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Sample records for impaired pmn migratory

  1. Phytoplankton Monitoring Network (PMN)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Phytoplankton Monitoring Network (PMN) is a part of the National Centers for Coastal Ocean Science (NCCOS). The PMN was created as an outreach program to connect...

  2. Impairment of adenosine A3 receptor activity disrupts neutrophil migratory capacity and impacts innate immune function in vivo.

    Science.gov (United States)

    Butler, Matt; Sanmugalingam, Devika; Burton, Victoria J; Wilson, Tammy; Pearson, Ruth; Watson, Robert P; Smith, Philip; Parkinson, Scott J

    2012-12-01

    Adenosine possesses potent anti-inflammatory properties which are partly mediated by G(i) -coupled adenosine A3 receptors (A3Rs). A3R agonists have shown clinical benefit in a number of inflammatory conditions although some studies in A3R-deficient mice suggest a pro-inflammatory role. We hypothesised that, in addition to cell signalling effects, A3R compounds might inhibit neutrophil chemotaxis by disrupting the purinergic feedback loop controlling leukocyte migration. Human neutrophil activation triggered rapid upregulation of surface A3R expression which was disrupted by pre-treatment with either agonist (Cl-IB-MECA) or antagonist (MRS1220). Both compounds reduced migration velocity and neutrophil transmigration capacity without impacting the response to chemokines per se. Similar effects were observed in murine neutrophils, while cells from A3R-deficient mice displayed a constitutively impaired migratory phenotype indicating compound-induced desensitisation and genetic ablation had the same functional outcome. In a dextran sodium sulphate-induced colitis model, A3R-deficient mice exhibited reduced colon pathology and decreased tissue myeloperoxidase levels at day 8 - consistent with reduced neutrophil recruitment. However, A3R-deficient mice were unable to resolve the dextran sodium sulphate-induced inflammation and had elevated numbers of tissue-associated bacteria by day 21. Our data indicate that A3Rs play a role in neutrophil migration and disrupting this function has the potential to adversely affect innate immune responses.

  3. Dry etching of single crystal PMN-PT piezoelectric material.

    OpenAIRE

    Agnus, Joël; Alexandru Ivan, Ioan; Queste, Samuel

    2011-01-01

    International audience; During the last decade, the applications of PMN-PT spread significantly. Unlike PZT, the appropriate microtechnologies for PMN-PT Piezo-MEMS aren't fully documented in the literature. This paper deals with the PMN-PT etching by inductively coupled plasma (ICP) technique, also known as DRIE. The paper quantitatively presents the etching parameters of PMN-PT by the Ar/C4F8 gas combination and reports some related useful experience.

  4. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia.

    Science.gov (United States)

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-12-15

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens.

  5. Ceramics like PZT-PMN; Ceramicas do tipo PZT-PMN

    Energy Technology Data Exchange (ETDEWEB)

    Droescher, R.E.; Sousa, V.C. [Universidade Federal do Rio Grande do Sul (LABIOMAT/DEMAT/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais. Lab. de Biomateriais; Bergman, C.P. [Universidade Federal do Rio Grande do Sul (LACER/DEMAT/UFRGS), Porto Alegre, RS (Brazil). Dept. de Materiais. Lab. de Ceramicas Avancadas

    2009-07-01

    The goal of this work was to achieve piezoelectric ceramics referring to the system PZT-PMN Pb(Mg{sub 1}/{sub 3}Nb{sub 2}/{sub 3}Zr{sub 0},{sub 52}Ti{sub 0},{sub 48})O{sub 3} . Have been analysed ceramics like 0,65PZT-0,35PMN ((Pb(Mg{sub 0},{sub 1167}Nb{sub 0},{sub 2300}Zr{sub 0},{sub 3380}Ti{sub 0},{sub 3120})O{sub 3}), 0,75PZT-0,25PMN ((Pb(Mg{sub 0},{sub 083}Nb{sub 0}.{sub 1675}Zr{sub 0},{sub 3900}Ti{sub 0},{sub 3600})O3) and the 0,85PZT-0,15PMN ((Pb(Mg{sub 0,0500}Nb{sub 0},{sub 1000}Zr{sub 0},{sub 4420}Ti{sub 0},{sub 4080})O{sub 3}). The influence of the calcination and concentration of PZT on the lattice phases, microstructure and density was evaluated. Then, the method used was the mixed-oxide method, the samples were taken under different temperatures of calcination before the final sinterizing. The DRX and SEM techniques were used to identify the phases formed and analyse the microstructure, respectively. The main result revealed that, the better way is to realize three burns before the final sinterizing at 1200 o C/4 h . Like that, on obtain for sure the average lattice phases, like: perovskite, pyrochlore and PbO and also tend to densify the samples. (author)

  6. PMN-PT/PVDF Nanocomposite for High Output Nanogenerator Applications

    Directory of Open Access Journals (Sweden)

    Chuan Li

    2016-04-01

    Full Text Available The 0.7Pb(Mg1/3Nb2/3O3-0.3PbTiO3(0.7PMN-0.3PT nanorods were obtained via hydrothermal method with high yield (over 78%. Then, new piezoelectric nanocomposites based on (1−xPb(Mg1/3Nb2/3O3-xPbTiO3 (PMN-PT nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride (PVDF polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young’s modulus of nanocomposites were enhanced as compared to that of the pure PVDF. The largest Young’s modulus of 1.71 GPa was found in the samples with 20 wt % nanorod content. The maximum output voltage of 10.3 V and output current of 46 nA were obtained in the samples with 20 wt % nanorod content, which was able to provide a 13-fold larger output voltage and a 4.5-fold larger output current than that of pure PVDF piezoelectric polymer. The current density of PMN-PT/PVDF nanocomposites is 20 nA/cm2. The PMN-PT/PVDF nanocomposites exhibited great potential for flexible self-powered sensing applications.

  7. PMN-PT/PVDF Nanocomposite for High Output Nanogenerator Applications.

    Science.gov (United States)

    Li, Chuan; Luo, Wenbo; Liu, Xingzhao; Xu, Dong; He, Kai

    2016-04-11

    The 0.7Pb(Mg1/3Nb2/3)O₃-0.3PbTiO₃(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1-x)Pb(Mg1/3Nb2/3)O₃-xPbTiO₃ (PMN-PT) nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride) (PVDF) polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young's modulus of nanocomposites were enhanced as compared to that of the pure PVDF. The largest Young's modulus of 1.71 GPa was found in the samples with 20 wt % nanorod content. The maximum output voltage of 10.3 V and output current of 46 nA were obtained in the samples with 20 wt % nanorod content, which was able to provide a 13-fold larger output voltage and a 4.5-fold larger output current than that of pure PVDF piezoelectric polymer. The current density of PMN-PT/PVDF nanocomposites is 20 nA/cm². The PMN-PT/PVDF nanocomposites exhibited great potential for flexible self-powered sensing applications.

  8. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods

    Science.gov (United States)

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-02-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V.

  9. Optimal conservation of migratory species.

    Directory of Open Access Journals (Sweden)

    Tara G Martin

    Full Text Available BACKGROUND: Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea-regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity bringing into question the utility and efficiency of current conservation efforts. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. CONCLUSIONS/SIGNIFICANCE: We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of

  10. Regional migratory osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Cahir, John G. [Department of Radiology, Norfolk and Norwich University Hospital, Colney Lane, Norwich, Norfolk NR4 7UY (United Kingdom)], E-mail: john.cahir@nnuh.nhs.uk; Toms, Andoni P. [Department of Radiology, Norfolk and Norwich University Hospital, Colney Lane, Norwich, Norfolk NR4 7UY (United Kingdom)

    2008-07-15

    Regional migratory osteoporosis (RMO) is an uncommon disease characterised by a migrating arthralgia involving the weight bearing joints of the lower limb. The typical imaging findings on radiographs, magnetic resonance imaging, computed tomography and bone scintigraphy are described and illustrated. Men in their fifth and sixth decades of life are most commonly affected. The most common presentation is with proximal to distal spread in the lower limb. The world literature has been reviewed which has revealed 63 documented cases of regional osteoporosis or bone marrow oedema with migratory symptoms. Most of these cases have not been labelled as RMO and therefore the condition is probably under-diagnosed. The radiology of RMO is indistinguishable from transient osteoporosis of the hip (TOH) except for the migratory symptoms and the two conditions are likely to be part of the same spectrum of disease. Systemic osteoporosis is a more recently recognised accompanying feature that hints at an underlying aetiology and an approach to the management of this condition.

  11. PMN-PT nanowires with a very high piezoelectric constant.

    Science.gov (United States)

    Xu, Shiyou; Poirier, Gerald; Yao, Nan

    2012-05-09

    A profound way to increase the output voltage (or power) of the piezoelectric nanogenerators is to utilize a material with higher piezoelectric constants. Here we report the synthesis of novel piezoelectric 0.72Pb(Mg(1/3)Nb(2/3))O(3)-0.28PbTiO(3) (PMN-PT) nanowires using a hydrothermal process. The unpoled single-crystal PMN-PT nanowires show a piezoelectric constant (d(33)) up to 381 pm/V, with an average value of 373 ± 5 pm/V. This is about 15 times higher than the maximum reported value of 1-D ZnO nanostructures and 3 times higher than the largest reported value of 1-D PZT nanostructures. These PMN-PT nanostructures are of good potential being used as the fundamental building block for higher power nanogenerators, high sensitivity nanosensors, and large strain nanoactuators.

  12. Design, production and testing of PMN-PT electrostrictive transducers.

    Science.gov (United States)

    Coutte, J; Dubus, B; Debus, J C; Granger, C; Jones, D

    2002-05-01

    Lead magnesium niobate ceramics (PMN) are promising materials for application in the field of high power transducers. The advantage of PMN materials are the large strains generated under moderate electric field and the low hysteresis. The electrostrictive effect is non-linear, the corresponding physical constants depend on temperature and frequency and a DC electrical bias is required. These difficulties must be considered at the design stage. A finite element model has been developed and validated in the ATILA code for non-linear static and time-domain analyses. These numerical modelings are used to design and test two Langevin-type electrostrictive transducers. The first transducer is made of PMN-PT-La (90-10-1%) ceramics (TRS Ceramics), the second one of ESCI ceramics (Morgan Matroc). For given static mechanical prestresses, resonance frequencies and effective coupling coefficients are measured at different DC electric fields and temperatures.

  13. Misfit strain phase diagrams of epitaxial PMN-PT films

    Science.gov (United States)

    Khakpash, N.; Khassaf, H.; Rossetti, G. A.; Alpay, S. P.

    2015-02-01

    Misfit strain-temperature phase diagrams of three compositions of (001) pseudocubic (1 - x).Pb (Mgl/3Nb2/3)O3 - x.PbTiO3 (PMN-PT) thin films are computed using a phenomenological model. Two (x = 0.30, 0.42) are located near the morphotropic phase boundary (MPB) of bulk PMN-PT at room temperature (RT) and one (x = 0.70) is located far from the MPB. The results show that it is possible to stabilize an adaptive monoclinic phase over a wide range of misfit strains. At RT, the stability region of this phase is much larger for PMN-PT compared to barium strontium titanate and lead zirconate titanate films.

  14. Electrical behaviour of PMN-PT-PVDF nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Shrabanee; Mishra, S K [MST Division, National Metallurgical Laboratory, Jamshedpur 834007 (India)], E-mail: shrabaneesen@yahoo.co.in

    2008-08-21

    Nanocomposites of polyvinyldene fluoride (PVDF) and a solid solution of lead magnesium niobate and lead titanate (0.65PMN-0.35PT) with varying composition ratios were prepared by the hot-press technique. The phase structure and morphology were studied by thermal analysis (DTA), x-ray diffraction and scanning electron microscopy. The PVDF sample showed an exothermic peak due to the crystallization of the PVDF phase, but with the addition of PMN-PT powders an extra peak appeared due to the crystallization of the pyrochlore phase present in the PMN-PT powder. The crystallite size of the prepared samples was found to be between 40 and 60 nm. The value of the relative permittivity increased with the increase in the ceramic concentration. The presence of a single semicircle confirmed the presence of the bulk effect only. The bulk conductivity indicated an Arrhenius type thermally activated process. The ac conductivity spectrum obeyed the Jonscher power law.

  15. Design and fabrication of PIN-PMN-PT single-crystal high-frequency ultrasound transducers.

    Science.gov (United States)

    Sun, Ping; Zhou, Qifa; Zhu, Benpeng; Wu, Dawei; Hu, Changhong; Cannata, Jonathan M; Tian, Jin; Han, Pengdi; Wang, Gaofeng; Shung, K Kirk

    2009-12-01

    High-frequency PIN-PMN-PT single crystal ultrasound transducers at center frequencies of 35 MHz and 60 MHz were successfully fabricated using lead indium niobate-lead magnesium niobate-lead titanate (0.23PIN- 0.5PMN-0.27PT) single crystal. The new PIN-PMN-PT single crystal has higher coercivity (6.0 kV/cm) and higher Curie temperature (160 degrees C) than PMN-PT crystal. Experimental results showed that the PIN-PMN-PT transducers have similar performance but better thermal stability compared with the PMN-PT transducers.

  16. Growth and Characterization on PMN-PT-Based Single Crystals

    Directory of Open Access Journals (Sweden)

    Jian Tian

    2014-07-01

    Full Text Available Lead magnesium niobate—lead titanate (PMN-PT single crystals have been successfully commercialized in medical ultrasound imaging. The superior properties of PMN-PT crystals over the legacy piezoelectric ceramics lead zirconate titanate (PZT enabled ultrasound transducers with enhanced imaging (broad bandwidth and improved sensitivity. To obtain high quality and relatively low cost single crystals for commercial production, PMN-PT single crystals were grown with modified Bridgman method, by which crystals were grown directly from stoichiometric melt without flux. For ultrasound imaging application, [001] crystal growth is essential to provide uniform composition and property within a crystal plate, which is critical for transducer performance. In addition, improvement in crystal growth technique is under development with the goals of improving the composition homogeneity along crystal growth direction and reducing unit cost of crystals. In recent years, PIN-PMN-PT single crystals have been developed with higher de-poling temperature and coercive field to provide improved thermal and electrical stability for transducer application.

  17. Superoxide Radical Formation in Isolated PMN from Experimental Vaginal Trichomoniasis

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    Z Valadkhani

    2006-06-01

    Full Text Available Trichomoniasis, the most widespread sexually transmitted disease is caused by Trichomonas vaginalis. This parasite is site specific for the genitourinary tract and recruitment of macrophages as well as polymorphonuclear nutrophils (PMN to the site of infection is the first line of defense as a component of non-specific resistance and immunity. In this study, BALB/c mice were infected with 10 isolates from symptomatic and 10 from asymptomatic patients. Then PMN from vaginal washes, vaginal tissue and blood of infected mice was isolated and the rate of superoxide formation by intact stimulated PMN was measured. Results showed that, mice infected with symptomatic isolates indicated significant increase in polymorphs with increase in days of infection as compared with mice infected with asymptomatic isolate and control (uninfected animals. Vaginal tissue cells generated maximal amount of superoxide in symptomatic isolates infected animals (5.17 ± 0.36 as compared to asymptomatic isolates (4.54 ± 0.43, which brings out the maximal abnormality in PMN in this localized area. The amount of superoxide radicals generated by cells of vaginal washes and blood of symptomatic isolate infected mice 4.29 ± 0.25 and 2.16 ± 0.35 was less than the asymptomatic isolate (4.94 ± 0.49 and 3.18 ± 0.26, respectively. This study indicates that super oxide radical generation may play role in establishing the infection.

  18. Magnetoelectric effect in FeCo/PMN-PT/FeCo trilayers prepared by electroless deposition of FeCo on PMN-PT crystals with various orientations

    Energy Technology Data Exchange (ETDEWEB)

    Shen, H.Q.; Wang, Y.G., E-mail: yingang.wang@nuaa.edu.cn; Xie, D.; Cheng, J.H.

    2014-10-15

    Highlights: • The composites FeCo/PMN-PT/FeCo were prepared by electroless deposition. • The influence of the crystal cut of PMN-PT on ME coupling is discussed. • Optimizing the crystal cut of the piezoelectric substrate, proper resonant frequency and ME effect could be obtained. - Abstract: The magnetoelectric (ME) effect was studied in the FeCo/PMN-PT/FeCo trilayer composites prepared by electroless deposition of the FeCo layers on the single crystal PMN-PT substrates with various crystal cuts. X-ray diffraction reveals that the orientation of PMN-PT substrate has no effect on the growth of FeCo layer. The structures with PMN-PT crystals of various orientations have different acoustic resonance frequencies. FeCo/PMN-PT/FeCo composites with PMN-PT of 〈0 0 1〉{sup L} × 〈01{sup ‾}1〉{sup W} × 〈0 1 1〉{sup T} crystal cut shows superior ME performance, which is due to the highest piezoelectric module of PMN-PT.

  19. Design and Fabrication of PIN-PMN-PT Single-Crystal High-Frequency Ultrasound Transducers

    OpenAIRE

    Sun, Ping; Zhou, Qifa; Zhu, Benpeng; WU, DAWEI; Hu, Changhong; Cannata, Jonathan M.; Tian, Jin; Han, Pengdi; Wang, Gaofeng; Shung, K. Kirk

    2009-01-01

    High-frequency PIN-PMN-PT single crystal ultrasound transducers at center frequencies of 35 MHz and 60 MHz were successfully fabricated using lead indium niobate-lead magnesium niobate-lead titanate (0.23PIN-0.5PMN-0.27PT) single crystal. The new PIN-PMN-PT single crystal has higher coercivity (6.0 kV/cm) and higher Curie temperature (160°C) than PMN-PT crystal. Experimental results showed that the PIN-PMN-PT transducers have similar performance but better thermal stability compared with the ...

  20. 75 FR 53774 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Science.gov (United States)

    2010-09-01

    ... Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain...-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain..., Interior. ACTION: Final rule. SUMMARY: This rule prescribes special early-season migratory bird...

  1. NMR study of size effects in relaxor PMN nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Blinc, Robert [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Zalar, Bostjan; Zupancic, Blaz [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); EN-FIST Centre of Excellence, Dunajska cesta 156, 1000 Ljubljana (Slovenia); Morozovska, Anna N. [Institute for Problems of Material Science, National Academy of Sciences of Ukraine, Krjijanovskogo 3, 03142 Kiev (Ukraine); V. Lashkarev Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, prospekt Nauki 41, 03028 Kiev (Ukraine); Glinchuk, Maya D. [Institute for Problems of Material Science, National Academy of Sciences of Ukraine, Krjijanovskogo 3, 03142 Kiev (Ukraine)

    2011-11-15

    {sup 93}Nb 1/2{yields} -1/2 NMR line shape and spin-lattice measurements show that microcrystalline PbMg{sub 1/3}Nb{sub 2/3}O{sub 3} (PMN) powder is dynamically disordered at room temperature, whereas nanocrystalline PMN powder is orientationally frozen out and long-range ordered at room temperature. The dynamical disorder of the microcrystalline powder results in a motional averaging of the anisotropic part of the {sup 93}Nb chemical shift tensor and second order quadrupole shift, whereas this averaging is absent in the nanocrystalline powder, resulting in a broader central line and a longer spin-lattice relaxation time. This seems to be the first observation of such size effects in a relaxor. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Frequency dispersion of flexoelectricity in PMN-PT single crystal

    Directory of Open Access Journals (Sweden)

    Longlong Shu

    2017-01-01

    Full Text Available The mechanism of the recent discovered enhanced flexoelectricity in perovskites has brought about numerous controversies which still remain unclear. In this paper, we employed relaxor 0.68Pb(Mg2/3Nb1/3O3 -0.32PbTiO3 (PMN-PT single crystals for study. The observed flexoelectric coefficient in PMN-PT single crystal reaches up to 100 μC/m, and in a relative low frequency range, exhibits an abnormal frequency dispersion phenomenon with a positive relationship with frequency. Such frequency dispersion regulation is different from the normal relaxation behavior that usually occur a time delay, and hence proves the flexoelectricity acting more like bulk effect rather than surface effect in this kind of materials.

  3. High-performance PMN-PT thick films.

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    Kosec, Marija; Ursic, Hana; Holc, Janez; Hrovat, Marko; Kuscer, Danjela; Malic, Barbara

    2010-10-01

    This article describes some of our work on ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃ (0.65PMN-0.35PT) thick films printed on alumina substrates. These thick films, with the nominal composition ₀.₆₅Pb(Mg₁/₃Nb(₂/₃)O₃-₀.₃₅PbTiO₃, were produced by screen-printing and firing a paste prepared from an organic vehicle and pre-reacted fine particles of avery chemically homogeneous powder. To improve the adhesion of the 0.65PMN-0.35PT to the platinized alumina substrate,a Pb(Zr₀.₅₃Ti₀.₄₇)O₃ layer was deposited between the electrode and the substrate. The samples were then sintered at 950 °C for 2 h with various amounts of packing powder on the alumina (Al₂O₃) substrates. The sintering procedure was optimized to obtain dense 0.65PMN-0.35PT films. The films were then characterized using scanning electron microscopy as well as measurements of the dielectric and piezoelectric constants.The electrostrictive behavior of the 0.65PMN-0.35PT thick films was investigated using an atomic force microscope(AFM). Finally, substrate-free, large-displacement bending type actuators were prepared and characterized, and the normalized displacement (i.e., the displacement per unit length) of the actuators was determined to be 55 μm/cm at 3.6 kV/cm.

  4. Revolutionary non-migratory migrants

    OpenAIRE

    Jonker, M. R.

    2011-01-01

    In the migratory behaviour of the Barnacle Goose Branta leucopsis several changes have occurred over the past few decades. Barnacle geese breeding in Russia have delayed the commencement of spring migration with approximately one month since the 1980s, new populations have emerged in former stopover areas in the Baltic Sea region, and a non-migratory population has emerged in the wintering area in The Netherlands. This thesis aims to understand these changes. First, I studied the delay in com...

  5. Impaired neutrophils in children with the typical form of hemolytic uremic syndrome.

    Science.gov (United States)

    Fernández, Gabriela C; Gómez, Sonia A; Rubel, Carolina J; Bentancor, Leticia V; Barrionuevo, Paula; Alduncín, Marta; Grimoldi, Irene; Exeni, Ramón; Isturiz, Martín A; Palermo, Marina S

    2005-09-01

    Experimental and clinical evidence suggest that activated neutrophils (PMN) could contribute to endothelial damage in Hemolytic Uremic Syndrome (D+HUS). Additionally, while PMN-activating cytokines and PMN-derived products have been found in D+HUS sera, we have demonstrated phenotypic alterations in D+HUS PMN compatible with a deactivation state. Here, we investigated whether D+HUS PMN were actually hyporesponsive, and explored some of the mechanisms probably involved in their derangement. Twenty-two D+HUS children were bled in the acute period, and blood samples from healthy, acute uremic and neutrophilic children were obtained as controls. We evaluated degranulation markers in response to cytokines, intracellular granule content, and reactive oxygen species (ROS) generation in circulating D+HUS and control PMN. The influence of D+HUS-derived plasma and the direct effects of Stx in vitro were evaluated on healthy donors' PMN. We found that D+HUS PMN presented reduced degranulatory capacity in response to cytokines and intracellular granule content, and decreased ROS generation. D+HUS plasma or Stx did not affect the phenotype and function of healthy donors' PMN. These results suggest that upon hospitalization D+HUS PMN are functionally impaired and show features of previous degranulation, indicating a preceding process of activation with release of ROS and proteases involved in endothelial damage.

  6. Colloidal processing of PMN-PT thick films for piezoelectric sensor applications

    Science.gov (United States)

    Luo, Hongyu

    65%Pb(Mg1/3Nb2/3)O3-35%PbTiO3 (65PMN-35PT, or PMN-PT) is a highly piezoelectric ceramic with superior piezoelectric coefficients over the more popular Pb(Zr0.5Ti0.5)O 3 (PZT). Because of its complex chemistry and high volatility of lead above 1000°C, the perovskite phase of PMN-PT is hard to process and has prevented PMN-PT from various piezoelectric applications, especially in the new area of piezoelectric micro-electro-mechanical systems (PMEMS) involving thick or thin piezoelectric films. In this thesis, a novel precursor suspension method is introduced that substantially lowers the sintering temperature of PMN-PT to 850°C from a PMN precursor powder made by coating Mg(OH) 2 on Nb2O5 particles. The precursor suspension method entails suspending PMN powders in PT precursor and uses the reaction sintering capability of PMN with nano-sized PT in the temperature range of 800°C˜1000°C. Moreover, free-standing PMN-PT thick films were obtained by tape casting the PMN-PT powder. This new geometry of PMN-PT shows giant electric-field enhanced piezoelectric responses comparable with those of single crystals. As an example of application, the PMN-PT thick film is bonded to a thinner layer of copper by electroplating and made into piezoelectric cantilever sensors. In conclusion, the colloidal suspension processing method produces free-standing PMN-PT thick films with ultrahigh piezoelectric properties.

  7. Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

    Science.gov (United States)

    Boyle, T.J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

  8. Tip-bias-induced domain evolution in PMN-PT transparent ceramics via piezoresponse force microscopy

    Science.gov (United States)

    Zhao, K. Y.; Zhao, W.; Zeng, H. R.; Yu, H. Z.; Ruan, W.; Xu, K. Q.; Li, G. R.

    2015-05-01

    Piezoresponse force microscopy (PFM) was employed to investigate ferroelectric domain structures and their dynamic behavior of lead magnesium niobate-lead titanate [Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)] transparent ceramics under an tip-bias-induced electric field. A remarkable effect of fluctuation of PT content on the domain configurations and domain dynamic response in PMN-PT transparent ferroelectric ceramics were found by PFM. Comparing with PMN-10%PT and PMN-20%PT, the reversed polarization of macrodomain area in PMN-35%PT and PMN-25%PT exhibits a relatively higher response behavior and better polarization retention performance under the PFM tip-bias-induced electric field, which correspond to their unique macroscopic electro-optic properties.

  9. The Strength of PIN-PMN-PT Single Crystals under Bending with a Longitudinal Electric Field

    Science.gov (United States)

    2011-04-06

    The strength of PIN– PMN – PT single crystals under bending with a longitudinal electric field This article has been downloaded from IOPscience. Please...COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE The Strength Of PIN- PMN - PT Single Crystals Under Bending With A Longitudinal Electric Field... PMN ? PT ) single crystals was measured using a four point bending apparatus with a longitudinal electric field applied to the bar during bending. The

  10. 76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

    Science.gov (United States)

    2011-06-03

    ... Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by the Armed Forces AGENCY: Fish and... birds during approved military readiness activities without violating the Migratory Bird Treaty Act... the Armed Forces to incidentally take migratory birds. The Authorization Act also stated that...

  11. 76 FR 48693 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2011-08-08

    ... August 8, 2011 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded... RIN 1018-AX34 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain...

  12. 77 FR 29515 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2012-05-17

    ... Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2012-13... RIN 1018-AX97 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting... in an earlier document to establish annual hunting regulations for certain migratory game birds...

  13. 75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2010-08-06

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands for the 2010-11...

  14. Features of dielectric response in PMN-PT ferroelectric ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, J D S [Grupo de Ferroeletricos e Materiais Multifuncionais, Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia-MG (Brazil); Araujo, E B; Guarany, C A; Reis, R N; Lima, E C [Grupo Ferroeletricos e Novos Materiais, Departamento de Fisica e Quimica, Universidade Estadual Paulista, 15385-000 Ilha Solteira-SP (Brazil)], E-mail: santos@dfq.feis.unesp.br

    2008-11-21

    In this paper, electrical and structural properties were reported for pyrochlore free (1 - x)[Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}] - xPbTiO{sub 3} (PMN-PT) (with 35 mol% PbTiO{sub 3}) ceramics obtained from fine powders. Dielectric studies were focused on the investigation of the complex dielectric permittivity ({epsilon}' - i{epsilon}'') as a function of frequency and temperature. The effects of the dc applied electric field on dielectric response were also investigated. Results revealed a field dependence dielectric anomaly in the dielectric permittivity curves ({epsilon}(T)) in the low dc electric field region, which in turn prevails in the whole analysed frequency interval. To the best of our knowledge, these properties for the PMN-PT ceramic system have not been reported before as in this work. The results were analysed within the framework of the current models found in the literature.

  15. Modeling the Geography of Migratory Pathways and Stopover Habitats for Neotropical Migratory Birds

    OpenAIRE

    Roger Tankersley, Jr.; Kenneth Orvis

    2003-01-01

    Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixe...

  16. Revolutionary non-migratory migrants

    NARCIS (Netherlands)

    Jonker, M.R.

    2011-01-01

    In the migratory behaviour of the Barnacle Goose Branta leucopsis several changes have occurred over the past few decades. Barnacle geese breeding in Russia have delayed the commencement of spring migration with approximately one month since

  17. Revolutionary non-migratory migrants

    NARCIS (Netherlands)

    Jonker, M.R.

    2011-01-01

    In the migratory behaviour of the Barnacle Goose Branta leucopsis several changes have occurred over the past few decades. Barnacle geese breeding in Russia have delayed the commencement of spring migration with approximately one month since

  18. Revolutionary non-migratory migrants

    NARCIS (Netherlands)

    Jonker, M.R.

    2011-01-01

    In the migratory behaviour of the Barnacle Goose Branta leucopsis several changes have occurred over the past few decades. Barnacle geese breeding in Russia have delayed the commencement of spring migration with approximately one month since

  19. Optical properties of PMN-PT thin films prepared using pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tong, X.L., E-mail: tongxinglin@yahoo.com.cn [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China); Lin, K.; Lv, D.J.; Yang, M.H.; Liu, Z.X.; Zhang, D.S. [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China)

    2009-06-30

    (1 - x)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3} (PMN-PT) thin films have been deposited on quartz substrates using pulsed laser deposition (PLD). Crystalline microstructure of the deposited PMN-PT thin films has been investigated with X-ray diffraction (XRD). Optical transmission spectroscopy and Raman spectroscopy are used to characterize optical properties of the deposited PMN-PT thin films. The results show that the PMN-PT thin films of perovskite structure have been formed, and the crystalline and optical properties of the PMN-PT thin films can be improved as increasing the annealing temperature to 750 deg. C, but further increasing the annealing temperature to 950 deg. C may lead to a degradation of the crystallinity and the optical properties of the PMN-PT thin films. In addition, a weak second harmonic intensity (SHG) has been observed for the PMN-PT thin film formed at the optimum annealing temperature of 750 deg. C according to Maker fringe method. All these suggest that the annealing temperature has significant effect on the structural and optical properties of the PMN-PT thin films.

  20. Diffuse Scattering from Relaxor PMN-xPT

    Science.gov (United States)

    Krogstad, Matthew; Rosenkranz, Stephan; Osborn, Raymond; Wozniak, Justin; Ye, Feng; Ruff, Jacob; Gehring, Peter; Ye, Zuo-Guang; Phelan, Daniel

    Relaxor ferroelectrics possess intriguing electromechanical and dielectric properties, the microscopic physics of which is widely regarded to be related to local, correlated atomic displacements from long-range symmetry. However, despite numerous studies over the last few decades, the details of how short range correlations and disorder drive the relaxor behavior remain unresolved. Single crystal diffuse scattering provides a powerful probe of such deviations from an average structure correlated over varying length scales, and over the last few years, techniques and instruments for measuring diffuse scattering with both x-rays and neutrons have seen a dramatic improvement, allowing for large volumes of reciprocal space to be measured in little time. We present our recent complementary neutron and x-ray measurements on solid solutions of PMN-xPT which revealed new structure to the diffuse scattering of relaxors close to the morphotropic phase boundary.

  1. Isolation, In-111 labeling, and abscess detection efficiency of rabbit polymorphonuclear leukocytes (PMN) from blood and peritoneal fluid

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, K.M.; Elson, M.K.; Gerding, D.N.; Bamberger, D.M.; Forstrom, L.A.; Shafer, R.B.

    1984-01-01

    In-111 labeled blood and peritoneal exudate PMN were compared for labeling efficiency and ability to migrate to sites of experimental abscesses using both direct sampling and visual imaging techniques. Blood PMN were prepared by combining heparinized blood with 6% Hetastarch for 1 hour and layering the plasma over a double density Ficoll-Hy-paque gradient (S.G. 1.076 over 1.141). The PMN layer (90-99% PMN) at the interface yielded 10/sup 6/-10/sup 7/ PMN from 80-120 ml of blood. Peritoneal PMN were obtained by infusion of 0.1% glycogen, followed by infusion of saline after 4 or 18 hours. The exudate yielded 10/sup 7/-10/sup 8/ PMN (80-99% PMN). PMN suspensions were labeled for 30 minutes by addition of 100 ..mu..Ci of In-111-oxine, then washed twice. Percent cell-associated radioactivity of the labeled blood, 4 hour, and 18 hour peritoneal PMN was 89%, 88%, and 86%. The labeled PMN were injected intravenously into rabbits which had two of three abdominal capsules (table tennis balls drilled with 250 1.5 mm holes) inoculated with Staphylococcus aureus 4 hours earlier. Peak venous recovery of circulating labeled PMN, for blood, 4 hour and 18 hour peritoneal PMN was 60%, 43%, and 19%. Gamma camera images 24 hours after infusion into infected rabbits were superior with 4 hour peritoneal PMN. The peritoneal PMN harvested 4 hours after glycogen stimulation are simple to prepare, are obtainable in greater numbers than blood PMN, and result in better abscess visualization.

  2. Social learning of migratory performance

    Science.gov (United States)

    Mueller, Thomas; O'Hara, Robert B.; Converse, Sarah J.; Urbanek, Richard P.; Fagan, William F.

    2013-01-01

    Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were captive bred and artificially trained by ultralight aircraft on their first lifetime migration. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy.

  3. High-performance energy harvester fabricated with aerosol deposited PMN-PT material

    Science.gov (United States)

    Chen, C. T.; Lin, S. C.; Lin, T. K.; Wu, W. J.

    2016-11-01

    This paper reports a high-performance piezoelectric energy harvester (EH) fabricated with xPb(Mg1/3Nb2/3)-(l-x)PbTiO3 (PMN-PT) by aerosol deposition method. The result indicates that PMN-PT based EH owns 1.8 times output power which is higher than traditional PbZrxTi1- xO3 (PZT) based EH. In order to compare the output performance of EH fabricated with PMN- PT compared with PZT, the similar thickness of PMN-PT and PZT thin film is deposited on stainless steel subtracted. The experimental results show that PZT-based EH had a maximum output power of 4.65 μW with 1.11 Vp-p output voltage excited at 94.4 Hz under 0.5g base excitation, while the PMN-PT based device has a maximum output power of 8.42 μW with 1.49 Vp-p output voltage at a vibration frequency of 94.8 Hz and the same base excitation level. The volumetric power density was 82.95 μW/mm3 and 48.05 μW/mm3 for the device based on PMN- PT and PZT materials, respectively. All the results demonstrate that PMN-PT has better output performance than PZT.

  4. Strong magnetoelectric and spin phonon coupling in SmFeO3/PMN-PT composite

    Science.gov (United States)

    Ahlawat, Anju; Satapathy, S.; Sathe, V. G.; Choudhary, R. J.; Gupta, P. K.

    2016-08-01

    We have investigated spin phonon coupling in the strain coupled magnetoelectric SmFeO3/0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 (PMN-PT) composite in the temperature range of 300-650 K by Raman spectroscopy and magnetic measurements. The SmFeO3/PMN-PT composite shows sharp rise in magnetic moment across ferroelectric transition temperature (Tc) of PMN-PT. Around this transition temperature (Tc of PMN-PT), the temperature evolution of Raman spectra of the composite also shows anomalies in the phonon frequencies and line width corresponding to the SmFeO3 phase which indicate structural modifications in the SmFeO3 phase around Tc of PMN-PT. The observed structural, magnetic, and phonon anomalies of SmFeO3 around Tc of PMN-PT in SmFeO3/PMN-PT are attributed to spin-phonon coupling providing evidence of strong strain mediated magnetoelectric effects.

  5. Impairment of Neutrophil Migration to Remote Inflammatory Site during Lung Histoplasmosis

    Directory of Open Access Journals (Sweden)

    Alexandra I. Medeiros

    2015-01-01

    Full Text Available Histoplasma capsulatum (Hc induces a pulmonary disease in which leukotrienes promote activation and recruitment of effectors cells. It is also well-recognized that leukotriene B4 (LTB4 and platelet-activating factor (PAF induce leukocyte recruitment to inflammatory sites. We investigated the impact of pulmonary Hc infection on PMN migration to a remote inflammatory site. Our results show that pulmonary Hc infection impairs LTB4- or PAF-stimulated PMN recruitment to air pouch. Yet, remote inflammation did not modify PMN numbers in the bronchoalveolar lavage fluid (BALF of Hc-infected mice. Interestingly, the concomitant administration of PAF and LTB4 receptor antagonists inhibited PMN recruitment to both BALF and the remote site, demonstrating cooperation between both mediators. Along that line, our results show that PAF-elicited PMN chemotaxis was abrogated in 5-lipoxygenase-deficient animals. These results suggest caution in the indiscriminate use of anti-inflammatory drugs during infectious diseases.

  6. Energy scavenging based on a single-crystal PMN-PT nanobelt

    OpenAIRE

    Fan Wu; Wei Cai; Yao-Wen Yeh; Shiyou Xu; Nan Yao

    2016-01-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 − x)Pb(Mg1/3Nb2/3)O3 − xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from...

  7. Impedance and ferroelectric properties of Sr2+modified PZT-PMN ceramics

    Institute of Scientific and Technical Information of China (English)

    Arvind Kumar; SK Mishra

    2014-01-01

    Sr2+modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2+content in PZT-PMN.

  8. Nanodomain structures with hierarchical inhomogeneities in PMN-PT.

    Science.gov (United States)

    Kurushima, Kosuke; Kobayashi, Keisuke; Mori, Shigeo

    2012-09-01

    The nanometric domain configuration of (1 - x) Pb(Mg(1/3)Nb(2/3))O(3-x)PbTiO(3) [(1 - x)PMN-xPT] single crystals in the monoclinic phase around a morphotropic phase boundary (MPB) has been examined thoroughly by means of transmission electron microscopy (TEM). Domain structures with hierarchically inhomogeneous configuration were found in the monoclinic phase near the MPB region around x ~ 0.32, which are characterized as nanoscaled lamella-type domain structures with ~10 nm width inside macroscopic-sized banded domains with 100 to 200 nm width. To elucidate formation processes of the domain structures with hierarchically inhomogeneous configuration, an in situ TEM observation of changes of the domain structures in the temperature window between 298K and 500K was carried out. It is revealed that these nanoscaled lamella-type domain structures with ~10 nm width appear inside the banded domains as a result of the tetragonal structure and are inherent to the monoclinic phase.

  9. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Science.gov (United States)

    2010-01-25

    ... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife Service... Wildlife Service, are reopening the public comment period on our proposed rule to establish migratory...

  10. 75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

    Science.gov (United States)

    2010-05-28

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX09 Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... on October 27, 2003, to create regulations governing migratory bird rehabilitation in the...

  11. 76 FR 36508 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2011-06-22

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2011-12 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2011-12 hunting season. This supplement to the...

  12. 76 FR 54051 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2011-08-30

    ... Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  13. 77 FR 42919 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Science.gov (United States)

    2012-07-20

    ... July 20, 2012 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations; Notice of Meetings...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird...

  14. 78 FR 52657 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2013-08-23

    ... Bird Hunting; Final Frameworks for Early Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  15. Fine grains ceramics of PIN-PT, PIN-PMN-PT and PMN-PT systems: drift of the dielectric constant under high electric field.

    Science.gov (United States)

    Pham-Thi, M; Augier, C; Dammak, H; Gaucher, P

    2006-12-22

    Lead-based ferroelectric ceramics with (1-x)Pb(B1 B2)O3-xPbTiO3 formula have emerged as a group of promising materials for various applications like ultrasonic sonars or medical imaging transducers. (1-x)PMN-xPT, (1-x)PIN-xPT and ternary solutions xPIN-yPMN-zPT ceramics are synthesised using the solid state reaction method. Our objective is to achieve higher structural transition temperatures than those of PMN-PT ceramics with as good dielectric, piezoelectric and electromechanical properties. Ceramics capacitance and loss tangent are measured when the ac field of measurement increases up to E=500 V/mm. Behaviours of these materials under ac field are related to their coercive field and Curie temperature.

  16. Energy scavenging based on a single-crystal PMN-PT nanobelt

    Science.gov (United States)

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-03-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 ‑ x)Pb(Mg1/3Nb2/3)O3 ‑ xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs.

  17. Broadband ultrasonic linear array using ternary PIN-PMN-PT single crystal.

    Science.gov (United States)

    Wang, Wei; Zhao, Xiangyong; Or, Siu Wing; Leung, Chung Ming; Zhang, Yaoyao; Jiao, Jie; Luo, Haosu

    2012-09-01

    Ternary Pb(In(1/2)Nb(1/2))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) single crystal was investigated for potential application in ultrasonic linear array. Orientation and temperature dependences of height extensional electromechanical coupling coefficient k'(33) for PIN-PMN-PT single crystal were studied. It was found that the [001] poled PIN-PMN-PT diced along the [100] direction would achieve a maximum k'(33) (~87%) and the service temperature was up to 110 °C. Ultrasonic linear arrays using PIN-PMN-PT single crystal and PZT ceramic were fabricated and compared. The bandwidth at -6 dB, two-way insertion loss and pulse length of the PIN-PMN-PT array were 98.6%, -45.1 dB, and 0.28 μs, respectively, which were about 25% broader, 3.7dB higher, and 0.08 μs shorter than those of the PZT array. The experimental results agreed well with the theoretical simulation. These superior performances were attributable to the excellent piezoelectric properties of PIN-PMN-PT single crystal.

  18. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    Science.gov (United States)

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  19. Ten years of International Migratory Bird Day

    Science.gov (United States)

    Jennifer Wheeler; Susan Bonfield

    2005-01-01

    Public awareness and concern are crucial components of migratory bird conservation. Citizens who are enthusiastic about birds, informed about threats, and empowered to become involved in addressing those threats can make a tremendous contribution to maintaining healthy bird populations. One of the most successful vehicles for public education on migratory birds is...

  20. Mapping global diversity patterns for migratory birds.

    Directory of Open Access Journals (Sweden)

    Marius Somveille

    Full Text Available Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  1. Mapping global diversity patterns for migratory birds.

    Science.gov (United States)

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  2. Impaired bactericidal but not fungicidal activity of polymorphonuclear neutrophils in patients with chronic lymphocytic leukemia.

    Science.gov (United States)

    Kontoyiannis, Dimitrios P; Georgiadou, Sarah P; Wierda, William G; Wright, Susan; Albert, Nathaniel D; Ferrajoli, Alessandra; Keating, Michael; Lewis, Russell E

    2013-08-01

    We examined the qualitative polymorphonuclear neutrophil (PMN)-associated immune impairment in patients with chronic lymphocytic leukemia (CLL) by characterizing phagocytic killing of key non-opsonized bacterial (Staphylococcus aureus and Pseudomonas aeruginosa) and fungal (Candida albicans and Aspergillus fumigatus) pathogens. Neutrophils were collected from 47 non-neutropenic patients with CLL (PMN count > 1000/mm(3)) and age-matched and young healthy controls (five each). A subset of patients (13%) had prior or subsequent infections. We found that the patients with CLL had diminished PMN microbicidal response against bacteria but not against fungi compared with the controls. Compared to patients with effective PMN responses, we did not identify differences of basal PMN pathogen-associated molecular pattern receptor gene expression, soluble pathogen-associated molecular pattern gene expression or inflammatory cytokine signatures in patients with impaired PMN responses when PMNs were analyzed in multiplex real-time polymerase chain reaction assays. However, differences in PMN microbicidal response against A. fumigatus in patients with CLL were associated with the degree of hypogammaglobulinemia.

  3. PZN-PMN-PT铁电晶体的生长及表征%Growth and Properties of PZN-PMN-PT Ferroelectric Crystals

    Institute of Scientific and Technical Information of China (English)

    惠增哲; 田瑞英; 龙伟; 李晓娟; 方频阳

    2013-01-01

    本文采用高温溶液法制备了PZN-PMN-PT晶体,利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析了晶体的结构和微观形貌,通过偏光显微镜和介电温谱观测了晶体电畴和介电性能随温度的变化.研究结果表明,采用高温溶液法可以制备出纯钙钛矿相结构的PZN-PMN-PT晶体,晶体颗粒呈淡黄色多面体形态,最大尺寸为4 mm×2.5 mm×2 mm,电畴的消光角为45°,三方四方相变温度达113℃,居里温度高达246℃.PZN-PMN-PT晶体的三方四方相变温度和居里温度均高于PZN-PT和PMN-PT晶体.

  4. 低迟滞PMN-PT叠层型驱动器件的制备%Fabrication of Low Hysteresis PMN-PT Stack Actuator

    Institute of Scientific and Technical Information of China (English)

    李勤男; 祁阳

    2012-01-01

    研究了PMN-PT电致应变陶瓷材料的铌铁矿法制备及其电致应变性能,以及该陶瓷膜叠层型驱动器件的制备条件及性能.结果表明,0.94PMN-0.06PT陶瓷的应变迟滞最小;利用压延法可以提高叠层陶瓷膜的密度等特性;叠层型驱动器件的成型压力、预烧和烧结阶段的压力分别为200和0.01 MPa时,驱动器件的应变迟滞小于百分之一,并且驱动特性优异.%PMN-PT electrostrictive ceramics were prepared by columbite method, and their electrostrictive properties were investigated. The conditions for preparing the stack actuator by ceramic thick films and its properties were investigated. The results showed that the strain hysteresis of 0.94PMN-0.06PT is the lowest. The stack ceramic thick films prepared by the rolling process have high densities and good properties. When the forming pressure and the pressure during calcining and sintering are 200MPa and 0. 01MPa, respectively, for the fabrication of stack actuator, the strain hysteresis of 0.94PMN-0.06PT stack actuator is lower than 1% and the actuator has good working properties.

  5. Advantage analysis of PMN-PT material for free-flooded ring transducers

    Institute of Scientific and Technical Information of China (English)

    He Zheng-Yao; Ma Yuan-Liang

    2011-01-01

    The acoustic radiation characteristics of free-flooded ring transducers made of PZT4 and PMN-PT materials are calculated and compared.First,the theoretical formulae for free-flooded ring transducers are studied.The resonant frequencies of a transducer made of PZT4 and PMN-PT materials are calculated. Then,the transmitting voltage responses of the free-flooded ring transducers are calculated using the finite element method.Finally,the acoustic radiation characteristics of the free-flooded ring transducers are calculated using the boundary element method.The calculated results show that the resonant frequencies of the free-flooded ring transducer made of PMN-PT are greatly reduced compared with those made of PZT4 with the same size.The transmitting voltage response of the transducer made of PMN-PT is much higher than that of the transducer made of PZT4.The calculated 3-dB beamwidth of the acoustic radiated far-field directivity of the free-flooded ring transducer made of PZT4 at the resonant frequency 1900 Hz is 63.6° and that of the transducer made of PMN-PT at the resonant frequency 1000 Hz is 64.6°.The comparison results show that the free-flooded ring transducer made of PMN-PT material has many advantages over that made of PZT4.The PMN-PT is a promising material for improving the performance of free-flooded ring transducers.

  6. LPS responsiveness and neutrophil chemotaxis in vivo require PMN MMP-8 activity.

    Directory of Open Access Journals (Sweden)

    Angus M Tester

    Full Text Available We identify matrix metalloproteinase (MMP-8, the polymorphonuclear (PMN leukocyte collagenase, as a critical mediator initiating lipopolysaccharide (LPS-responsiveness in vivo. PMN infiltration towards LPS is abrogated in Mmp8-null mice. MMP-8 cleaves LPS-induced CXC chemokine (LIX at Ser(4-Val(5 and Lys(79-Arg(80. LIX bioactivity is increased upon N-terminal cleavage, enhancing intracellular calcium mobilization and chemotaxis upon binding its cognate receptor, CXCR2. As there is no difference in PMN chemotaxis in Mmp8-null mice compared with wild-type mice towards synthetic analogues of MMP-8-cleaved LIX, MMP-8 is not essential for extravasation or cell migration in collagenous matrices in vivo. However, with biochemical redundancy between MMPs 1, 2, 9, and 13, which also cleave LIX at position 4 approximately 5, it was surprising to observe such a markedly reduced PMN infiltration towards LPS and LIX in Mmp8-/- mice. This lack of physiological redundancy in vivo identifies MMP-8 as a key mediator in the regulation of innate immunity. Comparable results were found with CXCL8/IL-8 and CXCL5/ENA-78, the human orthologues of LIX. MMP-8 cleaves CXCL8 at Arg(5-Ser(6 and at Val(7-Leu(8 in CXCL5 to activate respective chemokines. Hence, rather than collagen, these PMN chemoattractants are important MMP-8 substrates in vivo; PMN-derived MMP-8 cleaves and activates LIX to execute an in cis PMN-controlled feed-forward mechanism to orchestrate the initial inflammatory response and promote LPS responsiveness in tissue.

  7. Seasonal influences on sleep and executive function in the migratory White-crowned Sparrow (Zonotrichia leucophrys gambelii

    Directory of Open Access Journals (Sweden)

    Hannan Ciaran T

    2010-07-01

    Full Text Available Abstract Background We have previously shown that the White-crowned Sparrow (WCS decreases sleep by 60% during a period of migratory restlessness relative to a non-migratory period when housed in a 12 h light: 12 h dark cycle. Despite this sleep reduction, accuracy of operant performance was not impaired, and in fact rates of responding were elevated during the migratory period, effects opposite to those routinely observed following enforced sleep deprivation. To determine whether the previously observed increases in operant responding were due to improved performance or to the effects of migration on activity level, here we assessed operant performance using a task in which optimal performance depends on the bird's ability to withhold a response for a fixed interval of time (differential-reinforcement-of-low-rate-behavior, or DRL; elevated response rates ultimately impair performance by decreasing access to food reward. To determine the influence of seasonal changes in day length on sleep and behavioral patterns, we recorded sleep and assessed operant performance across 4 distinct seasons (winter, spring, summer and fall under a changing photoperiod. Results Sleep amount changed in response to photoperiod in winter and summer, with longest sleep duration in the winter. Sleep duration in the spring and fall migratory periods were similar to what we previously reported, and were comparable to sleep duration observed in summer. The most striking difference in sleep during the migratory periods compared to non-migratory periods was the change from discrete day-night temporal organization to an almost complete temporal fragmentation of sleep. The birds' ability to perform on the DRL task was significantly impaired during both migratory periods, but optimal performance was sustained during the two non-migratory periods. Conclusions Birds showed dramatic changes in sleep duration across seasons, related to day length and migratory status. Migration

  8. 50 CFR 20.40 - Gift of migratory game birds.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  9. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey....

  10. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    Science.gov (United States)

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT.

  11. Flexible piezoelectric PMN-PT nanowire-based nanocomposite and device.

    Science.gov (United States)

    Xu, Shiyou; Yeh, Yao-wen; Poirier, Gerald; McAlpine, Michael C; Register, Richard A; Yao, Nan

    2013-06-12

    Piezoelectric nanocomposites represent a unique class of materials that synergize the advantageous features of polymers and piezoelectric nanostructures and have attracted extensive attention for the applications of energy harvesting and self-powered sensing recently. Currently, most of the piezoelectric nanocomposites were synthesized using piezoelectric nanostructures with relatively low piezoelectric constants, resulting in lower output currents and lower output voltages. Here, we report a synthesis of piezoelectric (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanowire-based nanocomposite with significantly improved performances for energy harvesting and self-powered sensing. With the high piezoelectric constant (d33) and the unique hierarchical structure of the PMN-PT nanowires, the PMN-PT nanowire-based nanocomposite demonstrated an output voltage up to 7.8 V and an output current up to 2.29 μA (current density of 4.58 μA/cm(2)); this output voltage is more than double that of other reported piezoelectric nanocomposites, and the output current is at least 6 times greater. The PMN-PT nanowire-based nanocomposite also showed a linear relationship of output voltage versus strain with a high sensitivity. The enhanced performance and the flexibility of the PMN-PT nanowire-based nanocomposite make it a promising building block for energy harvesting and self-powered sensing applications.

  12. Electric field modification of magnetotransport in Ni thin films on (011) PMN-PT piezosubstrates

    Science.gov (United States)

    Tkach, Alexander; Kehlberger, Andreas; Büttner, Felix; Jakob, Gerhard; Eisebitt, Stefan; Kläui, Mathias

    2015-02-01

    This study reports the magnetotransport and magnetic properties of 20 nm-thick polycrystalline Ni films deposited by magnetron sputtering on unpoled piezoelectric (011) [PbMg1/3Nb2/3O3]0.68-[PbTiO3]0.32 (PMN-PT) substrates. The longitudinal magnetoresistance (MR) of the Ni films on (011) PMN-PT, measured at room temperature in the magnetic field range of -0.3 T PMN-PT substrate, which results in a transfer of strain to the Ni film, the MR value decreases by factor of 20 for the current along [100] of PMN-PT and slightly increases for the [ 01 1 ¯ ] current direction. Simultaneously, a strong increase (decrease) in the field value, where the MR saturates, is observed for the [ 01 1 ¯ ] ([100]) current direction. The anisotropic magnetoresistance is also strongly affected by the remanent strain induced by the electric field pulses applied to the PMN-PT in the non-linear regime revealing a large (132 mT) magnetic anisotropy field. Applying a critical electric field of 2.4 kV/cm, the anisotropy field value changes back to the original value, opening a path to voltage-tuned magnetic field sensor or storage devices. This strain mediated voltage control of the MR and its dependence on the crystallographic direction is correlated with the results of magnetization reversal measurements.

  13. Technology and Properties PMN-PT-PS-PFN:LI Material for Multilayer Capacitor

    Directory of Open Access Journals (Sweden)

    Niemiec P.

    2013-12-01

    Full Text Available W pracy zaprojektowano i otrzymano wieloskładnikowy materiał o wzorze 0.6075PMN-0.2025PT-0.09PS-0.1PFN:Li (PMN-PT-PS-PFN:Li dla zastosowań na podłoża do wielowarstwowych kondensatorów MLCC. Otrzymywanie materiału PMN-PT-PS-PFN:Li było prowadzone dwiema metodami syntetyzowania. W pierwszej metodzie do otrzymania PMN-PT-PS- PFN:Li zastosowano syntetyzowanie prostych związków (tlenki, węglany, w drugiej metodzie zastosowano syntetyzowanie złożonych związków (MgNb2O6, i FeNbO4 oraz prostych związków (tlenków PbO. Ti O: i węglanu U2CO3. Z syntetyzowanego proszku materiału PMN-PT-PS-PFN:Li otrzymano ceramiczne próbki które zostały poddane kom- pleksowym badaniom. Przeprowadzono badania rentgenowskie, mikrostrukturalne oraz ferroelektrycznych, dielektrycznych i sprężystych właściwości.

  14. Problems confronting migratory birds in Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We describe in this paper problems affecting the well-being of Alaska's migratory birds in the belief that recognition of these problems is a step towards finding...

  15. High Frequency PMN-PT 1-3 Composite Transducer for Ultrasonic Imaging Application.

    Science.gov (United States)

    Sun, Ping; Wang, Gaofeng; Wu, Dawei; Zhu, Benpeng; Hu, Changhong; Liu, Changgeng; Djuth, Frank T; Zhou, Qifa; Shung, K Kirk

    2010-01-01

    Development of PMN-PT single crystal/epoxy 1-3 composites for high-frequency ultrasonic transducers application is presented. The composite was fabricated by using a DRIE dry etching process with a 45% volume fraction of PMN-PT. A 35 MHz ultrasound flat transducer was fabricated with the composite, which was found to have an effective electromechanical coupling coefficient of 0.81, an insertion loss of 18 db, and a -6 dB bandwidth as high as 100%. Tungsten wire phantom image shows that the transducer had an axial resolution of 30 μm, which was in good agreement with the theoretical expectation. The initial results showed that the PMN-PT/epoxy 1-3 composite has many attractive properties over conventional piezoelectric materials for medical imaging applications.

  16. Application of PMN-32PT Piezoelectric Crystals for Novel Air-coupled Ultrasonic Transducers

    Science.gov (United States)

    Kazys, Rymantas Jonas; Sliteris, Reimondas; Sestoke, Justina

    Due to very high piezoelectric properties of PMN-PT crystals they may significantly improve performance of air-coupled ultrasonic transducers. For these purpose vibrations of PMN-PT rectangular plates and strips were investigated. An air-coupled ultrasonic transducer and array consisting of 8 single piezoelectric strips were designed. Operation of the transducer was simulated by the finite element method using ANSYS Mechanical APDL Product Launcher software. Spatial distributions of displacements inside piezoelectric elements and matching strip were obtained. Experimental investigations were carried out by the laser Doppler vibrometer Polytec OFV-5000 and the Bruel&Kjaer microphone 4138 with the measurement amplifier NEXUS WH 3219. It was found that performance of the ultrasonic transducer with PMN-32PT crystals was a few times better than of a PZT based ultrasonic transducer.

  17. Electric-field-modulated nonvolatile resistance switching in VO₂/PMN-PT(111) heterostructures.

    Science.gov (United States)

    Zhi, Bowen; Gao, Guanyin; Xu, Haoran; Chen, Feng; Tan, Xuelian; Chen, Pingfan; Wang, Lingfei; Wu, Wenbin

    2014-04-09

    The electric-field-modulated resistance switching in VO2 thin films grown on piezoelectric (111)-0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 (PMN-PT) substrates has been investigated. Large relative change in resistance (10.7%) was observed in VO2/PMN-PT(111) hererostructures at room temperature. For a substrate with a given polarization direction, stable resistive states of VO2 films can be realized even when the applied electric fields are removed from the heterostructures. By sweeping electric fields across the heterostructure appropriately, multiple resistive states can be achieved. These stable resistive states result from the different stable remnant strain states of substrate, which is related to the rearrangements of ferroelectric domain structures in PMN-PT(111) substrate. The resistance switching tuned by electric field in our work may have potential applications for novel electronic devices.

  18. Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.

    Science.gov (United States)

    Xiao, Pingping; Wang, Xianping; Sun, Jingjing; Huang, Meizhen; Chen, Xianfeng; Cao, Zhuangqi

    2012-06-18

    A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established. With this correlation and the measurement of the effective RI change to the applied voltage, the quadratic EO and CPE coefficients of PMN-PT ceramics are obtained simultaneously. The obtained results are further checked by fitting the variations of effective RI to a quadratic function. Our measurement method can be extended to a wide range of other materials.

  19. Migratory diversity predicts population declines in birds.

    Science.gov (United States)

    Gilroy, James J; Gill, Jennifer A; Butchart, Stuart H M; Jones, Victoria R; Franco, Aldina M A

    2016-03-01

    Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

  20. Progress in the Growth,Properties and Application of PMN-PT Crystal%PMN-PT晶体的生长、性质和应用进展

    Institute of Scientific and Technical Information of China (English)

    戴振国; 董胜明; 尹振华; 李福奇; 翟仲军; 张健; 王继扬

    2005-01-01

    综述了驰豫型铁电单晶PMN-PT[(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3]的研究现状,介绍了这种晶体的结构、生长和性质,讨论了其研究进展和发展趋势,并对其的可能应用做了简要分析.

  1. Time Domain Dielectric Spectroscopy of PMN-PT Ferroelectric Single Crystal%PMN-PT铁电单晶的时域介电谱

    Institute of Scientific and Technical Information of China (English)

    刘俊刁; 沈韩; 陈敏

    2010-01-01

    测量了PMN-PT单晶0℃至120℃范围内的时域介电谱.分出了晶体中晶格极化,铁电畴运动和屏蔽电荷激发三种极化机构的作用.各极化机构的响应时间对样品的极化状态非常敏感.

  2. Cofiring behavior of NiCuZn ferrite/PMN ferroelectrics di-layer composites

    Institute of Scientific and Technical Information of China (English)

    MIAO Chun-lin; ZHOU Ji; YUE Zhen-xing; LI Long-tu

    2005-01-01

    The cofiring compatibility between ferrite and relaxor ferroelectrics materials is the key issue in the production of multilayer chip LC filters. The cofiring behavior, interfacial microstructure and diffusion of di-layer composites of NiCuZn ferrite/PMN relaxor ferroelectrics are studied. In order to analyze the matching condition of thermodynamic properties between ferrite and relaxor ferroelectric ceramics, TMA is performed on PMN ferroelectrics and NiCuZn ferrite with certain percentage of Bi2 O3, respectively. EDS results demonstrate that serious element diffusions exist at the interface, which is in accordance with the phase analysis based on XRD patterns.

  3. Pengaruh Level HBA1C Terhadap Fungsi Fagositosis Neutrofil (PMN pada Penderita Periodontitis Diabetika

    Directory of Open Access Journals (Sweden)

    Ahmad Syaify

    2016-08-01

    Full Text Available Latar belakang. Diabetes Melitus (DM merupakan penyakit sistemik yang sangat terkait dengan meningkatnya keparahan penyakit periodontal. Pada penderita DM diduga kuat bahwa keparahan periodontitis disebabkan oleh gangguan fungsi leukosit. Sel neutrofil (PMN diketahui berperan besar di dalam system pertahanan jaringan periodontal. Kontrol glikemik pada penderita DM dapat diketahui dengan pemeriksaan level HbA1c. Tujuan. Penelitian ini untuk mengetahui pengaruh level HbA1c pada penderita periodontitis diabetika terhadap fungsi fagositosis sel PMN. Bahan dan Cara. Sel PMN dari darah tepi 15 pasien periodontitis terdiri 5 periodontitis tana DM, 5 periodontitis diabetika terkontrol (HbA1c7 diuji aktivitas fagositosinya dengan partikel lateks. Fungsi fagositosis dihitung dengan rumus indeks fagositosis (IF. Hasil. Terdapat perbedaan significant IF sel PMN subyek periodontitis diabetika tidak terkontrol (HbA1c>7 dengan periodontitis non DM. IF tertinggi pada subyek periodontitis non DM dan tertinggi pada periodontitis diabetika tidak terkontrol (HbA1c>7. Kesimpulan. Level HbA1c berpengaruh terhadap fungsi fagositosis sel PMN yang dilihat dari indeks fagositosis (IF.    Background. Diabetes mellitus is a systemic condition that has long been associated with an increased and severity of periodontal disease. The severity of periodontitis in diabetic patients was thought caused by decreation of leukocytes function. Polymorphonuclear leukocytes (PMN play a key role in the maintenance of gingival (HbA1c level. Aims. The objective of this study was to analyse the influence of HbA1C level to fagositosis index on diabetic periodontitis patients. Material and Methods. PMN were taken from peripheral blood of 15 periodontitis patients consisted of 5 subject with uncontrolled DM (HbA1c>7, 5 subject with controlled DM (HbA1c7 and periodontitis non diabetic subjects. The higest PI was on diabetic periodontitis with HbA1c level >7 and the lowest PI was on non

  4. The nature of gamma ray blazar candidate PMN J1326-5256

    CERN Document Server

    Bignall, H; Jauncey, D; Senkbeil, C; Lovell, J; Ellingsen, S

    2007-01-01

    A comparison of AGN detected at gamma ray energies by EGRET with flat-spectrum radio sources observed in surveys for intraday variability reveals that a remarkably high fraction of EGRET blazars show significant interstellar scintillation at centimetre wavelengths. Scintillating AGN will therefore be targets of interest for GLAST, scheduled for launch in early 2008. We suggest that the variable, scintillating flat-spectrum radio source PMN J1326-5256 is associated with the unidentified EGRET source 3EG J1316-5244. We describe the properties of PMN J1326-5256 and present recent results of monitoring with the ATCA and Ceduna radio telescopes.

  5. Characterization of PMN-PT piezoelectric single crystal and PMN-PT 1-3 composite at elevated temperatures by electrical impedance resonance analysis.

    Science.gov (United States)

    Wu, Zhengbin; Xi, Kui

    2014-07-01

    In this paper, lead magnesium niobate-lead titanate (PMN-PT) piezoelectric single crystal and its 1-3 composite counterpart were characterized and analyzed under different stable temperatures using both a Simulated Annealing (SA) optimization algorithm and the commercial software PRAP (Piezoelectric Resonance Analysis Program). Electrical impedance resonance characteristics of the two material samples over the range 25-125 °C were measured. The correlation between experimental data and numerical fits derived from both SA and PRAP is considered. Calculation of the determination coefficient (R1(2)) between numerically fitted and measured results is above 95% for both methods. Furthermore, variations in the number of data values used for the fit introduced no more than 3.1% uncertainty on the calculated material parameters. It is found that the complex material parameters of PMN-PT composite are more dependent on temperature than the single crystal. The phase transition of the PMN-PT, which is close to 90 °C, has an effect on the high temperature material characteristics of both piezoelectric materials. These calculated complex material parameters can be used for the design of ultrasonic transducers for elevated temperature applications.

  6. ynthesis of Pure Perovskite Phase PMN - PT by Modified Columbite Precursor Method%纯钙钛矿相PMN-PT的改进铌铁矿法合成

    Institute of Scientific and Technical Information of China (English)

    曹林洪; 姚熹

    2007-01-01

    以碱式碳酸镁代替氧化镁,在1 100 ℃×6 h条件下合成出纯的铌铁矿相,从而避免了第二步预烧过程中焦绿石相的形成.以碱式碳酸铅代替氧化铅,在650-1 150 ℃不同温度下预烧2 h后的XRD相组成分析表明:预烧粉体主相为钙钛矿相的PMN-PT,随预烧温度提高,PMN-PT固溶体不断形成,同时PbO发生四方相-正交相转变,但均未出现焦绿石相.因此,该工艺特别适合在需要过量PbO来实现低温烧结制备PMN-PT陶瓷的情况.

  7. 78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-11-01

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for... control of depredating birds. A depredation order allows the take of specific species of migratory birds for specific purposes without need for a depredation permit. The depredation order at 50 CFR 21.44...

  8. 78 FR 52123 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Science.gov (United States)

    2013-08-22

    ... Species; 2006 Consolidated Highly Migratory Species Fishery Management Plan; Amendment 7 AGENCY: National... 7 to the 2006 Consolidated Highly Migratory Species (HMS) Fishery Management Plan (FMP) to control... quota categories utilize quota. In this notice, NMFS announces the dates and logistics for 10...

  9. Modeling the Geography of Migratory Pathways and Stopover Habitats for Neotropical Migratory Birds

    Directory of Open Access Journals (Sweden)

    Roger Tankersley, Jr.

    2003-07-01

    Full Text Available Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixed orientation and fixed nightly flight distance between stopovers during spring migration, we explore whether a simple endogenous migratory program is sufficient to ensure successful migration across the modern landscape. Our model runs suggest that the modern distribution of optimum stopovers in the eastern United States can be adequately exploited by birds following migratory pathways defined by fixed-orientation and fixed-distance nightly flights. Longer flight distances may increase the chances of success by enabling migrants to bypass locales offering little habitat. Our results also suggest that most southwest-northeast migratory pathways through the Appalachian mountains are intact. Lack of optimal habitat at key locations in the Southeast causes many modeled pathways to fail. We present a speculative view of regional migration patterns implied by predominant ideas found in stopover ecology literature, and demonstrate the need for broad-scale migration research, in the hope that our approach will foster other continental- and regional-scale projects.

  10. 78 FR 27927 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-05-13

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: We propose to revise the regulations that allow control of depredating birds in some counties...

  11. 78 FR 67183 - Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird...

    Science.gov (United States)

    2013-11-08

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for... Bird Treaty Act (16 U.S.C. 703-711) and the Fish and Wildlife Act of 1956 (16 U.S.C. 742d)...

  12. Research of the magnetoelectric effect of PMN -PT/CFO in magnetic field%磁场作用下PMN-PT/CFO的磁电效应研究

    Institute of Scientific and Technical Information of China (English)

    郭红力; 杨焕银; 陶冶

    2014-01-01

    In terms of elasticity mechanical theory model ,the magnetoelectric voltage coefficient formula is estab-lished ,using the magnetostrictive properties of CoFe2 O4 (CFO) in the magnetic field ,we obtain the changing re-lations of Pb(Mg1/3 Nb2/3 ) O3 -PbTiO3 (PMN-PT )/CFO magnetoelectric voltage coefficient changing with the magnetic field and other parameters .The magnetoelectric voltage coefficient is also studied as the function of the Magnetic field intensity 、PMN-PT volume fraction v、interface coupling coefficient k and PMN -PT dielectric constant in magnetic field .The results show that the magnetoelectric voltage coefficient increase firstly ,then gradually decreases to zero with the increase of PMN -PT volume fraction and magnetic intensity ;the magneto-electric voltage coefficient strongly depends on the interface coupling coefficient ,which will largely reduce mag-netoelectric effect ;Meanwhile ,Magnetoelectric effect has a certain frequency characteristic ,with the increase of frequency ,which increase gradually and reaches stability .%在弹性力学模型下,推导非理想耦合状态的磁电(ME)电压系数公式。利用CoFe2 O4(CFO)随磁场变化的磁致伸缩特性,得到Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN -PT)与CFO复合材料的磁电电压系数随磁场以及各参量的变化关系公式。研究了磁电电压系数在磁场下随磁场强度、压电相体积分数 v、界面耦合系数 k以及PM N-PT介电常数之间的变化关系。研究结果发现:磁电电压系数随PM N-PT体积分数和磁场强度的增大,表现为先增大,后逐渐减小至零;磁电电压系数强烈地依赖于界面耦合系数,耦合系数减小会极大降低复合材料的磁电效应;同时,磁电效应具有一定的频率特性,随着频率的逐渐增大而增大,直至达到稳定。

  13. NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

    DEFF Research Database (Denmark)

    Ajello, M.; Ghisellini, G.; Paliya, V. S.;

    2016-01-01

    Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power...

  14. Recent Developments on High Curie Temperature PIN-PMN-PT Ferroelectric Crystals.

    Science.gov (United States)

    Zhang, Shujun; Li, Fei; Sherlock, Nevin P; Luo, Jun; Lee, Hyeong Jae; Xia, Ru; Meyer, Richard J; Hackenberger, Wesley; Shrout, Thomas R

    2011-03-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) ferroelectric crystals attracted extensive attentions in last couple years, due to their higher usage temperatures range (> 30°C) and coercive fields (~5kV/cm), meanwhile maintaining similar electromechanical couplings (k(33)> 90%) and piezoelectric coefficients (d(33)~1500pC/N), when compared to their binary counterpart Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3). In this article, we reviewed recent developments on the PIN-PMN-PT single crystals, including the Bridgman crystal growth, dielectric, electromechanical, piezoelectric and ferroelectric behaviors as function of temperature and dc bias. Mechanical quality factor Q was studied as function of orientation and phase. Of particular interest is the dynamic strain, which related to the Q and d(33), was found to be improved when compared to binary system, exhibiting the potential usage of PIN-PMN-PT in high power application. Furthermore, PIN-PMN-PT crystals exhibit improved thickness dependent properties, due to their small domain size, being on the order of 1μm. Finally, the manganese acceptor dopant in the ternary crystals was investigated and discussed briefly in this paper.

  15. Single crystal PMN-PT/epoxy 1-3 composite for energy-harvesting application.

    Science.gov (United States)

    Ren, Kailiang; Liu, Yiming; Geng, Xuecang; Hofmann, Heath F; Zhang, Qiming M

    2006-03-01

    One key parameter in using electroactive materials to harvest electric energy from mechanical sources is the energy conversion efficiency. Recently, it was shown that, in the relaxor ferroelectric PMN-PT single crystals, a very high longitudinal electromechanical coupling factor (>90%) can be obtained. This paper investigates energy harvesting using 1-3 composites of PMN-PT single crystals in a soft epoxy matrix. It is shown that 1-3 composites enable the single crystals operating in the longitudinal mode to achieve high efficiency for energy harvesting, and the soft-polymer, matrix-supported single-crystal rods maintain high mechanical integrity under different external loads. For comparison, 1-3 composites with piezoceramic PZT also are investigated in energy-harvesting applications, and the results show that the high coupling factor of single crystal PMN-PT 1-3 composites leads to much higher electric energy output for similar mechanical energy input. The harvested energy density of 1-3 composite with single crystal (22.1 mW/cm3 under a stress of 40.4 MPa) is about twice of that harvested with PZT ceramic 1-3 composite (12 mW/cm3 under a stress of 39 MPa). At a higher stress level, the harvested-energy density of 1-3 PMN-PT single crystal composite can reach 96 mW/cm3.

  16. PMN-PT-PZT composite films for high frequency ultrasonic transducer applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2012-06-01

    We have successfully fabricated x(0.65PMN-0.35PT)-(1 - x)PZT (xPMN-PT-(1 - x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol-gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT-(1 - x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT-0.1PZT thick film transducer is built. It has 200 MHz center frequency with a -6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB.

  17. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

    The function of migratory bird calls: do they influence orientation and navigation?   Thomas Reichl1, Bent Bach Andersen2, Ole Naesbye Larsen2, Henrik Mouritsen1   1Institute of Biology, University of Oldenburg, Oldenburg, D-26111 Oldenburg, Germany 2Institute of Biology, University of Southern...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...... the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...

  18. PMN-PT驰豫铁电单晶及其超声换能器性能研究%PMN-PT Ferroelectric Relaxor Crystal and Its Ultrasonic Transducer

    Institute of Scientific and Technical Information of China (English)

    李国荣; 罗豪; 殷庆瑞

    2001-01-01

    测试了PMN-PT(67/33)切型铁电单晶的机电性能,分析了该晶体与常用压电材料在微观结构和机电性能上差异.对该压电单晶未调制下纵向长度伸缩振动模超声换能器性能进行了理论分析.讨论了压电单晶的机械和介电损耗对超声换能器性能的规律.

  19. Modeling and analyzing the dielectric spectrum of PMN-xPT ceramics%PMN-xPT陶瓷的介电温谱拟合与分析

    Institute of Scientific and Technical Information of China (English)

    闫宗林; 姚熹; 张良莹; 严辉

    2004-01-01

    用双机制模型分析、拟合了不同PT组份弛豫型铁电陶瓷PMN-xPT的介电行为.研究表明随着PT组份的增加,极化机制发生明显的变化.通过分析极化机制随频率变化的情况,解释了Tm与ω的V-F关系的拟合参数随频率区间改变的现象.

  20. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface.

    Science.gov (United States)

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M; Brown, Gail J; Sun, Nian X

    2014-01-14

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling.

  1. 76 FR 9529 - Migratory Birds; Draft Eagle Conservation Plan Guidance

    Science.gov (United States)

    2011-02-18

    ... Fish and Wildlife Service 50 CFR Part 22 RIN 1018-AX53 Migratory Birds; Draft Eagle Conservation Plan...; Division of Migratory Bird Management; U.S. Fish and Wildlife Service; 4401 North Fairfax Drive, Mail Stop... Protection Act (BGEPA), the Migratory Bird Treaty Act, and the Endangered Species Act. BGEPA prohibits...

  2. 78 FR 3446 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Science.gov (United States)

    2013-01-16

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2013-14 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior,...

  3. 78 FR 78377 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Science.gov (United States)

    2013-12-26

    ... Fish and Wildlife Service RIN 1018-AZ80 Migratory Bird Hunting; Service Regulations Committee Meeting... preliminary issues concerning the 2014-15 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior,...

  4. 77 FR 1718 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Science.gov (United States)

    2012-01-11

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2012-13 migratory bird hunting regulations. DATES: The meeting will be held... CONTACT: Chief, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of...

  5. 77 FR 60381 - Migratory Bird Conservation; Executive Order 13186

    Science.gov (United States)

    2012-10-03

    ... National Oceanic and Atmospheric Administration RIN 0648-XC148 Migratory Bird Conservation; Executive Order... the U.S. Fish and ] Wildlife Service (FWS) to promote the conservation of migratory birds. DATES: This... Migratory Birds''. One of the requirements of E.O. 13186 is that each Federal agency taking actions...

  6. 50 CFR 92.22 - Subsistence migratory bird species.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  7. 弛豫铁电体材料PMN及PMN-PT的电子显微学研究%Electron microscopy investigation on relaxor-ferroelectrics PMN and PMN-PT

    Institute of Scientific and Technical Information of China (English)

    王慧; 朱静; 苗澍; 金红政; 张孝文

    2007-01-01

    弛豫铁电体PMN(Pb(Mg1/3Nb2/3)O3)和PMN-xPT(Pb(Mg1/3Nb2/3)O3-xPbTiO3)由纳米畴结构组成.在弛豫铁电体PMN中B位有序的模型,以及有序畴和极化微区的关系是长期悬而未决的科学问题.本文采用纳米束电子衍射和能谱分析结合的手段确定了B位有序的杂乱位置模型;在有序畴和无序基体之间的成分波动最剧烈,有序无序界面可能是极化中心的位王;电子衍射和高分辨像还发现了片状反铁电畴结构,这种结构与铁电有序相互竞争,使得PMN中局部结构的相互竞争更加复杂.在PMN-xPT中准同型相界附近的单斜相的本质一直存在异议,X光衍射、中子衍射以及偏光显微镜只能给出宏观的结果,不能给出纳米尺度的结构信息,本文利用会聚束电子衍射,成功的解决了这一问题,确定单斜相Mc具有多层次的畴结构,在纳米尺度具有四方对称性,而在宏观尺度由于平均效应具有单斜对称性.文中还讨论了采用电子显微学方法研究铁电体时,遇到的技术难点及相应的解决方法.

  8. 75 FR 27143 - Migratory Bird Hunting; Proposed 2010-11 Migratory Game Bird Hunting Regulations (Preliminary...

    Science.gov (United States)

    2010-05-13

    ... the Protection of Migratory Birds and Game Mammals provide for the legal subsistence harvest of... Federal Drive, Fort Snelling, MN 55111-4056; (612) 713-5432. Region 4 (Alabama, Arkansas, Florida,...

  9. 76 FR 19875 - Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary...

    Science.gov (United States)

    2011-04-08

    ... Convention and the subsequent 1936 Mexico Convention for the Protection of Migratory Birds and Game Mammals... Building, One Federal Drive, Fort Snelling, MN 55111-4056; (612) 713- 5432. Region 4 (Alabama,...

  10. 78 FR 21199 - Migratory Bird Hunting; Proposed 2013-14 Migratory Game Bird Hunting Regulations (Preliminary...

    Science.gov (United States)

    2013-04-09

    ... subsequent 1936 Mexico Convention for the Protection of Migratory Birds and Game Mammals provide for the... Drive, Fort Snelling, MN 55111-4056; (612) 713-5432. Region 4 (Alabama, Arkansas, Florida,...

  11. MIGRATORY AGRICULTURAL WORKERS IN THE UNITED STATES.

    Science.gov (United States)

    JORGENSON, JANET M.; AND OTHERS

    FIELD STUDIES WERE CONDUCTED IN 1960 IN THE LOWER RIO GRANDE VALLEY OF TEXAS AND IN IOWA TO AUGMENT INFORMATION ON MIGRATORY WORKERS. FACULTY-STUDENT TEAM FIELD TRIPS FOUND MANY FACTORS TO CONSIDER IN PROVIDING A CONSTRUCTIVE APPROACH TO THE PROBLEMS OF THE MIGRANT WORKER. CHILDREN OF THE MIGRANTS ARE NOT GETTING THE EDUCATION THEY NEED TO BREAK…

  12. MIGRATORY WORKERS IN THE UNITED STATES.

    Science.gov (United States)

    1965

    THE NEED FOR LARGE NUMBERS OF FARM WORKERS FOR SHORT PERIODS DURING THE CULTIVATION AND HARVESTING OF CROPS IN WIDELY SEPARATED AREAS RESULTS IN A MIGRATORY WORK FORCE OF APPROXIMATELY 400,000 PERSONS EACH YEAR. MIGRANTS ARE EMPLOYED TO AVOID LOSSES OF PERISHABLE CROPS IN THE FIELDS, TO TAKE ADVANTAGE OF GOOD WEATHER OR TO FORESTALL LOSSES DUE TO…

  13. 77 FR 58627 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Science.gov (United States)

    2012-09-21

    ... Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds; Final Rule...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds AGENCY: Fish and...

  14. 78 FR 58204 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Science.gov (United States)

    2013-09-23

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... selection. Taking of migratory birds is prohibited unless specifically provided for by annual...

  15. 75 FR 58993 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Science.gov (United States)

    2010-09-24

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds; Final Rule #0;#0;Federal Register / Vol. 75 , No. 185... Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Late Seasons and Bag and Possession...

  16. 78 FR 53199 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Science.gov (United States)

    2013-08-28

    ... Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the... Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska...; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; youth waterfowl day; and...

  17. 75 FR 53226 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Science.gov (United States)

    2010-08-31

    ... and Possession Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska, Hawaii...; woodcock; common snipe; sandhill cranes; sea ducks; early (September) waterfowl seasons; migratory game... seasons, limits, and other regulations for hunting migratory game birds under Sec. Sec. 20.101 through...

  18. 77 FR 53751 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Science.gov (United States)

    2012-08-31

    ... Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the... Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous United States, Alaska...; migratory game birds in Alaska, Hawaii, Puerto Rico, and the Virgin Islands; youth waterfowl day; and...

  19. 76 FR 54657 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Science.gov (United States)

    2011-09-01

    ... September 1, 2011 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game Birds in the Contiguous... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Early Seasons...

  20. 氟化物助烧PMN-PT陶瓷的制备与性能%Preparation and Properties on PMN-PT Ceramics with Fluoride Sintering Aids

    Institute of Scientific and Technical Information of China (English)

    曹林洪; 姚熹; 徐卓; 毛懿伟; 陈峻江; 贾玉蓉

    2007-01-01

    以铌铁矿预产物合成法制备氟化物(LiF、MgF2、CaF2)助烧0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3弛豫铁电陶瓷.采用XRD和SEM分析陶瓷相组成和显微结构,并对介电和压电性能进行测试.结果表明,所有陶瓷样品均为纯钙钛矿相,没有检测到其它杂相; LiF和MgF2助烧PMN-PT陶瓷的晶粒较大(约3~4 μm),而纯PMNT陶瓷和CaF2助烧PMN-PT陶瓷的晶粒较小(约0.5~1 μm);LiF和MgF2的添加使陶瓷峰值介电常数增大,压电性能提高,相变弥散程度减小,而添加CaF2使其峰值介电常数减小,压电性能下降,相变弥散程度增大.

  1. Pb(Mg1/3Nb2/3O3–PbTiO3 (PMN-PT Material for Actuator Applications

    Directory of Open Access Journals (Sweden)

    Hana Uršič

    2011-01-01

    Full Text Available Due to its large piezoelectric and electrostrictive responses to an applied electric field the (1−xPb(Mg1/3Nb2/3O3–xPbTiO3 (PMN-PT solid solution has been widely investigated as a promising material for different actuator applications. This paper discusses some of the recent achievements in the field of PMN-PT piezoelectric and electrostrictive actuators manufactured from PMN-PT single crystals, bulk ceramics, or thick films. The functional properties of PMN-PT materials and some representative examples of the investigated PMN-PT actuator structures and their applications are reported.

  2. 脉冲激光沉积PMN-PT薄膜及其性能研究%Characterization of PMN-PT Thin Film Formed by Femtosecond Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    童杏林; 姜德生; 刘恋; 刘忠明

    2008-01-01

    以较低温度烧结获得的PMN-PT块材料为靶,采用脉冲激光沉积方法在石英衬底上制备了PMN-PT薄膜,研究了后续退火处理对PMN-PT薄膜的结构及光学特性的影响.结果显示,采用脉冲激光沉积可获得质量较好的钙钛矿结构的PMN-PT薄膜,优化的后续退火温度大约在550℃~750℃之间.

  3. Spectral Variation of NLS1 Galaxy PMN J0948+0022

    Indian Academy of Sciences (India)

    X. N. Sun; Jin Zhang; Y. Lu; E. W. Liang; S. N. Zhang

    2014-09-01

    Four well-sampled Spectral Energy Distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity (c) and peak frequency (c) of its inverse Compton (IC) bump is found in both the observer and co-moving frames, indicating that the variations of luminosity are accompanied by the spectral shift. A correlation between cs and is found, and thus the magnification of external photon field by the bulk motion of the radiation regions is an essential reason for the spectral variation since, IC bump of PMN J0948+0022 is dominated by the EC process.

  4. Microstructure and Electromechanical Properties in PMnN-PZT Ceramics Sintered at Different Temperatures

    Institute of Scientific and Technical Information of China (English)

    Baoshan LI; Zhigang ZHU; Guorong LI; Aili DING

    2005-01-01

    The microstructure and piezoelectric properties of Pb[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 (PMnN-PZT) ceramics have been investigated at different sintering temperatures from 1070℃ to 1280℃. The experimental results suggest that grain sizes and electromechanical properties of the ceramics show strong sintering temperature dependences.Double polarization to electric field (P-E) loops of the PMnN-PZT ceramics are assumed to be the result of the pinning effect of the defect dipoles. The results obtained through X-ray photoelectron spectrum suggest that sintering temperature affects valence of the Mn ion and quantity of oxygen vacancies. Hence, a proper explanation is proposed to illustrate the fluctuation of mechanical quality factor (Qm) due to the sintering temperature.

  5. Lift-off PMN-PT Thick Film for High Frequency Ultrasonic Biomicroscopy.

    Science.gov (United States)

    Zhu, Benpeng; Han, Jiangxue; Shi, Jing; Shung, K Krik; Wei, Q; Huang, Yuhong; Kosec, M; Zhou, Qifa

    2010-10-01

    Piezoelectric 0.65Pb(Mg(1/3)Nb(2/3))O(3)-0.35PbTiO(3) (PMN-35PT) thick film with a thickness of approximately 12 µm has been deposited on the platinum buffered Si substrate via a sol-gel composite method. The separation of the film from the substrate was achieved using a wet chemical method. The lifted-off PMN-35PT thick film exhibited good dielectric and ferroelectric properties. At 1 kHz, the dielectric constant and the dielectric loss were 3,326 and 0.037, respectively, while the remnant polarization was 30.0 µC/cm(2). A high frequency single element acoustic transducer fabricated with this film showed a bandwidth at -6 dB of 63.6% at 110 MHz.

  6. Electric-field tunable spin diode FMR in patterned PMN-PT/NiFe structures

    Science.gov (United States)

    Zietek, Slawomir; Ogrodnik, Piotr; Skowroński, Witold; Stobiecki, Feliks; van Dijken, Sebastiaan; Barnaś, Józef; Stobiecki, Tomasz

    2016-08-01

    Dynamic properties of NiFe thin films on PMN-PT piezoelectric substrate are investigated using the spin-diode method. Ferromagnetic resonance (FMR) spectra of microstrips with varying width are measured as a function of magnetic field and frequency. The FMR frequency is shown to depend on the electric field applied across the substrate, which induces strain in the NiFe layer. Electric field tunability of up to 100 MHz per 1 kV/cm is achieved. An analytical model based on total energy minimization and the Landau-Lifshitz-Gilbert equation, taking into account the magnetostriction effect, is used to explain the measured dynamics. Based on this model, conditions for optimal electric-field tunable spin diode FMR in patterned NiFe/PMN-PT structures are derived.

  7. Switching of 800 nm femtosecond laser pulses using a compact PMN-PT modulator.

    Science.gov (United States)

    Adany, Peter; Price, E Shane; Johnson, Carey K; Zhang, Run; Hui, Rongqing

    2009-03-01

    A voltage-controlled birefringent cell based on ceramic PMN-PT material is used to enable fast intensity modulation of femtosecond laser pulses in the 800 nm wavelength window. The birefringent cell based on a PMN-PT compound has comparatively high electro-optic response, allowing for a short interaction length of 3 mm and thus very small size, low attenuation of 0.16 dB, and negligible broadening for 100 fs optical pulses. As an application example, agile wavelength tuning of optical pulses is demonstrated using the soliton self-frequency shift in a photonic crystal fiber. By dynamically controlling the optical power into the fiber, this system switches the wavelength of 100 fs pulses from 900 nm to beyond 1120 nm with less than 5 micros time. In addition, a feedback system stabilizes the wavelength drift against external conditions resulting in high wavelength stability.

  8. Spectral Variation of NLS1 Galaxy PMN J0948+0022

    CERN Document Server

    Sun, X N; Lu, Y; Liang, E W; Zhang, S N

    2013-01-01

    Four well-sampled spectral energy distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity L_c and peak frequency nu_c of its inverse Compton (IC) bump is found in both the observer and co-moving frames, indicating that the variations of luminosity are accompanied with the spectral shift. A correlation between L_c and delta is found, and thus the magnification of the external photon field by the bulk motion of the radiation regions is an essential reason for the spectral variation since the IC bump of PMN J0948+0022 is dominated by the EC process.

  9. NUSTAR, SWIFT, and GROND Observations of the Flaring MEV Blazar PMN J0641-0320

    DEFF Research Database (Denmark)

    Ajello, M.; Ghisellini, G.; Paliya, V. S.

    2016-01-01

    Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641-0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power......-law photon index of similar to 1 up to similar to 80 keV) indicates that the emission is produced via inverse Compton scattering off of photons coming from outside the jet. The overall spectral energy distribution of PMN J0641-0320 is typical of powerful blazars and, using a simple one-zone leptonic emission...... model, we infer that the emission region is located either inside the broad line region or within the dusty torus....

  10. North American migratory bird management issues

    Science.gov (United States)

    Wilson, M.H.; Ryan, D.A.

    1995-01-01

    As human population and industry have grown in North America, land-use practices have greatly altered the landscape. As a result of this changed landscape, several migratory bird populations have declined in recent years. For waterbirds, there have been several milestones: the 1986 North American Waterfowl Management Plan (NAWMP) and the 1989 North American Wetlands Conservation Act. As a result, the United States and Canada have established 12 habitat and 2 species joint ventures. The primary emphasis of waterfowl management in Canada-U.S. has been land purchase and lease, wetland restoration, and coordination of harvest rates. Because of its different biological and cultural context, Mexico has established other conservation priorities. Mexico has had a long-standing concern to conserve its biodiversity and, in addition, conservation of Mexican resources goes hand in hand with human community development. Unlike Canada-U.S., wetland conservation projects in'Mexico include information gathering, environmental education, and management planning for its 32 priority wetlands. For migratory landbirds' scientists attribute declines in several migrant populations to forest fragmentation on the breeding grounds, deforestation on the wintering grounds, pesticide poisoning, or the cumulative effects of habitat changes. In 1990, the Neotropical Migratory Bird Conservation Program, commonly known as Partners in Flight-Aves de las Americas-was initiated. The next step that is being proposed is the formation of a habitat conservation plan for landbirds modeled after the NAWMP. Management of migratory birds requires a strong international approach in order to coordinate actions for the benefit of migratory birds, their habitats, and the uses they provide.

  11. Magnetic field-induced ferroelectric domain structure evolution and magnetoelectric coupling for [110]-oriented PMN-PT/Terfenol-D multiferroic composites

    Science.gov (United States)

    Fang, F.; Jing, W. Q.

    2016-01-01

    Magnetic field-induced polarization rotation and magnetoelectric coupling effects are studied for [110]-oriented (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3/Tb0.3Dy0.7Fe2(PMN-xPT/Terfenol-D) multiferroic composites. Two compositions of the [110]-oriented relaxor ferroelectric single crystals, PMN-28PT and PMN-33PT, are used. In [110]-oriented PMN-28PT, domains of rhombohedral (R) and monoclinic (MB) phases coexist prior to the magnetic loadings. Upon the applied magnetic loadings, phase transition from monoclinic MB to R phase occurs. In [110]-oriented PMN-33PT, domains are initially of mixed orthorhombic (O) and MB phases, and the phase transition from O to MB phase takes place upon the external magnetic loading. Compared to PMN-28PT, the PMN-33PT single crystal exhibits much finer domain boundary structure prior to the magnetic loadings. Upon the magnetic loadings, more domain variants are induced via the phase transition in PMN-33PT than that in PMN-28PT single crystal. The finer domain band structure and more domain variants contribute to stronger piezoelectric activity. As a result, the composite of PMN-33PT/Terfenol-D manifests a stronger ME coupling than PMN-28PT/Terfenol-D composite.

  12. Magnetic field-induced ferroelectric domain structure evolution and magnetoelectric coupling for [110]-oriented PMN-PT/Terfenol-D multiferroic composites

    Directory of Open Access Journals (Sweden)

    F. Fang

    2016-01-01

    Full Text Available Magnetic field-induced polarization rotation and magnetoelectric coupling effects are studied for [110]-oriented (1-xPb(Mg1/3Nb2/3O3-xPbTiO3/Tb0.3Dy0.7Fe2(PMN-xPT/Terfenol-D multiferroic composites. Two compositions of the [110]-oriented relaxor ferroelectric single crystals, PMN-28PT and PMN-33PT, are used. In [110]-oriented PMN-28PT, domains of rhombohedral (R and monoclinic (MB phases coexist prior to the magnetic loadings. Upon the applied magnetic loadings, phase transition from monoclinic MB to R phase occurs. In [110]-oriented PMN-33PT, domains are initially of mixed orthorhombic (O and MB phases, and the phase transition from O to MB phase takes place upon the external magnetic loading. Compared to PMN-28PT, the PMN-33PT single crystal exhibits much finer domain boundary structure prior to the magnetic loadings. Upon the magnetic loadings, more domain variants are induced via the phase transition in PMN-33PT than that in PMN-28PT single crystal. The finer domain band structure and more domain variants contribute to stronger piezoelectric activity. As a result, the composite of PMN-33PT/Terfenol-D manifests a stronger ME coupling than PMN-28PT/Terfenol-D composite.

  13. Pengaruh Level HBA1C Terhadap Fungsi Fagositosis Neutrofil (PMN) pada Penderita Periodontitis Diabetika

    OpenAIRE

    Ahmad Syaify

    2016-01-01

    Latar belakang. Diabetes Melitus (DM) merupakan penyakit sistemik yang sangat terkait dengan meningkatnya keparahan penyakit periodontal. Pada penderita DM diduga kuat bahwa keparahan periodontitis disebabkan oleh gangguan fungsi leukosit. Sel neutrofil (PMN) diketahui berperan besar di dalam system pertahanan jaringan periodontal. Kontrol glikemik pada penderita DM dapat diketahui dengan pemeriksaan level HbA1c. Tujuan. Penelitian ini untuk mengetahui pengaruh level HbA1c pada penderita peri...

  14. Self-powered cardiac pacemaker enabled by flexible single crystalline PMN-PT piezoelectric energy harvester.

    Science.gov (United States)

    Hwang, Geon-Tae; Park, Hyewon; Lee, Jeong-Ho; Oh, SeKwon; Park, Kwi-Il; Byun, Myunghwan; Park, Hyelim; Ahn, Gun; Jeong, Chang Kyu; No, Kwangsoo; Kwon, HyukSang; Lee, Sang-Goo; Joung, Boyoung; Lee, Keon Jae

    2014-07-23

    A flexible single-crystalline PMN-PT piezoelectric energy harvester is demonstrated to achieve a self-powered artificial cardiac pacemaker. The energy-harvesting device generates a short-circuit current of 0.223 mA and an open-circuit voltage of 8.2 V, which are enough not only to meet the standard for charging commercial batteries but also for stimulating the heart without an external power source.

  15. High-power characterization of a microcutter actuated by PMN-PT piezocrystals.

    Science.gov (United States)

    Kuang, Yang; Sadiq, Muhammad; Cochran, Sandy; Huang, Zhihong

    2015-11-01

    An ultrasonic microcutter is an alternative approach to conventional ultrasonic instruments actuated by sandwich piezoelectric transducers for surgery. This paper reports high-power behavior of a microcutter actuated by the piezocrystal lead magnesium niobate-lead titanate (PMN-PT), defining its practical performance and the feasibility of PMNPT actuation for surgical applications. The microcutter was driven at resonance with constant current amplitudes, either unloaded or loaded by poultry breast tissue, until its behavior achieved a steady state. During this driving process, its electric impedance, resonant frequency, and vibration velocity, along with the temperature increase of the PMN-PT, were recorded in real time. The microcutter produced a maximum vibration velocity >2.8 m/s with an excitation current of 0.11 A(rms). The mechanical loss increased significantly with current amplitude, resulting in a maximum temperature increase approaching 50°C around the interface between the PMN-PT and the blade, where they were bonded together with epoxy. Because of the low phase-transition temperature of PMN-PT, this temperature rise prevented the microcutter from working at higher current amplitudes. Along with the high vibration velocity, it also caused a frequency shift downward by 3 kHz at the same current amplitude. During tests with poultry breast tissue, radiation reactance increased the resonant frequency and the radiation resistance increased the loss of the microcutter. However, the loss did not further increase the temperature of the piezoelectric material. The maximum force and the overall work required to penetrate the microcutter into poultry breast tissue were reduced by 47.1 ± 8% and 53.5 ± 6%, respectively, when the microcutter was actuated at a current of 0.07 A(rms).

  16. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Geetika; Umarji, A. M. [Materials Research Centre, Indian Institute of Science, Bangalore-560 012 (India); Maglione, Mario [ICMCB, Universite de Bordeaux,-CNRS, 87, Av Dr Schweitzer 33806 Pessac (France)

    2012-12-15

    Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  17. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Directory of Open Access Journals (Sweden)

    Geetika Srivastava

    2012-12-01

    Full Text Available Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  18. Structure and Physical Properties of PZT-PMnN-PSN Ceramics Near the Morphological Phase Boundary

    Directory of Open Access Journals (Sweden)

    Nguyen Dinh Tung Luan

    2014-01-01

    Full Text Available The 0.9Pb(ZrxTi1−xO3-0.07Pb(Mn1/3Nb2/3O3-0.03Pb(Sb1/2Nb1/2O3 (PZT-PMnN-PSN ceramics were prepared by columbite method. The phase structure of the ceramic samples was analyzed. Results show that the pure perovskite phase is in all ceramics specimens. The effect of the Zr/Ti ratio on the region of morphotropic phase boundary for PZT-PMnN-PSN ceramics was studied. Experimental results show that the phase structure of ceramics changes from tetragonal to rhombohedral with the increase of the content of Zr/Ti ratio in the system. The composition of PZT-PMnN-PSN ceramics near the morphotropic phase boundary obtained is the ratio of Zr/Ti: 49/51. At this ratio, the ceramic has the optimal electromechanical properties: the kp=0.61, the εmax=29520, the d31=-236 pC/N, the Qm=2400, high remanent polarization (Pr=49.2 μC·cm−2, and low coercive field Ec=10.28 kV·cm−1.

  19. Raman selection rules and tensor elements for PMN-0.3PT single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Wanyin; Zhu, Wenliang; Pezzotti, Giuseppe [Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585, Kyoto, Japan and Research Institute for Nanoscience (RIN) Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto (Japan)

    2009-06-15

    Selection rules were put forward theoretically and Raman tensor elements experimentally determined for PMN-0.3PT single-crystal. Such a body of information was then employed to evaluate local domain orientation in a relaxor-based PMN-0.3PT material by means of polarized microprobe Raman spectroscopy. The dependence of Raman spectra upon crystal rotation under different polarized probe configurations was experimentally confirmed by collecting the intensity variation of selected Raman modes on Euler's angle rotation in a poled single-crystal. The periodicity of relative Raman intensity of selected Raman bands revealed symmetry properties. Upon exploiting such properties and with the knowledge of the Raman tensor elements from the A{sub g} and E{sub g} vibrational modes, a viable path becomes available to determine domain texture in relaxor-based PMN-PT materials with high spatial resolution. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Self-Powered Ultrabroadband Photodetector Monolithically Integrated on a PMN-PT Ferroelectric Single Crystal.

    Science.gov (United States)

    Fang, Huajing; Xu, Chao; Ding, Jie; Li, Qiang; Sun, Jia-Lin; Dai, Ji-Yan; Ren, Tian-Ling; Yan, Qingfeng

    2016-12-07

    Photodetectors capable of detecting two or more bands simultaneously with a single system have attracted extensive attentions because of their critical applications in image sensing, communication, and so on. Here, we demonstrate a self-powered ultrabroadband photodetector monolithically integrated on a 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-28PT) single crystal. By combining the optothermal and pyroelectric effect, the multifunctional PMN-28PT single crystal can response to a wide wavelength range from UV to terahertz (THz). At room temperature, the photodetector could generate a pyroelectric current under the intermittent illumination of incident light in absence of external bias. A systematic study of the photoresponse was investigated. The pyroelectric current shows an almost linear relationship to illumination intensity. Benefiting from the excellent pyroelectric property of PMN-28PT single crystal and the optimized device architecture, the device exhibited a dramatic improvement in operation frequency up to 3 kHz without any obvious degradation in sensitivity. Such a self-powered photodetector with ultrabroadband response may open a window for the novel application of ferroelectric materials in optoelectronics.

  1. Influence of the polarization anisotropy on the electrocaloric effect in epitaxial PMN-PT thin films

    Science.gov (United States)

    Mietschke, M.; Chekhonin, P.; Molin, C.; Gebhardt, S.; Fähler, S.; Nielsch, K.; Schultz, L.; Hühne, R.

    2016-09-01

    Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) compounds, which are typically used for high performance actuator applications due to their outstanding piezoelectric properties, show, in addition, a pronounced electrocaloric (EC) effect. The study of epitaxial films is a useful tool to analyze the correlation between the microstructure and EC properties in order to optimize the performance of these materials. Therefore, the 0.9PMN-0.1PT films were grown by a pulsed laser deposition on (001) as well as (111) oriented SrTiO3 single crystalline substrates using a La0.7Sr0.3CoO3 buffer as the bottom electrode and additional Au top electrodes. The structural properties determined by a high resolution X-ray and electron microscopy techniques indicated an undisturbed epitaxial growth. The anisotropy of the ferroelectric domain structure was investigated by a vertical and lateral piezoresponse force microscopy showing clear differences between the two orientations. A significant reduction of the thermal hysteresis was observed in the T-dependent polarization measurements for (111) oriented PMN-PT films, whereas the indirectly determined EC properties yield a maximum ΔT of around 15 K at 40 °C for a field of about 400 kV/cm for both film orientations.

  2. 80-MHz intravascular ultrasound transducer using PMN-PT free-standing film.

    Science.gov (United States)

    Li, Xiang; Wu, Wei; Chung, Youngsoo; Shih, Wan Y; Shih, Wei-Heng; Zhou, Qifa; Shung, K Kirk

    2011-11-01

    [Pb(Mg(1/3)Nb(2/3))O(3)](0.63)[PbTiO(3)](0.37) (PMN-PT) free-standing film of comparable piezoelectric properties to bulk material with thickness of 30 μm has been fabricated using a modified precursor coating approach. At 1 kHz, the dielectric permittivity and loss were 4364 and 0.033, respectively. The remnant polarization and coercive field were 28 μC/cm(2) and 18.43 kV/cm. The electromechanical coupling coefficient k(t) was measured to be 0.55, which was close to that of bulk PMN-PT single-crystal material. Based on this film, high-frequency (82 MHz) miniature ultrasonic transducers were fabricated with 65% bandwidth and 23 dB insertion loss. Axial and lateral resolutions were determined to be as high as 35 and 176 μm. In vitro intravascular imaging on healthy rabbit aorta was performed using the thin film transducers. In comparison with a 35-MHz IVUS transducer, the 80-MHz transducer showed superior resolution and contrast with satisfactory penetration depth. The imaging results suggest that PMN-PT free-standing thin film technology is a feasible and efficient way to fabricate very-high-frequency ultrasonic transducers.

  3. PMN-PT single-crystal high-frequency kerfless phased array.

    Science.gov (United States)

    Chen, Ruimin; Cabrera-Munoz, Nestor E; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K Kirk

    2014-06-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at -6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application.

  4. PMN-PNN-PT单晶的固相法生长研究

    Institute of Scientific and Technical Information of China (English)

    陈克丕; 张孝文

    2007-01-01

    采用两步法和埋入PMN-PT单晶为模板的等离子放电烧结(SPS)技术制备出了致密的单一钙钛矿相的PMN-PNN-PT陶瓷,随后在1200℃下退火100h来诱导晶体的生长。实验结果表明,PMN-PNN-PT单晶〈111〉方向的生长速度明显快于〈001〉方向,而〈111〉方向生长的晶体形状为V字形,这是由钙钛矿结构的生长机理决定的,钙钛矿结构晶体的生长是通过〈001〉方向的层状生长来实现的。

  5. Valence-EELS analysis of local electronic and optical properties of PMN-PT epitaxial film

    Energy Technology Data Exchange (ETDEWEB)

    Kiguchi, Takanori [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)], E-mail: tkiguchi@imr.tohoku.ac.jp; Wakiya, Naoki [Department of Materials Science, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka 432-8561 (Japan); Shinozaki, Kazuo [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan); Konno, Toyohiko J. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2009-04-15

    This study investigated local electrical and optical properties of Pb(Mg{sub 0.39}Nb{sub 0.61})-0.34 mol%PbTiO{sub 3} solid solution (PMN-PT) film stacked on Si (0 0 1) wafer with (La,Sr)CoO{sub 3-x}/CeO{sub 2}/YSZ buffer layers. TEM-VEELS analysis of the PMN-PT thin film, which was grown epitaxially on the Si substrate with two coexisting phases of pseudocubic and tetragonal morphology, was firstly conducted using the TEM-VEELS method. The ELF has shown a bulk plasmon peak and two interband plasmon peaks. The interband transition has been interpreted in comparison with the joint density of state obtained from the measured dielectric function and the density of state calculated by the density functional theory. The interband transition from the O 2p band to Nb 4d/Ti 3d bands determines the optical properties around the band gap. The optical absorption of PMN-PT film has shown the band gap of 3.5 {+-} 0.2 V. The refractive index derived from the TEM-VEELS analysis in the nano-region of the film has agreed with that obtained with the conventional optical measurement from the macroscopic region.

  6. Effects of oxygen ion irradiation on PMN-PT ferroelectric materials for space applications

    Science.gov (United States)

    Guggilla, Padmaja; Batra, A. K.; Powell, Rachel

    2016-09-01

    Lead magnesium niobate-lead titanate (PMN-PT) is an important and high performance piezoelectric and pyroelectric relaxor material having wide range of applications in infrared sensor devices. Present work studies the fabrication and dielectric characteristics of PMN-PT in the bulk form. The PMN-PT bulk material was prepared in sol-gel method and subsequently irradiated with heavy ion oxygen. The materials were analyzed and determined that the relaxorferroelectric material indicated changes in its dielectric constant and pyroelectric coefficient after irradiation. Due to the radiation fluent of 1×1016 ions/cm2, the dielectric constant of the material increased uniformly, while its pyroelectric coefficient showed a sharp increased to the value of 5×10-9 μC/cm2 °C with increase in temperature. Its dielectric constants showed increase in values of 527 μC/cm2 °C at 50°C, 635 μC/cm2 °C at 60°C and 748 μC/cm2 °C at 70°C. Properties such as the material impedance, admittance and modulus were investigated for changes in properties which became evident after irradiation.

  7. Activation of TLR4 is necessary for trauma hemorrhagic shock-induced gut injury and PMN priming

    Science.gov (United States)

    Reino, Diego C.; Palange, David; Feketeova, Elenora; Bonitz, Robert P.; Xu, Da Zhong; Lu, Qi; Sheth, Sharvil U.; Peña, Geber; Ulloa, Luis; De Maio, Antonio; Feinman, Rena; Deitch, Edwin A

    2012-01-01

    Interactions of Toll-like receptors (TLR) with non-microbial factors plays a major role in the pathogenesis of early trauma-hemorrhagic shock (T/HS)-induced organ injury and inflammation. Thus, we tested the hypothesis that TLR4 mutant (TLR4mut) mice would be more resistant to T/HS-induced gut injury and neutrophil (PMN) priming than their wild-type (WT) littermates and found that both were significantly reduced in the TLR4mut mice. Additionally, the in vivo and ex vivo PMN priming effect of T/HS intestinal lymph observed in the WT mice was abrogated in TLR4mut mice as well the TRIFmut deficient mice and partially attenuated in Myd88-/- mice suggesting that TRIF activation played a more predominant role than MyD88 in T/HS lymph-induced PMN priming. PMN depletion studies showed that T/HS lymph-induced acute lung injury (ALI) was PMN-dependent, since lung injury was totally abrogated in PMN-depleted animals. Since the lymph samples were sterile and devoid of endotoxin or bacterial DNA, we investigated whether the effects of T/HS lymph was related to endogenous non-microbial TLR4 ligands. HMGB1, heat shock protein (Hsp)-70, Hsp27 and hyaluronic acid, since all have been implicated in ischemia-reperfusion-induced tissue injury. None of these ‘danger’ proteins appeared to be involved, since their levels were similar between the sham and shock lymph samples. In conclusion, TLR4 activation is important in T/HS-induced gut injury and in T/HS lymph-induced PMN priming and lung injury. However, the T/HS-associated effects of TLR4 on gut barrier dysfunction can be uncoupled from the T/HS lymph-associated effects of TLR4 on PMN priming. PMID:22575992

  8. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

    the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...... Denmark, Odense, DK-5230 Odense M, Denmark   Many migrating passerines emit special calls during nocturnal flight, the so-called flight calls. Several functions of the calls have been suggested but largely remain speculative. Flight calls have been hypothesized to maintain groups during nocturnal...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...

  9. Migratory decisions in birds: Extent of genetic versus environmental control

    Science.gov (United States)

    Ogonowski, M.S.; Conway, C.J.

    2009-01-01

    Migration is one of the most spectacular of animal behaviors and is prevalent across a broad array of taxa. In birds, we know much about the physiological basis of how birds migrate, but less about the relative contribution of genetic versus environmental factors in controlling migratory tendency. To evaluate the extent to which migratory decisions are genetically determined, we examined whether individual western burrowing owls (Athene cunicularia hypugaea) change their migratory tendency from one year to the next at two sites in southern Arizona. We also evaluated the heritability of migratory decisions by using logistic regression to examine the association between the migratory tendency of burrowing owl parents and their offspring. The probability of migrating decreased with age in both sexes and adult males were less migratory than females. Individual owls sometimes changed their migratory tendency from one year to the next, but changes were one-directional: adults that were residents during winter 2004-2005 remained residents the following winter, but 47% of adults that were migrants in winter 2004-2005 became residents the following winter. We found no evidence for an association between the migratory tendency of hatch-year owls and their male or female parents. Migratory tendency of hatch-year owls did not differ between years, study sites or sexes or vary by hatching date. Experimental provision of supplemental food did not affect these relationships. All of our results suggest that heritability of migratory tendency in burrowing owls is low, and that intraspecific variation in migratory tendency is likely due to: (1) environmental factors, or (2) a combination of environmental factors and non-additive genetic variation. The fact that an individual's migratory tendency can change across years implies that widespread anthropogenic changes (i.e., climate change or changes in land use) could potentially cause widespread changes in the migratory tendency of

  10. Overseas seed dispersal by migratory birds.

    Science.gov (United States)

    Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution.

  11. Necrolytic migratory erythema and pancreatic glucagonoma.

    Science.gov (United States)

    Rodríguez, Gerzaín; Vargas, Elga; Abaúnza, Claudia; Cáceres, Sergio

    2016-06-03

    Necrolytic migratory erythema is a rare paraneoplastic dermatosis that may be the first clinical manifestation of the glucagonoma syndrome, a disorder characterized by mucocutaneous rash, glucose intolerance, hypoaminoacidemia, hyperglucagonaemia and pancreatic glucagonoma. The clinical case of a 45-year-old woman is presented. She had been experiencing weight loss, polydipsia, polyphagia, postprandial emesis, excessive hair loss and abdominal pain for two months. Erythematous, scaly and migratory plaques with 20 days of evolution were found on her trunk, perineum, elbows, hands, feet, inframammary and antecubital folds. The skin biopsy revealed noticeable vacuolar changes in high epidermal cells, extensive necrosis and thin orthokeratotic cornified layer. These findings pointed to a diagnosis of necrolytic migratory erythema. A suggestion was made to investigate a pancreatic glucagonoma. Laboratory tests showed moderate anemia, hyperglycemia and marked hyperglucagonaemia. Abdominal ultrasound revealed a mass in the tail of the pancreas measuring 6 x 5 x 5 cm which was resected. The histopathological findings were compatible with a diagnosis of glucagonoma, as confirmed by immunohistochemistry. Skin symptoms disappeared 10 days after the tumor resection. We can conclude that the histological changes defined may be clues that can lead the search for a distant skin disease and allow for its diagnosis. The histological pattern of vacuolation and epidermal necrosis should arouse suspicion of pancreatic glucagonoma.

  12. Pyroelectric and electrocaloric effect of <1 1 1>-oriented 0.9PMN-0.1PT single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Luo Laihui, E-mail: llhsic@126.com [Department of Physics, Ningbo University, Ningbo 315211 (China); Chen Hongbing [Institute of Materials Science and Engineering, Ningbo University, Ningbo 315211 (China); Zhu Yuejin; Li Weiping [Department of Physics, Ningbo University, Ningbo 315211 (China); Luo Haosu [Shanghai Institute of ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang Yuepin [Department of Physics, Ningbo University, Ningbo 315211 (China)

    2011-08-11

    Highlights: > Here, we use indirect method to measure pyroelectric and electrocaloric effect. > The largest temperature change achieves {approx}1 deg. C with a small field change. > The mechanism of electrocaloric effect of PMN-PT is explained. > The largest ({partial_derivative}P/{partial_derivative}T){sub E} value achieves -0.5 {mu}C/cm{sup 2} K. > PMN-PT has excellent pyroelectric effect. - Abstract: In this paper, the polarization vs. electric field hysteresis loops of <1 1 1>-oriented 0.9PbMg{sub 1/3}Nb{sub 2/3}O{sub 3}-0.1PbTiO{sub 3} (0.9PMN-0.1PT) single crystal at different temperatures (20-110 deg. C) were measured. The adiabatic temperature change {Delta}T of <1 1 1>-oriented 0.9PMN-0.1PT single crystal due to the application or withdraw of electric field were calculated through the thermodynamic relation. The largest temperature change {Delta}T achieves {approx}1 K with only a change of 40 kV/cm electric field, the mechanism of the electrocaloric effect (ECE) is discussed for 0.9PMN-0.1PT crystal. The pyroelectric coefficient of 0.9PMN-0.1PT under bias field was calculated according to the data of hysteresis loop. The result shows that 0.9PMN-0.1PT have large pyroelectric coefficient under bias field, the largest ({partial_derivative}P/{partial_derivative}T){sub E} value achieves -0.5 {mu}C/cm{sup 2} K.

  13. Pyrochlore free 0.67PMN-0.33PT ceramics prepared by particle-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Ruiqing; Li, Yan [College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China); Gong, Shuwen [College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059 (China); Liu, Yong [College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China); Li, Guorong [The State Key Lab of High Performance Ceramics and Superfinemicrostructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China); Xu, Zhijun, E-mail: zhjxu@lcu.edu.cn [College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059 (China)

    2012-08-20

    Highlights: Black-Right-Pointing-Pointer Pyrochlore-free PMN-PT powders were obtained by two-step particle-coating method. Black-Right-Pointing-Pointer Mg-citric acid polymeric complex coatings avoid the formation of pyrochlore phase. Black-Right-Pointing-Pointer Pyrochlore-free PMN-PT powders have been successfully prepared at 800 Degree-Sign C. Black-Right-Pointing-Pointer The PMN-PT ceramics sintered at 1150 Degree-Sign C exhibited excellent electrical properties. - Abstract: In present study, pyrochlore-free 0.67Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.33PbTiO{sub 3} (0.67PMN-0.33PT) powders and ceramics have been successfully prepared. Using oxides as raw materials, pyrochlore-free 0.67PMN-0.33PT powders were obtained by two-step particle-coating method. The XRD and EDS results confirmed that the Mg-citric acid polymeric complex coatings effectively prevent the direct contact between PbO and Nb{sub 2}O{sub 5} and thus avoid the formation of pyrochlore phase. The obtained pyrochlore-free 0.67PMN-0.33PT powders at 800 Degree-Sign C showed uniform and even grain size. The 0.67PMN-0.33PT ceramics sintered at 1150 Degree-Sign C for 2 h exhibited 99% of relative density and a piezoelectric coefficient (d{sub 33}) of 576pC/N, a remnant polarization (P{sub r}) of 28.4 {mu}C/cm{sup 2}, a planar electromechanical coupling factor (k{sub p}) of 0.55 and a mechanical quality factor (Q{sub m}) of 90.

  14. PMN-PT弛豫型铁电材料的凝固组织与相结构%Solidified microstructure and phase structure of relaxor ferroelectrics PMN-PT

    Institute of Scientific and Technical Information of China (English)

    惠增哲; 刘改琳; 刘江南; 杨通

    2002-01-01

    采用熔融法制备了PMN-32PT弛豫型铁电晶粒,研究了自由凝固条件下PMN-32PT晶体的生长形貌、组织形态、相结构和择优生长方向.结果表明,自由凝固条件下,从熔体中生长出的PMN-32PT晶体一般呈现三棱柱和八面体两种形态;PMN-32PT晶体的择优生长方向为晶向;凝固过程中熔剂不足会引起组分中MgO的优先树枝状结晶;生长速度对PMN-32PT晶体的完整性有较大影响,生长速度过快会导致熔剂夹杂.

  15. 两步无机盐-凝胶法制备PMN-PT弛豫铁电陶瓷粉体%Preparation of Pyrochlore-Free PMN-PT Powder by a Two-Stage Polymerized Complex Method

    Institute of Scientific and Technical Information of China (English)

    陈晋; 樊慧庆; 邱少君; 王志银

    2007-01-01

    0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3(简称:PMN-PT)弛豫铁电粉体采用两步无机盐-凝胶法制备.以氧化镁,醋酸铅,钛酸丁脂为原料,柠檬酸为螯合剂,乙二醇为溶剂,分别合成稳定的Mg,Pb-Ti的有机化合物先驱体溶液.Nb2O5粉体与Mg先驱体溶液均匀混合,并采用溶胶-凝胶工艺制备MgNb2O6(MN)先驱体粉体;MN粉体与Pb-Ti先驱体溶液均匀混合,并制备PMN-PT粉体.通过XRD和SEM分析PMN-PT钙钛矿相形成的影响因素和微观形貌,研究全钙钛矿相PMN-PT铁电粉体的制备.结果表明:过量3%MgO前驱体经1050℃,4 h煅烧可以得到纯相MgNb2O6先驱体粉体;过量5%PbO前驱体经900℃,4 h煅烧可以得到全钙钛矿相PMN-PT粉体.

  16. Abnormal dielectric characteristics of PMN-32% PT single crystal under dc bias

    Institute of Scientific and Technical Information of China (English)

    XI Zengzhe; LI Zhenrong; XU Zhuo; ZHANG Liangying; YAO Xi

    2003-01-01

    The dielectric properties and phase transition behavior of the [001] and [111] oriented PMN-32%PT single crystal under the different dc bias (E) have been investigated as a function of temperatures. Under the application of dc bias ranging from 1.5 to 4.0 kV/cm, the dielectric spectrum of a [001] oriented single crystal showed an abnormal dielectric peak within the rhombic phase-stable temperature range.However, this peak disappeared at E>4.0 kV/cm and was not yet found in the [111] oriented single crystal. The abnormal dielectric peak was attributed to the filed-induced phase transition.

  17. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    OpenAIRE

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2014-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at ...

  18. Escaping peril: perceived predation risk affects migratory propensity

    DEFF Research Database (Denmark)

    Hulthén, Kaj; Chapman, Ben B.; Nilsson, P. Anders;

    2015-01-01

    to record the migration of individual roach (Rutilus rutilus), a partially migratory fish, in the wild following exposure to manipulation of direct (predator presence/absence) and indirect (high/low roach density) perceived predation risk in experimental mesocosms. Following exposure, we released fish......) affected timing but not propensity showing that elevated risk carried over to alter migratory behaviour in the wild. Our key finding demonstrates predator-driven migratory plasticity, highlighting the powerful role of predation risk for migratory decision-making and dynamics....

  19. Importance of reservoir tributaries to spawning of migratory fish in the upper Paraná River

    Science.gov (United States)

    da Silva, P.S.; Makrakis, Maristela Cavicchioli; Miranda, Leandro E.; Makrakis, Sergio; Assumpcao, L.; Paula, S.; Dias, João Henrique Pinheiro; Marques, H.

    2015-01-01

    Regulation of rivers by dams transforms previously lotic reaches above the dam into lentic ones and limits or prevents longitudinal connectivity, which impairs access to suitable habitats for the reproduction of many migratory fish species. Frequently, unregulated tributaries can provide important habitat heterogeneity to a regulated river and may mitigate the influence of impoundments on the mainstem river. We evaluated the importance of tributaries to spawning of migratory fish species over three spawning seasons, by comparing several abiotic conditions and larval fish distributions in four rivers that are tributaries to an impounded reach of the Upper Parana River, Brazil. Our study confirmed reproduction of at least 8 long-distance migrators, likely nine, out of a total of 19 occurring in the Upper Parana River. Total larval densities and percentage species composition differed among tributaries, but the differences were not consistent among spawning seasons and unexpectedly were not strongly related to annual differences in temperature and hydrology. We hypothesize that under present conditions, densities of larvae of migratory species may be better related to efficiency of fish passage facilities than to temperature and hydrology. Our study indicates that adult fish are finding suitable habitat for spawning in tributaries, fish eggs are developing into larvae, and larvae are finding suitable rearing space in lagoons adjacent to the tributaries. Our findings also suggest the need for establishment of protected areas in unregulated and lightly regulated tributaries to preserve essential spawning and nursery habitats.

  20. PMN-PT透明光电陶瓷材料的特性及制备技术%Characteristic and Fabrication Technology of Transparent Electrooptic PMN-PT Ceramic Material

    Institute of Scientific and Technical Information of China (English)

    姜德生; 刘忠明; 童杏林; 刘恋

    2007-01-01

    以传统的光电材料铌酸锂晶体和透明光电陶瓷材料PLZT(镧改性的锆钛酸铅固熔体)作为比较,介绍了铌镁酸铅(PMN)-钛酸铅(PT)(简称PMN-PT)光电透明陶瓷的结构和性能优势,主要介绍了PMN-PT各种粉末的制备方法、烧结工艺方法及其各自的特点,同时对影响陶瓷透明的因素和基于该材料的器件和应用进行了简要介绍.

  1. Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) Material for Actuator Applications

    OpenAIRE

    Hana Uršič; Marina Santo Zarnik; Marija Kosec

    2011-01-01

    Due to its large piezoelectric and electrostrictive responses to an applied electric field the (1−x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN-PT) solid solution has been widely investigated as a promising material for different actuator applications. This paper discusses some of the recent achievements in the field of PMN-PT piezoelectric and electrostrictive actuators manufactured from PMN-PT single crystals, bulk ceramics, or thick films. The functional properties of PMN-PT materials and some represent...

  2. 76 FR 59298 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Science.gov (United States)

    2011-09-26

    ... Survey; population status reports for blue-winged teal, sandhill cranes, woodcock, mourning doves, white... has reviewed this rule under Executive Order 12866. OMB bases its determination of regulatory... of age or older must carry on his/her person a valid Migratory Bird Hunting and Conservation...

  3. 76 FR 69223 - Migratory Bird Permits; Definition of “Hybrid” Migratory Bird

    Science.gov (United States)

    2011-11-08

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX90 Migratory Bird Permits; Definition of ``Hybrid.... Fish and Wildlife Service (Service), propose to revise the definition of ``hybrid'' as it relates to.... This definition has created difficulties because it differs from the longstanding Service...

  4. 78 FR 65576 - Migratory Bird Permits; Definition of “Hybrid” Migratory Bird

    Science.gov (United States)

    2013-11-01

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX90 Migratory Bird Permits; Definition of ``Hybrid... and Wildlife Service (FWS), revise the definition of ``hybrid'' as it relates to birds protected under.... The definition of ``hybrid'' we are codifying is already in use by the Service in other...

  5. 78 FR 58123 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2013-09-20

    ... Flyway-Council system of migratory bird management has been a longstanding example of State-Federal... allowed to continue in an experimental status to allow for additional data collection (75 FR 58250... Conservation Order (CO) activities in the Rainwater Basin (RWB) area of Nebraska, which is implemented...

  6. Assessing allowable take of migratory birds

    Science.gov (United States)

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be

  7. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

    Directory of Open Access Journals (Sweden)

    Rymantas J. Kazys

    2017-01-01

    Full Text Available Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

  8. (1-χ)PMN-χPT陶瓷材料弛豫性研究

    Institute of Scientific and Technical Information of China (English)

    吴宁宁; 宋雪梅; 侯育冬; 朱满康; 王超; 严辉

    2008-01-01

    传统弛豫性研究认为(1-χ)Pb(Mg1/3Nb2/3)O3-χPbTiO3(PMN-PT)二元体系的弛豫性随PT含量的增加呈简单线性减小关系,而没有对准同型相界(MPB)附近的弛豫性具体研究.本研究通过对PMN-PT陶瓷材料的研究表明:在准同型相界χ=0.32)附近,弥散因子γ值最大,弛豫性最强;在三方相和四方相附近弛豫性逐渐减弱.此种弛豫性变化的主要原因是由于准同型相界的畴结构复杂,形成新的有序纳米微畴,引起MPB组成弛豫性明显增强.通过电滞回线和Raman光谱对弛豫性的变化规律进行验证,结果都表明弛豫性在MPB处呈现明显升高的趋势.验证了该实验弛豫性变化规律的正确性.

  9. SrTiO3 on piezoelectric PMN-PT(001) for application of variable strain

    Energy Technology Data Exchange (ETDEWEB)

    Bilani-Zeneli, Orkidia [IFW Dresden; Rata, D [IFW Dresden; Herklotz, A [IFW Dresden; Mieth, O [Technische Universitat Dresden; Eng, L. M. [TU Dresden; Schultz, Ludwig [Institut fur Metallische Werkstoffe, Dresden, Germany; Biegalski, Michael D [ORNL; Christen, Hans M [ORNL; Dorr, Kathrin [IFW Dresden

    2008-01-01

    SrTiO3 (STO) is the most frequently used substrate material for complex oxide films. In this work, STO is explored as a buffer layer on piezoelectric pseudocubic Pb(Mg1/3Nb2/3)0.72Ti0.28O3(001) (PMN-PT) substrates which serve to reversibly strain thin films. The STO buffer layer reduces the in-plane lattice parameter and allows for better lattice matching to broader range of thin film materials. STO films (30 nm) have been grown with epitaxial orientation on PMN-PT with an in-plane lattice parameter close to that of bulk STO. The substrate`s rhombohedral domain structure has been imaged by Atomic Force Microscopy (AFM). The related ferroelectric domain structure has been investigated by Piezoresponse Force Microscopy (PFM). Within a domain, STO grows with rather low roughness (rms < 0.2 nm). The transfer of the piezoelectric substrate strain to the STO film and its variation with an applied electric field is studied by x-ray diffraction. The strain dependence of the electrical resistance is measured for a ferromagnetic manganite film grown on top of the STO. Both experiments confirm qualitatively that the STO buffer transfers the substrate strain into a functional film deposited on top.

  10. Mechanical confinement for tuning ferroelectric response in PMN-PT single crystal

    Science.gov (United States)

    Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

    2015-02-01

    Ferroelectrics form an important class of materials and are employed for a variety of applications. However, specific applications dictate the need of tailored ferroelectric response. This creates a requirement to obtain ferroelectric materials with tunable properties. Generally, chemical modifications or domain engineering are employed to this effect. This study attempts to shed light on the use of compressive pre-stresses for tuning and enhancing the ferroelectric properties. For the purpose, polarization versus electric field hysteresis data for 68Pb(Mn1/3Nb2/3)O3-32PbTiO3 (PMN-PT) single crystals were obtained as a function of uniaxial compressive stresses and operating temperatures. These data were utilized to investigate the effects of mechanical confinement for four individual case studies of electrocaloric effect, electrical energy storage, pyroelectric, and piezoelectric effect. A significant improvement was obtained for all case studies. The adiabatic temperature change was improved by ≈80% (28 MPa, 353 K); energy storage density increased by a factor of five (28 MPa, 353 K); pyroelectric figure of merits improved by an order of magnitude (21 MPa) and the piezoelectric coefficient was tailored (variable stress). The results offer promising insight into the use of directional confinement for improving application specific ferroelectric properties in PMN-PT single crystal.

  11. Magnetoelectric properties of epitaxial Fe3O4 thin films on (011) PMN-PT piezosubstrates

    Science.gov (United States)

    Tkach, Alexander; Baghaie Yazdi, Mehrdad; Foerster, Michael; Büttner, Felix; Vafaee, Mehran; Fries, Maximilian; Kläui, Mathias

    2015-01-01

    We determine the magnetic and magnetotransport properties of 33 nm thick Fe3O4 films epitaxially deposited by rf-magnetron sputtering on unpoled (011) [PbMg1/3Nb2/3O3] 0.68-[PbTiO3]0.32 (PMN-PT) substrates. The magnetoresistance (MR), as well as the magnetization reversal, strongly depend on the in-plane crystallographic direction of the epitaxial (011) Fe3O4 film and strain. When the magnetic field is applied along [100], the magnetization loops are slanted and the sign of the longitudinal MR changes from positive to negative around the Verwey transition at 125 K on cooling. Along the [01 1 ¯] direction, the loops are square shaped and the MR is negative above the switching field across the whole temperature range, just increasing in absolute value when cooling from 300 K to 150 K. The value of the MR is found to be strongly affected by poling the PMN-PT substrate, decreasing in the [100] direction and slightly increasing in the [01 1 ¯] direction upon poling, which results in a strained film.

  12. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

    Science.gov (United States)

    Kazys, Rymantas J.; Sliteris, Reimondas; Sestoke, Justina

    2017-01-01

    Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz) wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space. PMID:28067807

  13. Dielectric behavior and phase transition of perovskite PMN-PT films

    Energy Technology Data Exchange (ETDEWEB)

    Fan Huiqing; Chen Jin, E-mail: hqfan3@163.co [State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)

    2010-05-01

    The dielectric properties of perovskite relaxor ferroelectrics 0.80Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.20PbTiO{sub 3} (0.80PMN-0.20PT) thick films fabricated by electrophoretic deposition were investigated as a function of temperature and frequency. The phase transformation of 0.80PMN-0.20PT thick films has two different kinds of phase transition: one is a diffused phase transition around the temperature of dielectric permittivity maxima and the other is a first-order transition from frequency dispersion relaxor ferroelectrics to normal ferroelectrics. The frequency and temperature dependence of the dielectric permittivity maximum was also analyzed to discuss the physical meaning of the Debey, Vogel-Fulcher (V-F) and new-glass (N-G) relations. It is shown that the N-G relation is more suitable to characterize the relaxation behavior than the Debey and V-F relations.

  14. Strain-coupled multiferroic model system of magnetic films on piezoelectric PMN-PT(001)

    Energy Technology Data Exchange (ETDEWEB)

    Herklotz, Andreas; Rata, Diana; Boldyreva, Ksenia; Bilani-Zeneli, Orkidia; Dekker, Martina Cornelia; Schultz, Ludwig; Doerr, Kathrin [IFW Dresden (Germany)

    2009-07-01

    In many multiferroic composites the interrelation of magnetic and polar electric properties originates from joined elastic strain of the components. A straightforward model system for quantitative investigations of strain-modulated magnetic properties comprises of magnetic films epitaxially grown on high-strain piezoelectric single crystals. In this work, we report on structural, ferroelectric and elastic properties of Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} (PMN-PT) (001) single crystals utilized as thin film substrates for dynamical strain control of up to 0.25% in complex oxide films. A tunable buffer layer system of solid solutions of perovskite-type LaScO{sub 3} and LaAlO{sub 3} has been developed that serves to adjust the in-plane parameter of buffered PMN-PT in a range of several percent. Thus, various as-grown strain states of a given magnetic film can be prepared and studied under reversible strain. First examples for La{sub 1-x}Sr{sub x}BO{sub 3} (B=Co or Mn) films under both statically and dynamically varied biaxial strain will be discussed.

  15. Micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular array.

    Science.gov (United States)

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K Kirk

    2012-04-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9×9 μm. The width of the kerf among pillars was ∼5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm(2) with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers, e.g. 1D and 2D arrays.

  16. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals.

    Science.gov (United States)

    Kazys, Rymantas J; Sliteris, Reimondas; Sestoke, Justina

    2017-01-06

    Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz) wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer -11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

  17. 过量PbO、MgO对PMN-PT陶瓷介电性能的影响%The effect of excess PbO and MgO on dielectric property of PMN-PT

    Institute of Scientific and Technical Information of China (English)

    刘霞; 曹万强

    2006-01-01

    为减少焦绿石相,采用二次合成法制备0.67PMN-0.33PT陶瓷,研究过量PbO、MgO对0.67PMN-0.33PT陶瓷结构和介电性能的影响.结果表明,过量PbO和MgO都能减少介电损耗,但是过量PbO同时降低了介电常数.过量PbO和过量MgO对样品的相变温度Tm没有影响.

  18. Thermal-independent properties of PIN-PMN-PT single-crystal linear-array ultrasonic transducers.

    Science.gov (United States)

    Chen, Ruimin; Wu, Jinchuan; Ho Lam, Kwok; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K Kirk

    2012-12-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In(1/2)Nb(1/2))-Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PIN-PMN-PT) and binary Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PMNPT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a -6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising.

  19. Numerical Calculation of SAW Propagation Properties at the x-Cut of Ferroelectric PMN-33%PT Single Crystals

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LI Xiu-Ming; ZHANG Rui; HUANG Nai-Xing; CAO Wen-Wu

    2009-01-01

    Surface acoustic wave (SAW) properties at the x-cut of relaxor-based 0.67Pb(Mg1/3 Nb2/3) Oa-O.33Pb TiO3 (PMN-33%PT) ferroelectric single crystals are analyzed theoretically when poled along the[O01]c cubic direction.It can be found that PMN-33%PT single crystal is a kind of material with a low phase velocity and high electromechanical coupling coefficient,and the single crystal possesses some cuts with zero power flow angle.The results are based on the material parameters at room temperature.The conclusions provide device designers with a few ideal cuts of PMN-33%PT single crystals.Moreover,choosing an optimal cut will dramatically improve the performance of SAW devices,and corresponding results for crystal systems working at other temperatures could also be figured out by employing the method.

  20. 相组成对PMN-PT陶瓷压电性能的影响%Influence of Phase Composition on the Piezoelectric Properties of PMN-PT Ceramic

    Institute of Scientific and Technical Information of China (English)

    朱为民; 李承恩; 郭存济; 颜莉华

    2001-01-01

    研究了PMN-PT陶瓷在准同型相界(MPB)区域、不同烧结温度下,化学组成、相组成对陶瓷压电性能的影响.发现对于同一化学组成的陶瓷,随着烧结温度的上升,发生了菱方相→四方相的相转变,同时随着菱方相、四方相相比例的接近,陶瓷的压电性能有显著的提高.而在不同烧结温度下,最佳压电性能所对应的化学组成有微小的变化.据此认为,陶瓷的压电性能不仅与化学组成有关,而且与相组成也密切相关,随着烧结温度的变化,发生了准同型相界的微小移动

  1. 准同型相界附近PMN-PT陶瓷的介电性能%Dielectric Properties of PMN-PT Ceramics Near the Morphotropic Phase Boundary

    Institute of Scientific and Technical Information of China (English)

    曹林洪; 姚熹; 徐卓

    2007-01-01

    采用铌铁矿预产物合成法制备了组成在相界附近的(1-x) Pb(Mg1/3Nb2/3)O3-x PbTiO3 (PMN-PT)弛豫铁电陶瓷.陶瓷样品X-射线衍射相组成和相结构分析表明:所有陶瓷样品均为纯钙钛矿相,无任何其他杂相出现;且组成在x=0.33处存在一准同型相界(MPB),在该相界附近三方相和四方相共存,而远离该相界则分别为纯三方相和四方相.相界附近组成随PT摩尔分数增加,介电峰变得尖锐,频率弥散减弱,即介电弛豫程度减弱.这主要是由于四方相增多,三方相减少,从而使弛豫铁电体变为正常铁电体.

  2. 氟取代PMN-PT陶瓷的制备与性能研究%Research on Preparation and Properties of Fluorine Substituted PMN-PT Ceramics

    Institute of Scientific and Technical Information of China (English)

    曹林洪; 徐卓; 姚熹; 张瑞明; 李岩

    2007-01-01

    以PbF2为氟源,采用半化学法成功制备了钙钛矿相的F取代PMN-PT陶瓷.随F含量增加,陶瓷的体积密度增大.与含F试样相比,无F试样的晶粒较大,约10 μm,介电常数峰和介电损耗峰都很尖锐,而且峰值介电常数异常高,约45000,其电滞回线矩形度高,剩余极化强度高,约30μC/cm2,其压电常数较高,约420 pC/N;但在含F试样中,含摩尔分数2%F试样具有较好的显微结构、介电和压电性能.其晶粒约2~3 μm,峰值介电常数约30000,剩余极化强度接近30μC/cm2,压电常数约380 pC/N.

  3. Sensory neuropathy in progressive motor neuronopathy (pmn) mice is associated with defects in microtubule polymerization and axonal transport.

    Science.gov (United States)

    Schäfer, Michael K; Bellouze, Sarah; Jacquier, Arnaud; Schaller, Sébastien; Richard, Laurence; Mathis, Stéphane; Vallat, Jean-Michel; Haase, Georg

    2016-08-04

    Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter mice and electron microscopy, we demonstrate axonal discontinuities, bead-like spheroids and ovoids in pmn suralis nerves indicating prominent sensory neuropathy. The axonal alterations qualitatively resemble those in phrenic motor nerves but do not culminate in the loss of myelinated fibers. We further show that the pmn mutation decreases the level of TBCE, impedes microtubule polymerization in dorsal root ganglion (DRG) neurons and causes progressive loss of microtubules in large and small caliber suralis axons. Live imaging of axonal transport using GFP-tagged tetanus toxin C-fragment (GFP-TTC) demonstrates defects in microtubule-based transport in pmn DRG neurons, providing a potential explanation for the axonal alterations in sensory nerves. This study unravels sensory neuropathy as a pathological feature of mouse pmn, and discusses the potential contribution of cytoskeletal defects to sensory neuropathy in human motor neuron disease.

  4. The glucagonoma syndrome and necrolytic migratory erythema : A clinical review

    NARCIS (Netherlands)

    van Beek, André P.; de Haas, Ellen R.M.; van Vloten, Willem A.; Lips, Cees J.M.; Roijers, Janine F.M.; Canninga-van Dijk, Marijke R.

    2004-01-01

    The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently

  5. The glucagonoma syndrome and necrolytic migratory erythema: A clinical review

    NARCIS (Netherlands)

    van Beek, André P.; de Haas, Ellen R.M.; van Vloten, Willem A.; Lips, Cees J.M.; Roijers, Janine F.M.; Canninga-van Dijk, Marijke R.

    2004-01-01

    The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently

  6. Heterochrony in the Act: The Migratory Politics of Time

    NARCIS (Netherlands)

    Bal, M.; Stevonić, I.

    2012-01-01

    The article explores video art engagement and migratory culture through an analysis of a few works relating to it. It is proposed that an engagement with current migratory culture represents a key to understanding processes of actuality of viewing and actuality of the transformations in which hetero

  7. 76 FR 39368 - Migratory Bird Permits; Abatement Regulations

    Science.gov (United States)

    2011-07-06

    ... migratory bird abatement permit. On January 12, 2007, we published a Federal Register notice (72 FR 1556..., we published a Federal Register notice (72 FR 69705-69706) announcing final permit conditions. This... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement...

  8. The glucagonoma syndrome and necrolytic migratory erythema : A clinical review

    NARCIS (Netherlands)

    van Beek, André P.; de Haas, Ellen R.M.; van Vloten, Willem A.; Lips, Cees J.M.; Roijers, Janine F.M.; Canninga-van Dijk, Marijke R.

    2004-01-01

    The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently

  9. Migratory birds reinforce local circulation of avian influenza viruses

    NARCIS (Netherlands)

    Verhagen, J.H.G.; Van Dijk, J.G.B.; Vuong, O.; Lexmond, P.; Klaassen, M.R.J.; Fouchier, R.A.M

    2014-01-01

    Migratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV) in wild birds, has largel

  10. Migratory birds reinforce local circulation of avian influenza viruses

    NARCIS (Netherlands)

    J.H. Verhagen (Josanne); J.G.B. Dijk (Jacintha); O. Vuong (Spronken); T.M. Bestebroer (Theo); P. Lexmond (Pascal); M. Klaassen (Marcel); R.A.M. Fouchier (Ron)

    2014-01-01

    textabstractMigratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV) in wild birds

  11. REPORT TO THE PRESIDENT ON DOMESTIC MIGRATORY FARM LABOR.

    Science.gov (United States)

    MITCHELL, JAMES P.

    THE OBJECTIVES OF THE PRESIDENT'S COMMITTEE ON MIGRATORY LABOR ARE TO BRING ABOUT IMPROVED CONDITIONS FOR MIGRATORY WORKERS TO MIGRATE BY STABILIZING AGRICULTURAL EMPLOYMENT. EFFORTS HAVE BEEN DIRECTED TOWARD RESOLVING PROBLEMS OF CAMP HOUSING, SAFE TRANSPORTATION, ADEQUATE EDUCATION AND HEALTH SERVICES, EXTENSION OF LABOR LAWS TO AGRICULTURAL…

  12. Is there a "migratory syndrome" common to all migrant birds?

    NARCIS (Netherlands)

    Piersma, T; Perez-Tris, J; Mouritsen, H; Bauchinger, U; Bairlein, F; Bauchinger, U; Goymann, W; JenniEiermann, S

    2005-01-01

    Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory syndrome,

  13. Migratory birds reinforce local circulation of avian influenza viruses.

    Science.gov (United States)

    Verhagen, Josanne H; van Dijk, Jacintha G B; Vuong, Oanh; Bestebroer, Theo; Lexmond, Pascal; Klaassen, Marcel; Fouchier, Ron A M

    2014-01-01

    Migratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV) in wild birds, has largely remained unstudied. During an autumn H3 LPAIV epizootic in free-living mallards (Anas platyrhynchos) - a partially migratory species - we identified resident and migratory host populations using stable hydrogen isotope analysis of flight feathers. We investigated the role of migratory and resident hosts separately in the introduction and maintenance of H3 LPAIV during the epizootic. To test this we analysed (i) H3 virus kinship, (ii) temporal patterns in H3 virus prevalence and shedding and (iii) H3-specific antibody prevalence in relation to host migratory strategy. We demonstrate that the H3 LPAIV strain causing the epizootic most likely originated from a single introduction, followed by local clonal expansion. The H3 LPAIV strain was genetically unrelated to H3 LPAIV detected both before and after the epizootic at the study site. During the LPAIV epizootic, migratory mallards were more often infected with H3 LPAIV than residents. Low titres of H3-specific antibodies were detected in only a few residents and migrants. Our results suggest that in this LPAIV epizootic, a single H3 virus was present in resident mallards prior to arrival of migratory mallards followed by a period of virus amplification, importantly associated with the influx of migratory mallards. Thus migrants are suggested to act as local amplifiers rather than the often suggested role as vectors importing novel strains from afar. Our study exemplifies that a multifaceted interdisciplinary approach offers promising opportunities to elucidate the role of migratory and resident hosts in infectious disease dynamics in wildlife.

  14. Migratory birds reinforce local circulation of avian influenza viruses.

    Directory of Open Access Journals (Sweden)

    Josanne H Verhagen

    Full Text Available Migratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV in wild birds, has largely remained unstudied. During an autumn H3 LPAIV epizootic in free-living mallards (Anas platyrhynchos - a partially migratory species - we identified resident and migratory host populations using stable hydrogen isotope analysis of flight feathers. We investigated the role of migratory and resident hosts separately in the introduction and maintenance of H3 LPAIV during the epizootic. To test this we analysed (i H3 virus kinship, (ii temporal patterns in H3 virus prevalence and shedding and (iii H3-specific antibody prevalence in relation to host migratory strategy. We demonstrate that the H3 LPAIV strain causing the epizootic most likely originated from a single introduction, followed by local clonal expansion. The H3 LPAIV strain was genetically unrelated to H3 LPAIV detected both before and after the epizootic at the study site. During the LPAIV epizootic, migratory mallards were more often infected with H3 LPAIV than residents. Low titres of H3-specific antibodies were detected in only a few residents and migrants. Our results suggest that in this LPAIV epizootic, a single H3 virus was present in resident mallards prior to arrival of migratory mallards followed by a period of virus amplification, importantly associated with the influx of migratory mallards. Thus migrants are suggested to act as local amplifiers rather than the often suggested role as vectors importing novel strains from afar. Our study exemplifies that a multifaceted interdisciplinary approach offers promising opportunities to elucidate the role of migratory and resident hosts in infectious disease dynamics in wildlife.

  15. Current selection for lower migratory activity will drive the evolution of residency in a migratory bird population.

    Science.gov (United States)

    Pulido, Francisco; Berthold, Peter

    2010-04-20

    Global warming is impacting biodiversity by altering the distribution, abundance, and phenology of a wide range of animal and plant species. One of the best documented responses to recent climate change is alterations in the migratory behavior of birds, but the mechanisms underlying these phenotypic adjustments are largely unknown. This knowledge is still crucial to predict whether populations of migratory birds will adapt to a rapid increase in temperature. We monitored migratory behavior in a population of blackcaps (Sylvia atricapilla) to test for evolutionary responses to recent climate change. Using a common garden experiment in time and captive breeding we demonstrated a genetic reduction in migratory activity and evolutionary change in phenotypic plasticity of migration onset. An artificial selection experiment further revealed that residency will rapidly evolve in completely migratory bird populations if selection for shorter migration distance persists. Our findings suggest that current alterations of the environment are favoring birds wintering closer to the breeding grounds and that populations of migratory birds have strongly responded to these changes in selection. The reduction of migratory activity is probably an important evolutionary process in the adaptation of migratory birds to climate change, because it reduces migration costs and facilitates the rapid adjustment to the shifts in the timing of food availability during reproduction.

  16. Unique role for ATG5 in PMN-mediated immunopathology during M. tuberculosis infection

    Science.gov (United States)

    Kimmey, Jacqueline M.; Huynh, Jeremy P.; Weiss, Leslie A.; Park, Sunmin; Kambal, Amal; Debnath, Jayanta; Virgin, Herbert W.; Stallings, Christina L.

    2015-01-01

    Summary Paragraph Mycobacterium tuberculosis (Mtb), a major global health threat, replicates in macrophages (MΦ) in part by inhibiting phagosome-lysosome fusion, until IFN-γ activates the MΦ to traffic Mtb to the lysosome. How IFN-γ elicits this effect is unknown, but many studies suggest a role for macroautophagy (autophagy herein), a cellular process by which cytoplasmic contents are sequestered into an autophagosome and targeted for lysosomal degradation1. The involvement of autophagy has been defined based on studies in cultured MΦ or dendritic cells (DC) where Mtb colocalizes with autophagy (ATG) factors ATG5, ATG12, ATG16L1, p62, NDP52, Beclin1 and LC32–6, stimulation of autophagy increases bacterial killing6–8, and inhibition of autophagy allows for increased bacterial survival1,2,4,6,7. Notably, these studies reveal modest (e.g. 1.5- to 3-fold change) effects on Mtb replication. In contrast, Atg5fl/fl-LysM-Cre mice lacking ATG5 in monocyte-derived cells and neutrophils (polymorphic mononuclear cells, PMN) succumb to Mtb within 30 days4,9, an extremely severe phenotype similar to mice lacking IFN-γ signaling10,11. Importantly, ATG5 is the only ATG factor that has been studied during Mtb infection in vivo and autophagy-independent functions of ATG5 have been described12–18. For this reason, we used a genetic approach to elucidate the role for multiple ATG genes and the requirement for autophagy in resistance to Mtb infection in vivo. We have discovered that, contrary to expectation, autophagic capacity does not correlate with the outcome of Mtb infection. Instead, ATG5 plays a unique role in protection against Mtb by preventing PMN-mediated immunopathology. Furthermore, while ATG5 is dispensable in alveolar MΦ during Mtb infection, loss of Atg5 in PMN can sensitize mice to Mtb. These findings shift our understanding of the role of ATG5 during Mtb infection, reveal a new outcome of ATG5 activity, and shed light on early events in innate immunity

  17. Visual Impairment

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Visual Impairment KidsHealth > For Teens > Visual Impairment Print A A ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual problem ...

  18. PMN-PT系统中偏置电场诱导压电效应的研究%Investigation of Bias-Voltage Induced Piezoelectric Effects in PMN-PT Ceramics

    Institute of Scientific and Technical Information of China (English)

    宋尚军; 吕忆农; 陆佩文; 曾燕伟

    2004-01-01

    通过测定PMN-PT系统中不同PT含量时的介温谱、电滞回线和偏置电场诱导下的压电性能探讨了(1-x)PMN-xPT系统(x=0~0.4))的组成、结构与性能之间的关系.实验结果表明,当x<0.07时,PMN-PT材料表现为典型的弛豫铁电体;当0.07<x<0.13时,材料具有弛豫铁电体为主的过渡型结构;当0.13<x<0.33时,具有普通铁电体为主的过渡型结构;当x=0.33~0.34时,材料位于准同型相界,而当x>0.34,PMN-PT则表现为普通铁电体.

  19. EGF Receptor-Dependent Mechanism May be Involved in the Tamm–Horsfall Glycoprotein-Enhanced PMN Phagocytosis via Activating Rho Family and MAPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ko-Jen Li

    2014-01-01

    Full Text Available Our previous studies showed that urinary Tamm–Horsfall glycoprotein (THP potently enhanced polymorphonuclear neutrophil (PMN phagocytosis. However, the domain structure(s, signaling pathway and the intracellular events responsible for THP-enhanced PMN phagocytosis remain to be elucidated. THP was purified from normal human urine. The human promyelocytic leukemia cell line HL-60 was induced to differentiate into PMNs by all-trans retinoid acid. Pretreatment with different MAPK and PI3K inhibitors was used to delineate signaling pathways in THP-enhanced PMN phagocytosis. Phosphorylation of molecules responsible for PMN phagocytosis induced by bacterial lipopolysaccharide (LPS, THP, or human recombinant epidermal growth factor (EGF was evaluated by western blot. A p38 MAPK inhibitor, SB203580, effectively inhibited both spontaneous and LPS- and THP-induced PMN phagocytosis. Both THP and LPS enhanced the expression of the Rho family proteins Cdc42 and Rac that may lead to F-actin re-arrangement. Further studies suggested that THP and EGF enhance PMN and differentiated HL-60 cell phagocytosis in a similar pattern. Furthermore, the EGF receptor inhibitor GW2974 significantly suppressed THP- and EGF-enhanced PMN phagocytosis and p38 and ERK1/2 phosphorylation in differentiated HL-60 cells. We conclude that EGF receptor-dependent signaling may be involved in THP-enhanced PMN phagocytosis by activating Rho family and MAP kinase.

  20. PMN-PT/P(VDF-TrFE)复合材料的制备与电性能研究%Studies on preparation and electrical properties of PMN-PT/P(VDF-TrFE)composites

    Institute of Scientific and Technical Information of China (English)

    孟佳; 罗文博; 吴传贵; 孙翔宇; 张平; 俞玉澄; 帅垚

    2015-01-01

    Lead magnesium niobate-lead titanate (PMN-PT)ceramic prepared by columbite precursor method and polyvinylidene fluoride-trifluoroethylene P(VDF-TrFE)have been used to fabricate 0-3 composites thick films on ITO substrates by flow casting.The phase structure of PMN-PT was analyzed by XRD and the inter-face of 0-3 composites was characterized by SEM.Variation of dielectric constant (εr )and electric field applied to the ceramic phase (E c )with temperature were studied to optimize the polarization temperature.Further-more,compared with the conventional polarization in stages,PMN-PT ceramic content effect on pyroelectric properties of composites was also discussed under optimized polarization condition.The results showed that the pyroelectric coefficient increases to 58.6 μC/(m2 •K)at a ceramic mass fraction of 55% by polarizing tempera-ture with 1 10 ℃.%以铌铁矿预产物法合成的铌镁酸铅-钛酸铅(PMN-PT)陶瓷粉体和聚二氟乙烯-三氟乙烯共聚物 P (VDF-TrFE)为原料,采用流延法在 ITO 衬底上制备了不同质量配比的 PMN-PT/P (VDF-TrFE)复合厚膜.采用 XRD 及 SEM 分别分析了 PMN-PT 粉体的物相结构和复合材料的界面特征.通过测试复合材料的介电-温度曲线,计算出加载在陶瓷相上的极化分压与温度的关系,得到优化的极化温度.与常规的分步极化相比,探讨了在优化极化条件下陶瓷相含量对复合材料热释电性能的影响,结果表明在极化温度为110℃,PMN-PT 质量分数为55%时,得到了热释电系数为58.6μC/(m2•K)的热释电复合厚膜材料.

  1. The effect of two-step rapid thermal anneal on the structure and property of PMN-PT thin films%两步法快速退火对PMN-PT薄膜结构和性能的影响

    Institute of Scientific and Technical Information of China (English)

    郭红力; 刘果; 李雪冬; 肖定全; 朱建国

    2011-01-01

    采用射频磁控溅射法在LaNiO3(100)/SiO2/Si(100)衬底上制备了0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3(PMN-PT)铁电薄膜,采用两步法快速退火法对制备的PMN-0.35PT薄膜进行了不同工艺的后处理。实验结果表明,在LaNiO3上溅射的PMN-PT薄膜呈现高度的(100)取向。对PMN-PT薄膜测试表明,在合适的两步法快速退火处理时,可以获得表面平整颗粒饱满,且铁电性能很好的薄膜,其剩余极化强度(2Pr)可以达到24μC/cm2,平均粗糙度为7.4nm,在室温1%The 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3(PMN-PT) thin films was prepared on LaNiO3(100)/SiO2/Si(100) substrate via a RF magnetron sputtering method.The PMN-PT thin films were post-annealed by two-step rapid thermal anneal in different conditions.It was indicated that PMN-PT thin films show highly(100)-orientated.This surface of the thin films by proper two-step rapid thermal anneal was smooth,dense and crack-free,also show excellent ferroelectric properties.The(2Pr) can be up to 24μC/cm2,and the RMS roughness only 7.4nm.Furthermore,dielectric constant(εr) and loss(tanδ) are 545 and 0.062,respectively.

  2. PMN-PT陶瓷中的氧缺位及其消除%Oxygen Vacancies in PMN-PT Ceramics and Their Elimination

    Institute of Scientific and Technical Information of China (English)

    朱为民; 李承恩; 周家光; 李毅

    2002-01-01

    研究了组成中Pb含量的变化对组成为Pbx(Mg1/3Nb2/3)0.65Ti0.35O3的铌镁酸铅-钛酸铅(PMN(PT)陶瓷压电性能的影响,发现化学计量比组成(x=1)的Pbx(Mg1/3Nb2/3)0.65Ti0.35O3陶瓷经常出现压电性能的大幅度退化现象,而A位适量缺Pb能稳定地获得高性能的Pbx(Mg1/3Nb2/3)0.65Ti0.35O3陶瓷.XPS元素价态分析的结果表明,化学计量比的Pbx(Mg1/3Nb2/3)0.65Ti0.35O3陶瓷中含有较多的氧缺位,氧缺位的产生源于MgNb2O6(MN)合成过程中的气氛差异,A位适量缺Pb能有效地消除这种氧缺位而稳定地获得正常的压电性能,其机理被认为是氧缺位与铅缺位的复合.

  3. Effect of Weather on the Predicted PMN Landmine Chemical Signature for Kabul, Afghanistan

    Energy Technology Data Exchange (ETDEWEB)

    WEBB, STEPHEN W.; PHELAN, JAMES M.

    2002-11-01

    Buried landmines are often detected through the chemical signature in the air above the soil surface by mine detection dogs. Environmental processes play a significant role in the chemical signature available for detection. Due to the shallow burial depth of landmines, the weather influences the release of chemicals from the landmine, transport through the soil to the surface, and degradation processes in the soil. The effect of weather on the landmine chemical signature from a PMN landmine was evaluated with the T2TNT code for Kabul, Afghanistan. Results for TNT and DNT gas-phase and soil solid-phase concentrations are presented as a function of time of the day and time of the year.

  4. Design and Characterization of an Ultrasonic Surgical Tool Using d31 PMN-PT Plate

    Science.gov (United States)

    Kuang, Y.; Sadiq, M.; Cochran, S.; Huang, Z.

    An ultrasonic surgical tool for tissue incision and dissection has been designed and characterized. The surgical tool is based on a simple geometry to which PMN-PT d31 plates are bonded directly. The performance of the surgical tool has been defined numerically with the Abaqus finite element analysis (FEA) package and practically with laser vibrometer and impedance spectroscopy. The results show the ability of FEA to accurately predict the behaviors of an ultrasonic device as numerical and practical analysis were found to be in a good agreement. The design of the tool presented has the ability to generate displacement amplitude high enough to carry out soft tissue incision with relatively low driving voltage.

  5. PMN-PT single crystal focusing transducer fabricated using a mechanical dimpling technique.

    Science.gov (United States)

    Lam, K H; Chen, Y; Cheung, K F; Dai, J Y

    2012-01-01

    A ∼5MHz focusing PMN-PT single crystal ultrasound transducer has been fabricated utilizing a mechanical dimpling technique, where the dimpled crystal wafer was used as an active element of the focusing transducer. For the dimpled focusing transducer, the effective electromechanical coupling coefficient was enhanced significantly from 0.42 to 0.56. The dimpled transducer also yields a -6dB bandwidth of 63.5% which is almost double the bandwidth of the plane transducer. An insertion loss of the dimpled transducer (-18.1dB) is much lower than that of the plane transducer. Finite element simulation also reveals specific focused beam from concave crystal surface. These promising results show that the dimpling technique can be used to develop high-resolution focusing single crystal transducers.

  6. Electric field controlled magnetic hysteresis loops in a Metglas/PMN-PT heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yajie; Fitchorov, Trifon; Vittoria, Carmine; Harris, V G [Center for Microwave Magnetic Materials and Integrated Circuits, and the Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115 (United States); Cai, Zhuhua; Ziemer, K S, E-mail: y.chen@neu.ed [Department of Chemical Engineering, Northeastern University, Boston, MA 02115 (United States)

    2010-04-21

    An electric field tunable magnetic hysteresis loop was studied in a multiferroic heterostructure consisting of a 25 {mu}m thick Metglas (registered) ribbon affixed to a lead magnesium niobate-lead titanate (PMN-PT) crystal. This multiferroic heterostructure exhibits a considerably strong converse magnetoelectric effect, CME = -80%, where CME = [M(E) - M(0)]/M(0), and a converse magnetoelectric coupling constant, A = 23 Oe cm kV{sup -1}, in the vicinity of the saturation electric polarization. This work systematically demonstrates the tunability of magnetic parameters including magnetization, coercivity, remanence and squareness, under the application of an electric field of 0-8 kV cm{sup -1}. Additionally, the physical mechanism of the CME is discussed. These results provide useful resources for the design of a new generation of electrically controlled devices.

  7. High frequency PMN-PT single crystal focusing transducer fabricated by a mechanical dimpling technique.

    Science.gov (United States)

    Chen, Y; Lam, K H; Zhou, D; Cheng, W F; Dai, J Y; Luo, H S; Chan, H L W

    2013-02-01

    High frequency (∼30MHz and ∼80MHz) focusing ultrasound transducers were fabricated using a PMN-0.28PT single crystal by a mechanical dimpling technique. The dimpled single crystal was used as an active element for the focusing transducer. Compared with a plane transducer, the focusing transducer fabricated with a dimpled active element exhibits much broader bandwidth and higher sensitivity. Besides, a high quality image can be obtained by the 30MHz focusing transducer, in which the -6dB axial and lateral resolution is 27μm and 139μm, respectively. These results prove that the dimpling technique is capable to fabricate the high frequency focusing transducers with excellent performance for imaging applications.

  8. 弛豫铁电单晶PMN-PT的介电稳定性研究

    Institute of Scientific and Technical Information of China (English)

    李书相; 王丽坤; 秦雷; 许桂生

    2005-01-01

    实验研究了驰豫铁电单晶PMN-PT(67/33)分别在等静水压和定向应力的情况下,其介电性质的变化,分析了介电常数和介电损耗的变化趋势.结果表明,介电常数随静水压的增大缓慢增加,压力在10MPa内其相对变化小于2%,介质损耗均小于0.01;而在定向应力均匀增大的情况下,介电常数和介电损耗均出现峰值现象.

  9. Giant isothermal entropy change In (111)-oriented PMN-PT thin film

    Science.gov (United States)

    Hamad, Mahmoud A.

    2014-11-01

    An isothermal entropy change of 240 nm (111)-oriented PMN-PT 65/35 film near the ferroelectric Curie temperature, relative cooling power (RCP) and change of heat capacity have been investigated. The extracted data characterized giant isothermal entropy change of more than 16 J/kg K in electric field shift ΔE of 455 kV cm-1, which is nearly twice than that found for PbZr0.95Ti0.05O3 thin film at 492 kV cm-1 near the Curie point. Furthermore, the RCP ≈ 700 J/kg and change of heat capacity ≈ 233 J/kg K in electric field shift ΔE of 747 kV cm-1.

  10. Blocking force of a piezoelectric stack actuator made of single crystal layers (PMN-29PT)

    Science.gov (United States)

    Tran, K. S.; Phan, H. V.; Lee, H. Y.; Kim, Yongdae; Park, H. C.

    2016-09-01

    In this study, we fabricated and characterized a stack actuator made of forty layers of 1 mm thick PMN-29PT with a cross-sectional area of 10 × 10 mm2. From the measurement of actuation displacement, we confirmed that the piezoelectric strain constant in the direction of thickness of the material is 2000 pm V-1, as suggested by the manufacturer. The blocking forces of the actuator are measured to be 230 N, 369 N, and 478 N for 100 V, 200 V, and 300 V, respectively. The measured blocking forces showed large discrepancies from the estimated blocking forces calculated using linear models, especially for a high voltage application. An empirical equation acquired by fitting the measured blocking forces indicates that the blocking force has a nonlinear relationship with the applied voltage. The measured hysteresis showed a slight nonlinear voltage-stroke relationship and small energy loss.

  11. Field stability of piezoelectric shear properties in PIN-PMN-PT crystals under large drive field.

    Science.gov (United States)

    Zhang, Shujun; Li, Fei; Luo, Jun; Xia, Ru; Hackenberger, Wesley; Shrout, Thomas

    2011-02-01

    The coercive fields (E(C)) of Pb(In₀.₅Nb₀.₅)O₃-Pb(Mg(¹/₃)Nb(²/₃)O₃-PbTiO₃ (PIN-PMN-PT) ternary single crystals were found to be 5 kV/cm, double the value of binary Pb(Mg(¹/₃)Nb(²/₃)O₃-PbTiO₃ (PMNT) crystals, further increased to 6 to 9 kV/cm using Mn modifications. In addition to an increased EC, the acceptor modification resulted in the developed internal bias (E(int)), on the order of ~1 kV/cm. The piezoelectric shear properties of unmodified and Mn-modified PIN-PMN-PT crystals with various domain configurations were investigated. The shear piezoelectric coefficients and electromechanical coupling factors for different domain configurations were found to be >2000 pC/N and >0.85, respectively, with slightly reduced properties observed in Mn-modified tetragonal crystals. Fatigue/cycling tests performed on shearmode samples as a function of ac drive field level demonstrated that the allowable ac field levels (the maximum applied ac field before the occurrence of depolarization) were only ~2 kV/cm for unmodified crystals, less than half of their coercive field. Allowable ac drive levels were on the order of 4 to 6 kV/cm for Mn-modified crystals with rhombohedral/orthorhombic phase, further increased to 5 to 8 kV/cm in tetragonal crystals, because of their higher coercive fields. It is of particular interest that the allowable ac drive field level for Mn-modified crystals was found to be ≥ 60% of their coercive fields, because of the developed E(int), induced by the acceptor-oxygen vacancy defect dipoles.

  12. Measurements along the growth direction of PMN-PT crystals: dielectric, piezoelectric, and elastic properties.

    Science.gov (United States)

    Tian, Jian; Han, Pengdi; Payne, David A

    2007-09-01

    Property measurements are reported for Pb(Mg1/3Nb2/3)03-PbTiO3 (PMN-PT) single crystals grown along (001) by a seeded-melt method. Chemical segregation occurs during crystal growth, leading to property changes along the growth direction. Variations in dielectric, piezoelectric, and elastic properties were evaluated for specimens selected from the crystals. Room-temperature data are correlated with Tc and composition that ranged from 27 to 32% PT, i.e., in the vicinity of the morphotropic phase boundary (MPB). While there was little change in the high electromechanical coupling factor k33 (0.87-0.92), both the piezoelectric charge coefficient d33 (1100-1800 pC/N) and the free dielectric constant K3 (4400-7000) were found to vary significantly with position. Increases in d33 and KT33 were relatively offsetting in that the ratio yielded a relatively stable piezoelectric voltage coefficient g33 (27-31 x 10(-3) Vm/N). Values are also reported for the elastic compliance (3.3-6.3 x 10(-11) m2/N) determined from resonance measurements. Enhancements in d33 and K(T)33 were associated with lattice softening (increasing sE33) as the composition approached the MPB. Details are reported for the piezoelectric, dielectric, and elastic properties as a function of growth direction, Tc, and composition. The results are useful for an understanding of properties in PMN-PT crystals and for the design of piezoelectric devices.

  13. Microstructure and Properties of PMN-PT Ceramics Fabricated Using Molten Salts Method%熔盐法制备PMN-PT弛豫铁电陶瓷的显微结构及性能

    Institute of Scientific and Technical Information of China (English)

    赵世玺; 李强

    2005-01-01

    本文研究了熔盐法合成的PMN-PT粉末的烧结特性,以及合成工艺对PMN-PT陶瓷致密度,显微结构和介电性能的影响.结果显示,熔盐合成的粉料具有较小的颗粒尺寸和良好的分散性,能够降低陶瓷的烧结温度,在1150~1180℃范围烧结可得到致密度≥96%的PMN-PT陶瓷.在1100~1200℃烧结温度范围,硫酸盐熔盐体系制备的陶瓷呈沿晶断裂,而氯化物熔盐体系制备的陶瓷均呈穿晶断裂.在相同的烧结温度下,氯化物熔盐制备的陶瓷的晶粒尺寸明显大干硫酸盐熔盐体系的陶瓷的晶粒尺寸.用熔盐法制备的组分为0.67PMN-0.33PT陶瓷具有优良的压电和介电性能.在1175℃/2h烧结条件下,制备的0.67PMN-0.33PT陶瓷的最大介电常数为29385,d33 ≈ 660pC/N.

  14. Evidence of spin phonon coupling in magnetoelectric NiFe{sub 2}O{sub 4}/PMN-PT composite

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Anju; Satapathy, S., E-mail: srinu73@rrcat.gov.in, E-mail: srinusatapathy@gmail.com; Gupta, P. K. [Nano Functional Materials Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Sathe, V. G.; Choudhary, R. J. [UGC-DAE Consortium for Scientific Research, Indore 452017 (India)

    2013-12-16

    The coupling of phonon with spin in strain coupled magnetoelectric NiFe{sub 2}O{sub 4} (NFO)/0.65Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–0.35PbTiO{sub 3} (PMN-PT) composite was investigated by temperature-dependent Raman spectroscopy and magnetic measurements in the range 30–350 °C. Pure NFO shows usual ferromagnetic behaviour in this temperature range while NFO/PMN-PT composite show dramatic change in magnetic moment across ferroelectric transition temperature (T{sub c} ∼ 180 °C) of PMN-PT. The temperature evolution of the Raman spectra for the composite shows significant phonon anomalies in T-site (Fe-O) and O-site (Ni/Fe-O) phonon modes at ferroelectric transition temperature is attributed to spin phonon coupling in NFO/PMN-PT composite. The strain mediated magnetoelectric coupling mechanism in this composite is apparent from the observed spin phonon interaction.

  15. PPHASE AND MORPHOLOGY FORMATION OF Na DOPED PMN THIN FILMS PREPARED BY MODIFIED SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    HELENA BRUNCKOVÁ

    2013-03-01

    Full Text Available Na doped lead magnesium niobate Pb(Mg1/3Nb2/3O3 (Na-PMN thin films of 100 nm thickness were prepared by modified sol-gel route with niobium precursor. Na-PMN films were deposited from sol derived using tartaric acid modified polymerizable complex method by mixing of Nb-tartarate (Pechini complex with Na, Pb and Mg acetates at 80°C with molar ratio of Na : Pb : Mg : Nb = 1/2 : 1 :1/3 : 2/3 on Pt/Al2O3 substrates by spin-coating method. In Na doped PMN film the perovskite Pb(Mg1/3Nb2/3O3 phase (65 vol. % and a small amount of pyrochlore Na2Nb8O21 phase were revealed after sintering at 650°C. In the microstructure of 2-layered Na-PMN/Pt/Al2O3 thin film, with ~9.5 nm of roughness, the bimodal particle distribution was observed with small spherical particles of pyrochlore phase and larger sponge-like particles of the perovskite phase. The smallest visible spherical particles (~30 nm and mutually interconected particles (~125 nm were found in TEM and AFM micrographs.

  16. Greater migratory propensity in hosts lowers pathogen transmission and impacts.

    Science.gov (United States)

    Hall, Richard J; Altizer, Sonia; Bartel, Rebecca A

    2014-09-01

    Animal migrations are spectacular and migratory species have been shown to transmit pathogens that pose risks to human health. Although migration is commonly assumed to enhance pathogen dispersal, empirical work indicates that migration can often have the opposite effect of lowering disease risk. Key to assessing disease threats to migratory species is the ability to predict how migratory behaviour influences pathogen invasion success and impacts on migratory hosts, thus motivating a mechanistic understanding of migratory host-pathogen interactions. Here, we develop a quantitative framework to examine pathogen transmission in animals that undergo two-way directed migrations between wintering and breeding grounds annually. Using the case of a pathogen transmitted during the host's breeding season, we show that a more extreme migratory strategy (defined by the time spent away from the breeding site and the total distance migrated) lowers the probability of pathogen invasion. Moreover, if migration substantially lowers the survival probability of infected animals, then populations that spend comparatively less time at the breeding site or that migrate longer distances are less vulnerable to pathogen-induced population declines. These findings provide theoretical support for two non-exclusive mechanisms proposed to explain how seasonal migration can lower infection risk: (i) escape from habitats where parasite transmission stages have accumulated and (ii) selective removal of infected hosts during strenuous journeys. Our work further suggests that barriers to long-distance movement could increase pathogen prevalence for vulnerable species, an effect already seen in some animal species undergoing anthropogenically induced migratory shifts.

  17. Development of migratory behavior in northern white-tailed deer

    Science.gov (United States)

    Nelson, M.E.

    1998-01-01

    I examined the development of migratory behavior in northern white-tailed deer (Odocoileus virginianus) from 1975 to 1996 by radio-tracking adult females and their fawns. Of 40 migratory fawns with radio-collared mothers, all returned from winter ranges to their mothers' summer ranges, as did 36 fawns with unknown mothers. Of 1.5- to 3.0-year-old daughters with radio-collared mothers, 67-80% continued migrating with mothers to their traditional summer ranges. Eighty-four percent (16/19) of yearling dispersers continued migratory behavior after replacing their natal summer ranges with their dispersal ranges, and 88% (14/16) of these continued migrating to their natal winter ranges, some through at least 6.5 years of age. Twenty percent (4/20) of nonmigratory fawns dispersed as yearlings, and two became migratory between their dispersal summer ranges and new winter ranges, one through 4.9 years of age and another through 6.5 years. Seven fawns changed their movement behavior from migratory to nonmigratory or vice versa as yearlings or when older, indicating that migratory behavior is not under rigid genetic control. Thus, the adaptiveness of migration must depend upon natural selection operating upon varying capacities and propensities to learn and mimic long-distance movements and not upon migratory behavior directly.

  18. Migratory Prostitution with Emphasis on Europe.

    Science.gov (United States)

    M&oring;rdh; Genç

    1995-03-01

    In many European countries, foreigners constitute the majority of certain groups of prostitutes, e.g., approximately 90% of the window prostitutes in the red light district of Amsterdam are not native to the Netherlands. The same is true for prostitutes working in bars in Vienna. In cities where registered prostitution is legal, unregistered prostitutes, most of whom are foreigners, often outnumber the registered ones. Central European countries often receive "sex workers" from eastern Europe, e.g., from Bulgaria, the Czech Republic, Slovakia, Hungary, and Romania, whereas the majority of migratory prostitutes in Great Britain and continental western Europe come from Africa, the Caribbean, and South America. In northern Europe, women from Russia, the Czech Republic, Slovakia, Poland, and the Baltic states are prostituting themselves in increasing numbers. Scandinavia has so far been affected relatively less by this mobility. In Spain, France, and Italy, women from Arabic and subSaharan countries are common among prostitutes. Foreign prostitutes move into Turkey along two main routes: women from the Balkan countries come to the western part of the country, whereas those from the former Soviet Union cross the border from Georgia, where they usually operate at resorts along the eastern Black Sea coast. Prostitutes are also mobile within the former communist bloc. For instance, women from Russia prostitute themselves in Lithuania, the Czech Republic, Slovakia, and Hungary. the customers are locals, particularly those with "hard currency", such as businessmen and "sex tourists" from the West. Following the outbreak of civil war in the former Yugoslavia, women from that country are now more frequently seen among the population of migratory prostitutes in Europe.

  19. Magnetoelectric coupling in multiferroic heterostructure of rf-sputtered Ni-Mn-Ga thin film on PMN-PT

    Energy Technology Data Exchange (ETDEWEB)

    Teferi, M.Y., E-mail: mandefero2002@yahoo.com [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Amaral, V.S.; Lounrenco, A.C.; Das, S. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Amaral, J.S. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); IFIMUP-IN and Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, 4169-007 Porto (Portugal); Karpinsky, D.V. [CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Departamento de Engenharia Ceramica e do Vidro, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Soares, N. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Sobolev, N.A. [Departamento de Fisica, Universidade de Aveiro, 3810-193 Aveiro (Portugal); I3N, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Kholkin, A.L. [CICECO, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Departamento de Engenharia Ceramica e do Vidro, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Tavares, P.B. [Centro de Quimica, Universidade de Tras-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal)

    2012-06-15

    In this paper, we report a preparation of multiferroic heterostructure from thin film of Ni-Mn-Ga (NMG) alloy and lead magnesium niobate-lead titanate (PMN-PT) with effective magnetoelectric (ME) coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material. The heterostructure was prepared by relatively low temperature (400 Degree-Sign C) deposition of the film on single crystal of piezoelectric PMN-PT substrate using rf magnetron co-sputtering of Ni{sub 50}Mn{sub 50} and Ni{sub 50}Ga{sub 50} targets. Magnetic measurements by Superconducting Quantum Interference Design (SQIUD) Magnetometer and Vibrating Sample Magnetometer (VSM) on the film revealed that the film is in ferromagnetically ordered martensitic state at room temperature with saturation magnetization of {approx}240 emu/cm{sup 3} and Curie temperature of {approx}337 K. Piezoresponse force microscopy (PFM) measurement done at room temperature on the substrate showed the presence of expected hysteresis loop confirming the stability of the piezoelectric state of the substrate after deposition. Room temperature ME voltage coefficient ({alpha}{sub ME}) of the heterostructure was measured as a function of applied bias dc magnetic field in Longitudinal-Transverse (L-T) ME coupling mode by lock-in technique. A maximum ME coefficient {alpha}{sub ME} of 3.02 mV/cm Oe was measured for multiferroic NMG/PMN-PT heterostructure which demonstrates that there is ME coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material. - Highlights: Black-Right-Pointing-Pointer Multiferroic NMG/PMN-PT heterostructure prepared by depositing NMG alloy thin film on PMN-PT substrate. Black-Right-Pointing-Pointer The film is in ferromagnetically ordered martensite state at room temperature. Black-Right-Pointing-Pointer The substrate maintains its piezoelectric state after deposition. Black-Right-Pointing-Pointer The heterostructure exhibits ME effect with maximum of {alpha}{sub ME

  20. 50 CFR 20.25 - Wanton waste of migratory game birds.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Wanton waste of migratory game birds. 20... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.25 Wanton waste of migratory game birds. No person shall kill or cripple any migratory game bird pursuant to this part...

  1. 76 FR 39367 - Migratory Bird Permits; Changes in the Regulations Governing Raptor Propagation

    Science.gov (United States)

    2011-07-06

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX78 Migratory Bird Permits; Changes in the... primary responsibility for managing migratory birds. Our authority is based on the Migratory Bird Treaty... take and possession of migratory birds for many purposes. The BGEPA allows bald eagles and...

  2. Migratory Homes: Redesigning Group Identity, Prototyping Social Change

    Directory of Open Access Journals (Sweden)

    Traganou, Jilly

    2011-07-01

    Full Text Available This paper describes Migratory Homes, two collaborative projects that investigate the notion of home/land and belonging in conditions of displacement. The fundamental question that Migratory Homes asks is “how can the disparate identities that constitute mixed societies collectively and equally participate in the creation of a common ‘home/land’ that would be co-designed, co-produced, and co-owned”? Through iterative engagements with conditions of everyday materiality, and by activating processes of co-design as research, Migratory Homes attempt to prototype conditions for social change.

  3. 两步无机盐-凝胶法制备PMN-PT弛豫铁电陶瓷粉体

    Institute of Scientific and Technical Information of China (English)

    陈晋; 樊慧庆; 邱少君; 王志银

    2007-01-01

    0.65Pb(Mg1/3Nb2/3)O3—0.35PbTiO3(简称:PMN-PT)弛豫铁电粉体采用两步无机盐-凝胶法制备。以氧化镁,醋酸铅,钛酸丁脂为原料,柠檬酸为螫合剂,乙二醇为溶剂,分别合成稳定的Mg,Pb-Ti的有机化合物先驱体溶液。Nb2O5粉体与Mg先驱体溶液均匀混合,并采用溶胶-凝胶工艺制备MgNb2O6(MN)先驱体粉体;MN粉体与Pb-Ti先驱体溶液均匀混合,并制备PMN-PT粉体。通过XRD和SEM分析PMN-PT钙钛矿相形成的影响因素和微观形貌,研究全钙钛矿相PMN-PT铁电粉体的制备。结果表明:过量3%MgO前驱体经1050℃,4h煅烧可以得到纯相MgNb2O6先驱体粉体:过量5%PbO前驱体经900℃,4h煅烧可以得到全钙钛矿相PMN-PT粉体。

  4. 准同型相界附近PMN-PT材料的制备和性能%Preparation and Property of PMN-PT Material near the Morphotropic Phase Boundary

    Institute of Scientific and Technical Information of China (English)

    孙大志

    2001-01-01

    对铁电菱方(FR)-铁电四方(FT)准同型相界附近的铌镁酸铅(PMN)-钛酸铅(PT)材料制备方法和介电、压电和热释电性能进行了系统的研究: 在合成(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3时,易出现烧绿石相。由于MgO的化学活性低,而PbO和Nb2O5的反应活性大大高于MgO,因此在一次性合成PMN-PT材料过程中会形成烧绿石相,得不到纯钙钛矿相,并且导致材料性能下降。本工作采用二步合成法避免了烧绿石相形成,获得了纯钙钛矿相的PMN-PT粉体。在极端条件下,将原料MgO、Nb2O5、PbO和TiO2一起熔融,经过一定时间的扩散反应,通过一步反应即可以得到纯钙钛矿结构的PMN-PT材料,证明钙钛矿结构事实上是一种具有低自由能的稳定态。 PMN-PT系统存在着一条铁电菱方-铁电四方准同型相界,它的化学组成在PT含量为33%附近。在准同型相界附近,PMN-PT陶瓷材料具有较好的压电性能,d33可达540 pC/N,kt、kp分别可达0.45和0.62;在准同型相界附近,极化后的(1-x)PMN-xPT陶瓷材料(0.22 < x < 0.35)的介电常数在温度诱导FR-FT相变过程中发生突变;PMN-PT陶瓷材料在FR-FT相变过程中呈现出一个热释电峰,反应了自发极化在相变过程中发生了非线性的变化。PMN-PT陶瓷材料在FR-FT相变过程中的热释电效应可以用一个半经验公式,即自然指数的负二次幂函数来进行描述。这种半定量关系的建立为进一步深入研究FR-FT相变的微观机理建立了实验基础。 采用Bridgman方法可以大批量生长高性能、大尺寸的PMN-PT单晶。PMN-PT单晶的压电系数d33可达2 300 pC/N以上,kt可达0.59,远高于同组分的陶瓷材料;PMN-PT单晶的压电性能具有明显的各向异性。(001)切型样品的d33达2 300 pC/N,而(110)切型的样品仅为其50%左右,(111)切型的样品则只有200 pC/N不到;由于PbO、Nb2O5、TiO2

  5. Bear River Migratory Bird Refuge [Land Status Map

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Bear River Migratory Bird Refuge. It was generated from rectified aerial photography,...

  6. Monthly Report (April): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  7. Monthly Report (January): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  8. Monthly Report (September): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North...

  9. Sod house news [Malheur Migratory Bird Refuge, July 1938

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is report written by the CCC personnel about the Sod House Camp on Malheur Migratory Bird Refuge. Topics covered include sports, technical services, camp...

  10. Bear River Migratory Bird Refuge: Annual narrative report: 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1994 calendar year. The report begins with a summary of...

  11. Monthly Report (February): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  12. Annual Report: Lower Souris Migratory Waterfowl Refuge: Fiscal Year 1938

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  13. Monthly Report: April 1936: Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  14. Monthly Report (June): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  15. [Wildlife Inventory Plan : Bear River Migratory Bird Refuge : 1966

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This inventory plan for the Bear River Migratory Bird Refuge includes a summary of refuge objectives, an explanation of the policy on wildlife inventory procedures,...

  16. Monthly Report (July): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  17. Monthly Report (September): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  18. Monthly Report (May): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  19. Migratory Bird Disease Contingency Plan: Back Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Back Bay National Wildlife Refuge was established in 1938 to provide habitat and protection for migratory birds. Management objectives have since been expanded to...

  20. Monthly Report (January): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North...

  1. Chautauqua National Wildlife Refuge : Migratory Bird Disease Contingency Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Disease Contingency Plan for Chautauqua National Wildlife Refuge provides background information on migratory bird disease surveillance; an inventory of Refuge...

  2. [Narrative report : Pea Island Migratory Wildfowl Refuge : Year 1941

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This 1941 narrative report for Pea Island Migratory Wildfowl Refuge lists wildlife observed on the refuge and compares it with 1940 data. Water conditions,...

  3. Waterfowl spring migration records on the Seney Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to compare the numbers of migratory waterfowl using the Seney Refuge area during the spring of 1937 with the numbers recorded during...

  4. Monthly Report (February): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  5. Monthly Report (December): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  6. Monthly Report (August): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  7. Monthly Report (May): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  8. Monthly Report (October): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  9. Sand Lake Migratory Waterfowl Refuge : Monthly report : March, 1938

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report describes activities on Sand Lake Migratory Waterfowl Refuge during March of 1938. Weather conditions, waterfowl, upland game, fur and predator control,...

  10. [Bear River Migratory Bird Refuge Hunt Plan & Related Documents : 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 'Bear River Migratory Bird Refuge Hunt Plan', beginning on page 66 and continuing through the end of the document, is focused on public hunting and the...

  11. Migratory Bird Disease Contingency Plan : Mingo National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Migratory Bird Disease Contingency Plan for Mingo NWR provides background information on disease surveillance; an inventory of Refuge personnel, equipment, and...

  12. Annual report : 1938-1939 : Sand Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sand Lake Migratory Waterfowl Refuge covers the 1939 fiscal year. Wildlife populations, artificial islands, haying, share cropping,...

  13. Bear River Migratory Bird Refuge: Comprehensive Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Bear River Migratory Bird Refuge for the next 15 years. This plan outlines the Refuge...

  14. Monthly Report (June): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  15. Monthly Report (April): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  16. Monthly Report (August): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  17. Bear River Migratory Bird Refuge : Summary of biological data 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of biological data collected at Bear River Migratory Bird Refuge for the year 1992. Data is summarized in tables, charts, graphs and written summaries. Data...

  18. Management of grasslands 1996 : Bear River Migratory Bird Refuge [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a summary of grassland management for Bear River Migratory Bird Refuge in Utah, which has recently began acquiring new grassland habitat that will...

  19. Bear River Migratory Bird Refuge : Summary of biological data 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of biological data collected at Bear River Migratory Bird Refuge for the year 1994. Data is summarized in tables, charts, graphs and written summaries....

  20. [Sand Lake Migratory Waterfowl Refuge : Narrative report : 1935

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report covers activities on Sand Lake Migratory Waterfowl Refuge during 1935. The road construction, dam construction, food and cover,...

  1. Monthly Report (July): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  2. Bear River Migratory Bird Refuge: Narrative report: 1973

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1973 calendar year. The report begins by summarizing the...

  3. Environmental Assessment : Bear River Migratory Bird Refuge Hunt Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment (EA) is designed to evaluate possible actions for modifying the Bear River Migratory Bird Refuge (Refuge) public hunt plan. The hunt...

  4. Bear River Migratory Bird Refuge: Annual narrative report: 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1993 calendar year. The report begins with a summary of...

  5. Narrative report : Pea Island Migratory Wildfowl Refuge : Year 1940

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This 1940 narrative report for Pea Island Migratory Wildfowl Refuge provides a roster of army personnel and service personnel, a summary of education, information...

  6. Monthly Report (September): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  7. Annual report : 1936-'37 : Sand Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report covers activities on Sand Lake Migratory Waterfowl Refuge during the 1937 fiscal year. Weather conditions, water levels, wildlife,...

  8. Bear River Migratory Bird Refuge: Annual narrative report: 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1995 calendar year. The report begins with a summary of...

  9. Monthly Report (October): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  10. Crescent Lake Migratory Bird Refuge First quarter, fiscal year 1932

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report summarizes wildlife, grazing, protection, improvements, developments, public relations, and disease on Crescent Lake Migratory Bird Refuge...

  11. Monthly Report (March): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  12. Demography of migratory vultures in and around Jodhpur, India

    African Journals Online (AJOL)

    2008-03-18

    Mar 18, 2008 ... Location of roosting, feeding and drinking sites of migratory vultures in and around Jodhpur, Western India. ... seasonal movements, and behaviour in and around Jodhpur .... Although predation of large raptors by predators is ...

  13. Monthly Report: November 1935: Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  14. Monthly Report (November): Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  15. Narrative report: July, 1937: Medicine Lake Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This monthly narrative report for Medicine Lake NWR summarizes weather conditions, water conditions, field crops, grazing, haying, visitors, flood damage, migratory...

  16. PMN-PT piezoelectric-electrostrictive bi-layer composite actuators

    Science.gov (United States)

    Ngernchuklin, Piyalak

    In the past few decades, significant advances have been achieved to replace the conventional actuators, including hydraulic, shape memory alloy, electromagnetic and linear induction, with piezoelectric actuators since they are light weight and small in size, have precision positioning capabilities, offer a wide range of generative force, consume less power, and provide higher durability and reliability. The strain produced by bulk polycrystalline piezoelectric ceramics and single crystals are typically in the range of 0.1 to 1%, respectively, which is still low for many applications. Therefore, various strain amplification designs including multilayer, bimorph, unimorph, flextensional actuators (Moonie and cymbal), co-fired and functionally graded ceramics have been proposed to enhance the displacement. In this investigation, Piezoelectric/Electrostrictive Bi-Layer Monolithic Composites (PE-MBLC) were fabricated by co-pressing and co-sintering of the piezoelectric (PMN-PT 65/35: P) and electrostrictive (PMN/PT 90/10: E) powders. Flat and dome shaped of PE-MBLCs were obtained by optimizing processing conditions such as pressing pressure and sintering temperature. In addition, poling conditions of bilayer composite actuators were thoroughly studied to maximize their electromechanical properties. It was found that composites had lower d33eff and Keff values than the calculated values. This was attributed to a significant difference between relative permittivities of P and E materials as well as the presence of induced stresses in both P and E layers after sintering that hindered domain switching within piezoelectric layer during poling. The shape change (planar to dome), electromechanical properties, and actuation performance of PE-MBLC actuators were examined as a function of volume percent of piezoelectric phase. The highest displacement ˜15 mum was obtained from PE-MBLC actuator with 50 volume % piezoelectric phase due to the transverse strain response of

  17. Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors

    Science.gov (United States)

    Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

    2007-01-01

    There has been a growing interest in recent years in lead based perovskite ferroelectric and relaxor ferroelectric solid solutions because of their excellent dielectric, piezoelectric and electrostrictive properties that make them very attractive for various sensing, actuating and structural health monitoring (SHM) applications. We are interested in the development of highly sensitive and efficient PMN-PT sensors based on large single crystals for the structural health monitoring of composite materials that may be used in future spacecrafts. Highly sensitive sensors are needed for detection of defects in these materials because they often tend to fail by distributed and interacting damage modes and much of the damage occurs beneath the top surface of the laminate and not detectable by visual inspection. Research is being carried out for various combinations of solid solutions for PMN-PT piezoelectric materials and bigger size crystals are being sought for improved sensor applications. Single crystals of this material are of interest for sensor applications because of their high piezoelectric coefficient (d33 greater than 1700 pC/N) and electromechanical coefficients (k33 greater than 0.90). For comparison, the commonly used piezoelectric ceramic lead zirconate titanate (PZT) has a d33 of about 600 pC/N and electromechanical coefficients k33 of about 0.75. At the present time, these piezoelectric relaxor crystals are grown by high temperature flux growth method and the size of these crystals are rather small (3x4x5 mm(exp 3). In the present paper, we have attempted to grow bulk single crystals of PMN-PT in a 2 inch diameter platinum crucible and successfully grown a large size crystal of 67%PMN-33%PT using the vertical gradient freeze technique with no flux. Piezoelectric properties of the grown crystals are investigated. PMN-PT plates show excellent piezoelectric properties. Samples were poled under an applied electric field of 5 kV/cm. Dielectric properties at a

  18. (1-x)PMN-xPT陶瓷电致应变及其温度稳定性的研究%Temperature-stable electrostrictive strain for (1-x)PMN-xPT

    Institute of Scientific and Technical Information of China (English)

    杨祖培; 方秋霞; 崔斌; 屈绍波; 田长生

    2000-01-01

    采用NaCl-KCl熔盐法制备了纯钙钛矿相结构的(1-x)PMN-xPT陶瓷,研究了他们的电致应变及其温度稳定性.结果表明,随着PT含量的增加,PMN基陶瓷的最大电致应变逐渐增大,且具有较大的电致应变,最大应变达0.1%以上,但(1-x)PMN-xPT陶瓷的电致应变温度稳定性很差,其最大TSmax比Tm约低20℃.

  19. Piezoresponse force microscopy studies of domain structures in relaxor-type PMN-PT single crystals%PMN-PT弛豫铁电单晶畴结构的压电响应力显微术研究

    Institute of Scientific and Technical Information of China (English)

    曾华荣; 余寒峰; 初瑞清; 李国荣; 罗豪; 殷庆瑞

    2004-01-01

    利用压电响应力显微术开展了PMN-PT弛豫铁电单晶铁电畴结构的三维极化取向成像、畴结构的不均匀性及极化状态稳定性机理的研究.揭示了纳米尺度畴结构的不均匀性源于纳米尺度极性微区的相互作用和无规场之间的共同调制,而单晶表面屏蔽电荷机制主要源于大气环境下水的溶解性吸附,该机制对PMN-PT单晶中畴状态的稳定性及材料最佳性能的发挥起着重要作用.

  20. PREPARATION AND CHARACTERIZATION OF PMN-PT RELAXATION FERROELECTRIC POWDER BY COLUMBITE PRECURSOR METHOD%先驱体合成法制备PMN-PT弛豫铁电体及其表征

    Institute of Scientific and Technical Information of China (English)

    邓金侠; 邢献然; 于然波; 陈骏; 邢奇凤; 罗君; 刘桂荣

    2005-01-01

    采用先驱体合成法,以氧化物为原料制备了钙钛矿结构的(1-x)PMN-xPT弛豫铁电陶瓷粉末,研究了预烧温度以及PbTiO3固溶量等工艺参数对样品的相结构的影响.结果表明,随预烧温度升高,PMN-PT钙钛矿相含量增加,但温度过高,由于PbO的挥发钙钛矿相又减少;增加PbTiO3也可使钙钛矿相含量增加.

  1. 前驱物性质对PMN-PT弛豫铁电薄膜制备的影响%Influence of Properties of the precursor on the Formation of PMN-PT Relaxor Ferroelectric Thin Films

    Institute of Scientific and Technical Information of China (English)

    王歆; 庄志强; 陆裕东

    2005-01-01

    以无机盐为原料,柠檬酸和EDTA为复合螯合剂,乙二醇为溶剂制备PMN-PT弛豫铁电薄膜,研究了复合金属有机盐前驱物的性质对薄膜结构和成膜质量的影响.结果表明:成膜的前驱物最佳浓度为0.35~0.40 mol/L;苯甲酸添加剂参与溶胶的聚合,有利于钙钛矿结构相的形成.获得了均匀连续的近全钙钛矿结构相(≥99%)PMN-PT弛豫铁电薄膜.

  2. PREPARATION OF PMN-PT RELAXOR FEROELECTRIC POWDERS AND FILMS BY A SOLUBLE-INORGANIC SALT-GEL METHOD%PMN-PT弛豫铁电粉体和薄膜的无机盐-凝胶法制备

    Institute of Scientific and Technical Information of China (English)

    王歆; 庄志强

    2002-01-01

    以无机盐为原材料、柠檬酸和EDTA为复合螯合剂, 乙二醇为溶剂, 合成稳定和均匀的Pb-Mg-Nb-Ti的复合有机盐前驱溶液;通过TGA, DTA和XRD等方法分析复合有机盐前驱物凝胶的热解过程和PMN-PT钙钛矿相形成的影响因素, 研究近全钙钛矿相铌镁酸铅-钛酸铅(PMN-PT)弛豫铁电粉体和薄膜的制备.

  3. Comparison of Navigation-Related Brain Regions in Migratory versus Non-Migratory Noctuid Moths

    Directory of Open Access Journals (Sweden)

    Liv de Vries

    2017-09-01

    Full Text Available Brain structure and function are tightly correlated across all animals. While these relations are ultimately manifestations of differently wired neurons, many changes in neural circuit architecture lead to larger-scale alterations visible already at the level of brain regions. Locating such differences has served as a beacon for identifying brain areas that are strongly associated with the ecological needs of a species—thus guiding the way towards more detailed investigations of how brains underlie species-specific behaviors. Particularly in relation to sensory requirements, volume-differences in neural tissue between closely related species reflect evolutionary investments that correspond to sensory abilities. Likewise, memory-demands imposed by lifestyle have revealed similar adaptations in regions associated with learning. Whether this is also the case for species that differ in their navigational strategy is currently unknown. While the brain regions associated with navigational control in insects have been identified (central complex (CX, lateral complex (LX and anterior optic tubercles (AOTU, it remains unknown in what way evolutionary investments have been made to accommodate particularly demanding navigational strategies. We have thus generated average-shape atlases of navigation-related brain regions of a migratory and a non-migratory noctuid moth and used volumetric analysis to identify differences. We further compared the results to identical data from Monarch butterflies. Whereas we found differences in the size of the nodular unit of the AOTU, the LX and the protocerebral bridge (PB between the two moths, these did not unambiguously reflect migratory behavior across all three species. We conclude that navigational strategy, at least in the case of long-distance migration in lepidopteran insects, is not easily deductible from overall neuropil anatomy. This suggests that the adaptations needed to ensure successful migratory behavior

  4. 应用于非制冷焦平面器件上的PMN-PT铁电薄膜%PMN-PT Thin Film for Uncooled Infrared Focal Plane Array Applications

    Institute of Scientific and Technical Information of China (English)

    李振豪; 李琳; 普朝光

    2011-01-01

    利用射频磁控溅射方法生长掺钛铌镁酸铅-钛酸铅(lead magnesio-niobate titanate,PMN-PT)薄膜,研究PMN-PT薄膜的热处理技术,并测试制备的PMN-PT薄膜样品的晶向结构及电性能。结果表明:PMN-PT薄膜在450℃退火就能完全晶化成钙钛矿结构,其热释电系数达到0.9×10-8C/(cm2K),有望解决目前阻碍集成式铁电型非制冷焦平面探测器技术发展的瓶颈问题,即铁电薄膜晶化生长所需的高温与读出电路可承受温度的兼容性问题。%lead magnesio–niobate titanate(PMN–PT) ferroelectric thin films were prepared by radio-frequency magnetron sputtering.An annealing procedure for PMN–PT thin films with pre-annealing process was studied.After the annealing procedure was applied,performances of the thin films were investigated.Experimental results show that pre-annealing at 300 ℃ for 5 min followed by an-nealing at 450 ℃ for 5 min are enough for the perovskite formation of PMN–PT films.The test of samples performance with py-roelectric coefficients of 0.9 × 10–8 C/(cm2?K) for PMN–PT thin films indicates that the low annealing procedure might play an im-portant role in the development of monolithic ferroelectric uncooled focal plane arrays.

  5. Orientation of migratory birds under ultraviolet light.

    Science.gov (United States)

    Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2014-05-01

    In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m(2), birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m(2), robins showed an axial preference in the east-west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m(2), robins changed direction to a north-south axis. When UV light was combined with yellow light, robins showed easterly 'fixed direction' responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other.

  6. PMN-PT弛豫铁电陶瓷的低温烧结与压电性能%Research on Low Temperature Sintering and Piezoelectric Properties of PMN-PT Relaxor Ferroelectric Ceramics

    Institute of Scientific and Technical Information of China (English)

    曹林洪; 姚熹; 徐卓

    2005-01-01

    以LiF为烧结助剂研究了PMN-PT 68/32弛豫铁电陶瓷的低温烧结和压电性能.结果表明:LiF烧结助剂完全固溶到PMN-PT陶瓷中形成具有复合钙钛矿结构的固溶体,无任何第二相存在.添加2.5%LiF烧结助剂可以使PMN-PT压电陶瓷的烧结温度从1250℃降到1000℃,而且该试样具有致密均匀的显微结构,其体积密度为7.87g/cm3,达理论密度的95%,其平面机电耦合系数为71%,压电常数为500pC/N左右,最大应变量达0.25%左右.

  7. Dielectric relaxation properties of PMN-PT single crystals under hydrostatic pressure%等静压力诱导的PMN-PT单晶介电弛豫特性研究

    Institute of Scientific and Technical Information of China (English)

    戴中华; 邢普; 姚熹; 徐卓

    2009-01-01

    研究了不同等静压力下的PMN-PT单晶的介电常数(εr)与温度(T)的关系,以及常温下介电常数(εr)及损耗(tanδ)与压力(p)之间的关系.发现了PMN-PT单晶在压力作用下出现明显的介电频率弥散现象.当等静压力增大到一定压力时,PMN-PT单晶的介电常数值迅速降低,介电频率弥散更加显著,且出现弛豫特性,介电损耗的弛豫特征更加明显.随着频率的增加,介电损耗峰对应的峰值压力向高压方向移动.其根本原因是压力诱导的介电-压力弛豫特性导致的.

  8. PMN-PT层/弹性基底结构中声表面波特性分析%REVIEW SUGGESTION TO TECHNICAL PAPER SURFACE ACOUSTIC WAVE PROPAGATION IN THE PMN-PT lAYER/ELASTIC SUBSTRATE

    Institute of Scientific and Technical Information of China (English)

    孔艳平; 刘金喜

    2015-01-01

    研究了PMN-PT压电层/弹性(金刚石)基底结构中表面波的传播特性,压电层表面是机械自由的,电学边界条件分为电学开路和电学短路,压电层与基底之间采用理想连接.得到了满足控制方程和边界条件的电弹场以及弹性波在结构中传播时的频散方程,通过数值算例分析了压电材料PMN-PT的极化方向对弹性波频散曲线和机电耦合系数的影响,以及不同极化方向时弹性位移和电势随结构深度方向的变化,结果可为PMN-PT压电材料在高频声表面波器件中的应用提供有价值的理论参考.

  9. Ferroelectric phase transition in relaxor ferroelectric single crystals 0.76PMN-0.24PT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The features of the single crystals 0.76PMN-0.24PT in dielectric, ferroelectric, pyroelectric properties and domain structures indicate that they are located between typical ferroelectrics and normal ones. The unpoled crystals present a transitional domain configuration between microdomains and typical macrodomains while the crystals on (001) cuts undergo field-induced phase transition under poling, showing two special temperature points Td and Tm during the succedent heating procedure. The dielectric constant starts to decrease drastically at Td during cooling, or the transformation from induced macrodomain to transitional domain takes place at Td during heating. Ferroelectric-paraelectric phase transition or depolarization continues within the whole temperature range of Td-Tm, where ferroelectric phase in the form of transitional macrodomains coexists with paraelectric phase. Then the crystals macroscopically transoform into paraelectric phase containing ferroelectric microdomains at a temperature above Tm. However, owing to the influence of crystallite orientation on field-induced phase transition, the temperature Td does not appear in the same temperature-electric field history in multicrystal ceramics with the same composition as the above single crystals.

  10. Application of a Preisach Hysteresis Model to the Evaluation of PMN-PT Ceramics Properties

    Directory of Open Access Journals (Sweden)

    Wawrzała P.

    2013-12-01

    Full Text Available Praca przedstawia rozszerzoną, relatywnie nową, iteracyjną metodę uzyskiwania klasycznego rozkładu Preisacha z po- jedynczej, nasyconej pętli histerezy. Jako materiał do badań i analizy wybrano ceramiczny roztwór stały (1-xPb(Mg1/3Nb2/3O3-xPbTiO3 (x = 0 do 0.40. Uzyskano matry ce rozkładów Preisacha dla ceramik (l-.tPMN-.rPT w funkcji zawartości PT oraz w funkcji temperatury dla wybranego składu z obszaru morfotropowego. Ponadto, zaproponowano matematyczny model dla dystrybucji Preisacha i wyznaczono parametry rozkładu. Porównano typowe współczynniki możliwe do uzyskania bezpośrednio z pętli histerezy z współczynnikami wynikającymi z analitycznego modelu Preisacha.

  11. PMN-PT单晶铁电畴的扫描探针显微术

    Institute of Scientific and Technical Information of China (English)

    刘黎明; 曾华荣; 李国荣; 罗豪甦; 殷庆瑞

    2010-01-01

    利用在商用原子力显微镜基础上自行建立的压电响应力显微术(PFM)和低频扫描探针声学显微术(LF-SPAM)系统地开展了PMN—PT弛豫铁电单晶铁电畴结构的高分辨率成像研究。成功地观察到了准同型相界附近不同组成的PMN-PT弛豫铁电单晶精细的纳米铁电畴构型。首次获得了内应力诱导的“W”形状电畴结构的低频扫描探针声学像及其声成像频率特性,揭示了铁电畴的声成像机制源于不同极化取向铁电畴与探针互作用的接触刚性。

  12. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging.

    Science.gov (United States)

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K Kirk; Kim, Hyung Ham

    2015-06-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.

  13. Elastic, dielectric and piezoelectric characterization of single domain PIN-PMN-PT: Mn crystals.

    Science.gov (United States)

    Huo, Xiaoqing; Zhang, Shujun; Liu, Gang; Zhang, Rui; Luo, Jun; Sahul, Raffi; Cao, Wenwu; Shrout, Thomas R

    2012-12-15

    Mn modified 0.26Pb(In(1/2)Nb(1/2))O(3)-0.42Pb(Mg(1/3)Nb(2/3))O(3)-0.32PbTiO(3) (PIN-PMN-PT:Mn) single crystals with orthorhombic perovskite crystal structure were polarized along [011] direction, resulting in the single domain state "1O." The complete set of material constants was determined using the combined resonance and ultrasonic methods. The thickness shear piezoelectric coefficient d(15) and electromechanical coupling factor k(15) were found to be on the order of 3100 pC/N and 94%, respectively, much higher than longitudinal d(33) ∼ 270 pC/N and k(33) ∼ 70%. Using the single domain data, the rotated value of d(33)* along [001] direction was found to be 1230 pC/N, in agreement with the experimentally determined d(33) value of 1370 pC/N, conferring extrinsic contributions being about 10%, which was also confirmed using the Rayleigh analysis. In addition, the mechanical quality factors Q(m) were evaluated for different "1O" vibration modes, where the longitudinal Q(m) was found to be ∼1200, much higher than the value for "4O" crystals, ∼300.

  14. Implementation of a PMN-PT piezocrystal-based focused array with geodesic faceted structure.

    Science.gov (United States)

    Qiu, Zhen; Qiu, Yongqiang; Demore, Christine E M; Cochran, Sandy

    2016-07-01

    The higher performance of relaxor-based piezocrystals compared with piezoceramics is now well established, notably including improved gain-bandwidth product, and these materials have been adopted widely for biomedical ultrasound imaging. However, their use in other applications, for example as a source of focused ultrasound for targeted drug delivery, is hindered in several ways. One of the issues, which we consider here, is in shaping the material into the spherical geometries used widely in focused ultrasound. Unlike isotropic unpoled piezoceramics that can be shaped into a monolithic bowl then poled through the thickness, the anisotropic structure of piezocrystals make it impossible to machine the bulk crystalline material into a bowl without sacrificing performance. Instead, we report a novel faceted array, inspired by the geodesic dome structure in architecture, which utilizes flat piezocrystal material and maximizes fill factor. Aided by 3D printing, a prototype with f#≈ 1.2, containing 96 individually addressable elements was manufactured using 1-3 connectivity PMN-PT piezocrystal-epoxy composite. The fabrication process is presented and the array was connected to a 32-channel controller to shape and steer the beam for preliminary performance demonstration. At an operating frequency of 1MHz, a focusing gain around 30 was achieved and the side lobe intensities were all at levels below -12dB compared to main beam. We conclude that, by taking advantage of contemporary fabrication techniques and driving instrumentation, the geodesic array configuration is suitable for focused ultrasound devices made with piezocrystal.

  15. The most powerful flaring activity from the NLSy1 PMN J0948+0022

    CERN Document Server

    D'Ammando, F; Finke, J; Raiteri, C M; Hovatta, T; Larsson, J; Max-Moerbeck, W; Perkins, J; Readhead, A C S; Richards, J L; Beilicke, M; Benbow, W; Berger, K; Bird, R; Bugaev, V; Cardenzana, J V; Cerruti, M; Chen, X; Ciupik, L; Dickinson, H J; Eisch, J D; Errando, M; Falcone, A; Finley, J P; Fleischhack, H; Fortin, P; Fortson, L; Furniss, A; Gerard, L; Gillanders, G H; Griffiths, S T; Grube, J; Gyuk, G; Hakansson, N; Holder, J; Humensky, T B; Kar, P; Kertzman, M; Khassen, Y; Kieda, D; Krennrich, F; Kumar, S; Lang, M J; Maier, G; McCann, A; Meagher, K; Moriarty, P; Mukherjee, R; Nieto, D; de Bhroithe, A O' Faolain; Ong, R A; Otte, A N; Pohl, M; Popkow, A; Prokoph, H; Pueschel, E; Quinn, J; Ragan, K; Reynolds, P T; Richards, G T; Roache, E; Rousselle, J; Santander, M; Sembroski, G H; Smith, A W; Staszak, D; Telezhinsky, I; Tucci, J V; Tyler, J; Varlotta, A; Vassiliev, V V; Wakely, S P; Weinstein, A; Welsing, R; Williams, D A; Zitzer, B

    2014-01-01

    We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma rays, PMN J0948+0022 ($z$ = 0.5846). A gamma-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 $\\pm$ 31) $\\times$10$^{-8}$ ph cm$^{-2}$ s$^{-1}$ on 2013 January 1, corresponding to an apparent isotropic luminosity of about 1.5$\\times$10$^{48}$ erg s$^{-1}$. The gamma-ray flaring period triggered Swift and VERITAS observations in addition to radio and optical monitoring by OVRO, MOJAVE, and CRTS. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the gamma-ray flare, reaching a record flux for this source from optical to gamma rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6-17 resulted in an upper limit of F (> 0.2 TeV) < 4.0$\\times$10$^{-12}$ ph cm$^{-2}$ s$^{-1}$. W...

  16. Effect of substrates on phase formation in PMN-PT 68/32 thin films by sol-gel process

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P. [Department of Physics, National Institute of Technology, Rourkela 769008 (India)], E-mail: pvn77@rediffmail.com; Sonia; Patel, R.K. [Department of Chemistry, National Institute of Technology, Rourkela 769008 (India); Prakash, C. [DRDO Bhawan, Rajaji Marg, New Delhi 110011 (India); Goel, T.C. [BITS Pilani-Goa Campus, Goa 403720 (India)

    2008-07-15

    PMN-PT 68/32 thin films have been prepared on Pt/Si, ITO coated glass, stainless steel and silicon substrates in the identical processing conditions by sol-gel process. Annealing temperature of 600 deg. C was ascertained by thermo gravimetric analysis (TGA) study of the dried sol-gel powder of PMNT-PT 68/32 composition. X-ray diffraction (XRD) study showed {approx}95% perovskite phase formation on Pt/Si and ITO coated glass substrates. SEM micrographs showed the formation of sub micron size grains on Pt/Si and ITO coated glass substrates. Diffuse phase transition with transition temperature (T{sub c}) {approx}190 deg. C was observed in 0.8 {mu}m thick PMN-PT 68/32 films deposited on Pt/Si and ITO coated glass substrates.

  17. 直流偏压下PMN-32%PT单晶的介电异常变化

    Institute of Scientific and Technical Information of China (English)

    惠增哲; 李振荣; 徐卓; 张良莹; 姚熹

    2003-01-01

    在不同直流偏压下,测试了[001]和[111]方向的PMN-32%PT单晶的介电温度谱, 研究了其介电响应和相变行为. 当施加的偏压在E = 1.5~4.0 kV/cm范围内, 在三方相稳定的温度范围内有一个新的异常介电峰出现; 当E>4.0 kV/cm时, 异常介电峰消失. 而对于[111]方向的单晶, 在偏压下没有新的异常介电峰出现. 对直流偏压下PMN-32%PT单晶的介电异常变化进行了讨论.

  18. Ferroic superglasses: Polar nanoregions in relaxor ferroelectric PMN versus CoFe superspins in a discontinuous multilayer

    Science.gov (United States)

    Kleemann, Wolfgang; Dec, Jan

    2016-11-01

    Superdipolar glass properties of polar nanoregions (PNRs) in relaxor ferroelectric PbM g1 /3N b2 /3O3 (PMN) are compared to those of ferromagnetic nanoparticles (FNPs) in the superspin glass [Co80Fe20(0.9 nm ) /A l2O3(3 nm ) ] 10. Both the dynamic critical properties at T >Tg and nonergodicity phenomena at T FNP, the superspin glass exhibits standard Cole-Cole broadening of the spectrum of relaxation frequencies at all temperatures. Contrastingly, the relaxation spectrum of the PNRs in PMN is subject to a crossover from Lacroix-Béné to Cole-Davidson statistics on cooling toward Tg. Surprisingly, it becomes replaced by relaxation and creeplike domain-wall dynamics below Tg as a consequence of volume percolation of the PNR at Tg and formation of a ferroelectric microdomain state under the simultaneous control by quenched random electric fields and the softening ferroelectric F1 u lattice mode.

  19. Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

    Science.gov (United States)

    Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

    2016-02-01

    We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

  20. Comparative evaluation of levels of C-reactive protein and PMN in periodontitis patients related to cardiovascular disease

    Science.gov (United States)

    Anitha, G.; Nagaraj, M.; Jayashree, A.

    2013-01-01

    Background: Numerous cross-sectional studies have suggested that chronic periodontitis is a risk factor for cardiovascular diseases. There is evidence that periodontitis and cardiovascular diseases are linked by inflammatory factors including C-reactive protein. The purpose of the study was to investigate the levels of CRP and PNM cells as a marker of inflammatory host response in the serum of chronic periodontitis patients and in patients with CVD. Materials and Methods: Study population included 75 patients; both male and female above 35 years were included for the study. The patients were divided into three groups of 25 each – Group I: Chronic periodontitis patients with CVD, Group II: Chronic periodontitis patients without CVD and Group III: Control subjects (without chronic periodontitis and CVD). Patients with chronic periodontitis had ≥8 teeth involved with probing depth (PD) ≥5 mm involved. The control group had PD ≤ 3 mm and no CVD. Venous blood was collected from the patients and C-reactive protein levels were analyzed by immunoturbidimetry. PMN was recorded by differential count method. Results: On comparison, OHI-S Index, GI, mean PD, CRP and PMN values showed significant difference from Group I to III. CRP level was highly significant in Group I when compared with Group II and Group III. PMN level was highly significant in Group I when compared with Group III PMN level which was not significant. Conclusion: This study indicated that periodontitis may add the inflammation burden of the individual and may result in increased levels of CVD based on serum CRP levels. Thus, controlled prospective trials with large sample size should be carried out to know the true nature of the relationship if indeed one exists. PMID:24049333

  1. Migratory patterns and developmental potential of trunk neural crest cells in the axolotl embryo.

    Science.gov (United States)

    Epperlein, Hans-Henning; Selleck, Mark A J; Meulemans, Daniel; Mchedlishvili, Levan; Cerny, Robert; Sobkow, Lidia; Bronner-Fraser, Marianne

    2007-02-01

    Using cell markers and grafting, we examined the timing of migration and developmental potential of trunk neural crest cells in axolotl. No obvious differences in pathway choice were noted for DiI-labeling at different lateral or medial positions of the trunk neural folds in neurulae, which contributed not only to neural crest but also to Rohon-Beard neurons. Labeling wild-type dorsal trunks at pre- and early-migratory stages revealed that individual neural crest cells migrate away from the neural tube along two main routes: first, dorsolaterally between the epidermis and somites and, later, ventromedially between the somites and neural tube/notochord. Dorsolaterally migrating crest primarily forms pigment cells, with those from anterior (but not mid or posterior) trunk neural folds also contributing glia and neurons to the lateral line. White mutants have impaired dorsolateral but normal ventromedial migration. At late migratory stages, most labeled cells move along the ventromedial pathway or into the dorsal fin. Contrasting with other anamniotes, axolotl has a minor neural crest contribution to the dorsal fin, most of which arises from the dermomyotome. Taken together, the results reveal stereotypic migration and differentiation of neural crest cells in axolotl that differ from other vertebrates in timing of entry onto the dorsolateral pathway and extent of contribution to some derivatives.

  2. Moving across the border: Modeling migratory bat populations

    Science.gov (United States)

    Ruscena, Wiederholt; López-Hoffman, Laura; Cline, Jon; Medellin, Rodrigo; Cryan, Paul M.; Russell, Amy; McCracken, Gary; Diffendorfer, Jay; Semmens, Darius J.

    2013-01-01

    The migration of animals across long distances and between multiple habitats presents a major challenge for conservation. For the migratory Mexican free-tailed bat (Tadarida brasiliensis mexicana), these challenges include identifying and protecting migratory routes and critical roosts in two countries, the United States and Mexico. Knowledge and conservation of bat migratory routes is critical in the face of increasing threats from climate change and wind turbines that might decrease migratory survival. We employ a new modeling approach for bat migration, network modeling, to simulate migratory routes between winter habitat in southern Mexico and summer breeding habitat in northern Mexico and the southwestern United States. We use the model to identify key migratory routes and the roosts of greatest conservation value to the overall population. We measure roost importance by the degree to which the overall bat population declined when the roost was removed from the model. The major migratory routes—those with the greatest number of migrants—were between winter habitat in southern Mexico and summer breeding roosts in Texas and the northern Mexican states of Sonora and Nuevo Leon. The summer breeding roosts in Texas, Sonora, and Nuevo Leon were the most important for maintaining population numbers and network structure – these are also the largest roosts. This modeling approach contributes to conservation efforts by identifying the most influential areas for bat populations, and can be used as a tool to improve our understanding of bat migration for other species. We anticipate this approach will help direct coordination of habitat protection across borders.

  3. Telecoupling framework for research on migratory species in the Anthropocene

    Directory of Open Access Journals (Sweden)

    Jacqueline Hulina

    2017-03-01

    Full Text Available Migratory species are an important component of biodiversity and provide essential ecosystem services for humans, but many are threatened and endangered. Numerous studies have been conducted on the biology of migratory species, and there is an increased recognition of the major role of human dimensions in conserving migratory species. However, there is a lack of systematic integration of socioeconomic and environmental factors. Because human activities affect migratory species in multiple places, integrating socioeconomic and environmental factors across space is essential, but challenging. The holistic framework of telecoupling (socioeconomic and environmental interactions over distances has the potential to help meet this challenge because it enables researchers to integrate human and natural interactions across multiple distant places. The use of the telecoupling framework may also lead to new conservation strategies and actions. To demonstrate its potential, we apply the framework to Kirtland’s warblers ('Setophaga kirtlandii' , a conservation-reliant migratory songbird. Results show accomplishments from long-term research and recovery efforts on the warbler in the context of the telecoupling framework. The results also show 24 research gaps even though the species has been relatively well-studied compared to many other species. An important gap is a lack of systematic studies on feedbacks among breeding, wintering, and stopover sites, as well as other “spillover” systems that may affect and be affected by migration (e.g., via tourism, land use, or climate change. The framework integrated scattered information and provided useful insights about new research topics and flow-centered management approaches that encapsulate the full annual cycle of migration. We also illustrate the similarities and differences between Kirtland’s warblers and several other migratory species, indicating the applicability of the telecoupling framework to

  4. Linear Thermal Expansion Measurements of Lead Magnesium Niobate (PMN) Electroceramic Material for the Terrestrial Planet Finder Coronagraph

    Science.gov (United States)

    Karlmann, Paul B.; Halverson, Peter G.; Peters, Robert D.; Levine, Marie B.; VanBuren, David; Dudik, Matthew J.

    2005-01-01

    Linear thermal expansion measurements of nine samples of Lead Magnesium Niobate (PMN) electroceramic material were recently performed in support of NASA's Terrestrial Planet Finder Coronagraph (TPF-C) mission. The TPF-C mission is a visible light coronagraph designed to look at roughly 50 stars pre- selected as good candidates for possessing earth-like planets. Upon detection of an earth-like planet, TPF-C will analyze the visible-light signature of the planet's atmosphere for specific spectroscopic indicators that life may exist there. With this focus, the project's primary interest in PMN material is for use as a solid-state actuator for deformable mirrors or compensating optics. The nine test samples were machined from three distinct boules of PMN ceramic manufactured by Xinetics Inc. Thermal expansion measurements were performed in 2005 at NASA Jet Propulsion Laboratory (JPL) in their Cryogenic Dilatometer Facility. All measurements were performed in vacuum with sample temperature actively controlled over the range of 270K to 3 10K. Expansion and contraction of the test samples with temperature was measured using a JPL developed interferometric system capable of sub-nanometer accuracy. Presented in this paper is a discussion of the sample configuration, test facilities, test method, data analysis, test results, and future plans.

  5. Effects of Sr2+substitution on the structural, dielectric, and piezoelectric properties of PZT-PMN ceramics

    Institute of Scientific and Technical Information of China (English)

    Arvind Kumar; S.K. Mishra

    2014-01-01

    This study described the structural, dielectric, and piezoelectric behavior of Pb1-xSrx[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 ceramics (PSZT-PMN, x=0, 0.025, 0.050, and 0.075), prepared by a semi-wet route. X-ray diffraction, dielectric, and piezoelectric investigations were carried out to analyze the crystal structure. The relative dielectric constant and dielectric loss were both calculated as the functions of temperature. The room-temperature dielectric constant reaches a maximum for a Sr2+-modified PZT-PMN ceramic with an x value of 0.050, which corresponds to the morphotropic phase boundary (MPB). Raman spectroscopy studies also confirm the existence of this MPB for x=0.050. The piezoelectric strain coefficients (d33) value shows a maximum response for this composition. In addition, the phase transition temperature decreases significantly when the Sr2+concentration increases in the PZT-PMN ceramics.

  6. A redshifted Fe K$\\alpha$ line from the unusual gamma-ray source PMN J1603-4904

    CERN Document Server

    Müller, C; Dauser, T; Kreikenbohm, A; Beuchert, T; Kadler, M; Ojha, R; Wilms, J; Böck, M; Carpenter, B; Markowitz, A; McConville, W; Pottschmidt, K; Stawarz, L; Taylor, G B

    2015-01-01

    Multiwavelength observations have revealed the highly unusual properties of the gamma-ray source PMN J1603-4904, which are difficult to reconcile with any other well established gamma-ray source class. The object is either a very atypical blazar or compact jet source seen at a larger angle to the line of sight. In order to determine the physical origin of the high-energy emission processes in PMN J1603-4904, we study the X-ray spectrum in detail. We performed quasi-simultaneous X-ray observations with XMM-Newton and Suzaku in 2013 September, resulting in the first high signal-to-noise X-ray spectrum of this source. The 2-10 keV X-ray spectrum can be well described by an absorbed power law with an emission line at 5.44$\\pm$0.05 keV (observed frame). Interpreting this feature as a K{\\alpha} line from neutral iron, we determine the redshift of PMN J1603-4904 to be z=0.18$\\pm$0.01, corresponding to a luminosity distance of 872$\\pm$54 Mpc. The detection of a redshifted X-ray emission line further challenges the or...

  7. Microscopic evidence of strain-mediated magnetoelectric coupling in Co/Pt multilayers/PMN-PT(011) heterostructures

    Science.gov (United States)

    Sun, Ying; Wang, Wenbo; Wu, Weida; Zheng, Xiaoli; Cai, Jianwang; Zhao, Yonggang; Liu, Ming

    A promising way to control magnetization(M) via an electric field(E-field) is using magnetoelectric(ME) effect in FM/FE heterostructures. We use magnetic(electric) force microscopy(M(e)FM) to study the strain-mediated E-field modulation of M in (Co/Pt)n with perpendicular magnetic anisotropy(PMA) or in-plane anisotropy on PMN-PT(011) substrates. MFM were performed on (Co/Pt)n with an DC E-field applied to PMN-PT. In MeFM, we superimpose an AC modulation on a DC one and utilize lock-in technique to detect weak ME effect. For (Co/Pt)n with PMA, MFM images show stripe domains with no obvious changes at varied DC E-fields. However, MeFM shows interesting structures and the image contrast reverses sign at opposite strain slopes of the PMN-PT substrate. For sample with in-plane anisotropy, both MFM and MeFM images show dipole-like domains. Interestingly, the MeFM image contrast reverses sign at opposite strain slopes of the substrate. The sign reversal of MeFM contrast indicates that features revealed by MeFM are intrinsic local ME effect. Our MeFM data are consistent with the ferromagnetic resonance results showing that strain-induced anisotropy change will cause part of M switching to the in-plane direction. Possible scenarios will be discussed.

  8. In situ hard x-ray photoemission spectroscopy of barrier-height control at metal/PMN-PT interfaces

    Science.gov (United States)

    Kröger, E.; Petraru, A.; Quer, A.; Soni, R.; Kalläne, M.; Pertsev, N. A.; Kohlstedt, H.; Rossnagel, K.

    2016-06-01

    Metal-ferroelectric interfaces form the basis of novel electronic devices. A key effect determining the device functionality is the bias-dependent change of the electronic energy-level alignment at the interface. Here, hard x-ray photoelectron spectroscopy (HAXPES) is used to determine the energy-level alignment at two metal-ferroelectric interfaces—Au versus SrRuO3 on the relaxor ferroelectric Pb (Mg1 /3Nb2 /3 )0.72Ti0.28O3 (PMN-PT)—directly in situ as a function of electrical bias. The bias-dependent average shifts of the PMN-PT core levels are found to have two dominant contributions on the 0.1 -1-eV energy scale: one depending on the metal electrode and the remanent electric polarization and the other correlated with electric-field-induced strain. Element-specific deviations from the average shifts are smaller than 0.1 eV and appear to be related to predicted dynamical charge variations in PMN-PT. In addition, the efficiency of ferroelectric polarization switching is shown to be reduced near the coercive field under x-ray irradiation. The results establish HAXPES as a tool for the in operando investigation of metal-ferroelectric interfaces and suggest electric-field-induced modifications of the polarization distribution as a novel way to control the barrier height at such interfaces.

  9. Effects of Methanolic Jatropha multifida L. Extract in Wound Healing Assessed by the Total Number of PMN Leukocytes and Fibroblasts

    Directory of Open Access Journals (Sweden)

    Juniarti

    2012-12-01

    Full Text Available Objective: The aim of this study was to evaluate the effects of methanol extract of Jatropha multifida leaves on the wound healing process and to investigate the wound healing activity based on reduced numbers of PMN (polymorpho nuclear leukocytes and increased numbers of fibroblasts. Method: methanol extract of dried leaves of Jatropha multifida was used in the wound healing activity studies. The study subjects were 36 white male Sprague Dawlay rats aged 2 months with 150-200 gram body weight. The subjects were divided into 4 groups and experimentally injured: Group I (negative control underwent injury without subsequent treatment; group II (positive control received topical treatment with Bethasone-N after injury; group III (solvent control was treated with 70% methanol; group IV (treatment group was treated with 10 mg methanol extract of Jatropha multifida Each group consisted of 3 rats, which were decapitated on days 3, 6, and 13 after the start of treatment. Histological preparation was stained with hematoxyline-eosin (HE and was continuously examined by counting the numbers of PMN leukocytes and fibroblasts as indicators of wound healing on days 3, 6, and 13 of treatment. The study showed lower numbers of PMN leukocytes in subjects treated with the extract of Jatropha multifida as compared to the other groups. The numbers of fibroblasts were significantly higher on days 6 and 13 of treatment. In conclusion, the treatment of injuries with methanol extract of leaves from Jatropha multifida provided better results compared to the other groups in our study.

  10. Conception, Modélisation, Fabrication et Contrôle des systèmes piézoélectriques en PMN-PT.

    OpenAIRE

    CIUBOTARIU, Adrian

    2016-01-01

    This work proposes the use of a novel material, called PMN-PT, that futher aids the miniaturization of complex systems used in different technologies. The work is presented within the collaborative framework of two projects, MIOP and ADMAN. The end-needs account for actuators capable of delivering high displacement, while maintaining system simplicity and reliability. The focus is on the versatility of the PMN-PT piezoelectric material, due to its electro-mechanical properties. The work inclu...

  11. Piezo-phototronic effect-induced dual-mode light and ultrasound emissions from ZnS:Mn/PMN-PT thin-film structures.

    Science.gov (United States)

    Zhang, Yang; Gao, Guanyin; Chan, Helen L W; Dai, Jiyan; Wang, Yu; Hao, Jianhua

    2012-04-03

    Electric-field-controllable luminescence of a ZnS:Mn/PMN-PT system is demonstrated. The light-emission of ZnS:Mn is caused by the piezoelectric potential, resulting from the converse piezoelectric effect of the PMN-PT substrate. Simultaneous generation of light and ultrasound waves is observed in this single system, which offers great potential to develop a dual-modal source combing light and ultrasonic waves for various applications.

  12. Migratory fat deposition in European quail: a role for prolactin?

    Science.gov (United States)

    Boswell, T; Sharp, P J; Hall, M R; Goldsmith, A R

    1995-07-01

    The present study addresses the role of prolactin as a regulator of migratory fattening in European quail (Coturnix coturnix). Plasma prolactin levels in captive birds undergoing migratory fattening in an outdoor aviary and in the laboratory were measured by radioimmunoassay with an antibody raised against recombinant-derived chicken prolactin. No strong association between prolactin and migratory fattening was apparent, and prolactin levels were more closely related to daylength, with the highest concentrations being reached on long days. Plasma prolactin profiles were similar in intact and castrated male quail. Prolactin was secreted in a daily rhythm, with the highest concentrations occurring early in the photophase. However, when birds were food-restricted for 50 days during a migratory phase, there was no difference in fat deposition between birds food-deprived for the first half of the daily photophase compared with those deprived for the second half. Fattening was reduced in the food-restricted birds relative to ad libitum-fed controls, but there was no difference in plasma prolactin levels between the groups. Injections of ovine prolactin (4 mg/kg) significantly increased food intake and body mass of birds maintained on long days, but there were no differences in fattening between birds injected in the morning compared with those injected in the afternoon. Collectively, these results do not support a major role for prolactin in the regulation of migratory fat deposition in European quail.

  13. Effect of Elevated Pressure on the Heat Transfer and Power Requirements During Bridgman Growth of PMN-PT Crystals

    Science.gov (United States)

    Bune, Andris; Ostrogorsky, Aleksandar; Marin, Carlos; Nicoara, Irina; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Performance of the furnace during Bridgman growth of the lead magnesium niobate-lead titanate crystal (PMN-PT) is analyzed. PMN-PT is electrostrictive ceramic that has near ideal strain-voltage function. Furthermore piezoelectric (2000 to 2300 pC/N) and coupling (92 to 95%) constants are exceptionally good. Due to these properties PMN-PT has wide range of applications - from sonars to transducers in a high precision optical systems. In this research first attempt to crystallize PMN-PT in a Mellen type vertical Bridgman furnace was not successful, as melting temperature of precursor materials was not achieved. At this point choice was between building a new more powerful facility or finding ways to enhance performance of the existing furnace. Besides adjusting power supply to the individual heating elements, redesigning ampoule holding cartridge and improving furnace insulation one more radical improvement was proposed. The entire furnace was placed into the high pressure chamber. Further experiments confirmed that temperature inside the furnace was increased sufficiently to melt precursor materials to obtain PMN-PT. Numerical modeling is undertaken to find limitations of this technique and to predict temperature distribution inside the ampoule. It is of interest also to account for main factors contributing to a higher temperatures achieved in the furnace under the higher pressure (up to 10 atm.). Numerical model of the furnace is based on general purpose finite - element code FIDAP and on previous efforts to model Bridgman type furnace with multiply heaters. In order to account for all heat transfer mechanism involved - conduction, convection and radiation - different parts of the furnace are modeled in accordance with expected dominant mode of heat transfer - conduction in the solid parts, conduction and radiation in the ampoule, gas convection and conduction in the furnace openings complemented with wall-to-wall radiation. Because of these complicating factors

  14. Effect of Elevated Pressure on the Heat Transfer and Power Requirements During Bridgman Growth of PMN-PT Crystals

    Science.gov (United States)

    Bune, Andris; Ostrogorsky, Aleksandar; Marin, Carlos; Nicoara, Irina; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Performance of the furnace during Bridgman growth of the lead magnesium niobate-lead titanate crystal (PMN-PT) is analyzed. PMN-PT is electrostrictive ceramic that has near ideal strain-voltage function. Furthermore piezoelectric (2000 to 2300 pC/N) and coupling (92 to 95%) constants are exceptionally good. Due to these properties PMN-PT has wide range of applications - from sonars to transducers in a high precision optical systems. In this research first attempt to crystallize PMN-PT in a Mellen type vertical Bridgman furnace was not successful, as melting temperature of precursor materials was not achieved. At this point choice was between building a new more powerful facility or finding ways to enhance performance of the existing furnace. Besides adjusting power supply to the individual heating elements, redesigning ampoule holding cartridge and improving furnace insulation one more radical improvement was proposed. The entire furnace was placed into the high pressure chamber. Further experiments confirmed that temperature inside the furnace was increased sufficiently to melt precursor materials to obtain PMN-PT. Numerical modeling is undertaken to find limitations of this technique and to predict temperature distribution inside the ampoule. It is of interest also to account for main factors contributing to a higher temperatures achieved in the furnace under the higher pressure (up to 10 atm.). Numerical model of the furnace is based on general purpose finite - element code FIDAP and on previous efforts to model Bridgman type furnace with multiply heaters. In order to account for all heat transfer mechanism involved - conduction, convection and radiation - different parts of the furnace are modeled in accordance with expected dominant mode of heat transfer - conduction in the solid parts, conduction and radiation in the ampoule, gas convection and conduction in the furnace openings complemented with wall-to-wall radiation. Because of these complicating factors

  15. Anisotropic Laminar Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    Science.gov (United States)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2006-01-01

    The design, fabrication, and testing of a flexible, laminar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d33 piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d33 estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  16. Anisotropic Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    Science.gov (United States)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2004-01-01

    The design, fabrication, and testing of a flexible, planar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d(sub 33) piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d(sub 33) estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  17. Winter Latitudinal Population Age-Structure of a Migratory Seagull (Larus fuscus Differs between Its Two Major Migratory Flyways

    Directory of Open Access Journals (Sweden)

    Paulo A. M. Marques

    2013-01-01

    Full Text Available The migration is energy-demanding and is expected to greatly affect the distribution of individuals over the species range and condition the choice of migratory routes. We investigated the wintering distributions and migratory flyways use of geographically contiguous populations of Lesser Black-backed Gulls (Larus fuscus and difference in population winter age structure between migratory flyways. Recoveries of metal ringed pulli from Denmark, Sweden, and Finland were used. The results showed that contiguous populations can have distinct wintering distribution patterns and migratory flyways. More importantly, we found that depending on the place of origin, the population winter distribution may or may not show a latitudinal cline in the age structure. The population migrating via the eastern Atlantic flyway (western flyway showed a winter age-related latitudinal cline, with adults staying at more northern latitudes than immatures. In contrast, no such pattern was found in the population migrating along the Mediterranean/Black sea flyway (eastern flyway. Interestingly, immatures within the eastern population showed a more dispersed pattern of migratory bearings. Overall, our results enhance the importance of the migration flyway in shaping the age structure of populations in the winter quarters and how it may influence the effect of other factors like sexual maturation.

  18. EGF-induced expansion of migratory cells in the rostral migratory stream.

    Directory of Open Access Journals (Sweden)

    Olle R Lindberg

    Full Text Available The presence of neural stem cells in the adult brain is currently widely accepted and efforts are made to harness the regenerative potential of these cells. The dentate gyrus of the hippocampal formation, and the subventricular zone (SVZ of the anterior lateral ventricles, are considered the main loci of adult neurogenesis. The rostral migratory stream (RMS is the structure funneling SVZ progenitor cells through the forebrain to their final destination in the olfactory bulb. Moreover, extensive proliferation occurs in the RMS. Some evidence suggest the presence of stem cells in the RMS, but these cells are few and possibly of limited differentiation potential. We have recently demonstrated the specific expression of the cytoskeleton linker protein radixin in neuroblasts in the RMS and in oligodendrocyte progenitors throughout the brain. These cell populations are greatly altered after intracerebroventricular infusion of epidermal growth factor (EGF. In the current study we investigate the effect of EGF infusion on the rat RMS. We describe a specific increase of radixin(+/Olig2(+ cells in the RMS. Negative for NG2 and CNPase, these radixin(+/Olig2(+ cells are distinct from typical oligodendrocyte progenitors. The expanded Olig2(+ population responds rapidly to EGF and proliferates after only 24 hours along the entire RMS, suggesting local activation by EGF throughout the RMS rather than migration from the SVZ. In addition, the radixin(+/Olig2(+ progenitors assemble in chains in vivo and migrate in chains in explant cultures, suggesting that they possess migratory properties within the RMS. In summary, these results provide insight into the adaptive capacity of the RMS and point to an additional stem cell source for future brain repair strategies.

  19. Counterintuitive roles of experience and weather on migratory performance

    Science.gov (United States)

    Rus, Adrian I.; Duerr, Adam E.; Miller, Tricia A.; Belthoff, James R; Katzner, Todd E.

    2017-01-01

    Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data (n = 37). Spring migrant eagles traveled 139.75 ± 82.19 km day−1 (mean ± SE; n = 57) and 25.59 ± 11.75 km hr−1 (n = 55). Autumn migrant eagles traveled 99.14 ± 59.98 km day−1 (n = 26) and 22.18 ± 9.18 km hr−1 (n = 28). Weather during migration varied by season and by age class. During spring, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by downward solar radiation and that older birds benefited less from flow assistance (tailwinds). During autumn, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most strongly by south–north winds and by flow assistance, again less strongly for older birds. In contrast, models for hourly performance based on data collected at 30 s intervals were not well described by a single model, likely reflecting eagles' rapid responses to the many weather conditions they experienced. Although daily speed of travel was similar for all age classes, younger birds traveled at faster hourly speeds than did adults. Our analyses uncovered strong, sometimes counterintuitive, relationships among weather, experience, and migratory flight, and they illustrate the significance of factors other than age in determining migratory performance.

  20. Acephate affects migratory orientation of the white-throated sparrow (Zonotrichia albicollis)

    Science.gov (United States)

    Vyas, N.B.; Kuenzel, W.J.; Hill, E.F.; Sauer, J.R.

    1995-01-01

    Migratory white-throated sparrows (Zonotrichia albicollis) were exposed to acephate (acetylphosphoramidothioic acid O,S-dimethyl ester), an organophosphorus pesticide, to determine its effects on migratory orientation and behavior. Birds were also exposed to polarizer sheets to determine the mechanism by which acephate may affect migratory orientation. Adult birds exposed to 256 ppm acephate a.i. were not able to establish a preferred migratory orientation and exhibited random activity. All juvenile treatment groups displayed a seasonally correct southward migratory orientation. We hypothesize that acephate may have produced aberrant migratory behavior by affecting the memory of the migratory route and wintering ground. This experiment reveals that an environmentally relevant concentration of a common organophosphorus pesticide can alter migratory orientation, but its effect is markedly different between adult and juvenile sparrows. Results suggest that the survival of free-flying adult passerine migrants may be compromised following organophosphorus pesticide exposure.

  1. Annual Hunting Program : Migratory Waterfowl : Parker River National Wildlife Refuge : 1992-1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This 1992-93 Annual Migratory Waterfowl Hunting Program outlines the reasons and regulations for migratory waterfowl hunting on Parker River National Wildlife...

  2. Annual Hunting Program : Migratory Waterfowl : Parker River National Wildlife Refuge : 1985-86

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This 1985-86 Annual Migratory Waterfowl Hunting Program outlines the reasons and regulations for migratory waterfowl hunting on Parker River National Wildlife...

  3. Shape up or ship out: Migratory behaviour predicts morphology across spatial scale in a freshwater fish

    DEFF Research Database (Denmark)

    Chapman, B.B.; Hulthén, K.; Brönmark, C.;

    2015-01-01

    Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body...

  4. Migratory pathways of GABAergic interneurons when they enter the neocortex.

    Science.gov (United States)

    Tanaka, Daisuke H; Nakajima, Kazunori

    2012-06-01

    Inhibitory gamma-aminobutyric-acid-containing interneurons play important roles in the functions of the neocortex. During rodent development, most neocortical interneurons are generated in the subpallium and migrate tangentially toward the neocortex. They migrate through multiple pathways to enter the neocortex. Failure of interneuron migration through these pathways during development leads to an abnormal distribution and abnormal functions of interneurons in the postnatal brain. Because of recent discoveries regarding the novel origins and migratory pathways of neocortical interneurons, in this article we review the literature on the migratory pathways of interneurons when they enter the neocortex.

  5. Study on Electro-Optic Effect of PMN-PT Ceramics Using Goos-H(a)nchen Shift%用古斯-亨兴位移研究PMN-PT电光陶瓷的电光效应

    Institute of Scientific and Technical Information of China (English)

    冉茂武; 曹庄琪; 陈险峰; 陈凡

    2011-01-01

    根据对称金属包覆电光波导中本征损耗与古斯-亨兴(Goos- H(a)nchen)位移的理论公式,导出了古斯-亨兴位移与作用于波导两侧电压的二次关系公式.用622 μm厚度的四方相铌镁酸铅-钛酸铅(PMN-PT)透明电光陶瓷片作为导波层制备了对称金属包覆波导,测量了古斯-亨兴位移与作用于波导两侧电压的关系曲线,计算了所用透明电光陶瓷片的二次电光系数.实验结果与理论分析一致.%The Goos-Hanchen shift at both sides of the waveguide is conducted, which gives rise to a quadric-curve relation between Goos-Hanchen shift and the applied voltage, based on the theoretical analysis of the intrinsic loss in a symmetrical metal-cladding electro-optic waveguide. A symmetrical metal-cladding waveguide is fabricated with a 622 pan-thick Pb(Mg1/3 Nb2/3 O3 )-PbTiO3 (PMN-PT) transparent ceramic which serves as the guiding layer of the waveguide. Measurements of the relation between Goos-Hanchen shift and the applied voltage are carried out and the quadratic electro-optic coefficient of the PMN-PT ceramic is obtained. Experimental results are agreed well with the numerical simulations.

  6. PMN-PZN-PT铁电陶瓷的准同型相界及电学性能%Morphotropic Phase Boundary and Electrical Properties of PMN-PZN-PT Ceramics

    Institute of Scientific and Technical Information of China (English)

    陈焱; 张孝文

    2009-01-01

    基于准同型相界(morphotropic phase boundary, MPB) 线性组合规律,研究Pb(Mg_(1/3)Nb_(2/3))O_3 -Pb(Zn_(1/3)Nb_(2/3))O_3-PbTiO_3 (PMN-PZN-PT)三元系的MPB区域,并探求电学性能优越的组分.实验选取(1-x) (0.67 PMN- 0.33 PT)-x(0.91 PZN-0.09 PT) 系列中x=0~0.85的8个实验点;为减少焦绿石相的生成,陶瓷试样用铌铁矿预产物法合成,最终在1120~1160 ℃烧成.X射线衍射分析表明该系列试样均为钙钛矿结构,且处于四方与菱方两相共存态,验证了两个子二元系MPB组分的连线均为该三元系的MPB区域.少量的PZN-PT取代PMN-PT可以提高该三元系的电学性能;在x=0.1的组分获得该系列的最优性能:极值介电常数ε_(m,1 kHz)=28 030,剩余极化强度Pr=32.5 μC/cm~2,压电系数d_(33)=545 pC/N.

  7. The influence of quenching process on the dielectric character in single crystal PMN-PT%PMN-PT单晶淬火处理对介电性能的影响

    Institute of Scientific and Technical Information of China (English)

    闫宗林; 姚熹; 张良莹; 严辉

    2004-01-01

    通过淬火处理可以使弛豫型PMN-PT单晶中一些应力集中的区域产生应力场致相变,在Td处产生宏畴,从而在温谱上Td处的介电峰强化.研究表明,经淬火处理单晶谐振极化所对应的低温介电行为受到压制,主介电峰变窄,峰值变高并稍向高温方向移动;频率弥散减弱,弛豫性变小.

  8. PMN-PT陶瓷的制备及介电性能%PREPARATION OF 0.8PMN-0.2PT CERAMICS BY MOLTEN SALT SYNTHESIS AND ITS DIELECTRIC PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    杨祖培; 屈绍波; 高峰; 田长生

    2000-01-01

    采用NaCl-KCl熔盐法制备了钙钛矿相结构的0.8PMN-0.2PT陶瓷,研究了预烧温度、烧结温度和时间等工艺参数对样品的相结构、微观结构以及介电性能的影响,与传统陶瓷工艺相比,用熔盐法制备的样品介电性能好.

  9. 75 FR 56555 - Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry

    Science.gov (United States)

    2010-09-16

    ... Fish and Wildlife Service Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry AGENCY... FURTHER INFORMATION CONTACT: Dr. George Allen, Division of Migratory Bird Management, U.S. Fish and... derived from the Migratory Bird Treaty Act (16 U.S.C. 703-712), which prohibits any person from...

  10. 50 CFR 92.6 - Use and possession of migratory birds.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Provisions § 92.6 Use and possession of migratory birds. You may not sell, offer for sale, purchase, or...

  11. Migratory divides and their consequences for dispersal, population size and parasite-host interactions.

    Science.gov (United States)

    Møller, A P; Garamszegi, L Z; Peralta-Sánchez, J M; Soler, J J

    2011-08-01

    Populations of migratory birds differ in their direction of migration with neighbouring populations often migrating in divergent directions separated by migratory divides. A total of 26% of 103 passerine bird species in Europe had migratory divides that were located disproportionately often along a longitudinal gradient in Central Europe, consistent with the assumption of a Quaternary glacial origin of such divides in the Iberian and Balkan peninsulas followed by recolonization. Given that studies have shown significant genetic differentiation and reduced gene flow across migratory divides, we hypothesized that an absence of migratory divides would result in elevated rates of gene flow and hence a reduced level of local adaptation. In a comparative study, species with migratory divides had larger population sizes and population densities and longer dispersal distances than species without migratory divides. Species with migratory divides tended to be habitat generalists. Bird species with migratory divides had higher richness of blood parasites and higher growth rates of Staphylococcus on their eggs during the incubation period. There was weaker cell-mediated immunity in adults and stronger cell lysis in species with migratory divides. These findings may suggest that migratory divides constitute barriers to dispersal with consequences for ecology and evolution of distributions, population sizes, habitats and parasite-host interactions. They also suggest that migratory divides may play a role in local adaptation in host-parasite interactions.

  12. 75 FR 8989 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Science.gov (United States)

    2010-02-26

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  13. 77 FR 5264 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Science.gov (United States)

    2012-02-02

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  14. 76 FR 5820 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Science.gov (United States)

    2011-02-02

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  15. 77 FR 39983 - Migratory Bird Hunting; Application for Approval of Fluoropolymeric Shot Coatings as Nontoxic for...

    Science.gov (United States)

    2012-07-06

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY66 Migratory Bird Hunting; Application for Approval... INFORMATION CONTACT: George Allen, at 703-358-1825. SUPPLEMENTARY INFORMATION: Background The Migratory Bird Treaty Act of 1918 (Act) (16 U.S.C. 703-712 and 16 U.S.C. 742 a-j) implements migratory bird...

  16. Microwave Magnetoelectric Effects in Single Crystal YIG/PMN-PT Bilayers

    Science.gov (United States)

    Shastry, S.; Srinivasan, G.; Mantese, J. V.

    2004-03-01

    Layered magnetostrictive/piezoelectric structures are multifunctional due to mechanical force mediated electromagnetic coupling. This study is concerned with microwave magnetoelectric (ME) interactions in layered ferrite-piezoelectric oxides. Ferromagnetic resonance (FMR) is a powerful tool for such studies. An electric field E applied to the composite produces a mechanical deformation in PZT that in turn is coupled to the ferrite, resulting in a shift in the resonance field. Information on the nature of high frequency ME coupling could therefore be obtained from data on field shift vs E. Since the measurement accuracy depends very much on the FMR line width, bilayers consisting of single crystal or epitaxial low-loss ferrites are ideal for the investigations. Studies were performed at 9.4 GHz on bilayers consisting of (100), (110) or (111) epitaxial yttrium iron garnet (YIG) films (1-130 micron) and (100) lead magnesium niobate-lead titanate (PMN-PT). The samples were positioned outside a hole at the bottom or side of a TE102-reflection type cavity. Resonance absorption vs bias magnetic field H were obtained as a function of E = 0-8 kV/cm for both in-plane and out-of-plane H. Important results are as follows. (i) The ME coupling is stronger for H perpendicular to the bilayer than for in-plane H. (ii) The coupling strength is maximum for E and H along in YIG. (iii) The ME constant varies from a maximum of 6 Oe cm/kV for bilayers with 4 micron YIG to a minimum of 3 Oe cm/kV for 110 micron YIG. (iv) The variation of resonance field shift with the volume ratio for the two phases is in agreement with theory [1,2]. 1. M. I. Bichurin, I. A. Kornev, V. M. Petrov, A. S. Tatarenko, Yu. V. Kiliba, and G. Srinivasan, Phys. Rev. B 64, 094409 (2001). 2. M. I. Bichurin, V. M. Petrov, Yu. V. Kiliba, G. Srinivasan, Phys. Rev. B 66, 134404 (2002). This work was supported by a grant from the National Science Foundation (DMR-0322254)

  17. Doxycycline inhibits neutrophil (PMN)-type matrix metalloproteinases in human adult periodontitis gingiva.

    Science.gov (United States)

    Golub, L M; Sorsa, T; Lee, H M; Ciancio, S; Sorbi, D; Ramamurthy, N S; Gruber, B; Salo, T; Konttinen, Y T

    1995-02-01

    We previously reported that low-dose doxycycline (DOXY) therapy reduces host-derived collagenase activity in gingival tissue of adult periodontitis (AP) patients. However, it was not clear whether this in vivo effect was direct or indirect. In the present study, inflamed human gingival tissue, obtained from AP patients during periodontal surgery, was extracted and the extracts partially purified by (NH4)2SO4 precipitation. The extracts were then analyzed for collagenase activity using SDS-PAGE/fluorography/laser densitometry, and for gelatinase activity using type I gelatin zymography as well as a new quantitative assay using biotinylated type I gelatin as substrate. DOXY was added to the incubation mixture at a final concentration of 0-1000 microM. The concentration of DOXY required to inhibit 50% of the gingival tissue collagenase (IC50) was found to be 16-18 microM in the presence or absence of 1.2 mM APMA (an optimal organomercurial activator of latent procollagenases); this IC50 for DOXY was similar to that exhibited for collagenase or matrix metalloproteinase (MMP)-8 from polymorphonuclear leukocytes (PMNs) and from gingival crevicular fluid (GCF) of AP patients. Of interest, Porphyromonas gingivalis collagenase was also inhibited by similar DOXY levels (IC50 = 15 microM), however the collagenase activity observed in the gingival tissue extracts was found to be of mammalian not bacterial origin based on the production of the specific alpha A (3/4) and alpha B (1/4) collagen degradation fragments. In contrast, the inhibition of collagenase purified from culture media of human gingival fibroblasts (MMP-1) required much greater DOXY levels (IC50 = 280 microM). The predominant molecular forms of gelatinolytic activity presented in the AP patients gingival tissue extracts were found to closely correspond to the 92 kD PMN-type gelatinase (MMP-9) although small quantities of 72 kD fibroblast-type gelatinase (MMP-2), and some other low molecular weight gelatinases

  18. Magnetoelectric properties of particulate and bi-layer PMN-PT/CoFe{sub 2}O{sub 4} composites

    Energy Technology Data Exchange (ETDEWEB)

    Mathe, V.L., E-mail: vlmathe@physics.unipune.ernet.in [Novel Materials Research Laboratory, Department of Physics, University of Pune, Pune, 411 007 Maharastra (India); Sheikh, A.D. [Novel Materials Research Laboratory, Department of Physics, University of Pune, Pune, 411 007 Maharastra (India); Srinivasan, G. [Physics Department, Oakland University, Rochester, MI 48309 (United States)

    2012-03-15

    Our studies comprise electrical dielectric and magnetoelectric properties of CoFe{sub 2}O{sub 4} (CFO) and Pb(Mg{sub 1/3}Nb{sub 2/3}){sub 0.67}Ti{sub 0.33}O{sub 3} [PMN-PT] magnetoelectric composites. The individual phases were prepared by conventional ceramic method. The particulate composites of ferrite and ferroelectric phases were prepared in ferroelectric rich region. Presence of both the phases in the composites was confirmed using X-ray diffraction techniques. The scanning electron microscopic images recorded in backscattered mode were used to study the microstructure of composites. Lattice constant, dielectric constant, electrical resistivity, ferroelectric, and magnetic properties of individual as well as particulate composites were studied. Further the bi-layer composites were made using the discs obtained from the powders of individual phases where hot press technique was employed to obtain disc of individual phases. CFO phase used in bi-layer composites was obtained using chemical co-precipitation technique. Magnetoelectric (ME) measurements were carried out on both, particulate and layered magnetoelectric composites. Comparison of ME signal obtained from particulate and layered composites revealed that the layered composites gives superior magnetoelectric signal. ME data obtained for layered composites show good agreement with the theoretical model. - Highlights: Black-Right-Pointing-Pointer Study on dielectric, electrical, ferroelectric, and magnetic properties of particulate magnetoelectric composite of PMN-PT/CFO. Black-Right-Pointing-Pointer These properties are correlated with the magnetoelectric effect in particulate composites. Black-Right-Pointing-Pointer Magnetoelectric properties of particulate composites are compared with bilayer magnetoelectric composites of PMN-PT/CFO. Black-Right-Pointing-Pointer Magnetoelectric signal obtain for bilayer composites show good agreement with theoretical model suggested by Bichurin et al.

  19. Phase structure and electrical properties of PSN-PMN-PZ-PT quaternary piezoelectric ceramics near the morphotropic phase boundary

    Science.gov (United States)

    Chen, Haiyan; Fan, Chunhua

    2010-04-01

    0.06Pb(Sb 1/2Nb 1/2)O 3-0.06Pb(Mn 1/3Nb 2/3)O 3-0.88Pb(Zr xTi 1-x)O 3 (PSN-PMN-PZ-PT) quaternary piezoelectric ceramics with varying Zr/Ti ratios located near the morphotropic phase boundary (MPB) were prepared by powder solid-state reaction. The phase structure, dielectric and piezoelectric properties and temperature stability of the systems were investigated. In the present system the MPB, in which the tetragonal and rhombohedral phases coexist, is in a composition range of 0.49ultrasonic motors.

  20. 75 FR 9281 - General Provisions; Revised List of Migratory Birds

    Science.gov (United States)

    2010-03-01

    ... Protection of Migratory Birds and Game Mammals, February 7, 1936, United States-United Mexican States (Mexico... York (AOU 1982, 1983, 1998); Flycatcher, La Sagra's, Myiarchus sagrae--Alabama, Florida (AOU 1982, 1983..., Motacilla citreola--Alabama (AOU 1995, 1998); Warbler, Crescent-chested, Parula superciliosa--Arizona...

  1. REGULATION OF MIGRATORY PROCESSES AS BASIS OF RUSSIAN NATIONAL SECURITY

    Directory of Open Access Journals (Sweden)

    V. A. Silantyeva

    2016-01-01

    Full Text Available The article deals with modern problems of migration, given the attempt to identify the causes of the migratory crisis in Europe, shows the state migration policy of Russia. Despite features of migration policy in separately taken European state, consequences of migratory processes for the countries of Europe the general. In Russia long time there was no complete system of the migratory legislation. However in recent years Russia has considerably progressed in the solution of migratory problems: the Concept of the state migration policy of the Russian Federation for the period till 2025 within which the principles and the main activities of the Russian Federation in the sphere of migration are established is accepted. It, in our opinion, has allowed reducing the number of labor migrants and those who illegally work in the territory of the Russian Federation. Based on the study of existing theoretical approaches, standards and applicable regulations made some conclusions about the nature of migration control. It was found that the effective implementation of the state migration policy will contribute to socioeconomic and demographic development, national security and maintain stability in society.

  2. Intra-articular regional migratory osteoporosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Wambeek, N.; Munk, P.L.; Lee, M.J. [Dept. of Radiology, Vancouver General Hospital, BC (Canada); University of British Columbia, Vancouver (Canada); Meek, R.N. [Department of Orthopedic Surgery, Vancouver General Hospital, Vancouver (Canada)

    2000-02-01

    We report a case of lntra-articular regional migratory osteoporosis of the knee in a 53-year-old man. The case demonstrates an unusual pattern of migration of the marrow edema within the knee joint. This phenomenon has received scant attention in the radiological literature. (orig.)

  3. Experimental temperature manipulations alter songbird autumnal nocturnal migratory restlessness

    Directory of Open Access Journals (Sweden)

    Berchtold Adrienne

    2017-02-01

    Full Text Available Migrating birds may respond to a variety of environmental cues in order to time migration. During the migration season nocturnally migrating songbirds may migrate or stop-over at their current location, and when migrating they may vary the rate or distance of migration on any given night. It has long been known that a variety of weather-related factors including wind speed and direction, and temperature, are correlated with migration in free-living birds, however these variables are often correlated with each other. In this study we experimentally manipulated temperature to determine if it would directly modulate nocturnal migratory restlessness in songbirds. We experimentally manipulated temperature between 4, 14, and 24°C and monitored nocturnal migratory restlessness during autumn in white-throated sparrows (Zonotrichia albicollis. White-throated sparrows are relatively shortdistance migrants with a prolonged autumnal migration, and we thus predicted they might be sensitive to weatherrelated cues when deciding whether to migrate or stopover. At warm temperatures (24°C none of the birds exhibited migratory restlessness. The probability of exhibiting migratory restlessness, and the intensity of this restlessness (number of infra-red beam breaks increased at cooler (14°C, 4°C temperatures. These data support the hypothesis that one of the many factors that birds use when making behavioural decisions during migration is temperature, and that birds can respond to temperature directly independently of other weather-related cues.

  4. 77 FR 70551 - Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2012-11-26

    ... Part 635 Highly Migratory Species; Atlantic Shark Management Measures; Proposed Rule #0;#0;Federal...; Atlantic Shark Management Measures AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... shark stock assessments that were completed from 2009 to 2012. The assessments for Atlantic...

  5. Death and danger at migratory stopovers: Problems with "predation risk"

    NARCIS (Netherlands)

    Lank, D.B.; Ydenberg, R.C.

    2003-01-01

    Dierschke (2003) recently published a paper entitled, ``Predation hazard during migratory stopover: are light or heavy birds under risk?¿¿ He measured the body condition of 11 species of passerine migrants depredated by feral cats and raptors at an offshore stopover site, and used these data to

  6. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    Science.gov (United States)

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  7. 76 FR 67650 - Migratory Bird Permits; Abatement Regulations

    Science.gov (United States)

    2011-11-02

    ... for a specific permit authorizing the use of raptors in abatement activities (76 FR 39368). The... the advance notice of proposed rulemaking, please refer to that document at 76 FR 39368 (July 6, 2011... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement...

  8. Status and management of neotropical migratory birds: Introduction

    Science.gov (United States)

    Deborah M.; Peter W. Stangel

    1993-01-01

    The future for neotropical migratory birds rests with our commitment and ability to provide them adequate habitat during all periods of their life cycle. Our commitment to this cause is apparent in the groundswell of interest in neotropical migrants and the many proactive and coopemtive partnerships resulting from the Partners in Flight - Aves de las Americas...

  9. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics.

    Science.gov (United States)

    Smith, W E; Kwak, T J

    2014-04-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  10. 75 FR 9314 - Migratory Bird Permits; Control of Purple Swamphens

    Science.gov (United States)

    2010-03-01

    ... with governance of migratory bird permitting in the United States. No other Federal agency has any role... Environmental Policy Act We have analyzed this rule in accordance with the National Environmental Policy Act of... and its territories in which the species may have been introduced. The environmental impacts...

  11. Wet season range fidelity in a tropical migratory ungulate.

    Science.gov (United States)

    Morrison, Thomas A; Bolger, Douglas T

    2012-05-01

    1. In migratory populations, the degree of fidelity and dispersal among seasonal ranges is an important population process with consequences for demography, management, sensitivity to habitat change and adaptation to local environmental conditions. 2. Characterizing patterns of range fidelity in ungulates, however, has remained challenging because of the difficulties of following large numbers of marked individuals across multiple migratory cycles and of identifying the appropriate scale of analysis. 3. We examined fidelity to wet season (i.e. breeding) ranges in a recently declining population of wildebeest Connochaetes taurinus Burchell in northern Tanzania across 3 years. We used computer-assisted photographic identification and capture-recapture to characterize return patterns to three wet season ranges that were ecologically discrete and topographically isolated from one another. 4. Among 2557 uniquely identified adult wildebeest, we observed 150 recaptures across consecutive wet seasons. Between the two migratory subpopulations, the probability of remaining faithful to wet season areas ranged between 0·82 and 1·00. Animals from a non-migratory segment of the population (near Lake Manyara National Park) were rarely observed in other wet season ranges, despite proximity to one of the migratory pathways. 5. We found no effect of sex on an individuals' probability of switching wet season ranges. However, the breeding status of females in year i had a strong influence on patterns of range selection in year i + 1, with surviving breeders over three times as likely to switch ranges as non-breeders. 6. Social-group associations between pairs of recaptured animals were random with respect to an individual's wet season range during the previous or forthcoming wet seasons, suggesting that an individual's herd identity during the dry season does not predict wet season range selection. 7. Examining fidelity and dispersal in terrestrial migrations improves

  12. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm(2) at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications.

  13. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiu-Sheng [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); University of Southern California, Mork Family Department of Chemical Engineering and Materials Science, Los Angeles, CA (United States); Benjauthrit, Vatcharee; Zhou, Qifa; Shung, K.K. [University of Southern California, Department of Biomedical Engineering and NIH Transducer Resource Center, Los Angeles, CA (United States); Wei, Qiang; Huang, Yuhong [Chemat Technology Inc., Northridge, CA (United States)

    2013-05-15

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 {mu}C/cm{sup 2} at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. (orig.)

  14. Visual Impairment

    Science.gov (United States)

    ... What Causes Visual Impairment? People rarely lose their eyesight during their teen years. When they do, it's ... inflammation in the eye. It's often found in poor rural countries that have overcrowded living conditions and ...

  15. Microstructure and Electrical Properties of PMN-PT Thin Films Prepared by Oxygen Plasma Assisted Pulsed Laser Deposition%氧等离子体辅助脉冲激光沉积法制备PMN-PT薄膜的微观结构和电学性能

    Institute of Scientific and Technical Information of China (English)

    何邕; 李效民; 高相东; 冷雪; 王炜

    2011-01-01

    Lead magnesium niobate-lead titanate (PMN-PT) ferroelectric thin films with composition near the morphotropic phase boundary (MPB) were deposited on Si substrate by oxygen plasma assisted pulsed laser deposition (PLD).Highly (001)-oriented PMN-PT thin films with lower oxygen defect and higher crystalline property were obtained.The results show that the microstructure and electrical properties of PMN-PT thin films strongly depend on the partial pressure and the activity of oxygen in the deposition process.With the use of oxygen plasma,the dielectric constant of the PMN-PT thin film is increased from 1484 to 3012,the remnant polarization (2Pr) changes from 18μC/cm2 to 38 μC/cm2.%采用氧等离子体辅助脉冲激光沉积方法(PLD)在硅衬底上,制备出高度(001)取向的钙钛矿相结构钛铌镁酸铅(PMN-PT)薄膜.研究了氧等离子体辅助对PMN-PT薄膜相结构、微观形貌和电学性能的影响.结果表明,通过在薄膜沉积过程中引入高活性的氧等离子,可以有效地提高PMN-PT薄膜的结晶质量和微观结构.未采用氧等离子体辅助PLD方法制备PMN-PT薄膜的介电常数(10 kHz)和剩余极化(2Pr)分别为1484和18 μC/cm2,通过采用氧等离子体辅助,其介电常数和剩余极化分别提高至3012和38 μC/cm2.

  16. Role of heat treatment on the formation of perovskite phase of PMN-PT relaxor ferroelectric thin films derived from inorganic-chelating-gel%热处理对无机盐-螯合-凝胶法制备的PMN-PT弛豫铁电膜钙钛矿相形成的作用

    Institute of Scientific and Technical Information of China (English)

    王歆; 庄志强

    2003-01-01

    研究了PMN-PT薄膜的无机盐-螯合-凝胶法制备,分析和讨论了薄膜热处理工艺对薄膜相结构形成的影响,探讨制备近全钙钛矿相的PMN-PT弛豫铁电薄膜的最佳工艺.

  17. Performance of PIN-PMN-PT Single Crystal Piezoelectric versus PZT8 Piezoceramic Materials in Ultrasonic Transducers

    Science.gov (United States)

    DeAngelis, D. A.; Schulze, G. W.

    The recent advancements in the manufacturing of single crystal PIN-PMN-PT piezoelectric materials now make them a cost-competitive alternative to PZT4 and PZT8 (Navy Types I and III) piezoceramic materials, which have been the workhorse of power ultrasonic applications (e.g., welding, cutting, sonar, etc.) for over 50 years. Although there are great benefits to the use of single crystal materials with respect to high output, as well as added actuating and sensing abilities, many transducer designers are still reluctant to explore these materials due to inadequate design guidelines for substituting the familiar PZT materials; for example, what are the implications of the higher capacitance, sensitivity to chipping/cracks, aging effects, frequency shifts, or how much preload can be used are all common questions. This research is a case study on the performance of identical ultrasonic transducer bodies, used for semiconductor wire bonding, assembled with either PZT8 or PIN-PMN-PT piezo material. The main purpose of the study is to establish rule-of-thumb design guidelines for direct substitution of single crystal materials in existing PZT8 transducer designs, along with a side-by-side performance comparison to highlight benefits. Several metrics are investigated such as impedance, frequency, displacement gain, quality factor and electromechanical coupling factor.

  18. Suppression of polymorphonuclear (PMN) and monocyte-mediated inhibition of Candida albicans growth by delta-9-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Djeu, J.Y.; Parapanios, A.; Halkias, D.; Friedman, H.

    1986-03-05

    This study was an in vitro attempt to identify the effector cells responsible for growth inhibition of the opportunistic fungus, candida albicans, and to determine if THC or another marijuana derivatives, 11-hydroxyTHC, would adversely affect their function. Using a 24h radiolabel assay, the authors found that growth inhibition of C. albicans was primarily mediated by PMN and monocytes that could be isolated normal human peripheral blood. Both effector cell types caused almost complete inhibition of Candida growth at effector/target ratio of 300/1 and inhibition was often still seen at 30/1-. Incubation of PMN, PBL, or monocytes for 1 hr at 37C with THC or 11-hydroxyTHC caused a marked suppression of function in all 3 cell populations. Maximal suppression was obtained with 7.5-10..mu..g/ml of the drugs in medium containing 10% fetal bovine serum (FBS) or with 2-4..mu..g/ml in 1% FBS. These drug concentrations did not affect lymphoid cell viability or candida growth in the absence of lymphoid effector cells. Marijuana derivatives, therefore, are doubly dangerous in that opportunistic fungi such as C. albicans can grow in their presence while the effector cells that control fungal growth are readily inactivated.

  19. The MHz-peaked radio spectrum of the unusual gamma-ray source PMN J1603-4904

    CERN Document Server

    Müller, C; Schulz, R; Coppejans, R; Falcke, H; Intema, H; Kadler, M; Krauß, F; Ojha, R

    2016-01-01

    Context. The majority of bright extragalactic gamma-ray sources are blazars. Only a few radio galaxies have been detected by Fermi/LAT. Recently, the GHz-peaked spectrum source PKS 1718-649 was confirmed to be gamma-ray bright, providing further evidence for the existence of a population of gamma-ray loud, compact radio galaxies. A spectral turnover in the radio spectrum in the MHz to GHz range is a characteristic feature of these objects, which are thought to be young due to their small linear sizes. The multiwavelength properties of the gamma-ray source PMN J1603-4904 suggest that it is a member of this source class. Aims. The known radio spectrum of PMN J1603-4904 can be described by a power law above 1 GHz. Using observations from the Giant Metrewave Radio Telescope (GMRT) at 150, 325, and 610 MHz, we investigate the behaviour of the spectrum at lower frequencies to search for a low-frequency turnover. Methods. Data from the TIFR GMRT Sky Survey (TGSS ADR) catalogue and archival GMRT observations were use...

  20. PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.

    Science.gov (United States)

    Zhou, Qifa; Xu, Xiaochen; Gottlieb, Emanuel J; Sun, Lei; Cannata, Jonathan M; Ameri, Hossein; Humayun, Mark S; Han, Pengdi; Shung, K Kirk

    2007-03-01

    High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.

  1. Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

    Science.gov (United States)

    Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

    2012-11-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors.

  2. Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

    Science.gov (United States)

    Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

    2014-12-01

    Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO3) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10-9 m/V, about 45 times larger than for LiNbO3) but it decreased rapidly below 75 K; at 1.3 K, d15 was only about 8% of its room temperature value.

  3. Probing the Nanodomain Origin and Phase Transition Mechanisms in (UnPoled PMN-PT Single Crystals and Textured Ceramics

    Directory of Open Access Journals (Sweden)

    Aneta Slodczyk

    2010-11-01

    Full Text Available Outstanding electrical properties of solids are often due to the composition heterogeneity and/or the competition between two or more sublattices. This is true for superionic and superprotonic conductors and supraconductors, as well as for many ferroelectric materials. As in PLZT ferroelectric materials, the exceptional ferro- and piezoelectric properties of the PMN-PT ((1−xPbMg1/3Nb2/3O3−xPbTiO3 solid solutions arise from the coexistence of different symmetries with long and short scales in the morphotropic phase boundary (MPB region. This complex physical behavior requires the use of experimental techniques able to probe the local structure at the nanoregion scale. Since both Raman signature and thermal expansion behavior depend on the chemical bond anharmonicity, these techniques are very efficient to detect and then to analyze the subtitle structural modifications with an efficiency comparable to neutron scattering. Using the example of poled (field cooling or room temperature and unpoled PMN-PT single crystal and textured ceramic, we show how the competition between the different sublattices with competing degrees of freedom, namely the Pb-Pb dominated by the Coulombian interactions and those built of covalent bonded entities (NbO6 and TiO6, determine the short range arrangement and the outstanding ferro- and piezoelectric properties.

  4. Multipeak self-biased magnetoelectric coupling characteristics in four-phase Metglas/Terfenol-D/Be-bronze/PMN-PT structure

    Directory of Open Access Journals (Sweden)

    Dongyan Huang

    2015-04-01

    Full Text Available This letter develops a self-biased magnetoelectric (ME structure Metglas/Terfenol-D/Be-bronze/PMN-PT (MTBP consisting of a magnetization-graded Metglas/Terfenol-D layer, a elastic Be-bronze plate, and a piezoelectric 0.67Pb(Mg1/3Nb2/3O3-0.33PbTiO3 (PMN-PT plate. By using the magnetization-graded Metglas/Terfenol-D layer and the elastic Be-bronze plate, multi-peak self-biased ME responses are obtained in MTBP structure. The experimental results show that the MTBP structure with two layers of Metglas foil has maximum zero-biased ME voltage coefficient (MEVC. As frequency increases from 0.5 to 90 kHz, eleven large peaks of MEVC with magnitudes of 0.75-33 V/(cm Oe are observed at zero-biased magnetic field. The results demonstrate that the proposed multi-peak self-biased ME structure may be useful for multifunctional devices such as multi-frequency energy harvesters or low-frequency ac magnetic field sensors.

  5. Multipeak self-biased magnetoelectric coupling characteristics in four-phase Metglas/Terfenol-D/Be-bronze/PMN-PT structure

    Science.gov (United States)

    Huang, Dongyan; Lu, Caijiang; Bing, Han

    2015-04-01

    This letter develops a self-biased magnetoelectric (ME) structure Metglas/Terfenol-D/Be-bronze/PMN-PT (MTBP) consisting of a magnetization-graded Metglas/Terfenol-D layer, a elastic Be-bronze plate, and a piezoelectric 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-PT) plate. By using the magnetization-graded Metglas/Terfenol-D layer and the elastic Be-bronze plate, multi-peak self-biased ME responses are obtained in MTBP structure. The experimental results show that the MTBP structure with two layers of Metglas foil has maximum zero-biased ME voltage coefficient (MEVC). As frequency increases from 0.5 to 90 kHz, eleven large peaks of MEVC with magnitudes of 0.75-33 V/(cm Oe) are observed at zero-biased magnetic field. The results demonstrate that the proposed multi-peak self-biased ME structure may be useful for multifunctional devices such as multi-frequency energy harvesters or low-frequency ac magnetic field sensors.

  6. MIP-1alpha regulates CD4+ T cell chemotaxis and indirectly enhances PMN persistence in Pseudomonas aeruginosa corneal infection.

    Science.gov (United States)

    Kernacki, K A; Barrett, R P; McClellan, S; Hazlett, L D

    2001-12-01

    The role of macrophage inflammatory protein-1alpha (MIP-1alpha) in cell infiltration into Pseudomonas aeruginosa-infected cornea and subsequent disease was examined. Greater amounts of the chemokine (protein and mRNA) were found in the infected cornea of susceptible B6 ("cornea perforates") versus resistant BALB/c ("cornea heals") mice from 1 to 5 days postinfection. Treatment of BALB/c mice with recombinant (r) MIP-1alpha exacerbated disease and was associated with an increased number of neutrophils (PMNs) in the cornea. Treatment of BALB/c mice with rMIP-1alpha also induced recruitment of activated CD4+ T cells into the affected cornea, converting resistant to susceptible mice. Depleting CD4+ T cells in r-treated BALB/c mice significantly decreased PMNs in cornea tissue, suggesting that T cells regulate persistence of PMNs at this site. In B6 mice, administration of neutralizing MIP-1alpha polyclonal antibody also significantly reduced PMN numbers and pathology. Collectively, evidence is provided that MIP-1alpha directly contributed to CD4+ T cell recruitment and indirectly to PMN persistence in the infected cornea.

  7. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R. /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E. /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle; Caliandro, G.A.; /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /NASA, Goddard /NASA, Goddard /CSST, Baltimore /SISSA, Trieste /Naval Research Lab, Wash., D.C. /George Mason U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Garching, Max Planck Inst., MPE /Stockholm U. /Stockholm U., OKC /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /ASDC, Frascati /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Ecole Polytechnique /Brera Observ. /INFN, Trieste /Bonn, Max Planck Inst., Radioastron. /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2012-03-29

    Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  8. Catecholamine stress alters neutrophil trafficking and impairs wound healing by β2-adrenergic receptor-mediated upregulation of IL-6.

    Science.gov (United States)

    Kim, Min-Ho; Gorouhi, Farzam; Ramirez, Sandra; Granick, Jennifer L; Byrne, Barbara A; Soulika, Athena M; Simon, Scott I; Isseroff, R Rivkah

    2014-03-01

    Stress-induced hormones can alter the inflammatory response to tissue injury; however, the precise mechanism by which epinephrine influences inflammatory response and wound healing is not well defined. Here we demonstrate that epinephrine alters the neutrophil (polymorphonuclear leukocyte (PMN))-dependent inflammatory response to a cutaneous wound. Using noninvasive real-time imaging of genetically tagged PMNs in a murine skin wound, chronic, epinephrine-mediated stress was modeled by sustained delivery of epinephrine. Prolonged systemic exposure of epinephrine resulted in persistent PMN trafficking to the wound site via an IL-6-mediated mechanism, and this in turn impaired wound repair. Further, we demonstrate that β2-adrenergic receptor-dependent activation of proinflammatory macrophages is critical for epinephrine-mediated IL-6 production. This study expands our current understanding of stress hormone-mediated impairment of wound healing and provides an important mechanistic link to explain how epinephrine stress exacerbates inflammation via increased number and lifetime of PMNs.

  9. Giant electric field control of magnetism and narrow ferromagnetic resonance linewidth in FeCoSiB/Si/SiO2/PMN-PT multiferroic heterostructures

    Science.gov (United States)

    Gao, Y.; Wang, X.; Xie, L.; Hu, Z.; Lin, H.; Zhou, Z.; Nan, T.; Yang, X.; Howe, B. M.; Jones, J. G.; Brown, G. J.; Sun, N. X.

    2016-06-01

    It has been challenging to achieve combined strong magnetoelectric coupling and narrow ferromagnetic resonance (FMR) linewidth in multiferroic heterostructures. Electric field induced large effective field of 175 Oe and narrow FMR linewidth of 40 Oe were observed in FeCoSiB/Si/SiO2/PMN-PT heterostructures with substrate clamping effect minimized through removing the Si substrate. As a comparison, FeCoSiB/PMN-PT heterostructures with FeCoSiB film directly deposited on PMN-PT showed a comparable voltage induced effective magnetic field but a significantly larger FMR linewidth of 283 Oe. These multiferroic heterostructures exhibiting combined giant magnetoelectric coupling and narrow ferromagnetic resonance linewidth offer great opportunities for integrated voltage tunable RF magnetic devices.

  10. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure.

    Science.gov (United States)

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-07-15

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications.

  11. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure

    Science.gov (United States)

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-07-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications.

  12. Full annual cycle climate change vulnerability assessment for migratory birds

    Science.gov (United States)

    Culp, Leah A.; Cohen, Emily B.; Scarpignato, Amy L.; Thogmartin, Wayne E.; Marra, Peter P.

    2017-01-01

    Climate change is a serious challenge faced by all plant and animal species. Climate change vulnerability assessments (CCVAs) are one method to assess risk and are increasingly used as a tool to inform management plans. Migratory animals move across regions and continents during their annual cycles where they are exposed to diverse climatic conditions. Climate change during any period and in any region of the annual cycle could influence survival, reproduction, or the cues used to optimize timing of migration. Therefore, CCVAs for migratory animals best estimate risk when they include climate exposure during the entire annual cycle. We developed a CCVA incorporating the full annual cycle and applied this method to 46 species of migratory birds breeding in the Upper Midwest and Great Lakes (UMGL) region of the United States. Our methodology included background risk, climate change exposure × climate sensitivity, adaptive capacity to climate change, and indirect effects of climate change. We compiled information about migratory connectivity between breeding and stationary non-breeding areas using literature searches and U.S. Geological Survey banding and re-encounter data. Climate change exposure (temperature and moisture) was assessed using UMGL breeding season climate and winter climate from non-breeding regions for each species. Where possible, we focused on non-breeding regions known to be linked through migratory connectivity. We ranked 10 species as highly vulnerable to climate change and two as having low vulnerability. The remaining 34 species were ranked as moderately vulnerable. In general, including non-breeding data provided more robust results that were highly individualistic by species. Two species were found to be highly vulnerable throughout their annual cycle. Projected drying will have the greatest effect during the non-breeding season for species overwintering in Mexico and the Caribbean. Projected temperature increases will have the greatest

  13. Quantifying variation in migratory strategies using ring-recoveries

    Directory of Open Access Journals (Sweden)

    Siriwardena, G. M.

    2004-06-01

    Full Text Available Bird populations have traditionally been labelled as “migrant” or “resident” on the basis of field observations and qualitative interpretations of patterns of ring–recoveries. However, even such a non–systematic approach has identified many intermediate species where only part of the population migrates (partial migrants or where different components of the population migrate to different extents (differential migrants. A method that would allow a quantitative definition of migratory tendency to be derived for many species would facilitate investigations into the ecological causes and life–history consequences of migratory behaviour. Species or populations could then be placed objectively into the continuum between true residency and an obligate, long–distance migratory habit. We present a novel method for the analysis of ring–recovery data sets that produces just such a quantitative index of migratory tendency for British birds, developed as part of the BTO’s Migration Atlas project (Wernham et al., 2002. The method uses distributions of ringing–to–recovery distances to classify individual species’ patterns of movement relative to those of other species. The areas between species’ cumulative distance distributions are treated as inter–species dissimilarities and a one–dimensional map is then constructed using multi–dimensional scaling. We have used the method in example analyses to show how it can be used to investigate the factors that affect the migratory strategies that species adopt, such as body size, territoriality and distribution, and in studies of their consequences for demographic parameters such as annual survival and the timing of breeding. We have also conducted initial analyses to show how temporal changes in the indices could reveal otherwise unmeasured population consequences of environmental change and thus have an important application in conservation science. Finally, we discuss how our

  14. In situ detection of Bacillus anthracis spores using fully submersible, self-exciting, self-sensing PMN-PT/Sn piezoelectric microcantilevers.

    Science.gov (United States)

    McGovern, John-Paul; Shih, Wan Y; Shih, Wei-Heng

    2007-08-01

    In this study, we have demonstrated in situ, all-electrical detection of Bacillus anthracis (BA) spores using lead magnesium niobate-lead titanate/tin (PMN-PT/Sn) piezoelectric microcantilever sensors (PEMS) fabricated from PMN-PT freestanding films and electrically insulated with methyltrimethoxysilane (MTMS) coatings on the tin surface. Antibody specific to BA spore surface antigen was immobilized on the platinum electrode of the PMN-PT layer. In phosphate-buffered saline (PBS) solution, the PMN-PT/Sn PEMS exhibited quality (Q) values ranging from 50 to 75. The detection was carried out in a closed-loop flow cell with a liquid volume of 0.8 ml and a flow rate of 1 ml min(-1). It was shown that one sensor, "PEMS-A" (500 microm long, 800 microm wide, with a 22 microm thick PMN-PT layer, a 20 microm thick tin layer and a 1 +/- 0.5 x 10(-12) g Hz(-1) mass detection sensitivity) exhibited resonance frequency shifts of 2100 +/- 200, 1100 +/- 100 and 700 +/- 100 Hz at concentrations of 20,000, 2000, and 200 spores ml(-1) or 16,000, 1600, and 160 total spores, respectively. Additionally, "PEMS-B" (350 microm long, 800 microm wide, with an 8 microm thick PMN-PT layer, a 6 microm thick tin layer and a 2 +/- 1 x 10(-13) g Hz(-1) mass detection sensitivity) exhibited resonance frequency shifts of 2400 +/- 200, 1500 +/- 200, 500 +/- 150 and 200 +/- 100 Hz at concentrations of 20,000, 2000, 100, and 45 spores ml(-1) or 16,000, 1600, 80, and 36 total spores, respectively.

  15. Piezo-phototronic effect-induced dual-mode light and ultrasound emissions from ZnS:Mn/PMN-PT thin-film structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yang; Gao, Guanyin; Chan, Helen L.W.; Dai, Jiyan; Wang, Yu.; Hao, Jianhua [Department of Applied Physics and Materials Research Center, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2012-04-03

    Electric-field-controllable luminescence of a ZnS:Mn/PMN-PT system is demonstrated. The light-emission of ZnS:Mn is caused by the piezoelectric potential, resulting from the converse piezoelectric effect of the PMN-PT substrate. Simultaneous generation of light and ultrasound waves is observed in this single system, which offers great potential to develop a dual-modal source combing light and ultrasonic waves for various applications. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Possibly drug-induced palpable migratory arciform erythema*

    Science.gov (United States)

    Dantas, Fernando Luiz Teixeira; Valente, Neusa Yuriko Sakai; Veronez, Isis Suga; Kakizaki, Priscila; Leitão, Juliana Ribeiro; Fraga, Rafael Cavanellas

    2015-01-01

    Palpable migratory arciform erythema is an entity of unknown etiology, with few published cases in the literature. The clinical and histopathological features of this disease are difficult to be distinguished from those of Jessner’s lymphocytic infiltration of the skin, lupus erythematous tumidus and the deep erythema annulare centrifugum. We describe here the first two Brazilian cases of palpable migratory arciform erythema. The patients presented with infiltrated annular plaques and erythematous arcs without scales. These showed centrifugal growth before disappearing without scarring or residual lesions after a few days. They had a chronic course with repeated episodes for years. In addition, these cases provide evidence of a drug-induced etiology. PMID:26312680

  17. Regional migratory osteoporosis: a review illustrated by five cases

    Energy Technology Data Exchange (ETDEWEB)

    Toms, A.P. [Department of Radiology, Norfolk and Norwich University Hospital, Norwich (United Kingdom)]. E-mail: andoni.toms@nnuh.nhs.uk; Marshall, T.J. [Department of Radiology, Norfolk and Norwich University Hospital, Norwich (United Kingdom); Becker, E. [Department of Radiology, Toronto General Hospital, Toronto (Canada); Donell, S.T. [Department of Orthopaedic Surgery, Norfolk and Norwich University Hospital, Norwich (United Kingdom); Lobo-Mueller, E.M. [Department of MRI, Felicio Rocho Hospital, Belo Horizonte-MG (Brazil); Barker, T. [Department of Pathology, Norfolk and Norwich University Hospital, Norwich (United Kingdom)

    2005-04-01

    Regional migratory osteoporosis is an uncommon self-limiting disease characterized by an arthralgia which migrates between the weight-bearing joints of the lower limb. The radiological features of the disease obtained by conventional radiography, CT, MRI and radionuclide scintigraphy are illustrated by means of five case reports. These range from the most common presentation of sequential, proximal to distal spread in the lower limb to the rare intra-articular form, and disease involving the axial skeleton is also recognized. Clinical and radiographical features often overlap with those of diseases such as transient osteoporosis of the hip and transient bone marrow oedema syndrome, which is reflected in confusing terminology. Histological sampling is usually unnecessary; the radiological features are characteristic and the histological findings are not specific. Regional migratory osteoporosis is associated with systemic osteoporosis. This association is probably under-recognized, and has implications for the pathophysiology of the disease and for treatment.

  18. PMN-PT弛豫铁电粉体的溶胶-凝胶法制备及其性质%Preparation and Characterization of PMN-PT Relax Ferroelectric Powders by Sol-Gel Method

    Institute of Scientific and Technical Information of China (English)

    王歆; 庄志强; 齐雪君

    2002-01-01

    以无机盐或氧化物Nb2O5、MgO、TiCl4和Pb(Ac)2@3H2O为原材料,柠檬酸和EDTA为复合螯合剂,乙二醇为溶剂,分别制备Nb、Mg-Nb、Ti和Pb的有机化合物前驱液,采用溶胶-凝胶工艺制备PMN-PT弛豫铁电陶瓷粉体及其烧结体.讨论了制备工艺和螯合剂等对金属有机化合物溶液的性质、材料物相形成和介电性能的影响.

  19. PMN-PT单晶与陶瓷在性能及相变方面的特点%Characters of Piezoelectricity and Phase Transition of PMN-PT Single Crystals and Ceramics

    Institute of Scientific and Technical Information of China (English)

    王评初; 罗豪; 李东林; 潘晓明; 陈辛尘; 殷之文

    2001-01-01

    着重介绍了用Bridgman方法生长的(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-PT)固溶体单晶在介电、压电、热释电性能及相变方面的一些特点:①异常高的压电常数d33(高达3000pC/N以上),耦合系数kt(在0.6以上),k33(达0.90),高的介电常数ε(高达5000甚至更高),低的Qm值(约60),热释电系数也较高. ②强烈的各向异性. ③随着PT含量的增加,系统的弛豫行为逐渐减弱,在x0.33时, 材料在室温下成为正常铁电体,但PE--FE相变并非正常铁电相变,表现为在T>Tm时,ε~T关系不遵守居里-外斯定律,而是遵守Smolenskii 的关系. 该相变也明显地与弥散相变不同. 这种行为可用无规场的观点加以解释. 对PMN-PT陶瓷,其压电性能与最好的软性PZT相似,而ε和k31略大.%Some special features in dielectric, piezoelectric properties and phase transition behavior of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) (x=0.24, 0.3, 0.33 and 0.35) single crystals grown by Bridgman method were outlined: 1) Extremely high piezoelectric constant d33 (up to 3000 pC/N) and coupling factors k33 and kt (up to 0.94 and 0.62 respectively), low mechanical factor of merit (Qm60), large dielectric constant (5000). 2) Strong orientation dependence of piezoelectric properties. 3) with increasing PT content, the system becomes less relaxational, but at least upto x=0.35, the system still partly exhibites relaxor feature: for x=0.33 and 0.35. ~T curves look sharp enough to show a normal ferroelectric like feature, however when T>Tm the ε~T relation does not obey Curie-Weiss law, but follows Smolenskii's relation.The piezoelectric properties of PMN-PT ceramics are similar to PZT-5H, but with higher and k31.

  20. Hearing Impairments

    Science.gov (United States)

    Cavender, Anna; Ladner, Richard E.

    For many people with hearing impairments, the degree of hearing loss is only a small aspect of their disability and does not necessarily determine the types of accessibility solutions or accommodations that may be required. For some people, the ability to adjust the audio volume may be sufficient. For others, translation to a signed language may be more appropriate. For still others, access to text alternatives may be the best solution. Because of these differences, it is important for researchers in Web accessibility to understand that people with hearing impairments may have very different cultural-linguistic traditions and personal backgrounds.

  1. Migratory bats respond to artificial green light with positive phototaxis.

    Science.gov (United States)

    Voigt, Christian C; Roeleke, Manuel; Marggraf, Lara; Pētersons, Gunārs; Voigt-Heucke, Silke L

    2017-01-01

    Artificial light at night is spreading worldwide at unprecedented rates, exposing strictly nocturnal animals such as bats to a novel anthropogenic stressor. Previous studies about the effect of artificial light on bats focused almost exclusively on non-migratory species, yet migratory animals such as birds are known to be largely affected by light pollution. Thus, we conducted a field experiment to evaluate if bat migration is affected by artificial light at night. In late summer, we presented artificial green light of 520 nm wavelength to bats that were migrating south along the shoreline of the Baltic Sea. Using a light on-off treatment, we observed that the activity of Pipistrellus nathusii and P. pygmaeus, the two most abundant migratory species at our site, increased by more than 50% in the light-on compared to the light-off treatment. We observed an increased number of feeding buzzes during the light-on compared to the light-off treatment for P. nathusii. However, feeding activity was low in general and did not increase disproportionately during the light-on treatment in relation to the overall echolocation call activity of bats. Further, P. nathusii were attracted towards the green light at a distance of about 23 m, which is way beyond the echolocation detection range for insects of Nathusius' bats. We therefore infer that migratory bats were not attracted to artificial green light because of high insect densities, but instead by positive phototaxis. We conclude that artificial light at night may potentially impact bat migration in a yet unrecognized way.

  2. Norepinephrine inhibits the migratory activity of pancreatic cancer cells.

    Science.gov (United States)

    Stock, Anna-Maria; Powe, Desmond G; Hahn, Stephan A; Troost, Gabriele; Niggemann, Bernd; Zänker, Kurt S; Entschladen, Frank

    2013-07-15

    We have shown previously that norepinephrine induces migratory activity of tumour cells from breast, colon and prostate tissue via activation of beta-2 adrenergic receptors. Consequently, this effect can be inhibited pharmacologically by clinically established beta-blockers. Tumour cell migration is a prerequisite for metastasis formation, and accordingly we and others have shown that breast cancer patients, which take beta-blockers due to hypertension, have reduced metastasis formation and increased survival probability as compared to patients without hypertension or using other anti-hypertensive medication. Unlike the aforementioned tumour cells, pancreatic cancer cells show a reduced migratory activity upon norepinephrine treatment. By means of our three-dimensional, collagen-based cell migration assay, we have investigated the signal transduction pathways involved in this phenomenon. We have found that this conflicting effect of norepinephrine on pancreatic cancer cells is due to an imbalanced activation of the two pathways that usually mediate a pro-migratory effect of norepinephrine in other tumour cell types. Firstly, the inhibitory effect results from activation of a pathway which causes a strong increase of the secondary cell signalling molecule, cAMP. In addition, activation of phospholipase C gamma and the downstream protein kinase C alpha were shown to be already activated in pancreatic cancer cells and cannot be further activated by norepinephrine. We hypothesize that this constitutive activation of the phospholipase C gamma pathway is due to a cross-talk with receptor tyrosine kinase signalling, and this might also deliver an explanation for the unusual high spontaneous migratory activity of pancreatic cancer cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Necrolytic Migratory Erythema as the First Manifestation of Glucagonoma

    Directory of Open Access Journals (Sweden)

    Abolfazl Afsharfard

    2012-01-01

    Full Text Available Necrolytic migratory erythma (NME as a rare skin disorder that can affected Perineum, distal extremities, lower abdomen and face are the most commonly affected sites.It can be as a part of Glucagonoma syndrome that is defined as an association of glucagonoma with NME, hyperglucagonemia, glucose intolerance, anemia and weight loss. Here, Authors describe a woman admitted to the dermatology ward with NME which was later found to be associated with glucagonoma and multiple hepatic lesions.

  4. All Vision Impairment

    Science.gov (United States)

    ... Home > Statistics and Data > All Vision Impairment All Vision Impairment Vision Impairment Defined Vision impairment is defined as the ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Vision Impairment by Age and Race/Ethnicity Table for ...

  5. Feeding impairs chill coma recovery in the migratory locust (Locusta migratoria).

    Science.gov (United States)

    Andersen, Jonas Lembcke; Findsen, Anders; Overgaard, Johannes

    2013-10-01

    Low temperature causes loss of neuromuscular function in a wide range of insects, such that the animals enter a state known as chill coma. The ability to recover from chill coma (chill coma recovery time) is often a popular phenotype to characterise chill tolerance in insects. Chill coma in insects has been shown to be associated with a decrease in haemolymph volume and a marked increase in [K(+)], causing dissipation of K(+) equilibrium potential and resting membrane potential. High potassium diet (wheat) has also previously been shown to increase haemolymph [K(+)] in Locusta migratoria leading to sluggish behaviour. The present study combined these two independent stressors of ion and water homeostasis, in order to investigate the role of K(+)- and water-balance during recovery from chill coma, in the chill sensitive insect L. migratoria. We confirmed that cold shock elicits a fast increase in haemolymph [K(+)] which is likely caused by a water shift from the haemolymph to the muscles and other tissues. Recovery of haemolymph [K(+)] is however not only reliant on recovery of haemolymph volume, as the recovery of water and K(+) is decoupled. Chill coma recovery time, after 2h at -4 °C, differed significantly between fasted animals and those fed on high K(+) diet. This difference was not associated with an increased disturbance of haemolymph [K(+)] in the fed animals, instead it was associated with a slowed recovery of muscle [K(+)], muslce water, haemolymph [Na(+)] and K(+)equilibrium potential in the fed animals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure

    Science.gov (United States)

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X.; Yang, Xi; Liu, Ming

    2016-02-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also “store” the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities.

  7. Magnetic microscopy and simulation of strain-mediated control of magnetization in Ni/PMN-PT nanostructures.

    Science.gov (United States)

    Gilbert, Ian; Chavez, Andres C; Pierce, Daniel T; Unguris, John; Sun, Wei-Yang; Liang, Cheng-Yen; Carman, Gregory P

    2016-10-01

    Strain-mediated thin film multiferroics comprising piezoelectric/ferromagnetic heterostructures enable the electrical manipulation of magnetization with much greater efficiency than other methods; however, the investigation of nanostructures fabricated from these materials is limited. Here we characterize ferromagnetic Ni nanostructures grown on a ferroelectric PMN-PT substrate using scanning electron microscopy with polarization analysis (SEMPA) and micromagnetic simulations. The magnetization of the Ni nanostructures can be controlled with a combination of sample geometry and applied electric field, which strains the ferroelectric substrate and changes the magnetization via magnetoelastic coupling. We evaluate two types of simulations of ferromagnetic nanostructures on strained ferroelectric substrates: conventional micromagnetic simulations including a simple uniaxial strain, and coupled micromagnetic-elastodynamic simulations. Both simulations qualitatively capture the response of the magnetization changes produced by the applied strain, with the coupled solution providing more accurate representation.

  8. Tunable fringe magnetic fields induced by converse magnetoelectric coupling in a FeGa/PMN-PT multiferroic heterostructure

    Science.gov (United States)

    Fitchorov, Trifon; Chen, Yajie; Hu, Bolin; Gillette, Scott M.; Geiler, Anton; Vittoria, Carmine; Harris, Vincent G.

    2011-12-01

    The fringe magnetic field, induced by magnetoelectric coupling in a bilayer Fe-Ga/Pb(Mg1/3Nb2/3)O3_PbTiO3 (PMN-PT) multifunctional composite, was investigated. The induced external field is characterized as having a butterfly hysteresis loop when tuned by an applied electric field. A tuning coefficient of the electrically induced fringe magnetic field is derived from the piezoelectric and magnetostrictive properties of the composite. A measured maximum tuning coefficient, 4.5 Oe/(kV cm-1), is found to agree well with theoretical prediction. This work establishes a foundation in the design of transducers based on the magnetoelectric effect.

  9. PMN-PZN-PT铁电陶瓷的准同型相界及电学性能

    Institute of Scientific and Technical Information of China (English)

    陈焱; 张孝文

    2009-01-01

    基于准同型相界(morphotropic phase boundary,MPB)线性组合规律,研究Pb(Mg1/3Nb2/3)O3-Pb(Zn1/3Nb2/3)O3-PbTiO3(PMN-PZN-PT)三元系的MPB区域,并探求电学性能优越的组分。实验选取(1-x)(0.67PMN-0.33PT)-x(0.91PZN-0.09PT)系列中x=0~0.85的8个实验点;为减少焦绿石相的生成,陶瓷试样用铌铁矿预产物法合成,最终在1120~1160℃烧成。X射线衍射分析表明该系列试样均为钙钛矿结构,且处于四方与菱方两相共存态,验证了两个子二元系MPB组分的连线均为该三元系的MPB区域。少量的PZN-PT取代PMN—PT可以提高该三元系的电学性能;在x=0.1的组分获得该系列的最优性能:极值介电常数εm.1kHz=28030,剩余极化强度Pr=32.5μC/cm2,压电系数d33=545pC/N。

  10. Golgi fragmentation in pmn mice is due to a defective ARF1/TBCE cross-talk that coordinates COPI vesicle formation and tubulin polymerization

    NARCIS (Netherlands)

    Bellouze, Sarah; Schäfer, Michael K; Buttigieg, Dorothée; Baillat, Gilbert; Rabouille, Catherine; Haase, Georg

    2014-01-01

    Golgi fragmentation is an early hallmark of many neurodegenerative diseases but its pathophysiological relevance and molecular mechanisms are unclear. We here demonstrate severe and progressive Golgi fragmentation in motor neurons of progressive motor neuronopathy (pmn) mice due to loss of the Golgi

  11. Migratory restlessness in captive individuals predicts actual departure in the wild

    OpenAIRE

    Eikenaar, Cas; Klinner, Thomas; Szostek, K. Lesley; Bairlein, Franz

    2014-01-01

    In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such ‘migratory restlessness’ has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific trait...

  12. 高压退火对0.65PMN-0.35PT 薄膜结构、形貌及电学性能的影响*%Effects of high pressure annealing technique on the structure, morphology and electric properties of 0.65PMN-0.35PT thin films∗

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      利用射频磁控溅射技术在 LaNiO3/SiO2/Si(100)基底上制备了厚度约为250 nm 的0.65PMN-0.35PT(PMN-PT)薄膜.研究高压氧氛围退火方式对 PMN-PT 薄膜晶体结构、形貌以及电学性能的影响.经过 XRD 测试发现,在高压氧气氛围中,温度为400◦C 下退火后的 PMN-PT 薄膜具有纯的钙钛矿相结构,具有完全的(100)择优取向,且衍射峰尖锐,表明经过高压退火后的薄膜结晶极为充分. SEM 表面形貌测试结果显示,经高压退火处理的 PMN-PT 薄膜表面呈现出棒状或泡状的形貌.铁电性能测试表明:氧气氛围压强4 MPa,退火时间4h 的 PMN-PT 薄膜样品具有较好的铁电性能,其剩余极化强度 Pr 达到10.544µC/cm2,且电滞回线形状较好,但漏电流较大,这可能是由于其微结构所导致.同时介电测试发现: PMN-PT 薄膜样品具有极好的介电性能,其在1 kHz 下测试的介电常数εr 达到913,介电损耗 tgδ较小,仅为0.065.%Thin films of 0.65PMN-0.35PT PMN=Pb (Mg1/3Nb2/3)O3 and PT=PbTiO3 with a thickness about 250 nm were prepared on LaNiO3/SiO2/Si substrates by radio frequency magnetron sputtering. The films were annealed using high pressure annealing (HPA) technique in oxygen atmosphere. Effect of HPA on the crystal structure, morphology and electrical properties of the films was studied. XRD patterns of the films indicated that PMN-PT films treated by HPA in oxygen atmosphere (annealing temperature 400 ◦C) showed a pure perovskite phase, with highly (100) preferred orientation. The strong and sharp diffraction peak showed the better crystallization of PMN-PT thin films after HPA. SEM observations showed that a rod or bubble morphology was present on the films surface. Ferroelectric properties tests showed that the PMN-PT film annealed in oxygen atmosphere at a pressure of 4 MPa, and annealing time of 4 h had good ferroelectric properties, in which the remanent polarization (Pr) could reach 10.544 uC/cm2. The shape

  13. Roach partial migration-causes and consequences of individual variation in migratory timing

    Directory of Open Access Journals (Sweden)

    Kaj Hulthén

    2015-12-01

    Full Text Available Patterns of animal migration often vary dramatically within species. Understanding the mechanisms, which shape this variation, is important due to the powerful impacts migratory species can have upon ecosystem processes. Migratory timing is thought to be especially critical for survival and reproductive success and variance in migratory timing has been shown to differ between individuals and seasons across a wide range of taxa. Here we investigate the ecological and evolutionary mechanisms, which drive this commonly observed phenomenon. By individual based tracking of roach, a common migratory freshwater fish, in European lakes over multiple migration periods we obtained highly detailed (year-round scheduling and repeat journeys information on the migratory patterns of both populations and individuals. Our analyses show that individuals exhibit strong site fidelity and consistency in timing if migration. Furthermore, variation in migratory timing differed seasonally with less variance and more pronounced migration synchrony in spring as compared to autumn. We then show that at an individual level, survival is strongly linked with the timing of spring migration, but not to autumn migration. Hence, natural selection acts to reduce variance in spring migratory timing via survival costs to individuals that deviate from an optimal migratory schedule in spring but not autumn. Our data provides a detailed insight from a longitudinally monitored, wild population into intrapopulation variability in migration strategies and fitness correlates of individual variation in migratory timing.

  14. Fabrication and characterization of ternary compound PMnN-PZT thin films on silicon substrates%硅基三元系PMnN—PZT铁电薄膜制备与研究

    Institute of Scientific and Technical Information of China (English)

    张涛; 张淑仪; 李敏; 周胜男; 孙斌

    2012-01-01

    利用磁控溅射方法在单晶Si基底上沉积三元系铁电薄膜6%PMnN-94%5PZT(6%Pb(Mn1/3,Nb2/3)O3—94%Pb(Zr0.52,Ti0.48)O3),采用淬火方法对薄膜进行处理,以促进薄膜钙钛矿结构形成。同时,在相同条件下制备非掺杂PZT(52/48)薄膜以对比薄膜掺杂效果。运用X射线衍射(XRD)技术分析薄膜晶向及晶体结构,运用SawyerTower电路测试薄膜铁电性能,运用激光测振仪测试薄膜的压电系数。实验结果表明,所沉积薄膜为多晶钙钛矿结构铁电薄膜,薄膜铁电剩余极化Pr=23.7μC/cm2,饱和极化Ps=40μC/cm2,矫顽场电压2Ec=139kV/cm,横向压电系数e11=-13.2C/m2,薄膜的铁电及压电性能优良。%The ternary compound ferroelectric thin films, 6% Pb ( Mnl/3 , Nb2/3 ) O3-94 % Pb (Zr0.52, Ti0.48 ) 03, were deposited on the silicon substrates by the magnetron sputtering method, and the quench method was adopted for the post heat treatment for the perovskite phase. Besides, the non-doped PZT(52/48) thin films were also fab- ricated for comparisons with the same sputtering method. The X-ray diffraction was used to characterize the crystal structures of thin films, and the Sawyer Tower circuit was used to measure the ferroelectricity, and the laser vibration measurement system was used to measure the transverse piezoelectric coefficient of thin films. The results show that the PMnN-PZT thin films own perovskite structures, and the remnant polarization Pr = 23. 7μC/cm2 , the saturation polarization Ps=40μC/cm2 and the coercive electric field 2Ec=139kV/cm, and the transverse piezoelectric coefficient c31 = - 13. 2C/m2 , which identifies that the PMnN-PZT thin films own excellent ferroeleetricity and piezoelectricity.

  15. Key Features of Intertidal Food Webs That Support Migratory Shorebirds

    Science.gov (United States)

    Saint-Béat, Blanche; Dupuy, Christine; Bocher, Pierrick; Chalumeau, Julien; De Crignis, Margot; Fontaine, Camille; Guizien, Katell; Lavaud, Johann; Lefebvre, Sébastien; Montanié, Hélène; Mouget, Jean-Luc; Orvain, Francis; Pascal, Pierre-Yves; Quaintenne, Gwenaël; Radenac, Gilles; Richard, Pierre; Robin, Frédéric; Vézina, Alain F.; Niquil, Nathalie

    2013-01-01

    The migratory shorebirds of the East Atlantic flyway land in huge numbers during a migratory stopover or wintering on the French Atlantic coast. The Brouage bare mudflat (Marennes-Oléron Bay, NE Atlantic) is one of the major stopover sites in France. The particular structure and function of a food web affects the efficiency of carbon transfer. The structure and functioning of the Brouage food web is crucial for the conservation of species landing within this area because it provides sufficient food, which allows shorebirds to reach the north of Europe where they nest. The aim of this study was to describe and understand which food web characteristics support nutritional needs of birds. Two food-web models were constructed, based on in situ measurements that were made in February 2008 (the presence of birds) and July 2008 (absence of birds). To complete the models, allometric relationships and additional data from the literature were used. The missing flow values of the food web models were estimated by Monte Carlo Markov Chain – Linear Inverse Modelling. The flow solutions obtained were used to calculate the ecological network analysis indices, which estimate the emergent properties of the functioning of a food-web. The total activities of the Brouage ecosystem in February and July are significantly different. The specialisation of the trophic links within the ecosystem does not appear to differ between the two models. In spite of a large export of carbon from the primary producer and detritus in winter, the higher recycling leads to a similar retention of carbon for the two seasons. It can be concluded that in February, the higher activity of the ecosystem coupled with a higher cycling and a mean internal organization, ensure the sufficient feeding of the migratory shorebirds. PMID:24204666

  16. Wetland suitability and connectivity for trans-Saharan migratory waterbirds.

    Science.gov (United States)

    Merken, Ronny; Deboelpaep, Evelien; Teunen, Joachim; Saura, Santiago; Koedam, Nico

    2015-01-01

    To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area) we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica). We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks' overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90-7.36%) and an overall decrease of the network's connectivity (0.65-6.82%). In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland complexes could

  17. Wetland suitability and connectivity for trans-Saharan migratory waterbirds.

    Directory of Open Access Journals (Sweden)

    Ronny Merken

    Full Text Available To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica. We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks' overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90-7.36% and an overall decrease of the network's connectivity (0.65-6.82%. In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland

  18. 电场对[100]cub切型PMN-PT单晶电畴组态的影响%Effects of Electric Field on Domain Configuration in the [100]cub-oriented Crystal of PMN-PT

    Institute of Scientific and Technical Information of China (English)

    惠增哲; 项卓亮; 龙伟; 李晓娟

    2011-01-01

    采用偏光显微镜观察了电场作用下[100]cub切型PMN-PT弛豫铁电单晶电畴组态的变化.结果表明:在正向电场作用下,当电场强度超过2.45 kV/cm时,平行于电场方向小畴条带慢慢消失,当电场强度升高到7.15 kV/cm时,原畴壁逐渐消失,在接近电极附近试样上优先出现了垂直于电场方向的新电畴;在反向电场作用下,电场强度超过2.05 kV/cm时,电畴条带沿电场方向扩展,当电场强度升到7.15 kV/cm时,平行于电场方向电畴消失,而出现许多垂直于电场方向电畴;在交流电场驱动下,电畴以低于50 Hz的频率做周期性振动.%The domain configuration in the [100]cub-oriented crystal of relaxor-ferroelectric PMN-PT was investigated with a polarizing microscope.The results indicated that under the positive DC electric field,the small ribbon-like domains paralleling to the electric field disappeared gradually when the intensity of electric field exceeded 2.45 kV/cm, and the new domains perpendicular to the electric field emerged near the electrode when the intensity of electric field rose to 7.15 kV/cm.Under the negative DC electric field, the ribbon-like domains grew along the electric field when the intensity of electric field exceeded 2.05 kV/cm.When the intensity of electric field reached 7.15 kV/cm,the domains paralleling to the electric field disappeared gradually and the new domains perpendicular to the electric field emerged.Under AC electric field, domains were vibrating with the frequency less than 50 Hz.

  19. The generation of oligodendroglial cells is preserved in the rostral migratory stream during aging

    Directory of Open Access Journals (Sweden)

    Vivian eCapilla-Gonzalez

    2013-09-01

    Full Text Available The subventricular zone (SVZ is the largest source of newly generated cells in the adult mammalian brain. SVZ-derived neuroblasts migrate via the rostral migratory stream (RMS to the olfactory bulb (OB, where they differentiate into mature neurons. Additionally, a small proportion of SVZ-derived cells contribute to the generation of myelinating oligodendrocytes. The production of new cells in the SVZ decreases during aging, affecting the incorporation of new neurons into the OB. However, the age-related changes that occur across the RMS are not fully understood. In this study we evaluate how aging affects the cellular organization of migrating neuroblast chains, the proliferation, and the fate of the newly generated cells in the SVZ-OB system. By using electron microscopy and immunostaining, we found that the RMS path becomes discontinuous and its cytoarchitecture is disorganized in aged mice (24-month-old mice. Subsequently, OB neurogenesis was impaired in the aged brain while the production of oligodendrocytes was not compromised. These findings provide new insight into oligodendrocyte preservation throughout life. Further exploration of this matter could help the development of new strategies to prevent neurological disorders associated with senescence.

  20. Argonaute 1 is indispensable for juvenile hormone mediated oogenesis in the migratory locust, Locusta migratoria.

    Science.gov (United States)

    Song, Jiasheng; Guo, Wei; Jiang, Feng; Kang, Le; Zhou, Shutang

    2013-09-01

    Juvenile hormone (JH) is the primary hormone controlling vitellogenesis and oocyte maturation in the migratory locust Locusta migratoria, an evolutionarily primitive insect species with panoistic ovaries. However, molecular mechanisms of locust oogenesis remain unclear and the role of microRNA (miRNA) in JH mediated locust vitellogenesis and oocyte maturation has not been explored. Using miRNA sequencing and quantification with small RNA libraries derived from fat bodies of JH-deprived versus JH analog-exposed female adult locusts, we have identified 83 JH up-regulated and 60 JH down-regulated miRNAs. QRT-PCR validation has confirmed that transcription of selected miRNAs responded to JH administration and correlated with changes in endogenous hemolymph JH titers. Depletion of Argonaute 1 (Ago1), a key regulator of miRNA biogenesis and function by RNAi in female adult locusts dramatically decreased the expression of vitellogenin (Vg) and severely impaired follicular epithelium development, terminal oocyte maturation and ovarian growth. Our data indicate that Ago1 and Ago1-dependent miRNAs play a crucial role in locust vitellogenesis and egg production.

  1. Preparation and Characterization of Multiferroic La0.7Sr0.3MnO3/PMN-PT Composite Thin Films%多铁性La0.7Sr0.3MnO3/PMN-PT复合薄膜的制备及表征

    Institute of Scientific and Technical Information of China (English)

    苟喜成; 冯明; 刘鑫鑫; 李海波

    2012-01-01

    Multiferroic La0.7Sr0.3MnO3/PMN-PT(LSMO/PMN-PT) Composite films were prepared on Pt/Ti/SiO2/Si substrate via sol-gel spin-coating method.The structure,surface topography,ferroelectric and magnetic properties were characterized by X-ray diffraction(XRD),atomic force microscope(AFM),ferroelectric tester and vibrating sample magnetometer(VSM).The results show that all the XRD peaks corresponding to LSMO and PMN-PT compositional phases,and there exists no chemical reaction or phase diffusion between the LSMO and PMN-PT phases after annealing at 750 ℃.AFM investigation shows that the films have a smooth surface with densely packed uniform grains.The composite thin films exhibit evident ferroelectric and ferromagnetic properties.%采用溶胶-凝胶法在Pt/Ti/SiO2/Si基片上制备了La0.7Sr0.3MnO3/PMN-PT(LSMO/PMN-PT)复合薄膜,利用X射线衍射(XRD)、原子力显微镜(AFM)、铁电性能综合测试仪、振动样品磁强计(VSM)对样品的结构、表面形貌以及铁电性能、磁性进行了分析.结果表明,LSMO/PMN–PT复合薄膜750℃退火处理后,所有X射线衍射峰均为样品特征峰,无扩散现象,没有新相生成;薄膜表面平整、致密、颗粒分布均匀;复合薄膜表现出了明显的铁电和铁磁性能.

  2. Quarterly narrative report : November, December, 1939, January, 1940 for Des Lacs Migratory Waterfowl Refuge, Lostwood Migratory Waterfowl Refuge, & Easement Refuges in District IV

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Des Lacs & Lostwood Migratory Waterfowl Refuge outlines Refuge accomplishments from November 1939 through January of 1940. The report...

  3. In-plane anisotropic effect of magnetoelectric coupled PMN-PT/FePt multiferroic heterostructure: Static and microwave properties

    Directory of Open Access Journals (Sweden)

    Jose M. Vargas

    2014-10-01

    Full Text Available The effects of the electric and magnetic field variation on multiferroic heterostructure were studied in this work. Thin films of polycrystalline Fe50Pt50 (FePt were grown by dc-sputtering on top of the commercial slabs of lead magnesium niobate-lead titanate (PMN-PT. The sample was a (011-cut single crystal and had one side polished. In this condition, the PMN-PT/FePt operates in the L-T (longitudinal magnetized-transverse polarized mode. A FePt thin film of 20 nm was used in this study to avoid the characteristic broad microwave absorption line associated with these films above thicknesses of 40 nm. For the in-plane easy magnetization axis (01-1, a microwave magnetoelectric (ME coupling of 28 Oe cm kV −1 was estimated, whereas a value of 42 Oe cm kV −1 was obtained through the hard magnetization axis (100. Insight into the effects of the in-plane strain anisotropy on the ME coupling is obtained from the dc-magnetization loops. It was observed that the trend was opposite along the easy and hard magnetic directions. In particular, along the easy-magnetic axis (01-1, a square and narrow loop with a factor of Mr/MS of 0.96 was measured at 10 kV/cm. Along the hard-magnetic axis, a factor of 0.16 at 10 kV/cm was obtained. Using electric tuning via microwave absorption at X-band (9.78 GHz, we observe completely different trends along the easy and hard magnetic directions; Multiple absorption lines along the latter axis compared to a single and narrower absorption line along the former. In spite of its intrinsic complexity, we propose a model which gives good agreement both for static and microwave properties. These observations are of fundamental interest for future ME microwave components, such as filters, phase-shifters, and resonators.

  4. Fatalities at wind turbines may threaten population viability of a migratory bat

    Science.gov (United States)

    W.F. Frick; E.F. Baerwald; J.F. Pollock; R.M.R. Barclay; J.A. Szymanski; Ted Weller; A.L. Russell; Susan Loeb; R.A. Medellin; L.P. McGuire

    2017-01-01

    Large numbers of migratory bats are killed every year at wind energy facilities. However, population-level impacts are unknown as we lack basic demographic information about these species. We investigated whether fatalities at wind turbines could impact population viability of migratory bats, focusing on the hoary bat (Lasiurus cinereus),...

  5. "Migratory Literature": A "Third Place" for Intercultural Teaching and Learning of Chinese as a Second Language?

    Science.gov (United States)

    Hay, Trevor; Wang, Yongyang

    2010-01-01

    This paper, drawing upon multidisciplinary studies such as critical and cultural studies, literary criticism, intercultural communication and second language acquisition, suggests a specific literary genre--"migratory literature"--to support intercultural competence for learners of Chinese. We begin by elucidating key terms--"migratory,"…

  6. Migratory Recovery from Infection as a Selective Pressure for the Evolution of Migration.

    Science.gov (United States)

    Shaw, Allison K; Binning, Sandra A

    2016-04-01

    Migration, a widespread animal behavior, can influence how individuals acquire and transmit pathogens. Past work has demonstrated that migration can reduce the costs of pathogen or parasite infection through two processes: migratory escape from infected areas or individuals and migratory culling of infected individuals. Here, we propose a third process: migratory recovery, where infected individuals lose their parasites and recover from infection during migration. Recovery can occur when parasites and/or their intermediate hosts cannot support changes in the migratory host's internal or external environment during migration. Thus, parasite mortality increases with migration. Although migratory recovery is likely widespread across species, it remains challenging to empirically test it as a selective force promoting migration. We develop a model and determine the conditions under which migratory recovery theoretically favors the evolution of migration. We show that incorporating migratory recovery into a model of migratory escape increases the range of biologically realistic conditions favoring migration and leads to scenarios where partial migration can evolve. Motivated by empirical estimates of infection costs, our model shows how recovery from infection could drive the evolution of migration. We suggest a number of future directions for both theoretical and empirical research in this area.

  7. 75 FR 34758 - Proposed Information Collection; OMB Control Number 1018-0023; Migratory Bird Surveys

    Science.gov (United States)

    2010-06-18

    ... Fish and Wildlife Service Proposed Information Collection; OMB Control Number 1018-0023; Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for comments. SUMMARY: We... regulations as needed. II. Data OMB Control Number: 1018-0023. Title: Migratory Bird Surveys. Service Form...

  8. 78 FR 65953 - Migratory Bird Permits; Removal of Regulations Concerning Certain Depredation Orders

    Science.gov (United States)

    2013-11-04

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX92 Migratory Bird Permits; Removal of Regulations.... SUMMARY: We propose to remove regulations that set forth certain depredation orders for migratory birds... these regulations apparently are unused, we propose to remove them. Control of depredating birds...

  9. 75 FR 927 - Migratory Bird Permits; Changes in the Regulations Governing Falconry

    Science.gov (United States)

    2010-01-07

    ... Fish and Wildlife Service 50 CFR Parts 21 and 22 RIN 1018-AW44 Migratory Bird Permits; Changes in the...: Dr. George T. Allen, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, 703-358... now cite for the first time the Birds of Conservation Concern 2008 as restricting the take of...

  10. The morphological development of the locomotor and cardiac muscles of the migratory barnacle goose (Branta leucopsis)

    NARCIS (Netherlands)

    Bishop, CM; Butler, PJ; ElHaj, AJ; Egginton, S; Loonen, MJJE

    1996-01-01

    The masses of the locomotor and cardiac muscles of wild barnacle goose goslings, from a migratory population, were examined systematically during development and their values compared to those of pre-migratory geese. Pre-flight development was typified by approximately linear increases of body, leg,

  11. Noninvasive In Toto Imaging of the Thymus Reveals Heterogeneous Migratory Behavior of Developing T Cells.

    Science.gov (United States)

    Bajoghli, Baubak; Kuri, Paola; Inoue, Daigo; Aghaallaei, Narges; Hanelt, Marleen; Thumberger, Thomas; Rauzi, Matteo; Wittbrodt, Joachim; Leptin, Maria

    2015-09-01

    The migration of developing T cells (thymocytes) between distinct thymic microenvironments is crucial for their development. Ex vivo studies of thymus tissue explants suggest two distinct migratory behaviors of thymocytes in the thymus. In the cortex, thymocytes exhibit a stochastic migration, whereas medullary thymocytes show confined migratory behavior. Thus far, it has been difficult to follow all thymocytes in an entire thymus and relate their differentiation steps to their migratory dynamics. To understand the spatial organization of the migratory behavior and development of thymocytes in a fully functional thymus, we developed transgenic reporter lines for the chemokine receptors ccr9a and ccr9b, as well as for rag2, and used them for noninvasive live imaging of the entire thymus in medaka (Oryzias latipes). We found that the expression of these two chemokine receptors in the medaka juvenile thymus defined two spatially distinct subpopulations of thymocytes. Landmark events of T cell development including proliferation, somatic recombination, and thymic selection can be mapped to subregions of the thymus. The migratory behavior of thymocytes within each of the subpopulations is equally heterogeneous, and specific migratory behaviors are not associated with particular domains in the thymus. During the period when thymocytes express rag2 their migratory behavior was more homogeneous. Therefore, the migratory behavior of thymocytes is partly correlated with their developmental stage rather than being defined by their spatial localization.

  12. Consequences of habitat loss at migratory stopover sites: a theoretical investigation

    NARCIS (Netherlands)

    Weber, T.P.; Houston, A.L.; Ens, B.J.

    1999-01-01

    We use a dynamic optimization model to assess the consequences of habitat loss at migratory stopover sites. We emphasize costs birds face during stopover (e.g. costs of gaining energy), the timing of site use and the behavioural rules birds might use to implement migratory strategies. Behavioural ru

  13. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Science.gov (United States)

    2010-10-01

    ... arrangements for the meeting rooms and associated logistics related to Co-management Council meetings; (2... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Alaska Migratory Bird Co-management... Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and...

  14. Is There a “Migratory Syndrome” Common to All Migrant Birds?

    NARCIS (Netherlands)

    Piersma, Theunis; Pérez-Tris, Javier; Mouritsen, Henrik; Bauchinger, Ulf; Bairlein, Franz

    2005-01-01

    Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a “migratory syndrome,

  15. 锶取代PZN-PMN-PT陶瓷的介电、压电性能研究%Effect of Sr Substitution on the Dielectric and Piezoelectric Properties of PZN-PMN-PT Ceramics

    Institute of Scientific and Technical Information of China (English)

    夏峰; 姚熹

    1999-01-01

    PZN-PMN-PT陶瓷在准同型相界具有良好的介电、压电性能.加入锶后,介电、压电性能有明显提高,居里点降低,同时三方相、四方相含量发生变化,使相界发生移动;在锶的摩尔分数为3%~5%时,压电性能最好.烧结后的样品经850℃退火处理后,样品的介电、压电性能均有大幅度提高,得到了压电系数d33高达680pC/N,d33达到-283pC/N,机电耦合系数kp达到55%,k31达到31%,峰值介电常数εm约为2.5万的压电陶瓷.

  16. Research on Preparation and Dielectric Properties of Fluorine Substituted PMN-PT Ceramics%氟取代PMN-PT陶瓷的制备与介电性能研究

    Institute of Scientific and Technical Information of China (English)

    刘敏; 曹林洪

    2006-01-01

    以PbF2为氟源,采用半化学法成功制备了钙钛矿相的F取代PMN-PT陶瓷,并对其体积密度的变化、相的组成、显微结构和介电性能进行了研究.随F含量增加,陶瓷的体积密度增大.与含F试样相比,无F试样的晶粒较大,约10 μm,介电常数峰和介电损耗峰都很尖锐,而且峰值介电常数异常高,约45000;但在含F试样中,含摩尔分数为2% F试样具有较好的显微结构和介电性能,其晶粒约2~3 μm,峰值介电常数约30000.

  17. Why Do Migratory Birds Sing on Their Tropical Wintering Grounds?

    Science.gov (United States)

    Sorensen, Marjorie C; Jenni-Eiermann, Susanne; Spottiswoode, Claire N

    2016-03-01

    Many long-distance migratory birds sing extensively on their tropical African wintering grounds, but the function of this costly behavior remains unknown. In this study, we carry out a first empirical test of three competing hypotheses, combining a field study of great reed warblers (Acrocephalus arundinaceus) wintering in Africa with a comparative analysis across Palearctic-African migratory songbird species. We asked whether winter song (i) functions to defend nonbreeding territories, (ii) functions as practice to improve complex songs for subsequent breeding, or (iii) is a nonadaptive consequence of elevated testosterone carryover. We found support for neither the long-assumed territory-defense hypothesis (great reed warblers had widely overlapping home ranges and showed no conspecific aggression) nor the testosterone-carryover hypothesis (winter singing in great reed warblers was unrelated to plasma testosterone concentration). Instead, we found strongest support for the song-improvement hypothesis, since great reed warblers sang a mate attraction song type rather than a territorial song type in Africa, and species that sing most intensely in Africa were those in which sexual selection acts most strongly on song characteristics; they had more complex songs and were more likely to be sexually monochromatic. This study underlines how sexual selection can have far-reaching effects on animal ecology throughout the annual cycle.

  18. Seasonal passerine migratory movements over the arid Southwest

    Science.gov (United States)

    Felix, Rodney K.; Diehl, Robert H.; Ruth, Janet M.

    2008-01-01

    Biannually, millions of Neotropical and Nearctic migratory birds traverse the arid southwestern US-Mexico borderlands, yet our knowledge of avian migration patterns and behaviors in this region is extremely limited. To describe the spatial and temporal patterns of migration, we examined echoes from weather surveillance radar sites across the American Southwest from southern Texas to southwestern Arizona during spring 2005 and 2006 and fall 2005. After taking steps to identify radar echoes dominated by birds, we determined migrants’ speeds, directions, and altitudes. Our results show that in spring, migrants generally fl ew lower and faster than in fall, although much of this overall pattern may be driven by higher fall altitudes and higher ground speeds at some of the easternmost sites in the borderlands. Seasonal differences in migrants’ altitudes can be partially explained by seasonal differences in the altitudes of favorable winds. Seasonal differences in migrant ground speeds might arise for many reasons including variation in winds aloft or the presence of naïve hatchyear birds in fall. In addition, migrating bats may also be present throughout the region in varying degrees in radar data. Flight directions across the region were generally north in spring and south in fall, but also were consistent with the premise that songbird migration in North America is comprised of distinct regional migratory systems.

  19. Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal.

    Science.gov (United States)

    Karmacharya, Dibesh; Manandhar, Sulochana; Sharma, Ajay; Bhatta, Tarka; Adhikari, Pratikshya; Sherchan, Adarsh Man; Shrestha, Bishwo; Bista, Manisha; Rajbhandari, Rajesh; Oberoi, Mohinder; Bisht, Khadak; Hero, Jean-Marc; Dissanayake, Ravi; Dhakal, Maheshwar; Hughes, Jane; Debnath, Nitish

    2015-01-01

    Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO). Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal.

  20. Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal.

    Directory of Open Access Journals (Sweden)

    Dibesh Karmacharya

    Full Text Available Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO. Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal.

  1. Provider's and user's perspective about immunization coverage among migratory and non-migratory population in slums and construction sites of Chandigarh.

    Science.gov (United States)

    Sharma, Vikas; Singh, Amarjeet; Sharma, Vijaylakshmi

    2015-04-01

    Strengthening routine immunization is a corner stone for countries to achieve the United Nations Millennium Development Goal 4 (MDG 4) which aims to reduce under-five mortality by two-thirds and MDG 5 improving maternal health compared to 1990 estimates by 2015. The poor urban newborns are more vulnerable to many health and nutrition problems compared to the non-poor urban counterparts. Therefore there is a need to strengthen health system to cater the needs of urban poor. Standardized WHO30*7 cluster sampling for slums and convenience sampling for construction sites. In depth interviews were conducted for user's as well as provider's perspective about immunization coverage. Two hundred ten children and 210 mothers were enrolled in slums and 100 were sampled from construction sites. The slum workers are considered as non-migratory groups whereas construction site workers are considered as migratory population. Among children, 23 % were fully immunized, 73 % were partially immunized and 3 % were unimmunized in non-migratory population whereas 3 % were fully immunized, 91 % were partially immunized and 6 % were unimmunized in migratory population. Among mothers, 43 and 39 % were fully immunized, 13 and 15 % partially immunized and 43 and 46 % were unimmunized in non-migratory and migratory population, respectively. The various reasons attributed for low coverage are (a) dissatisfaction of the users with the service delivery and procedural delays (bureaucracy), (b) lack of faith in health workers,

  2. 50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

    Science.gov (United States)

    2010-10-01

    ... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed...

  3. 50 CFR 20.109 - Extended seasons, limits, and hours for taking migratory game birds by falconry.

    Science.gov (United States)

    2010-10-01

    ... taking migratory game birds by falconry. 20.109 Section 20.109 Wildlife and Fisheries UNITED STATES FISH..., PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING... taking migratory game birds by falconry. This section provides annual regulations by which falconers...

  4. Effect of the compressive stress on both polarization rotation and phase transitions in PMN-30%PT single crystal

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2014-05-01

    Full Text Available In this paper, we have investigated the dependence of both the electromechanical effect and the electrostriction on the compressive stress in PMN-30%PT single crystal on the basis of single domain polarization rotation model. In the model, the electroelastic energy induced by the compressive stress is taken into account. The results have demonstrated that the compressive stress can lead to a significant change in the initial polarization state in the crystal. The reason lies in the stress induced anisotropy which is the coupling between the compressive stress and the electrostrictive coefficients. Thus, the initial polarization state in single crystal is determined by the combination of both electrocrystalline anisotropy and the stress induced anisotropy. The compressive stress along the [100] axis can make the polarization in the crystal be perpendicular to the stress direction, and make it difficult to be polarized to the saturation. This model is useful for better understanding both the polarization rotation and electromechanical effect in ferroelectric crystals with the compressive stress present.

  5. Development of a 20-MHz wide-bandwidth PMN-PT single crystal phased-array ultrasound transducer.

    Science.gov (United States)

    Wong, Chi-Man; Chen, Yan; Luo, Haosu; Dai, Jiyan; Lam, Kwok-Ho; Chan, Helen Lai-Wa

    2017-01-01

    In this study, a 20-MHz 64-element phased-array ultrasound transducer with a one-wavelength pitch is developed using a PMN-30%PT single crystal and double-matching layer scheme. High piezoelectric (d33>1000pC/N) and electromechanical coupling (k33>0.8) properties of the single crystal with an optimized fabrication process involving the photolithography technique have been demonstrated to be suitable for wide-bandwidth (⩾70%) and high-sensitivity (insertion loss ⩽30dB) phased-array transducer application. A -6dBbandwidth of 91% and an insertion loss of 29dBfor the 20-MHz 64-element phased-array transducer were achieved. This result shows that the bandwidth is improved comparing with the investigated high-frequency (⩾20MHz) ultrasound transducers using piezoelectric ceramic and single crystal materials. It shows that this phased-array transducer has potential to improve the resolution of biomedical imaging, theoretically. Based on the hypothesis of resolution improvement, this phased-array transducer is capable for small animal (i.e. mouse and zebrafish) studies.

  6. Investigations on ferroelectric PMN-PT and PZN-PT single crystals ability for power or resonant actuators.

    Science.gov (United States)

    Lebrun, L; Sebald, G; Guiffard, B; Richard, C; Guyomar, D; Pleska, E

    2004-04-01

    Ferroelectric single crystals of PZN-PT and PMN-PT exhibit outstanding properties: high charge coefficient (dij), high coupling factor (kij) and high strain levels under DC fields. Besides, their mechanical quality factor is believed to be low. Their usefulness for non-resonant or large bandwidth transducers has therefore been previously investigated. However, few studies have been devoted to the dielectric and mechanical losses of single crystals and to their stability under high levels of excitations (electric fields, temperature and mechanical stress). A knowledge and understanding of such performances is needed to determine whether single crystals are suitable materials for power or resonant transducers. In this work, losses and non-linearity versus external excitations are investigated. Dielectric losses and mechanical losses are measured versus electric field for different compositions, orientations. The evolution of d33 and epsilonT33 are obtained versus electric field and temperature for the longitudinal mode. Strain and hysteresis versus sweep mode (up and down) are measured near the resonance frequency using a laser Doppler vibrometer.

  7. Electric field controlled strain induced reversible switching of magnetization in Galfenol nanomagnets delineated on PMN-PT substrate

    Science.gov (United States)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    We report a non-volatile converse magneto-electric effect in elliptical Galfenol (FeGa) nanomagnets of ~300 nm lateral dimensions and ~10nm thickness delineated on a PMN-PT substrate. This effect can be harnessed for energy-efficient non-volatile memory. The nanomagnets are fabricated with e-beam lithography and sputtering. Their major axes are aligned parallel to the direction in which the substrate is poled and they are magnetized in this direction with a magnetic field. An electric field in the opposite direction generates compressive strain in the piezoelectric substrate which is partially transferred to the nanomagnets and rotates their magnetization away from the major axes to metastable orientations. There they remain after the field is removed, resulting in non-volatility. Reversing the electric field generates tensile strain which returns the magnetization to the original state. The two states can encode two binary bits which can be written using the correct voltage polarity, resulting in non-toggle behavior. Scaled memory fashioned on this effect can exhibit write energy dissipation of only ~2 aJ. Work is supported by NSF under ECCS-1124714 and CCF-1216614. Sputtering was carried out at NIST Gaithersburg.

  8. Minute-Scale Rapid Variability of Optical Polarization in Narrow-Line Seyfert 1 Galaxy: PMN J0948+0022

    CERN Document Server

    Itoh, Ryosuke; Fukazawa, Yasushi; Kawabata, Koji S; Kawaguchi, Kenji; Moritani, Yuki; Takaki, Katsutoshi; Ueno, Issei; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi; Hanayama, Hidekazu; Miyaji, Takeshi; Kawai, Nobuyuki

    2013-01-01

    We report on optical photopolarimetric results of the radio-loud narrow line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in near infrared and gamma-ray bands. Thanks to one-shot polarimetry of the HOWPol installed to the Kanata telescope, we have detected very rapid variability in the polarized-flux light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 sec and 180 sec, respectively. The polarization degree (PD) reached 36 +/- 3% at the peak of the short-duration pulse, while polarization angle (PA) remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 min was present. The high PD and minute-scale variability in polarized flux provides a clear evidence of synchrotron radiation from a very compact emission region of 10^14 cm size with highly or...

  9. Discovery of Luminous Star Formation in PMN1452-5910/IRAS14482-5857: the Pterodactyl Nebula

    CERN Document Server

    Jones, D I

    2014-01-01

    We present sensitive 1-3 GHz ATCA radio continuum observations of the hitherto unresolved star forming region known as either IRAS14482-5857 or PMN1452-5910. At radio continuum frequencies, this source is characterised by a "filled-bubble" structure reminiscent of a classical HII region, dominated by three point sources, and surrounded by low-surface-brightness emission out to the $3'\\times4'$ source extent observed at other frequencies in the literature. The infrared emission corresponds well to the radio emission, with polycyclic aromatic hydrocarbon emission surrounding regions of hot dust towards the radio bubbles. A bright 4.5 $\\mu$m point source is seen towards the centre of the radio source, suggesting a young stellar object. There is also a linear, outflow-like structure radiating brightly at 8 and 24 $\\mu$m towards the brightest peak of the radio continuum. In order to estimate the distance to this source, we have used Mopra Southern Galactic Plane CO Survey $^{12}$CO(1-0) and $^{13}$CO(1-0) molecula...

  10. Multiwavelength observations of the gamma-ray emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011

    CERN Document Server

    D'Ammando, F; Orienti, M; Raiteri, C M; Angelakis, E; Carraminana, A; Carrasco, L; Drake, A J; Fuhrmann, L; Giroletti, M; Hovatta, T; Max-Moerbeck, W; Porras, A; Readhead, A C S; Recillas, E; Richards, J L

    2013-01-01

    We report on radio-to-gamma-ray observations during 2011 May-September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in gamma-rays by Fermi-LAT. Strong variability was observed in gamma-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems to have no counterpart in gamma-rays. This different behaviour could be related to a bending and inhomogeneous jet or a turbulent extreme multi-cell scenario. The radio spectra showed a variability pattern typical of relativistic jets. The XMM spectrum shows that the emission from the jet dominates above 2 keV, while a soft X-ray excess is evident in the low-energy part of the X-ray spectrum. Models where the soft emission is partly produced by blurred reflection or Comptonisation of the thermal disc emission provide good fits to the data. The X-ray spectral slope is similar to that found in radio-quiet NLSy1, suggesting that a standard accretion disc is present, as expect...

  11. Estudio de la adición de K+ y LiNbO3 en las propiedades finales del Relaxor PMN procesado por mezcla de polvos

    Directory of Open Access Journals (Sweden)

    Fernández, J. F.

    2004-06-01

    Full Text Available PMN ceramic relaxor has been investigated by several researchers and many aspects of this material, like powder morphology, phase decomposition, weight loss during sintering process, densification, between others, still are investigated. PMN powder preparation has been shown more efficient when synthesized by columbite route, however lead addition stage for the PMN powder synthesis remains problematical. Therefore, this work proposes a new association of methodologies, using columbite route and the hydroxide precipitation method. Through use of the powder mixture technique, which permitted to obtain good green and sintered densities, was possible to observe K+ y Li+ dopants reduce weight loss in sintering process and change significantly the dielectric properties. Addition of LiNbO3 seeds in conformation stage, which react in a distinct way as a function of the particle size, promotes the formation of differenced grains in the ceramic bulk. Consequently, very different dielectrics properties from conventional PMN ceramic were obtained.El relaxor cerámico PMN ha sido investigado por un gran número de investigadores en el transcurso del tiempo y muchos aspectos de este material, como la morfología de los polvos, descomposición de fases, pérdida de peso en el proceso de sinterización, densificación, entre otras, siguen siendo objetos de investigación. La preparación de polvos de PMN se ha mostrado más efectiva cuando son sintetizados por la ruta de la columbita, pero la etapa de adición de plomo para la síntesis de polvos de PMN todavía sigue problemática. Por lo tanto, este trabajo propone una nueva asociación de metodologías, utilizando la ruta de la columbita y el método de precipitación por hidróxidos. Mediante la utilización de una técnica de mezcla de polvos, la cual permitió lograr buenas densidades en verde y sinterizadas, fue posible observar que los dopantes K+ y Li+ reducen las pérdidas de peso en el proceso de

  12. Fabrication and comparison of PMN-PT single crystal, PZT and PZT-based 1-3 composite ultrasonic transducers for NDE applications.

    Science.gov (United States)

    Kim, Ki-Bok; Hsu, David K; Ahn, Bongyoung; Kim, Young-Gil; Barnard, Daniel J

    2010-08-01

    This paper describes fabrication and comparison of PMN-PT single crystal, PZT, and PZT-based 1-3 composite ultrasonic transducers for NDE applications. As a front matching layer between test material (Austenite stainless steel, SUS316) and piezoelectric materials, alumina ceramics was selected. The appropriate acoustic impedance of the backing materials for each transducer was determined based on the results of KLM model simulation. Prototype ultrasonic transducers with the center frequencies of approximately 2.25 and 5MHz for contact measurement were fabricated and compared to each other. The PMN-PT single crystal ultrasonic transducer shows considerably improved performance in sensitivity over the PZT and PZT-based 1-3 composite ultrasonic transducers.

  13. Effect of biaxial strain induced by piezoelectric PMN-PT on the upconversion photoluminescence of BaTiO₃:Yb/Er thin films.

    Science.gov (United States)

    Wu, Zhenping; Zhang, Yang; Bai, Gongxun; Tang, Weihua; Gao, Ju; Hao, Jianhua

    2014-11-17

    Thin films of Yb3+/Er3+ co-doped BaTiO3 (BTO:Yb/Er) have been epitaxially grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Biaxial strain can be effectively controlled by applying electric field on PMN-PT substrate. A reversible, in situ and dynamic modification of upconversion photoluminescence in BTO:Yb/Er film was observed via converse piezoelectric effect. Detailed analysis and in situ X-ray diffraction indicate that such modulations are possibly due to the change in the lattice deformation of the thin films. This result suggests an alternative method to rationally tune the upconversion emissions via strain engineering.

  14. PMN Leukocytes and Fibroblasts Numbers on Wound Burn Healing on the Skin of White Rat after Administration of Ambonese Plantain Banana

    Directory of Open Access Journals (Sweden)

    Juniarti

    2012-04-01

    Full Text Available A study of ambonese plantain banana (Musa paradisiaca var sapientum Lamb treatment in burn wound healing on the skin of white rats (Rattus novergicus has been conducted. The wound healing of burn injuries was evaluated by counting the number of PMN leukocytes and fibroblasts at the 7th, 14th, and 21st days following the treatment. The study showed that the decrease in number of PMN leukocytes of subjects treated with ambonese plantain banana was relatively more significant compared to both negative and positive control (Bioplacenton ®. In contrast, an increasing number of fibroblasts was significantly demonstrated at the 14th and 21st days after treatment. In conclusion, ambonese plantain banana treatment in burn injuries will provide better results compared to both positive and negative controls.

  15. 熔盐法制备PMN-PT弛豫铁电陶瓷的显微结构及性能

    Institute of Scientific and Technical Information of China (English)

    赵世玺; 李强

    2005-01-01

    本文研究了熔盐法合成的PMN-PT粉末的烧结特性,以及合成工艺对PMN-PT陶瓷致密度,显微结构和介电性能的影响。结果显示,熔盐合成的粉料具有较小的颗粒尺寸和良好的分散性,能够降低陶瓷的烧结温度,在1150~1180℃范围烧结可得到致密度≥96%的PMN-PT陶瓷。在1100~1200℃烧结温度范围,硫酸盐熔盐体系制备的陶瓷呈沿晶断裂,而氯化物熔盐体系制备的陶瓷均呈穿晶断裂。在相同的烧结温度下,氯化物熔盐制备的陶瓷的晶粒尺寸明显大于硫酸盐熔盐体系的陶瓷的晶粒尺寸。用熔盐法制备的组分为0.67PMN.0.33PT陶瓷具有优良的压电和介电性能。在1175℃/2h烧结条件下,制备的0.67PMN-0.33PT陶瓷的最大介电常数为29385,d33≈660pC/N。

  16. Room-temperature magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films

    Science.gov (United States)

    Garg, T.; Kulkarni, A. R.; Venkataramani, N.

    2016-08-01

    The magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films prepared on a glass substrate using RF magnetron sputtering has been investigated in this work. PMN-PT thin films (i.e. PMN-PT/LCMO/Pt/Ti/glass) deposited on glass were used as a substrate for deposition of ZnFe2O4 thin films. ZnFe2O4 thin films were annealed ex situ at different temperatures. Structural, magnetic, ferroelectric, dielectric and magneto-dielectric studies were carried out on these multiferroic bilayer thin films. Structural studies revealed the presence of each layer in its respective single phase. Magnetic and ferroelectric studies revealed the ferromagnetic and ferroelectric behaviors of these bilayers. To quantify the magnetoelectric coupling, the dielectric constant of the bilayer was measured at room temperature as a function of frequency with and without the applied magnetic field. The magneto-dielectric response MD(%) was calculated by finding the relative change in dielectric constant at 1 kHz as a percentage. The observed MD response was correlated with magnetization of the ferrite layer. An MD response of 2.60% was found for a bilayer film annealed at 350 °C. At this particular annealing temperature, the ZnFe2O4 layer also has the highest saturation magnetization of 1900 G.

  17. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering.

    Science.gov (United States)

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-07-17

    We report the tunable near-infrared luminescence of Ni(2+) doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni(2+) ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources.

  18. The quorum-sensing molecule N-3-oxododecanoyl homoserine lactone (3OC12-HSL) enhances the host defence by activating human polymorphonuclear neutrophils (PMN).

    Science.gov (United States)

    Wagner, Christof; Zimmermann, Sabine; Brenner-Weiss, Gerald; Hug, Friederike; Prior, Birgit; Obst, Ursula; Hänsch, Gertrud Maria

    2007-01-01

    The P. aeruginosa quorum-sensing molecule N-3-oxododecanoyl homoserine lactone (3OC12-HSL) interacts not only with bacteria, but also with mammalian cells, among others with those of the immune defence system. We focussed on the possible interaction of 3OC12-HSL with human polymorphonuclear neutrophils (PMN), because these cells are the first to enter an infected site. We found that 3OC12-HSL attracts PMN, and up-regulates expression of receptors known to be involved in host defence, including the adhesion proteins CD11b/CD18 and the immunoglobulin receptors CD16 and CD64. Furthermore, the uptake of bacteria (phagocytosis), which is crucial for an efficient defence against infection, was enhanced. Thus, recognising and responding to 3OC12-HSL not only attracts the PMN to the site of a developing biofilm, but also reinforces their defence mechanisms, and hence could be a means to control the infection in an early stage and to prevent biofilm formation.

  19. Optical-NIR spectroscopy of the puzzling gamma-ray source 3FGL 1603.9-4903/PMN J1603-4904 with X-shooter

    CERN Document Server

    Goldoni, P; Boisson, C; Mueller, C; Dauser, T; Jung, I; Krauss, F; Lenain, J -P; Sol, H

    2015-01-01

    The Fermi/LAT instrument has detected about two thousands Extragalactic High Energy (E > 100 MeV) gamma-ray sources. One of the brightest is 3FGL 1603.9-4903, associated to the radio source PMN J1603-4904. Its nature is not yet clear, it could be either a very peculiar BL Lac or a CSO (Compact Symmetric Object) radio source, considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in gamma-rays for this class of objects. Recently a redshift z=0.18 +/- 0.01 has been claimed on the basis of the detection of a single X-ray line at 5.44 +/- 0.05 keV interpreted as a 6.4 keV (rest frame) fluorescent line. We aim to investigate the nature of 3FGL 1603.9-4903/PMN J1603-4904 using optical to NIR spectroscopy. We observed PMN J1603-4904 with the UV-NIR VLT/X-shooter spectrograph for two hours. We extracted spectra in the VIS and NIR range that we calibrated in flux and corrected for telluric absorption and we systematically searched for absorption and emission features. T...

  20. Measurement of Quadratic Electro-Optic Coefficient of PMN-PT Transparent Ceramics Based on Ultrahigh-Order Guide Modes%利用超高阶导模测量PMN-PT透明陶瓷二次电光系数

    Institute of Scientific and Technical Information of China (English)

    冉茂武; 陈险峰; 曹庄琪

    2011-01-01

    Ultrahigh-order guide modes are excited by employing the free-space coupling technique in a symmetrical metal-cladding optical waveguide fabricated with a submillimeter-scale transparent PMN-PT ceramics. The voltage-dependent variation of the reflectivity of the light intensity is obtained according to the shift of the attenuated total reflection (ATR) resonance dip and the quadratic electro-optic coefficient of the transparent PMN-PT ceramics is then calculated.%以亚毫米尺度的铌镁酸铅-钛酸铅(PMN-PT)透明陶瓷片为导波层制备了对称金属包覆波导,并利用自由空间耦合技术激发了波导中的超高阶导模.根据衰减全反射(ATR)峰的移动,得到了在波导两侧所施加电压与光强反射率的关系,从而计算了PMN-PT透明陶瓷片的二次电光系数.

  1. Lateralization of magnetic compass orientation in a migratory bird

    Science.gov (United States)

    Wiltschko, Wolfgang; Traudt, Joachim; Güntürkün, Onur; Prior, Helmut; Wiltschko, Roswitha

    2002-10-01

    Lateralization of brain functions, once believed to be a human characteristic, has now been found to be widespread among vertebrates. In birds, asymmetries of visual functions are well studied, with each hemisphere being specialized for different tasks. Here we report lateralized functions of the birds' visual system associated with magnetoperception, resulting in an extreme asymmetry of sensing the direction of the magnetic field. We found that captive migrants tested in cages with the magnetic field as the only available orientation cue were well oriented in their appropriate migratory direction when using their right eye only, but failed to show a significant directional preference when using their left eye. This implies that magnetoreception for compass orientation, assumed to take place in the eyes alongside the visual processes, is strongly lateralized, with a marked dominance of the right eye/left brain hemisphere.

  2. [New international migrations and migratory models in South European countries].

    Science.gov (United States)

    De Filippo, E; Pugliese, E

    1996-01-01

    Trends in international migration in the Mediterranean European countries over the course of the 1980s are reviewed. "Particular attention is paid to the different factors that explain the arrival of these migratory fluxes during a period of economic recession and in areas where there is a co-presence of immigration, emigration and unemployment. The involvement of southern European countries as target countries for immigration is not seen as a simple consequence of the [restrictive policies] practiced in the Seventies by European countries with traditional immigration; the push towards these countries as well as the pull to the same are also considered, particularly the acceleration of the internationalization process of the labor markets, the characteristics of the labor markets, and processes of segmentation and tertiarization." (EXCERPT)

  3. Differential regulation of adipokines may influence migratory behavior in the white-throated sparrow (Zonotrichia albicollis.

    Directory of Open Access Journals (Sweden)

    Erica F Stuber

    Full Text Available White-throated sparrows increase fat deposits during pre-migratory periods and rely on these fat stores to fuel migration. Adipose tissue produces hormones and signaling factors in a rhythmic fashion and may be controlled by a clock in adipose tissue or driven by a master clock in the brain. The master clock may convey photoperiodic information from the environment to adipose tissue to facilitate pre-migratory fattening, and adipose tissue may, in turn, release adipokines to indicate the extent of fat energy stores. Here, we present evidence that a change in signal from the adipokines adiponectin and visfatin may act to indicate body condition, thereby influencing an individual's decision to commence migratory flight, or to delay until adequate fat stores are acquired. We quantified plasma adiponectin and visfatin levels across the day in captive birds held under constant photoperiod. The circadian profiles of plasma adiponectin in non-migrating birds were approximately inverse the profiles from migrating birds. Adiponectin levels were positively correlated to body fat, and body fat was inversely related to the appearance of nocturnal migratory restlessness. Visfatin levels were constant across the day and did not correlate with fat deposits; however, a reduction in plasma visfatin concentration occurred during the migratory period. The data suggest that a significant change in the biological control of adipokine expression exists between the two migratory conditions and we propose a role for adiponectin, visfatin and adipose clocks in the regulation of migratory behaviors.

  4. Phenological and geographical shifts have interactive effects on migratory bird populations.

    Science.gov (United States)

    James, Aubrie R M; Abbott, Karen C

    2014-01-01

    For many taxa, ranges are shifting toward the poles and the timing of seasonal reproduction is advancing in response to climate change. For migratory birds, changes such as these could produce particularly strong impacts because of their potential to affect migratory timing and distance. Due to the relatively complex life histories of migratory species, however, it is difficult to intuit exactly what these impacts will be. Here, we develop a general population model for a long-distance migrant, introducing a framework for understanding the potential implications of changes in both phenology and migratory distance for bird abundances. We find that population sizes may increase with either shorter or longer migratory distances, depending on the nature of any concurrent phenological changes. This interaction between timing and distance suggests a need to consider multiple potential responses to climate change simultaneously in order to understand the overall impact of climate change on migratory populations. Our results reveal a degree of variability in the qualitative nature of this phenology-distance interaction, suggesting a possible explanation for observed variation in how migratory birds have already responded to climate change.

  5. Tracking climate impacts on the migratory monarch butterfly

    Science.gov (United States)

    Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

    2012-01-01

    Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to

  6. Serotonin enhances solitariness in phase transition of the migratory locust

    Directory of Open Access Journals (Sweden)

    Xiaojiao eGuo

    2013-10-01

    Full Text Available The behavioral plasticity of locusts is a striking trait presented during the reversible phase transition between solitary and gregarious individuals. However, the results of serotonin as a neurotransmitter from the migratory locust Locusta migratoria in phase transition showed an alternative profile compared to the results from the desert locust Schistoserca gregaria. In this study, we investigated the roles of serotonin in the brain during the phase change of the migratory locust. During the isolation of gregarious nymphs, the concentration of serotonin in the brain increased significantly, whereas serotonin receptors (i.e. 5-HT1, 5-HT2 and 5-HT7 we identified here showed invariable expression patterns. Pharmacological intervention showed that serotonin injection in the brain of gregarious nymphs did not induced the behavior change toward solitariness, but injection of this chemical in isolated gregarious nymphs accelerated the behavioral change from gregarious to solitary phase. During the crowding of solitary nymphs, the concentration of serotonin in the brain remained unchanged, whereas 5-HT2 increased after 1 h of crowding and maintained stable expression level thereafter. Activation of serotonin-5-HT2 signaling with a pharmaceutical agonist inhibited the gregariousness of solitary nymphs in crowding treatment. These results indicate that the fluctuations of serotonin content and 5-HT2 expression are results of locust phase change. Overall, this study demonstrates that serotonin enhances the solitariness of the gregarious locusts. Serotonin may regulate the withdrawal-like behavioral pattern displayed during locust phase change and this mechanism is conserved in different locust species.

  7. Contrasting patterns of genetic differentiation among Blackcaps (Sylvia atricapilla with divergent migratory orientations in Europe.

    Directory of Open Access Journals (Sweden)

    Raeann Mettler

    Full Text Available Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW or southeastern (SE wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants, but not among western populations (i.e. NW and SW migrants, revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow

  8. Contrasting Patterns of Genetic Differentiation among Blackcaps (Sylvia atricapilla) with Divergent Migratory Orientations in Europe

    Science.gov (United States)

    Mettler, Raeann; Schaefer, H. Martin; Chernetsov, Nikita; Fiedler, Wolfgang; Hobson, Keith A.; Ilieva, Mihaela; Imhof, Elisabeth; Johnsen, Arild; Renner, Swen C.; Rolshausen, Gregor; Serrano, David; Wesołowski, Tomasz; Segelbacher, Gernot

    2013-01-01

    Migratory divides are thought to facilitate behavioral, ecological, and genetic divergence among populations with different migratory routes. However, it is currently contentious how much genetic divergence is needed to maintain distinct migratory behavior across migratory divides. Here we investigate patterns of neutral genetic differentiation among Blackcap (Sylvia atricapilla) populations with different migratory strategies across Europe. We compare the level of genetic divergence of populations migrating to southwestern (SW) or southeastern (SE) wintering areas with birds wintering in the British Isles following a recently established northwesterly (NW) migration route. The migratory divide between SW and SE wintering areas can be interpreted as a result of a re-colonization process after the last glaciation. Thus we predicted greater levels of genetic differentiation among the SW/SE populations. However, a lack of genetic differentiation was found between SW and SE populations, suggesting that interbreeding likely occurs among Blackcaps with different migratory orientations across a large area; therefore the SW/SE migratory divide can be seen as diffuse, broad band and is, at best, a weak isolating barrier. Conversely, weak, albeit significant genetic differentiation was evident between NW and SW migrants breeding sympatrically in southern Germany, suggesting a stronger isolating mechanism may be acting in this population. Populations located within/near the SW/SE contact zone were the least genetically divergent from NW migrants, confirming NW migrants likely originated from within the contact zone. Significant isolation-by-distance was found among eastern Blackcap populations (i.e. SE migrants), but not among western populations (i.e. NW and SW migrants), revealing different patterns of genetic divergence among Blackcap populations in Europe. We discuss possible explanations for the genetic structure of European Blackcaps and how gene flow influences the

  9. Migratory corridors of adult female Kemp’s ridley turtles in the Gulf of Mexico

    Science.gov (United States)

    Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Pena, Jaime; Gamez, Daniel Gomez; Gonzales Diaz Miron, Raul de Jesus; Burchfield, Patrick M.; Martinez, Hector J.; Ortiz, Jaime

    2016-01-01

    For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n = 80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n = 14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n = 13); and Gulf Shores, Alabama, USA during 2012 (GS; n = 1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26 m and a mean distance of 20 km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16 year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

  10. [The evolution of the migratory flows in South Catalonia, 1950-1975].

    Science.gov (United States)

    Miret, N

    1997-01-01

    "This paper retraces the history and the geography of the substitution in the migratory flows to Catalonia...during the last 30 years. After the huge movement of internal migration during the first half of the twentieth century, the first flow of foreign migrants appeared in the [1970s]. This substitution of migratory origin is related to a reconfiguration of the immigrants' geographic polarity of settlements and in their economic role. Based on various statistical indicators and bibliographic references, this paper provides some essential elements for the understanding of the migratory complexity of this space." (EXCERPT)

  11. Advancing migratory bird conservation and management by using radar: An interagency collaboration

    Science.gov (United States)

    Ruth, Janet M.; Barrow, Wylie C.; Sojda, Richard S.; Dawson, Deanna K.; Diehl, Robert H.; Manville, Albert; Green, Michael T.; Krueper, David J.; Johnston, Scott

    2005-01-01

    Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected or proposed across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

  12. Equivalent properties of 1-3 piezocomposites made of PMN-PT single crystals for underwater sonar transducers

    Science.gov (United States)

    Kim, Jinwook; Roh, Yongrae

    2011-04-01

    The design of a piezocomposite transducer is accomplished by such advanced modeling technique as finite element method (FEM). However, accurate analysis of a 1-3 piezocomposite transducer enforces three dimensional (3D) modeling that requires very finemeshing of the transducer structure, which is frequently over affordable calculation resource capacity. In order to simplify the FEM model for complicated underwater transducers, the 1-3 piezocomposite needs to be simulated with a single phase material of equivalent properties. The 1-3 piezocomposite material in this study is made of the PMN-PT single crystal as the active material and urethane as the matrix material. Theoretical models for the calculation of new material parameters of 1-3 composites having fine lateral periodicity have been derived. For the validation of the equivalent properties, TE (thickness extensional), LE (length extensional), LTE (length thickness extensional), and TS (thickness shear) FEM models have been built to compare the impedance-frequency spectra of the 1-3 composite material and an equivalent material. Through the simulation with the models, all the equivalent elastic, dielectric and piezoelectric constants of the single phase material are determined. Further, 3D and axis-symmetric 2D FEM models of a multi-mode Tonpilz transducer have been constructed with the equivalent material properties. The equivalent material provides a very good correlation between the 2D and 3D transducer models, which is not easily attainable with the full 1-3 piezocomposite model. This result confirms the efficacy of the equivalent material properties of the 1-3 piezocomposites.

  13. Experimental dental bio-adhesives for direct restorations: the influence of PMnEDM homologs structure on bond strength.

    Science.gov (United States)

    Kupka, Tomasz W; Gibas, Mirosław; Dabrowska, Agnieszka; Tanasiewicz, Marta; Malec, Witold

    2007-10-01

    The purpose of this study was to evaluate the effect of PMnEDM dental monomer homologs chemical structure on shear bond strength between polymer-based composite and alloy. Four light-cured experimental universal dental bio-adhesives (group codes: A (PMDM), B (PM2EDM), C (PM3EDM), D (PM4EDM)) were preliminarily evaluated with respect to sensitivity to ambient light, curing time, depth of cure, and uncured film thickness according to standardized procedures. Appropriate tests were performed to measure shear bond strength (SBS) of polymer-based composite to cobalt-based alloy with the use of the adhesives investigated. Variability of results was evaluated by use of the coefficient of variation (CV). Results were estimated with the aid of one-way analysis of variance (ANOVA), performed on the logarithmic values, with alpha=0.05 significance level. All materials passed the requirements according to physicochemical properties. Except for formulation D, all results estimating SBS were positive with respect to standardized requirements. The uppermost mean SBS was achieved for the A adhesive (11.45 MPa) and appeared to be significantly different compared to D one (5.07 MPa) (p=0.0495). Also the B adhesive, having slightly lower mean SBS value (10.50 MPa) exhibited a significant difference in respect to D one (p=0.0455). The means for other trial pairs did not differ statistically. The materials here studied might be considered to have a practical use in dental clinics, especially the formulations B and C.

  14. Cortical Visual Impairment

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased visual ...

  15. Bear River Migratory Bird Refuge Annual narrative report: Calendar year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1991 calendar year. The report begins with a summary of...

  16. Bear River Migratory Bird Refuge : Narrative report : For period September, October, November, and December, 1945

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments from September through December of 1945. The report begins by summarizing...

  17. Bear River Migratory Bird Refuge trumperter swan translocation project : Issues/action items

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Background information and current issues regarding the trumpeter swan translocation project at Bear River Migratory Bird Refuge. Major issues include harvesting of...

  18. Bear River Migratory Bird Refuge Annual narrative report: Calendar year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with a summary of...

  19. [Quarterly Biological narrative report for November 1940 - January 1941 on the Waubay Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report for Waubay Migratory Waterfowl Refuge covers the biological conditions of the refuge. Weather, vegetation, waterfowl, raptors, upland game birds,...

  20. Annual Report of the Lower Souris Migratory Waterfowl Refuge for the Fiscal Year 1940

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  1. Quarterly Narrative Report for November, December and January 1938 and 1939: Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  2. Medicine Lake Migratory Waterfowl Refuge: Quarterly narrative report: February - March - April 1939

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Medicine Lake Migratory Waterfowl Refuge outlines Refuge accomplishments from February through April of 1939. The report begins by...

  3. Bear River Migratory Bird Refuge : Narrative report : January 1 - December 31, 1971

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1971 calendar year. The report begins by summarizing the...

  4. Bear River Migratory Bird Refuge: Annual narrative report: Calendar year 1978

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments during the 1978 calendar year. The report begins with an introduction to...

  5. Quarterly Narrative Report for August, September and October 1939: Lower Souris Migratory Waterfowl Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower Souris Migratory Waterfowl Refuge (now known as the J. Clark Salyer National Wildlife Refuge) is located just south of the Canadian border in North Dakota....

  6. Bear River Migratory Bird Refuge: Annual narrative report: July 1 - December 31, 1975

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Bear River Migratory Bird Refuge outlines Refuge accomplishments from July through December of 1975. The report begins by...

  7. Seasonal changes in the food preference and its significance in a migratory bird

    National Research Council Canada - National Science Library

    Berthold, P; Berthold, H

    1978-01-01

    The garden warbler (Sylvia borin), a bird of pronounced migratory habit, was studied to determine whether seasonal changes in the type of food consumed depend on the available food supply or on a change in food preference...

  8. Aerial Survey Routes for Wintering, Migratory Waterfowl on Pocosin Lakes National

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document does not have required map criteria but provides important information of the historic and present aerial routes for surveying wintering, migratory...

  9. Ground Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 24, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The ground waterfowl surveys document the number of wintering, migratory waterfowl by species for each management unit on the Pungo Unit of Pocosin Lakes National...

  10. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 7, 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  11. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 1, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  12. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 21, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  13. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 15, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  14. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: March 5, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  15. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 21, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  16. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 30, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  17. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: October 23, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  18. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 18, 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  19. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 17, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  20. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 19, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  1. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 10, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  2. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 2, 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  3. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: October 28, 1999

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  4. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 19, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  5. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 16, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  6. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: November 2, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  7. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 8, 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  8. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 5, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  9. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 13, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  10. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 9, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  11. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 6, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  12. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: March 5, 2005

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  13. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: February 2, 2006.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  14. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 17, 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  15. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 25, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  16. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: January 26, 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  17. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: December 3, 2003

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  18. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: October 22, 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  19. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: October 31, 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...

  20. Aerial Survey for Wintering, Migratory Waterfowl on Pocosin Lakes National Wildlife Refuge: March 2, 2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The aerial waterfowl surveys document the number of wintering, migratory waterfowl by species for management units on Pocosin Lakes National Wildlife Refuge, Lake...