods recommended in the EU Hazardous Waste Directive. Using these methods, the assumed speciation of zinc (Zn) ultimately determines if the samples are hazardous due to ecotoxicity hazard. Leaching test results showed that two of the seven sewage sludge ash samples would require disposal in a hazardous waste landfill because they exceed EU landfill waste acceptance criteria for stabilised non-reactive hazardous waste cells for soluble selenium (Se). Because Zn cannot be proven to exist predominantly as a phosphate or oxide in the ashes, it is recommended they be considered as non-hazardous waste. However leaching test results demonstrate that these ashes cannot be considered as inert waste, and this has significant implications for the management, disposal and re-use of sewage sludge ash.

  9. 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.

  10. Patterns of clinical mentorship in undergraduate nurse education: A comparative case analysis of eleven EU and non-EU countries.

    PubMed

    Dobrowolska, Beata; McGonagle, Ian; Kane, Roslyn; Jackson, Christine S; Kegl, Barbara; Bergin, Michael; Cabrera, Esther; Cooney-Miner, Dianne; Di Cara, Veronika; Dimoski, Zvonko; Kekus, Divna; Pajnkihar, Majda; Prlić, Nada; Sigurdardottir, Arun K; Wells, John; Palese, Alvisa

    2016-01-01

    In spite of the number of studies available in the field and policy documents developed both at the national and the international levels, there is no reliable data available regarding the variation of roles occupied by clinical mentors (CMs) across countries. To describe and compare the CM's role; responsibilities; qualifications; employment requirements and experience in undergraduate nurse education as enacted in 11 European Union (EU) and non- EU countries. A case study design. A panel of expert nurse educators from 11 countries within and outside of the EU (Croatia, Czech Republic, England, Iceland, Ireland, Italy, Poland, Serbia, Slovenia, Spain, and the USA). A questionnaire containing both quantitative and qualitative questions was developed and agreed by the panel using a Nominal Group Technique (NGT); four cycles of data collection and analysis were conducted involving key experts in nursing education in each country. In all countries, there are at least two types of clinical mentorship dedicated to undergraduate nursing students: the first is offered by higher education institutions, and the second is offered by health care providers. Variation was noted in terms of profile, responsibilities and professional requirements to act as a CM; however, the CM role is mainly carried out by registered nurses, and in most countries there are no special requirements in terms of education and experience. Those who act as CMs at the bedside continue to manage their usual caseload, thus the role adds to their work burden. Whilst it is imperative to have respect for the different national traditions in undergraduate nurse education, the globalisation of the nursing workforce and greater opportunities for student mobility during the course of their undergraduate education suggests that in areas such as clinical mentorship, jurisdictions, particularly within the EU, should work towards greater system harmonisation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Chemical compatibility study between ceramic breeder and EUROFER97 steel for HCPB-DEMO blanket

    NASA Astrophysics Data System (ADS)

    Mukai, Keisuke; Sanchez, Fernando; Knitter, Regina

    2017-05-01

    Chemical compatibility between ceramic breeder (Li4SiO4 + 20 mol% addition of Li2TiO3) and EUROFER97 steel was examined in this study. These materials were contacted and heated at 623, 823 and 1073 K under He + 0.1 vol.% H2 atmosphere for up to 12 weeks. Limited influence was found in the breeder specimens, although losses of the constituent elements appeared near the surface of the breeder pellets heated at 1073 K. For the EUROFER specimens with formation of a corrosion layer, element diffusivity was estimated based on diffusion kinetics. In the temperature range, effective diffusion coefficients of oxygen into EUROFER steel were in the range from 3.5 × 10-14 to 2.5 × 10-12 cm2/s and found to be faster than that of Li. The coefficients yielded an activation energy of 0.93 eV for oxygen diffusion into EUROFER steel and predicted the possible thickness of the corrosion layer after operational periods.

  12. 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.

  13. New strategies to improve the luminescence efficiency of Eu ions embedded in Si-based matrices

    NASA Astrophysics Data System (ADS)

    Boninelli, S.; Bellocchi, G.; Franzò, G.; Miritello, M.; Iacona, F.

    2013-04-01

    The comparison of the performances of SiO2 and SiOC layers as host matrices for optically active Eu ions is presented. A SiO2 matrix allows to observe light emission from both Eu2+ and Eu3+ ions, owing to a proper tuning of the thermal annealing process used for the optical activation of the rare earth. However, the photoluminescence efficiency of both ions remains relatively low and quite far from the requirements for technological applications, mainly due to the extensive formation of Eu-containing precipitates. A detailed study by transmission electron microscopy allowed us to analyze and elucidate the clustering process and to find suitable strategies for minimizing it. We found that the substitution of SiO2 matrix with a SiOC film allows to obtain a very bright light emission centered at about 440 nm from Eu2+ ions. In fact, SiOC is able to efficiently promote the Eu3+ → Eu2+ reduction; furthermore, Eu ions are characterized by an enhanced mobility and solubility in this matrix, and as a consequence, Eu precipitation is strongly reduced. Since SiOC is a material fully compatible with standard Si technology, Eu-doped SiOC layers can be considered a highly interesting candidate for photonic applications.

  14. 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.

  15. Eu(3+) -doped polystyrene and polyvinylidene fluoride nanofibers made by electrospinning for photoluminescent fabric designing.

    PubMed

    Itankar, Sangeeta Gopichandra; Dandekar, Manjusha Prafulla; Kondawar, Subhash Baburao; Bahirwar, Bhaskar Marotrao

    2017-06-21

    Eu(3+) -doped polystyrene and polyvinylidene fluoride (PVDF/Eu(3+) and PS/Eu(3+) ) nanofibers were made using electrospinning. These fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDX) and photoluminescence (PL). Spectral analysis of PVDF/Eu(3+) and PS/Eu(3+) nanofibers was based on their emission spectra. A bright red emission was noticed from Eu(3+) that was assigned to the hypersensitive (5) D0  → (7) F2 transition. The enhanced intensity ratios of (5) D0  → (7) F2 to (5) D0  → (7) F1 transitions in the nanofibers indicated a more polarized chemical environment for the Eu(3+) ions and greater hypersensitivity for the (5) D0  → (7) F2 transition, which showed the potential for application in various polymer optoelectronic devices. The Eu(3+) -doped polymer (PVDF/Eu(3+) and PS/Eu(3+) ) nanofibers are suitable for the photoluminescent white light fabric design of smart textiles. This paper focuses on the potential application of smart fabrics to address challenges in human life. Copyright © 2017 John Wiley & Sons, Ltd.

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

    PubMed Central

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

    2014-01-01

    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. PMID:27877717

  17. Synthesis and optical properties of CaMoO4:Eu3+, Na+ nanophosphors and a transparent CaMoO4:Eu3+, Na+ suspension

    NASA Astrophysics Data System (ADS)

    Kim, Myeong-Jin; Huh, Young-Duk

    2012-12-01

    CaMoO4:Eu3+, Na+ nanophosphors were prepared from Ca-oleate (Eu, Na-oleate) and tetraoctylammonium (TOA)-MoO4 complexes by using a solvothermal reaction. The brightest red-emitting nanophosphor was Ca0.58MoO4:0.21Eu3+, 0.21Na+ prepared at 120 °C. The surfaces of the CaMoO4:Eu3+, Na+ nanophosphors were hydrophobic because of the use of oleylamine as surfactant. A stable scattering-free suspension of Ca0.58MoO4:0.21Eu3+, 0.21Na+ nanophosphor in toluene was also prepared for use in flexible and transparent displays.

  18. An anthropological analysis of European Union (EU) health governance as biopolitics: the case of the EU tissues and cells directive.

    PubMed

    Hoeyer, Klaus

    2010-06-01

    Healthcare in Europe is increasingly influenced by European Union (EU) regulation enacted to harmonise heterogeneous practices through common safety standards. In many instances directives on safety issues evade public debate because they are seen as merely 'technical matters'. In this paper I analyse the implications at a national level in Denmark of one such piece of legislation: the EU Tissues and Cells Directive. The analysis is based on participant observation, interviews and document analysis conducted in the period from May 2007 to June 2009. I follow translations of the Directive from the level of the EU text into national legislation and further into everyday practices. From a biopolitical perspective, I explore the implications of this so-called technical directive that appear necessary for policymakers and yet remain strangely detached from the everyday experiences of people for whom and on whom it is supposed to work. The Directive has serious implications for the allocation of funds, for patients and for healthcare professionals. These implications need to be discussed. Even more basically, the analysis points to a need for discussing what makes so-called technical directives necessary. This article is intended to facilitate this type of debate.

  19. 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.

  20. 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.

  1. Sorption of Eu(III) on granite: EPMA, LA-ICP-MS, batch and modeling studies.

    PubMed

    Fukushi, Keisuke; Hasegawa, Yusuke; Maeda, Koushi; Aoi, Yusuke; Tamura, Akihiro; Arai, Shoji; Yamamoto, Yuhei; Aosai, Daisuke; Mizuno, Takashi

    2013-11-19

    Eu(III) sorption on granite was assessed using combined microscopic and macroscopic approaches in neutral to acidic conditions where the mobility of Eu(III) is generally considered to be high. Polished thin sections of the granite were reacted with solutions containing 10 μM of Eu(III) and were analyzed using EPMA and LA-ICP-MS. On most of the biotite grains, Eu enrichment up to 6 wt % was observed. The Eu-enriched parts of biotite commonly lose K, which is the interlayer cation of biotite, indicating that the sorption mode of Eu(III) by the biotite is cation exchange in the interlayer. The distributions of Eu appeared along the original cracks of the biotite. Those occurrences indicate that the prior water-rock interaction along the cracks engendered modification of biotite to possess affinity to the Eu(III). Batch Eu(III) sorption experiments on granite and biotite powders were conducted as functions of pH, Eu(III) loading, and ionic strength. The macroscopic sorption behavior of biotite was consistent with that of granite. At pH > 4, there was little pH dependence but strong ionic strength dependence of Eu(III) sorption. At pH < 4, the sorption of Eu(III) abruptly decreased with decreased pH. The sorption behavior at pH > 4 was reproducible reasonably by the modeling considering single-site cation exchange reactions. The decrease of Eu(III) sorption at pH < 4 was explained by the occupation of exchangeable sites by dissolved cationic species such as Al and Fe from granite and biotite in low-pH conditions. Granites are complex mineral assemblages. However, the combined microscopic and macroscopic approaches revealed that elementary reactions by a single mineral phase can be representative of the bulk sorption reaction in complex mineral assemblages.

  2. Adsorption and retarded diffusion of EuIII-EDTA- through hard clay rock

    NASA Astrophysics Data System (ADS)

    Descostes, Michael; Pointeau, Ingmar; Radwan, Jean; Poonoosamy, Jenna; Lacour, Jean-Luc; Menut, Denis; Vercouter, Thomas; Dagnelie, Romain V. H.

    2017-01-01

    Adsorption and diffusion experiments of EuIII were performed in Callovo-Oxfordian (COx) clay rock in the presence of EDTA. The predictive model based on binary system parameters (Eu/COx and EDTA/COx) was in good agreement with the results for the Eu/EDTA/COx ternary system. At low EDTA concentrations, the behaviour of EuIII was mainly driven by Eu3+adsorption and complexation by carbonates and EDTA. At higher EDTA concentrations, the behaviour of EuIII was driven by the adsorption of [EuIII-EDTA]- anions. Europium was then used as a probe to estimate the transport of EDTA. Three through-diffusion experiments of EDTA were compared with 14C, Eu and 152Eu tracers. EuIII-EDTA was not quantitatively dissociated by diffusion through the rock. The effective diffusion coefficients quantified De(EuIII-EDTA) = 1.5-1.7 · 1012 m2 s-1 were an order of magnitude lower than that of water, evidencing the anionic exclusion of [EuIII-EDTA]- within the clay rock. Break-through curves and diffusion profiles confirmed retardation due to significant adsorption on the clay rock (Rd(EuIII-EDTA) ∼ 6-14 L kg-1) in comparison with inorganic anions. However, the model based on batch adsorption measurements failed to predict the diffusion results. All experiments displayed an early break-through of EDTA complexes. This behaviour contrasted with results on iron oxides rich sediments, which usually led to higher retardation than expected from the batch studies.

  3. 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.

  4. Optimization of photoluminescence of Y(2)O(3):Eu and Gd(2)O(3):Eu phosphors synthesized by thermolysis of 2,4-pentanedione complexes.

    PubMed

    Antic, B; Rogan, J; Kremenovic, A; Nikolic, A S; Vucinic-Vasic, M; Bozanic, D K; Goya, G F; Colomban, P H

    2010-06-18

    Spherical shaped nanoparticles of series Y(2 - x)Eu(x)O(3) (x = 0.06, 0.10, 0.20, and 2) and Gd(2 - x)Eu(x)O(3) (x = 0.06, 0.10) were prepared by thermolysis of 2,4-pentanedione complexes of Y, Gd, and Eu. The bixbyite phase of Gd(2 - x)Eu(x)O(3) samples was formed at 500 degrees C, whereas the thermal decomposition of Y and Eu complexes' mixtures occurred at higher temperatures. Linearity in the concentration dependence on lattice parameter confirmed the formation of solid solutions. The distribution of Eu(3+) in Gd(2 - x)Eu(x)O(3) was changed with thermal annealing: in the as-prepared sample (x = 0.10) the distribution was preferential at C(3i) sites while in the annealed samples, Eu(3+) were distributed at both C(2) and C(3i) sites. Rietveld refinement of site occupancies as well as emission spectra showed a random distribution of cations in Y(2 - x)Eu(x)O(3). The photoluminescence (PL) measurements of the sample showed red emission with the main peak at 614 nm ((5)D(0)-(7)F(2)). The PL intensity increased with increasing concentration of Eu(3+) in both series. Infrared excitation was required to obtain good Raman spectra. The linear dependence of the main Raman peak wavenumber offers a non-destructive method for monitoring the substitution level and its homogeneity at the micron scale.

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

    DOE PAGES

    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

  6. 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

  7. 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.

  8. Fabrication and optical properties of Y2O3: Eu3+ nanofibers prepared by electrospinning.

    PubMed

    Dong, Guoping; Chi, Yingzhi; Xiao, Xiudi; Liu, Xiaofeng; Qian, Bin; Ma, Zhijun; Wu, E; Zeng, Heping; Chen, Danping; Qiu, Jianrong

    2009-12-07

    Y(2)O(3): Eu(3+) nanofibers with the average diameter of ~300 nm were in situ fabricated by electrospinning. X-ray diffraction (XRD) pattern confirmed that the Y(2)O(3): Eu(3+) nanofibers were composed of pure body-centered cubic (bcc) Y(2)O(3) phase. High-resolution transmission electron microscopy (HRTEM) results indicated that Y(2)O(3): Eu(3+) nanofibers were constituted of nonspherical crystalline grains, and these crystalline grains were orderly arranged along the axial direction of single nanofiber. These Y(2)O(3): Eu(3+) nanofibers showed a partially polarized photoluminescence (PL). The arrangement of crystalline grains and the mismatch of dielectric constant between Y(2)O(3): Eu(3+) nanofiber and its environment probably contributed together to the polarized PL from Y(2)O(3): Eu(3+) nanofiber.

  9. Optical properties of the Eu(III)-La(III)-complex-doped polyolefine film and rod samples

    NASA Astrophysics Data System (ADS)

    Pogreb, Roman; Popov, Oleg; Lirtsman, Vlad; Pyshkin, Oleg; Kazachkov, Alexander; Musin, Albina; Finkelshtein, Binyamin; Shmukler, Yuri; Davidov, Dan; Bormashenko, Edward

    2005-04-01

    The work is devoted to luminescent properties of trivalent lanthanide complexes dispersed in thermoplastic host matrices. Polyethylene-based film and polypropylene-based rod both doped with these complexes were manufactured using an extrusion technique. Two kinds of dopants were used: Eu(III)-thenoyltrifluoroacetone-1,10-phenanthroline complex (Eu(III)) and Eu(III)-La(III)-1,10-phenanthroline complex (Eu(III)-La(III)). Comparison was made between these samples regarding absorption, excitation, emission and a lifetime of luminescence. Dependence of emission intensity on the excitation energy was determined. Emission spectra of the films were studied at room and helium temperatures. Optical properties of Eu(III) samples are different from Eu(III)-La(III) samples. Significant difference in spectra of these two types of samples may be attributed to the La(III) action.

  10. 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.

  11. Structure and luminescence of SrY{sub 2}O{sub 4}:Eu

    SciTech Connect

    Park, S.J.; Park, C.H.; Yu, B.Y.; Bae, H.S.; Kim, C.H.; Pyun, C.H.

    1999-10-01

    Powder samples of SrY{sub 2(1{minus}x)}O{sub 4}:Eu{sub 2x} were prepared at 1,000 C by the combustion method. The emission spectrum of SrY{sub 2}O{sub 4}:Eu{sup 3+} showed two kinds of Eu{sup 3+} emissions, which could be assigned to Eu{sup 3+} ions in the Sr site and the Y site. Reducing SrY{sub 2}O{sub 4}:Eu brought a broad band emission around 470 nm, which could be attributed to crystal defects introduced by the reduction. The energy transfer from defects to Eu{sup 3+} ions was observed to be more effective to the Sr site than to the Y site.

  12. Near infrared emission of Eu2+ ions in Ca3Sc2Si3O12

    NASA Astrophysics Data System (ADS)

    Berezovskaya, I. V.; Dotsenko, V. P.; Voloshinovskii, A. S.; Smola, S. S.

    2013-10-01

    The luminescent properties of Eu2+ ions in Ca3Sc2Si3O12 have been studied for the first time. The Eu2+-doped Ca3Sc2Si3O12 exhibit a broadband emission in the 720-1100 nm region with a maximum at about 840 nm, which is due to the 4f65d → 4f7 transition of Eu2+ ions. This interpretation is supported by the appearance of the fine structure in the emission spectrum of Eu2+-doped Ca3Sc2Si3O12 at 77 K. Probably, the near infrared emission of Eu2+ ions in Ca3Sc2Si3O12 is the most long-wavelength 4f65d → 4f7 emission of these ions within more than three hundreds of Eu2+-doped inorganic compounds studied to date.

  13. High performance oxygen sensing nanofibrous membranes of Eu(III) complex/polystyrene prepared by electrospinning

    NASA Astrophysics Data System (ADS)

    Yingkui, Li

    2011-07-01

    In this paper, we report the synthesis, characterization, crystal structure, and photophysical properties of a Eu 3+ complex of Eu(TTA) 3Phen, where TTA = 2-thenoyltrifluoroacetonate, and Phen = 1,10-phenanthroline. Its elementary application for oxygen-sensing application is also investigated by doping it into a polymer matrix of polystyrene (PS). Experimental data suggest that the 3 wt% doped Eu(TTA) 3Phen nanofibrous membrane exhibits a high sensitivity of 3.4 towards oxygen with a good linear relationship of R2 = 0.996. In addition, the 3 wt% doped Eu(TTA) 3Phen nanofibrous membrane owns a quick response of 9 s towards molecular oxygen, along with its excellent atmosphere insensitivity and photobleaching resistance. All these results suggest that both Eu(TTA) 3Phen and Eu(TTA) 3Phen/PS system are promising candidates for oxygen-sensing optical sensors.

  14. Effective optical Faraday rotations of semiconductor EuS nanocrystals with paramagnetic transition-metal ions.

    PubMed

    Hasegawa, Yasuchika; Maeda, Masashi; Nakanishi, Takayuki; Doi, Yoshihiro; Hinatsu, Yukio; Fujita, Koji; Tanaka, Katsuhisa; Koizumi, Hitoshi; Fushimi, Koji

    2013-02-20

    Novel EuS nanocrystals containing paramagnetic Mn(II), Co(II), or Fe(II) ions have been reported as advanced semiconductor materials with effective optical rotation under a magnetic field, Faraday rotation. EuS nanocrystals with transition-metal ions, EuS:M nanocrystals, were prepared by the reduction of the Eu(III) dithiocarbamate complex tetraphenylphosphonium tetrakis(diethyldithiocarbamate)europium(III) with transition-metal complexes at 300 °C. The EuS:M nanocrystals thus prepared were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroanalysis (ICP-AES), and a superconducting quantum interference device (SQUID) magnetometer. Enhanced Faraday rotations of the EuS:M nanocrystals were observed around 550 nm, and their enhanced spin polarization was estimated using electron paramagnetic resonance (EPR) measurements. In this report, the magneto-optical relationship between the Faraday rotation efficiency and spin polarization is discussed.

  15. 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.

  16. NMR and Mössbauer Study of Al2O3-Eu2O3

    NASA Astrophysics Data System (ADS)

    Nava, N.; Salas, P.; Llanos, M. E.; Pérez-Pastenes, H.; Viveros, T.

    2005-02-01

    Alumina-europia mixed oxides with 5 and 10 wt.% Eu2O3 were studied by Mössbauer spectroscopy, 27Al MAS-NMR and X-ray diffraction (XRD). The samples were prepared by the sol-gel technique. The XRD patterns for the calcined samples show a broad peak around 2 θ = 30° which is assigned to the Eu2O3; after treatment with hydrogen at 1073 K no reduction to Eu+2 or Eu0 was observed. The NMR spectra show three peaks, which are assigned to the octahedral, pentahedral and tetrahedral aluminum sites; the intensity of each peak depends on the concentration of europium ions. The Mössbauer spectra of the calcined samples show a single peak near zero velocity which is attributed to the Eu+3; after H2 treatment at 1073 K similar spectra were obtained, suggesting Eu+3 is not reducibly at this temperature.

  17. 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.

  18. 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.

  19. DNA sensing by a Eu-binding peptide containing a proflavine unit.

    PubMed

    Ancel, Laetitia; Gateau, Christelle; Lebrun, Colette; Delangle, Pascale

    2013-01-18

    Synthesis of a lanthanide-binding peptide (LBP) for the detection of double-stranded DNA is presented. A proflavine moiety was introduced into a high affinity LBP involving two unnatural chelating amino acids in the Ln ion coordination. The Eu(3+)-LBP complex is demonstrated to bind to ct-DNA and to sensitize Eu luminescence. The DNA binding process is effectively detected via the Eu-centered luminescence thanks to the intimate coupling between the LBP scaffold and DNA intercalating unit.

  20. 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

  1. 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.

  2. Effects of Packaging SrI2(Eu) Scintillator Crystals

    SciTech Connect

    Sturm, Benjamin; Cherepy, Nerine; Drury, Owen; Thelin, P; Fisher, S E; Payne, Stephen A.; Burger, Arnold; Boatner, Lynn A; Ramey, Joanne Oxendine; Shah, Kanai; Hawrami, Rastgo

    2011-01-01

    Recent renewed emphasis placed on gamma-ray detectors for national security purposes has motivated 13 researchers to identify and develop new scintillator materials capable of high energy resolution and 14 growable to large sizes. We have discovered that SrI2(Eu) has many desirable properties for gamma-ray 15 detection and spectroscopy, including high light yield of ~90,000 photons/MeV and excellent light yield 16 proportionality. Furthermore, we have demonstrated growth of crack-free 2 diameter boules. We 17 have measured <2.7% FWHM at 662 keV with small detectors (<1 cm3) in direct contact with a 18 photomultiplier tube, and ~3% resolution at 662 keV is obtained for 1 in3 crystals. Due to the 19 hygroscopic nature of SrI2(Eu), proper packaging is required for field use. This work describes a 20 systematic study performed to determine the key factors in the packaging process to optimize 21 performance. These factors include proper polishing of the surface, the geometry of the crystal, 22 reflector materials and windows. A technique based on use of a collimated Cs-137 source was developed 23 to examine light collection uniformity. Employing this technique, we found that when the crystal is 24 packaged properly, the variance in the pulse height at 662 keV from events near the bottom of the 25 crystal compared to those near the top of the crystal could be reduced to <1%. This paper describes the 26 design and engineering of our detector package in order to improve energy resolution of 1 in3-scale 27 SrI2(Eu) crystals.

  3. 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.

  4. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Effect of an Eu{sup 3+} impurity on the antiferrodistortion and ferroelectric instabilities in an EuTiO{sub 3} bulk crystal and thin films

    SciTech Connect

    Zhandun, V. S. Zamkova, N. G.; Zinenko, V. I.

    2015-01-15

    The existence of an antiferrodistortion transition in EuTiO{sub 3} is disputable, and this question needs to be answered. One of the possible causes is the presence of an Eu{sup 3+} impurity in a sample. A nonempirical polarizable ion model is used to study the effect of a trivalent Eu{sup 3+} ion impurity on the antiferrodistortion and ferroelectric instabilities of an EuTiO{sub 3} crystal in the bulk and the thin-film states. Lattice dynamics calculation shows that a bulk impurity-free EuTiO{sub 3} crystal has no unstable modes throughout the entire phase space volume. The addition of an Eu{sup 3+} impurity leads to a significant softening of the rotational mode, the distortion in which makes tetragonal phase I4/mcm (which is experimentally observed) energetically favorable. In going from the bulk crystal to the thin film, the vibration spectrum of the impurity-free film has unstable antiferrodistortion and rotational modes. The addition of an Eu{sup 3+} impurity enhances the antiferrodistortion instability, which fully or partly suppresses ferroelectricity.

  7. Comparing the luminescence processes of YVO4:Eu and core-shell YVO4@YF3 nanocrystals with bulk-YVO4:Eu

    NASA Astrophysics Data System (ADS)

    Shirmane, L.; Feldmann, C.; Pankratov, V.

    2017-01-01

    Comparative analysis of bulk, non-coated and core-shelled nanocrystalline YVO4:Eu was performed by means of time-resolved luminescence and VUV excitation luminescence spectroscopy techniques. Nanocrystalline YVO4:Eu samples - both as-prepared and YF3 core-shelled - have been synthesized by means of a microwave-assisted synthesis in ionic liquids, which allows to obtain 10-12 nm nanoparticles with high crystallinity. The results show noticeable differences between bulk and nanocrystalline YVO4:Eu in photoluminescence experimental data, which explains by influence of the nanocrystal surface. A YF3 core-shell layer around YVO4:Eu nanoparticles partially recovers the intensity of the Eu3+ emission. It is demonstrated that the Eu3+ luminescence recovery is achieved at the expense of the suppression of the intrinsic emission but not due to the passivation of surface loss centers in core-shelled nanocrystals. It is also shown that surface loss processes are the reason of the degradation of energy transfer efficiency from the host lattice to Eu3+ under high-energy excitations in vacuum ultraviolet spectral range.

  8. [The EU drinking water recommendations: objectives and perspectives].

    PubMed

    Blöch, H

    2011-12-01

    Protection of our drinking water resources and provision of safe drinking water are key requirements of modern water management and health policy. Microbiological and chemical quality standards have been established in the EU water policy since 1980, and are now complemented by a comprehensive protection of water as a resource. This contribution reflects a presentation at the scientific conference of the Federal Associations of Physicians and Dentists within the Public Health Service in May 2011 and provides an overview on objectives and challenges for drinking water protection at the European level. © Georg Thieme Verlag KG Stuttgart · New York.

  9. EU Civilian Crisis Management: The Record So Far

    DTIC Science & Technology

    2010-01-01

    R ® is a registered trademark. © Copyright 2010...Ap r – 03 Ju l–0 3 Oc t– 03 Ja n– 04 Ap r – 04 Ju l–0 4 Oc t– 04 Ja n– 05 Ap r – 05 Ju l–0 5 Oc t– 05 Ja n– 06 Ap r – 06 Ju l–0 6 Oc t– 06 Ja n– 07 Ap r ...07 Ju l–0 7 Oc t– 07 Ja n– 08 Ja n– 09 Ap r – 08 Ju l–0 8 Oc t– 08 The European Union’s Civilian-Military Capabilities 11 Table 2.1 EU

  10. 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.

  11. 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.

  12. 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.

  13. Theoretical and empirical investigations of KCl:Eu2+ for nearly water-equivalent radiotherapy dosimetry

    PubMed Central

    Zheng, Yuanshui; Han, Zhaohui; Driewer, Joseph P.; Low, Daniel A.; Li, H. Harold

    2010-01-01

    Purpose: The low effective atomic number, reusability, and other computed radiography-related advantages make europium doped potassium chloride (KCl:Eu2+) a promising dosimetry material. The purpose of this study is to model KCl:Eu2+ point dosimeters with a Monte Carlo (MC) method and, using this model, to investigate the dose responses of two-dimensional (2D) KCl:Eu2+ storage phosphor films (SPFs). Methods: KCl:Eu2+ point dosimeters were irradiated using a 6 MV beam at four depths (5–20 cm) for each of five square field sizes (5×5–25×25 cm2). The dose measured by KCl:Eu2+ was compared to that measured by an ionization chamber to obtain the magnitude of energy dependent dose measurement artifact. The measurements were simulated using DOSXYZnrc with phase space files generated by BEAMnrcMP. Simulations were also performed for KCl:Eu2+ films with thicknesses ranging from 1 μm to 1 mm. The work function of the prototype KCl:Eu2+ material was determined by comparing the sensitivity of a 150 μm thick KCl:Eu2+ film to a commercial BaFBr0.85I0.15:Eu2+-based SPF with a known work function. The work function was then used to estimate the sensitivity of a 1 μm thick KCl:Eu2+ film. Results: The simulated dose responses of prototype KCl:Eu2+ point dosimeters agree well with measurement data acquired by irradiating the dosimeters in the 6 MV beam with varying field size and depth. Furthermore, simulations with films demonstrate that an ultrathin KCl:Eu2+ film with thickness of the order of 1 μm would have nearly water-equivalent dose response. The simulation results can be understood using classic cavity theories. Finally, preliminary experiments and theoretical calculations show that ultrathin KCl:Eu2+ film could provide excellent signal in a 1 cGy dose-to-water irradiation. Conclusions: In conclusion, the authors demonstrate that KCl:Eu2+-based dosimeters can be accurately modeled by a MC method and that 2D KCl:Eu2+ films of the order of 1 μm thick would have

  14. 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.

  15. 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

  16. Effect of Sr doping in layered Eu3Bi2S4F4 superconductor

    NASA Astrophysics Data System (ADS)

    Zhang, Pan; Zhai, Hui-Fei; Wang, Zhen; Chen, Jian; Feng, Chun-Mu; Cao, Guang-Han; Xu, Zhu-An

    2017-01-01

    We report the effect of Sr-doping in the BiS2-based superconductor {{Eu}}3-xSr x Bi2S4F4. Eu3Bi2S4F4 is a self-doped compound with a mixed Eu valence state. By the partial substitution of Sr for Eu, T c gradually decreases and superconductivity disappears above 0.3 K when x\\gt 1.0. Magnetic-susceptibility and specific-heat measurements reveal that Sr substitution leads to a decrease in both Eu2+ and Eu3+ populations. The decreased Eu3+ population, and the corresponding lower charge carrier density, may be the main origin for the suppression of superconductivity. In addition, we find a significant increase in the Sommerfeld coefficient {γ }0 upon Sr doping, which may be due to the Kondo effect between the magnetic moments (associated to Eu2+ ions) and the conducting electrons. This work implies that the Kondo effect could compete with superconductivity in Eu3Bi2S4F4.

  17. Data Resource Profile: The European Union Statistics on Income and Living Conditions (EU-SILC).

    PubMed

    Arora, Vishal S; Karanikolos, Marina; Clair, Amy; Reeves, Aaron; Stuckler, David; McKee, Martin

    2015-04-01

    Social and economic policies are inextricably linked with population health outcomes in Europe, yet few datasets are able to fully explore and compare this relationship across European countries. The European Union Statistics on Income and Living Conditions (EU-SILC) survey aims to address this gap using microdata on income, living conditions and health. EU-SILC contains both cross-sectional and longitudinal elements, with nationally representative samples of individuals 16 years and older in 28 European Union member states as well as Iceland, Norway and Switzerland. Data collection began in 2003 in Belgium, Denmark, Ireland, Greece, Luxembourg and Austria, with subsequent expansion across Europe. By 2011, all 28 EU member states, plus three others, were included in the dataset. Although EU-SILC is administered by Eurostat, the data are output-harmonized so that countries are required to collect specified data items but are free to determine sampling strategies for data collection purposes. EU-SILC covers approximately 500,000 European residents for its cross-sectional survey annually. Whereas aggregated data from EU-SILC are publicly available [http://ec.europa.eu/eurostat/web/income-and-living-conditions/data/main-tables], microdata are only available to research organizations subject to approval by Eurostat. Please refer to [http://epp.eurostat.ec.europa.eu/portal/page/portal/microdata/eu_silc] for further information regarding microdata access.

  18. Scintillation properties of Eu-doped CsCl and CsBr crystals

    NASA Astrophysics Data System (ADS)

    Saeki, Keiichiro; Koshimizu, Masanori; Fujimoto, Yutaka; Yanagida, Takayuki; Okada, Go; Yahaba, Takuma; Tanaka, Hironori; Asai, Keisuke

    2016-11-01

    Eu-doped CsCl and CsBr crystals were grown by the vertical Bridgman-Stockbarger method and the scintillation properties of the crystals were investigated. The radioluminescence (RL) bands of CsCl:Eu were observed at 245-270 nm and 450 nm. The former bands are attributed to Auger-free luminescence, and the latter band is attributed to Eu2+ 5d-4f transitions. CsBr:Eu showed an RL band at 435 nm, and this broad band is attributed to Eu2+ 5d-4f transitions. The scintillation decay-time constants of the slow components for CsCl:Eu and CsBr:Eu were 0.38 and 2.8 μs, respectively. Based on the pulse-height spectra for 662 keV gamma ray from 137Cs, the light yield of CsCl:Eu and CsBr:Eu are estimated to be 1700 and 2500 photons/MeV, respectively.

  19. Effect of Photonic Structure on Optical Properties of YVO4:Eu3+ Phosphor

    NASA Astrophysics Data System (ADS)

    Thakur, Shashi; Dhiman, Naresh; Sharma, Amit; Gathania, Arvind K.

    2017-04-01

    Polymethyl methacrylate (PMMA) photonic crystal has been prepared on quartz substrate by the self-assembly vertical deposition technique. YVO4:Eu3+ inverse opal was obtained by annealing PMMA photonic crystal infiltrated with YVO4:Eu3+ nanophosphors at 500°C for 3 h. Scanning electron microscopy confirmed the development of the photonic and inverse opal structures. Photoluminescence study showed that the luminescence characteristics depended on the position of the photonic stop band. It was observed that the photoluminescence intensity of YVO4:Eu3+ inverse opal was enhanced near the photonic stop bandgap edge as compared with the intensity of a YVO4:Eu3+ nanophosphor powder sample.

  20. First-principles study of luminescence in Eu2+-doped inorganic scintillators

    NASA Astrophysics Data System (ADS)

    Chaudhry, A.; Boutchko, R.; Chourou, S.; Zhang, G.; Grønbech-Jensen, N.; Canning, A.

    2014-04-01

    Luminescence in Eu2+ activated materials corresponds to a transition from an excited state where the lowest Eu 5d level is filled with one electron [often called the (Eu2+)* state] to the ground state with a half-filled 4f shell with seven electrons of the same spin. We have performed theoretical calculations based on density functional theory to determine the ground state band structure of Eu-doped materials as well as study the (Eu2+)* excited state. Calculations were performed on Eu-doped materials, experimentally known to be either scintillators or nonscintillators, in order to relate theoretically calculable parameters to experimentally observed properties. Applying criteria previously developed for Ce-doped systems [A. Canning, A. Chaudhry, R. Boutchko, and N. Grønbech-Jensen, Phys. Rev. B 83, 125115 (2011), 10.1103/PhysRevB.83.125115] to new Eu-doped materials, we developed a list of candidate materials for new bright Eu-activated scintillators. Ba2CsBr5:Eu is an example of a new bright scintillator from our candidate list that has been synthesized in microcrystalline powder form. As discussed in our previous paper on Ce-doped materials, this approach was designed as a systematic high-throughput method to aid in the discovery of new bright scintillator materials by prioritization and down-selection on the large number of potential new materials.

  1. A facile method for the preparation of Eu{sup 2+}-doped nanocrystalline BaFCl

    SciTech Connect

    Wang, Xianglei; Liu, Zhiqiang; Stevens-Kalceff, Marion A.; Riesen, Hans

    2013-10-15

    Graphical abstract: - Highlights: • A facile co-precipitation method for the preparation of Eu{sup 2+}-doped BaFCl. • Reduction of Eu{sup 3+} to Eu{sup 2+} by zinc granular under nitrogen flow. • Photoluminescence and cathodoluminescence spectroscopy of the as-prepared BaFCl:Eu{sup 2+}. • Temperature dependent photoluminescence properties of Eu{sup 2+} ions in BaFCl. - Abstract: A facile method for the preparation of Eu{sup 2+}-doped BaFCl is reported. The method is based on the co-precipitation of aqueous solutions of BaCl{sub 2} and NH{sub 4}F to yield BaFCl. The doping by europium in the 2+ oxidation state is realized by the reduction of Eu{sup 3+} to Eu{sup 2+} employing granular zinc in the BaCl{sub 2} solution under nitrogen. Powder X-ray diffraction and electron microscopy have been used to confirm the BaFCl phase and photoluminescence, in the temperature range of 2.5–290 K, and room-temperature cathodoluminescence spectra have been measured to characterize the Eu{sup 2+} ions in the sample.

  2. 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.

  3. 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.

  4. Effect of Photonic Structure on Optical Properties of YVO4:Eu3+ Phosphor

    NASA Astrophysics Data System (ADS)

    Thakur, Shashi; Dhiman, Naresh; Sharma, Amit; Gathania, Arvind K.

    2016-11-01

    Polymethyl methacrylate (PMMA) photonic crystal has been prepared on quartz substrate by the self-assembly vertical deposition technique. YVO4:Eu3+ inverse opal was obtained by annealing PMMA photonic crystal infiltrated with YVO4:Eu3+ nanophosphors at 500°C for 3 h. Scanning electron microscopy confirmed the development of the photonic and inverse opal structures. Photoluminescence study showed that the luminescence characteristics depended on the position of the photonic stop band. It was observed that the photoluminescence intensity of YVO4:Eu3+ inverse opal was enhanced near the photonic stop bandgap edge as compared with the intensity of a YVO4:Eu3+ nanophosphor powder sample.

  5. Enhanced red luminescence in Gd2O3:Eu3+,Sm3+ and its dependence on temperature

    NASA Astrophysics Data System (ADS)

    Wu, Xiaofeng; Hu, Shigang; Tan, Congbing; Liu, Yunxin

    2014-10-01

    Here, we show that co-activation in the Gd3+-Eu3+-Sm3+ system can generate the intense red emission from Eu3+ ion. Gd2O3:Sm3+,Eu3+ colloidal spheres were synthesized by combining a low temperature hydrothermal process and a higher temperature of pyrolysis. Under the excitation of 380 nm near UV light, Gd2O3:Sm3+,Eu3+ emits intense red light while the reference Gd2O3:Eu3+ emits very weak one. The calculated polarizability αbμ based on the shift (16 nm) of Eu3+-O2- charge transfer band and the crystallography analysis revealed that Sm3+ ions codoping in Gd2O3:Eu3+ has generated a coordinating environment of Eu3+ ions with high polarizability and low symmetry which leads to high energy transfer rate not only between Sm3+ and Eu3+ pairs, but also between Eu3+(S6) and Eu3+(C2) pairs, ensuring the efficient excitation of Gd2O3:Eu3+,Sm3+. The energy migration from Sm3+ to Eu3+ and a corresponding feedback were also experimentally evidenced by the fluorescent decay, which is in well agreement with the theoretical calculation. In addition, the thermal stability of the photoluminescence in Gd2O3:Eu3+,Sm3+ colloidal spheres was evaluated.

  6. Crystal-site engineering control for the reduction of Eu(3+) to Eu(2+) in CaYAlO4: structure refinement and tunable emission properties.

    PubMed

    Zhang, Yang; Li, Xuejiao; Li, Kai; Lian, Hongzhou; Shang, Mengmeng; Lin, Jun

    2015-02-04

    In this article, Eu-activated CaYAlO4 aluminate phosphors were synthesized by a solid-state reaction. Under UV light excitation, characteristic red line emission of Eu(3+) was detected in the range of 570-650 nm. In addition, we introduced crystal-site engineering approach into the CaYAlO4 host through incorporation of Si(4+)-Ca(2+) to replace Al(3+)-Y(3+), which would shrink the AlO6 octahedrons, accompanied by the expansion of CaO9 polyhedron, and then enable the partial reduction of Eu(3+) to Eu(2+). The crystal structure and underlying mechanism have been clarified on the basis of the Rietveld refinement analysis. The PL spectra of Ca0.99+xY1-xAl1-xSixO4:Eu0.01 (x = 0-0.30) exhibit both green emission of Eu(2+) (4f(6)5d(1)-4f(7), broadband around 503 nm) and red-orange emission of Eu(3+) ((5)D0-(7)F1,2, 593 and 624 nm) under UV light excitation with a quantum yield of 38.5%. The CIE coordinates of Ca0.99+xY1-xAl1-xSixO4:Eu0.01 (x = 0-0.30) phosphors are regularly shifted from (0.482, 0.341) to (0.223, 0.457) with increasing x, which would expand the application of Eu. Furthermore, this investigation reveals the correlations of structure and property of luminescent materials, which would shed light on the development of novel phosphors suitable for lighting and display applications.

  7. 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.

  8. Formation and spectral probing of transparent oxyfluoride glass-ceramics containing (Eu2+, Eu3+:BaGdF5) nano-crystals

    NASA Astrophysics Data System (ADS)

    Biswas, Kaushik; Balaji, S.; Karmakar, Prantik; Annapurna, K.

    2015-01-01

    In the present study, we report the formation of transparent glass-ceramics containing BaGdF5 nanocrystals under optimum ceramization of SiO2-BaF2-K2O-Sb2O3-GdF3-Eu2O3 based oxyfluoride glass and the energy transfer mechanisms in Eu2+ → Eu3+ and Gd3+ → Eu3+ has been interpreted through luminescence study. The modification of local environment surrounding dopant ion in glass and glass ceramics has been studied using Eu3+ ion as spectral probe. The optimum ceramization temperature was determined from the differential scanning calorimetry (DSC) thermogram which revealed that the glass transition temperature (Tg), the crystallization onset temperature (Tx), and crystallization peak temperature (Tp) are 563 °C, 607 °C and 641 °C, respectively. X-ray diffraction pattern of the glass-ceramics sample displayed the presence of cubic BaGdF5 phase (JCPDS code: 24-0098). Transmission electron microscopy image of the glass-ceramics samples revealed homogeneous distribution of spherical fluoride nanocrystals ranging 5-15 nm in size. The emission transitions from the higher excited sates (5DJ, J = 1, 2, and 3) as well as lowered asymmetry ratio of the 5D0 → 7F2 transition (forced electric dipole transition) to that of the 5D0 → 7F1 transition (magnetic dipole) of Eu3+ in the glass-ceramics when compared to glass sample demonstrated the incorporation of dopant Eu3+ ions into the cubic BaGdF5 nanocrystals with higher local symmetry with enhanced ionic nature. The presence of absorption bands of Eu2+ ions and Gd3+ ions present in the glass matrix or fluoride nanocrystals in the excitation spectra of Eu3+ by monitoring emission at 614 nm indicated energy transfer from (Eu2+ → Eu3+) and (Gd3+ → Eu3+) in both glass and glass-ceramics samples.

  9. Eu accession and its consequences for Czech professionals.

    PubMed

    den Exter, André

    2004-01-01

    In March 2003, the Erasmus University Rotterdam (The Netherlands) organised a conference on EU accession and its consequences for applicant countries' health systems. One of the sessions dealt with health professionals. Questions raised during this meeting concerned the impact of accession on medical doctors, in particularly the options of new member state nationals to practice their profession in another member state, and the reverse. It appeared that there are several (legal) barriers for border crossing professionals. This issue is of extreme importance to both the EU, its member states and the applicant countries. Therefore, it is of importance that Czech health professionals participate in this debate. Due to many uncertainties in the pre-accession stage, the conference could not give a clear answer to all the questions. This contribution is an attempt to enhance the national debate on potential consequences of the free movement of persons to the Czech Republic by explaining the European legal context of free movement of persons and to make some critical remarks on the Czech situation.

  10. Antibiotic stewardship implementation in the EU: the way forward.

    PubMed

    Allerberger, Franz; Gareis, Roland; Jindrák, Vlastimil; Struelens, Marc J

    2009-12-01

    There is an urgent need for an agreement on the principles and key components of antibiotic stewardship to support the EU member states in developing their national or regional programs. A proposal for a conceptual framework was drafted during an international expert workshop on hospital antibiotic stewardship organized under the Czech presidency in Prague on 15 April 2009. This document aims at defining structural and organizational requirements to optimize antibiotic use for hospitalized patients. Optimization should aim at improving patient outcomes, ensuring cost-effective therapy, and reducing the adverse health and ecological effects of antimicrobial use, including drug resistance. Antibiotic stewardship is of relevance to hospital as well as community care. To progress on antibiotic stewardship implementation in the EU, we suggest that three issues need to be addressed: the need for further research on the comparative effectiveness and cost-effectiveness of antibiotic stewardship strategies and interventions in different healthcare settings, the development of expert consensus on key elements of evidence-based best practice in hospital and community antibiotic stewardship, and strengthening the legal basis and core funding of antibiotic stewardship programs as integral components of quality and efficiency of care promotion initiatives.

  11. Municipal solid waste development phases: Evidence from EU27.

    PubMed

    Vujić, Goran; Gonzalez-Roof, Alvaro; Stanisavljević, Nemanja; Ragossnig, Arne M

    2015-12-01

    Many countries in the European Union (EU) have very developed waste management systems. Some of its members have managed to reduce their landfilled waste to values close to zero during the last decade. Thus, European Union legislation is very stringent regarding waste management for their members and candidate countries, too. This raises the following questions: Is it possible for developing and developed countries to comply with the European Union waste legislation, and under what conditions? How did waste management develop in relation to the economic development in the countries of the European Union? The correlation between waste management practices and economic development was analysed for 27 of the European Union Member States for the time period between 1995 and 2007. In addition, a regression analysis was performed to estimate landfilling of waste in relation to gross domestic product for every country. The results showed a strong correlation between the waste management variables and the gross domestic product of the EU27 members. The definition of the municipal solid waste management development phases followed a closer analysis of the relation between gross domestic product and landfilled waste. The municipal solid waste management phases are characterised by high landfilling rates at low gross domestic product levels, and landfilling rates near zero at high gross domestic product levels. Hence the results emphasize the importance of wider understanding of what is required for developing countries to comply with the European Union initiatives, and highlight the importance of allowing developing countries to make their own paths of waste management development.

  12. Incorporation of Eu(III) into Calcite under Recrystallization conditions.

    PubMed

    Hellebrandt, S E; Hofmann, S; Jordan, N; Barkleit, A; Schmidt, M

    2016-09-13

    The interaction of calcite with trivalent europium under recrystallization conditions was studied on the molecular level using site-selective time-resolved laser fluorescence spectroscopy (TRLFS). We conducted batch studies with a reaction time from seven days up to three years with three calcite powders, which differed in their specific surface area, recrystallization rates and impurities content. With increase of the recrystallization rate incorporation of Eu(3+) occurs faster and its speciation comes to be dominated by one species with its excitation maximum at 578.8 nm, so far not identified during previous investigations of this process under growth and phase transformation conditions. A long lifetime of 3750 μs demonstrates complete loss of hydration, consequently Eu must have been incorporated into the bulk crystal. The results show a strong dependence of the incorporation kinetics on the recrystallization rate of the different calcites. Furthermore the investigation of the effect of different background electrolytes (NaCl and KCl) demonstrate that the incorporation process under recrystallization conditions strongly depends on the availability of Na(+). These findings emphasize the different retention potential of calcite as a primary and secondary mineral e.g. in a nuclear waste disposal site.

  13. Is EU/EEA population protected from polio?

    PubMed

    Nijsten, Dre; Carrillo-Santisteve, P; Miglietta, A; Ruitenberg, J; Lopalco, P L

    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.

  14. Environmental Impact of Eu Policies On Acheloos River Basin, Greece

    NASA Astrophysics Data System (ADS)

    Skoulikidis, N.; Nikolaidis, N. P.; Oikonomopoulou, A.; Batzias, F.

    The environmental impact of EU policies aiming at protecting surface and ground wa- ters are being assessed in the Acheloos River Basin, Greece as part of a Joint Research Centre (JRC) / DG Environment (DG Env) funded project. The basin offers the possi- bility of studying the impact of EU policies on a multitude of aquatic ecosystems: four artificial and four natural lakes and a large estuary with important hydrotops (lagoons, coastal salt lacustrine and freshwater marshes, etc.) that belong to the NATURA 2000 sites or are protected by the RAMSAR Convention. A database has been developed that includes all available information on sources, fluxes, and concentration levels of nutrients and selected heavy metals from prior and current research programs at the Acheloos River Basin and coastal environment. This information has been used to identify the environmental pressures and develop nutrient budgets for each sub-basin of the watershed to assess the relative contributions of nutrients from various land uses. The mathematical model HSPF is being used to model the hydrology and nitro- gen fate and transport in the watershed. Management scenarios will be developed and modelling exercises will be carried out to assess the impacts of the scenarios. Eco- nomic analysis of the nutrient management scenarios will be conducted to evaluate the costs associated with management practices for reaching acceptable water quality status.

  15. The EU paediatric regulation: effects on paediatric psychopharmacology in Europe.

    PubMed

    Stoyanova-Beninska, Violeta V; Wohlfarth, Tamar; Isaac, Maria; Kalverdijk, Luuk J; van den Berg, Henk; Gispen-de Wied, Christine

    2011-08-01

    Child and adolescent psychiatry is a relatively young field and the recognition, classification, and treatment of disorders in children and adolescents lag behind those in adults. In recent years there is an increasing awareness of the differences between children and adults in psychopathology and pharmacology. Related to this new paediatric regulations have been introduced. This article reviews the regulatory and legislative measures that were adopted in the EU in 2007 and the subsequent impact of these measures on the field of paediatric psychopharmacology. The consequences of the paediatric regulation in the EU are reflected in several domains: regulatory, research aimed at drug development and clinical practices. In the regulatory domain, the consequences include: new paediatric indications, inclusion of special (class) warnings, specification of dose regimens, and information on safety specific to children and adolescents, and development of new medicinal formulations. The paediatric regulation leads to timely development of paediatric friendly formulations and better quality of the clinical evidence. In clinical practices, an increased awareness of the uniqueness of paediatric pharmacology is emerging among medical professionals, and subsequent improvement of medical care (i.e. correct doses, appropriate formulation, monitoring for expected adverse events). In addition, clinical guidelines will have to be revised more frequently in order to integrate the recently acquired knowledge. The new regulations stimulate transparency and discussions between academia, pharmaceutical industry, and regulators. The purpose is to optimize clinical research and obtain evidence for paediatric psychopharmacology, thereby providing adequate support for treatment.

  16. Polarized emission from KCl:Eu2+ single crystals

    NASA Astrophysics Data System (ADS)

    Kang, Jun-Gill; Sohn, Youngku; Nah, Min-Kook; Kim, Youn-Doo; Ogryzlo, Elmer A.

    2000-04-01

    The polarization emission spectrum and the angular dependence of polarization ratio of the blue emission from KCl:Eu2+ were investigated at 78.8 K. The polarized emission at 420 nm consisted of several components. The angular dependence of polarization ratio of each component is proportional to sin(2icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> ) or -cos(2icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> ), when the exciting light is polarized at icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> with respect to the z -axis for the [100]-[010] optical arrangement. The relaxed excited states (RESs) of Eu2+ responsible for the 420 nm emission are presented in terms of the adiabatic potential energy surface (APES), taking into account the Jahn-Teller effect (JTE) coupling to the Eg mode and the spin-orbit (SO) interaction. The charge-compensating cation vacancy (CCV, Vc - ) also causes an additive perturbation.

  17. EU legislations affecting safety data availability of cosmetic ingredients.

    PubMed

    Pauwels, Marleen; Rogiers, Vera

    2007-12-01

    With the introduction of the 6th and 7th Amendments (OJ L151, 32-37, 23 June 1993; OJ L066, 26-35, 11 March 2003) to the Cosmetic Products Directive (OJ L262, 169-200, 27 September 1976), imposing a testing and marketing ban on cosmetic products tested on animals, the retrieval of toxicological data on individual ingredients became of greater need. Since the majority of cosmetic ingredients are used for many other purposes than their cosmetic function, they fall under the scope of more than one EU Directive. An overview is given of EU legislation that could potentially affect the availability and interpretation of cosmetic safety data. It will become clear that, although cosmetics are regulated by a specific so-called "vertical" legislation, "horizontal" influences from other products' legislations play a role since they determine the type and amount of data that theoretically could be found on the specific substances they regulate. This knowledge is necessary while performing extended searches in databases and becomes indispensable when initiating negotiations with manufacturers or suppliers for obtaining the safety data required.

  18. Incorporation of Eu(III) into Calcite under Recrystallization conditions

    PubMed Central

    Hellebrandt, S. E.; Hofmann, S.; Jordan, N.; Barkleit, A.; Schmidt, M.

    2016-01-01

    The interaction of calcite with trivalent europium under recrystallization conditions was studied on the molecular level using site-selective time-resolved laser fluorescence spectroscopy (TRLFS). We conducted batch studies with a reaction time from seven days up to three years with three calcite powders, which differed in their specific surface area, recrystallization rates and impurities content. With increase of the recrystallization rate incorporation of Eu3+ occurs faster and its speciation comes to be dominated by one species with its excitation maximum at 578.8 nm, so far not identified during previous investigations of this process under growth and phase transformation conditions. A long lifetime of 3750 μs demonstrates complete loss of hydration, consequently Eu must have been incorporated into the bulk crystal. The results show a strong dependence of the incorporation kinetics on the recrystallization rate of the different calcites. Furthermore the investigation of the effect of different background electrolytes (NaCl and KCl) demonstrate that the incorporation process under recrystallization conditions strongly depends on the availability of Na+. These findings emphasize the different retention potential of calcite as a primary and secondary mineral e.g. in a nuclear waste disposal site. PMID:27618958

  19. Luminescent properties of Eu3+-doped yttrium or gadolinium phosphates

    NASA Astrophysics Data System (ADS)

    Tuan, D. C.; Olazcuaga, R.; Guillen, F.; Garcia, A.; Moine, B.; Fouassier, C.

    2005-03-01

    After an investigation of the formation conditions of the intermediate phases existing in the systems Y{2}O{3}-P{2}O{5} and Gd{2}O{3}-P{2}O{5} (R/P = 4/1, 3/1, 1, 1/2, 1/3 and 1/5 (R = Y or Gd)) the luminescence characteristics of the Eu3+ ion substituted for the Y3+ or Gd3+ ions have been determined. The position of the O2-toEu3+ charge transfer band shifts to higher energies with increasing P content, which results in high quantum efficiencies for several P-rich phosphates. With increasing P content the probability of the electric dipole transitions is reduced, in particular for the hypersensitive 5D{0}to 7F{2} transition. This causes a shift of the colour point to the orange and lengthens the luminescence lifetime. The luminescence characteristics are compared with those of the red phosphors for display.

  20. Incorporation of Eu(III) into Calcite under Recrystallization conditions

    NASA Astrophysics Data System (ADS)

    Hellebrandt, S. E.; Hofmann, S.; Jordan, N.; Barkleit, A.; Schmidt, M.

    2016-09-01

    The interaction of calcite with trivalent europium under recrystallization conditions was studied on the molecular level using site-selective time-resolved laser fluorescence spectroscopy (TRLFS). We conducted batch studies with a reaction time from seven days up to three years with three calcite powders, which differed in their specific surface area, recrystallization rates and impurities content. With increase of the recrystallization rate incorporation of Eu3+ occurs faster and its speciation comes to be dominated by one species with its excitation maximum at 578.8 nm, so far not identified during previous investigations of this process under growth and phase transformation conditions. A long lifetime of 3750 μs demonstrates complete loss of hydration, consequently Eu must have been incorporated into the bulk crystal. The results show a strong dependence of the incorporation kinetics on the recrystallization rate of the different calcites. Furthermore the investigation of the effect of different background electrolytes (NaCl and KCl) demonstrate that the incorporation process under recrystallization conditions strongly depends on the availability of Na+. These findings emphasize the different retention potential of calcite as a primary and secondary mineral e.g. in a nuclear waste disposal site.

  1. Nonlinear electrostrictive lattice response of EuTiO3

    NASA Astrophysics Data System (ADS)

    Pappas, P.; Calamiotou, M.; Köhler, J.; Bussmann-Holder, A.; Liarokapis, E.

    2017-07-01

    An epitaxial EuTiO3 (ETO) film grown on the SrTiO3 substrate was studied at room temperature with synchrotron XRD and in situ application of an electric field (nominally up to 7.8 kV/cm) in near grazing incidence geometry, in order to monitor the response of the lattice to the field. 2D diffraction images show that apparently misoriented coherently diffracting domains are present close to the surface whereas the film diffracts more as a single crystal towards the interface. Diffraction intensity profiles recorded from the near surface region of the EuTiO3 film showed systematic modifications upon the application of the electric field, indicating that at a critical electric field (nominally above 3.1 kV/cm), there is a clear change in the lattice response to the field, which was much stronger when the field was almost parallel to the diffraction vector. The data suggest that the ETO film, nominally paraelectric at room temperature, transforms under the application of a critical electric field to piezoelectric in agreement with a theoretical analysis based on a double-well potential. In order to exclude effects arising from the substrate, this has been investigated separately and shown not to be affected by the field.

  2. Partnerships for disaster risk insurance in the EU

    NASA Astrophysics Data System (ADS)

    Mysiak, Jaroslav; Dionisio Pérez-Blanco, C.

    2016-11-01

    With increasing costs inflicted by natural hazard perils, and amidst state budget cuts, concerns are mounting about the capacity of governments to design sustainable, equitable and affordable risk management schemes. The participation of the private sector along with the public one through public-private partnerships (PPPs) has gained importance as a means of providing catastrophic natural hazard insurance to address these seemingly conflicting objectives. In 2013 the European Commission launched a wide-ranging consultation about what EU action could be appropriate to improve the performance of insurance markets. Simultaneously, the EU legislator instigated major reforms in the legislation and regulations that pertain to how PPPs are designed or operate. This paper has a dual objective: first, we review and summarize the manifold legal background that influences the provision of insurance against natural catastrophes. Second, we examine how PPPs designed for sharing and transferring risk operate within the European regulatory constraints, illustrated using the example of the UK Flood Reinsurance Scheme (Flood RE) between the state and the Association of British Insurers.

  3. X-ray induced luminescence properties of (Y,Eu)AlO3 single crystals

    NASA Astrophysics Data System (ADS)

    Kuro, Tomoaki; Nakauchi, Daisuke; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

    2017-02-01

    We investigated photoluminescence, scintillation and dosimeter properties of (Y1-x Eux)AlO3 (x = 0.001, 0.5 and 1) single crystals (hereafter denoted as Eu:YAP for x = 0.001, EYAP for x = 0.5 and EAP for x = 1). The samples were prepared by the Floating Zone method. In photoluminescence (PL), we observed a broad emission around 300-400 nm due to host under excitation of 280 nm, and emissions due to the 4f state transitions of Eu3+ appeared around 590 nm and 615 nm. Scintillation spectra also show emission peaks around 590 and 615 nm due to the 4f state transitions of Eu3+ in all the samples. In addition, emissions around 300-400 nm due to YAP host and around 550-700 nm due to 5d-4f transitions of Eu2+ appeared in Eu:YAP. The PL and scintillation decay time profiles consisted of several exponential decay components. The fast (ns) component group was possibly due to host emission, and especially Eu:YAP demonstrated a very fast PL decay time of 16 ns. The intermediate (μs) component group was due to the 5d-4f transitions of Eu2+. The slow (ms) component group was ascribed to the 4f state transitions of Eu3+ ion. The Eu:YAP sample showed intense thermally-stimulated luminescence (TSL) with peaks at 46, 155, 255 and 443 °C. The intensity was much higher than those of EAP and EYAP. In particular, the peak at 254 °C, which showed the highest intensity, was due to doping with Eu. The TSL dose response function showed a good linearity (R2 > 0.99) over a wide dose range from 0.1 mGy to 100 mGy for Eu:YAP, which showed the highest sensitivity among the present samples.

  4. Dual preparation of hydrophobic and hydrophilic BaWO{sub 4}:Eu phosphors

    SciTech Connect

    Cho, Young-Sik; Huh, Young-Duk

    2016-06-15

    Highlights: • Red-emitting BaWO{sub 4}:Eu phosphors were prepared in hexane-water bilayer system. • The hydrophobic nanometer-sized BaWO{sub 4}:Eu phosphors were obtained in hexane. • The hydrophilic micrometer-sized BaWO{sub 4}:Eu dendrites were obtained in water. - Abstract: BaWO{sub 4}:Eu phosphors were prepared by performing a solvothermal reaction in a water–hexane bilayer system. A barium oleate (and europium oleate) complex was obtained in hexane via a phase transfer reaction involving Ba{sup 2+} (and Eu{sup 3+}) ions in an aqueous solution of sodium oleate. The outer surfaces of the nanometer-sized BaWO{sub 4}:Eu phosphors were capped by the long alkyl chain of oleate; therefore, the hydrophobic nanometer-sized BaWO{sub 4}:Eu phosphors preferentially dissolved in the hexane layer. The micrometer-sized BaWO{sub 4}:Eu phosphors were obtained in the water layer. The BaWO{sub 4}:Eu phosphors prepared in hexane and water yielded sharp strong absorption and emission peaks at 464 and 615 nm, respectively, due to the {sup 7}F{sub 0} → {sup 5}D{sub 2} and the {sup 5}D{sub 0} →{sup 7} F{sub 2} transitions of the Eu{sup 3+} ions. The BaWO{sub 4}:Eu phosphors are good candidate red-emitting phosphors for use in InGaN blue-emitting diodes, which have an emission wavelength of 465 nm.

  5. [Effect of PEG400 on the luminescent Eu(BA)3/SiO2].

    PubMed

    Zeng, Dong-ming; Li, Yan-hua; Fu, Chang-cheng; Liu, You-nian; Shu, Wan-gen

    2007-02-01

    Rare earth organic complexes combined with inorganic compounds can enhanced thermal stability, but inorganic compounds matrix has great influence on the luminescence characteristic of rare earth organic complexes. The luminescence characteristic of organic and inorganic compound material was improved by PEG doping in the material. Eu(BA)3/SiO2 and Eu(BA)3/PEG400-SiO2 were synthesized by Sol-Gel method. The result of luminescence analysis showed that the excitation spectra and emission spectra of Eu(BA)3 accorded with those of Eu(BA)3/SiO2 and Eu(BA)3/PEG400-SiO2, but the luminescence intensity of Eu(BA)3/SiO2 was improved by PEG400-SiO2 in SiO2 gel. This was because PEG400 as a hard Lewis base, could be combined with rare earth ion and increase the luminescence intensity of Eu(BA)3. It was shown that the amount of PEG400 in Eu(BA)3/SiO2 had influence on luminescence intensity of Eu(BA)3, namely there was better luminescence intensity in Eu(BA)3/SiO2 with increment of the PEG400 addition, but when the amount of PEG400 exceeded 50 wt% of that of SiO2, the luminescence intensity of Eu(BA)3 hardly increased. When the amount of PEG400 exceed 15 wt% of that of SiO2, PEG400 had little influence on the content of water and hydroxy in the matrix, as verified by IR spectrum. The surface characteristic of SiO2 gel was investigated by atomic force microscopy (AFM).

  6. Sequestration and speciation of Eu(iii) on gamma alumina: role of temperature and contact order.

    PubMed

    Cai, Yawen; Ren, Xuemei; Lang, Yue; Liu, Zhiyong; Zong, Pengfei; Wang, Xiangke; Yang, Shitong

    2015-11-01

    The speciation, migration and transport of radionuclides in the environment are significantly influenced by their interactions with the natural minerals and humic substances therein. In view of this, the effect of temperature and contact order on the sorption behaviors of trivalent Eu(iii) in the γ-Al2O3/Eu(iii) and γ-Al2O3/HA/Eu(iii) systems was studied using batch experiments and the extended X-ray absorption fine structure spectroscopy (EXAFS) technique. The endothermic sorption behavior of Eu(iii) in the γ-Al2O3/Eu(iii) systems was induced by the hydrolysis reaction of Eu(iii) in solution and the complexation of Eu(iii) with the γ-Al2O3 surface sites. The endothermic sorption of Eu(iii) in the γ-Al2O3/HA/Eu(iii) systems was attributed to the endothermic binding of HA on γ-Al2O3 and the endothermic complexation between Eu(iii) and HA. EXAFS analysis suggested the formation of type B ternary complexes and their thermodynamic stability improves with rising temperature. The different sorption percentages under various contact orders were closely related to the binding mode of Eu(iii) on the exposed γ-Al2O3 surfaces or the γ-Al2O3/HA colloids. The findings obtained herein are important to evaluate the security of the radioactive waste repository and predict the fate of trivalent actinides (e.g., Am(iii), Cm(iii), Pu(iii), etc.) near the geological repository.

  7. Eu-doped ZnO nanowire arrays grown by electrodeposition

    NASA Astrophysics Data System (ADS)

    Lupan, O.; Pauporté, T.; Viana, B.; Aschehoug, P.; Ahmadi, M.; Cuenya, B. Roldan; Rudzevich, Y.; Lin, Y.; Chow, L.

    2013-10-01

    The preparation of efficient light emitting diodes requires active optical layers working at low voltage for light emission. Trivalent lanthanide doped wide-bandgap semiconducting oxide nanostructures are promising active materials in opto-electronic devices. In this work we report on the electrochemical deposition (ECD) of Eu-doped ZnO (ZnO:Eu) nanowire arrays on glass substrates coated with F-doped polycrystalline SnO2. The structural, chemical and optical properties of ZnO:Eu nanowires have been systematically characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and photoluminescence. XRD results suggest the substitution of Zn2+ by Eu ions in the crystalline lattice. High-resolution TEM and associated electron diffraction studies indicate an interplanar spacing of 0.52 nm which corresponds to the (0 0 0 1) crystal plane of the hexagonal ZnO, and a growth along the c-direction. The ZnO:Eu nanowires have a single crystal structure, without noticeable defects. According to EDX, SIMS and XPS studies, cationic Eu species are detected in these samples showing the incorporation of Eu into the ZnO matrix. The oxidation states of europium ions in the nanowires are determined as +3 (74%) and +2 (26%). Photoluminescence studies demonstrated red emission from the Eu-doped ZnO nanowire arrays. When Eu was incorporated during the nanowire growth, the sharp 5D0-7F2 transition of the Eu3+ ion at around 612 nm was observed. These results suggest that Eu doped ZnO nanowires could pave the way for efficient, multispectral LEDs and optical devices.

  8. Energy transfer (In3+ → Eu3+) based Polyvinyl Alcohol polymer composites for bright red luminescence

    NASA Astrophysics Data System (ADS)

    Kumar, K. Naveen; Vijayalakshmi, L.; Kim, Jong Su; Shim, Jaesool; Cho, Migyung; Kang, Misook; Gupta, Bipin Kumar

    2017-08-01

    A prominent sensitization effect of In3+ ions is observed in In3++Eu3+: PVA polymer composites under UV excitation. Consequently, it enhances the red emission performance of Eu3+ ions in PVA system. We have successfully synthesized Eu3+: PVA, In3+: PVA and In3++Eu3+: PVA polymer films by traditional solution casting method. The structural and ion-polymer interaction studies have been analyzed from XRD and FTIR spectral profiles. Eu3+ doped PVA polymer composites are exhibited a red emission at 619 nm (5D0→7F2) under 396 nm (7F0→5L6) of excitation. Upon co-doping with In3+ ions in different concentrations to the Eu3+: PVA polymer film, it exhibits predominant red emission than singly doped Eu3+: PVA under 396 nm of excitation due to energy migration from In3+ to Eu3+. Successful emission photons of In3+ ions are collectively absorbed by the Eu3+ ions which lead the improvement of red emission. Optimized sensitization concentration of the In3+ ions has been found to be 0.01 wt%. Possible energy migration phenomenon is elucidated by several fluorescent dynamics. The energy transfer process is substantiated by lifetime decay analysis and overlapped spectral studies. The Commission International de I-Eclairage chromaticity coordinates were calculated. The quantum efficiencies of the Eu3+ ions and In3+ ions in singly doped and co-doped polymer systems have been evaluated. From these results, these co-doped In3++Eu3+: PVA composite polymer films might be proposed as encouraging candidates for bright red fluorescent materials for several photonic applications.

  9. Technology and optical characterization of luminophore coordination compounds Eu(o-MBA)3Phen and NC PEPC/Eu(o-MBA)3Phen

    NASA Astrophysics Data System (ADS)

    Bordian, Olga; Verlan, Victor; Culeac, Ion; Iovu, Mihail; Zubareva, Vera

    2016-12-01

    Were obtained a new nanocomposite (NC) based on poly N-epoxy prolyl carbazol (PEPC) and the coordination compound luminophore Eu(o-MBA)3Phen, where o-MBA is o- methylbenzoic acid and Phen - phenanthroline. Nanocrystals of Eu(o-MBA)3Phen with the dimensions 50 nm were uniformly incorporated into the PEPC polymer matrix with various concentrations. The absorption spectra of coordination compounds and thin layers of NC PEPC/Eu(o-MBA)3Phen revealed 1 intensive absorption bands at 2.02 eV. Photoluminescence (PL) spectra showed an intense red luminescence at 578 - 699 nm, which is assigned to the transitions 4D0->7Fi (i= 0,1,2 3 4) in the 4f-shell of the Eu3+ ion.

  10. Intense intrashell luminescence of Eu-doped single ZnO nanowires at room temperature by implantation created Eu-Oi complexes.

    PubMed

    Geburt, Sebastian; Lorke, Michael; da Rosa, Andreia L; Frauenheim, Thomas; Röder, Robert; Voss, Tobias; Kaiser, Uwe; Heimbrodt, Wolfram; Ronning, Carsten

    2014-08-13

    Successful doping and excellent optical activation of Eu(3+) ions in ZnO nanowires were achieved by ion implantation. We identified and assigned the origin of the intra-4f luminescence of Eu(3+) ions in ZnO by first-principles calculations to Eu-Oi complexes, which are formed during the nonequilibrium ion implantation process and subsequent annealing at 700 °C in air. Our targeted defect engineering resulted in intense intrashell luminescence of single ZnO:Eu nanowires dominating the photoluminescence spectrum even at room temperature. The high intensity enabled us to study the luminescence of single ZnO nanowires in detail, their behavior as a function of excitation power, waveguiding properties, and the decay time of the transition.

  11. [Preparation and spectroscopy properties of Eu2 (CA)3 (phen)2 doped Eu3+/TiO2 nano-powders].

    PubMed

    Zhao, Si-qin; Guo, Min; Zhang, Mei; Wang, Xi-gui; Chang, Shan

    2010-08-01

    The 1% Eu3+ doped Eu3+ /TiO2 nano-powders were prepared via sol-gel method by using Eu(NO3)3 and Eu2 (CA)3 (phen)2 (CA: camphoric acid; phen: 1, 10-phenanthroline) as precursors respectively, and the samples were characterized by thermal analyses (TG-DTA), X-ray powder diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectra and fluorescence spectra for their microstructure, morphology and spectroscopy properties. The results of TG-DTA and XRD indicate that the increasing trend of particle size and the conversion temperature of crystalline phase of the as prepared samples was restrained when using organic complexes Eu2(CA)3 (phen)2 as the do pant. The particle size was decreased from 9 to 7 nm, and the name powders were still anatase TiO2 when the calcination temperature was increased up to 500 degrees C. The absorption peak at about 370 nm in UV-Vis spectra was red-shifted when doping with organic complexes Eu2 (CA)3 (phen)2, namely the doped TiO2 nano powders have the ability of visible light responding. The characteristic absorption peaks of organic complex did not appear in FTIR spectrum, indicating that the Eu3+ has little impact on the formation process of TiO2 crystal when using Eu2(CA)3 (phen)2 as precursor. The result of fluorescence spectrum indicates that the characteristic transition of Eu3+ at 578 nm (corresponding to (5)D0---(7)F0), 590 nm((5)D0-(7)F1) and 612 nm ((5)D0-(7)F2) appeared in both samples, in which the peak at 612 nm was the characteristic red transmutation peak. When doping Eu3+ with the same content, the nano-powders using Eu2 (CA)3 (phen)2 as precursor obtain higher luminescence intensity. Therefore, by using a simple approach, the authors prepared the light-emitting rare earth inorganic nano-powders with better luminescence property and high stability, and such inorganic nano-powders might have potential applications in many fields.

  12. SrAgZn and EuAgZn with KHg{sub 2}-type structure—Structure, magnetic properties, and {sup 151}Eu Mössbauer spectroscopy

    SciTech Connect

    Gerke, Birgit; Rodewald, Ute Ch.; Niehaus, Oliver; Pöttgen, Rainer

    2013-07-15

    Samples of SrAgZn and EuAgZn were synthesized by reaction of the elements in sealed tantalum crucibles. Both structures were refined on the basis of single crystal X-ray diffractometer data: KHg{sub 2}-type, Imma, a=476.7(1), b=780.9(2), c=810.1(2) pm, R{sub 1}/wR{sub 2}=0.0189/0.0119, 381 F² values for SrAg{sub 1.12}Zn{sub 0.88} and a=474.43(9), b=760.8(2), c=799.0(2) pm, R{sub 1}/wR{sub 2}=0.0226/0.0483, 370 F² values for EuAg{sub 1.17}Zn{sub 0.83} with 13 variables per refinement. Silver and zinc are randomly distributed on the Hg position and build up three-dimensional networks. EuAgZn shows ferromagnetic ordering at 29(1) K. In the temperature range from 75 to 300 K the sample shows Curie–Weiss behaviour with μ{sub eff}=7.87(1) μ{sub B}/Eu atom and θ{sub P}=37.1(1) K, indicating divalent europium. {sup 151}Eu Mössbauer spectroscopic measurements confirmed the divalent state with an isomer shift of −9.31 mm/s at 78 K. Temperature dependent {sup 151}Eu data show first magnetic hyperfine field splitting at 25 K and a saturated magnetization of 17 T at 5.2 K. The temperature dependence can be described by an S=7/2 Brillouin function. - Graphical abstract: The near neighbor coordination of the strontium and europium atoms in SrAg{sub 1.12}Zn{sub 0.88}, EuAg{sub 1.17}Zn{sub 0.83}, and EuAuZn. - Highlights: • Synthesis of new intermetallic zinc compounds SrAgZn and EuAgZn. • Ferromagnetic ordering of EuAgZn at 29 K. • Magnetic hyperfine field splitting in the {sup 151}Eu Mössbauer spectrum.

  13. Spin transistor based on pure nonlocal Andreev reflection in EuO-graphene/superconductor/EuO-graphene nanostructure

    NASA Astrophysics Data System (ADS)

    Ang, Yee Sin; Ang, Lay Kee; Zhang, Chao; Ma, Zhongshui

    In graphene-magnetic-insulator hybrid structure such as graphene-Europium-oxide, proximity induced exchange interaction opens up a spin-dependent bandgap and spin splitting in the Dirac band. We show that such band topology allows pure crossed Andreev reflection to be generated exclusively without the parasitic local Andreev reflection and elastic cotunnelling over a wide range of bias and Fermi levels. We model the charge transport in an EuO-graphene/superconductor/EuO-graphene three-terminal device and found that the pure non-local conductance exhibits rapid on/off switching characteristic with a minimal subthreshold swing of ~ 20 mV. Non-local conductance oscillation is observed when the Fermi levels in the superconducting lead is varied. The oscillatory behavior is directly related to the quasiparticle propagation in the superconducting lead and hence can be used as a tool to probe the subgap quasiparticle mode in superconducting graphene. The non-local current is 100% spin-polarized and is highly tunable in our proposed device. This opens up the possibility of highly tunable graphene-based spin transistor that operates purely in the non-local transport regime.

  14. Luminescent down-shifting layers with Eu2+ and Eu3+ doped strontium compound particles for photovoltaics

    NASA Astrophysics Data System (ADS)

    Solodovnyk, Anastasiia; Hollmann, Andre; Osvet, Andres; Forberich, Karen; Stern, Edda; Batentschuk, Miroslaw; Klupp Taylor, Robin; Brabec, Christoph J.

    2014-10-01

    In this contribution we discuss luminescent down-shifting (LDS) systems consisting of a polymer matrix filled with phosphor particles. It is an elegant approach to make a use of potentially destructive or otherwise wasted high energy photons and diminish charge carrier losses caused by thermalization in photovoltaics. Sub-micron and micron sized particles of strontium aluminate doped with Eu2+ and strontium carbonate doped with Eu3+ ions are chosen for the application due to their suitable absorption in UV spectral region. These particles exhibit strong luminescence in the visible range between 520 and 650 nm. The systems are carefully designed to meet critical optical requirements such as high transparency in the visible spectrum as well as sufficient absorption of UV light. They are coated on quartz glass substrates (20 x 20 x 1 mm) and can be easily laminated to different kinds of solar cells without any modification to well-established device fabrication processes. Optical characterization further confirms that particles of a few microns in size generate strong light scattering in layers due to the sizes slightly larger than visible light wavelengths. Dried thick layers of 20 to 100 μm are tested with CIGS and organic cells. The concept of light conversion is experimentally proven. However, optical losses cause a reduction in the overall performance of the tested devices. Possible ways to bring down the amount of light scattering and, thus, to increase optical transmission for the studied system are also addressed, and are a subject of future research.

  15. Light Emission Intensities of Luminescent Y2O3:Eu and Gd2O3:Eu Particles of Various Sizes

    PubMed Central

    Adam, Jens; Metzger, Wilhelm; Koch, Marcus; Rogin, Peter; Coenen, Toon; Atchison, Jennifer S.; König, Peter

    2017-01-01

    There is great technological interest in elucidating the effect of particle size on the luminescence efficiency of doped rare earth oxides. This study demonstrates unambiguously that there is a size effect and that it is not dependent on the calcination temperature. The Y2O3:Eu and Gd2O3:Eu particles used in this study were synthesized using wet chemistry to produce particles ranging in size between 7 nm and 326 nm and a commercially available phosphor. These particles were characterized using three excitation methods: UV light at 250 nm wavelength, electron beam at 10 kV, and X-rays generated at 100 kV. Regardless of the excitation source, it was found that with increasing particle diameter there is an increase in emitted light. Furthermore, dense particles emit more light than porous particles. These results can be explained by considering the larger surface area to volume ratio of the smallest particles and increased internal surface area of the pores found in the large particles. For the small particles, the additional surface area hosts adsorbates that lead to non-radiative recombination, and in the porous particles, the pore walls can quench fluorescence. This trend is valid across calcination temperatures and is evident when comparing particles from the same calcination temperature. PMID:28336860

  16. Selective separation of Eu{sup 3+} using polymer-enhanced ultrafiltration

    SciTech Connect

    Norton, M.V.

    1994-03-01

    A process to selectively remove {sup 241}Am from liquid radioactive waste was investigated as an actinide separation method applicable to Hanford and other waste sites. The experimental procedures involved removal of Eu, a nonradioactive surrogate for Am, from aqueous solutions at pH 5 using organic polymers in conjunction with ultrafiltration. Commercially available polyacrylic acid (60,000 MW) and Pacific Northwest Laboratory`s (PNL) synthesized E3 copolymer ({approximately}10,000 MW) were tested. Test solutions containing 10 {mu}g/mL of Eu were dosed vath each polymer at various concentrations in order to bind Eu (i.e., by complexation and/or cation exchange) for subsequent rejection by an ultrafiltration coupon. Test solutions were filtered with and without polymer to determine if enhanced Eu separation could be achieved from polymer treatment. Both polymers significantly increased Eu removal. Optimum concentrations were 20 {mu}g/mL of polyacrylic acid and 100 {mu}g/mL of E3 for 100% Eu rejection by the Amicon PM10 membrane at 55 psi. In addition to enhancement of removal, the polymers selectively bound Eu over Na, suggesting that selective separation of Eu was possible. This suggests that polymer-enhanced ultrafiltration is a potential process for separation of {sup 241}Am from Hanford tank waste, further investigation of binding agents and membranes effective under very alkaline and high ionic strength is warranted. This process also has potential applications for selective separation of toxic metals from industrial process streams.

  17. Synthesis of Gd2O3:Eu nanoplatelets for MRI and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Maalej, Nabil M.; Qurashi, Ahsanulhaq; Assadi, Achraf Amir; Maalej, Ramzi; Shaikh, Mohammed Nasiruzzaman; Ilyas, Muhammad; Gondal, Mohammad A.

    2015-05-01

    We synthesized Gd2O3 and Gd2O3 doped by europium (Eu) (2% to 10%) nanoplatelets using the polyol chemical method. The synthesized nanoplatelets were characterized by X-ray diffraction (XRD), FESEM, TEM, and EDX techniques. The optical properties of the synthesized nanoplatelets were investigated by photoluminescence spectroscopy. We also studied the magnetic resonance imaging (MRI) contrast enhancement of T1 relaxivity using 3 T MRI. The XRD for Gd2O3 revealed a cubic crystalline structure. The XRD of Gd2O3:Eu3+ nanoplatelets were highly consistent with Gd2O3 indicating the total incorporation of the Eu3+ ions in the Gd2O3 matrix. The Eu doping of Gd2O3 produced red luminescence around 612 nm corresponding to the radiative transitions from the Eu-excited state 5D0 to the 7F2. The photoluminescence was maximal at 5% Eu doping concentration. The stimulated CIE chromaticity coordinates were also calculated. Judd-Ofelt analysis was used to obtain the radiative properties of the sample from the emission spectra. The MRI contrast enhancement due to Gd2O3 was compared to DOTAREM commercial contrast agent at similar concentration of gadolinium oxide and provided similar contrast enhancement. The incorporation of Eu, however, decreased the MRI contrast due to replacement of gadolinium by Eu.

  18. Growth of EuO films on Si using Pulsed Laser Deposition

    NASA Astrophysics Data System (ADS)

    Jain, Vivek S.; Rimal, Gaurab; Tang, Jinke

    Epitaxial monolayers of europium monoxide (EuO) deposited on silicon (Si) wafers are suited for spintronic applications such as adding spin filter tunneling and spin current to Si technology, and for probing phenomena like Anomalous Hall effect and Topological Hall effect. However, the innate chemical reactivity of europium (Eu) and Si prevents a direct synthesis of EuO by pulsed laser deposition technique, without significant contamination of the EuO/Si interface and degradation of the EuO thin film. Silicon oxides (SiO2-δ) on the surface of Si substrates, partial pressure of oxygen (O2) gas and water vapors in the vacuum chamber act as contaminants. Techniques like standard wet etching process, thermal annealing, and decomposition of SiO2-δ by the bombardment of metal ions, and their effectiveness is studied using the X-Ray diffraction (XRD) system. Our goal is one-process in situ integration of spin-functional magnetic oxides seamless on Si wafers. Also the mechanism for the ferromagnetic order in oxygen-deficient europium monoxide (EuO1-x) at temperatures higher than 69K (the Curie temperature of stoichiometric EuO) remains controversial. We have investigated the magnetization of EuO1-x thin films prepared via PLD as a function of (emu) vs (K) Wyoming EPSCoR.

  19. A Smart Social Inclusion Policy for the EU: The Role of Education and Training

    ERIC Educational Resources Information Center

    Nicaise, Ides

    2012-01-01

    Whereas in 2000 the EU had heralded the knowledge-based society with as its motto "with more and better jobs and stronger social cohesion", the past decade has led to greater inequality and (at best) a status-quo in poverty. EU2020 seems to acknowledge this failure and aims to reconnect social inclusion with the knowledge-based strategy.…

  20. Observation of variable hybridized-band gaps in Eu-intercalated graphene.

    PubMed

    Sung, Sijin; Kim, Sooran; Lee, Paengro; Kim, Jingul; Ryu, Min-Tae; Park, Heemin; Kim, Kyoo; Min, Byung; Chung, Jinwook

    2017-03-27

    We report europium (Eu)-induced changes in the π-band of graphene (G) formed on 6H-SiC(0001) surface by a combined study of photoemission measurements and density functional theory (DFT) calculations. Our photoemission data reveal that Eu intercalates upon annealing at 120 °C into the region between graphene and buffer layer (BL) to form a G/Eu/BL system, where a band gap of 0.29 eV opens at room temperature. This band gap is found to increase further to 0.48 eV upon cooling down to 60 K. Our DFT calculations suggest that the increased band gap originates from the enhanced hybridization between graphene π-Eu 4f band due to the increased magnetic ordering upon cooling. These Eu atoms continue to intercalate further down below the BL to produce a bilayer graphene (G/BL/Eu) upon annealing at 300 °C. The π-band stemming from the BL then exhibits another band gap of 0.37 eV, which appears to be a gap due to the strong hybridization between the π-band of the BL and the Eu 4f band. The Eu-intercalated graphene thus illustrates an example of versatile band gaps formed under different thermal treatments, which may play a critical role for future applications in graphene-based electronics.

  1. Effect of silver ions and clusters on the luminescence properties of Eu-doped borate glasses

    SciTech Connect

    Jiao, Qing; Wang, Xi; Qiu, Jianbei; Zhou, Dacheng

    2015-12-15

    Highlights: • Ag{sup +} and Ag clusters are investigated in the borate glasses via ion exchange method. • The aggregation of silver ions to the clusters was controlled by the ion exchange concentration. • Eu{sup 3+}/Eu{sup 2+} ions emission was enhanced with the sensitization of the silver species. • Energy transfer process from Ag ions and Ag clusters to Eu ions is identified by the lifetime measurements. - Abstract: Silver ions and clusters were applied to Eu{sup 3+}-doped borate glasses via the Ag{sup +}–Na{sup +} ion exchange method. Eu{sup 3+}/Eu{sup 2+} ion luminescence enhancement was achieved after silver ion exchange. Absorption spectra showed no band at 420 nm, which indicates that silver nanoparticles can be excluded as a silver state in the glass. Silver ion aggregation into clusters during the ion exchange process may be inferred. The effect of silver ions and clusters on rare earth emissions was investigated using spectral information and lifetime measurements. Significant luminescence enhancements were observed from the energy transfer of Ag{sup +} ions and clusters to Eu{sup 3+}/Eu{sup 2+} ions, companied with the silver ions aggregated into the clusters state. The results of this research may extend the current understanding of interactions between rare-earth ions and Ag species.

  2. European Master's Program in Gerontology (EuMaG): Goals, Curriculum, and Students

    ERIC Educational Resources Information Center

    Aartsen, Marja

    2011-01-01

    The European Master's Program in Gerontology (EuMaG) started in September 2003 with support from the European Commission. The EuMaG is a modular, 2-year, part-time international training program about the aging process and its societal implications. The multidisciplinary curriculum comprises four domains of gerontology (i.e., social gerontology,…

  3. Human Resources Policies Compared: What Can the EU and the USA Learn from Each Other?

    ERIC Educational Resources Information Center

    Tome, Eduardo

    2005-01-01

    Purpose: To compare in a fruitful way the human resources (HR) policies that exist in the European Union (EU) and in the United States of America (USA). Nowadays, the world is evolving to a situation in which big economic spaces like Brazil, Russia, India, China, Japan, the EU and the USA are becoming dominant. Those spaces can learn from one…

  4. Photolumiscent properties of nanorods and nanoplates Y2O3:Eu3+.

    PubMed

    de Moura, Ana Paula; de Oliveira, Larissa Helena; Paris, Elaine Cristina; Li, Máximo Siu; Andrés, Juan; Varela, José Arana; Longo, Elson; Rosa, Ieda Lucia Viana

    2011-07-01

    Nanorods and nanoplates of Y(2)O(3):Eu(3+) powders were synthesized through the thermal decomposition of the Y(OH)(3) precursors using a microwave-hydrothermal method in a very short reaction time. These powders were analyzed by X-ray diffraction, field emission scanning electron microscopy, Fourrier transform Raman, as well as photoluminescence measurements. Based on these results, these materials presented nanoplates and nanorods morphologies. The broad emission band between 300 and 440 nm ascribed to the photoluminescence of Y(2)O(3) matrix shifts as the procedure used in the microwave-hydrothermal assisted method changes in the Y(2)O(3):Eu(3+) samples. The presence of Eu(3+) and the hydrothermal treatment time are responsible for the band shifts in Y(2)O(3):Eu(3+) powders, since in the pure Y(2)O(3) matrix this behavior was not observed. Y(2)O(3):Eu(3+) powders also show the characteristic Eu(3+) emission lines at 580, 591, 610, 651 and 695 nm, when excited at 393 nm. The most intense band at 610 nm is responsible for the Eu(3+) red emission in these materials, and the Eu(3+) lifetime for this transition presented a slight increase as the time used in the microwave-hydrothermal assisted method increases.

  5. Photo- and electroluminescence of mixed-ligand Eu(III) complexes

    NASA Astrophysics Data System (ADS)

    Eremina, N. S.; Meshkova, S. B.; Degtyarenko, K. M.; Kopylova, T. N.; Topilova, Z. M.; Gadirov, R. M.; Samsonova, L. G.

    2012-05-01

    Spectral and luminescent properties of mixed-ligand Eu(III) complexes were studied in solutions and in polyvinylcarbazole (PVC) thin films. Trends in their variations were found depending on the complex structure and excitation mode. The electroluminescence was observed in ITO/PEDOT/Eu complex:PVC/CaMg/Al devices. Their current-voltage and voltage-brightness characteristics were investigated.

  6. 78 FR 14840 - U.S.-EU High Level Regulatory Cooperation Forum-Stakeholder Session

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... BUDGET U.S.-EU High Level Regulatory Cooperation Forum--Stakeholder Session AGENCY: Office of Management... will hold a public meeting of the U.S.-EU High Level Regulatory Cooperation Forum (the ``Forum'') in...:00 a.m. and ending by 12:00 p.m. ADDRESSES: Public Meeting: As with previous Forum meetings, the...

  7. European Master's Program in Gerontology (EuMaG): Goals, Curriculum, and Students

    ERIC Educational Resources Information Center

    Aartsen, Marja

    2011-01-01

    The European Master's Program in Gerontology (EuMaG) started in September 2003 with support from the European Commission. The EuMaG is a modular, 2-year, part-time international training program about the aging process and its societal implications. The multidisciplinary curriculum comprises four domains of gerontology (i.e., social gerontology,…

  8. EU Strategies to Encourage Youth Entrepreneurship: Evidence from Higher Education in Greece

    ERIC Educational Resources Information Center

    Karanassios, Nikolaos; Pazarskis, Michail; Mitsopoulos, Konstantinos; Christodoulou, Petros

    2006-01-01

    The authors present and discuss significant aspects of youth entrepreneurship in the European Union (EU) and, especially, in higher education institutions in Greece. The structure of this paper is as follows. First, the study introduces a conceptual basis for entrepreneurship as defined in the EU and looks at entrepreneurship in the context of…

  9. Social Studies Pre-Service Teachers' Views on the EU Membership Process: A Multidimensional Evaluation

    ERIC Educational Resources Information Center

    Gençtürk, Ebru

    2015-01-01

    One of the general purposes of Social Studies is to integrate individuals with the social life by providing accurate knowledge and skills about their environment and society. As well as the role of Social Studies in raising consciousness on EU relations, Social Studies teachers' views about EU membership and the sources of these views are…

  10. NO-assisted molecular-beam epitaxial growth of nitrogen substituted EuO

    NASA Astrophysics Data System (ADS)

    Wicks, R.; Altendorf, S. G.; Caspers, C.; Kierspel, H.; Sutarto, R.; Tjeng, L. H.; Damascelli, A.

    2012-04-01

    We have investigated a method for substituting oxygen with nitrogen in EuO thin films, which is based on molecular beam epitaxy distillation with NO gas as the oxidizer. By varying the NO gas pressure, we produce crystalline, epitaxial EuO1 -xNx films with good control over the films' nitrogen concentration. In situ x-ray photoemission spectroscopy reveals that nitrogen substitution is connected to the formation Eu3+4f6 and a corresponding decrease in the number of Eu2+4f7, indicating that nitrogen is being incorporated in its 3- oxidation state. While small amounts of Eu3+ in over-oxidized Eu1-δO thin films lead to a drastic suppression of the ferromagnetism, the formation of Eu3+ in EuO1-xNx still allows the ferromagnetic phase to exist with an unaffected Tc, thus providing an ideal model system to study the interplay between the magnetic f7 (J = 7/2) and the non-magnetic f6 (J = 0) states close to the Fermi level.

  11. Thermoreversible luminescent organogels doped with Eu(TTA)3phen complex.

    PubMed

    Di Lorenzo, Maria Laura; Cocca, Mariacristina; Gentile, Gennaro; Avella, Maurizio; Gutierrez, David; Della Pirriera, Monica; Kennedy, Manus; Ahmed, Hind; Doran, John

    2013-05-15

    This manuscript details the preparation and characterization of luminescent organogels in toluene. Gels were prepared by using 12-hydroxystearic acid (12HSA) as gelator and different amounts of thenoyltrifluoroacetonato 1,10-phenanthroline europium(III) complex (Eu(TTA)3phen). The gelation properties and the thermoreversible behavior from solid-like to liquid systems were investigated by differential scanning calorimetry. At higher concentration, an interaction of Eu complex with the polar group of the gelator was revealed by DSC and FTIR analyses. The spectroscopic behavior of the complex was investigated in toluene solution and in the gel state. TEM analysis revealed that 12HSA is able to solvate the Eu diketonate complex inducing a remarkable increase in the Eu-Eu distance. The Eu(TTA)3phen in the gel state exhibits a very high emission quantum yield, Φ, which was found to be independent of Eu complex concentration, at least for the composition range analyzed. These results indicate that 12HSA organogels containing Eu(TTA)3phen are promising materials for optical applications.

  12. Draft genome sequences of seven isolates of Phytophthora ramorum EU2 from Northern Ireland

    PubMed Central

    Mata Saez, Lourdes de la; McCracken, Alistair R.; Cooke, Louise R.; O'Neill, Paul; Grant, Murray; Studholme, David J.

    2015-01-01

    Here we present draft-quality genome sequence assemblies for the oomycete Phytophthora ramorum genetic lineage EU2. We sequenced genomes of seven isolates collected in Northern Ireland between 2010 and 2012. Multiple genome sequences from P. ramorum EU2 will be valuable for identifying genetic variation within the clonal lineage that can be useful for tracking its spread. PMID:26697370

  13. Draft genome sequences of seven isolates of Phytophthora ramorum EU2 from Northern Ireland.

    PubMed

    Mata Saez, Lourdes de la; McCracken, Alistair R; Cooke, Louise R; O'Neill, Paul; Grant, Murray; Studholme, David J

    2015-12-01

    Here we present draft-quality genome sequence assemblies for the oomycete Phytophthora ramorum genetic lineage EU2. We sequenced genomes of seven isolates collected in Northern Ireland between 2010 and 2012. Multiple genome sequences from P. ramorum EU2 will be valuable for identifying genetic variation within the clonal lineage that can be useful for tracking its spread.

  14. Ping Pong: Competing Leadership for Reform in EU Higher Education 1998-2006

    ERIC Educational Resources Information Center

    Corbett, Anne

    2011-01-01

    How effective is EU cooperation in higher education? This article treats the issue as one of effectiveness in policy-making. What are the policy ideas which the EU wishes to feed into a policy domain where it has to operate largely through political cooperation and a modest degree of incentive funding? What outcomes are possible? The question is…

  15. Enhanced luminescence of Gd2O3:Eu3+ thin-film phosphors by Li doping

    NASA Astrophysics Data System (ADS)

    Yi, Soung-soo; Bae, Jong Seong; Shim, Kyoo Sung; Jeong, Jung Hyun; Park, Jung-Chul; Holloway, P. H.

    2004-01-01

    Gd2O3:Eu3+ and Li-doped Gd2O3:Eu3+ luminescent thin films have been grown on Al2O3 (0001) substrates using pulsed-laser deposition. The films grown under different deposition conditions show different microstructural and luminescent characteristics. Both cubic and monoclinic crystalline structures were observed in Gd2O3:Eu3+ films, but only the cubic crystalline structure was observed for Li-doped Gd2O3:Eu3+ films grown under certain condition. The photoluminescence (PL) brightness data obtained from Li-doped Gd2O3:Eu3+ films indicate that sapphire is a promising substrate for growth of high-quality Li-doped Gd2O3:Eu3+ thin-film red phosphor. In particular, incorporation of Li+ ions into the Gd2O3 lattice can induce a remarkable increase of PL. The highest emission intensity was observed with LiF-doped Gd1.84Li0.08Eu0.08O3, whose brightness was a factor of 2.3 larger than that from Gd2O3:Eu3+ films. This phosphor is promising for applications in flat-panel displays.

  16. Bulletin on Women and Employment in the EU. 1994-1996.

    ERIC Educational Resources Information Center

    Bulletin on Women and Employment in the EU, 1996

    1996-01-01

    These six bulletins examine various aspects of women's employment in the European Union (EU). In the first bulletin, the different positions of women in the labor markets of the individual EU member countries are demonstrated to mirror the roles of women in each country's family and welfare system. The problems of unemployment and underemployment…

  17. Low-temperature solvothermal synthesis of EuS hollow microspheres

    SciTech Connect

    Peng, Yong; Wang, Hong; Li, Peng; Fu, Yao Xing, Mingming; Jiang, Tao; Luo, Xixian

    2014-09-15

    Graphical abstract: Synthesis of EuS hollow microspheres at low-temperature via solvothermal method for the first time. - Highlights: • We adopt an improved method to synthesise the (Phen)Eu(Et{sub 2}CNS{sub 2}){sub 3} in deionized water. • We have successfully synthesised the EuS hollow microsphere at 230 °C in acetonitrile. • The price of acetonitrile is more inexpensive, so the price of preparation was reduced. - Abstract: EuS crystals are synthesized by low-temperature solvothermal decomposition of the single source precursor complex (Phen)Eu(Et{sub 2}CNS{sub 2}){sub 3} in acetonitrile. X-ray powder diffraction, scanning electron microscopy, granulocyte diameter statistical analysis, surface energy-dispersive X-ray spectroscopy analysis, and UV–vis absorption spectroscopy are used to characterize the structure and properties of the obtained EuS crystals. The results show that the formed EuS crystals are uniform hollow microspheres with a typical cubic phase structure of rock salt and the average particle size of 2.01 μm. The mechanisms for the thermal decomposition of the precursor complex and the formation of the EuS hollow microspheres are postulated based on the experimental observations and previous reports.

  18. Human Resources Policies Compared: What Can the EU and the USA Learn from Each Other?

    ERIC Educational Resources Information Center

    Tome, Eduardo

    2005-01-01

    Purpose: To compare in a fruitful way the human resources (HR) policies that exist in the European Union (EU) and in the United States of America (USA). Nowadays, the world is evolving to a situation in which big economic spaces like Brazil, Russia, India, China, Japan, the EU and the USA are becoming dominant. Those spaces can learn from one…

  19. Hollow GdPO4:Eu3+ microspheres: Luminescent properties and applications as drug carrier

    NASA Astrophysics Data System (ADS)

    Tang, Yanxia; Mei, Rui; Yang, Shaokun; Tang, Hongxia; Yin, Wenzhong; Xu, Yongchun; Gao, Yaping

    2016-04-01

    GdPO4:Eu3+ samples were synthesized by a hydrothermal process using melamine formaldehyde (MF) as template. The X-ray diffraction (XRD) patterns and the Fourier Transform Infrared (FTIR) spectrum suggested that GdPO4:Eu3+ has a hexagonal phase. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images showed that the obtained GdPO4:Eu3+ are hollow microspheres with diameters in the range of 1-1.5 μm. Under the excitation at 245 nm, hexagonal GdPO4:Eu3+ hollow microspheres showed emission bands originating from the 5D0 → 7FJ (J = 1, 2, 3 and 4) transitions of Eu3+. The drug release properties of hexagonal GdPO4:Eu3+ hollow microspheres were exhibited by the doxorubicin hydrochloride (DOX) release test. The biocompatibility of hexagonal GdPO4:Eu3+ hollow microsphere was tested by the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results indicated that hollow GdPO4:Eu3+ microspheres have potential applications in biomedicine fields.

  20. Synthesis of Gd2O3:Eu nanoplatelets for MRI and fluorescence imaging.

    PubMed

    Maalej, Nabil M; Qurashi, Ahsanulhaq; Assadi, Achraf Amir; Maalej, Ramzi; Shaikh, Mohammed Nasiruzzaman; Ilyas, Muhammad; Gondal, Mohammad A

    2015-01-01

    We synthesized Gd2O3 and Gd2O3 doped by europium (Eu) (2% to 10%) nanoplatelets using the polyol chemical method. The synthesized nanoplatelets were characterized by X-ray diffraction (XRD), FESEM, TEM, and EDX techniques. The optical properties of the synthesized nanoplatelets were investigated by photoluminescence spectroscopy. We also studied the magnetic resonance imaging (MRI) contrast enhancement of T1 relaxivity using 3 T MRI. The XRD for Gd2O3 revealed a cubic crystalline structure. The XRD of Gd2O3:Eu(3+) nanoplatelets were highly consistent with Gd2O3 indicating the total incorporation of the Eu(3+) ions in the Gd2O3 matrix. The Eu doping of Gd2O3 produced red luminescence around 612 nm corresponding to the radiative transitions from the Eu-excited state (5)D0 to the (7)F2. The photoluminescence was maximal at 5% Eu doping concentration. The stimulated CIE chromaticity coordinates were also calculated. Judd-Ofelt analysis was used to obtain the radiative properties of the sample from the emission spectra. The MRI contrast enhancement due to Gd2O3 was compared to DOTAREM commercial contrast agent at similar concentration of gadolinium oxide and provided similar contrast enhancement. The incorporation of Eu, however, decreased the MRI contrast due to replacement of gadolinium by Eu.

  1. Eu/Tb codoped spindle-shaped fluorinated hydroxyapatite nanoparticles for dual-color cell imaging.

    PubMed

    Ma, Baojin; Zhang, Shan; Qiu, Jichuan; Li, Jianhua; Sang, Yuanhua; Xia, Haibing; Jiang, Huaidong; Claverie, Jerome; Liu, Hong

    2016-06-02

    Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500-580 nm) can be decreased to the benefit of the emission in the red region (580-720 nm), thus reaching a balanced dual color emission. Using MC3T3-E1 cells co-cultured with Eu/Tb codoped FAp nanoparticles, it is observed that the nanoparticles are cytocompatible even at a concentration as high as 800 μg ml(-1). The Eu/Tb codoped FAp nanoparticles are located in the cytoplasm and can be monitored by dual color-green and red imaging with a single excitation light at 488 nm. At a concentration of 200 μg ml(-1), the cytoplasm is saturated in 8 hours, and Eu/Tb codoped FAp nanoparticles retain their fluorescence for at least 3 days. The cytocompatible Eu/Tb codoped FAp nanoparticles with unique dual color emission will be of great use for cell and tissue imaging.

  2. [Influence of Bi3+ doping on properties of CaMoO4 : Eu3+ phosphors].

    PubMed

    Zhang, Qing-Xia; Long, Dan-Dan; Zhang, Fan; Qi, Xiao-Hua; Zhang, Heng; Yan, Jing-Hui; Zou, Ming-Qiang

    2013-07-01

    Europium doped CaMoO4 and bismuth co-doped CaMoO4 : Eu3+ phosphors were prepared via microemulsion-hydrothermal method. The structure, morphology and luminescence properties of samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectroscopy, respectively. The XRD patterns of as-prepared samples were in agreement with the PDF # 29-0351 of CaMoO4, which indicated that the phosphor possessed tetragonal crystal structure. SEM images showed that the samples were basically flake in shape and their average size was 1.5-2.5 microm. The critical molar concentration of activator (Eu3+) in CaMoO4 : Eu3+ was 5%, and the predominant peak of CaMoO4 : Eu3+ located at 616 nm, corresponding to the 5D0 -->7 F2 electronic dipole transition of Eu3+. The photoluminescence color can be tuned from orange-yellow (0.514, 0.537) to white (0.339, 0.333) by adjusting the doping concentrations of Eu3+ ions. To enhance the red emission intensity of Eu3+, Bi3+ was used to co-dope CaMoO4 : Eu3+ as sensitizers. When the concentration of Bi3+ is 3%, luminescence intensity was maximum. The chromaticity coordinates (CIE) varied from orange (0.497, 0.347) to red (0.585, 0.349) with increasing the content of Bi3+.

  3. Dose enhancing behavior of hydrothermally grown Eu-doped SnO2 nanoparticles

    NASA Astrophysics Data System (ADS)

    Sánchez Zeferino, R.; Pal, U.; Meléndrez, R.; Durán-Muñoz, H. A.; Barboza Flores, M.

    2013-02-01

    Hydrothermally grown SnO2 and SnO2:Eu nanoparticles of 4-11 nm size range were analyzed by photoluminescence (PL) and therrmoluminescence (TL) spectroscopy to study the effect of Eu-doping on their emission behaviors. It has been observed that most of the incorporated Eu3+ ions remain at the interstitial sites of SnO2 lattice. High Eu-contents in the nanoparticles generate lattice deformation, formation of Eu3+/Eu0 clusters at interstitial sites, or segregation to their surfaces. Formation of Eu clusters at interstitial sites enhances electronic defect density in the crystal lattice, reorganizes carrier trapping centers, and modifies their activation energies. Room temperature PL emission and beta-irradiated TL dose response of SnO2 nanoparticles enhance significantly when doped with 0.5 and 1.0 mol. % nominal of Eu3+, respectively, opening up their possibilities of applications in bio-imaging and radiation therapy. Possible mechanisms of enhanced PL and TL responses of the samples have been discussed.

  4. A Smart Social Inclusion Policy for the EU: The Role of Education and Training

    ERIC Educational Resources Information Center

    Nicaise, Ides

    2012-01-01

    Whereas in 2000 the EU had heralded the knowledge-based society with as its motto "with more and better jobs and stronger social cohesion", the past decade has led to greater inequality and (at best) a status-quo in poverty. EU2020 seems to acknowledge this failure and aims to reconnect social inclusion with the knowledge-based strategy.…

  5. Social Studies Pre-Service Teachers' Views on the EU Membership Process: A Multidimensional Evaluation

    ERIC Educational Resources Information Center

    Gençtürk, Ebru

    2015-01-01

    One of the general purposes of Social Studies is to integrate individuals with the social life by providing accurate knowledge and skills about their environment and society. As well as the role of Social Studies in raising consciousness on EU relations, Social Studies teachers' views about EU membership and the sources of these views are…

  6. Ping Pong: Competing Leadership for Reform in EU Higher Education 1998-2006

    ERIC Educational Resources Information Center

    Corbett, Anne

    2011-01-01

    How effective is EU cooperation in higher education? This article treats the issue as one of effectiveness in policy-making. What are the policy ideas which the EU wishes to feed into a policy domain where it has to operate largely through political cooperation and a modest degree of incentive funding? What outcomes are possible? The question is…

  7. Diffusion and reaction of H2 gas for reducing Eu3+ ions in glasses

    NASA Astrophysics Data System (ADS)

    Nogami, Masayuki; Quang, Vu Xuan; Nonaka, Takamasa; Shimizu, Tadashi; Ohki, Shinobu; Deguchi, Kenzo

    2017-06-01

    We have recently developed new Eu2+-doped Na2O-Al2O3-SiO2 glasses by heating precursors in H2 gas, in which Al3+ ions play an important role in reducing Eu3+ to Eu2+. However, the pathway by which the Eu3+ ions are reduced was not established. To address this question, the structural changes involving Al3+ and Eu3+ ions have been elucidated from Magic-Angle Spinning Nuclear Magnetic Resonance (MAS NMR) in solid state and X-ray absorption fine-structure spectroscopies. In the glasses with Al/Na >1, the Al3+ ions form AlO4 units without incorporating Na+ ions for charge compensation, and the Eu3+ ions are coordinated by a network structure comprising AlO4 and SiO4. When heated in H2 gas, the H2 gas molecules diffuse and react with the Eu3+ ions, reducing them to Eu2+ and forming O-H bonds. The diffusion rate of H2 molecules was analyzed from the formation process of O-H bonds; 3.37×10-12 m2/sec at 700 °C and 39.5 kJ/mol for diffusion coefficient and activation energy, respectively.

  8. The Integration of Immigrants Into the Labour Markets of the EU. IAB Labour Market Research Topics.

    ERIC Educational Resources Information Center

    Werner, Heinz

    Integration of foreign workers into European Union (EU) labor markets was evaluated. Three indicators of labor market integration were analyzed: unemployment rate, employment rate, and self- employment rate. Results were drawn from the Labor Force Survey data compiled by Eurostat. Findings indicated that, in all EU countries, the unemployment rate…

  9. Pyrolytic cavitation, selective adsorption and molecular recognition of a porous Eu(III) MOF.

    PubMed

    Liao, Wei-Ming; Shi, Hua-Tian; Shi, Xu-Hua; Yin, Ye-Gao

    2014-11-07

    A channel-equipped metal-organic framework (1-pyr), resulting from the pyrolysis of [(CH3)2NH2]@[Eu2L3(HCOO)] (1) (L(2-) = isophthalate), showed the preferable absorption of CO2 and the Eu(III)-based emission quenched by aromatics.

  10. Eu doping in multiferroic BiFeO3 ceramics studied by Mossbauer and EXAFS spectroscopy.

    PubMed

    Kothari, Deepti; Raghavendra Reddy, V; Gupta, Ajay; Meneghini, Carlo; Aquilanti, Giuliana

    2010-09-08

    Bismuth ferrite ceramics (BiFeO(3)) are multifunctional materials classified as multiferroics for their special magnetic and electric properties that can be modified by substitutional doping at the Bi and/or Fe sites. Understanding the relation between magnetoelectric response and structural/electronic modification upon doping is a relevant issue. In this work, the structure of Eu-doped multiferroic systems (Bi(1-x)Eu(x)FeO(3), x = 0, 0.5, 0.1, 0.15) as well as the valence state of Fe and Eu ions have been investigated combining Mossbauer and x-ray absorption fine structure (XAFS) spectroscopy techniques. The Eu(3+) doping at the Bi site results in better magnetic properties. High temperature (57)Fe Mossbauer data and Fe K-edge XAFS results show that FeO(6) octahedron distortions reduce with Eu(3+) doping. It is conclusively shown that the observed magnetic properties in BiFeO(3) with chemical substitution (Eu) are mainly due to the structural distortions and not due to Fe multiple valence. (151)Eu Mossbauer measurements show that the Eu(3+)(Bi(3+)) site is magnetically inactive in BiFeO(3).

  11. Formation of nanostructures in Eu3+ doped glass-ceramics: an XAS study.

    PubMed

    Pellicer-Porres, J; Segura, A; Martínez-Criado, G; Rodríguez-Mendoza, U R; Lavín, V

    2013-01-16

    We describe the results of x-ray absorption experiments carried out to deduce structural and chemical information in Eu(3+) doped, transparent, oxyfluoride glass and nanostructured glass-ceramic samples. The spectra were measured at the Pb and Eu-L(III) edges. The Eu environment in the glass samples is observed to be similar to that of EuF(3). Complementary x-ray diffraction experiments show that thermal annealing creates β-PbF(2) type nanocrystals. X-ray absorption indicates that Eu ions act as seeds in the nanocrystal formation. There is evidence of interstitial fluorine atoms around Eu ions as well as Eu dimers. X-ray absorption at the Pb-L(III) edge shows that after the thermal treatment most lead atoms form a PbO amorphous phase and that only 10% of the lead atoms remain available to form β-PbF(2) type nanocrystals. Both x-ray diffraction and absorption point to a high Eu content in the nanocrystals. Our study suggests new approaches to the oxyfluoride glass-ceramic synthesis in order to further improve their properties.

  12. Quantification of pesticides used in agriculture in the EU-27

    NASA Astrophysics Data System (ADS)

    Wagner, Susanne; Fantke, Peter; Theloke, Jochen; Friedrich, Rainer

    2010-05-01

    Pesticides have become relatively ubiquitous pollutants. They may affect non-targeted organisms and can be found as contaminants in agricultural soils, groundwater, rivers, lakes and in the food chain (Margni et al., 2002; Hamilton & Crossley, 2004; Arias-Estévez et al., 2008). As "it has been common knowledge that many pesticides cause harm to the environment and to human health" (Pretty & Waibel, 2005), it is essential to account for a quantitative assessment of impacts of current agricultural practice at the European scale. Therefore, inventory data sets of applications and related emissions of the most relevant active substances are necessary. A review of publicly available data sets evidenced that data on consumption of active substances and releases into the environment for EU member states are of low quality or lacking entirely. Either only few substances are covered (e.g. EPER, E-PRTR) or data are highly aggregated in terms of total amount of active substances. Sales or consumption data are differentiated by target organisms and crop types (Eurostat) or by chemical classes (FAOSTAT, OECD.StatExtracts). In Germany, sales data categorised into target organisms and chemical classes are available. To our knowledge, Denmark and the United Kingdom are the only European countries providing application rates for specific active substances and crops. As a basis for analysing the relation between source, environmental fate and sink of pesticides and for considering the importance of crop-specific properties on the fate of pesticides (Trapp and Kulhanek, 2006), crop-specific emission inventories for individual active substances are required. Thus, the aim of our work was to develop a crop-specific inventory for active substances currently used in agriculture in the EU-27. Based on Eurostat (2007), the five most important active substances applied to the crop categories of cereals, maize, oilseeds, potatoes, sugar-beets, grapes and vine, fruit trees and vegetables

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

    SciTech Connect

    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 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 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.

  14. Luminescence properties of europium ions-doped yttrium silicate (Y2SiO5:Eu3+) nanocrystalline phosphors: effect of Eu3+ ion concentration and thermal annealing.

    PubMed

    Ko, Yeong Hwan; Lee, Soo Hyun; Yu, Jae Su

    2013-05-01

    The trivalent europium ions-doped yttrium silicate (Y2SiO5:Eu3+) nanocrystalline phosphors were synthesized via a sol-gel method, followed by post thermal annealing. The effects of thermal annealing temperature and doping concentration on the structural and luminescent properties of Y2SiO5:Eu3+ nanocrystalline phosphors were systematically investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence measurements. The nanocrystalline phosphors with a high crystallinity were obtained at an annealing temperature of 1300 degrees C. The luminescent spectra were affected strongly by the Eu3+ ion concentration and annealing temperature. The Eu3+ ion concentration was optimized at 5 mol%, exhibiting excellent red emission (-612 nm) corresponding to the 5D0 --> 7F2 transition of Eu3+ ions at the excitation wavelengths of 262 and 396 nm. For the optimized Y2SiO5:Eu3+ nanocrystalline phosphors, the lifetimes were also estimated from the decay curves under the ultraviolet excitations.

  15. (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8]/CuPc two-component bilayer heterojunction-based organic transistors with high ambipolar performance.

    PubMed

    Gao, Dameng; Zhang, Xia; Kong, Xia; Chen, Yanli; Jiang, Jianzhuang

    2015-02-04

    Organic thin film transistor (OTFT) devices fabricated by the solution-based QLS technique from a mixed (phthalocyaninato)(porphyrinato) europium complex (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] exhibit air-stable ambipolar performance with mobilities of 6.0 × 10(-5) cm(2) V(-1) s(-)1 for holes and 1.4 × 10(-4) cm(2) V(-1) s(-1) for electrons, respectively. In good contrast, the two-component bilayer heterojunction thin film devices constructed by directly growing (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] on vacuum deposited (VCD) CuPc film using solution based QLS method were revealed to show unprecedented ambipolar performance with carrier mobilities of 0.16 cm(2) V(-1) s(-1) for holes and 0.30 cm(2) V(-1) s(-1) for electrons. In addition to the intrinsic role of p-type organic semiconductor, the VCD CuPc film on the substrate also acts as a good template that induces significant improvement over the molecular ordering of triple-decker compound in the film. In particular, it results in the change in the aggregation mode of (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] from J-type in the single-layer film to H-type in the bilayer film according to the UV-vis, XRD, and AFM observations.

  16. TAXONOMIC REVISIONS OF MORPHOLOGICALLY SIMILAR SPECIES FROM TWO EUGLENOID GENERA: EUGLENA (E. GRANULATA AND E. VELATA) AND EUGLENARIA (EU. ANABAENA, EU. CAUDATA, AND EU. CLAVATA)(1).

    PubMed

    Karnkowska-Ishikawa, Anna; Milanowski, Rafał; Triemer, Richard E; Zakryś, Bożena

    2012-06-01

    The establishment of epitypes (together with the emended diagnoses) for three species of Euglenaria Karnkowska, E. W. Linton et Kwiatowski [Eu. anabaena (Mainx) Karnkowska et E. W. Linton; Eu. caudata (Hübner) Karnkowska et E. W. Linton; and Eu. clavata (Skuja) Karnkowska et E. W. Linton] and two species of Euglena Ehrenberg [E. granulata (Klebs) Schmitz and E. velata Klebs] was achieved due to literature studies, verification of morphological diagnostic features (cell size, cell shape, number of chloroplasts, the presence of mucocysts), as well as molecular characters (SSU rDNA). Now all these species are easy to identify and distinguish, despite their high morphological similarity, that is, spindle-shaped (or cylindrically spindle-shaped) cells and parietal, lobed chloroplasts with a single pyrenoid, accompanied by bilateral paramylon caps located on both sides of the chloroplast. E. granulata is the only species in this group that has spherical mucocysts. E. velata is distinguished by the largest cells (90-150 μm) and has the highest number of chloroplasts (>30). Eu. anabaena has the fewest chloroplasts (usually 3-6), and its cells are always (whether the organism is swimming or not) spindle-shaped or cylindrically spindle-shaped, in contrast to the cells of Eu. clavata, which are club-shaped (clavate) while swimming and only after stopping change to resemble the shape of a spindle or a cylindrical spindle; Eu. clavata has numerous chloroplasts (15-20). Eu. caudata is characterized by asymmetrical spindle-shaped (fusiform) cells, that is, with an elongated rear section and a shorter front section; the number of chloroplasts normally ranges from 7 to 15.

  17. Co-precipitation synthesis of Y2O2SO4:Eu3+ nanophosphor and comparison of photoluminescence properties with Y2O3:Eu3+ and Y2O2S:Eu3+ nanophosphors

    NASA Astrophysics Data System (ADS)

    Lian, Jingbao; Qin, Hua; Liang, Ping; Liu, Feng

    2015-10-01

    Eu3+ ions activated yttrium oxysulfate (Y2O2SO4:Eu3+) nanophosphor has been successfully synthesized by a co-precipitation method from commercially available Y(NO3)3·6H2O, Eu(NO3)3·6H2O, (NH4)2SO4 and NH3·H2O as the starting materials. Detailed characterizations of the synthetic products were obtained by differential thermal analysis, thermogravimetry and derivative thermogravimetry (DTA-TG-DTG), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The results revealed that the precursor was composed of amorphous yttrium hydroxide sulfate when (NH4)2SO4 was introduced in the reaction system. Moreover, the precursor could be converted into pure Y2O2SO4 phase by calcining at 800 °C for 2 h in air and pure Y2O2S phase could be obtained by calcining Y2O2SO4 at 800 °C for 1 h in hydrogen atmosphere. The as-synthesized Y2O2SO4 phosphor particles are quasi-spherical in shape, slight aggregation and about 20-30 nm in size. PL spectra of the Y2O2SO4:Eu3+ nanophosphor under 270 nm ultraviolet (UV) light excitation show a red emission at 620 nm as the most prominent peak, which attributes to the 5D0→7F2 transition of Eu3+ ions. The quenching concentration of Eu3+ ions was 5 mol%, and its corresponding fluorescence lifetime was 1.49 ms according to the linear fitting result. Furthermore, the Y2O3 nanophosphor was synthesized by similar reaction and comparison of PL properties among three kinds of Eu3+ activated nanophosphors was also systematically discussed.

  18. Photoluminescence investigations of Y2O3: Eu phosphor co-doped with Ca

    NASA Astrophysics Data System (ADS)

    Nair, Ramya G.; Nigam, Sandeep; Sudarsan, V.; Vatsa, R. K.

    2017-05-01

    Y2O3:Eu3+ and Ca-doped Y2O3:Eu3+ luminescent particles have been synthesized via poly-ol method and subsequent annealing at 800°C. From powder X-ray diffraction pattern it is confirmed that Ca2+ ion gets incorporated into Y2O3 lattice. Photoluminescence properties of these samples are studied by luminescence excitation and emission spectra, decay curves, calculated Judd-Oflet parameters and quantum efficiency. The phosphor shows characteristic 5D0→7F1 (J = 1, 2, 3, 4) transition for Eu3+ corresponding to nearly reddish-orange color (CIE color coordinates x= 0.65, y = 0.34). Ca2+ ion doping effectively augments the Eu3+ lifetimes and quantum efficiency of Y2O3:Eu3+.

  19. Luminescence properties of Eu3+-doped Lanthanum gadolinium hafnates transparent ceramics

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjuan; Zhou, Guohong; Zhang, Jian; Qin, Xianpeng; Wang, Shiwei

    2017-09-01

    Eu3+-doped Lanthanum gadolinium hafnates (La0.8Gd1.2Hf2O7) transparent ceramics with different Eu3+ concentration were fabricated by vacuum sintering. XRD results showed all the ceramics are cubic pyrochlore structure. The effects of annealing process on in-line transmittance and luminescence behavior of the Eu3+-doped La0.8Gd1.2Hf2O7 transparent ceramics were investigated. Before annealing, the in-line transmittance of the ceramics was low and the luminescence intensity was weak. As Eu3+ doping content increased, the transmittance as well as the luminescence intensity decreased. This was ascribed to oxygen vacancy and other defects in the ceramics resulted from the vacuum sintering. After annealing, the transmittance and luminescence intensity were raised, indicating the elimination of oxygen vacancy. Moreover, with the increase of Eu3+ doping content from 1 at% to 10 at%, the luminescence intensity increased without concentration quenching.

  20. Diffused phase transition of Ba1- x Eu x TiO3 ceramics

    NASA Astrophysics Data System (ADS)

    Jun, Byeong-Eog; Choi, Byung Chun; Jeong, Jung Hyun; Moon, Byung Kee

    2016-06-01

    By applying the sol-gel method, we fabricated Ba1- x Eu x TiO3 (BET) ceramics as a single peroveskite phase in the composition range of x = 0 ~ 0.20. The BET ceramics displayed a ferroelectric phase transition temperature that changed from 120 °C to 80 °C, and exhibited the coexistance of the tetragonal, and cubic structures as the Eu composition was increased. They also displayed anomalous dielectric behaviors related to structural relaxation in the temperature range from 200 °C to 600 °C. We considered the Arrhenius temperature dependence of the dielectric relaxation time by using the electric modulus formalism. The characteristic activation energy was thought to be related with the substitution of Eu (Eu2+, Eu3+) ions for Ba2+ or Ti4+ ions in the perovskite structure.

  1. A neutron scintillator based on transparent nanocrystalline CaF{sub 2}:Eu glass ceramic

    SciTech Connect

    Struebing, Christian; Kang, Zhitao; Chong, JooYun; Wagner, Brent; Lee, Gyuhyon; Ding, Yong; Zavala, Martin; Erickson, Anna; Wang, Cai-Lin; Diawara, Yacouba; Engels, Ralf

    2016-04-11

    There are no efficient Eu{sup 2+} doped glass neutron scintillators reported due to low doping concentrations of Eu{sup 2+} and the amorphous nature of the glass matrix. In this work, an efficient CaF{sub 2}:Eu glass ceramic neutron scintillator was prepared by forming CaF{sub 2}:Eu nanocrystals in a {sup 6}Li-containing glass matrix. Through appropriate thermal treatments, the scintillation light yield of the transparent glass ceramic was increased by a factor of at least 46 compared to the as-cast amorphous glass. This improvement was attributed to more efficient energy transfer from the CaF{sub 2} crystals to the Eu{sup 2+} emitting centers. Further light yield improvement is expected if the refractive index of the glass matrix can be matched to the CaF{sub 2} crystal.

  2. Y2O3:Eu nanocrystals as biomarkers prepared by a microwave hydrothermal method

    NASA Astrophysics Data System (ADS)

    Kaszewski, Jarosław; Godlewski, Michał M.; Witkowski, Bartłomiej S.; Słońska, Anna; Wolska-Kornio, Ewelina; Wachnicki, Łukasz; Przybylińska, Hanka; Kozankiewicz, Bolesław; Szal, Anna; Domino, Małgorzata A.; Mijowska, Ewa; Godlewski, Marek

    2016-09-01

    Microwave hydrothermal growth of Y2O3 crystallites results in needle-shaped aggregates of μm length. Thermal treatment has little influence on the material microstructure, but significant impact on the nanometric level. Nanoparticles doped with europium show an intense red luminescence, related to the 5D0 → 7F2 transition of Eu3+ ions. The luminescence intensity increases with the calcination temperature and is accompanied by increasing size of Y2O3:Eu crystallites. EPR studies show the absence of Eu2+ related signals in the material. Y2O3:Eu nanoparticles crystallized via a microwave hydrothermal method were employed as luminescent biomarkers in mice. The initial tests confirmed their applicability as biological markers. Persorption of the Y2O3:Eu nanoparticles after IG in the adult mouse duodenum, brain and liver is reported.

  3. Estimation of Eu3+ in bulk uranium by ligand sensitized fluorescence in dimethyl sulphoxide

    NASA Astrophysics Data System (ADS)

    Maji, S.; Kumar, Satendra; Sankaran, K.

    2014-12-01

    Ligand sensitized fluorescence of europium ion using thenoyltrifluoroacetone (TTA) as a sensitizing ligand and dimethyl sulphoxide (DMSO) as a solvent is studied for the first time. TTA ligand enhances the fluorescence of Eu3+ by a factor of 40000 in DMSO. Linearity is obtained for a concentration range of 0.076-7.6 ng/mL of Eu3+ with a detection limit of 7.6 pg/mL. The quenching of Eu3+-TTA fluorescence by uranium matrix was studied in different solvents and found to be less in DMSO. Consequently, estimation of Eu3+ in a large excess of uranium becomes a possibility without the need to separate uranium from the solution, which has been demonstrated in this paper. Satisfactory results are obtained when Eu3+ is present at a concentration of 0.6 μg/g in uranium.

  4. Growth and optical properties of partially transparent Eu doped CaF{sub 2} ceramic

    SciTech Connect

    Ghosh, Manoranjan Sen, Shashwati Pitale, S. S. Goutam, U. K. Shinde, Seema Patra, G. D. Gadkari, S. C.

    2014-04-24

    Partially transparent ceramic of 2 at.% Eu doped CaF{sub 2} have been grown preferentially towards [111] direction. For this purpose, Eu doped CaF{sub 2} nanoparticles (size∼12 nm) obtained by a low temperature solution growth method has been pressed at 1000°C under vacuum. The preferentially grown ceramic shows 15% transparency within the visible range of spectrum. As confirmed by the X-ray diffraction result, the hot pressed ceramic exhibits reduced lattice volume than the nanopowder. It indicates Eu{sup 3+} as the dominant substituting ions at the Ca{sup 2+} sites of CaF{sub 2} lattice in the hot pressed ceramic material. It is corroborated by the photoluminescence results of hot pressed ceramic which shows strong red emission corresponding to Eu{sup 3+} sites. However, photoluminescence of nanopowder exhibits intense peak in the blue region of the spectrum which is characteristics of Eu2+ sites.

  5. Photoluminescence and energy transfer process in Gd2O3:Eu3+, Tb3+

    NASA Astrophysics Data System (ADS)

    Selvalakshmi, T.; Bose, A. Chandra

    2016-05-01

    Variation in photoluminescence (PL) properties of Eu3+ and Tb3+ as a function of co-dopant (Tb3+) concentration are studied for Gd2-x-yO3: Eu3+x Tb3+y (x = 0.02, y = 0.01, 0.03, 0.05). The crystal structure analysis is carried out by X-ray Diffraction (XRD). Absence of addition peaks corresponding europium or terbium phase confirms the phase purity. Diffuse reflectance spectroscopy (DRS) reveals the absorption peaks corresponding to host matrix, Eu3+ and Tb3+. The bandgap calculated from Kubelka - Munk function is also reported. PL spectra are recorded at the excitation wavelength of 307 nm and the emission peak corresponding to Eu3+ confirms the energy transfer from Tb3+ to Eu3+. The agglomeration of particles acts as quenching centres for energy transfer at higher concentrations.

  6. Estimation of Eu(3+) in bulk uranium by ligand sensitized fluorescence in dimethyl sulphoxide.

    PubMed

    Maji, S; Kumar, Satendra; Sankaran, K

    2014-12-10

    Ligand sensitized fluorescence of europium ion using thenoyltrifluoroacetone (TTA) as a sensitizing ligand and dimethyl sulphoxide (DMSO) as a solvent is studied for the first time. TTA ligand enhances the fluorescence of Eu(3+) by a factor of 40000 in DMSO. Linearity is obtained for a concentration range of 0.076-7.6ng/mL of Eu(3+) with a detection limit of 7.6pg/mL. The quenching of Eu(3+)-TTA fluorescence by uranium matrix was studied in different solvents and found to be less in DMSO. Consequently, estimation of Eu(3+) in a large excess of uranium becomes a possibility without the need to separate uranium from the solution, which has been demonstrated in this paper. Satisfactory results are obtained when Eu(3+) is present at a concentration of 0.6μg/g in uranium.

  7. Mesoporous hybrids containing Eu 3+ complexes covalently bonded to SBA-15 functionalized: Assembly, characterization and photoluminescence

    NASA Astrophysics Data System (ADS)

    Li Kong, Li; Yan, Bing; Li, Ying

    2009-07-01

    A novel series of luminescent mesoporous organic-inorganic hybrid materials has been prepared by linking Eu 3+ complexes to the functionalized ordered mesoporous SBA-15 which was synthesis by a co-condensation process of 1,3-diphenyl-1,3-propanepione (DBM) modified by the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TEPIC), tetraethoxysilane (TEOS), Pluronic P123 surfactant as a template. It was demonstrated that the efficient intramolecular energy transfer in the mesoporous material Eu(DBMSi-SBA-15) 3phen mainly occurred between the modified DBM (named as DBM-Si) and the central Eu 3+ ion. So the Eu(DBMSi-SBA-15) 3phen showed characteristic emission of Eu 3+ ion under UV irradiation with higher luminescence quantum efficiency. Moreover, the mesoporous hybrid materials exhibited excellent thermal stability as the lanthanide complex was covalently bonded to the mesoporous matrix.

  8. [Synthesis of SiO2 coated Eu(TTA)3phen and study on its fluorescent property].

    PubMed

    Tao, Dong-liang; Cui, Yu-min; Qiao, Rui; Xu, Yi-zhuang; Wu, Jin-guan

    2011-03-01

    New-style fluorescent material of SiO2/Eu(TTA)3 phen was synthesized by the method of dispersing Eu(TTA)3 phen in isopropanol and hydrolyzing TEOS. Fluorescence spectra showed that the emission intensities of SiO2/Eu(TTA)3 phen were much more stronger than that of Eu(TTA)3 phen by more than two times. At the same time, the peak at 617.4 nm became very sharp, which could not be observed for Eu(TTA)3 phen. This indicated that the structure of Eu(TTA)3 phen became more rigid after coated by SiO2. Thus, the emission intensity was enhanced largely. Life-time of SiOz/Eu(TTA)3 phen decreasing just confirmed the rigidity of SiO2/Eu(TTA)3 phen.

  9. A Eu(II)-Containing Cryptate as a Redox Sensor in Magnetic Resonance Imaging of Living Tissue.

    PubMed

    Ekanger, Levi A; Polin, Lisa A; Shen, Yimin; Haacke, E Mark; Martin, Philip D; Allen, Matthew J

    2015-11-23

    The Eu(II) ion rivals Gd(III) in its ability to enhance contrast in magnetic resonance imaging. However, all reported Eu(II)-based complexes have been studied in vitro largely because the tendency of Eu(II) to oxidize to Eu(III) has been viewed as a major obstacle to in vivo imaging. Herein, we present solid- and solution-phase characterization of a Eu(II)-containing cryptate and the first in vivo use of Eu(II) to provide contrast enhancement. The results indicate that between one and two water molecules are coordinated to the Eu(II) core upon dissolution. We also demonstrate that Eu(II)-based contrast enhancement can be observed for hours in a mouse.

  10. [A novel red phosphor (La3PO7:Eu3+) prepared by solid state method].

    PubMed

    Jin, Ye; Qin, Wei-ping; Zhang, Ji-sen; Wang, Yan; Cao, Chun-yan; Zhang, Ji-shuang; Ren, Xin-guang

    2008-12-01

    Novel red phosphor, Eu3+ -doped oxyphosphate (La3 PO7:Eu3+), was synthesized by a solid state method under high temperature. All the starting materials were analytical grade. La2O3, EuO3 and (NH4)2HPO4 weighed in appropriated molar ratios and ground in an agate mortar. Then the powder was treated under 1000 degrees C. The crystal phase of La3PO7:Eu3+ was investigated by X-ray diffraction (XRD) using a Cu target radiation resource (lamda = 1.54078 ?) and exhibited prominent peaks accordant with JCPDS standard card (33-0720) of La3PO7 in monoclinic phase. Emission and excitation spectra of La3PO7:Eu3+ were recorded at room temperature using a fluorescence spectrometer (Hitachi F-4500). Under 254 nm excitation, intense red fluorescence was observed from La3PO7:Eu3+, which was assigned to the (5)D0-->(7)F2 transition of Eu3+ ions. The intensity of the (5)D0-->(7)F2 transition is stronger than that of the (5)D0-->(7)F1 transition, showing that the Eu3+ ions were in the non-centrosym-metric sites in La3PO7. The CommissionIn-ternational DeL" Eclairage (CIE) coordinate of La3PO7:Eu3+ is (0.63,0.37) in the red area of CIE1931 XY chromaticity coordinate graph and close to that of Y2o3:Eu3+, but the cost of La3PO7 host is lower. This novel material may have potential applications in plasma display panels and Hg-free fluorescent lamps in the future.

  11. Eu(2)(+) -induced enhancement of defect luminescence of ZnS.

    PubMed

    Xiao-Bo, Zhang; Fu-Xiang, Wei

    2016-12-01

    The Eu(2)(+) -induced enhancement of defect luminescence of ZnS was studied in this work. While photoluminescence (PL) spectra exhibited 460 nm and 520 nm emissions in both ZnS and ZnS:Eu nanophosphors, different excitation characteristics were shown in their photoluminescence excitation (PLE) spectra. In ZnS nanophosphors, there was no excitation signal in the PLE spectra at the excitation wavelength λex  > 337 nm (the bandgap energy 3.68 eV of ZnS); while in ZnS:Eu nanophosphors, two excitation bands appeared that were centered at 365 nm and 410 nm. Compared with ZnS nanophosphors, the 520 nm emission in the PL spectra was relatively enhanced in ZnS:Eu nanophosphors and, furthermore, in ZnS:Eu nanophosphors the 460 nm and 520 nm emissions increased more than 10 times in intensity. The reasons for these differences were analyzed. It is believed that the absorption of Eu(2)(+) intra-ion transition and subsequent energy transfer to sulfur vacancy, led to the relative enhancement of the 520 nm emission in ZnS:Eu nanophosphors. In addition, more importantly, Eu(2)(+) acceptor-bound excitons are formed in ZnS:Eu nanophosphors and their excited levels serve as the intermediate state of electronic relaxation, which decreases non-radiative electronic relaxation and thus increases the intensity of the 460 nm and 520 nm emission dramatically. In summary, the results in this work indicate a new mechanism for the enhancement of defect luminescence of ZnS in Eu(2)(+) -doped ZnS nanophosphors. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Spectroscopic studies on the interaction of morin-Eu(III) complex with calf thymus DNA

    NASA Astrophysics Data System (ADS)

    Zhang, Guowen; Guo, Jinbao; Pan, Junhui; Chen, Xiuxia; Wang, Junjie

    2009-04-01

    The interaction between morin-Eu(III) complex and calf thymus DNA in physiological buffer (pH 7.4) was investigated using UV-vis spectrophotometry, fluorescence spectroscopy, viscosity measurements and DNA melting techniques. Hypochromicity and red shift of the absorption spectra of morin-Eu(III) complex were observed in the presence of DNA, and the fluorescence intensity of morin-Eu(III) complex was greatly enhanced with the addition of DNA. Moreover, fluorescence quenching and blue shift of the emission peak were seen in the DNA-ethidium bromide (EB) system when morin-Eu(III) complex was added. The relative viscosity of DNA increased with the addition of morin-Eu(III) complex, whereas the value of melting temperature of DNA-EB system decreased in the presence of morin-Eu(III) complex. All these results indicated that morin-Eu(III) complex can bind to DNA and the major binding mode is intercalative binding. The 3:1 morin:Eu(III) complex (estimated binding constant = 2.36 × 10 6 L mol -1) is stabilized by intercalation into the DNA. The calculated binding constants of morin-Eu(III) complex with DNA at 292, 301 and 310 K were 7.47 × 10 4, 8.89 × 10 4 and 1.13 × 10 5 L mol -1, respectively. The thermodynamic parameters were also obtained: Δ H θ was 20.14 kJ mol -1 > 0 and Δ S θ was 161.70 J mol -1 K -1 > 0, suggesting that hydrophobic force plays a major role in the binding of morin-Eu(III) complex to DNA.

  13. EuCo2P2 : A model molecular-field helical Heisenberg antiferromagnet

    NASA Astrophysics Data System (ADS)

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; Johnston, D. C.

    2016-07-01

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the a b plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ , high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T ≤TN with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ˜T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2 , respectively. These values are enhanced by a factor of ˜2.5 above those found from DFT electronic structure calculations for the two compounds. The calculations also find ferromagnetic Eu-Eu exchange interactions within the a b plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χa b(T ≤TN) .

  14. Scintillation Properties of Eu2+-Activated Barium Fluoroiodide

    SciTech Connect

    Gundiah, Gautam; Bourret-Courchesne, Edith; Bizarri, Gregory; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew; Moses, William W.; Derenzo, Stephen E.

    2009-11-18

    The scintillation properties of powders and single-crystals of BaFI doped with Eu2+ are presented. Single crystals were grown by the vertical Bridgman technique. Under optical and X-ray excitation, the samples exhibit a narrow E2+ 5d-4f transition emission centered at 405 nm. The scintillation light output is estimated to be 55,000+-5,000 photons/MeV at 662 keV with 85percent of the light decaying within 600 ns. An energyresolution of 8.5percent full width at half maximum (FWHM) has been achieved using this scintillator for 662 keV excitation (137Cs source) at room temperature.

  15. EU Funded Research Activities on NPPS Operational Safety

    SciTech Connect

    Manolatos, P.; Van Goethem, G.

    2002-07-01

    The 5. framework programme (FP-5), the pluri-annual research programme of the European Union (EU), covers the period 1998-2002. Research on nuclear energy, fusion and fission, is covered by the EURATOM part of the FP-5. An overview of the Euratom's research on Nuclear Reactor Safety, managed by the DG-RTD of the European Commission (EC), is presented. This concerns 70 multi-partner projects of approximately euro 82.5 million total contract value that have been selected and co-financed during the period 1999-2001. They form the three clusters of projects dealing with the 'Operational Safety of Existing Installations'. 'Plant Life Extension and Management' (PLEM), 'Severe Accident Management' (SAM) and 'Evolutionary concepts' (EVOL). Emphasis is given here to the projects of the PLEM cluster. (authors)

  16. Accelerator science and technology in Europe: EuCARD 2012

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2012-05-01

    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 third annual meeting of the EuCARD - European Coordination of Accelerator Research and Development. The conference concerns building of the research infrastructure, including in this advanced photonic and electronic systems for servicing large high energy physics experiments. There are debated a few basic groups of such systems like: measurement - control networks of large geometrical extent, multichannel systems for large amounts of metrological data acquisition, precision photonic networks of reference time, frequency and phase distribution.

  17. Arsenic detection in water: YPO4:Eu3+ nanoparticles

    NASA Astrophysics Data System (ADS)

    Ghosh, Debasish; Luwang, Meitram Niraj

    2015-12-01

    This work reports on the novel technique of detection of arsenic in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Eu3+ (5%) doped YPO4nanorodswere utilised for the said experiment. Co-precipitation method was used for the synthesis of the materials and characterised them with different instrumental techniques like X-ray diffraction (XRD), Infra-red (IR), UV-absorption, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence studies. This nanoparticle can adsorb both arsenic and arsenious acids. We studied the effect of arsenic adsorption on the luminescence behaviour of the nanoparticles. Arsenic acid enhanced the luminescence intensity whereas arsenious acid quenched the luminescence. This luminescence enhancement or quenching is related with arsenic concentration. This relation of luminescence property with concentration of arsenic can be used to detect arsenic in industrial waste.

  18. Characterization and Properties of Nanocrystalline EuAlO3

    NASA Astrophysics Data System (ADS)

    Petrov, D.; Angelov, B.; Lovcnmov, V.; Simeonova, P.

    2010-01-01

    Single-phase nanocrystals of europium monoaluminate have been prepared by the sol-gel method. EuAlO3 has been synthesized from europium oxide, aluminium nitrate, malic acid and 1,2-ethanediol as initial compounds with final temperature of annealing 950° C. The material has been characterized by XRD, SEM, EDS, TEM, and XPS. The temperature dependence of AC magnetic susceptibility in the range 2-300 K was also measured. The smallest nanoparticles have size 25 nm and form agglomerates. The material has pycnometric density of 7.009 g/cm3 at T = 293.15 K and specific surface area 15.0 m2/g.

  19. Tritium adsorption/release behaviour of advanced EU breeder pebbles

    NASA Astrophysics Data System (ADS)

    Kolb, Matthias H. H.; Rolli, Rolf; Knitter, Regina

    2017-06-01

    The tritium loading of current grades of advanced ceramic breeder pebbles with three different lithium orthosilicate (LOS)/lithium metatitanate (LMT) compositions (20-30 mol% LMT in LOS) and pebbles of EU reference material, was performed in a consistent way. The temperature dependent release of the introduced tritium was subsequently investigated by temperature programmed desorption (TPD) experiments to gain insight into the desorption characteristics. The obtained TPD data was decomposed into individual release mechanisms according to well-established desorption kinetics. The analysis showed that the pebble composition of the tested samples does not severely change the release behaviour. Yet, an increased content of lithium metatitanate leads to additional desorption peaks at medium temperatures. The majority of tritium is released by high temperature release mechanisms of chemisorbed tritium, while the release of physisorbed tritium is marginal in comparison. The results allow valuable projections for the tritium release behaviour in a fusion blanket.

  20. Setting priorities for EU healthcare workforce IT skills competence improvement.

    PubMed

    Li, Sisi; Bamidis, Panagiotis D; Konstantinidis, Stathis Th; Traver, Vicente; Car, Josip; Zary, Nabil

    2017-04-01

    A major challenge for healthcare quality improvement is the lack of IT skills and knowledge of healthcare workforce, as well as their ambivalent attitudes toward IT. This article identifies and prioritizes actions needed to improve the IT skills of healthcare workforce across the EU. A total of 46 experts, representing different fields of expertise in healthcare and geolocations, systematically listed and scored actions that would improve IT skills among healthcare workforce. The Child Health and Nutrition Research Initiative methodology was used for research priority-setting. The participants evaluated the actions using the following criteria: feasibility, effectiveness, deliverability, and maximum impact on IT skills improvement. The leading priority actions were related to appropriate training, integrating eHealth in curricula, involving healthcare workforce in the eHealth solution development, improving awareness of eHealth, and learning arrangement. As the different professionals' needs are prioritized, healthcare workforce should be actively and continuously included in the development of eHealth solutions.

  1. [Unemployment, suicide- and homicide-rates in the EU countries].

    PubMed

    Ritter, Kristina; Stompe, Thomas

    2013-01-01

    While the link between the unemployment and the national suicide rates is confirmed by various studies, there are few investigations on the impact of unemployment on homicide rates. In particular, it is not known whether suicide and homicide are associated with the same socio-economic factors. Using linear regression method, the influence of unemployment rates, per capita incomes and annual alcohol consumption on suicide and homicide rates was examined in the 27 EU states. We found a positive correlation between suicide and homicide rates. Unemployment among men is a strong predictor not only for suicide- but also for homicide rates. Suicide rates in men are also affected by the annual alcohol consumption. The suicide rates in women, however, correlate neither with socio-economic variables nor with alcohol consumption. Unemployment seems to have a stronger impact on the male than on the female identity. Since the former is still highly dependent on predetermined social roles.

  2. Synthesis and Photoluminescence Characteristics of Eu(3+)-Doped Molybdates Nanocrystals.

    PubMed

    Li, Fuhai; Yu, Lixin; Wei, Shuilin; Sun, Jiaju; Chen, Weiqing; Sun, Wei

    2015-12-01

    In this paper, the Eu(3+)-doped molybdate (CaMoO4, ZnMoO4 and BaMoO4) phosphors have been prepared by a hydrothermal method through modulating the pH value of the precursor solution (pH = 8, 10, and 12, respectively). The crystalline phase, morphology, photoluminescent properties of the prepared samples were systematically characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and photoluminescence (PL) spectra. The results indicate that the photoluminescence and morphology can be affected by the precursor solution. And the growth of the ZnMoO4 crystals also can be affected by the pH value of the precursor solution.

  3. Treatment and disposal of tyres: Two EU approaches. A review.

    PubMed

    Torretta, Vincenzo; Rada, Elena Cristina; Ragazzi, Marco; Trulli, Ettore; Istrate, Irina Aura; Cioca, Lucian Ionel

    2015-11-01

    The treatment and disposal of tyres from vehicles has long been of considerable environmental importance. The main problem lies in the mixed composition of the tyres. Studies have been undertaken to modify the structure of the tyres, especially with reference to the percentage of granulated rubber incorporated, in order to improve their performance, and also to reduce their environmental impact during normal functioning (noise, particulates, etc.) and facilitate recycling and final disposal. The aim of the present study is to review and compare how used tyres are treated and disposed of in two different EU countries. The first is Italy, which has been part of the European Union since its inception, and has important industrial traditions. The second is Romania, an emerging country which recently became part of the EU, and whose economic and industrial development has had a major boost in recent years, with a strong growth in waste production, together with consumption in urban areas. The occasion was useful to consider the situation concerning the evolution of the different aspects related to the management of the end-of-life tyres. In particular, the paper considers the properties of tyre waste and their potential reuse, the enhancement of end-of-life tires and the various types of recovery, such as the reconstruction of tyres and the material recovery. The aspects related to the energy recovery and the use of the life cycle analysis, as a tool to support the choices of the best management system, were also taken into consideration, not forgetting that an adequate end-of-life planning is important when developing a sustainable product, since it can affect considerably its overall life cycle.

  4. Nuclear Quadrupole Resonance Measurement of the Ferromagnetic Filled-Skutterudite Compound EuRu4Sb12

    NASA Astrophysics Data System (ADS)

    Koyama, Takehide; Maeda, Yoshitaka; Ueda, Koichi; Mito, Takeshi; Sugawara, Hitoshi

    2015-08-01

    We report the detailed analysis of the 101Ru nuclear quadrupolar resonance spectrum in the ferromagnetically ordered state of EuRu4Sb121 and propose that Eu 4f moments align in the [111] direction. The localized character of Eu 4f electrons is suggested from the temperature dependence of the nuclear spin-lattice relaxation rate.

  5. Density-functional study of structural, electronic, and magnetic properties of the EuSin (n=1-13) clusters

    NASA Astrophysics Data System (ADS)

    Zhao, Gao-feng; Sun, Jian-min; Gu, Yu-zong; Wang, Yuan-xu

    2009-09-01

    The geometries, stabilities, and electronic and magnetic properties of europium encapsulated EuSin (n =1-13) clusters have been investigated systematically by using relativistic density functional theory with generalized gradient approximation. Starting from n =12, the Eu atom completely falls into the center of the Si frame, i.e., EuSi12 is the smallest fully endohedral Eu silicon cluster. The interesting finding is in good agreement with the recent experimental results on the photoelectron spectroscopy of the europium silicon clusters [A. Grubisic, H. P. Wang, Y. J. Ko, and K. H. Bowen, J. Chem. Phys. 129, 054302 (2008)]. The magnetic moments of the EuSin (n =1-13) clusters are also studied, and the results show that the total magnetic moments of the EuSin clusters and the magnetic moments on Eu do not quench when the Eu is encapsulated in the Si outer frame cage. It is concluded that most of the 4f electrons of the Eu atom in the EuSi12 cluster do not interact with the silicon cage and the total magnetic moments are overwhelming majority contributed by the 4f electrons of the Eu atom. According to the binding energy per atom, the second difference in energy (Δ2E), and vertical ionization potential, the EuSin (n =4,9,12) clusters are very stable.

  6. Luminescence of Eu and Ce in K3Ca2(SO4)3F fluoride material.

    PubMed

    Poddar, Anuradha; Gedam, S C; Dhoble, S J

    2015-09-01

    A new halophosphor K3Ca2(SO4)3F activated by Eu or Ce and K3Ca2(SO4)3F:Ce,Eu co-doped halosulfate phosphor has been synthesized by the co-precipitation method and characterized for its photoluminescence (PL). The PL emission spectra of the K3Ca2(SO4)3F:Ce phosphor show emission at 334 nm when excited at 278 nm due to 5d → 4f transition of Ce(3+) ions. In the K3Ca2(SO4)3F:Eu lattice, Eu(2+) (440 nm) as well as Eu(3+) (596 nm and 615 nm) emissions have been observed showing (5) D0 →(7) F1 and (5) D0 →(7) F2 transition of the Eu(3+) ion, which is in the blue and red region of the visible spectrum respectively. The trivalent europium ion is very useful for studying the nature of metal coordination in various systems owing to its non-degenerate emitting (5) D0 state. K3Ca2(SO4)3F:Ce,Eu is suitable for Ce(3+) → Eu(2+) → Eu(3+) energy transfer in which Ce(3+) and Eu(2+) play the role of sensitizers and Eu(2+) and Eu(3+) act as the activators. The observations presented in this paper are relevant for lamp phosphors.

  7. Electrospinning preparation and properties of NaGdF 4:Eu 3+ nanowires

    NASA Astrophysics Data System (ADS)

    Dali, Liu; Guolei, Wang; Biao, Dong; Xue, Bai; Yu, Wang; Hongwei, Song; Lin, Xu

    2010-10-01

    Eu 3+ doped NaGdF 4 (NaGdF 4:Eu 3+) nanocrystals in hexagonal crystal phase were prepared by a polyol method, and the size and morphology controllable NaGdF 4:Eu 3+/PVP nano-composite fibers were obtained through the electrospinning technique, and then the NaGdF 4:Eu 3+ nanowires were obtained by followed annealing. By changing the ratio of PVP to NaGdF 4 as well as the calcination temperature, the optimal conditions for synthesizing the NaGdF 4 nanowires were obtained, and the structural properties of the synthesized sample were characterized by powder X-ray diffraction (XRD) patterns and field emission scanning electron micrographs (SEM) images. The luminescent properties of the NaGdF 4:Eu 3+ nanocrystals and nanowires were also studied in this paper. We observed that the luminescent intensity of NaGdF 4:Eu 3+ nanowires was greatly increased compared to the annealed NaGdF 4:Eu 3+ nanocrystals at the same temperature.

  8. Synthesis, characterization and photoluminescence properties of CaSiO3:Eu3+ red phosphor.

    PubMed

    Nagabhushana, H; Nagabhushana, B M; Madesh Kumar, M; Chikkahanumantharayappa; Murthy, K V R; Shivakumara, C; Chakradhar, R P S

    2011-01-01

    CaSiO3:Eu3+ (1-5 mol%) red emitting phosphors have been synthesized by a low-temperature solution combustion method. The phosphors have been well characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical spectroscopy. PXRD patterns reveal monoclinic CaSiO3 phase can be obtained at 900°C. The SEM micrographs show the crystallites with irregular shape, mostly angular. Upon 254 nm excitation, the phosphor show characteristic fluorescence 5D0→7FJ (J=0, 1, 2, 3, 4) of the Eu3+ ions. The electronic transition located at 614 nm corresponding to 5D0→7F2 of Eu3+ ions, which is stronger than the magnetic dipole transition located at 593 nm corresponding to 5D0→7F1 of Eu3+ ions. Different pathways involved in emission process have been studied. Concentration quenching has been observed for Eu3+ concentration>4 mol%. UV-visible absorption shows an intense band at 240 nm in undoped and 270 nm in Eu3+ doped CaSiO3 which is attributed to oxygen to silicon (O-Si) ligand-to-metal charge-transfer (LMCT) band in the SiO3(2-) group. The optical energy band gap is widened with increase of Eu3+ ion dopant. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. An integrated and sustainable EU health information system: national public health institutes' needs and possible benefits.

    PubMed

    Bogaert, Petronille; Van Oyen, Herman

    2017-01-01

    Although sound data and health information are at the basis of evidence-based policy-making and research, still no single, integrated and sustainable EU-wide public health monitoring system or health information system exists. BRIDGE Health is working towards an EU health information and data generation network covering major EU health policy areas. A stakeholder consultation with national public health institutes was organised to identify the needs to strengthen the current EU health information system and to identify its possible benefits. Five key issues for improvement were identified: (1) coherence, coordination and sustainability; (2) data harmonization, collection, processing and reporting; (3) comparison and benchmarking; (4) knowledge sharing and capacity building; and (5) transferability of health information into evidence-based policy making. The vision of an improved EU health information system was formulated and the possible benefits in relation to six target groups. Through this consultation, BRIDGE Health has identified the continuous need to strengthen the EU health information system. A better system is about sustainability, better coordination, governance and collaboration among national health information systems and stakeholders to jointly improve, harmonise, standardise and analyse health information. More and better sharing of this comparable health data allows for more and better comparative health research, international benchmarking, national and EU-wide public health monitoring. This should be developed with the view to provide the tools to fight both common and individual challenges faced by the Members States and their politicians.

  10. Energetics and electronic structure of GaN codoped with Eu and Si

    NASA Astrophysics Data System (ADS)

    Bruno Cruz, A. Vallan; Shinde, Prashant P.; Kumar, Vijay; Zavada, John M.

    2012-01-01

    First principles calculations using pseudopotentials and generalized gradient approximation (GGA) for the exchange-correlation energy show that addition of Si makes Eu doping in GaN energetically favorable. It breaks local symmetry around Eu ions and leads to shallow states below the conduction band that could facilitate intra-4f shell transitions. Silicon atoms on Ga sites act as intrinsic donors transforming Eu from a 3+ to a 2+ state. The half-filled 4f states with a 7 μB magnetic moment on each Eu ion lie within the band gap of GaN and are narrower compared with the only-Eu doping case due to reduced hybridization with the host states. There is a tendency for clustering of Eu ions with ferromagnetic coupling and the ˜5-Å interatomic distance, but EuN phase formation is unfavorable. Further effects of the inclusion of onsite Coulomb interaction U within GGA+U formalism on the electronic structure are discussed.

  11. Charge state of vacancy defects in Eu-doped GaN

    NASA Astrophysics Data System (ADS)

    Mitchell, B.; Hernandez, N.; Lee, D.; Koizumi, A.; Fujiwara, Y.; Dierolf, V.

    2017-08-01

    Eu ions have been doped into GaN in order to achieve red luminescence under current injection, where coupling between the Eu ions and intrinsic defects such as vacancies are known to play an important role. However, the charge state of the vacancies and the impact it would have on the optical and magnetic properties of the Eu ions have not been explored. Through a combination of first-principle calculations and experimental results, the influence of the charge state of the defect environment surrounding the Eu ions has been investigated. We have identified two Eu centers that are related through the charge state of a local vacancy defect. These two centers were found to exhibit a mutual metastability, such that each center can be excited in one configuration and emit as the other. This metastability was found to be dependent on temperature and the wavelength of the excitation laser. Furthermore, one of these centers was found to have an effective magnetic g factor that is substantially larger than what is expected for an isolated E u3 + ion and is explained by a change in the charge state of the defect environment around the Eu. This prediction could also offer a new explanation for the saturation magnetization previously observed in GaN : Eu and other GaN:RE systems.

  12. Research of the entry of rare earth elements Eu3+ and La3+ into plant cell.

    PubMed

    Gao, Yongsheng; Zeng, Fuli; Yi, An; Ping, Shi; Jing, Lanhua

    2003-03-01

    Whether rare earth elements can enter into plant cells remains controversial. This article discusses the ultracellular structural localization of lanthanum (La(3+)) and europium (Eu(3+)) in the intact plant cells fed by rare earth elements Eu(3+) and La(3+). Eu-TTA fluorescence analysis of the plasmalemma, cytoplast, and mitochondria showed that Eu(3+) fluorescence intensities in such structures significantly increased. Eu(3+) can directly enter or be carried by the artificial ion carrier A23187 into plant cells through the calcium ion (Ca(2+)) channel and then partially resume the synthesis of amaranthin in the Amaranthus caudatus growing in the dark. Locations of rare earth elements La(3+) and Eu(3+) in all kinds of components of cytoplasmatic organelles were determined with transmission electron microscope, scanning electron microscope, and energy-dispersive X-ray microanalysis. The results of energy-dispersive X-ray microanalysis indicated that Eu(3+) and La(3+) can be absorbed into plant cells and bind to the membranes of protoplasm, chloroplast, mitochondrion, cytoplast, and karyon. These results provide experimental evidence that rare earth elements can be absorbed into plant cells, which would be the basis for interpreting physiological and biochemical effects of rare earth elements on plant cells.

  13. Influence of Bi3+ ions on the excitation wavelength of the YVO4:Eu3+ matrix

    NASA Astrophysics Data System (ADS)

    Matos, Marcela G.; Rocha, Lucas A.; Nassar, Eduardo J.; Verelst, Marc

    2016-12-01

    This work used the non-hydrolytic sol-gel process to prepare co-activated Eu3+/Bi3+ in YVO4 phosphors. We employed X-ray diffraction, which confirmed a tetragonal structure, and photoluminescence to characterize the structure and investigate the photoluminescence properties of the YVO4:Eu3+,Bi3+ matrixes. The large band between 250 and 380 nm in the excitation spectrum of YVO4:Eu3+,Bi3+ corresponded to a ligand-metal charge transfer band (VO43- → Eu3+). Addition of Bi3+ ions increased the charge transfer band and intensified the emission of Eu3+ ions. The x and y color coordinates of the phosphors ranged from 0.60 to 0.68 and from 0.32 to 0.39, respectively. The emission spectrum displayed an intense red emission centered at 618.5 nm, due to the 5D0 → 7F2 transition of Eu3+. The optimal Bi3+ concentration in the phosphor was 1% in mol, which provided more intense emission and longer lifetime. The results indicated that YVO4:Eu3+,Bi3+ is a potential red phosphor with application as biological marker.

  14. Luminescence properties of rare earth doped metal oxide nanostructures: A case of Eu-ZnO

    NASA Astrophysics Data System (ADS)

    Sahu, D.; Acharya, B. S.; Panda, N. R.

    2016-05-01

    The present study reports the growth and luminescence properties of Eu doped ZnO nanostructures. The experiment has been carried out by synthesizing the materials by simple wet-chemical method. X-ray diffraction (XRD) studies show expansion of ZnO lattice with the incorporation of Eu ions which has been confirmed from the appearance of Eu2O3 as a minor phase in the XRD pattern. The estimation of crystallite size from XRD results matches closely with the results obtained from transmission electron microscopy. Further, these results show the formation of nanosized Eu-ZnO particles of average size around 60 nm stacked on each other. FTIR studies show the presence of both Zn-O and Eu-O modes in the spectra supporting the results obtained from XRD. The interesting results obtained from photoluminescence (PL) measurements show the presence of both band edge emission in UV region and the defect emissions in violet, blue and green region. The appearance of 5D0→7FJ transitions of Eu3+ ions in red region clearly suggests the possible occurrence of energy transfer between the energy states of ZnO host and Eu3+ ions.

  15. Luminescence properties of rare earth doped metal oxide nanostructures: A case of Eu-ZnO

    SciTech Connect

    Sahu, D.; Acharya, B. S.; Panda, N. R.

    2016-05-06

    The present study reports the growth and luminescence properties of Eu doped ZnO nanostructures. The experiment has been carried out by synthesizing the materials by simple wet-chemical method. X-ray diffraction (XRD) studies show expansion of ZnO lattice with the incorporation of Eu ions which has been confirmed from the appearance of Eu{sub 2}O{sub 3} as a minor phase in the XRD pattern. The estimation of crystallite size from XRD results matches closely with the results obtained from transmission electron microscopy. Further, these results show the formation of nanosized Eu-ZnO particles of average size around 60 nm stacked on each other. FTIR studies show the presence of both Zn-O and Eu-O modes in the spectra supporting the results obtained from XRD. The interesting results obtained from photoluminescence (PL) measurements show the presence of both band edge emission in UV region and the defect emissions in violet, blue and green region. The appearance of {sup 5}D{sub 0}→{sup 7}F{sub J} transitions of Eu{sup 3+} ions in red region clearly suggests the possible occurrence of energy transfer between the energy states of ZnO host and Eu{sup 3+} ions.

  16. Luminescent chemosensors for amines and ammonia based on Eu(III) chelate complexes

    NASA Astrophysics Data System (ADS)

    Sergeev, Alexander A.; Voznesenskiy, Sergey S.; Petrochenkova, Nataliya V.; Shishov, Alexander S.; Leonov, Andrei A.; Emelina, Tatiana B.; Mirochnik, Anatolii G.; Kulchin, Yuri N.

    2016-11-01

    Here we report a novel luminescent sensor for amines and ammonia based on Eu(III) tris-β-benzoylacetonate complexes obtained in various conditions. It has been revealed that interaction of Eu(III) tris-β-benzoylacetonate with analyte vapor results in increase of the Eu(III) luminescence intensity. Exposure of Eu(III) complexes to ammonia and methylamine vapors results in a rapid increase of the emission and excitation spectra intensity and a rapid recovery, almost to the initial value, when the sample is exposed to air. Moreover, luminescence decay time value of Eu(III) complexes is in dependence on analyte presence and increase in ammonia atmosphere and decrease under purging of pure air. The dependences of sensor response features upon preparation conditions were shown. The mechanism of the analyte vapors effect on Eu(III) luminescence intensification has been suggested using the data of IR spectroscopy and quantum chemistry calculations. The mechanism of luminescence sensitization consists in bonding of an analyte molecule with a water molecule into the coordination sphere of Eu(III). As a result, the bond of a water molecule with the luminescence center weakens and the blockage of the quenching of luminescence on OH-vibrations takes place. The obtained data can be used for development of sensor materials with selective optical sensitivity to ecologically harmful vapours of organic and inorganic compounds.

  17. Tunable luminescence properties and energy transfer in LaAl₁₁O₁₈:Eu,Tb phosphor.

    PubMed

    Mendhe, M S; Puppalwar, S P; Dhoble, S J

    2016-05-01

    Eu(2+) and Tb(3+) singly doped and co-doped LaAl11O18 phosphors were prepared by a combustion method using urea as a fuel. The phase structure and photoluminescence (PL) properties of the prepared phosphors were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence excitation and emission spectra. When the content of Eu(2+) was fixed at 0.01, the emission chromaticity coordinates could be adjusted from blue to green region by tuning the contents of Tb(3+) ions from 0.01 to 0.03 through an energy transfer (ET) process. The fluorescence data collected from the samples with different contents of Tb(3+) into LaAl11O18: Eu, show the enhanced green emission at 545 nm associated with (5)D(4)-(7)F(5) transitions of Tb(3+). The enhancement was attributed to ET from Eu(2+) to Tb(3+), and therefore Eu(2+) ion acts as a sensitizer (an energy donor) while Tb(3+) ion as an activator. The ET from Eu(2+) to Tb(3+) is performed through dipole-dipole interaction. The ET efficiency and critical distance were also calculated. The present Eu(2+)-Tb(3+) co-doped LaAl11O18 phosphor will have potential application for UV convertible white light-emitting diodes. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Structure and physical properties of EuTa2O6 tungsten bronze polymorph

    NASA Astrophysics Data System (ADS)

    Kolodiazhnyi, T.; Sakurai, H.; Vasylkiv, O.; Borodianska, H.; Forbes, S.; Mozharivskyj, Y.

    2014-08-01

    A tetragonal tungsten bronze (TTB) polymorph of EuTa2O6 was prepared and analyzed. EuTa2O6 crystallizes in the centrosymmetric Pnam space group (with unit cell: a = 12.3693, b = 12.4254, and c = 7.7228 Å) isomorphous with orthorhombic β-SrTa2O6. In contrast to early reports, we see no evidence of deviation from paramagnetic Curie-Weiss behavior among the Eu2+ 4f7spins in EuTa2O6 down to 2 K. Dielectric constant shows a broad peak at ca. 50 K with dielectric dispersion resembling diffuse phase transition. The relaxation time, however, follows a simple (non-freezing) thermally activated process with an activation energy of 92 meV and an attempt frequency of f0 = 5.79 × 1012 Hz. A thermal conductivity of EuTa2O6 shows a low-temperature (T ≈ 30 K) "plateau" region reminiscent of a glass-like behaviour in Nb-based TTB compounds. This behaviour can be attributed to the loosely bound Eu2+ ions occupying large tricapped trigonal prismatic sites in the EuTa2O6 structure.

  19. Fluctuation-induced first-order transition in Eu-based trillium lattices

    NASA Astrophysics Data System (ADS)

    Franco, Diego G.; Prots, Yurii; Geibel, Christoph; Seiro, Silvia

    2017-07-01

    Among spin arrangements prone to geometric frustration, the so-called trillium lattice has not been very intensively investigated. A few theoretical works show that it is at the border between a degenerate, an only partially ordered, and a fully ordered ground state. However, only few compounds with this structure have been studied, and there is presently no good example of a trillium lattice with an antiferromagnetic ground state and clear evidence for frustration effects. We present magnetic and specific heat measurements on two realizations of a trillium lattice of local spins, EuPtSi and EuPtGe. Both compounds exhibit a similar magnetic behavior, with Eu2 + moments ordering antiferromagnetically at TN=4.1 K (EuPtSi) and 3.3 K (EuPtGe), albeit retaining a considerable amount of entropy in strong magnetic fluctuations extending to temperatures well above TN. The magnetic entropy reaches only roughly half of R ln8 at TN. These fluctuations are presumably the source for the pronounced first-order character of the transition at TN and are likely due to magnetic frustration. Thus, EuPtSi and EuPtGe open a new door to experimental studies of frustration effects in the trillium lattice and provide a testing ground for theoretical predictions.

  20. Template synthesis and luminescence properties of TiO{sub 2}:Eu{sup 3+} nanotubes

    SciTech Connect

    Zhao, Huan; Zheng, Keyan; Sheng, Ye; Li, Hongbo; Zhang, Hongguang; Qi, Xiaofei; Shi, Zhan; Zou, Haifeng

    2014-02-15

    Uniform TiO{sub 2}:Eu{sup 3+} nanotubes have been successfully synthesized through a simple solvothermal process with carbon nanotubes (CNTs) as templates, free of any surfactant or catalyst. X-ray diffraction (XRD) results demonstrate that the product is a pure anatase phase of TiO{sub 2}. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images indicate that the as-obtained TiO{sub 2}:Eu{sup 3+} nanotubes are uniform in size and distribution, and the thickness of the wall is about 8 nm. The possible formation mechanism has also been proposed. The luminescent spectrum shows that TiO{sub 2}:Eu{sup 3+} nanotubes exhibit a red emission at 612 nm due to the {sup 5}D{sub 0}→{sup 7}F{sub 2} transition. Furthermore, this synthetic route is promising for the preparation of other one-dimensional inorganic nanomaterials because of its simplicity and the low cost of the starting reagents. - Graphical abstract: This picture is the illustration for the formation process of TiO{sub 2}:Eu{sup 3+} nanotubes. Display Omitted - Highlights: • TiO{sub 2}:Eu{sup 3+} nanotubes have been prepared through a simple solvothermal process. • The TiO{sub 2}:Eu{sup 3+} nanotubes are uniform in size and distribution. • Under UV light excitation, the TiO{sub 2}:Eu{sup 3+} nanotubes show strong red emission.

  1. Investigation on the Synthesis and Photoluminescence of CaMoO4:Eu3+ Microspheres.

    PubMed

    Li, Jinping; Zhu, Gangqiang; Zhang, Tingting; Zheng, Hairong

    2016-04-01

    Eu3+ doped CaMoO4 microspheres were synthesized via a facile hydrothermal method assisted by the citric acid additive. The structure and morphology of the samples were examined by X-ray diffractometer (XRD) and scanning electron microscopy (SEM), and the properties of the photoluminescence emission from the samples were investigated with spectroscopic technique. The XRD results revealed that the hydrothermally formed CaMoO4:Eu3+ phosphor has single-phase scheelite-type tetragonal structure. The SEM observation demonstrated that the samples have sphere-like morphologies and their diameters were about 3-4 µm. Meanwhile, the influence of the citric acid on the formation of CaMoO4:Eu3+ was also investigated. The formation mechanism of CaMoO4:Eu3+ microspheres was explored based on the time-dependent experimental observation. The study on the luminescence spectra showed that CaMoO4:Eu3+ microspheres can be effectively excited at 395 nm, and good luminescence emission can be obtained at around 614 nm, which is attributed to the transition of 5D0 --> 7F2 from Eu3+. The current study suggests that CaMoO4:Eu3+ red phosphor is a potential candidate for white light-emitting diodes (WLEDs) application.

  2. Spectroscopic investigations and phonon side band analysis of Eu3+-doped multicomponent tellurite glasses

    NASA Astrophysics Data System (ADS)

    Sajna, M. S.; Gopi, Subash; Prakashan, V. P.; Sanu, M. S.; Joseph, Cyriac; Biju, P. R.; Unnikrishnan, N. V.

    2017-08-01

    Novel and optically efficient multicomponent tellurite glasses doped with Eu3+ ions were prepared by melt quenching procedure. Absorption, photoluminescence excitation, emission and Raman spectra analyses of the Eu3+-doped glasses have been carried out. Spectroscopic studies were performed with the Judd-Ofelt and phonon side band analyses. The local vibrational mode around Eu3+ ions and the phonon energy of the prepared tellurite glasses was estimated by the phonon side band (PSB) associated with 7F0→5D2 transition of Eu3+ ion. Both the phonon energy (ћω) and the electron-phonon coupling constant (g) were derived from the phonon side band spectrum. Radiative properties such as spontaneous transition probabilities (AT), radiative lifetime (τR) and luminescence branching ratio (βR) ratio were calculated for different excited states. Five pronounced peaks have appeared in the photoluminescence spectra (PL) as a result of the transitions from the metastable 5D0 to the ground states 7FJ (J = 0 to 4) of Eu3+ ions. The red Eu3+ emission at 612 nm corresponding to the 5D0→7F2 transition is of particular importance and its emission intensity is observed to increase significantly with growing Eu3+ ion concentration, suggesting that these multicomponent tellurite glasses are suitable candidates for red laser source applications.

  3. Sensitized luminescence of Sm3+,Eu(3+)-codoped TiO2 nanoparticles.

    PubMed

    Luo, Wenqin; Li, Renfu; Liu, Yongsheng; Chen, Xueyuan

    2010-03-01

    Sm3+,Eu(3+)-codoped TiO2 nanoparticles were prepared by a facile sol-gel-solvothermal method. Sm3+ and Eu3+ were successfully incorporated into a TiO2 lattice and resulted in intense emission lines with resolved crystal-field splitting, in spite of a large mismatch in ionic radius between trivalent lanthanides (Ln3+) and Ti4+. The intense sensitized emissions of Sm3+ and Eu3+ ions by TiO2 host were obtained at room temperature. In this case, Sm3+ also acts as a bridge to transfer energy from TiO2 host to Eu3+ ions, which was not observed in Eu(3+)-doped TiO2 nanoparticles. In comparison with direct excitation of lanthanide ions, the luminescence lifetimes of 4G5/2 of Sm3+ and 5D0 of Eu3+ were observed to be significantly prolonged upon excitation above TiO2 band-gap. A sensitization mechanism to illustrate the energy transfer from TiO2 to Sm3+ and Eu3+ was proposed based on the optical behaviors of the codoped nanoparticles.

  4. Synthesis and luminescent properties of novel BaGd2O4:Eu3+ scintillating phosphor.

    PubMed

    Sun, Xin-Yuan; Wang, Wen-Feng; Sun, Shou-Qiang; Lin, Liang-Wu; Li, De-Yi; Zhou, Ling-Ping

    2013-01-01

    BaGd2-x O4:xEu(3+) and Ba1-y Gd1.79-2y Eu0.21 Na3y O4 phosphors were synthesized at 1300°C in air by conventional solid-state reaction method. Phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE) spectra, photoluminescence (PL) spectra and thermoluminescence (TL) spectra. Optimal PL intensity for BaGd2-x O4 :xEu(3+) and Ba1-y Gd1.79-2y Eu0.21 Na3y O4 phosphors at 276 nm excitation were found to be x = 0.24 and y = 0.125, respectively. The PL intensity of Eu(3+) emission could only be enhanced by 1.3 times with incorporation of Na(+) into the BaGd2 O4 host. Enhanced luminescence was attributed to the flux effect of Na(+) ions. However, when BaGd2 O4:Eu(3+) phosphors were codoped with Na(+) ions, the induced defects confirmed by TL spectra impaired the emission intensity of Eu(3+) ions.

  5. Sr3Bi(PO4)3:Eu2+ Luminescence, Concentration Quenching and Crystallographic Sites

    NASA Astrophysics Data System (ADS)

    Gao, Shao-Jie; Li, Ting; Zhang, Zi-Cai; Li, Pan-Lai; Wang, Zhi-Jun; Yang, Zhi-Ping

    2014-07-01

    A blue emitting phosphor Sr3Bi(PO4)3:Eu2+ is synthesized by a high-temperature solid state method, and its luminescent property is investigated. Sr3Bi(PO4)3:Eu2+ can create blue emission under the 332 radiation excitation, and the prominent luminescence in blue (423 nm) due to the 4f 5d1 →4 f7 transition of the Eu2+ ion. The crystallographic sites of the Eu2+ ion in Sr3Bi(PO4)3 are analyzed, and the 420 and 440 nm emission peaks of the Eu2+ ion are assigned to the nine-coordination and eight-coordination, respectively. The emission intensity of Sr3Bi(PO4)3:Eu2+ is influenced by the Eu2+ doping content, and the concentration quenching effect is observed. The quenching mechanism is the dipole-dipole interaction, and the critical distance of energy transfer is calculated by the concentration quenching method to be approximately 1.72 nm.

  6. Sacrificial template method for fabrication of submicrometer-sized YPO(4):Eu(3+) hierarchical hollow spheres.

    PubMed

    Zhang, Lihui; Jia, Guang; You, Hongpeng; Liu, Kai; Yang, Mei; Song, Yanhua; Zheng, Yuhua; Huang, Yeju; Guo, Ning; Zhang, Hongjie

    2010-04-05

    Large-scale good-quality submicrometer-sized YPO(4):Eu(3+) hollow spheres were synthesized by utilizing the colloidal spheres of Y(OH)CO(3):Eu(3+) as a sacrificial template and NH(4)H(2)PO(4) as a phosphorus source, for the first time. The whole process mainly consists of the hydrothermal reaction and acid erosion. The YPO(4):Eu(3+)@Y(OH)CO(3):Eu(3+) core-shell structures were first obtained after the hydrothermal process. Then, the remaining Y(OH)CO(3):Eu(3+) was removed by selective dissolution in a dilute nitric acid solution. The YPO(4):Eu(3+) hollow spheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL). The formation mechanism was also investigated. The obtained YPO(4):Eu(3+) hollow spheres may have potential applications in cell biology, drug release, and diagnosis, due to high chemical stability and luminescence functionality.

  7. Enhanced stability of Eu in GaN nanoparticles: Effects of Si co-doping

    SciTech Connect

    Kaur, Prabhsharan; Sekhon, S. S.; Zavada, J. M.; Kumar, Vijay

    2015-06-14

    Ab initio calculations on Eu doped (GaN){sub n} (n = 12, 13, and 32) nanoparticles show that Eu doping in nanoparticles is favorable compared with bulk GaN as a large fraction of atoms lie on the surface where strain can be released compared with bulk where often Eu doping is associated with a N vacancy. Co-doping of Si further facilitates Eu doping as strain from an oversized Eu atom and an undersized Si atom is compensated. These results along with low symmetry sites in nanoparticles make them attractive for developing strongly luminescent nanomaterials. The atomic and electronic structures are discussed using generalized gradient approximation (GGA) for the exchange-correlation energy as well as GGA + U formalism. In all cases of Eu (Eu + Si) doping, the magnetic moments are localized on the Eu site with a large value of 6μ{sub B} (7μ{sub B}). Our results suggest that co-doping can be a very useful way to achieve rare-earth doping in different hosts for optoelectronic materials.

  8. Hydrothermal synthesis and luminescence properties of KLa):Eu3+ phosphor

    NASA Astrophysics Data System (ADS)

    Yang, Zaifa; Sun, Yumei; Han, Liu; Xu, Denghui; Sun, Jiayue

    2016-04-01

    KLa):Eu3+ phosphors were prepared by the hydrothermal method. The after tuning of synthesis time and the ratio of the ethylene glycol to water ratio made the phosphor present different morphologies, including peanut-like shape and spheres. The samples were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), diffuse reflectance spectrum, and fluorescence spectrum. Under the excitation of 397 nm near-ultraviolet, the typical red emission produced by Eu3+ ions can be observed. And the phosphors show strong red light around 612 nm, attributed to D→F transition of Eu ion. The luminescence properties of the as-prepared phosphors were studied based on changing the synthesis condition. It is found that the synthesis time and the changing of the ratio of ethylene glycol to water play the crucial role in the formation of morphology. The optimum dopant concentration of Eu ions in KLa):Eu3+ is around 7 mol. %. Moreover, the fluorescence decay curve and thermal stability of luminescence were also investigated in detail. The Commission International de I'Eclairage coordinates of KLa):0.07Eu3+ located in the red reddish region. All the results suggest that KLa):0.07Eu3+ might be a promising reddish-orange emitting phosphor used in white light-emitting diodes (w-LED).

  9. Structure and spectroscopic properties of (Y, Eu)(PO3)3 polyphosphate red phosphors

    NASA Astrophysics Data System (ADS)

    Zhang, Xinguo; Chen, Peican; Wang, Zizhou; Zhou, Liya; Zhou, Fangxiang

    2016-08-01

    A series of orange-red emitting phosphor Y(PO3)3: xEu3+ (x = 0.1-1.0) was prepared by a solid-state reaction route. The phosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) as well as decay lifetimes. Studies revealed the phase transfer from monoclinic to orthorhombic when Y3+ is totally replaced by Eu3+, and expansion of the unit cell occurs with increasing Eu3+ doped content. The PL spectra show that the phosphors Y(PO3)3: xEu3+ can be effectively excited by near ultraviolet (n-UV) light, and exhibit strong red-orange emission with no concentration quenching. The profile of PL spectra changes significantly at high Eu3+ content (x ≥ 0.80), which is due to the variation of preference for substitution of Eu3+. The luminescence due to the 5D0 → 7FJ (J = 1, 2) transitions at 77 K exhibits its own spectral features for different crystallographic site. It is found that Eu3+ ions occupy the centers of octahedral polyhedron and form Ci/C1 point group in Y(PO3)3.

  10. Sonochemical synthesis of highly luminescent Ln2O3:Eu3+ (Y, La, Gd) nanocrystals

    DOE PAGES

    Alammar, Tarek; Cybinska, Joanna; Campbell, Paul S.; ...

    2015-05-12

    In this study, sonication of Ln(CH3COO)3·H2O, Eu(CH3COO)3·H2O and NaOH dissolved in the ionic liquid-butyl-3-methylimidazolium bis(trifluoromethane)sulfonylamide lead to Ln(OH)3:Eu (Ln: Gd, La, Y) nanoparticles. Subsequent calcination at 800 °C for 3 h allowed to obtain Ln2O3:Eu nanopowders. Gd2O3 and Y2O3 were obtained in the C-type lanthanide sequioxide structure, whereas La2O3 crystallized in the A-type. Structure, morphology, and luminescent properties of the nano-oxides were investigated by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), dispersive X-ray (EDX), and photoluminescence (PL). SEM studies revealed that the synthesized Gd2O3:Eu, La2O3:Eu, and Y2O3:Eu formed nano-spindle, -sheets, and -rods in shape, respectively. The nanoscale materials showmore » very efficient red emission due to the intraconfigurational f–f transitions of Eu3+. The quantum yields for Ln2O3:Eu (5%) were determined to be 4.2% for Ln=Gd, 13.8% for Ln=Y and 5.2% for Ln=La. The asymmetric ratio I02/I01 of Eu3+ varies from 5.3 for Gd2O3, to 5.6 for Y2O3 to 6.5 for La2O3, which increased the color chromaticity.« less

  11. EuCo2P2: A Model Molecular-Field Helical Heisenberg Antiferromagnet

    DOE PAGES

    Sangeetha, N. S.; Cuervo-Reyes, Eduardo; Pandey, Abhishek; ...

    2016-07-19

    The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2 structure containing Eu spins-7/2 was previously shown from single-crystal neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM) structure below TN=66.5 K with the helix axis along the c axis and with the ordered moments aligned within the ab plane. Here we report crystallography, electrical resistivity, heat capacity, magnetization, and magnetic susceptibility measurements on single crystals of this compound. We demonstrate that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from comparisons of the anisotropic magnetic susceptibility χ, high-field magnetization, and magnetic heat capacity of EuCo2P2 single crystals at temperature T≤TNmore » with the predictions of our recent formulation of molecular-field theory. Values of the Heisenberg exchange interactions between the Eu spins are derived from the data. The low-T magnetic heat capacity ~T3 arising from spin-wave excitations with no anisotropy gap is calculated and found to be comparable to the lattice heat capacity. The density of states at the Fermi energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and BaCo2P2, respectively. These values are enhanced by a factor of ~2.5 above those found from DFT electronic structure calculations for the two compounds. Additionally, the calculations also find ferromagnetic Eu–Eu exchange interactions within the ab plane and AFM interactions between Eu spins in nearest- and next-nearest planes, in agreement with the MFT analysis of χab(T≤TN).« less

  12. Fabrication of MPEG-b-PMAA capped YVO4:Eu nanoparticles with biocompatibility for cell imaging.

    PubMed

    Liu, Yue; Li, Xiao-Shuang; Hu, Jia; Guo, Miao; Liu, Wei-Jun; Feng, Yi-Mei; Xie, Jing-Ran; Du, Gui-Xiang

    2015-12-01

    A novel nanoparticle with multilayer core-shell architecture for cell imaging is designed and synthesized by coating a fluorescent YVO4:Eu core with a diblock copolymer, MPEG-b-PMAA. The synthesis of YVO4:Eu core, which further makes MPEG-b-PMAA-YVO4:Eu NPs adapt for cell imaging, is guided by the model determined upon the evaluation of pH and CEu%. The PMAA block attached tightly on the YVO4:Eu core forms the inner shell and the MPEG block forms the biocompatible outermost shell. Factors including reaction time, reaction temperature, CEu% and pH are optimized for the preparation of the YVO4:Eu NPs. A precise defined model is established according to analyzing the coefficients of pH and CEu% during the synthesis. The MPEG-b-PMAA-YVO4:Eu NPs, with an average diameter of 24 nm, have a tetragonal structure and demonstrate luminescence in the red region, which lies in a biological window (optical imaging). Significant enhancement in luminescence intensity by MPEG-b-PMAA-YVO4:Eu NPs formation is observed. The capping copolymer MPEG-b-PMAA improves the dispersibility of hydrophobic YVO4:Eu NPs in water, making the NPs stable under different conditions. In addition, the biocompatibility MPEG layer reduces the cytotoxicity of the nanoparticles effectively. 95% cell viability can be achieved at the NPs concentration of 800 mgL(-1) after 24h of culture. Cellular uptake of the MPEG-b-PMAA-YVO4:Eu NPs is evaluated by cell imaging assay, indicating that the NPs can be taken up rapidly and largely by cancerous or non-cancerous cells through an endocytosis mechanism. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Key features of an EU health information system: a concept mapping study.

    PubMed

    Rosenkötter, Nicole; Achterberg, Peter W; van Bon-Martens, Marja J H; Michelsen, Kai; van Oers, Hans A M; Brand, Helmut

    2016-02-01

    Despite the acknowledged value of an EU health information system (EU-HISys) and the many achievements in this field, the landscape is still heavily fragmented and incomplete. Through a systematic analysis of the opinions and valuations of public health stakeholders, this study aims to conceptualize key features of an EU-HISys. Public health professionals and policymakers were invited to participate in a concept mapping procedure. First, participants (N = 34) formulated statements that reflected their vision of an EU-HISys. Second, participants (N = 28) rated the relative importance of each statement and grouped conceptually similar ones. Principal Component and cluster analyses were used to condense these results to EU-HISys key features in a concept map. The number of key features and the labelling of the concept map were determined by expert consensus. The concept map contains 10 key features that summarize 93 statements. The map consists of a horizontal axis that represents the relevance of an 'organizational strategy', which deals with the 'efforts' to design and develop an EU-HISys and the 'achievements' gained by a functioning EU-HISys. The vertical axis represents the 'professional orientation' of the EU-HISys, ranging from the 'scientific' through to the 'policy' perspective. The top ranking statement expressed the need to establish a system that is permanent and sustainable. The top ranking key feature focuses on data and information quality. This study provides insights into key features of an EU-HISys. The results can be used to guide future planning and to support the development of a health information system for Europe. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  14. Wide disparity of clinical genetics services and EU rare disease research funding across Europe.

    PubMed

    Lynch, Sally Ann; Borg, Isabella

    2016-04-01

    The origins of clinical genetics services vary throughout Europe with some emerging from paediatric medicine and others from an academic laboratory setting. In 2011, the cross-border patients' rights directive recommended the creation of European Research Networks (ERNs) to improve patient care throughout EU. In 2013, the EU recommendation on the care for rare diseases came into place. The process of designating EU centres of expertise in rare diseases is being implemented to allow centres to enter ERNs. Hence, this is an opportune time to reflect on the current status of genetic services and research funding throughout Europe as 80 % of rare diseases have a genetic origin. Our aims were to determine (a) whether EU countries are prepared in terms of appropriate clinical genetic staffing to fulfil the European Union Committee of Experts on Rare Diseases (EUCERD) criteria that will allow national centres to be designated as centres of expertise, (b) which EU countries are successful in grant submissions to EU rare disease research funding and (c) country of origin of researchers from the EU presenting their research work as a spoken presentation at the European Society of Human Genetics annual conference. Our results show there is wide disparity of staffing levels per head of population in clinical genetics units throughout Europe. EU rare disease research funding is not being distributed equitably and the opportunity to present research is skewed with many countries not achieving spoken presentations despite abstract submissions. Inequity in the care of patients with rare diseases exists in Europe. Many countries will struggle to designate centres of expertise as their staffing mix and levels will not meet the EUCERD criteria which may prevent them from entering ERNs. The establishment of a small number of centres of expertise centrally, which is welcome, should not occur at the expense of an overall improvement in EU rare disease patient care. Caution should be

  15. Tunable Yellow-Red Photoluminescence and Persistent Afterglow in Phosphors Ca4LaO(BO3)3:Eu(3+) and Ca4EuO(BO3)3.

    PubMed

    Chen, Zhen; Pan, Yuexiao; Xi, Luqing; Pang, Ran; Huang, Shaoming; Liu, Guokui

    2016-11-07

    In most Eu(3+) activated phosphors, only red luminescence from the (5)D0 is obtainable, and efficiency is limited by concentration quenching. Herein we report a new phosphor of Ca4LaO(BO3)3:Eu(3+) (CLBO:Eu) with advanced photoluminescence properties. The yellow luminescence emitted from the (5)D1,2 states is not thermally quenched at room temperature. The relative intensities of the yellow and red emission bands depend strongly on the Eu(3+) doping concentration. More importantly, concentration quenching of Eu(3+) photoluminescence is absent in this phosphor, and the stoichiometric compound of Ca4EuO(BO3)3 emits stronger luminescence than the Eu(3+) doped compounds of CLBO:Eu; it is three times stronger than that of a commercial red phosphor of Y2O3:Eu(3+). Another beneficial phenomenon is that ligand-to-metal charge transfer (CT) transitions occur in the long UV region with the lowest charge transfer band (CTB) stretched down to about 3.67 eV (∼330 nm). The CT transitions significantly enhance Eu(3+) excitation, and thus result in stronger photoluminescence and promote trapping of excitons for persistent afterglow emission. Along with structure characterization, optical spectra and luminescence dynamics measured under various conditions as a function of Eu(3+) doping, temperature, and excitation wavelength are analyzed for a fundamental understanding of electronic interactions and for potential applications.

  16. Photoluminescence and thermoluminescence properties of Eu(2)(+) doped and Eu(2+) ,Dy(3)(+) co-doped Ba2 MgSi2 O7 phosphors.

    PubMed

    Sao, Sanjay Kumar; Brahme, Nameeta; Bisen, D P; Tiwari, Geetanjali

    2016-11-01

    In this work, we report the preparation, characterization, comparison and luminescence mechanisms of Eu(2)(+) -doped and Eu(2)(+) ,Dy(3)(+) -co-doped Ba2 MgSi2 O7 (BMSO) phosphors. Prepared phosphors were synthesized via a high temperature solid-state reaction method. All prepared phosphors appeared white. The phase structure, particle size, and elemental analysis were analyzed using X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX) analysis. The luminescence properties of the phosphors were investigated by thermoluminescence (TL) and photoluminescence (PL). The PL excitation and emission spectra of Ba2 MgSi2 O7 :Eu(2)(+) showed the peak to be around 381 nm and 490 nm respectively. The PL excitation spectrum of Ba2 MgSi2 O7 :Eu(2)(+) Dy(3)(+) showed the peak to be around 341 nm and 388 nm, and the emission spectrum had a broad band around 488 nm. These emissions originated from the 4f(6) 5d(1) to 4f(7) transition of Eu(2)(+) . TL analysis revealed that the maximum TL intensity was found at 5 mol% of Eu(2)(+) doping in Ba2 MgSi2 O7 phosphors after 15 min of ultraviolet (UV) light exposure. TL intensity was increased when Dy(3)(+) ions were co-doped in Ba2 MgSi2 O7 :Eu(2)(+) and maximum TL intensity was observed for 2 mol% of Dy(3)(+) . TL emission spectra of Ba1.95 MgSi2 O7 :0.05Eu(2)(+) and Ba1.93 MgSi2 O7 :0.05Eu(2)(+) ,0.02Dy(3)(+) phosphors were found at 500 nm. TL intensity increased with UV exposure time up to 15 min, then decreased for the higher UV radiation dose for both Eu doping and Eu,Dy co-doping. The trap depths were calculated to be 0.54 eV for Ba1.95 MgSi2 O7 :0.05Eu(2)(+) and 0.54 eV and 0.75 eV for Ba1.93 MgSi2 O7 :0.05Eu(2)(+) ,0.02Dy(3)(+) phosphors. It was observed that co-doping with small amounts of Dy(3)(+) enhanced the thermoluminescence properties of Ba2 MgSi2 O7 phosphor. Copyright © 2016 John Wiley & Sons, Ltd. [Correction added on 5 April 2016, after first online publication

  17. Luminescence Properties of GaN:Tb, GaN/AlGaN:Eu Superlattice, and AlN:Tb and Eu.

    NASA Astrophysics Data System (ADS)

    Lozykowski, H. J.; Jadwisienczak, W. M.; Brown, I. G.

    2001-03-01

    We report on recent progress in the investigation of cathodoluminescence (CL) of GaN doped with Tb, the visible photoluminescence (PL) and CL of GaN and Al_0.14Ga_0.86N /GaN superlattice doped with Eu, and the CL from AlN doped with Eu and Tb. The CL of GaN:Tb shows sharp emission lines corresponding to Tb^3+ ions transitions resolved in the spectral range from 350 nm to 750 nm, and observed over the temperature range of 7 - 330 K. The luminescence exhibits transitions which originate in the ^5D3 and ^5D4 levels and terminate in the ^7F manifolds. The depth resolved CL spectra analysis show a luminescence surface dead layer thickness of ~20 nm. The decay times for ^5D_3-->^7F5 (423.4nm) and ^5D_4-->^7F5 (551.6nm) transitions at 7 K are ~0.7 and ~1.8 ms, with little change with temperature. The visible PL and CL of GaN and Al_0.14Ga_0.86N/GaN superlattice doped with Eu ions, show sharp characteristic emission lines corresponding to Eu^3+ intra-4f^6-shell transitions. The luminescence shows dominant ^5D_0-->^7F_1,2,3 and weaker ^5D_0-->^7F_4,5,6 and ^5D_1-->^7F1 transitions. The intensity of Eu emission from Al_0.14Ga_0.86N/GaN superlattice annealed in N2 is ~58% stronger than from Eu in the GaN epilayer. Strong CL was observed from AlN thin single crystal films doped with Eu^3+ and Tb^3+ ions. The space group symmetry of the wurtzite AlN is C-P6_3mc and the Al cation occupies the site of point group symmetry C_3v. We assume that those implanted RE ions in AlN occupy relaxed substitutional Al-sites with hexagonal C_3v crystal symmetry. Emission lines corresponding to Eu^3+ and Tb^3+ intra-4f^n-shell transitions are resolved in the spectral range from 300 to 900 nm. The CL kinetics for several transitions of Eu^3+ (^5D_0), Tb^3+ (^5D_3,4) were analyzed. (Electronic mail: lozykows/@bobcat.ent.ohiou.edu)

  18. Improved optical photoluminescence by charge compensation in the phosphor system CaMoO 4:Eu 3+

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Lian, Hongzhou; Shi, Chunshan

    2007-08-01

    It has been found that charge compensated CaMoO4:Eu3+ phosphors show greatly enhanced red emission under 393 and 467 nm-excitation, compared with CaMoO4:Eu3+ without charge compensation. Two approaches to charge compensation, (a) 2Ca2+ → Eu3+ + M+, where M+ is a monovalent cation like Li+, Na+ and K+ acting as a charge compensator; (b) 3Ca2+ → 2Eu3+ + vacancy, are investigated. The influence of sintering temperature and Eu3+ concentration on the luminescent property of phosphor samples is also discussed.

  19. EuF3 nanotubes fabricated via Eu(NO3)3/cysteamine as precursor and their derived thermosensitive nanogels

    NASA Astrophysics Data System (ADS)

    Yang, Sen-sen; Song, Qiu-sheng; Gao, Kang; Wang, Hua-lin

    2014-08-01

    In this paper, we report a novel solution route to obtain rare earth nanotubes. Firstly, the complex of Eu(NO3)3/cysteamine (Eu-Complex) was used as the precursor, then nanotubes of EuF3 were fabricated from the precursor and NaF. Secondly, the EuF3 nanotubes reacted with acrylic acid (AA) and converted into vinyl decorated nanotubes. Finally, the decorated nanotubes copolymerized with N-isopropylacrylamide via free radical polymerization and thermosensitive EuF3 nanotubes/poly (N-isopropylacrylamide) (PNIPAm) nanogels were prepared. In order to investigate the mechanism to produce the nanotubes, the morphology structures of samples at different reaction stages were studied via TEM, and the formation mechanism of nanotubes is proposed. The chemical composition was confirmed by FTIR, XRD, XPS and elemental analyzer. The optical property of the as-prepared nanotubes and the nanogels was investigated in detail by photoluminescence (PL). The results suggest that, compared with their bulk counterparts, the nanogels present different thermosensitive fluorescence behavior, for instance, around their low critical solution temperature (LCST), the variation of PL emission intensity of the nanogels is slightly gentler.

  20. Nanoscale determinant to brighten up GaN:Eu red light-emitting diode: Local potential of Eu-defect complexes

    SciTech Connect

    Ishii, Masashi; Koizumi, Atsushi; Fujiwara, Yasufumi

    2015-04-21

    Emission sites in GaN:Eu red light-emitting diodes (LEDs) were investigated using a new spectroscopy technique, namely, site-selective pulse-driven emission spectroscopy (PDES). The PDES, in which the emission intensity of a pulse-driven LED is recorded with respect to the pulse frequency, revealed the charge-trapping dynamics of the Eu emission sites. We found that a determinant of the emission intensity of the sites was not their relative abundance, but rather the spatial extent of the local potential, which determines the effectiveness of the capture of injection charges. Minor sites with wider potentials enhanced the emission intensity of the LED, resulting in emission spectra that differ from those obtained using the photoluminescence of a GaN:Eu thin film. The potential curve is determined by the atomic structure of the complexes, which consist of a Eu dopant and nearby defects in the GaN host. The extent was characterized by a parameter, namely, cutoff frequency, and the emission sites with the wider and narrower potentials in the GaN:Eu LED were found to have cutoff frequencies of 400 kHz and 3 MHz, respectively. The cutoff frequency of 3 MHz was found to be the upper limit for emission sites in the LED. The emission site with the wider potential is useful for slower devices such as light fixtures, while the site with the narrower potential is useful for faster devices such as opto-isolators.

  1. Strong coupling between Eu2+ spins and Fe2As2 layers in EuFe1.9Co0.1As2 observed with NMR

    NASA Astrophysics Data System (ADS)

    Guguchia, Z.; Roos, J.; Shengelaya, A.; Katrych, S.; Bukowski, Z.; Weyeneth, S.; Murányi, F.; Strässle, S.; Maisuradze, A.; Karpinski, J.; Keller, H.

    2011-04-01

    A combination of x-ray diffraction, magnetization, and As75 nuclear magnetic resonance (NMR) experiments were performed on single-crystal EuFe1.9Co0.1As2. The strength of the hyperfine interaction between the As75 nuclei and the Eu2+ 4f states suggests a strong coupling between the Eu2+ moments and the Fe1.9Co0.1As2 layers. Such a strong interlayer coupling may be due to an indirect exchange interaction between the localized Eu2+ 4f moments, mediated by the Fe 3d conduction electrons. Magnetic susceptibility as well as As75-NMR measurements reveal a decrease of the SDW transition temperature to TSDW = 120 K as a result of Co doping. A change of the slope in the temperature dependence of the NMR frequency of the As75 lower-satellite line was observed at 225 K. At the same temperature also a change of the satellite line shape was found. These changes of the NMR spectra may be caused by the formation of a nematic phase below 225 K in EuFe1.9Co0.1As2.

  2. Interplay between magnetism and superconductivity in EuFe2-xCoxAs2 studied by 57Fe and 151Eu Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Błachowski, A.; Ruebenbauer, K.; Żukrowski, J.; Bukowski, Z.; Rogacki, K.; Moll, P. J. W.; Karpinski, J.

    2011-11-01

    The compound EuFe2-xCoxAs2 was investigated by means of 57Fe and 151Eu Mössbauer spectroscopy versus temperature (4.2-300 K) for x = 0 (parent), x = 0.34-0.39 (superconductor), and x = 0.58 (overdoped). It was found that the spin density wave (SDW) is suppressed by Co substitution; however, it survives in the region of superconductivity, but iron spectra exhibit some nonmagnetic components in the superconducting region. Europium orders magnetically, regardless of the cobalt concentration, with the spin reorientation from the a-axis in the parent compound toward the c-axis with increasing replacement of iron by cobalt. The reorientation takes place close to the a-c plane. Some trivalent europium appears in EuFe2-xCoxAs2 versus substitution due to the chemical pressure induced by Co atoms, and it experiences some transferred hyperfine field from Eu2+. Iron experiences some transferred field due to the europium ordering for substituted samples in the SDW and nonmagnetic state both, while the transferred field is undetectable in the parent compound. Superconductivity coexists with the 4f-europium magnetic order within the same volume. It seems that superconductivity has some filamentary character in EuFe2-xCoxAs2, and it is confined to the nonmagnetic component seen by the iron Mössbauer spectroscopy.

  3. A Eu/Tb-mixed MOF for luminescent high-temperature sensing

    NASA Astrophysics Data System (ADS)

    Wang, Huizhen; Zhao, Dian; Cui, Yuangjing; Yang, Yu; Qian, Guodong

    2017-02-01

    Temperature measurements and thermal mapping using luminescent MOF operating in the high-temperature range are of great interest in the micro-electronic diagnosis. In this paper, we report a thermostable Eu/Tb-mixed MOF Eu0.37Tb0.63-BTC-a exhibiting strong luminescence at elevated temperature, which can serve as a ratiometric luminescent thermometer for high-temperature range. The high-temperature operating range (313-473 K), high relative sensitivity and accurate temperature resolution, make such a Eu/Tb-mixed MOF useful for micro-electronic diagnosis.

  4. The electronic and optical properties of Eu/Si-codoped anatase TiO2 photocatalyst

    NASA Astrophysics Data System (ADS)

    Lin, Yanming; Jiang, Zhenyi; Hu, Xiaoyun; Zhang, Xiaodong; Fan, Jun

    2012-03-01

    The electronic and optical properties of Eu/Si-codoped anatase TiO2 are investigated using the density functional theory. The calculated results show that the synergistic effects of Eu/Si codoping can effectively extend the optical absorption edge, which can lead to higher visible-light photocatalytic activities than pure anatase TiO2. To verify the reliability of our calculated results, nanocrystalline Eu/Si-codoped TiO2 is prepared by a sol-gel-solvothermal method, and the experimental results also indicate that the codoping sample exhibits better absorption performance and higher photocatalytic activities than pure TiO2.

  5. Synthesis and characterization of Eu3+:YAG nanopowder by precipitation method

    NASA Astrophysics Data System (ADS)

    Balaji, D.; Thangaraju, D.; Durairajan, A.; Babu, S. Moorthy

    2013-02-01

    Eu3+:Y3Al5O12 (Eu3+:YAG) nanopowder has been synthesized by reverse co-precipitation method. Cubic YAG structure was obtained at 850 °C calcination. FE-SEM micrographs confirm that YAG:Eu3+ particles are homogeneous sphere like morphology with average particle size of 50-70 nm. The crystalline phosphors showed orange - red emission with magnetic dipole transition 5D0→7F1 (590 nm) as most prominent group than forced electric dipole transition 5D0→7F2 (610nm).

  6. Polymer thin films containing Eu(III) complex as lanthanide lasing medium

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yasuchika; Wada, Yuji; Yanagida, Shozo; Kawai, Hideki; Yasuda, Naoki; Nagamura, Toshihiko

    2003-10-01

    Direct evidence of lanthanide(III) lasing using Eu(III) complex in polymer thin films (threshold level <0.05 mJ) is reported. The thin film consists of polystyrene containing Eu(III) complexes based on two criteria: (1) Higher emission quantum yield of Eu(III) complexes, which increases the rs (energy density), and (2) faster radiation rate at large B (Einstein coefficient). The microcavity was constructed by coating a glass substrate with a film having a high refractive index. The film thickness was found to be 1.71 mm. The threshold level for laser transmission was found to be <0.05 mJ.

  7. Detection of Babesia EU1 in Ixodes ricinus ticks in northern Italy.

    PubMed

    Cassini, Rudi; Bonoli, Cristina; Montarsi, Fabrizio; Tessarin, Cinzia; Marcer, Federica; Galuppi, Roberta

    2010-07-15

    Babesia EU1, a potentially important emerging zoonotic pathogen, already detected in ticks and wild ruminants of different European Countries, was found in three pools of Ixodes ricinus nymphs in three different sites located in a single District of north-eastern Italy. Totally 356 ticks (60 pools) were collected from the environment during a surveillance activity in the year 2006. Babesia EU1 estimated individual tick prevalence in the area is 0.85%. The finding that also in northern Italy the tick population is carrying Babesia EU1 suggests a wide geographical spreading of this zoonotic pathogen in Europe. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  8. Red Afterglow Properties of Eu3+ in CaMoO4 Phosphor

    NASA Astrophysics Data System (ADS)

    Kang, Feng-Wen; Hu, Yi-Hua; Wu, Hao-Yi; Ju, Gui-Fang

    2011-10-01

    Eu3+ doped CaMoO4 phosphors were synthesized by using the solid state reaction method. The x-ray diffraction shows that all the patterns of the obtained samples are indexed to the sheelite structure. Red afterglow originating from the 5D0-7FJ (J = 0,1,2,3,4) transitions of Eu3+ was observed after the samples were excited by 254 nm and the optimal Eu3+ concentration in the CaMoO4 matrix was experimentally determined to be 0.50%. A possible explanation of this afterglow property is also discussed.

  9. Complex incommensurate helicoidal magnetic ordering of EuNiGe3

    NASA Astrophysics Data System (ADS)

    Ryan, D. H.; Cadogan, J. M.; Rejali, Rasa; Boyer, C. D.

    2016-07-01

    151Eu Mössbauer spectroscopy and neutron powder diffraction are combined to show that the tetragonal (I4mm #107) compound EuNiGe3 orders magnetically below {{T}\\text{N}}∼ 14 K and adopts a complex incommensurate helicoidal magnetic structure at 3.6 K, with a propagation vector \\mathbf{k}=≤ft[0.255(1),~0.054(14),~0\\right] and a Eu moment of 7.1(2) {μ\\text{B}} . On warming through 6 K an incommensurate sinusoidal modulation develops and dominates the magnetic order by 12 K.

  10. Inorganic scintillation detectors based on Eu-activated phosphors for 192Ir brachytherapy

    NASA Astrophysics Data System (ADS)

    Kertzscher, Gustavo; Beddar, Sam

    2017-06-01

    The availability of real-time treatment verification during high-dose-rate (HDR) brachytherapy is currently limited. Therefore, we studied the luminescence properties of the widely commercially available scintillators using the inorganic materials Eu-activated phosphors Y2O3:Eu, YVO4:Eu, Y2O2S:Eu, and Gd2O2S:Eu to determine whether they could be used to accurately and precisely verify HDR brachytherapy doses in real time. The suitability for HDR brachytherapy of inorganic scintillation detectors (ISDs) based on the 4 Eu-activated phosphors in powder form was determined based on experiments with a 192Ir HDR brachytherapy source. The scintillation intensities of the phosphors were 16-134 times greater than that of the commonly used organic plastic scintillator BCF-12. High signal intensities were achieved with an optimized packing density of the phosphor mixture and with a shortened fiber-optic cable. The influence of contaminating Cerenkov and fluorescence light induced in the fiber-optic cable (stem signal) was adequately suppressed by inserting between the fiber-optic cable and the photodetector a 25 nm band-pass filter centered at the emission peak. The spurious photoluminescence signal induced by the stem signal was suppressed by placing a long-pass filter between the scintillation detector volume and the fiber-optic cable. The time-dependent luminescence properties of the phosphors were quantified by measuring the non-constant scintillation during irradiation and the afterglow after the brachytherapy source had retracted. We demonstrated that a mixture of Y2O3:Eu and YVO4:Eu suppressed the time-dependence of the ISDs and that the time-dependence of Y2O2S:Eu and Gd2O2S:Eu introduced large measurement inaccuracies. We conclude that ISDs based on a mixture of Y2O3:Eu and YVO4:Eu are promising candidates for accurate and precise real-time verification technology for HDR BT that is cost effective and straightforward to manufacture. Widespread dissemination of this

  11. Lutetium-doped EuO films grown by molecular-beam epitaxy

    SciTech Connect

    Melville, A.; Heeg, T.; Mairoser, T.; Schmehl, A.; Shai, D. E.; Monkman, E. J.; Harter, J. W.; Hollaender, B.; Schubert, J.; Shen, K. M.; Mannhart, J.; Schlom, D. G.

    2012-05-28

    The effect of lutetium doping on the structural, electronic, and magnetic properties of epitaxial EuO thin films grown by reactive molecular-beam epitaxy is experimentally investigated. The behavior of Lu-doped EuO is contrasted with doping by lanthanum and gadolinium. All three dopants are found to behave similarly despite differences in electronic configuration and ionic size. Andreev reflection measurements on Lu-doped EuO reveal a spin-polarization of 96% in the conduction band, despite non-magnetic carriers introduced by 5% lutetium doping.

  12. Eu-doped 6LiF-SrF2 eutectic scintillators for neutron detection

    NASA Astrophysics Data System (ADS)

    Yanagida, Takayuki; Fukuda, Kentaro; Fujimoto, Yutaka; Kawaguchi, Noriaki; Kurosawa, Shunsuke; Yamazaki, Atsushi; Watanabe, Kenichi; Futami, Yoshisuke; Yokota, Yuui; Pejchal, Jan; Yoshikawa, Akira; Uritani, Akira; Iguchi, Tetsuo

    2012-03-01

    Eu2+ 0.05%, 0.1%, and 0.2% activated LiF-SrF2 eutectic scintillators were prepared by the Bridgman method using 6Li enriched (95%) raw material. The α-ray-induced radio luminescence spectra showed intense emission peak at 430 nm due to an emission from Eu2+ 5d-4f transition in the Eu:SrF2 layers. When excited by 252Cf neutrons, all the samples exhibited almost the same light yields of 5000-7000 ph/n with a typical decay times of several hundreds ns.

  13. Synthesis and luminescent properties of complexes of Eu(III) with 2-thienyltrifluoroacetonate, terephthalic acid and phenanthroline

    NASA Astrophysics Data System (ADS)

    Zhao, X. H.; Huang, K. L.; Jiao, F. P.; Liu, S. Q.; Liu, Z. G.; Hu, S. Q.

    2007-09-01

    This work reports the synthesis and luminescent properties of complexes of europium(III) with 2-thienyltrifluoroacetonate (HTTA), terephthalic acid (TPA) and phenanthroline (Phen), in the solid state. The new complexes were characterized by elemental analysis, infrared (IR) spectroscopy, scanning electronic microscopy (SEM) and thermal stability analysis. Both binuclear complex Eu2(TPA)(TTA)4Phen2 and polynuclear complex Eu(TPA)(TTA)Phen present better thermal stability than the mononuclear complex Eu(TTA)3Phen does. The formation of the binuclear/polynuclear structure of the complexes appears to be responsible for the enhancement of the thermal stability. The emission spectra show narrow emission bands that arise from the 5D0→7FJ (J=0 4) transition of the Eu3+ ion. The spectral data of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 present only one sharp peak in the region of the 5D0→7F0 transition indicating that only one Eu3+ ion species is present in each sample. In addition, the luminescence decay curves of the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 fit a single-exponential decay law. The values of quantum efficiencies of the emitting 5D0 level for the complexes Eu(TPA)(TTA)Phen and Eu2(TPA)(TTA)4Phen2 are 29% and 28%, respectively.

  14. Preparation and fluorescence property of red-emitting Eu{sup 3+}-activated amorphous calcium silicate phosphor

    SciTech Connect

    Kojima, Yoshiyuki; Kamei, Shinnosuke; Nishimiya, Nobuyuki

    2010-02-15

    This paper describes the energy efficient synthesis of a red-emitting Eu{sup 3+}-activated amorphous calcium silicate phosphor produced by heating a Eu{sup 3+}-activated calcium silicate hydrate phosphor. Concentration quenching of the Eu{sup 3+}-activated calcium silicate hydrate phosphor was not observed and the emission intensity did not decrease up to a Eu/(Ca+Eu) atomic ratio of 0.46. Heating of the Eu{sup 3+}-activated calcium silicate hydrate (Eu/(Ca+Eu) atomic ratio = 0.32) phosphor produced an amorphous Eu{sup 3+}-activated calcium silicate phosphor, which had a maximum emission intensity at 870 {sup o}C and emitted in the red under near-ultraviolet irradiation (395 nm). The emission intensity of the Eu{sup 3+}-activated amorphous calcium silicate phosphor was about half that of a commercial BaMgAl{sub 10}O{sub 17}:Eu{sup 2+} phosphor, and shows great potential for application in white light-emitting diodes.

  15. Synthesis and spectral characteristics of Sr 2Y 8(SiO 4) 6O 2: Eu polycrystals

    NASA Astrophysics Data System (ADS)

    Zuev, M. G.; Кarpov, A. M.; Shkvarin, А. S.

    2011-01-01

    Spectral-luminescent characteristics of Sr 2Y 8(SiO 4) 6O 2: Eu powder crystal phosphor with the apatite structure and high-intensity luminescence of Eu 3+ ions have been studied. The charge state of europium in the samples has been characterized by means of X-ray L 3-adsorption spectroscopy. It was established that Eu 3+ forms two types of optical centers. Besides, luminescence of Eu 2+ions was found. Reduction Eu 3+→Eu 2+ was considered, which may be due to VSr∥ vacancy formation in the 4 f crystal lattice position and to negative charge transfer by this vacancy to two EuY3+ ions. Thus, in the silicate lattice there exist inhomogeneously distributed oxygen-deficient centers, which are responsible for nonradiative transfer of excitation energy to Eu 3+ and Eu 2+ ions. To study electron-vibrational interactions in the crystal phosphor samples, their IR and Raman spectra were examined. In the luminescence spectrum of Eu 2+, a series of low-intensity bands caused by interaction of the 4 f65 d state of Eu 2+ with silicate lattice vibrations was observed.

  16. Composites of Eu(3+)-doped calcium apatite nanoparticles and silica particles: comparative study of two preparation methods.

    PubMed

    Isobe, Ayumu; Takeshita, Satoru; Isobe, Tetsuhiko

    2015-02-10

    We synthesized composites of Eu(3+)-doped calcium apatite (CaAp:Eu(3+)) nanoparticles and silica particles via two methods: (i) in situ synthesis of CaAp:Eu(3+) in the presence of silica particles and (ii) electrostatic adsorption of CaAp:Eu(3+) nanoparticles on silica particle surfaces. In both methods, submicrometer spherical silica particles were covered with CaAp:Eu(3+) nanoparticles without forming any impurity phases, as confirmed by X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. In method i, part of the silica surface acted as a nucleation site for apatite crystals and silica particles were inhomogeneously covered with CaAp:Eu(3+) nanoparticles. In method ii, positively charged CaAp:Eu(3+) nanoparticles were homogeneously adsorbed on the negatively charged silica surface through electrostatic interactions. The bonds between the silica surface and CaAp:Eu(3+) nanoparticles are strong enough not to break under ultrasonic irradiation, irrespective of the synthetic method used. The composite particles showed red photoluminescence corresponding to 4f → 4f transitions of Eu(3+) under near-UV irradiation. Although the absorption coefficient of the forbidden 4f → 4f transitions of Eu(3+) was small, the red emission was detectable with a commercial fluorescence microscope because the CaAp:Eu(3+) nanoparticles accumulated on the silica particle surfaces.

  17. Anomalous Hall effect in the prospective spintronic material Eu1-x Gd x O integrated with Si.

    PubMed

    Parfenov, Oleg E; Averyanov, Dmitry V; Tokmachev, Andrey M; Taldenkov, Alexander N; Storchak, Vyacheslav G

    2016-06-08

    Remarkable properties of EuO make it a versatile spintronic material. Despite numerous experimental and theoretical studies of EuO, little is known about the anomalous Hall effect in this ferromagnet. So far, the effect has not been observed in bulk EuO, though has been detected in EuO films with uncontrolled distribution of defects. In the present work doping is taken under control: epitaxial films of Gd-doped EuO are synthesized integrated with Si using molecular beam epitaxy and characterized with x-ray diffraction and magnetization measurements. Nanoscale transport studies reveal the anomalous Hall effect in the ferromagnetic region for samples with different Gd concentration. The saturated anomalous Hall effect conductivity value of 5.0 S·cm(-1) in Gd-doped EuO is more than an order of magnitude larger than those reported so far for Eu chalcogenides doped with anion vacancies.

  18. Synthesis and determination of the structural and optical characteristics of cBN micropowder with Eu{sup 3+} ions

    SciTech Connect

    Leonchik, S. V. Karotki, A. V.

    2013-10-15

    Cubic boron-nitride micropowder with Eu{sup 3+} ions (cBN:Eu) is synthesized under conditions of high pressures and temperatures. The structural, morphological, chemical, and optical characteristics of the cBN:Eu micropowder are studied using X-ray diffraction, energy-dispersive X-ray spectral microanalysis, photoluminescence, and optical transmission methods. It is found that the cBN:Eu lattice parameter is {approx}3.615 A. The intense red luminescence of the cBN:Eu micropowder (red glow), measured in the visible region of the spectrum in the range from 550 to 750 nm, is attributed to intracenter 4f-electron transitions of the Eu{sup 3+} ions. The possible nature of the cBN:Eu micropowder luminescence is discussed.

  19. Blue emission of YMO 4:Eu 2+ (M=V,P) nanocrystals prepared through facile wet process

    NASA Astrophysics Data System (ADS)

    Iwasaki, Mitsunobu; Yamashita, Naoki; Taguchi, Masato; Karuppucharmy, Subbian; Ito, Seishiro; Park, Wonkyu

    2006-08-01

    Nanometer-sized YPO 4:Eu and YVO 4:Eu particles were prepared from alkaline alcohol-water mixture with Y(NO 3) 3 6H IIO, EuCl 3 and H 3PO 4 (or NH 4VO 4) under reflux. The resultant particles were well crystallized ranging 10-50 nm in diameter by changing reaction conditions. Europium ions in YPO 4:Eu and YVO 4:Eu was successfully reduced to Eu 2+ ions by sodium borohydride under reflux. The peak position of blue emission due to Eu 2+ ions (4f-5d transition) in nanocrystals was different among the materials (Y IIO 3, YVO 4 and YPO 4).

  20. Abnormal Eu behavior at formation of H2O- and Cl-bearing fluids during degassing of granite magmas

    NASA Astrophysics Data System (ADS)

    Lukanin, Oleg

    2010-05-01

    One of the important features of REE behavior in the process of decompression degassing of granite melts is the presence of europium anomalies in REE spectrum of forming fluid phase. Negative Eu anomaly in REE spectrum of fluids enriched by chlorine that were formed under high pressures at early stages of degassing relative to REE spectrum of granite melts may take place. Negative Eu anomaly in fluid is replaced by positive one with pressure decrease and decline of Cl concentration in fluid [1, 2]. Observable unique features of europium redistribution between fluid and melt find an explanation in such a fact that Eu in contrast to the other REE under oxidation-reduction conditions, being typical for magmatic process, is present in acidic silica-alumina melts in two valency forms Eu3+ and Eu2+ whereas the dominant form for the other REE in such a melts is (REE)3+ [3, 4]. From the analysis of melt-fluid exchange reactions with participation of two valency forms of europium Eu3+ and Eu2+ follows that the total distribution coefficient of Eu between fluid and melt D(Eu)f-m is equal as a first approximation to [5, 6]: D(Eu)f-m = a1α [C(Cl)f]3 + a2 (1 - α)[C(Cl)f]2, where C(Cl)f - the concentration of Cl in fluid, α = Eu3+/(Eu3+ + Eu2+), i.e. fraction of Eu3+ from the general amount of europium in the melt, and, a1anda2- constants that can be approximately estimated from empirical data upon Eu fluid/melt distribution. The equation given allows to estimate the influence of oxidizing condition of europium on sign and size of Eu anomaly, which is expressed by Eu/Eu# ratio, where Eu is real concentration of europium in fluid being in equilibrium with melt with constant Eu3+/(Eu3+ + Eu2+) ratio, and Eu# is possible "virtual" concentration of europium that could be in the same fluid provided that all europium as other REE as well were exclusively present in trivalent form. The sign and size of Eu anomaly in fluid depends upon Cl concentration in fluid and Eu3+/Eu2+ ratio in