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Sample records for antiferroelectric materials

  1. Effects of raw materials on microstructure and dielectric properties of PbZrO3 antiferroelectric thin films prepared via sol-gel process

    International Nuclear Information System (INIS)

    Highlights: · The effects of starting materials on the microstructure and electrical of PZ AFE thin films were studied. · PZ films obtained from zirconium isopropoxide were highly (1 1 1)-oriented and had a more uniform surface microstructure. · PZ films with zirconium isopropoxide as starting material also displayed improved electrical properties. - Abstract: In this work, we report on two kinds of PbZrO3 (PZO) antiferroelectric (AFE) thin films with a thickness of about 700 nm, which were fabricated by using zirconium isopropoxide and zirconium nitrate as starting materials, respectively. The effects of the raw materials on microstructure and electrical properties of the PZO AFE films were studied in detail. X-ray diffraction and scanning electron microcopy results showed that the PZO films obtained from zirconium isopropoxide were highly (1 1 1)-oriented and had a more uniform surface microstructure. As a result, the PZO films from zirconium isopropoxide accordingly displayed better electrical properties, such as lager dielectric constant, increased saturated polarization, and smaller leakage current.

  2. Antiferroelectric Shape Memory Ceramics

    OpenAIRE

    Kenji Uchino

    2016-01-01

    Antiferroelectrics (AFE) can exhibit a “shape memory function controllable by electric field”, with huge isotropic volumetric expansion (0.26%) associated with the AFE to Ferroelectric (FE) phase transformation. Small inverse electric field application can realize the original AFE phase. The response speed is quick (2.5 ms). In the Pb0.99Nb0.02[(Zr0.6Sn0.4)1-yTiy]0.98O3 (PNZST) system, the shape memory function is observed in the intermediate range between high temperature AFE and low tempera...

  3. Antiferroelectric liquid crystals

    OpenAIRE

    Benguigui, L.; Hardouin, F.

    1981-01-01

    Dielectric investigations have been undertaken in two thermotropic liquid crystal systems exhibiting a smectic A2 phase (i.e. with the layer spacing equal to twice the molecular length). The postulated antiferroelectric ordering has been supported by these measurements. There are anomalies in the dielectric constants ε∥ and ε〉 at the N-S A2 transition and an unusual low frequency relaxation, with a slight temperature dependence, appears around this transition and in the S A phases of these sy...

  4. Unipolar and bipolar fatigue in antiferroelectric lead zirconate thin films and evidences for switching-induced charge injection inducing fatigue

    OpenAIRE

    Lou, X. J.; Wang, J.

    2010-01-01

    For the first time, we show that unipolar fatigue does occur in antiferroelectric capacitors, confirming the predictions of a previous work [Appl. Phys. Lett., 94, 072901 (2009)]. We also show that unipolar fatigue in antiferroelectrics is less severe than bipolar fatigue if the driving field is of the same magnitude. This phenomenon has been attributed to the switching-induced charge injection, the main cause for polarization fatigue in ferroelectric and antiferroelectric materials. Other ev...

  5. Antiferroelectric Shape Memory Ceramics

    Directory of Open Access Journals (Sweden)

    Kenji Uchino

    2016-05-01

    Full Text Available Antiferroelectrics (AFE can exhibit a “shape memory function controllable by electric field”, with huge isotropic volumetric expansion (0.26% associated with the AFE to Ferroelectric (FE phase transformation. Small inverse electric field application can realize the original AFE phase. The response speed is quick (2.5 ms. In the Pb0.99Nb0.02[(Zr0.6Sn0.41-yTiy]0.98O3 (PNZST system, the shape memory function is observed in the intermediate range between high temperature AFE and low temperature FE, or low Ti-concentration AFE and high Ti-concentration FE in the composition. In the AFE multilayer actuators (MLAs, the crack is initiated in the center of a pair of internal electrodes under cyclic electric field, rather than the edge area of the internal electrodes in normal piezoelectric MLAs. The two-sublattice polarization coupling model is proposed to explain: (1 isotropic volume expansion during the AFE-FE transformation; and (2 piezoelectric anisotropy. We introduce latching relays and mechanical clampers as possible unique applications of shape memory ceramics.

  6. Anti-Ferroelectric Ceramics for High Energy Density Capacitors

    Directory of Open Access Journals (Sweden)

    Aditya Chauhan

    2015-11-01

    Full Text Available With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field.

  7. Anti-Ferroelectric Ceramics for High Energy Density Capacitors

    OpenAIRE

    Aditya Chauhan; Satyanarayan Patel; Rahul Vaish; Bowen, Chris R.

    2015-01-01

    With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE) display evidence of being a stro...

  8. Antiferroelectric films of deuterated betaine phosphate

    Science.gov (United States)

    Balashova, E. V.; Krichevtsov, B. B.; Svinarev, F. B.; Zaitseva, N. V.

    2016-07-01

    Thin films of partially deuterated betaine phosphate have been grown by the evaporation on Al2O3(110) and NdGaO3(001) substrates with a preliminarily deposited structure of interdigitated electrodes. The grown films have a polycrystalline block structure with characteristic dimensions of blocks of the order of 0.1-1.5 mm. The degree of deuteration of the films D varies in the range of 20-50%. It has been found that, at the antiferroelectric phase transition temperature T c afe = 100-114 K, the fabricated structures exhibit an anomaly of the electrical capacitance C, which is not accompanied by a change in the dielectric loss tangent tanδ. The strong-signal dielectric response is characterized by the appearance of a ferroelectric nonlinearity at temperatures T > T c afe , which is transformed into an antiferroelectric nonlinearity at T diagram has been constructed.

  9. Diffusive phase transitions in ferroelectrics and antiferroelectrics

    OpenAIRE

    Prosandeev, S. A.; Raevski, I. P.; Waghmare, U. V.

    2003-01-01

    In this paper, we present a microscopic model for heterogeneous ferroelectric and an order parameter for relaxor phase. We write a Landau theory based on this model and its application to ferroelectric PbFe$_{1/2}$Ta$_{1/2}$O$_3$ (PFT) and antiferroelectric NaNbO$_3$:Gd. We later discuss the coupling between soft mode and domain walls, soft mode and quasi-local vibration and resulting susceptibility function.

  10. Giant Negative Electrocaloric Effect in Antiferroelectric La-Doped Pb(ZrTi)O3 Thin Films Near Room Temperature.

    Science.gov (United States)

    Geng, Wenping; Liu, Yang; Meng, Xiangjian; Bellaiche, Laurent; Scott, James F; Dkhil, Brahim; Jiang, Anquan

    2015-05-27

    Antiferroelectric thin films are demonstrated as a new class of giant electrocaloric materials that exhibit a negative electrocaloric response of about -5 K near room temperature. The giant negative electrocaloric effect may open up a new paradigm for light, compact, reliable, and high-efficiency refrigeration devices. PMID:25864588

  11. Highly tunable piezocaloric effect in antiferroelectric PbZrO3

    Science.gov (United States)

    Lisenkov, S.; Mani, B. K.; Cuozzo, J.; Ponomareva, I.

    2016-02-01

    A first-principles-based effective Hamiltonian approach is used to predict the existence of a highly tunable piezocaloric effect in antiferroelectric PbZrO3. The high tunability originates from a strong dependence of both the magnitude and sign of the piezocaloric temperature change on the initial temperature and the nature of the stress. The linearity of the temperature response to the applied stress allows for the doubling of the efficiency of the basic solid state refrigeration cycle. The large values and high tunability of the piezocaloric effect in antiferroelectrics is traced to the strong coupling between the multiple order parameters that coexist in such materials. An experimental setup for the demonstration of such an unusual effect is proposed.

  12. Ferroelectricity and antiferroelectricity of doped thin HfO2-based films.

    Science.gov (United States)

    Park, Min Hyuk; Lee, Young Hwan; Kim, Han Joon; Kim, Yu Jin; Moon, Taehwan; Kim, Keum Do; Müller, Johannes; Kersch, Alfred; Schroeder, Uwe; Mikolajick, Thomas; Hwang, Cheol Seong

    2015-03-18

    The recent progress in ferroelectricity and antiferroelectricity in HfO2-based thin films is reported. Most ferroelectric thin film research focuses on perovskite structure materials, such as Pb(Zr,Ti)O3, BaTiO3, and SrBi2Ta2O9, which are considered to be feasible candidate materials for non-volatile semiconductor memory devices. However, these conventional ferroelectrics suffer from various problems including poor Si-compatibility, environmental issues related to Pb, large physical thickness, low resistance to hydrogen, and small bandgap. In 2011, ferroelectricity in Si-doped HfO2 thin films was first reported. Various dopants, such as Si, Zr, Al, Y, Gd, Sr, and La can induce ferro-electricity or antiferroelectricity in thin HfO2 films. They have large remanent polarization of up to 45 μC cm(-2), and their coercive field (≈1-2 MV cm(-1)) is larger than conventional ferroelectric films by approximately one order of magnitude. Furthermore, they can be extremely thin (5 eV). These differences are believed to overcome the barriers of conventional ferroelectrics in memory applications, including ferroelectric field-effect-transistors and three-dimensional capacitors. Moreover, the coupling of electric and thermal properties of the antiferroelectric thin films is expected to be useful for various applications, including energy harvesting/storage, solid-state-cooling, and infrared sensors. PMID:25677113

  13. FABRICATION AND PROPERTIES OF ANTIFERROELECTRIC RAINBOW ACTUATOR

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new type of large-displacement actuator called reduced and internally biased oxide wafer (RAINBOW) is fabricated by chemical reduction of Pb(Sn, Zr, Ti)O3(PSZT) antiferroelectric ceramics and its properties are investigated. It is found that PSZT is easily reduced and the optimal conditions for producing RAINBOW samples are determined to be 870 ℃ for 2~3 h. The antiferroelectricsferroelectrics phase transitions occur at lower field strength in RAINBOW actuators compared with normal PSZT actuators. Large axial displacements are also obtained from the RAINBOW actuator by application of electric fields exceeding the phase switching level. However, the field-induced displacement of the RAINBOW actuator is dependent on the manner of applying load on the samples.

  14. Negative electrocaloric effect in antiferroelectric PbZrO3

    Science.gov (United States)

    Pirc, R.; Rožič, B.; Koruza, J.; Malič, B.; Kutnjak, Z.

    2014-07-01

    The dielectric and thermal properties of a typical antiferroelectric (AFE) material are investigated by minimising numerically the free energy as given by the Kittel model of AFEs. The phase line of second-order phase transitions in the E\\text{-}T phase diagram is shown to change to a first-order line at the tricritical point T3cp, E3cp. The static dielectric susceptibility and the electrocaloric (EC) effect are calculated as a function of temperature and the applied electric field E. It is found that in a given range of electric fields and temperatures the EC effect has negative values but generally becomes positive above the AFE ordering temperature T0. The dielectric susceptibility shows characteristic peaks at the phase transitions between the field-induced polar and the AFE antipolar phase, and diverges at the tricritical point. We present experimental results for a negative EC effect, which have been obtained by direct EC measurements in PbZrO3 ceramics, and agree qualitatively with the above model.

  15. Gradual phase transition between the smectic- C* and smectic- CA* phases and the thresholdless antiferroelectricity

    OpenAIRE

    VIJ, JAGDISH; Song, Jang-Kun; Fukuda, Atsuo

    2008-01-01

    PUBLISHED We have constructed the phase diagrams for a binary-mixture system of antiferroelectric and ferroelectric liquid-crystalline materials in both thick and thin cells. In the phase diagrams the boundary between the smectic-C* and smectic-CA * phases runs almost parallel to the temperature axis below from ca. 70 ?C down to at least ?25 ?C. The SmC*-SmCA * phase transition for a thin cell shows a large supercooling, and a gradual transition occurs near the boundary. ...

  16. Microstructural evolution in NaNbO3-based antiferroelectrics

    International Nuclear Information System (INIS)

    Our recent study found that CaZrO3 doping can effectively enhance the antiferroelectric P phase in NaNbO3 ceramics, leading to a double polarization hysteresis loop characteristic of a reversible antiferroelectric ↔ ferroelectric phase transition [Shimizu et al., Dalton Trans. 44, 10763 (2015)]. Here, a thorough transmission electron microscope study was performed to illustrate the CaZrO3 doping-assisted antiferroelectricity stabilization. In parallel to the bright-field imaging and selected area electron diffraction from multiple zone axes, detailed dark-field imaging was utilized to determine the superlattice structural origins, from either oxygen octahedral tilting or antiparallel cation displacements. By analogy with Pb(Zr1−xTix)O3 and rare-earth doped BiFeO3 systems, the chemical substitutions are such as to an induced polar-to-antipolar transition that is consistent with a tolerance factor reduction. The resultant chemical pressure has a similar effect to the compressive hydrostatic pressure where the antiferroelectric state is favored over the ferroelectric state

  17. Ferroelectricity in antiferroelectric epitaxial PbZrO3 films with different orientations

    International Nuclear Information System (INIS)

    PbZrO3 (PZO) is a well known antiferroelectric (AFE) material with orthorhombic crystal structure. Due to antiparallel lead-ion shifts the remnant polarization is nominally zero. With a sufficiently large applied electric field, PZO undergoes a field-driven phase transition into a ferroelectric (FE), rhombohedral phase. However, the existence of a FE polarization along the c-axis of PZO (without applied field) was predicted by Jona et al. with an estimated value of 25 μC/cm2. We have investigated the temperature dependence of hysteresis and capacitance in PLD-grown epitaxial PZO films with two different orientations in the 4.2-400 K temperature range. It was observed that (120)o-oriented films (index o-orthorhombic) show a mixed AFE and FE behaviour on the entire temperature range, the FE behaviour being more stable at low temperatures. In contrast, the (001)o-oriented films show a FE hysteresis only at temperatures up to 60 K. Above 60 K the hysteresis splits into two loops, typical for antiferroelectrics. The results indicate the coexistence of FE and AFE properties in PZO films, particularly at low temperature

  18. A high energy density relaxor antiferroelectric pulsed capacitor dielectric

    International Nuclear Information System (INIS)

    Pulsed capacitors require high energy density and low loss, properties that can be realized through selection of composition. Ceramic (Pb0.88La0.08)(Zr0.91Ti0.09)O3 was found to be an ideal candidate. La3+ doping and excess PbO were used to produce relaxor antiferroelectric behavior with slim and slanted hysteresis loops to reduce the dielectric hysteresis loss, to increase the dielectric strength, and to increase the discharge energy density. The discharge energy density of this composition was found to be 3.04 J/cm3 with applied electric field of 170 kV/cm, and the energy efficiency, defined as the ratio of the discharge energy density to the charging energy density, was 0.920. This high efficiency reduces the heat generated under cyclic loading and improves the reliability. The properties were observed to degrade some with temperature increase above 80 °C. Repeated electric field cycles up to 10 000 cycles were applied to the specimen with no observed performance degradation

  19. A high energy density relaxor antiferroelectric pulsed capacitor dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hwan Ryul; Lynch, Christopher S. [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles (UCLA), Los Angeles, California 90095 (United States)

    2016-01-14

    Pulsed capacitors require high energy density and low loss, properties that can be realized through selection of composition. Ceramic (Pb{sub 0.88}La{sub 0.08})(Zr{sub 0.91}Ti{sub 0.09})O{sub 3} was found to be an ideal candidate. La{sup 3+} doping and excess PbO were used to produce relaxor antiferroelectric behavior with slim and slanted hysteresis loops to reduce the dielectric hysteresis loss, to increase the dielectric strength, and to increase the discharge energy density. The discharge energy density of this composition was found to be 3.04 J/cm{sup 3} with applied electric field of 170 kV/cm, and the energy efficiency, defined as the ratio of the discharge energy density to the charging energy density, was 0.920. This high efficiency reduces the heat generated under cyclic loading and improves the reliability. The properties were observed to degrade some with temperature increase above 80 °C. Repeated electric field cycles up to 10 000 cycles were applied to the specimen with no observed performance degradation.

  20. Antiferroelectricity in thin-film ZrO2 from first principles

    Science.gov (United States)

    Reyes-Lillo, Sebastian E.; Garrity, Kevin F.; Rabe, Karin M.

    2014-10-01

    Density-functional calculations are performed to investigate the experimentally reported field-induced phase transition in thin-film ZrO2 [J. Müller et al., Nano Lett. 12, 4318 (2012), 10.1021/nl302049k]. We find a small energy difference of ˜1 meV/f.u. between the nonpolar tetragonal and polar orthorhombic structures, characteristic of antiferroelectricity. The requisite first-order transition between the two phases, which atypically for antiferroelectrics have a group-subgroup relation, results from coupling to other zone-boundary modes, as we show with a Landau-Devonshire model. Tetragonal ZrO2 is thus established as a lead-free antiferroelectric with excellent dielectric properties and compatibility with silicon. In addition, we demonstrate that a ferroelectric phase of ZrO2 can be stabilized through epitaxial strain, and suggest an alternative stabilization mechanism through continuous substitution of Zr by Hf.

  1. Electron emission from La-doped Pb(Zr,Sn,Ti)O_3 anti-ferroelectrics by pulse electric field and the relevant physical mechanism

    Institute of Scientific and Technical Information of China (English)

    ZHANG LinLi; FENG YuJun; XU Zhuo; SHENG ZhaoXuan

    2009-01-01

    We investigate the characteristics of emission current waves of antiferroelectric cathode material lanthanum-doped lead zirconate stannate titanate (PLZST) triggered by pulse field, and analyze the relationship of the emission current waveforms with the extraction voltage. The close correlation between the triggering pulse polarity and emission current waveform observed evidences the relevant physical process of electron emission. We speculate that the primary emission may result from local phase transition and field emission in the vicinity of triple junctions, and the plasma formation may enhance the electron emission.

  2. Quadrupolar Effect on Two Layered Thin Film Antiferroelectric Smectic Liquid Crystal

    International Nuclear Information System (INIS)

    Within the framework of the discrete Landau phenomenological model, the free energy of an antiferroelectric smectic liquid crystal is analyzed. This model considers the interactions between the liquid crystal molecules within the nearest and the next nearest layers. Electrostatic quadrupolar interaction up to the nearest layers is included. This quadrupolar term, bqξ???i·ξ???i+12 is positive, thus favouring a perpendicular orientation in the adjacent layer respectively. We show how quadrupolar interaction can affects the planar regions of the phase diagram of a two layered thin antiferroelectric smectic liquid crystal film.

  3. Pyroelectric spectrum in Pb(Zr,Sn,Ti)O3 antiferroelectric- ferroelectric ceramics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(Zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.

  4. Fabrication of antiferroelectric PLZT films on metal foils

    International Nuclear Information System (INIS)

    Fabrication of high-dielectric-strength antiferroelectric (AFE) films on metallic foils is technically important for advanced power electronics. To that end, we have deposited crack-free Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT 8/95/5) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was coated by chemical solution deposition on the nickel foil before the deposition of PLZT. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be processed in air. With the PLZT 8/95/5 deposited on LNO-buffered Ni foils, we observed field- and thermal-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, EAF = 225 kV/cm, and the reverse phase transition field, EFA = 190 kV/cm, were measured at room temperature on a ∼1.15 μm-thick PLZT 8/95/5 film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were ∼600 and ∼730, respectively, with dielectric loss ∼0.04 at room temperature. The Curie temperature was ∼210 deg. C. The thermal-induced transition of AFE-to-FE phase occurred at ∼175 deg. C. Breakdown field strength of 1.2 MV/cm was measured at room temperature

  5. Suppression of the antiferroelectric phase during polarization cycling of an induced ferroelectric phase

    International Nuclear Information System (INIS)

    The ceramic Pb0.99Nb0.02[(Zr0.57Sn0.43)0.92Ti0.08]0.98O3 can exist in either an antiferroelectric or a ferroelectric phase at room temperature, depending on the thermal and electrical history. The antiferroelectric phase can be partially recovered from the induced ferroelectric phase when the applied field reverses polarity. Therefore, polarization cycling of the ferroelectric phase in the ceramic under bipolar fields at room temperature is accompanied with repeated phase transitions. In this letter, the stability of the recovered antiferroelectric phase upon electrical cycling of the ceramic is investigated. Ex-situ X-ray diffraction reveals that bipolar cycling suppresses the antiferroelectric phase; this is indirectly supported by piezoelectric coefficient d33 measurements. It is speculated that the accumulated charged point defects during polarization cycling stabilize the polar ferroelectric phase. The findings presented are important to the fundamental studies of electric fatigue and field-induced phase transitions in ferroelectrics

  6. From antiferroelectricity to ferroelectricity in smectic mesophases formed by bent-core molecules

    Indian Academy of Sciences (India)

    Carsten Tschierske; Gert Dantlgraber

    2003-08-01

    This contribution gives an overview of ferroelectric switching liquid crystalline phases formed by bent-core molecules. First a description of some general principles behind the mesophase formation within bent-core systems will be given, followed by a short review of the mesophase structures formed by such molecules. Then, different classes of ferroelectric switching bent-core mesogens will be described. This type of switching behaviour has been reported for several subtypes of polar smectic phases (B2, B5, B7 and SmCG) and recently for columnar mesophases. In this discussion particular attention will be made to polyphilic bent-core molecules, composed of three incompatible units, a bent aromatic core, alkyl chains and an oligosiloxane unit. The importance of the decoupling of the layers into microsegregated sublayers for the ferroelectric organisation is discussed. Many of the ferroelectric switching mesophases show dark textures with distinct regions of opposite chirality in their ground states. It is discussed that this might be due to a helical superstructure formed as a result of an escape from macroscopic polar order. Hence, the materials themselves are not ferroelectric in the ground state, but upon alignment within an electric field in the measuring cells the ferroelectric states are stabilised by surface interactions, leading to a ferroelectric switching system. The designing principle was extended to mesogenic dimers with bent-core structural units. For these compounds, depending on the number of dimethylsiloxane units in the spacer either ferroelectric or antiferroelectric switching was observed, whereby the effect of parity is reversed to that observed for conventional calamitic dimesogens. Finally, a carbosilane-based first generation dendrimer is reported. It shows a ferroelectric switching phase, for which a non-correlated organisation of tilted polar smectic layers is proposed (SmCPR).

  7. Electric-field-induced AFE-FE transitions and associated strain/preferred orientation in antiferroelectric PLZST

    Science.gov (United States)

    Lu, Teng; Studer, Andrew J.; Noren, Lasse; Hu, Wanbiao; Yu, Dehong; McBride, Bethany; Feng, Yujun; Withers, Ray L.; Chen, Hua; Xu, Zhuo; Liu, Yun

    2016-01-01

    Electric-field-induced, antiferroelectric-ferroelectric (AFE-FE) phase transitions are common for AFE materials. To date, the strain and preferred orientation evolution as well as the role of the intermediate FE state during the successive AFE-FE-AFE phase transitions has not been clear. To this end, we have herein studied a typical AFE Pb0.97La0.02(Zr0.56Sn0.33Ti0.11)O3 (PLZST) material using in-situ neutron diffraction. It is striking that the AFE-FE phase transition is not fully reversible: in the electric-field-induced FE state, the induced strain exhibits an elliptical distribution, which in turn leads to significant preferred orientation in the final AFE state after withdrawal of the applied electric-field. The ω-dependent neutron diffraction patterns show clear evidence of the induced strain distribution and associated preferred orientation arising from the AFE-FE phase transition. The current work also provides an explanation for several temperature and electric-field dependent dielectric anomalies as well as unrecovered strain change which appear in AFE materials after exposure to sufficiently high electric fields. PMID:27025685

  8. Electric field induced phase transition of antiferroelectric lead lanthanum zirconate titanate stannate ceramics

    International Nuclear Information System (INIS)

    The electric field induced phase transition behavior of lead lanthanum zirconate titanate stannate (PLZTS) ceramics was investigated. PLZTS undergoes a tetragonal antiferroelectric (AFETet) to rhombohedral ferroelectric (FERh) phase transition with the application of an electric field. The volume increase associated with this antiferroelectric (AFE)endash ferroelectric (FE) phase transition plays an important role with respect to actuator applications. This volume increase involves an increase in both transverse and longitudinal strains. The E field at which the transverse strain increases is accompanied by an abrupt jump in polarization. The longitudinal strain, however, lags behind this polarization jump exhibiting a slight decrease at the onset of phase switching. This decoupling was related to the preferentially oriented AFE domain configuration, with its tetragonal c-axis perpendicular to the applied electric field. It is suggested that phase switching involves multiple steps involving both structural transformation and domain reorientation. copyright 1997 American Institute of Physics

  9. Polarity of translation boundaries in antiferroelectric PbZrO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xian-Kui, E-mail: xiankui.wei@epfl.ch [Ceramics Laboratory, EPFL–Swiss Federal Institute of Technology, Lausanne 1015 (Switzerland); Peter Grünberg Institute and Ernst Ruska Center for Microscopy and Spectroscopy with Electrons, Research Center Jülich, 52425 Jülich (Germany); Jia, Chun-Lin [Peter Grünberg Institute and Ernst Ruska Center for Microscopy and Spectroscopy with Electrons, Research Center Jülich, 52425 Jülich (Germany); International Centre of Dielectric Research, The School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Roleder, Krystian [Institute of Physics, University of Silesia, Katowice 40007 (Poland); Setter, Nava [Ceramics Laboratory, EPFL–Swiss Federal Institute of Technology, Lausanne 1015 (Switzerland)

    2015-02-15

    Graphical abstract: Strain-free rigid model and aberration-corrected transmission electron microscopes are used to investigate the polarity of translation boundaries in antiferroelectric PbZrO{sub 3}. - Highlights: • Domain boundaries in antiferroelectric PbZrO{sub 3} show polar and antipolar property. • The antiphase boundary can split into “sub-domains”. • Polarization reversal possibly exists inside the translation boundaries. • Thermal treatment can alter morphology and density of the translation boundaries. - Abstract: The polarity of translation boundaries (TBs) in antiferroelectric PbZrO{sub 3} is investigated. We show that previous experimentally reported polar property of R{sub III-1} type TB can be well approximated by a strain-free rigid model. Based on this, the modeling investigation suggests that there are two additional polar TBs, three antipolar-like TBs and one antipolar antiphase boundary. High-resolution scanning-transmission-electron-microscopy study reveals that the straight R{sub III-1} type TB can split into “sub-domains” with possible polarization reversal, suggesting the occurrence of ferroic orders at the TBs. In addition, dependence of morphology and density of the TBs on thermal treatments is discussed according to our results.

  10. Antiferroelectric polarization switching and dynamic scaling of energy storage: A Monte Carlo simulation

    Science.gov (United States)

    Huang, B. Y.; Lu, Z. X.; Zhang, Y.; Xie, Y. L.; Zeng, M.; Yan, Z. B.; Liu, J.-M.

    2016-05-01

    The polarization-electric field hysteresis loops and the dynamics of polarization switching in a two-dimensional antiferroelectric (AFE) lattice submitted to a time-oscillating electric field E(t) of frequency f and amplitude E0, is investigated using Monte Carlo simulation based on the Landau-Devonshire phenomenological theory on antiferroelectrics. It is revealed that the AFE double-loop hysteresis area A, i.e., the energy loss in one cycle of polarization switching, exhibits the single-peak frequency dispersion A(f), suggesting the unique characteristic time for polarization switching, which is independent of E0 as long as E0 is larger than the quasi-static coercive field for the antiferroelectric-ferroelectric transitions. However, the dependence of recoverable stored energy W on amplitude E0 seems to be complicated depending on temperature T and frequency f. A dynamic scaling behavior of the energy loss dispersion A(f) over a wide range of E0 is obtained, confirming the unique characteristic time for polarization switching of an AFE lattice. The present simulation may shed light on the dynamics of energy storage and release in AFE thin films.

  11. Characteristics of antiferroelectric PbZrO sub 3 thin films

    CERN Document Server

    Kim, I W; Kim, K S; Kim, H K; Lee Jae Sik; Jeong, J H; Yamakawa, K

    1998-01-01

    Antiferroelectric PbZrO sub 3 thin films were synthesized on Pt/Ti/SiO sub 2 /Si substrates by using reactive magnetron co-sputtering followed by rapid thermal annealing. At an annealing temperature of 700.deg.C, the PbZrO sub 3 films exhibited a pure perovskite phase with improved crystallinity as evidenced by higher and sharper (221) and (240) X-ray diffractometer peaks. From the scanning electron microscopy observations, the grains were found to have a columnar structure, and the average grain size was 0.3 - 0.5 mu m. An electric-field-forced transformation from the antiferroelectric phase to the ferroelectric phase was observed at room temperature and had a maximum polarization value of 41 mu C/cm sup 2. The average fields for exciting the ferroelectric state and that for reversing to the antiferroelectric state, as measured by charge versus voltage curves, were 357 kV/cm and 207 kV/cm, respectively. The dielectric constant was 196 with an associated dissipation factor of 0.043 at 100kHz. The frequency-de...

  12. Characteristics of antiferroelectric PbZrO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Il Won; Bae, Sang Bo; Kim, Kun Surb; Kim, Hong Keun [Ulsan Univ., Ulsan (Korea, Republic of); Lee, Jeong Sik [Kyungsung Univ., Pusan (Korea, Republic of); Jeong, Jung Hyun [Pukyong National Univ., Pusan (Korea, Republic of); Yamakawa, K. [Microelectronics Engineering Laboratory, Yokohama (Japan)

    1998-08-01

    Antiferroelectric PbZrO{sub 3} thin films were synthesized on Pt/Ti/SiO{sub 2}/Si substrates by using reactive magnetron co-sputtering followed by rapid thermal annealing. At an annealing temperature of 700.deg.C, the PbZrO{sub 3} films exhibited a pure perovskite phase with improved crystallinity as evidenced by higher and sharper (221) and (240) X-ray diffractometer peaks. From the scanning electron microscopy observations, the grains were found to have a columnar structure, and the average grain size was 0.3 - 0.5 {mu}m. An electric-field-forced transformation from the antiferroelectric phase to the ferroelectric phase was observed at room temperature and had a maximum polarization value of 41 {mu}C/cm{sup 2}. The average fields for exciting the ferroelectric state and that for reversing to the antiferroelectric state, as measured by charge versus voltage curves, were 357 kV/cm and 207 kV/cm, respectively. The dielectric constant was 196 with an associated dissipation factor of 0.043 at 100kHz. The frequency-dependent response indicated no dispersion below 1 MHz. According to the fatigue measurement, the value of P of the PbZrO{sub 3} film switched up to 10{sup 9} cycles which was a decrease of about 15% compared to the value for a virgin film.

  13. μSR studies of hydrogen-bonded ferroelectrics and antiferroelectrics

    International Nuclear Information System (INIS)

    We have performed measurements on crystals of KH2PO4 (KDP, ferroelectric (FE) transition at TFE=123K), NH4H2PO4 (ADP, antiferroelectric (AFE) transition at TAFE=148K) and deuterated ADP (DADP, ND4D2PO4, antiferroelectric transition at TAFE=242K). Compounds of this family are covalently bonded molecular PO4 units linked by a network of hydrogen O-H-O bonds. At any temperature between 2 and 310K, a substantial fraction of the muons implanted into the crystal appears as muonium. At low temperatures (below ∼140K), this fraction reaches about one half. The onset of the ferroelectric or antiferroelectic phase transition seems to differently affect the muon charge state. Longitudinal field decoupling measurements show only weak dynamics in the diamagnetic fraction with decoupling already at fields of about 1.5mT. In the antiferroelectric ADP, the temperature dependence of the static Kubo-Toyabe width obtained from LF global fits exhibits a pronounced increase at the transition temperature

  14. Antiferroelectric phase transition in (Sr1-xCax)TiO3: II. X-ray diffraction studies

    International Nuclear Information System (INIS)

    We present here a detailed Rietveld analysis of the structure of paraelectric and antiferroelectric phases of Sr0.70Ca0.30TiO3 using powder XRD data. It is shown that the observed antiferroelectric superlattice reflections can be explained by doubling of the Co parameter of the orthorhombic paraelectric phase. The space groups of the paraelectric (PE) and antiferroelectric (AFE) phases are shown to be Ibnm and Pbcm respectively. The ionic displacements in the antiferroelectric phase reveal that the Ti4+and Sr2+/Ca2+ ions are displaced in the + [100] direction in a block of three layers followed by their displacements in the -[100] direction in the next block of three layers, leading to the doubling of the cell parameter in the [001] direction. The paraelectric to antiferroelectric phase transition in (Sr0.70Ca0.30)TiO3 and (Sr0.75Ca0.25)TiO3 is shown to be of first order type since (i) the AFE and PE phases coexist around the phase transition temperature and (ii) the lattice parameters change discontinuously at the transition temperature. (author)

  15. Domain, dielectric and optical studies in antiferroelectric (Pb, La) (Zr, Sn, Ti)O3 single crystals

    Science.gov (United States)

    Li, Yuanyuan; Li, Qiang; Wang, Lin; Yang, Zi; Gao, Jinghan; Chu, Xiangcheng

    2012-09-01

    Antiferroelectric (Pb, La) (Zr, Sn, Ti)O3 (PLZST) single crystals have been successfully grown by flux method using PbO-PbF2-B2O3 as the flux. The obtained crystals are pale yellow in color and translucent. Domain structures, dielectric constants and optical transmission measurements have been performed on the -oriented PLZST single crystals. Two types of domains, namely, 90° and 180° domains, are observed. The extinction of 90° domains at P/A: 0° reveals a tetragonal structure in the crystal. The sequence of phase transitions from antiferroelectric to ferroelectric and then paraelectric has been established with increasing temperature. According to the modified Curie-Weiss relationship, the PLZST crystal is in an intermediate state between normal and relaxor antiferroelectrics. The broad optical transparent region (from 0.4 to 7.0 μm) and high optical transmittance (up to 65%) indicate that PLZST crystals are promising for optical uses.

  16. Bistable optical information storage using antiferroelectric-phase lead lanthanum zirconate titanate ceramics

    International Nuclear Information System (INIS)

    A recently discovered photostorage effect in antiferroelectric-phase (AFE-phase) lead lanthanum zirconate titanate (PLZT) compositions appears to be particularly applicable to binary optical information storage. The basis for bistable optical information storage is that exposure to near-UV or visible light shifts the electric field threshold of the phase transition between the field-induced ferroelectric (FE) phase and the stable AFE phase in the direction of the initial AFE → FE phase transition. Properties of this photoactivated shift of the FE → AFE phase transition, including preliminary photosensitivity measurements and photostorage mechanisms, are presented. Photosensitivity enhancement by ion implantation is also discussed

  17. Antiferroelectric surface layers in a liquid crystal as observed by synchrotron x-ray scattering

    DEFF Research Database (Denmark)

    Gramsbergen, E. F.; de Jeu, W. H.; Als-Nielsen, Jens Aage

    1986-01-01

    The X-ray reflectivity form the surface of a liquid crystal with terminally polar (cyano substituted) molecules has been studied using a high-resolution triple-axis X-ray spectrometer in combination with a synchrotron source. It is demonstrated that at the surface of the smectic Al phase a few...... antiferroelectric double layers develop that can be distinguished from the bulk single layer structure. A model is developed that separates the electron density in a contribution from the molecular form factor, and from the structure factor of the mono- and the bilayers, respectively. It shows that (i) the first...

  18. Orientation-dependent energy storage performance and electrocaloric effect in PLZST antiferroelectric thick films

    OpenAIRE

    Zhao, Ye; Gao, Hongcheng; Hao, Xihong; Zhang, Qi

    2016-01-01

    The enhancement of the energy storage performance and electrocaloric effect (ECE) was achieved via orientation control. The 1.5-μm-(Pb0.97La0.02)(Zr0.73Sn0.22Ti0.05)O3 (PLZST) antiferroelectric (AFE) thick films with (111), (110), and (100) crystallographic orientations were successfully prepared via a sol-gel method. It was found that both the enhanced energy-storage density of 13.5 J/cm3 at 900 kV/cm and the corresponding temperature reduction of ΔT = 28.1 °C at room temperature were obtain...

  19. Structural study of the high-pressure antiferroelectric phase of CsH2PO4

    International Nuclear Information System (INIS)

    A three-dimensional neutron diffraction study has been carried out on the pressure-induced antiferroelectric phase of CsH2PO4. At 100.70K and a hydrostatic pressure of 3.6 kbar, the unit cell parameters are a = 15.625(9), b = 6.254(2), c = 4.886(1) A, β = 108.08(3)0 and Z = 4. Atomic parameters were determined using full-matrix least-squares methods which yield final agreement indices: R(F2) = 0.0715, R/sub w/(F2) = 0.0807 and S = 2.13. The structure is nearly consistent with the monoclinic space group P21/a but refinement in P21 yields a slightly better fit. The structure is markedly different from those of the paraelectric and ferroelectric phases with large relative displacements (nearly 1 A) of Cs+1 and PO4-3 groups in the x-z plane. Hydrogens bonding in b-chains, which are disordered in the paraelectric phase, show antiferroelectric order

  20. Finite-size effects in antiferroelectric PbZrO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, Soma; Ayyub, Pushan; Palkar, V.R.; Gurjar, A.V.; Wankar, R.M.; Multani, Manu [Materials Research Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India)

    1997-09-22

    We study the size dependence of the antiferroelectric-to-paraelectric phase transition in ultrafine particles of PbZrO{sub 3} (with x-ray domain size down to approx. 30 nm) prepared by the sol - gel method. The phase transition was investigated by means of dielectric and thermal measurements. The nature of the particle size dependence of various properties of antiferroelectric PbZrO{sub 3} was found to be generally similar to that of typical 'displacive' ferroelectrics such as PbTiO{sub 3} and BaTiO{sub 3}. In both cases, a size-induced structural distortion towards the high-symmetry paraelectric phase appears to dictate the behaviour of the nanoparticulate system. Nanoparticles of 'order -disorder' systems such as NaNO{sub 2} behave in a markedly different manner. With decreasing particle size, we observe an increasing deviation of the dielectric response from the Curie-Weiss behaviour. Certain physical situations that may lead to the observed smearing out of the transition in nanoparticles of PbZrO{sub 3} and PbTiO{sub 3} are discussed. (author)

  1. Observation of coexistence of ferroelectric and antiferroelectric phases in Sc substituted BiFeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Durga Rao, T.; Asthana, Saket, E-mail: asthanas@iith.ac.in; Niranjan, Manish K.

    2015-09-05

    Highlights: • Coexisting ferro- and antiferroelectric phases in Sc substituted compounds. • Structural studies (XRD and Raman) supports the incorporation of Sc at B-site. • Presence of non-centrosymmetric monoclinic phase correlates with AFE ordering. • Grain resistance and activation energies increase with the Sc-content. • Electrical relaxations are originated due to oxygen vacancy movements. - Abstract: Polycrystalline BiFe{sub 1−x}Sc{sub x}O{sub 3} (x = 0, 0.05, 0.10 and 0.15) compounds were prepared using solid state reaction route. The X-ray diffraction patterns showed that Sc substitution stabilized the crystal structure in rhombohedral structure with R3c space group along with nominal percentage of monoclinic structure with Cm space group. Raman and FTIR measurements revealed that the substituent replaced Fe-ions and caused structural distortions. Co-existence of ferroelectric and antiferroelectric phases were observed in Sc substituted BiFeO{sub 3} and antiferroelectric phase is found to be evolved at the expense of ferroelectric phase with the Sc content. The electric field driven effects indicated that antiferroelectric phase was suppressed and ferroelectric phase was enriched. Frequency dependence of dielectric constant (ε{sub r}) and dielectric loss tangent (tan δ) at different temperatures were investigated. Further, grain resistances and grain boundary resistances were increased with the Sc content. Activation energies estimated from dielectric, impedance and modulus data indicated that these relaxations originated presumably due to the oxygen vacancy movements.

  2. Large pyroelectric response in (Pb{sub 0.87}La{sub 0.02}Ba{sub 0.1})(Zr{sub 0.7}Sn{sub 0.3-x} Ti{sub x})O{sub 3} antiferroelectric ceramics under DC bias field

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingfeng; Jiang, Shenglin; Zeng, Yike; Fan, Maoyan; Wang, Qingping; Zhang, Guangzu; Zhang, Yangyang; Yu, Yan; Wang, Jing [Huazhong University of Science and Technology, Department of Electronic Science and Technology, Wuhan (China)

    2011-06-15

    (Pb{sub 0.87}La{sub 0.02}Ba{sub 0.1})(Zr{sub 0.7}Sn{sub 0.3-x} Ti{sub x})O{sub 3} (PLBZST, 0.06 {<=}x {<=}0.09) antiferroelectric ceramics were fabricated by conventional solid state reaction process, and their ferroelectric, dielectric, and pyroelectric properties were systemically investigated. PLBZST with different Ti content were all confirmed to be in an antiferroelectric phase at T=50 C, which is close to the lowest phase transition temperature. Compared with conventional FE ceramics, PLBZST antiferroelectric ceramics exhibited higher electric field induced pyroelectric coefficient (p). As the content of Ti increased from 0.06 to 0.09, the pyroelectric coefficient increased from 1000 to 6500 {mu}C/m {sup 2}K under a 500 V/mm DC bias field. The maximum pyroelectric coefficient of 8400 {mu}C/m {sup 2}K was obtained at x=0.09 when an 850 V/mm DC bias field was applied, which is far larger than that of conventional phase transition pyroelectric materials. Large pyroelectric response is beneficial for the development of infrared detectors and thermal imaging sensors. (orig.)

  3. Large electric-induced pyroelectric properties in (Pb0.87La0.02Ba0.1) (Zr0.7Sn0.24Ti0.06)O3 antiferroelectric ceramics with excess PbO

    International Nuclear Information System (INIS)

    (Pb0.87La0.02Ba0.1) (Zr0.7Sn0.24Ti0.06)O3 (PLBZST) antiferroelectric ceramics with the addition of 0-9 wt. % excess PbO were fabricated by the conventional solid-state reaction process, and their microstructure, dielectric, and pyroelectric properties were systemically investigated. When excess PbO content was less than 9 wt. %, two pyrochlore phases were formed along with the perovskite phase. Compared with common specimens, PLBZST antiferroelectric ceramics with excess PbO exhibited a higher pyroelectric coefficient and a lower dielectric loss, which are beneficial for the development of pyroelectric devices. Around the Curie temperature, as the excess PbO increased from 0 wt. % to 9 wt. %, PLBZST ceramics' pyroelectric coefficient increased from 1600 μC/m2K to 4000 μC/m2K, and the figure of merit increased from 40 x 10-5 Pa-0.5 to 140 x 10-5 Pa-0.5 under a 400 V/mm dc field. The largest figure of merit of 200 x 10-5 Pa-0.5, which is about 8 times higher than that of conventional phase transition materials barium strontium titanate (BST), was obtained in PLBZST ceramics with 6 wt. % excess PbO when a 600 V/mm dc bias field was applied. Therefore, improvement of pyroelectric property is beneficial for the development of infrared detectors.

  4. Polarization of antiferroelectric ceramics for pulse capacitors under transient electric field

    Science.gov (United States)

    Xu, Ran; Xu, Zhuo; Feng, Yujun; Wei, Xiaoyong; Tian, Jingjing; Huang, Dong

    2016-06-01

    The polarization of (Pb0.94La0.04)[(Zr0.7Sn0.3)0.87Ti0.13]O3 antiferroelectric (AFE) ceramics under unipolar pulse electric field was studied, and the transient hysteresis loop was achieved. Compared to the traditional quasi-static results, the forward transition field increases and the backward transition field decreases. The forward and backward phase transitions can be deduced in microseconds scale. Under the transient field, the releasable energy density decreases significantly, while the stored energy density changes slightly. Consequently, the efficiency decreases and the declination of energy density under transient situation is verified by the charge-discharge experiment. The above results prove the necessity of the study of the transient behaviors in AFE and the limitation of quasi-static analysis.

  5. The effect of dc bias on the poled states in PNZST antiferroelectric thin films

    International Nuclear Information System (INIS)

    The effect on the polarization of antiferroelectric (AFE) PNZST ((Pb,Nb)(Zr,Sn,Ti)O3) thin films by ε-E (dc bias field) cycles was studied. It was shown that in these films the AFE ordering is destroyed by the application of a dc electrical field bias along the surface normal direction. After removing the dc bias the film relaxes slowly back to the initial AFE state. This phenomenon is dependent on the film thickness. The relaxation time decreases with increasing film thickness. With increasing storage time of the sample after removing the dc bias at room temperature or heat treatment above the Curie temperature, the AFE ordering can return. From the characteristics of hysteresis loops and ε-E behaviours, we can ascertain that this phenomenon could be attributed to the difference in the poled volume at the interfaces between the electrode and the film

  6. Antiferroelectric ordering and relation between HTSC 1-2-3 critical points

    International Nuclear Information System (INIS)

    Zero approximation dielectrical subsystem of yttrium superconductors is considered theoretically. Estimations of energy concentration holes demonstrating space separation of conducting (CuO2) and dielectrical (CuO) subsystems are given. The model assumes, that electrical dipoles whose subsystem is described by using hamiltonian are formed at the shiff of oxygen ion symmetrical position in the orthorombic phase CuO chains. Advantage of antiferroelectrical (AFE) ordering of electrostatically interacting dipoles is shown. Dependence of AFE temperature of phase transition (PT) on value of ion shift is determined. Application of the theoretical curve on the experimental dependence of ion shift on temperature (point of normalization at the beginning of SC transition) provides for the temperature intervals of AFE phase existence

  7. Pressure-induced ferroelectric to antiferroelectric phase transformation in porous PZT95/5 ceramics

    International Nuclear Information System (INIS)

    The hydrostatic pressure-induced ferroelectric to antiferroelectric (FE-AFE) phase transformation of PZT95/5 ceramics was investigated as a function of porosity, pore shape and pore size. FE-AFE phase transformations were more diffuse and occurred at lower hydrostatic pressures with increasing porosity. The porous PZT95/5 ceramics with spherical pores exhibited higher transformation pressures than those with irregular pores. Moreover, FE-AFE phase transformations of porous PZT95/5 ceramics with polydisperse irregular pores were more diffuse than those of porous PZT95/5 ceramics with monodisperse irregular pores. The relation between pore structure and hydrostatic pressure-induced FE-AFE transformation was established according to stress concentration theory. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Direct current field adjustable ferroelectric behaviour in (Pb, Nb)(Zr, Sn, Ti)O3 antiferroelectric thin films

    International Nuclear Information System (INIS)

    (Pb, Nb)(Zr, Sn, Ti)O3 antiferroelectric (AFE) thin films have been fabricated on LaNiO3/Pt/Ti/SiO2/Si wafers using a sol-gel process. The electric field-induced antiferroelectric-to-ferroelectric (AFE-FE) phase transformation behaviour and its dependence on the temperature were examined by investigating the dielectric constant and dielectric loss versus temperature and electrical field. The AFE-FE phase transformation temperature can be adjusted as a function of the DC bias field and the thickness of the thin film. With increasing DC bias field, the FE phase region was enlarged, the AFE-FE transformation temperature shifted to lower temperature, and the ferroelectric-to-paraelectric transformation temperature shifted to higher temperature. With increasing film thickness, the modulation effect of the DC bias field on the AFE-FE phase transformation temperature is increased

  9. Coexistence of ferroelectric and antiferroelectric microregions in the paraelectric phase of NH4H2PO4 (ADP)

    International Nuclear Information System (INIS)

    Ammonium dihydrogen phosphate NH4H2PO4 (ADP) is an antiferroelectric (AFE) compound belonging to the KDP-type family of hydrogen-bonded ferroelectrics. Recent ab initio results have shown that the optimization of the N-H-O bridges in ADP leads to the stabilization of the AFE state over a FE one. However, electron spin probe measurements have suggested that microregions of both phases may coexist above the critical antiferroelectric-paraelectric transition temperature. We have performed first principles studies of the energetics and relative stability of different AFE and FE defects embedded in a paraelectric (PE) matrix of ADP. Our analysis indicates that FE and AFE clusters are stable and may coexist in the PE phase, thus confirming the above suggestion.

  10. Properties of PbLa(Zr,Sn, Ti)O3 ceramics near ferroelectric-antiferroelectric phase boundary

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two chemical compositions PbLa(Zr,Sn, Ti)O3 (PLZST) ceramics near the ferroelectric-anti- ferroelectric (FE/AFE) phase boundary were prepared by a traditional solid-state reaction process. The electrostriction properties under the electric field and the influence of hydrostatic pressure on the phase transition and the dielectric properties of these PLZST ceramics have been studied. Under the AC electric field, the strain of these two samples reached 0.21% and 0.13%, respectively. With increasing pressure, the FE/AFE phase transition temperature of the antiferroelectrics decreased and the antiferroelectric-paraelectric (AFE/PE) phase transition temperature increased, while the ferroelectric-paraelec- tric (FE/PE) phase transition temperature of the ferroelectrics decreased.

  11. Influence of long-range dipolar interactions on the phase stability and hysteresis shapes of ferroelectric and antiferroelectric multilayers

    OpenAIRE

    Mısırlıoğlu, Burç; Misirlioglu, Burc; Pintilie, Lucian; Alexe, Marin; Hesse, Dietrich

    2009-01-01

    Phase transition and field driven hysteresis evolution of a two-dimensional Ising grid consisting of ferroelectric-antiferroelectric multilayers that take into account the long range dipolar interactions were simulated by a Monte-Carlo method. Simulations were carried out for a 1+1 bilayer and a 5+5 superlattice. Phase stabilities of components comprising the structures with an electrostatic-like coupling term were also studied. An electrostatic-like coupling, in the absence of an applied fie...

  12. Antiferroelectric-to-Ferroelectric Switching in CH3NH3PbI3 Perovskite and Its Potential Role in Effective Charge Separation in Perovskite Solar Cells

    Science.gov (United States)

    Sewvandi, Galhenage A.; Hu, Dengwei; Chen, Changdong; Ma, Hao; Kusunose, Takafumi; Tanaka, Yasuhiro; Nakanishi, Shunsuke; Feng, Qi

    2016-08-01

    Perovskite solar cells (PSCs) often suffer from large performance variations which impede to define a clear charge-transfer mechanism. Ferroelectric polarization is measured numerically using CH3NH3PbI3 (M A PbI3 ) pellets to overcome the measurement issues such as pinholes and low uniformity of thickness, etc., with M A PbI3 thin films. M A PbI3 perovskite is an antiferroelectric semiconductor which is different from typical semiconducting materials and ferroelectric materials. The effect of polarization carrier separation on the charge-transfer mechanism in the PSCs is elucidated by using the results of ferroelectric and structural studies on the perovskite. The ferroelectric polarization contributes to an inherent carrier-separation effect and the I - V hysteresis. The ferroelectric and semiconducting synergistic charge-separation effect gives an alternative category of solar cells, ferroelectric semiconductor solar cells. Our findings identify the ferroelectric semiconducting behavior of the perovskite absorber as being significant to the improvement of the ferroelectric PSCs performances in future developments.

  13. The influence of temperature induced phase transition on the energy storage density of anti-ferroelectric ceramics

    International Nuclear Information System (INIS)

    Anti-ferroelectric (AFE) composite ceramics of (Pb0.858Ba0.1La0.02Y0.008)(Zr0.65Sn0.3Ti0.05)O3-(Pb0.97La0.02)(Zr0.9Sn0.05 Ti0.05)O3 (PBLYZST-PLZST) were fabricated by the conventional solid-state sintering process (CS), the glass-aided sintering (GAS), and the spark plasma sintering (SPS), respectively. The influence of the temperature induced phase transition on the phase structure, hysteresis loops, and energy storage properties of the composite ceramics were investigated in detail. The measured results of X-ray diffraction demonstrate that the composite ceramics exhibit the perovskite phases and small amounts of non-functional pyrochlore phases. Compared with the CS process, the GAS and SPS processes are proven more helpful to suppress the diffusion behaviors between the PBLYZST and PLZST phases according to the field emission scanning electron microscopy, thereby being able to improve the contribution of PBLYZST phase to the temperature stability of the orthogonal AFE phase. When the ambient temperature rises from 25 °C to 125 °C, CS and GAS samples have undergone a phase transition from orthorhombic AFE phase to tetragonal AFE phase, which results in a sharp decline in the energy storage density. However, the phase transition temperature of SPS samples is higher than 125 °C, and the energy storage density only slightly decreases due to the disorder of material microstructure caused by the high temperature. As a result, the SPS composite ceramics obtain a recoverable high energy storage density of 6.46 J/cm3 and the excellent temperature stability of the energy storage density of 1.16 × 10−2 J/°C·cm3, which is 1.29 × 10−2 J/°C·cm3 lower than that of CS samples and about 0.43 times as that of GAS samples

  14. The influence of temperature induced phase transition on the energy storage density of anti-ferroelectric ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jinqiao; Zhang, Ling; Xie, Bing; Jiang, Shenglin, E-mail: nanx1013@163.com [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-09-28

    Anti-ferroelectric (AFE) composite ceramics of (Pb{sub 0.858}Ba{sub 0.1}La{sub 0.02}Y{sub 0.008})(Zr{sub 0.65}Sn{sub 0.3}Ti{sub 0.05})O{sub 3}-(Pb{sub 0.97}La{sub 0.02})(Zr{sub 0.9}Sn{sub 0.05} Ti{sub 0.05})O{sub 3} (PBLYZST-PLZST) were fabricated by the conventional solid-state sintering process (CS), the glass-aided sintering (GAS), and the spark plasma sintering (SPS), respectively. The influence of the temperature induced phase transition on the phase structure, hysteresis loops, and energy storage properties of the composite ceramics were investigated in detail. The measured results of X-ray diffraction demonstrate that the composite ceramics exhibit the perovskite phases and small amounts of non-functional pyrochlore phases. Compared with the CS process, the GAS and SPS processes are proven more helpful to suppress the diffusion behaviors between the PBLYZST and PLZST phases according to the field emission scanning electron microscopy, thereby being able to improve the contribution of PBLYZST phase to the temperature stability of the orthogonal AFE phase. When the ambient temperature rises from 25 °C to 125 °C, CS and GAS samples have undergone a phase transition from orthorhombic AFE phase to tetragonal AFE phase, which results in a sharp decline in the energy storage density. However, the phase transition temperature of SPS samples is higher than 125 °C, and the energy storage density only slightly decreases due to the disorder of material microstructure caused by the high temperature. As a result, the SPS composite ceramics obtain a recoverable high energy storage density of 6.46 J/cm{sup 3} and the excellent temperature stability of the energy storage density of 1.16 × 10{sup −2} J/°C·cm{sup 3}, which is 1.29 × 10{sup −2} J/°C·cm{sup 3} lower than that of CS samples and about 0.43 times as that of GAS samples.

  15. Piezoelectric softening in ferroelectrics: Ferroelectric versus antiferroelectric PbZr1 -xTixO3

    Science.gov (United States)

    Cordero, F.; Craciun, F.; Trequattrini, F.; Galassi, C.

    2016-05-01

    The traditional derivation of the elastic anomalies associated with ferroelectric (FE) phase transitions in the framework of the Landau theory is combined with the piezoelectric constitutive relations instead of being explicitly carried out with a definite expression of the FE part of the free energy. In this manner it is shown that the softening within the FE phase is of electrostrictive and hence piezoelectric origin. Such a piezoelectric softening may be canceled by the better known piezoelectric stiffening, when the piezoelectric charges formed during the vibration are accompanied by the depolarization field, as for example in Brillouin scattering experiments. It is therefore possible to evaluate the average piezoelectric coupling from the usual elastic measurements of unpoled ceramics, where the piezoelectric stiffening does not occur. As experimental validation, we present new measurements on Zr-rich lead zirconate titanate (PZT), where the FE phase transforms into antiferroelectric on cooling or doping with La, and a comparison of existing measurements made on FE PZT with low frequency and Brillouin scattering experiments.

  16. Temperature-dependent dielectric and energy-storage properties of Pb(Zr,Sn,Ti)O3 antiferroelectric bulk ceramics

    OpenAIRE

    Xuefeng Chen; Zhen Liu(Pittsburgh Particle physics, Astrophysics, and Cosmology Center, Department of Physics and Astronomy, University of Pittsburgh, 3941 O’Hara St., Pittsburgh, PA 15260, U.S.A.); Chenhong Xu; Fei Cao; Genshui Wang; Xianlin Dong

    2016-01-01

    The dielectric and energy-storage properties of Pb0.99Nb0.02[(Zr0.60Sn0.40)0.95Ti0.05]0.98O3 (PNZST) bulk ceramics near the antiferroelectric (AFE)-ferroelectric (FE) phase boundary are investigated as a function of temperature. Three characteristic temperatures T0, TC, T2 are obtained from the dielectric temperature spectrum. At different temperature regions (below T0, between T0 and TC, and above TC), three types of hysteresis loops are observed as square double loop, slim loop and linear l...

  17. Genuine driving voltage on polarization fatigue in (Pb,La)(Zr,Ti)O3 antiferroelectric thin films

    OpenAIRE

    Geng, Wenping; Lou, Xiaojie; Xu, Jianghong; Zhang, Fuping; Yang LIU; Dkhil, Brahim; Ren, Xiaobing; Zhang, Ming; HE Hongliang

    2013-01-01

    The polarization fatigue in (Pb0.97La0.02)(Zr0.95Ti0.05)O3 (PLZT) antiferroelectric thin films deposited onto silicon wafers is studied by investigating the effect of the peak/average/effective cycling voltage through varying the waveform of the electrical excitation. Interestingly, it is found that the fatigue endurance of the film is determined by the effective voltage of the external driving excitation rather than by the peak or average voltages. Our results can be well explained in the fr...

  18. Investigation of electric field-induced antiferroelectric to ferroelectric phase transition and phase stability of PLZST ceramics

    International Nuclear Information System (INIS)

    The authors have prepared antiferroelectric ceramics with compositions of (Pb0.97La0.02) (Zr1-x-ySnyTix)O3 (x = 0.09 or 0.1; 0.16≤y≤0.38) near antiferroelectric (AFE) tetragonal-ferroelectric (FE) rhombohedral morphotropic phase boundary. The effects of Sn content on electric field-induced AFE→FE switching field Ec, double-hysteresis-loop width ΔE, and temperature-induced FE→AFE phase transition temperature TFE, AFE→paraelectric (PE) transition temperature Tc are investigated. At constant Ti content x, both TEF and Tc decrease with increase of Sn content y. Electric hysteresis loop measurement demonstrates an increase of Ec and decrease of ΔE when Sn content y increase. Furthermore, the authors also find that Ec and ΔE are related with TFE and Tc. In situ X-ray diffraction under dc bias field shows that symmetry changes from tetragonal phase to rhombohedral phase with an increase of c axis, and an increase of lattice volume

  19. Influence of ionic conductivity on in-phase and anti-phase motions of antiferroelectric liquid crystals

    International Nuclear Information System (INIS)

    The in-phase and anti-phase motions of antiferroelectric liquid crystals were changed due to the influence of charge density associated with the layer modulation modifying the elastic behaviour. The elastic constant was changed because of the coupling between charge density variation and variation of azimuthal angle (ϕ). We obtained theoretically a modified elastic constant depending on the variation of charge density in both in-phase and anti-phase motions. The theoretically elastic constant decreases with the increase of the coupling coefficient between charge density and in-phase azimuthal angle (ϕa). We theoretically accounted the dependence of dielectric strength for both relaxations depending on the effective elastic constant influenced by the presence of charge density and discussed the results with experimental observations

  20. Antiferroelectric Thin-Film Capacitors with High Energy-Storage Densities, Low Energy Losses, and Fast Discharge Times.

    Science.gov (United States)

    Ahn, Chang Won; Amarsanaa, Gantsooj; Won, Sung Sik; Chae, Song A; Lee, Dae Su; Kim, Ill Won

    2015-12-01

    We demonstrate a capacitor with high energy densities, low energy losses, fast discharge times, and high temperature stabilities, based on Pb(0.97)Y(0.02)[(Zr(0.6)Sn(0.4))(0.925)Ti(0.075)]O3 (PYZST) antiferroelectric thin-films. PYZST thin-films exhibited a high recoverable energy density of U(reco) = 21.0 J/cm(3) with a high energy-storage efficiency of η = 91.9% under an electric field of 1300 kV/cm, providing faster microsecond discharge times than those of commercial polypropylene capacitors. Moreover, PYZST thin-films exhibited high temperature stabilities with regard to their energy-storage properties over temperatures ranging from room temperature to 100 °C and also exhibited strong charge-discharge fatigue endurance up to 1 × 10(7) cycles. PMID:26606502

  1. Electric field induced metastable ferroelectric phase and its behavior in (Pb, La)(Zr, Sn, Ti)O3 antiferroelectric single crystal near morphotropic phase boundary

    International Nuclear Information System (INIS)

    Antiferroelectric (AFE) (Pb, La)(Zr, Sn, Ti)O3 (PLZST) single crystal with composition near morphotropic phase boundary has been grown and studied. X-ray diffraction analysis and electrical properties reveal coexistence of antiferroelectric/ferroelectric (FE) phases, with the AFE phase dominated at room temperature. Temperature-dependent polarization and strain measurements indicate that the AFE phase can be induced into a metastable FE phase by electric field. The FE phase can be maintained in a wide temperature range above room temperature and recovers to AFE phase around a critical temperature of 90 °C, accompanied with remarkable change in field-induced strain. The strain at 90 °C (∼0.50%) is ten times larger than that at room temperature (∼0.04%), which makes the PLZST single crystal a promising candidate for thermal switch and actuator application

  2. Anomalous polarization in the antiferroelectric-ferroelectric phase coexistence state in PbZrO3-Bi(Mg1/2Ti1/2)O3

    International Nuclear Information System (INIS)

    The ferroelectric system (1−x)PbZrO3-(x)Bi(Mg1/2Ti1/2)O3 has been investigated as a function of composition, temperature, and electric field by x-ray powder diffraction, dielectric, and ferroelectric measurements. Within the solubility limit (x ∼ 0.25), the system evolves from an orthorhombic-antiferroelectric to rhombohedral-ferroelectric state through a phase coexistence region. The highest polarization was found not for the composition exhibiting a pure ferroelectric state, but for a composition x = 0.15 exhibiting ferroelectric + antiferroelectric phase coexistence close to the rhombohedral phase boundary. Electric poling of the equilibrium two-phase state led to irreversible enhancement in the rhombohedral phase fraction suggesting that the enhanced polarization is related to the enhanced polarizability of the lattice due to first order criticality as in ferroelectric-ferroelectric morphotropic phase boundary systems

  3. Global and local structural variations near the antiferroelectric regime in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Thangavelu, Karthik [Advanced Functional Materials Laboratory, Department of Physics, Indian Institute of Technology Hyderabad, ODF-Campus-502205 (India); Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, ODF-Campus-502205 (India); Rayaprol, S. [UGC-DAE CSR Mumbai Centre, BARC Campus, Mumbai - 400085 (India); Siruguri, V. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India); Sastry, P. U.; Asthana, Saket, E-mail: asthanas@iith.ac.in

    2015-06-24

    Rietveld refinement of neutron and x-ray diffraction data of Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} shows R3c phase stabilization at room temperature. The intermediate antiferroelectric region between 180°C to 280°C exhibits phase coexistence i.e R3c + Pnma, along with decrease in octahedral tilt angle and increase in unit cell volume. The local structural changes observed from Raman scattering in the A-O, Ti-O and TiO{sub 6} phonon modes favor the global structural variation. A possible antiparallel cation displacement due to Pnma phase formation leads to the origin of antiferroelectric ordering in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}.

  4. Global and local structural variations near the antiferroelectric regime in Na0.5Bi0.5TiO3

    International Nuclear Information System (INIS)

    Rietveld refinement of neutron and x-ray diffraction data of Na0.5Bi0.5TiO3 shows R3c phase stabilization at room temperature. The intermediate antiferroelectric region between 180°C to 280°C exhibits phase coexistence i.e R3c + Pnma, along with decrease in octahedral tilt angle and increase in unit cell volume. The local structural changes observed from Raman scattering in the A-O, Ti-O and TiO6 phonon modes favor the global structural variation. A possible antiparallel cation displacement due to Pnma phase formation leads to the origin of antiferroelectric ordering in Na0.5Bi0.5TiO3

  5. Terahertz and Infrared Studies of Antiferroelectric Phase Transition in Multiferroic Bi_0.85Nd_0.15FeO_3

    OpenAIRE

    Goian, V.; Kamba, S.; Greicius, S.; Nuzhnyy, D.; Karimi, S.; Reaney, I.M.

    2011-01-01

    High-frequency dielectric studies of Bi_0.85Nd_0.15FeO_3 ceramics performed betweeen 100 and 900 K reveal hardening of most polar phonons on cooling below antiferroelectric phase transition, which occurs near 600 K. Moreover, a strong THz dielectric relaxation is seen in paraelectric phase. Its relaxation frequency softens on cooling towards Tc ~ 600 K, its dielectric strength simultaneously decreases and finaly the relaxation disappears from the spectra below 450 K. Both phonon and dielectri...

  6. Study of phase transitions in antiferroelectric PbZrO3 and PbHfO3 crystals by acoustic emission method

    International Nuclear Information System (INIS)

    Features of mechanical agreement of ferroelectric (FE) and antiferroelectric (AFE) phases under their phase transition into one another and to paraelectric (PE) phase in PbZr2O3 and PbHfO3 crystals are investigated. Analysis of results of measurements by acoustic emission method has shown that PbZrO3 crystal undergoes two phase transitions in the following sequence: AFE - 210 deg C - FE - 222 deg C - PE; AFE1-163 deg C - AFE2 - 200.5 deg C - PE - for PbHfO3 crystal

  7. High energy storage density performance of Ba, Sr-modified lead lanthanum zirconate titanate stannate antiferroelectric ceramics

    International Nuclear Information System (INIS)

    Graphical abstract: Polarization hysteresis (P–E) loops of the (Pb0.85Ba0.08Sr0.03La0.03) (Zr0.74Sn0.22Ti0.04) samples: (a) measured at different applied electric-field and (b) measured at different temperatures is shown. It is typical antiferroelectrics whose remnant polarization is zero. As the remnant polarization of AFE is small and the ceramics are accompanied by the formation of the anti-parallel domain structure, energy stored in PLZST can be effectively released. Thus we calculated the energy density from the P–E loop and obtained the power density was up to 1.2 J/cm3 at 55 °C, and at 45 °C the energy density was ∼1.24 J/cm3. As usual, for bulk ceramics, the switching between the AFE and FE states occurs at lower field. This value is much higher than that reported previously for the PLZT bulk ceramic (0.4 J/cm3). - Highlights: • Ba2+, Sr2+ co-doping caused the Tc of PLZST moved to the lower temperature (Tc ≈ 40 °C). • The ΔE was so smaller, EAF ≈ 90 kV/cm and EFA ≈ 85 kV/cm. • Ba, Sr co-doped PLZST ceramic exhibited slanted P–E loops with a large breakdown field (100 kV/cm). • A high energy density was up to 1.2 J/cm3. - Abstract: (Pb0.85Ba0.08Sr0.03La0.03)(Zr0.74Sn0.22Ti0.04) (Ba, Sr co-doped PLZST) co-doping antiferroelectric (AFE) ceramics with orthorhombic perovskite structure were prepared by the traditional solid state reaction process. It was observed that the doping of barium and strontium caused the Curie temperature of PLZST move to the lower temperature (Tc ≈ 40 °C). Ba, Sr co-doped PLZST AFE ceramics exhibited excellent electrical properties, the AFE to ferroelectric (FE) transition occurred at field EAF ≈ 90 kV/cm, and the transition from FE to AFE occurred at EFA ≈ 85 kV/cm. The maximum relative permittivity was about 4800, occurring at a field near the AFE to FE transition point, with a dielectric loss of 0.006. The samples exhibited small ΔE and slanted hysteresis loops with a large breakdown field of 100 k

  8. Antiferroelectric Nature of CH3NH3PbI3‑xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells

    Science.gov (United States)

    Sewvandi, Galhenage A.; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi

    2016-07-01

    Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3‑xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3‑xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation.

  9. The kinetics of the local compositional changes at the ferroelectric-antiferroelectric interphase boundaries in lead-lanthanum titanate-zirconate solid solutions

    International Nuclear Information System (INIS)

    The process of local decomposition of lead-lanthanum zirconate-titanate solid solution in the vicinity of the interphase boundaries separating domains of coexisting ferroelectric and antiferroelectric phases has been investigated. The kinetics of the local decomposition of the solid solution containing 6 at.% La, 73 at.% Zr, and 27 at.% Ti in the process of ageing of samples quenched down to room temperature from the paraelectric phase is studied. The mechanisms that define the kinetics of the process of attainment of the equilibrium state of coexisting domains of ferroelectric and antiferroelectric phases are analysed. It is demonstrated that there are two main mechanisms determining the kinetics of establishing of the equilibrium inhomogeneous chemical composition of a solid solution. The slower mechanism is determined by the diffusion of the oxygen vacancies, the nonequilibrium concentration of which was created during the annealing at the temperatures above the Curie temperature. The faster process is determined by the cation diffusion caused by the local mechanical stresses in the vicinity of the interphase boundaries. The equilibrium structure establishes during a time interval of not less than 120 h

  10. Antiferroelectric Nature of CH3NH3PbI3-xClx Perovskite and Its Implication for Charge Separation in Perovskite Solar Cells.

    Science.gov (United States)

    Sewvandi, Galhenage A; Kodera, Kei; Ma, Hao; Nakanishi, Shunsuke; Feng, Qi

    2016-01-01

    Perovskite solar cells (PSCs) have been attracted scientific interest due to high performance. Some researchers have suggested anomalous behavior of PSCs to the polarizations due to the ion migration or ferroelectric behavior. Experimental results and theoretical calculations have suggested the possibility of ferroelectricity in organic-inorganic perovskite. However, still no studies have been concretely discarded the ferroelectric nature of perovskite absorbers in PSCs. Hysteresis of P-E (polarization-electric field) loops is an important evidence to confirm the ferroelectricity. In this study, P-E loop measurements, in-depth structural study, analyses of dielectric behavior and the phase transitions of CH3NH3PbI3-xClx perovskite were carried out and investigated. The results suggest that CH3NH3PbI3-xClx perovskite is in an antiferroelectric phase at room temperature. The antiferroelectric phase can be switched to ferroelectric phase by the poling treatment and exhibits ferroelectric-like hysteresis P-E loops and dielectric behavior around room temperature; namely, the perovskite can generate a ferroelectric polarization under PSCs operating conditions. Furthermore, we also discuss the implications of ferroelectric polarization on PSCs charge separation. PMID:27468802

  11. Enhanced energy storage behaviors in free-standing antiferroelectric Pb(Zr0.95Ti0.05)O3 thin membranes

    Science.gov (United States)

    Zuo, Zheng-Hu; Zhan, Qing-Feng; Chen, Bin; Yang, Hua-Li; Liu, Yi-Wei; Liu, Lu-Ping; Xie, Ya-Li; Li, Run-Wei

    2016-08-01

    Free-standing antiferroelectric Pb(Zr0.95Ti0.05)O3 (PZT(95/5)) thin film is fabricated on 200-nm-thick Pt foil by using pulsed laser deposition. X-ray diffraction patterns indicate that free-standing PZT(95/5) film possesses an a-axis preferred orientation. The critical electric field for the 300-nm-thick free-standing PZT(95/5) film transiting from antiferroelectric to ferroelectric phases is increased to 770 kV/cm, but its saturation polarization remains almost unchanged as compared with that of the substrate-clamped PZT(95/5) film. The energy storage density and energy efficiency of the substrate-clamped PZT(95/5) film are 6.49 J/cm3 and 54.5%, respectively. In contrast, after removing the substrate, the energy storage density and energy efficiency of the free-standing PZT(95/5) film are enhanced up to 17.45 J/cm3 and 67.9%, respectively. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374312, 51401230, and 51522105) and the Fund for Ningbo Municipal Science and Technology Innovation Team, China (Grant No. 2015B11001).

  12. Electron Emission from Ferroelectric/Antiferroelectric Cathodes Excited by Short High-Voltage Pulses

    CERN Document Server

    Benedek, G; Handerek, J; Riege, H

    1997-01-01

    Un-prepoled Lead Zirconate Titanate Lanthanum doped-PLZT ferroelectric cathodes have emitted intense current pulses under the action of a high voltage pulse of typically 8 kV/cm for PLZT of 8/65/35 composition and 25 kV/cm for PLZT of 4/95/5 composition. In the experiments described in this paper, the exciting electric field applied to the sample is directed from the rear surface towards the emitting surface. The resulting emission is due to an initial field emission from the metal of the grid deposited over the emitting surface with the consequent plasma formation and the switching of ferroelectric domains. These electrons may be emitted directly form the crystal or from the plasma. This emission requires the material in ferroelectric phase. In fact, PLZT cathodes of the 8/65/35 type, that is with high Titanium content, showing ferroelectric-paraelectric phase sequence, emit at room temperature, while PLZT cathodes of the 4/95/5 type, that is with low Titanium content, having antiferro-ferro-paraelectric pha...

  13. The structural origin of the antiferroelectric properties and relaxor behavior of Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dorcet, V. [Laboratoire de Cristallographie et Sciences des Materiaux, CRISMAT-CNRS UMR 6508, 6 Bd. du Marechal Juin, F-14050, Caen Cedex (France)], E-mail: vincent.dorcet@ensicaen.fr; Trolliard, G. [Laboratoire Sciences des Procedes Ceramiques et des Traitements de Surface, SPCTS-CNRS-UMR-6638, 123 Av. Albert Thomas, F-87060, Limoges Cedex (France); Boullay, P. [Laboratoire de Cristallographie et Sciences des Materiaux, CRISMAT-CNRS UMR 6508, 6 Bd. du Marechal Juin, F-14050, Caen Cedex (France)

    2009-06-15

    This work presents a study of Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} (NBT) by transmission electron microscopy in the 20-370 {sup o}C temperature range. A new orthorhombic intermediate phase between the rhombohedral and the tetragonal phases is proposed to account for the occurrence of 1/2 (oee) superstructure spots. The phase transition from the rhombohedral to the orthorhombic phase occurs via a modulated phase formed by rhombohedral blocks and orthorhombic sheets. It is shown that these latter represent rhombohedral (0 1 0) twin planes. The modulated phase is proposed to explain the antiferroelectric and relaxor behaviors of NBT.

  14. Composition-dependent electrical properties of (Pb, La)(Zr, Sn, Ti)O3 antiferroelectric thin films grown on platinum-buffered silicon substrates

    International Nuclear Information System (INIS)

    (Pb, La)(Zr, Sn, Ti)O3 (PLZST) antiferroelectric (AFE) thin films with different compositions were deposited on Pt-buffered silicon wafers by the sol-gel process. The phase structure and the surface morphology of the PLZST AFE thin films were analysed by XRD and SEM, respectively. The electric field induced AFE-to-ferroelectric (AFE-FE) phase transformation behaviour of the PLZST thin films was examined by polarization versus field (P-E) and relative permittivity versus field (εr-E) measurements, with emphasis placed on composition-dependent phase switching field. The phase switching current was investigated as a function of a gradually changed dc electric field. Furthermore, the effect of the composition of the PLZST thin films on the Curie temperature (Tc) was also studied in detail

  15. Direct evidence of an incommensurate phase in NaNbO3 and its implication in NaNbO3-based lead-free antiferroelectrics

    International Nuclear Information System (INIS)

    Hot-stage in situ transmission electron microscopy was employed to investigate the temperature-induced complex sequence of phase transitions in NaNbO3 polycrystalline. In addition to the commonly recognized P (Pbma) → R (Pmnm) → S (Pnmm) phase transitions, incommensurate phases were observed to exist in P and R phase regions. The former (in the P → R transition region) is coincident with a diffused dielectric peak appearing at ∼170 °C, and the latter (in the R → S transition region) serves as an intermediate structure to bridge the two sub-phases in the R phase region. The incommensurate phase in the P phase region can be inferred from the polarization current density and differential dielectric permittivity anomalies, and it provides the bridge structure during the electric field-induced polarization reversal and antiferroelectric-to-ferroelectric transition in NaNbO3 solid solutions

  16. Field-induced phase switching and electrically driven strains in sol-gel derived antiferroelectric (Pb,Nb)(Zr,Sn,Ti)O3 thin layers

    International Nuclear Information System (INIS)

    Tin-modified lead zirconate titanate thin layers were prepared by a sol-gel method. A room- temperature antiferroelectric (AFE) phase composition Pb0.99Nb0.02[(Zr0.58Sn0.42)0.96Ti0.04] 0.98O3 was prepared and examined for weak- and high-field dielectric properties as a function of temperature, with emphasis on field-induced AFE-ferroelectric (FE) switching characteristics. Thin layers processed with a lead oxide cover coat were found to be free of any secondary phases and showed improved properties. Room-temperature values of dielectric constant K'=390 and saturation polarization Ps=20 μC/cm2 were obtained with field-induced strains up to 0.15% in submicron grain structures. copyright 1995 American Institute of Physics

  17. Domain configuration changes under electric field-induced antiferroelectric-ferroelectric phase transitions in NaNbO3-based ceramics

    International Nuclear Information System (INIS)

    We recently developed a feasible crystal chemistry strategy to stabilize the antiferroelectricity in NaNbO3 through a chemical substitution to decrease the tolerance factor and increase the average electronegativity of the system [Shimizu et al., Dalton Trans. 44, 10763 (2015) and Guo et al., J. Appl. Phys. 117, 214103 (2015)]. Two novel lead-free antiferroelectric (AFE) solid solutions, (1-x)NaNbO3-xCaZrO3 and (1-x)NaNbO3-xSrZrO3, have been found to exhibit the double polarization hysteresis typical of a reversible AFE ↔ ferroelectric (FE) phase transition. In this study, as demonstrated by (1-x)NaNbO3-xCaZrO3 system, the influence of chemical modification and electrical poling on the AFE/FE phase stability was investigated, primarily focusing on the microstructural and crystallographic evolutions. Together with the macroscopic polarization hysteresis measurements, a well-demonstrated structure-property relationship was presented. It was found that the CaZrO3 substitution into NaNbO3 can effectively destabilize the FE Q phase and correspondingly lead to a spontaneous reverting to AFE P phase. In contrast to the reversible AFE ↔ FE phase transition, the domain morphology evolution exhibits irreversible nature with a growing process of the orientational domains after applying electric field. Moreover, a multiple-zone axes electron diffraction map of P and Q phases has been summarized and is believed to be an efficient diagram to determine the AFE/FE nature of the NaNbO3-based systems

  18. Anomalous polarization in the antiferroelectric-ferroelectric phase coexistence state in PbZrO{sub 3}-Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Vadlamani, Bhaskar Sravan; Lalitha, K. V.; Ranjan, Rajeev, E-mail: rajeev@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science Bangalore 560012 (India)

    2013-12-21

    The ferroelectric system (1−x)PbZrO{sub 3}-(x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3} has been investigated as a function of composition, temperature, and electric field by x-ray powder diffraction, dielectric, and ferroelectric measurements. Within the solubility limit (x ∼ 0.25), the system evolves from an orthorhombic-antiferroelectric to rhombohedral-ferroelectric state through a phase coexistence region. The highest polarization was found not for the composition exhibiting a pure ferroelectric state, but for a composition x = 0.15 exhibiting ferroelectric + antiferroelectric phase coexistence close to the rhombohedral phase boundary. Electric poling of the equilibrium two-phase state led to irreversible enhancement in the rhombohedral phase fraction suggesting that the enhanced polarization is related to the enhanced polarizability of the lattice due to first order criticality as in ferroelectric-ferroelectric morphotropic phase boundary systems.

  19. Terahertz and infrared studies of antiferroelectric phase transition in multiferroic Bi.sub.0.85./sub.Nd.sub.0.15./sub.FeO.sub.3./sub..

    Czech Academy of Sciences Publication Activity Database

    Goian, Veronica; Kamba, Stanislav; Greicius, S.; Nuzhnyy, Dmitry; Karimi, S.; Reaney, I. M.

    2011-01-01

    Roč. 110, č. 7 (2011), 074112/1-074112/5. ISSN 0021-8979 R&D Projects: GA ČR GD202/09/H041; GA ČR(CZ) GA202/09/0682 Grant ostatní: GA UK(CZ) SVV-2011-263303 Institutional research plan: CEZ:AV0Z10100520 Keywords : multiferroics * infrared and THz spectroscopy * phonons * antiferroelectrics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.168, year: 2011

  20. Phase diagram and incommensurate antiferroelectric structure in (Pb1−1.5xLax)(Zr0.42Sn0.40Ti0.18)O3 ceramics discovered by band-to-band optical transitions

    International Nuclear Information System (INIS)

    Optical properties and phase transitions of (Pb1−1.5xLax)(Zr0.42Sn0.40Ti0.18)O3 (PLZST 100x/42/40/18) ceramics with different compositions have been investigated by temperature dependent spectroscopic ellipsometry. Two interband critical points (Ecp1 and Ecp2) located at about 3.9 and 5.1 eV can be obtained by fitting standard line shapes to the second derivatives of the complex dielectric functions. Based on the band-to-band transitions, the phase diagram of PLZST ceramics can be well presented. Moreover, a peculiar incommensurate antiferroelectric state has been found to exist above the temperature of the normal commensurate antiferroelectric tetragonal structure. It can be stable below Curie temperature, evolving slowly with decreasing temperature towards the commensurate structure, which is due to strong pinning of incommensurate domain walls. The phenomena can result from a competition between ferroelectric ordering and antiferroelectric ordering caused by the lanthanum modification.

  1. Electric response in the antiferroelectric crystal of 4,4′-di-t-butyl-2,2′-bipyridyl with chloranilic acid

    International Nuclear Information System (INIS)

    Highlights: • The semiconducting properties of the crystals were disclosed in the organic complex. • Dielectric relaxation and dc conductivity were investigated. • Activation energy for the thermally activated processes of the σdc was estimated. • The effect of hydrogen bonds on the mechanism of the phase transition and the electric properties of the crystal was discussed. - Abstract: The electric response was analyzed in the vicinity of the structural phase transition at 412 K in the single crystals of 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (chloranilic acid, CLA) with 4,4′-di-t-butyl-2,2′-bipyridyl (dtBBP). The dielectric permittivity of the complex measured along the b direction between 300 and 440 K and at frequencies ranging from 500 Hz to 2 MHz indicates two phenomena. At low frequencies, dielectric losses are ascribed to the electric conductivity of the crystal, while at high frequencies, to the dielectric relaxation described by means of the Cole–Cole relationship. The parameters of the dielectric response: the relaxation time, τ, the dielectric increment, εο − ε∞, and the distribution parameter of the relaxation time, α, were estimated and analyzed. The low-temperature structure of the crystals indicates the antiferroelectric arrangement of the supramolecular hydrogen bonds. The dielectric results also presented for the deuterated crystals of dtBBP·CLA proved that the dynamics of protons in the hydrogen bonds are responsible for the mechanism of phase transition

  2. Dielectric relaxation behavior in antiferroelectric metal organic framework [(CH3)2NH2][Fe(III)Fe(II)(HCOO)6] single crystals.

    Science.gov (United States)

    Sieradzki, A; Pawlus, S; Tripathy, S N; Gągor, A; Ciupa, A; Mączka, M; Paluch, M

    2016-03-16

    The fundamental aspects of the relaxation dynamics in niccolite-type, mixed valence metal-organic framework, multiferroic [(CH3)2NH2][Fe(3+)Fe(2+)(HCOO)6] single crystals have been reported using dielectric relaxation spectroscopy covering eight decades in frequency (10(-2) ≤ f ≤ 10(6)) in the temperature range 120 K ≤ T ≤ 250 K. The compound shows antiferroelectric to paraelectric phase transition near T = 154 K with the relaxor nature of electric ordering. The temperature dependent dielectric response in modulus representation indicates three relaxation processes within the experimental window. The variable range hopping model of small polarons explains the bulk non-Debye type conductivity relaxation. The fastest relaxation with activation energy Ea = 0.17 eV is related to progressive freezing of the reorientation motions of DMA(+) cations. X-ray diffraction data revealed that complete freezing of orientational and translational motions of DMA(+) cations occurs well below phase transition temperature. These experimental observations are fundamentally important for the theoretical explanation of relaxation dynamics in niccolite-type metal-organic frameworks. PMID:26936014

  3. An anti-ferroelectric gated Landau transistor to achieve sub-60 mV/dec switching at low voltage and high speed

    Science.gov (United States)

    Karda, Kamal; Jain, Ankit; Mouli, Chandra; Alam, Muhammad Ashraful

    2015-04-01

    Landau field effect transistors promise to lower the power-dissipation of integrated circuits (ICs) by reducing the subthreshold swing (S) below the Boltzmann limit of 60 mV/dec. The key idea is to replace the classical gate insulator with dielectrics that exhibit negative capacitance (NC) associated with double-well energy landscape, for example, ferroelectrics (FE), air-gap capacitors, or a combination thereof. Indeed, S is dramatically reduced, constrained only by the limits of hysteresis-free operation. Unfortunately, the following limitations apply (i) the need for capacitance matching constrains steep S only to the small subthreshold region for FE based negative capacitance field effect transistor (NCFET) and requires an insulator too thick for sub-20 nm scaling; (ii) the kinetics of mechanical switching for airgap based NCFET obviate high-speed operation; and (iii) the lattice mismatch between the substrate and the dielectric makes defect-free integration difficult. In this article, we demonstrate that a FET integrated with 10 nm HfO2-based anti-ferroelectric and FE hetero stack would achieve ultralow S with ON-current ( Io n) at par with classical transistors at significantly lower voltage and would simplify integration. Our results address the well-known challenges/criticisms of classical Landau transistors, thereby, making them technology relevant for modern ICs.

  4. Experiment and theory of Pb(In1/2Nb1/2)O3. Antiferroelectric, ferroelectric, or relaxor state depending on perovskite B-site randomness

    International Nuclear Information System (INIS)

    We review the recent progress in our understanding of the effect of B-site randomness on Pb(In1/2Nb1/2)O3 (PIN) from the experimental and theoretical viewpoints. PIN is one of the ideal systems for investigating the effect of perovskite B-site randomness on relaxor formation, because it can be in the antiferroelectric (AFE), ferroelectric (FE), or relaxor state depending on B-site randomness. Lattice dynamics measured in ordered and disordered PINs indicates the existence of FE instability regardless of the B-site randomness of PIN. AFE is stabilized when the B-site is spatially ordered, overwhelming FE instability. The hidden FE state starts to appear as B-site randomness becomes stronger and suppresses AFE instability. Ultimately, the randomness competes with the development of FE regions and blocks long-range FE ordering, which yields polar nanoregions (PNRs) resulting in relaxor behavior. In order to investigate the interesting behavior of PIN, we constructed a minimal model that includes dipolar interaction and easy-axis anisotropy which depends on B-site randomness. The results from Monte Carlo simulations show that the model well reproduces the phase diagram and dielectric constant of PIN qualitatively. (author)

  5. Local stabilisation of polar order at charged antiphase boundaries in antiferroelectric (Bi0.85Nd0.15(Ti0.1Fe0.9O3

    Directory of Open Access Journals (Sweden)

    Ian MacLaren

    2013-08-01

    Full Text Available Observation of an unusual, negatively-charged antiphase boundary in (Bi0.85Nd0.15(Ti0.1Fe0.9O3 is reported. Aberration corrected scanning transmission electron microscopy is used to establish the full three dimensional structure of this boundary including O-ion positions to ∼±10 pm. The charged antiphase boundary stabilises tetragonally distorted regions with a strong polar ordering to either side of the boundary, with a characteristic length scale determined by the excess charge trapped at the boundary. Far away from the boundary the crystal relaxes into the well-known Nd-stabilised antiferroelectric phase.

  6. Control of values of temperature hysteresis and dielectric anomaly diffuseness in a range of ferro-antiferroelectric phase transition in ceramics of PbZr1-xTixO3 (0.03 ≤ x ≤ 0.05)

    International Nuclear Information System (INIS)

    One has revealed possibility to change reversibly the values of temperature hysteresis and of dielectric anomaly diffuseness relevant to the transition between the antiferroelectric (AFE) and the ferroelectric (FE) phases in PbZr1-xTixO-3 ceramics (0.03≤x≤0.05) by varying of the heating and the cooling temperatures in the course of temperature cycling. The obtained results show that the AFE-FE transition in PbZr1-xTixO-3 ceramics is the first-order diffused phase transition

  7. Electric response in the antiferroelectric crystal of 4,4′-di-t-butyl-2,2′-bipyridyl with chloranilic acid

    Energy Technology Data Exchange (ETDEWEB)

    Rok, M., E-mail: magdalena.rok@chem.uni.wroc.pl; Piecha-Bisiorek, A.; Szklarz, P.; Bator, G.; Sobczyk, L.

    2015-05-01

    Highlights: • The semiconducting properties of the crystals were disclosed in the organic complex. • Dielectric relaxation and dc conductivity were investigated. • Activation energy for the thermally activated processes of the σ{sub dc} was estimated. • The effect of hydrogen bonds on the mechanism of the phase transition and the electric properties of the crystal was discussed. - Abstract: The electric response was analyzed in the vicinity of the structural phase transition at 412 K in the single crystals of 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (chloranilic acid, CLA) with 4,4′-di-t-butyl-2,2′-bipyridyl (dtBBP). The dielectric permittivity of the complex measured along the b direction between 300 and 440 K and at frequencies ranging from 500 Hz to 2 MHz indicates two phenomena. At low frequencies, dielectric losses are ascribed to the electric conductivity of the crystal, while at high frequencies, to the dielectric relaxation described by means of the Cole–Cole relationship. The parameters of the dielectric response: the relaxation time, τ, the dielectric increment, ε{sub ο} − ε{sub ∞}, and the distribution parameter of the relaxation time, α, were estimated and analyzed. The low-temperature structure of the crystals indicates the antiferroelectric arrangement of the supramolecular hydrogen bonds. The dielectric results also presented for the deuterated crystals of dtBBP·CLA proved that the dynamics of protons in the hydrogen bonds are responsible for the mechanism of phase transition.

  8. Temperature-dependent stability of energy storage properties of Pb0.97La0.02(Zr0.58Sn0.335Ti0.085)O3 antiferroelectric ceramics for pulse power capacitors

    International Nuclear Information System (INIS)

    The dielectric properties and electrical hysteresis behaviors of Pb0.97La0.02(Zr0.58Sn0.335Ti0.085)O3 antiferroelectric (AFE) ceramics were investigated in this work with an emphasis on energy storage properties. Three phase transition points can be detected as temperature increases. AFE and paraelectric phases are found to coexist from 100 °C to 170 °C. The room temperature recoverable energy density is 1.37 J/cm3 at 8.6 kV/mm. With increasing temperature (from 20 °C to 100 °C) and frequency (from 0.01 to 100 Hz) under 8.6 kV/mm, the variation of recoverable energy density was less than 15%, all higher than 1.2 J/cm3. All the corresponding energy efficiencies were no less than 75%. The high energy density, high energy efficiency, and their weak dependence on temperature and frequency during a wide scope indicate that these antiferroelectric ceramics are quite promising to be used for pulse power capacitors applications

  9. Structure-property relations at the antiferroelectric/ferroelectric phase boundary in undoped and La doped Pb(Zr,Ti)O3

    International Nuclear Information System (INIS)

    The Pb1-3x/2Lax(Zr1-yTiy)O3 (PLZT) phase diagram in the vicinity of the antiferroelectric/ferroelectric phase boundary (AFE/FE) originally developed by Haertling and Land (1971) has been investigated using X-ray diffraction (XRD) transmission electron microscopy (TEM), relative permittivity as a function of temperature and polarisation versus field (hysteresis measurements). In general, the phase diagram has been confirmed but a new explanation for the diffraction data across the AFE/FE boundary based on octahedral tilt configurations has been proposed. 1/2{hk0}p superlattice reflections were consistently present in p, p and p electron diffraction patterns from the ferroelectric phase in all samples except PZT 70/30 and were suggested to arise from antiparallel displacements of the Pb ions rather than in-phase octahedral rotations. 1/2{hkl}p reflections were present in all samples and were considered to arise from antiphase rotations of the octahedra. All FE compositions were rhombohedral by XRD, the AFE PZ and PZT phases wen orthorhombic and La doped AFE compositions were tetragonal with an incommensurate modulation along [11-bar0]p and [110]p directions (the incommensurate AFE phase has been ascribed an a0a0c- tilt system consistent with the macroscopic symmetry (tetragonal) and with electron diffraction data). However, the presence of 1/2{hk0}p reflections in electron diffraction patterns from the FE phase close to the AFE phase boundary suggested locally lower symmetry than rhombohedral, possibly monoclinic. The following tilt configurations have been proposed to explain the observed diffraction data: PZT: a0b-b- (AFE) to a-b-b- (a∼b, FE close to AFE phase) and a-a-a- FE low temperature phase. PLZT: a0a0c- (AFE incommensurate) to a-b-b- (a∼b, FE close to AFE phase) and a-a-a- (FE low temperature) Ferroelectric hysteresis and permittivity versus temperature measurements were consistent with those reported by Haertling and Land (1971). (author)

  10. Phase diagram and incommensurate antiferroelectric structure in (Pb{sub 1−1.5x}La{sub x})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} ceramics discovered by band-to-band optical transitions

    Energy Technology Data Exchange (ETDEWEB)

    Ding, X. J.; Xu, L. P.; Hu, Z. G., E-mail: zghu@ee.ecnu.edu.cn; Chu, J. H. [Key Laboratory of Polar Materials and Devices, Department of Electronic Engineering, East China Normal University, Ministry of Education, Shanghai 200241 (China); Chen, X. F.; Wang, G. S.; Dong, X. L. [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2014-09-29

    Optical properties and phase transitions of (Pb{sub 1−1.5x}La{sub x})(Zr{sub 0.42}Sn{sub 0.40}Ti{sub 0.18})O{sub 3} (PLZST 100x/42/40/18) ceramics with different compositions have been investigated by temperature dependent spectroscopic ellipsometry. Two interband critical points (E{sub cp1} and E{sub cp2}) located at about 3.9 and 5.1 eV can be obtained by fitting standard line shapes to the second derivatives of the complex dielectric functions. Based on the band-to-band transitions, the phase diagram of PLZST ceramics can be well presented. Moreover, a peculiar incommensurate antiferroelectric state has been found to exist above the temperature of the normal commensurate antiferroelectric tetragonal structure. It can be stable below Curie temperature, evolving slowly with decreasing temperature towards the commensurate structure, which is due to strong pinning of incommensurate domain walls. The phenomena can result from a competition between ferroelectric ordering and antiferroelectric ordering caused by the lanthanum modification.

  11. Effect of B-site randomness on the antiferroelectric/relaxor nature of the ground state: inelastic X-ray scattering study of Pb(In1/2Nb1/2)O3

    International Nuclear Information System (INIS)

    Pb(In1/2Nb1/2)O3 (PIN) can be antiferroelectric (AFE), ferroelectric (FE) or a relaxor depending upon the perovskite B-site randomness. In order to clarify the effect of B-site randomness, we studied the dynamics of ordered PIN without B-site randomness (O-PIN, AFE), which will give us a clear picture of the AFE/relaxor nature of the ground state due to B-site randomness. The quasielastic (QE) scattering shows a critical slowing down near the Γ-point and the transverse acoustic (TA) mode shows a softening trend at a finite wavenumber position (not at the Γ-point) towards the AFE phase transition temperature (TN ∼ 450 K). On the other hand, the transverse optic (TO) mode shows a softening near the Γ-point toward low temperature with no clear anomaly at TN. These results indicate that the AFE phase transition is associated with the TA mode and the origin of the QE scattering while a ferroelectric correlation exists behind the AFE ordering. The effect of B-site randomness is finally discussed on the basis of the results.

  12. Leakage current characteristics and dielectric breakdown of antiferroelectric Pb0.92La0.08Zr0.95Ti0.05O3 film capacitors grown on metal foils

    International Nuclear Information System (INIS)

    We have grown crack-free antiferroelectric (AFE) Pb0.92La0.08Zr0.95Ti0.05O3 (PLZT) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, we applied a conductive buffer layer of lanthanum nickel oxide (LNO) on the nickel foil by chemical solution deposition prior to the PLZT deposition. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be prepared at high temperatures in air. With the AFE PLZT deposited on LNO-buffered Ni foils, we observed field-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, EAF = 260 kV cm-1, and the reverse phase transition field, EFA = 220 kV cm-1, were measured at room temperature on a ∼1.15 μm thick PLZT film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were ∼530 and ∼740, respectively, with dielectric loss -9 A cm-2 at room temperature under 87 kV cm-1 applied field. The breakdown behaviour of the AFE PLZT film-on-foil capacitors was studied by Weibull analysis. The mean breakdown time decreased exponentially with increasing applied field. The mean breakdown time was over 610 s when a field of 1.26 MV cm-1 was applied to a 1.15 μm thick AFE PLZT film-on-foil capacitor.

  13. 组份变化对{ PZST陶瓷反铁电-铁电相变的影响%Effects of Compositional Variations on Antiferroelectric-Ferroelectric Phase Transition of PZST Ceramics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Phase structures,properties and critical parameters of field-induced phase transitions of PZST ceramics near ferroelectric(FE)-antiferroelectric(AFE) phase boundary were studied as a function of composition and temperature.The electric field-induced FE state can maintain metastable state below the critical temperature TFE-AFE after electric field is removed.As temperature increases,the metastable FE state changes to AFE state at TFE-AFE.As Ti content increases,the structure of unpoled PZST ceramics changes from tetragonal AFE phase to rhombohedral FE phase,dielectric constant maximum max and transition temperature TFE-AFE increase,switching field EAFE-FE and EFE-AFE decrease.The forward switching field EAFE-FE and hysteresis E were observed to be dependent on TFE-AFE and Tc,respectively,and EAFE-FE and E decreased with an associated increasing in TFE-AFE and decreasing in Tc.%对FE-AFE相界附近PZST陶瓷结构、性能及场诱相变临界参数随组份和温度的变化进行了研究.在相变临界温度TFE-AFE以下,被电场诱导出的铁电态在撤去电场后以亚稳态形式存在,随着温度升高,亚稳铁电态在此温度转变为反铁电态.随着Ti含量的增加,样品由四方反铁电相穿越相界转变为三方铁电相,介电常数峰值max增大;同时亚稳铁电态反铁电态相变温度TFE-AFE上升,电场诱导的AFE相变临界参数EAFE-FE、EFE-AFE减小.实验中发现EAFE-FE和 E分别与TFE-AFE和Tc相关,随着TEF-AFE的升高和Tc的降低,EAEF-FE和 E相应减小.

  14. Metastable states in ferroelectric materials

    International Nuclear Information System (INIS)

    Results of investigating phase transitions in ferroelectrics are generalized. It is experimentally and theoretically shown that between ferroelectrical (FE) and antiferroelectrical (AFE) phases in a number of cases there is a wide range, where FE state may be irreversibly induced by magnetic field. On the basis of experimental and theoretical P-T diagrams metastable character of FE phase in this range is proved. Interaction of FE and AFE type ordering phases coexisting below Kurie point determines anomalies of many physical properties in ferroelectrics

  15. Enhanced energy storage performance in (Pb{sub 0.858}Ba{sub 0.1}La{sub 0.02}Y{sub 0.008})(Zr{sub 0.65}Sn{sub 0.3}Ti{sub 0.05})O{sub 3}-(Pb{sub 0.97}La{sub 0.02})(Zr{sub 0.9}Sn{sub 0.05} Ti{sub 0.05})O{sub 3} anti-ferroelectric composite ceramics by Spark Plasma Sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ling; Jiang, Shenglin; Fan, Baoyan; Zhang, Guangzu

    2015-02-15

    Highlights: • The composite ceramics have much higher energy storage density than pure anti-ferroelectrics. • SPS process can suppress the diffusion behavior between the tetragonal and orthorhombic phases. • A high recoverable energy storage density of 6.40 J/cm{sup 3} was obtained in the composite ceramics. - Abstract: Anti-ferroelectric composite ceramics of (Pb{sub 0.858}Ba{sub 0.1}La{sub 0.02}Y{sub 0.008})(Zr{sub 0.65}Sn{sub 0.3}Ti{sub 0.05})O{sub 3}-(Pb{sub 0.97}La{sub 0.02})(Zr{sub 0.9}Sn{sub 0.05} Ti{sub 0.05})O{sub 3} (PBLYZST-PLZST) have been fabricated by Spark Plasma Sintering (SPS) method. The effect of SPS process on phase structure, anti-ferroelectric and energy storage properties of the composites has been investigated in detail. The X-ray diffraction, field emission scanning electron microscopy and energy-dispersive spectrometry analysis illustrate that the composites are composed of tetragonal perovskite, orthorhombic perovskite and small amount of non-functional pyrochlore phases. Compared with conventional solid-state sintering (CS) process, SPS process is helpful to suppress the diffusion behavior between the tetragonal PBLYZST and orthorhombic PLZST phases, and thereby improve the contribution of PLZST phase to the FE-to-AFE phase transition electric field (E{sub A}) of the composites. As a result, the SPS composite ceramics possess a considerable E{sub A} of 162 kV/cm and a high recoverable energy storage density valued 6.40 J/cm{sup 3} which is 1.75 J/cm{sup 3} higher than that of the CS samples and about 2.3 times as that of the PBLYZST ceramics.

  16. Electric response of Pb{sub 0.99}[(Zr{sub 0.90}Sn{sub 0.10}){sub 0.968}Ti{sub 0.032}]{sub 0.98}Nb{sub 0.02}O{sub 3} ceramics to the shock-wave-induced ferroelectric-to-antiferroelectric phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Dongdong, E-mail: jiangdongeast@163.com [Electronic Materials Research Laboratory, Xi' an Jiaotong University, Xi' an 710049 (China) and International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China) and National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, P.O. Box 919-111, Mianyang 621900 (China); Zhang Na; Feng Yujun [Electronic Materials Research Laboratory, Xi' an Jiaotong University, Xi' an 710049 (China); International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an 710049 (China); Du Jinmei; Gu Yan [National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP, P.O. Box 919-111, Mianyang 621900 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Shock wave induces the FE-to-AFE phase transition in PbNb(Zr,Sn,Ti)O{sub 3}. Black-Right-Pointing-Pointer Depoling current due to phase transition depends on shock pressure and load resistance. Black-Right-Pointing-Pointer Shock pressure promotes the phase transition in short-circuit case. Black-Right-Pointing-Pointer Increasing load resistance decreases the released charge. - Abstract: Shock-wave-enforced ferroelectric (FE)-to-antiferroelectric (AFE) phase transition releases a large electrical polarization, having application in pulse power technology. In the present work, the depoling currents under shock wave compression were investigated in Pb{sub 0.99}[(Zr{sub 0.90}Sn{sub 0.10}){sub 0.968}Ti{sub 0.032}]{sub 0.98}Nb{sub 0.02}O{sub 3} (PZST) ceramics with composition close to the FE/AFE phase boundary. Shock wave was generated by gas-gun and propagated in a direction perpendicular to the remanent polarization. It was found that the shock pressure promoted the phase transition under the short-circuit condition. The shock pressure dependence of the released charge was associated with the evolution of FE-to-AFE phase transition. The onset of phase transition was about 0.40 GPa and complete transformation occurred at 1.23 GPa. However, the released charge decreased with increasing load resistance. The reason may be that the electric field suppresses the phase transition in uncompressed zone and/or shock induces conductivity in compressed zone. Results lay the foundation for application of PZST ceramics in shock-activated power supply.

  17. Electric response of Pb0.99[(Zr0.90Sn0.10)0.968Ti0.032]0.98Nb0.02O3 ceramics to the shock-wave-induced ferroelectric-to-antiferroelectric phase transition

    International Nuclear Information System (INIS)

    Highlights: ► Shock wave induces the FE-to-AFE phase transition in PbNb(Zr,Sn,Ti)O3. ► Depoling current due to phase transition depends on shock pressure and load resistance. ► Shock pressure promotes the phase transition in short-circuit case. ► Increasing load resistance decreases the released charge. - Abstract: Shock-wave-enforced ferroelectric (FE)-to-antiferroelectric (AFE) phase transition releases a large electrical polarization, having application in pulse power technology. In the present work, the depoling currents under shock wave compression were investigated in Pb0.99[(Zr0.90Sn0.10)0.968Ti0.032]0.98Nb0.02O3 (PZST) ceramics with composition close to the FE/AFE phase boundary. Shock wave was generated by gas-gun and propagated in a direction perpendicular to the remanent polarization. It was found that the shock pressure promoted the phase transition under the short-circuit condition. The shock pressure dependence of the released charge was associated with the evolution of FE-to-AFE phase transition. The onset of phase transition was about 0.40 GPa and complete transformation occurred at 1.23 GPa. However, the released charge decreased with increasing load resistance. The reason may be that the electric field suppresses the phase transition in uncompressed zone and/or shock induces conductivity in compressed zone. Results lay the foundation for application of PZST ceramics in shock-activated power supply.

  18. Study of structure and dielectric properties of Pb(Sn,Zr,Ti)O3 solid solutions

    International Nuclear Information System (INIS)

    Results of investigation of Pb(Sn,Zr,Ti)O3 solid solutions are presented. It is shown that in the above-mentioned solid solutions at room temperature ferroelectric and antiferroelectric phases coexist. In this range dielectric properties have clearly pronounced anomalies. Phase transition from ferroelectric to antiferroelectric state of polarized materials under the effect of hydrostatic pressure occurs spasmodically. The value of ferroelectric-antiferroelectric phase transition depends on titanium concentration

  19. Light sensitive achiral polar polymeric composites

    Science.gov (United States)

    González-Henríquez, C. M.; Soto-Bustamante, E. A.; Vergara-Toloza, R. O.; Haase, W.

    2011-07-01

    The occurrence of antiferroelectric phenomenon in achiral composites composed of azo-benzene containing liquid crystals was observed. Some of the composites evidenced typical antiferroelectric polarization hysteresis loop in the mesophase, showing bilayer smectic C 2 mesophases with some interdigitation grade at the layer interface in a broad temperature range. Surprisingly composites of similar structure developed pyroelectricity but not switchable states. This new class of antiferroelectric materials is also capable of producing E-Z photoisomerization making them good candidates for energy harvesting.

  20. Sustainable materials

    Science.gov (United States)

    Allwood, Julian M.

    2016-01-01

    Materials influence every aspect of the energy system; therefore, as well as developing new materials for energy generation, materials scientists should engage in public debate about the limitations of future innovations and the conservation of existing materials.

  1. Structural and orientational properties of the ferro, antiferroelectric, and re-entrant smectic C.sup.*./sup. phases of ZLL7/.sup.*./sup. by deuterium NMR and other experimental techniques

    Czech Academy of Sciences Publication Activity Database

    Catalano, D.; Domenici, V.; Marini, A.; Veracini, C.A.; Bubnov, Alexej; Glogarová, Milada

    2006-01-01

    Roč. 100, - (2006), s. 16459-16470. ISSN 1520-6106 R&D Projects: GA ČR GP202/03/P011; GA ČR GA202/05/0431 Grant ostatní: European Project(XE) COST D14 WG15 Institutional research plan: CEZ:AV0Z10100520 Keywords : NMR * deuterated materials * liquid crystal * polar mesophases * x-ray structural properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.115, year: 2006

  2. Understanding Materials

    Science.gov (United States)

    Katsioloudis, Petros J.

    2010-01-01

    Almost everything people have ever done has involved materials. Historical evidence indicates that "engineered materials" have been available and utilized for the benefit of humankind since the Neolithic period, beginning about 10,000 BC. Some of these materials have been in existence for thousands of years. At first, materials consisted of wood,…

  3. Materials Development

    Institute of Scientific and Technical Information of China (English)

    Brian Tomlinson

    2005-01-01

    @@ Introduction Materials development is both a field of study and a practical undertaking. As a field it studies the principles and procedures of the design, implementation and evaluation and adaptation of language teaching materials, by teachers for their own classrooms and by materials writers for sale or distribution. Ideally these two aspects of materials development are interactive in that the theoretical studies inform and are informed by the development and use of classroom materials (e. g. Tomlinson 1998c).

  4. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  5. Functional materials

    International Nuclear Information System (INIS)

    It is a compilation of chapters written by active researchers and offer information and critical insights about semiconducting materials and devices, dielectric and ferroelectric materials, magnetic materials, composites and other functional materials. In the book, the functional materials are discussed from the mixed valences and stoichiometry points of view, to understand the structural evolution and transformation of different material systems - in particular, the role played by crystal structures in property control of functional materials using advanced characterization techniques. The book examines the properties, soft-chemistry preparations, electronic structures and crystal structures of transition and rare earth metals and their oxides. The book presents a strong argument that functional materials system is the future direction of the multidisciplinary research involving physics, chemistry, materials science and electrical engineering, with emphasis on device applications. Papers relevant to INIS are indexed separately

  6. Contrast Materials

    Science.gov (United States)

    ... adverse reaction, you should tell your doctor about: allergies to contrast materials, food, drugs, dyes, preservatives, or animals medications ... These include: previous adverse reactions to iodine-based contrast materials history of ... disease dehydration sickle cell anemia , polycythemia and ...

  7. Flourinated material

    OpenAIRE

    Bozukova, Dimitriya; Jérôme, Christine; Pagnoulle, Christophe

    2009-01-01

    This invention relates to a method for modifying the surface of a material for use with a biological sample or tissue comprising the steps of providing a material having a surface which comprises reactive-functional groups; providing fluorinated molecules having reactive-functional groups complimentary to those on the material surface; using wet chemistry to attach the fluorinated molecules to the surface of the material by reacting the reactive-functional groups of the implant with the compl...

  8. Materials Engineering

    OpenAIRE

    Fidancevska, Emilija; Srebrenkoska, Vineta

    2013-01-01

    The material presented in this book is the last part from the five books series which are resulte of the aforementioned project. Sustainable development, pariculary for industry was the base for developing of these educative materials. Part of the contents presented in the previous books covered the temas which generally are connected with sustainable development, but this book coveres the types of materials in general and the management of the waste materials. The nowdays f...

  9. Composite Materials

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro...

  10. Materials development

    International Nuclear Information System (INIS)

    Objective of the materials program is the development of a structural material for the MSBR primary circuit which is resistant to irradiation embrittlement and intergranular attack by fission products. The bulk of the work was done on the development and study of modified Hastelloy N (Ti, Nb), including its interaction with salt and fission Te. Materials (Ta-10 percent W, Mo, graphite) are also being tested for corrosion resistance at 600 and 7000C to Bi--Li for use in fuel processing

  11. Engineering materials

    OpenAIRE

    Kumaraswamy, Mohan

    2002-01-01

    One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data of the Engineering Materials such as concrete, metals and wood. Portland Cement Concrete is a particulate composite consisting of a continuous binder phase, the cementitious matrix and a dispersed particulate phase, the aggregates. Metals as construction material are an important construction material. They possess characteristics such as strength, stiffness, toughness and ductili...

  12. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael;

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  13. Materializing Ethnography

    OpenAIRE

    Geismar, H.; Horst, H. A.

    2004-01-01

    The articles in this volume were originally presented in a panel entitled ‘Material Methodologies’ at the American Anthropological Association meeting in New Orleans (November 2002). The panel was devised to tie together theoretical advances in the study of the material with the creative possibilities of fieldwork practices. Through detailed ethnographic discussion, we highlighted the ways in which a focus on a specifically material world enabled us to discover new perspecti...

  14. Materializing ideas

    DEFF Research Database (Denmark)

    Strandvad, Sara Malou

    2011-01-01

    Based on a qualitative study of development processes in the Danish film industry, this article sketches a socio-material perspective for analysing the production of culture. Whereas previous studies of cultural production have identified social factors in cultural production, this article sets out...... while it is becoming materialized....

  15. Scintillator material

    International Nuclear Information System (INIS)

    A scintillator material for detection and quantitative determination of ionizing radiation is discussed consisting of an acridone dissolved in a fluid or solid medium. Solvent mixtures with at least one protogenic component or polymers and copolymers are used. The scintillator material is distinguished by an excellent stability at high energy doses

  16. Composite material

    Energy Technology Data Exchange (ETDEWEB)

    Hutchens, Stacy A. (Knoxville, TN); Woodward, Jonathan (Solihull, GB); Evans, Barbara R. (Oak Ridge, TN); O' Neill, Hugh M. (Knoxville, TN)

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  17. Composite material

    Science.gov (United States)

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O'Neill, Hugh M.

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  18. Thermoluminescent materials

    International Nuclear Information System (INIS)

    Thermoluminescence is the emission of light from substances when they are heated. This phenomena is observed for many synthetic and natural substances. These thermoluminescent materials must be ionic crystals, covalent crystals, and molecular crystals - an insulator or a semiconductor, but metals do not exhibit luminescent properties because they could not storage radiation energy. Most research has been devoted to the discovery and development of materials suitable for thermoluminescence dosemeters, and some phosphors are used routinely in dosimetric applications. But for other purposes, many interesting materials have been suggested and investigated. (author)

  19. Polymer Materials

    Institute of Scientific and Technical Information of China (English)

    Charles C. Han; DONG Jinyong; NIU Hui; CHENG He; HUANG Ye; ZHENG Jianfen; XU Shanshan

    2011-01-01

    @@ Since the second half of the 20th century, polymer materials have already become an essential part of our daily life.The use of polymeric materials has already exceeded that of metals and ceramics in terms of volume and is intimately connected to our clothing, food, household use, transportation, and medical needs.Meanwhile it also brought some recycle and environmental problems.In the 21 st century, human beings are facing ever increasing challenges on environmental protection, energy shortage, and health-medical problems, which have made even higher demand on polymer materials due to its light weight, flexibility and high functionality.

  20. Utopian Materialities

    DEFF Research Database (Denmark)

    Elgaard-Jensen, Torben

    2004-01-01

    In various ways, this paper makes the counter-intuitive claim that the utopian and the material are thoroughlyinterdependent, rather than worlds apart. First, through a reading of Thomas More's Utopia, it is argued thatUtopia is the product of particular kinds of relations, rather than merely a...... detachment from the known world.Second, the utopianism of a new economy firm is examined. It is argued that the physical set-up of the firm -in particular the distribution of tables and chairs - evoke a number of alternatives to ordinary work practice.In this way the materialities of the firm are crucial to...... its persuasive image of being the office of the future.The notion that utopia is achieved through material arrangements is finally related to the analysis of facts andfictions in ANT. It is argued, that even though Utopias are neither fact nor fiction, they are both material andeffective on the...

  1. Encountering Materiality

    DEFF Research Database (Denmark)

    Svabo, Connie

    2016-01-01

    DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016.......DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016....

  2. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia;

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  3. Video material

    OpenAIRE

    Mark Miodownik

    2004-01-01

    The scanning electron microscopy (SEM) images of microelectromechanical systems in motion pictures were discussed. Computer-generated special effects were used on materials like silicon, polyurethanes and wood for giving special effects in the movies. It was found that the use of digital video was bringing science and entertainment industry closer to form a new fusion of art and science. It was suggested that more sophisticated models of materials behavior were required to render realistic ef...

  4. Propulsion materials

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Edward J. [U.S. Dept. of Energy, Washington, D.C. (United States); Sullivan, Rogelio A. [U.S. Dept. of Energy, Washington, D.C. (United States); Gibbs, Jerry L. [U.S. Dept. of Energy, Washington, D.C. (United States)

    2008-01-01

    The Department of Energy’s (DOE’s) Office of Vehicle Technologies (OVT) is pleased to introduce the FY 2007 Annual Progress Report for the Propulsion Materials Research and Development Program. Together with DOE national laboratories and in partnership with private industry and universities across the United States, the program continues to engage in research and development (R&D) that provides enabling materials technology for fuel-efficient and environmentally friendly commercial and passenger vehicles.

  5. Photostrictive materials

    OpenAIRE

    Kundys, B.

    2015-01-01

    Light-matter interactions that lead to nonthermal changes in size of the sample constitute a photostrictive effect in many compounds. The photostriction phenomenon was observed in four main groups of materials, ferroelectrics, polar, and non-polar semiconductors, as well as in organic-based materials that are reviewed here. The key mechanisms of photostriction and its dependence on several parameters and perturbations are assessed. The major literature of the photostriction is surveyed, and t...

  6. Magnetostrictive materials

    International Nuclear Information System (INIS)

    The paper has been prepared on the basis of literature survey covering last 10 years. The article contains concise overview of the effect of magnetostriction and related effects such as Villarie effect, Young modulus change effect, Widemann and Birkhausen effects. Magnetostrictive materials (MM) covert reversibly magnetic energy into energy of elastic deformation. Traditional, as well as newest magnetostrictive materials, exhibiting effect of giant magnetostriction, e.g. containing rare earth metals (Tb,Dy) Terphenol-D, have been discussed. Interesting new groups of materials appear to be hybrid systems, which combine properties of magnetostrictive and magnetic shape memory materials. Processing methods of MM comprise rapid solidification of liquid alloy, monocrystallization, directional crystallization and powder metallurgy. Potential application areas of MM are generally related to their use as sensors and actuators. MM find applications in sonar devices, seismic sensors, geological tomography, hydraulic valves, sensors of motion, force and magnetic field, and many others. Interesting field of MM applications is related to systems for health monitoring of composite materials. Directions for further research in the field of MM should consider development of new materials having lower anisotropy and hysteresis, and development of a new technologies e.g. thin magnetostrictive films. (author)

  7. Shielding material

    International Nuclear Information System (INIS)

    The present invention effectively utilizes iron reinforced concrete wastes generated upon dismantling of concretes of nuclear facilities, to provide shielding material. That is, at least one of members selected from the group consisting of iron rods in iron-reinforced concretes and, regenerated aggregates regenerated from concrete wastes upon dismantling is charged in a predetermined mold. Cement pastes or cement mortars are charged therein, and solidified, cured and released from the mold. With such procedures, a block-formed shielding materials made of precast concretes can be obtained. In this case, the cements including much water of crystallization are used. Since iron reinforcing dusts and iron reinforcing dust chips are contained in the shielding materials, a great γ-ray shielding effect can be obtained. Further, since cements containing a great amount of water of crystallization are used, a great neutron shielding effect can be obtained. (I.S.)

  8. Virtual materiality

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    There are two questions that feed the curiosity of this paper: a theoretical question connected to the conceptualization of materiality across the real/virtual divide and an empirical question connected to the understanding of virtual experiences in children’s lives when studied in relation to...... recounts of them and 3. the consumption of other media products like movies, reality shows, YouTube videos etc. How do we theorize ‘matter’ in such dimensions? Is it possible to theorize virtual matter as ‘materiality’ in line with any real life materiality? What conceptualization will help us understand...... is a field that begs for new theorizing and new analytical tools. (Søndergaard 2008, 2009a) It is a field that deals with children’s individual and collective processes of becoming, of materializing and of entering in and as agentic part(ner)s of the human and non-human world. But current theoretical...

  9. Layered materials

    Science.gov (United States)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and

  10. Photovaltic materials

    CERN Document Server

    Bube, R H

    1998-01-01

    Research and development of photovoltaic solar cells is playing an ever larger practical role in energy supply and ecological conservation all over the world. Many materials science problems are encountered in understanding existing solar cells and the development of more efficient, less costly, and more stable cells. This important and timely book provides a historical overview, but concentrates primarily on exciting developments in the last decade. It describes the properties of the materials that play an important role in photovoltaic applications, the solar cell structures in which they ar

  11. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  12. Touching Materiality

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2012-01-01

    Dripping ink pens, colourful paint on skin, vegetables pots on a school roof. In interviews with three generations of former school pupils, memories of material objects bore a relation to everyday school life in the past. Interwoven, these objects entered the memorising processes, taking the inte...

  13. Emerging Materiality

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Breinbjerg, Morten; Pold, Søren

    2009-01-01

    The authors examine how materiality emerges from complex chains of mediation in creative software use. The primarily theoretical argument is inspired and illustrated by interviews with two composers of electronic music. The authors argue that computer mediated activity should not primarily be...

  14. Nuclear materials

    International Nuclear Information System (INIS)

    In 1996, 39 inspections of nuclear materials were performed, 22 of them performed in co-operation with IAEA inspectors. The main content of common inspections with IAEA was the inspection of both fresh and spent fuel in Bohunice NPPs and Mochovce NPPs. During 1996 there were 420 spent fuel assemblies transported from the V-1 and V-2 NPPs units to the interim spent fuel storage and 396 spent fuel assemblies were transported to the Dukovany NPP. Current state of stored spent fuel in the interim spent fuel storage is 4656 fuel assemblies, 4050 of them are Bohunice NPPs assemblies and 606 of them are fuel assemblies which belong to Dukovany NPP. There are 128 spent fuel assemblies stored in A-1 NPP, which are placed in cases of the long-term storage. Inspections of fresh fuel storage in the V-1, V-2 and Mochovce NPPs were performed, as well as spent fuel inspections in the A-1 NPP and in the interim spent fuel storage in Bohunice. From the outcomes of inspections resulted, that the limits and conditions, operating procedures and conditions of nuclear safety were not violated in any ease. There was no extraordinary event at above mentioned equipment during the 1996 and the equipment was reliably operated. NRA SR performed during 1996 eight inspections focused on safety protection of nuclear equipment and nuclear materials, and no significant deficiencies, which could resulted in extraordinary events or violation of nuclear safety were found out. Safety of transportation of fresh fuel, spent fuels, and other materials is discussed. NRA SR performed inspection focused on checking transportation readiness each transportation of the spent nuclear fuel. Serious deficiencies were not found out. Suggested system for treatment of radioactive materials caught at illegal trade is described. An attempt to export 3 radioactive sources in consignment of iron scrap to Italy came about in 1996. The NRA SR continued in co-operation with IAEA on updating IAEA database to illegal

  15. Friction Material Composites Materials Perspective

    CERN Document Server

    Sundarkrishnaa, K L

    2012-01-01

    Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

  16. Materials Science

    Science.gov (United States)

    2003-01-01

    The Materials Science Program is structured so that NASA s headquarters is responsible for the program content and selection, through the Enterprise Scientist, and MSFC provides for implementation of ground and flight programs with a Discipline Scientist and Discipline Manager. The Discipline Working Group of eminent scientists from outside of NASA acts in an advisory capacity and writes the Discipline Document from which the NRA content is derived. The program is reviewed approximately every three years by groups such as the Committee on Microgravity Research, the National Materials Advisory Board, and the OBPR Maximization and Prioritization (ReMaP) Task Force. The flight program has had as many as twenty-six principal investigators (PIs) in flight or flight definition stage, with the numbers of PIs in the future dependent on the results of the ReMaP Task Force and internal reviews. Each project has a NASA-appointed Project Scientist, considered a half-time job, who assists the PI in understanding and preparing for internal reviews such as the Science Concept Review and Requirements Definition Review. The Project Scientist also insures that the PI gets the maximum science support from MSFC, represents the PI to the MSFC community, and collaborates with the Project Manager to insure the project is well-supported and remains vital. Currently available flight equipment includes the Materials Science Research Rack (MSRR-1) and Microgravity Science Glovebox. Ground based projects fall into one or more of several categories. Intellectual Underpinning of Flight Program projects include theoretical studies backed by modeling and computer simulations; bring to maturity new research, often by young researchers, and may include preliminary short duration low gravity experiments in the KC-135 aircraft or drop tube; enable characterization of data sets from previous flights; and provide thermophysical property determinations to aid PIs. Radiation Shielding and preliminary In

  17. Magnetocaloric materials

    Energy Technology Data Exchange (ETDEWEB)

    Jeppesen, Stinus

    2008-10-15

    New and improved magnetocaloric materials are one of the cornerstones in the development of room temperature magnetic refrigeration. Magnetic refrigeration has been used since the 1930ies in cryogenic applications, but has since the discovery of room temperature refrigerants received enormous attention. This Ph.D. work has been mainly concerned with developing a new technique to characterize the magnetocaloric effect (MCE) and using this technique in the investigations on new and improved magnetocaloric materials. For this purpose a novel differential scanning calorimeter (DSC) with applied magnetic fields was developed for measuring heat capacity as function of magnetic field. Measurements using the developed DSC demonstrate a very high sensitivity, fast measurements and good agreement with results obtained by other techniques. Furthermore, two material systems have been described in this work. Both systems take basis in the mixed-valence manganite system La{sub 1-x}Ca{sub x}MnO{sub 3} well known from research on colossal magnetoresistance (CMR). The mixed-valence manganite crystallizes in the perovskite structure of general formula ABO{sub 3}. The first material system is designed to investigate the influence of low level Cu doping on the B-site. Six different samples were prepared with over-stoichiometric compositions La{sub 0.67}Ca{sub 0.33}Mn{sub 1.05}Cu{sub x}O{sub 3}, x=0, 1, 2, 3, 4 and 5%. All compositions crystallized well in the same perovskite structure, but the morphology of the samples changed drastically with doping. Investigation on the magnetocaloric properties revealed that small levels of Cu up to around 3% could improve the magnetocaloric performance of the materials. Furthermore, Cu could be used to tune the temperature interval without deteriorating the MCE, which is a much desired characteristic for potential use in magnetic refrigerators. A less comprehensive part of the work has been concerned with the investigation of doping on the A

  18. Classy material

    OpenAIRE

    Mark Miodownik

    2005-01-01

    The usefulness of glass and it's impact on our culture is discussed. Glass is irreplaceable as our main transparent protection against the wind, rain, heat, and cold, and is therefore, the key to our trains, plains, automobiles, and buildings. The transparency and inertness of glass pushed chemistry forward by allowing color changes of chemical reactions to be measured and gas evolution to be observed, so that glass became the essential material for chemistry. Glass is used by the physicists ...

  19. Prosthesis Material

    Science.gov (United States)

    2004-01-01

    In this photograph, Amputee Amie Bradly uses a NASA-developed prosthesis to paint her fingernails. Derived from foam insulation technology used to protect the Space Shuttle External Tank from excessive heat, FAB/CAD, a subsidiary of the Harshberger Prosthetic and Orthotic Center, utilized the technology to replace the heavy, fragile plaster they used to produce master molds for prosthetics. The new material was lighter, cheaper and easier to manufacture than plaster, resulting in lower costs to the customer.

  20. Material monitoring

    International Nuclear Information System (INIS)

    Waste Reduction Operations Complex (WROC) facilities are located at the Idaho National Engineering Laboratory (INEL). The overall goal for the Pollution Prevention/Waste Minimization Unit is to identify and establish the correct amount of waste generated so that it can be reduced. Quarterly, the INEL Pollution Prevention (P2) Unit compares the projected amount of waste generated per process with the actual amount generated. Examples of waste streams that would be addresses for our facility would include be are not limited to: Maintenance, Upgrades, Office and Scrap Metal. There are three potential sources of this variance: inaccurate identification of those who generate the waste; inaccurate identification of the process that generates the waste; and inaccurate measurement of the actual amount generated. The Materials Monitoring Program was proposed to identify the sources of variance and reduce the variance to an acceptable level. Prior to the implementation of the Material Monitoring Program, all information that was gathered and recorded was done so through an informal estimation of waste generated by various personnel concerned with each processes. Due to the inaccuracy of the prior information gathering system, the Material Monitoring Program was established. The heart of this program consists of two main parts. In the first part potential waste generators provide information on projected waste generation process. In the second part, Maintenance, Office, Scrap Metal and Facility Upgrade wastes from given processes is disposed within the appropriate bin dedicated to that process. The Material Monitoring Program allows for the more accurate gathering of information on the various waste types that are being generated quarterly

  1. Biomedical Materials

    Institute of Scientific and Technical Information of China (English)

    CHANG Jiang; ZHOU Yanling

    2011-01-01

    @@ Biomedical materials, biomaterials for short, is regarded as "any substance or combination of substances, synthetic or natural in origin, which can be used for any period of time, as a whole or as part of a system which treats, augments, or replaces any tissue, organ or function of the body" (Vonrecum & Laberge, 1995).Biomaterials can save lives, relieve suffering and enhance the quality of life for human being.

  2. Plugging material

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Yu.S.; Kravtsov, V.M.; Mavlyutov, M.R.; Spivak, A.I.; Trutnev, G.A.

    1982-01-01

    Plugging material is proposed which includes Portland cement and quartz sand. In order to improve the strength of the stone and sedimentation stability of the cement mud and to guarantee expansion during hardening of the stone in the interval 20-180/sup 0/C, it also contains solid residue of wastes from soda production thermally treated at temperature 850-900/sup 0/C with the following ratio of components (% by mass): Portland cement 60-80, quartz sand 15-20; solid residue of soda production 5-20.

  3. Energy materials

    CERN Document Server

    Bruce, Duncan W; Walton, Richard I

    2011-01-01

    In an age of global industrialisation and population growth, the area of energy is one that is very much in the public consciousness. Fundamental scientific research is recognised as being crucial to delivering solutions to these issues, particularly to yield novel means of providing efficient, ideally recyclable, ways of converting, transporting and delivering energy. This volume considers a selection of the state-of-the-art materials that are being designed to meet some of the energy challenges we face today. Topics are carefully chosen that show how the skill of the synthetic chemist can

  4. Photovoltaic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E.; Joshi, P.; List, F.; Paranthaman, P.; Parish, C.; Wereszczak, A.

    2012-10-15

    The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties including defects, impurities, and grain boundaries affect the solar cell performance. ORNL also has unique processing capabilities to optimize the manufacturing process for fabrication of high efficiency and low cost solar cells. ORNL recently established the Center for Advanced Thin-film Systems (CATS), which contains a suite of optical and electrical characterization equipment specifically focused on solar cell research. Under this project, ORNL made these facilities available to industrial partners who were interested in pursuing collaborative research toward the improvement of their product or manufacturing process. Four specific projects were pursued with industrial partners: Global Solar Energy is a solar industry leader in full scale production manufacturing highly-efficient Copper Indium Gallium diSelenide (CIGS) thin film solar material, cells and products. ORNL worked with GSE to develop a scalable, non-vacuum, solution technique to deposit amorphous or nanocrystalline conducting barrier layers on untextured stainless steel substrates for fabricating high efficiency flexible CIGS PV. Ferro Corporation’s Electronic, Color and Glass Materials (“ECGM”) business unit is currently the world’s largest supplier of metallic contact materials in the crystalline solar cell marketplace. Ferro’s ECGM business unit has been the world's leading supplier of thick film metal pastes to the crystalline silicon PV industry for more than 30 years, and has had operational

  5. PREFACE: Superconducting materials Superconducting materials

    Science.gov (United States)

    Charfi Kaddour, Samia; Singleton, John; Haddad, Sonia

    2011-11-01

    The discovery of superconductivity in 1911 was a great milestone in condensed matter physics. This discovery has resulted in an enormous amount of research activity. Collaboration among chemists and physicists, as well as experimentalists and theoreticians has given rise to very rich physics with significant potential applications ranging from electric power transmission to quantum information. Several superconducting materials have been synthesized. Crucial progress was made in 1987 with the discovery of high temperature superconductivity in copper-based compounds (cuprates) which have revealed new fascinating properties. Innovative theoretical tools have been developed to understand the striking features of cuprates which have remained for three decades the 'blue-eyed boy' for researchers in superconductor physics. The history of superconducting materials has been notably marked by the discovery of other compounds, particularly organic superconductors which despite their low critical temperature continue to attract great interest regarding their exotic properties. Last but not least, the recent observation of superconductivity in iron-based materials (pnictides) has renewed hope in reaching room temperature superconductivity. However, despite intense worldwide studies, several features related to this phenomenon remain unveiled. One of the fundamental key questions is the mechanism by which superconductivity takes place. Superconductors continue to hide their 'secret garden'. The new trends in the physics of superconductivity have been one of the two basic topics of the International Conference on Conducting Materials (ICoCoM2010) held in Sousse,Tunisia on 3-7 November 2010 and organized by the Tunisian Physical Society. The conference was a nice opportunity to bring together participants from multidisciplinary domains in the physics of superconductivity. This special section contains papers submitted by participants who gave an oral contribution at ICoCoM2010

  6. Gas storage materials, including hydrogen storage materials

    Science.gov (United States)

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  7. Geopolymer resin materials, geopolymer materials, and materials produced thereby

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong-Kyun; Medpelli, Dinesh; Ladd, Danielle; Mesgar, Milad

    2016-03-29

    A product formed from a first material including a geopolymer resin material, a geopolymer resin, or a combination thereof by contacting the first material with a fluid and removing at least some of the fluid to yield a product. The first material may be formed by heating and/or aging an initial geopolymer resin material to yield the first material before contacting the first material with the fluid. In some cases, contacting the first material with the fluid breaks up or disintegrates the first material (e.g., in response to contact with the fluid and in the absence of external mechanical stress), thereby forming particles having an external dimension in a range between 1 nm and 2 cm.

  8. The materials physics companion

    CERN Document Server

    Fischer-Cripps, Anthony C

    2014-01-01

    Introduction to Materials Physics: Structure of matter. Solid state physics. Dynamic properties of solids. Dielectric Properties of Materials: Dielectric properties. Ferroelectric and piezoelectric materials. Dielectric breakdown. Applications of dielectrics. Magnetic Properties of Materials: Magnetic properties. Magnetic moment. Spontaneous magnetization. Superconductivity.

  9. Nuclear materials in Japan

    Science.gov (United States)

    2015-03-01

    The incident at Fukushima Daiichi brought materials in the nuclear industry into the spotlight. Nature Materials talks to Tatsuo Shikama, Director of the International Research Centre for Nuclear Materials, Institute for Materials Research, Tohoku University, about the current situation.

  10. Photorefractive Materials and Their Applications 2 Materials

    CERN Document Server

    Günter, Peter

    2007-01-01

    Photorefractive Materials and Their Applications 2: Materials is the second of three volumes within the Springer Series in Optical Sciences. The book gives a comprehensive review of the most important photorefractive materials and discusses the physical properties of organic and inorganic crystals as well as poled polymers. In this volume, photorefractive effects have been investigated at wavelengths covering the UV, visible and near infrared. Researchers in the field and graduate students of solid-state physics and engineering will gain a thorough understanding of the properties of materials in photorefractive applications. The other two volumes are: Photorefractive Materials and Their Applications 1: Basic Effects. Photorefractive Materials and Their Applications 3: Applications.

  11. Investigations on Electronic Materials

    OpenAIRE

    Pugnor, E.; T. Kormány

    1982-01-01

    Electronics has been described as a materials oriented technology. In this sense a short review is given concerning: the connection of materials characterization to the design and processing of electronic components; the most important materials characterization methods used for electronic materials; the strategy of organizing a complete material characterization system for selected electronic components.

  12. Sporty materials uncovered

    OpenAIRE

    Kevin Edwards

    2004-01-01

    Materials in Sports Equipment is a welcome addition to books on materials engineering, says Kevin Edwards. It fills a gap in coverage of the important sports market, where advances in materials can lead to improved performance.

  13. Sporty materials uncovered

    Directory of Open Access Journals (Sweden)

    Kevin Edwards

    2004-03-01

    Full Text Available Materials in Sports Equipment is a welcome addition to books on materials engineering, says Kevin Edwards. It fills a gap in coverage of the important sports market, where advances in materials can lead to improved performance.

  14. Materials for Fusion Applications

    OpenAIRE

    Jiří Matějíček

    2013-01-01

    An overview of materials foreseen for use or already used in fusion devices is given. The operating conditions, material requirements and characteristics of candidate materials in several specific application segments are briefly reviewed. These include: construction materials, electrical insulation, permeation barriers and plasma facing components. Special attention will be paid to the latter and to the issues of plasma-material interaction, materials joining and fuctionally graded interlayers.

  15. Digestive Diseases Materials

    Science.gov (United States)

    ... Image Library Digestive Disease, Nutrition, and Weight-control Materials Healthy eating, physical activity, and weight control materials available from NIDDK's Weight-control Information Network(WIN) ...

  16. High Temperature Materials Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The High Temperature Materials Lab provides the Navy and industry with affordable high temperature materials for advanced propulsion systems. Asset List: Arc Melter...

  17. Fusion materials: insulators and plasma facing materials

    International Nuclear Information System (INIS)

    Insulating materials: surface damage: Oxide materials will be extensively used in ITER in heating and current drive, and diagnostic systems where they will play important roles as electrical insulators, and RF and optical transmission components. These materials will be subjected to neutron and gamma radiation, and additionally to bombardment by low energy ions and neutral particles of energies between eV and keV as a consequence of neutron reactions and related sputtering at vacuum surfaces, as well as ionization and acceleration of the residual gas due to local electric fields. To assess the damage, SiO2 (KS-4V), Al2O3, AlN, and BeO, the main candidate ceramic insulators for ITER were implanted (bombarded) with light ions, and KS-4V and sapphire were also irradiated with electrons. In-situ surface electrical conductivity measurements in high vacuum during implantation or irradiation were carried out. In addition, before and after implantation or irradiation, both optical absorption measurements and SEM X-ray analysis were performed. It was found that the origin of the surface electrical and related optical degradation is radiolytic, i.e. the damage is caused by the electronic excitation induced during material irradiation. Plasma Wall Interaction: In fusion devices, in the region next to high temperature plasma (typically ∼10 keV), material erodes from plasma-facing materials in one location and is transported to other, sometimes remote, locations throughout the device. The transported material may then be deposited on, or implanted into, other materials. If the plasma facing material in a device consists of more than a single element there is a high probability that the composition of the plasma-facing surfaces will evolve over time and may exhibit plasma interaction properties much different from the originally installed material. These plasma-created materials are so - called mixed materials. The creation of mixed-material surfaces will depend on many

  18. Materials and Nanotechnology

    International Nuclear Information System (INIS)

    The Materials and Nanotechnology Program is divided into subprograms in the following areas: Ceramic Materials, Composite Materials, Metallic Materials, Physical / Chemical Characterization and Nanomaterials. The subprograms are further divided in to broad topics in research, development and innovations. Within each topic, several R and D projects are carried out

  19. Tritium breeding materials

    International Nuclear Information System (INIS)

    Tritium breeding materials are essential to the operation of D-T fusion facilities. Both of the present options - solid ceramic breeding materials and liquid metal materials are reviewed with emphasis not only on their attractive features but also on critical materials issues which must be resolved

  20. Materials and Nanotechnology

    International Nuclear Information System (INIS)

    The focus of the Materials and Nanotechnology Program is technology development related to processing, analysis, testing and characterization of materials in general. The Program is divided into subprograms in broad areas such as ceramic, composite and metallic materials as well as characterization of physical and chemical properties of materials

  1. Materials technology. A dictionary

    International Nuclear Information System (INIS)

    The dictionary lists about 3000 terms used in the science and technology of materials, referring to and explaining structure, microstructure and properties, metal and non-metal materials, natural materials, man-made materials and plastics, inorganic materials, composite materials, fabrication and processing methods, the testing of materials and manufactured components, surface treatment methods, tribology, and corrosion, wear and aging. Whenever appropriate, terms of related scientific areas have been included. The terms and explanations are accompanied by diagrams, illustrations and tables, which round up the textual information and facilitate comprehension. (MM)

  2. Materials Analysis and Modeling of Underfill Materials.

    Energy Technology Data Exchange (ETDEWEB)

    Wyatt, Nicholas B [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chambers, Robert S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    The thermal-mechanical properties of three potential underfill candidate materials for PBGA applications are characterized and reported. Two of the materials are a formulations developed at Sandia for underfill applications while the third is a commercial product that utilizes a snap-cure chemistry to drastically reduce cure time. Viscoelastic models were calibrated and fit using the property data collected for one of the Sandia formulated materials. Along with the thermal-mechanical analyses performed, a series of simple bi-material strip tests were conducted to comparatively analyze the relative effects of cure and thermal shrinkage amongst the materials under consideration. Finally, current knowledge gaps as well as questions arising from the present study are identified and a path forward presented.

  3. ON - SITE MATERIAL MANAGEMENT

    OpenAIRE

    Sahil.R.Choure; M.R.Apte

    2015-01-01

    Site material management is a process for controlling field and office activities on construction site related to the materials. The site material management system attempts to insure that the right quality and quantity of materials are appropriately delivered and handled onsite in a timely manner. Planning a nd controlling all of the efforts necessary to ensure that the correct quality and quantity of materials are properly specified in a timely manner and ...

  4. Joining of dissimilar materials

    Science.gov (United States)

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  5. Informing material specification

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Karmon, Ayelet

    2012-01-01

    Architecture is entering a radical rethinking of its material practice. Advancements in material science and more complex models of material simulation as well as the interfaces between design and fabrication are fundamentally changing the way we conceive and design our built environment. This new...... technological platform allows an unprecedented control over the material. Creating direct links between the space of design and the space of fabrication, the idea of the hyper specified material developed in direct response to defined design criteria calls upon a new material practice in which designers of...... artifacts are also designers of materials. In this practice materials are seen as bespoke composites, differentiated and graded, and whose particular detailing is a central part of a projects overall solution. This paper will present a dual investigation into material design as an architectural practice...

  6. Materials research for fusion

    Science.gov (United States)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  7. Materials for breeding blankets

    International Nuclear Information System (INIS)

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified

  8. Methods of materiality

    DEFF Research Database (Denmark)

    Aagaard, Jesper; Matthiesen, Noomi

    2016-01-01

    researchers should start paying attention to the material world (consisting of both human bodies and material objects) and what it means for how people live their lives. It is argued that this can be done by incorporating the concept of material presence to capture embodied and material layers of existence......, and the method of participant observation is suggested as a viable approach to achieve this end. An empirical example of how authority is produced in a parent-teacher conference, not only through language but also through material objects and embodied being, is then presented. The article concludes by...... suggesting practical guidelines for incorporating attention to materiality in qualitative research....

  9. Advanced energy materials

    CERN Document Server

    Tiwari, Ashutosh

    2014-01-01

    An essential resource for scientists designing new energy materials for the vast landscape of solar energy conversion as well as materials processing and characterization Based on the new and fundamental research on novel energy materials with tailor-made photonic properties, the role of materials engineering has been to provide much needed support in the development of photovoltaic devices. Advanced Energy Materials offers a unique, state-of-the-art look at the new world of novel energy materials science, shedding light on the subject's vast multi-disciplinary approach The book focuses p

  10. Materials by design

    International Nuclear Information System (INIS)

    Major developments in materials characterization instrumentation over the past decade have helped significantly to elucidate complex processes and phenomena connected with the microstructure of materials and interfacial interactions. Equally remarkable advances in theoretical models and computer technology also have been taking place during this period. These latter now permit, for example, in selected cases the computation of material structures and bonding and the prediction of some material properties. Two assessments of the state of the art of instrumental techniques and theoretical methods for the study of material structures and properties have recently been conducted. This paper discusses aspects from these assessments of computational theoretical methods apply to materials

  11. Materials Test Branch

    Science.gov (United States)

    Gordon, Gail

    2012-01-01

    The Materials Test Branch resides at Marshall Space Flight Center's Materials and Processing laboratory and has a long history of supporting NASA programs from Mercury to the recently retired Space Shuttle. The Materials Test Branch supports its customers by supplying materials testing expertise in a wide range of applications. The Materials Test Branch is divided into three Teams, The Chemistry Team, The Tribology Team and the Mechanical Test Team. Our mission and goal is to provide world-class engineering excellence in materials testing with a special emphasis on customer service.

  12. [Elastomeric impression materials].

    Science.gov (United States)

    Anagnostopoulos, T; Tsokas, K

    1990-01-01

    A review of the literature on elastomeric impression materials, is presented in this paper. The article mentions the composition and the most important properties of the elastomeric impression materials used in dental practice. The clinical significance of these materials, physical and mechanical properties are also emphasized. In addition some new elastomeric impression materials with improved properties and a new (experimental) light-cured impression material, are mentioned. Another part of this article is the biocompatibility of these materials. In the end the great significance of handling is outlined. PMID:2130039

  13. Materials Discovery: Informatic Strategies for Optical Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, Kim F.; Webb-Robertson, Bobbie-Jo M.; Jones, Dumont M.

    2007-01-15

    Information-based materials discovery offers a structured method to evolve materials signatures based upon their physical properties, and to direct searches using performance-based criteria. In this current paper, we focus on the crystal structure aspects of an optical material and construct an information-based model to determine the proclivity of a particular AB composition to exhibit multiple crystal system behavior. Exploratory data methods used both supervised (support-vector machines) and unsupervised (disorder-reduction and principal-component) classification methods for structural signature development; revealing complementary valid signatures. Examination of the relative contributions of the materials chemistry descriptors within these signatures indicates a strong role for Mendeleev number chemistry which must be balanced against the cationic/anionic radius ratio and electronegativity differences of constituents within the unit cell.

  14. EC Transmission Line Materials

    International Nuclear Information System (INIS)

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH and CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. (Ref. 2) Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  15. EC Transmission Line Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, Tim S [ORNL

    2012-05-01

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH&CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. [Ref. 2] Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  16. Practical materials characterization

    CERN Document Server

    2014-01-01

    Presents cross-comparison between materials characterization techniquesIncludes clear specifications of strengths and limitations of each technique for specific materials characterization problemFocuses on applications and clear data interpretation without extensive mathematics

  17. Silicone azide fireproof material

    Science.gov (United States)

    1978-01-01

    Finely powdered titanium oxide was added to silicone azide as the sintering agent to produce a nonflammable material. Mixing proportions, physical properties, and chemical composition of the fireproofing material are included.

  18. Advanced functional materials

    CERN Document Server

    2011-01-01

    This book reviews the results of recent research on new materials arising from progress in polymer, ceramic, sensor, and fuel cell technology, including advanced inorganic-organic-hybrid polymeric materials, high functional sensor, and microbial fuel cells.

  19. Nanostructured composite reinforced material

    Science.gov (United States)

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  20. Renewable smart materials

    Science.gov (United States)

    Kim, Hyun Chan; Mun, Seongcheol; Ko, Hyun-U.; Zhai, Lindong; Kafy, Abdullahil; Kim, Jaehwan

    2016-07-01

    The use of renewable materials is essential in future technologies to harmonize with our living environment. Renewable materials can maintain our resources from the environment so as to overcome degradation of natural environmental services and diminished productivity. This paper reviews recent advancement of renewable materials for smart material applications, including wood, cellulose, chitin, lignin, and their sensors, actuators and energy storage applications. To further improve functionality of renewable materials, hybrid composites of inorganic functional materials are introduced by incorporating carbon nanotubes, titanium dioxide and tin oxide conducting polymers and ionic liquids. Since renewable materials have many advantages of biocompatible, sustainable, biodegradable, high mechanical strength and versatile modification behaviors, more research efforts need to be focused on the development of renewable smart materials.

  1. Modern electronic materials

    CERN Document Server

    Watkins, John B

    2013-01-01

    Modern Electronic Materials focuses on the development of electronic components. The book first discusses the history of electronic components, including early developments up to 1900, developments up to World War II, post-war developments, and a comparison of present microelectric techniques. The text takes a look at resistive materials. Topics include resistor requirements, basic properties, evaporated film resistors, thick film resistors, and special resistors. The text examines dielectric materials. Considerations include basic properties, evaporated dielectric materials, ceramic dielectri

  2. Machinability of advanced materials

    CERN Document Server

    Davim, J Paulo

    2014-01-01

    Machinability of Advanced Materials addresses the level of difficulty involved in machining a material, or multiple materials, with the appropriate tooling and cutting parameters.  A variety of factors determine a material's machinability, including tool life rate, cutting forces and power consumption, surface integrity, limiting rate of metal removal, and chip shape. These topics, among others, and multiple examples comprise this research resource for engineering students, academics, and practitioners.

  3. Electronics materials research

    Science.gov (United States)

    1982-01-01

    The electronic materials and is aimed at the establishment of quantitative relationships underlying crystal growth parameters, materials properties, electronic characteristics and device applications. The overall program evolves about the following main thrust areas: (1) crystal growth novel approaches to engineering of semiconductor materials; (2) investigation of materials properties and electronic characteristics on a macro and microscale; (3) surface properties and surface interactions with the bulk and ambients; (4) electronic properties controlling device applications and device performance.

  4. Analysis of irradiated materials

    International Nuclear Information System (INIS)

    Papers presented at the UKAEA Conference on Materials Analysis by Physical Techniques (1987) covered a wide range of techniques as applied to the analysis of irradiated materials. These varied from reactor component materials, materials associated with the Authority's radwaste disposal programme, fission products and products associated with the decommissioning of nuclear reactors. An invited paper giving a very comprehensive review of Laser Ablation Microprobe Mass Spectroscopy (LAMMS) was included in the programme. (author)

  5. Fusion reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  6. Raw material versus processing

    International Nuclear Information System (INIS)

    Some brazilian aspects related with the obtainment of raw materials for advanced ceramic products are described. The necessity of import raw materials by the advanced ceramic industries is mentioned, generating dangerous depedence for the country. The brazilian mineral reserves for using in raw materials of advanced ceramic are also cited. (C.G.C.)

  7. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    The overall objective of this collection is to provide the most recent developments within the various areas of conducting polymeric materials. The conductivity of polymeric materials is caused by electrically charged particles, ions, protons and electrons. Materials in which electrons are the ch...... awarded the Nobel Prize in chemistry “for the discovery and development of conductive polymers”....

  8. Fusion reactor materials

    International Nuclear Information System (INIS)

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics

  9. Computing and Material

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin

    2013-01-01

    The digital is often said to bring us away from material. The adverse is true: digital design and fabrication grants new interfaces towards material and allows architectural design to engage with material on architectural scale in a way that is further reaching than ever before....

  10. Magnetism Materials and Applications

    CERN Document Server

    Trémolet de Lacheisserie, Étienne; Schlenker, Michel

    2005-01-01

    This book treats permanent magnet (hard) materials, magnetically soft materials for low-frequency applications and for high-frequency electronics, magnetostrictive materials, superconductors, magnetic-thin films and multilayers, and ferrofluids. Chapters are dedicated to magnetic recording, the role of magnetism in magnetic resonance imaging (MRI), and instrumentation for magnetic measurements.   

  11. Meanings of Materials

    NARCIS (Netherlands)

    Karana, E.

    2009-01-01

    This book is about meanings we attribute to materials of the objects around us. Materials convey meanings: they look traditional, they express luxury, they are associated with factories, or they conjure up one’s childhood. How do materials obtain these meanings? How do they interact with other e

  12. Safer Aviation Materials Tested

    Science.gov (United States)

    Palaszewski, Bryan A.

    2001-01-01

    A series of thermally stable polymer samples were tested. These materials are called low heat release materials and are designed for aircraft interior decorative materials. The materials are designed to give off a minimum amount of noxious gases when heated, which increases the possibility that people can escape from a burning aircraft. New cabin materials have suitably low heat release so that fire does not spread, toxic chemicals are not given off, and the fire-emergency escape time for crew and passengers is lengthened. These low heat-release materials have a variety of advantages and applications: interiors for ground-based facilities, interiors of space vehicles, and many commercial fire-protection environments. A microscale combustion calorimeter at the Federal Aviation Administration's (FAA) Technical Center tested NASA Langley Research Center materials samples. The calorimeter is shown. A sharp, quantitative, and reproducible heat-release-rate peak is obtained in the microscale heat-release-rate test. The newly tested NASA materials significantly reduced the heat release capacity and total heat release. The thermal stability and flammability behavior of the samples was very good. The new materials demonstrated a factor of 4 reduction in total heat release over ULTEM (a currently used material). This information is provided in the following barchart. In other tests, the materials showed greater than a factor 9 reduction in heat-release capacity over ULTEM. The newly tested materials were developed for low dielectric constant, low color, and good solubility. A scale up of the material samples is needed to determine the repeatability of the performance in larger samples. Larger panels composed of the best candidate materials will be tested in a larger scale FAA Technical Center fire facility. The NASA Glenn Research Center, Langley (Jeff Hinkley), and the FAA Technical Center (Richard Lyon) cooperatively tested these materials for the Accident Mitigation

  13. Tailored Porous Materials

    Energy Technology Data Exchange (ETDEWEB)

    BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

    1999-11-09

    Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

  14. Advances in dental materials.

    Science.gov (United States)

    Vaderhobli, Ram M

    2011-07-01

    The use of materials to rehabilitate tooth structures is constantly changing. Over the past decade, newer material processing techniques and technologies have significantly improved the dependability and predictability of dental material for clinicians. The greatest obstacle, however, is in choosing the right combination for continued success. Finding predictable approaches for successful restorative procedures has been the goal of clinical and material scientists. This article provides a broad perspective on the advances made in various classes of dental restorative materials in terms of their functionality with respect to pit and fissure sealants, glass ionomers, and dental composites. PMID:21726695

  15. New materials in defence

    International Nuclear Information System (INIS)

    National defence is very important and always needs new such materials which have technological and socio-economic development of human society. The types of materials used by a society reflect its level of sophistication. These modern materials are basically the same conventional materials but with a greater knowledge content which include superalloys, modern polymers, engineering ceramics and the advanced composite. The production and use of new materials is playing and important role in the recent development in the defence industry. (A.B.)

  16. Terminology of carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, G.N.; Nagornyi, V.G.; Ostrovskii, V.S.

    1986-07-01

    The need is discussed to standardize definition of carbonaceous material. Terms related to carbonaceous materials and their products are selected and analyzed. Diagramatic representation is given of relationships between carbonaceous materials. Carbon has two forms of structure, cubic and hexagonal, characterized by sp/sup 3/-hybrid groups of atoms forming spatial system of tetrahedral bonds. Hexagonal form of carbon is represented by natural materials such as graphite, shungite, anthracite and a number of artificial materials obtained during thermal treatment of organic substances at temperatures above carbonization temperature. 4 references.

  17. Advances in electronic materials

    CERN Document Server

    Kasper, Erich; Grimmeiss, Hermann G

    2008-01-01

    This special-topic volume, Advances in Electronic Materials, covers various fields of materials research such as silicon, silicon-germanium hetero-structures, high-k materials, III-V semiconductor alloys and organic materials, as well as nano-structures for spintronics and photovoltaics. It begins with a brief summary of the formative years of microelectronics; now the keystone of information technology. The latter remains one of the most important global technologies, and is an extremely complex subject-area. Although electronic materials are primarily associated with computers, the internet

  18. Advanced materials-2007

    International Nuclear Information System (INIS)

    The 10th International Symposium on Advanced Materials (ISAM) was held from 3-7 September, 2007. From this symposium, material scientists and engineers can keep abreast with recent technologies involving advanced structural and functional materials. The proceeding of ISAM includes 94 papers which have been divided into six different sections: i) Development in material processing ii) Surface Engineering iii) phase transformation iv) advances in magnetic materials v) Nanotechnology and vi) reliability and life assessment. ISAM provides the opportunity to exchange technical know-how amongst Scientists, Engineers and researchers. (A.B.)

  19. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed

  20. ON - SITE MATERIAL MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Sahil.R.Choure

    2015-06-01

    Full Text Available Site material management is a process for controlling field and office activities on construction site related to the materials. The site material management system attempts to insure that the right quality and quantity of materials are appropriately delivered and handled onsite in a timely manner. Planning a nd controlling all of the efforts necessary to ensure that the correct quality and quantity of materials are properly specified in a timely manner and most importantly are available at the point of use when required. Materials management is the system whic h represents a major expense in construction, so improving site material management improves opportunities for reducing the overall project costs. Poor management can result in increased costs during construction. Efficient management of materials can resu lt in substantial savings in project costs. This project is about on - site material control and the aim is to minimize delays, wastage of material and indirectly the cost. The project’s focus is on material quality control, proper storage facility, materia l accounting on site of Amanora future towers. The project concentrated on the products that contribute the most to construction organization revenue. Study will be done to understand and analyze the above practices on the construction project of Amanora f uture towers.

  1. Contact materials for nanoelectronics

    KAUST Repository

    Alshareef, Husam N.

    2011-02-01

    In this article, we review current research activities in contact material development for electronic and nanoelectronic devices. A fundamental issue in contact materials research is to understand and control interfacial reactions and phenomena that modify the expected device performance. These reactions have become more challenging and more difficult to control as new materials have been introduced and as device sizes have entered the deep nanoscale. To provide an overview of this field of inquiry, this issue of MRS Bulletin includes articles on gate and contact materials for Si-based devices, junction contact materials for Si-based devices, and contact materials for alternate channel substrates (Ge and III-V), nanodevices. © 2011 Materials Research Society.

  2. Comprehensive nuclear materials

    CERN Document Server

    Allen, Todd; Stoller, Roger; Yamanaka, Shinsuke

    2012-01-01

    Comprehensive Nuclear Materials encapsulates a panorama of fundamental information on the vast variety of materials employed in the broad field of nuclear technology. The work addresses, in five volumes, 3,400 pages and over 120 chapter-length articles, the full panorama of historical and contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds' leading scientists and engineers. It synthesizes the most pertinent research to support the selection, assessment, validation and engineering of materials in extreme nuclear environments. The work discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials.

  3. Multicomponent polymeric materials

    CERN Document Server

    Thomas, Sabu; Saha, Prosenjit

    2016-01-01

    The book offers an in-depth review of the materials design and manufacturing processes employed in the development of multi-component or multiphase polymer material systems. This field has seen rapid growth in both academic and industrial research, as multiphase materials are increasingly replacing traditional single-component materials in commercial applications. Many obstacles can be overcome by processing and using multiphase materials in automobile, construction, aerospace, food processing, and other chemical industry applications. The comprehensive description of the processing, characterization, and application of multiphase materials presented in this book offers a world of new ideas and potential technological advantages for academics, researchers, students, and industrial manufacturers from diverse fields including rubber engineering, polymer chemistry, materials processing and chemical science. From the commercial point of view it will be of great value to those involved in processing, optimizing an...

  4. Dealloying and Dealloyed Materials

    Science.gov (United States)

    McCue, Ian; Benn, Ellen; Gaskey, Bernard; Erlebacher, Jonah

    2016-07-01

    A successful working model for nanoporosity evolution during dealloying was introduced 15 years ago. Since that time, the field has rapidly expanded, with research groups from across the world studying dealloying and dealloyed materials. Dealloying has grown into a rich field, with some groups focusing on fundamentals and mechanisms of dealloying, other groups creating new porous metals and alloys, and even more groups studying their properties. Dealloying was originally considered only in the context of corrosion, but now it is considered a facile self-organization technique to fabricate high-surface-area, bicontinuous nanoporous materials. Owing to their high interfacial area and the versatility of metallic materials, nanoporous metals have found application in catalysis, sensing, actuation, electrolytic and ultracapacitor materials, high-temperature templates/scaffolds, battery anodes, and radiation damage–tolerant materials. In this review, we discuss the fundamental materials principles underlying the formation of dealloyed materials and then look at two major applications: catalysis and nanomechanics.

  5. Articulating Material Criteria

    DEFF Research Database (Denmark)

    Hasling, Karen Marie

    2013-01-01

    , imitate and articulate the students’ inclusion of materials. This paper particularly discusses the experiences made and ideas generated after the execution of a material science course for second year students, with emphasis on the concept of the material selection matrix as an educational tool for......This paper discusses the experiences and potentials with materials teaching at the Institute for Product Design at Kolding School of Design, using materials teaching as experiments in my PhD project. The project intents to create a stronger material awareness among product design students with...... emphasis on sustainability. The experiments aim to develop an understanding of, how product design students include materials in their design practice and how tools can be developed that further enhance this. Hence experiments are essential for the progress of the PhD project as they help to observe...

  6. Comprehensive hard materials

    CERN Document Server

    2014-01-01

    Comprehensive Hard Materials deals with the production, uses and properties of the carbides, nitrides and borides of these metals and those of titanium, as well as tools of ceramics, the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials), milling, granulation, cold and hot compaction, sintering, hot isostatic pressing, hot-pressing, injection moulding, as well as on the coating technologies for refractory metals, hard metals and hard materials. The characterization, testing, quality assurance and applications are also covered. Comprehensive Hard Materials provides meaningful insights on materials at the leading edge of technology. It aids continued research and development of these materials and as such it is a critical information resource to academics and industry professionals facing the technological challenges of the future. Hard materials operate at the leading edge of technology, and continued res...

  7. Modelling of thermoelectric materials

    DEFF Research Database (Denmark)

    Bjerg, Lasse

    In order to discover new good thermoelectric materials, there are essentially two ways. One way is to go to the laboratory, synthesise a new material, and measure the thermoelectric properties. The amount of compounds, which can be investigated this way is limited because the process is time...... consuming. Another approach is to model the thermoelectric properties of a material on a computer. Several crystal structures can be investigated this way without use of much man power. I have chosen the latter approach. Using density functional theory I am able to calculate the band structure of a material....... This band structure I can then use to calculate the thermoelectric properties of the material. With these results I have investigated several materials and found the optimum theoretical doping concentration. If materials with these doping concentrations be synthesised, considerably better thermoelectric...

  8. Materials research for fusion

    Science.gov (United States)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  9. Heterogeneous Materials I and Heterogeneous Materials II

    International Nuclear Information System (INIS)

    In these two volumes the author provides a comprehensive survey of the various mathematically-based models used in the research literature to predict the mechanical, thermal and electrical properties of hetereogeneous materials, i.e., materials containing two or more phases such as fibre-reinforced polymers, cast iron and porous ceramic kiln furniture. Volume I covers linear properties such as linear dielectric constant, effective electrical conductivity and elastic moduli, while Volume II covers nonlinear properties, fracture and atomistic and multiscale modelling. Where appropriate, particular attention is paid to the use of fractal geometry and percolation theory in describing the structure and properties of these materials. The books are advanced level texts reflecting the research interests of the author which will be of significant interest to research scientists working at the forefront of the areas covered by the books. Others working more generally in the field of materials science interested in comparing predictions of properties with experimental results may well find the mathematical level quite daunting initially, as it is apparent that the author assumes a level of mathematics consistent with that taught in final year undergraduate and graduate theoretical physics courses. However, for such readers it is well worth persevering because of the in-depth coverage to which the various models are subjected, and also because of the extensive reference lists at the back of both volumes which direct readers to the various source references in the scientific literature. Thus, for the wider materials science scientific community the two volumes will be a valuable library resource. While I would have liked to see more comparison with experimental data on both ideal and 'real' heterogeneous materials than is provided by the author and a discussion of how to model strong nonlinear current--voltage behaviour in systems such as zinc oxide varistors, my overall

  10. Fusion reactor materials

    International Nuclear Information System (INIS)

    This is the fifteenth in a series of semiannual technical progress reports on fusion reactor materials. This report combines research and development activities which were previously reported separately in the following progress reports: Alloy Development for Irradiation Performance; Damage Analysis and Fundamental Studies; Special purpose Materials. These activities are concerned principally with the effects of the neutronic and chemical environment on the properties and performance of reactor materials; together they form one element of the overall materials programs being conducted in support of the Magnetic Fusion Energy Program of the U.S. Department of Energy. The Fusion Reactor Materials Program is a national effort involving several national laboratories, universities, and industries. The purpose of this series of reports is to provide a working technical record for the use of the program participants, and to provide a means of communicating the efforts of materials scientists to the rest of the fusion community, both nationally and worldwide

  11. Hydrophilic nanoporous materials

    DEFF Research Database (Denmark)

    2010-01-01

    The present application discloses a method for preparing and rendering hydrophilic a nanoporous material of a polymer matrix which has a porosity of 0.1-90 percent (v/v), such that the ratio between the final water absorption (percent (w/w)) and the porosity (percent (v/v)) is at least 0.05, the...... method comprising the steps of: (a) preparing a precursor material comprising at least one polymeric component and having a first phase and a second phase; (b) removal of at least a part of the first phase of the precursor material prepared in step (a) so as to leave behind a nanoporous material of the...... polymer matrix; (c) irradiating at least a part of said nanoporous material with light of a wave length of in the range of 250-400 nm (or 200-700 nm) in the presence of oxygen and/or ozone. Corresponding hydrophilic nanoporous materials are also disclosed. L...

  12. Auditing nuclear materials statements

    International Nuclear Information System (INIS)

    A standard that may be used as a guide for persons making independent examinations of nuclear materials statements or reports regarding inventory quantities on hand, receipts, production, shipment, losses, etc. is presented. The objective of the examination of nuclear materials statements by the independent auditor is the expression of an opinion on the fairness with which the statements present the nuclear materials position of a nuclear materials facility and the movement of such inventory materials for the period under review. The opinion is based upon an examination made in accordance with auditing criteria, including an evaluation of internal control, a test of recorded transactions, and a review of measured discards and materials unaccounted for (MUF). The standard draws heavily upon financial auditing standards and procedures published by the American Institute of Certified Public Accountants

  13. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    A short overview of micromechanical models of hierarchical materials (hybrid composites, biomaterials, fractal materials, etc.) is given. Several examples of the modeling of strength and damage in hierarchical materials are summarized, among them, 3D FE model of hybrid composites with...... nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them, the...... investigations of the effects of load redistribution between reinforcing elements at different scale levels, of the possibilities to control different material properties and to ensure synergy of strengthening effects at different scale levels and using the nanoreinforcement effects. The main future directions...

  14. Basic Electromagnetism and Materials

    CERN Document Server

    Moliton, André

    2007-01-01

    Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

  15. Reinforcement of ceramic materials

    International Nuclear Information System (INIS)

    In the commercial field, greater reproduceability of ceramic materials was achieved by systematic process control of the steps in manufacture. By improvement of the microstructure design, the strength and toughness against tearing of the materials were increased. The articles give a survey of theoretical and experimental results in manufacture and of the composition of ceramics with reinforced structure. Preferred materials are zirconium-, aluminium- and yttrium oxide, silicon oxide and -nitride and titanium- and silicon carbide. (DG)

  16. Strongly Correlated Materials

    OpenAIRE

    Morosan, Emilia; Natelson, Douglas; Nevidomskyy, Andriy H.; Si, Qimiao

    2013-01-01

    Strongly correlated materials are profoundly affected by the repulsive electron-electron interaction. This stands in contrast to many commonly used materials such as silicon and aluminum, whose properties are comparatively unaffected by the Coulomb repulsion. Correlated materials often have remarkable properties and transitions between distinct, competing phases with dramatically different electronic and magnetic orders. These rich phenomena are fascinating from the basic science perspective ...

  17. ANS materials databook

    Energy Technology Data Exchange (ETDEWEB)

    Marchbanks, M.F.

    1995-08-01

    Technical development in the Advanced Neutron Source (ANS) project is dynamic, and a continuously updated information source is necessary to provide readily usable materials data to the designer, analyst, and materials engineer. The Advanced Neutron Source Materials Databook (AMBK) is being developed as a part of the Advanced Neutron Source Materials Information System (AMIS). Its purpose is to provide urgently needed data on a quick-turnaround support basis for those design applications whose schedules demand immediate estimates of material properties. In addition to the need for quick materials information, there is a need for consistent application of data throughout the ANS Program, especially where only limited data exist. The AMBK is being developed to fill this need as well. It is the forerunner to the Advanced Neutron Source Materials Handbook (AMHB). The AMHB, as reviewed and approved by the ANS review process, will serve as a common authoritative source of materials data in support of the ANS Project. It will furnish documented evidence of the materials data used in the design and construction of the ANS system and will serve as a quality record during any review process whose objective is to establish the safety level of the ANS complex. The information in the AMBK and AMHB is also provided in electronic form in a dial-up computer database known as the ANS Materials Database (AMDB). A single consensus source of materials information prepared and used by all national program participants has several advantages. Overlapping requirements and data needs of various sub-projects and subcontractors can be met by a single document which is continuously revised. Preliminary and final safety analysis reports, stress analysis reports, equipment specifications, materials service reports, and many other project-related documents can be substantially reduced in size and scope by appropriate reference to a single data source.

  18. Materials Made to Last

    International Nuclear Information System (INIS)

    High temperatures, irradiation, mechanical stresses, corrosive environments, etc. The materials used in nuclear power plants are subjected to extreme conditions. Guaranteeing the safety, lifespan and performance levels of current reactors, while designing and qualifying new materials capable of resisting the specific constraints of future nuclear systems, are the main issues investigated at the CEA-DEN in the field of nuclear materials. To meet these requirements, researchers at the CEA have access to a wealth of feedback, skills and unparalleled experimental facilities. (authors)

  19. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  20. Joining of advanced materials

    CERN Document Server

    Messler, Robert W

    1993-01-01

    Provides an unusually complete and readable compilation of the primary and secondary options for joining conventional materials in non-conventional ways. Provides unique coverage of adhesive bonding using both organic and inorganic adhesives, cements and mortars. Focuses on materials issues without ignoring issues related to joint design, production processing, quality assurance, process economics, and joining performance in service.Joining of advanced materials is a unique treatment of joining of both conventional and advanced metals andalloys, intermetallics, ceramics, glasses, polymers, a

  1. ANS materials databook

    International Nuclear Information System (INIS)

    Technical development in the Advanced Neutron Source (ANS) project is dynamic, and a continuously updated information source is necessary to provide readily usable materials data to the designer, analyst, and materials engineer. The Advanced Neutron Source Materials Databook (AMBK) is being developed as a part of the Advanced Neutron Source Materials Information System (AMIS). Its purpose is to provide urgently needed data on a quick-turnaround support basis for those design applications whose schedules demand immediate estimates of material properties. In addition to the need for quick materials information, there is a need for consistent application of data throughout the ANS Program, especially where only limited data exist. The AMBK is being developed to fill this need as well. It is the forerunner to the Advanced Neutron Source Materials Handbook (AMHB). The AMHB, as reviewed and approved by the ANS review process, will serve as a common authoritative source of materials data in support of the ANS Project. It will furnish documented evidence of the materials data used in the design and construction of the ANS system and will serve as a quality record during any review process whose objective is to establish the safety level of the ANS complex. The information in the AMBK and AMHB is also provided in electronic form in a dial-up computer database known as the ANS Materials Database (AMDB). A single consensus source of materials information prepared and used by all national program participants has several advantages. Overlapping requirements and data needs of various sub-projects and subcontractors can be met by a single document which is continuously revised. Preliminary and final safety analysis reports, stress analysis reports, equipment specifications, materials service reports, and many other project-related documents can be substantially reduced in size and scope by appropriate reference to a single data source

  2. Asian material culture

    OpenAIRE

    2009-01-01

    This exciting, richly illustrated volume gives the reader a unique insight into the materiality of Asian cultures and the ways in which objects and practices can simultaneously embody and exhibit aesthetic and functional characteristics, everyday and spiritual aspirations. Material culture is examined from a variety of perspectives and the authors rigorously investigate the creation and meaning of material object, and their associated practices within the context of time and place. All chapte...

  3. Femtosecond laser materials processing

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B. C., LLNL

    1998-06-02

    Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area Applications ranging from drilling teeth to cutting explosives to making high-aspect ratio cuts in metals with no heat-affected zone are made possible by this technology For material removal at reasonable rates, we developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.

  4. Femtosecond laser materials processing

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B

    1998-08-05

    Femtosecond lasers enable materials processing of most any material with extremely high precision and negligible shock or thermal loading to the surrounding area. Applications ranging from drilling teeth to cutting explosives to precision cuts in composites are possible by using this technology. For material removal at reasonable rates, we have developed a fully computer-controlled 15-Watt average power, 100-fs laser machining system.

  5. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  6. Optimized manufacturable porous materials

    OpenAIRE

    Andreassen, Erik; Andreasen, Casper Schousboe; Jensen, Jakob Søndergaard; Sigmund, Ole

    2012-01-01

    Topology optimization has been used to design two-dimensional material structures with specific elastic properties, but optimized designs of three-dimensional material structures are more scarsely seen. Partly because it requires more computational power, and partly because it is a major challenge to include manufacturing constraints in the optimization.This work focuses on incorporating the manufacturability into the optimization procedure, allowing the resulting material structure to be man...

  7. Combinatorial materials synthesis

    OpenAIRE

    Ichiro Takeuchi; Jochen Lauterbach; Michael J. Fasolka

    2005-01-01

    The pace at which major technological changes take place is often dictated by the rate at which new materials are discovered, and the timely arrival of new materials has always played a key role in bringing advances to our society. It is no wonder then that the so-called combinatorial or high-throughput strategy has been embraced by practitioners of materials science in virtually every field. High-throughput experimentation allows simultaneous synthesis and screening of large arrays of differ...

  8. Frontiers in Superconducting Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Superconducting Materials gives a state-of-the-art report of the most important topics of the current research in superconductive materials and related phenomena. It comprises 30 chapters written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students. It also addresses electronic and electrical engineers. Even non-specialists interested in superconductivity might find some useful answers.

  9. Materials Behavior Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to evaluate mechanical properties of materials including metals, intermetallics, metal-matrix composites, and ceramic-matrix composites under typical...

  10. Materials development for TESOL

    CERN Document Server

    Mishan, Freda

    2015-01-01

    Materials development has become much more important in the field of TESOL in the last twenty years: modules on materials development are now commonplace on MA TESOL courses around the world. The overall aim of the book is to introduce readers to a wide range of theoretical and practical issues in materials development to enable them to make informed and principled choices in the selection, evaluation, adaptation and production of materials. The book aims to show how these choices need to be informed by an awareness of culture, context and purpose.

  11. Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Materials Characterization Facility enables detailed measurements of the properties of ceramics, polymers, glasses, and composites. It features instrumentation...

  12. Functional Hybrid Materials

    Science.gov (United States)

    Gómez-Romero, Pedro; Sanchez, Clément

    2004-04-01

    Functional Hybrid Materials consist of both organic and inorganic components, assembled for the purpose of generating desirable properties and functionalities. The aim is twofold: to bring out or enhance advantageous chemical, electrochemical, magnetic or electronic characteristics and at the same time to reduce or wholly suppress undesirable properties or effects. Another target is the creation of entirely new material behavior. The vast number of hybrid material components available has opened up a wide and diversified field of fascinating research. In this book, a team of highly renowned experts gives an in-depth overview, illustrating the superiority of well-designed hybrid materials and their potential applications.

  13. Materials information data bank

    International Nuclear Information System (INIS)

    A major concern in the design of weapons systems is compatibility of materials with each other and with the enclosed environment. Usually these systems require long-term storage and must have high reliability at the end of this storage period. Materials selection is thus based on past experience and on laboratory-accelerated testing to assure this long-term reliability. To assist in materials selection, a computerized materials data bank has been established. In addition to references on personnel and documents, this data bank provides annotated information on materials so that the designer and materials engineer can draw on it for guidance in selecting materials. The primary purpose of the data bank is to provide materials compatibility data. However, the structure of the system permits the data bank to be used for storage and retrieval of general materials information. The data bank storage and information retrieval philosophy is discussed and procedures for information gathering are outlined. Examples of data entries and a list of search routines are presented to demonstrate the usefulness and versatility of the system

  14. The Materials Genome Project

    Science.gov (United States)

    Aourag, H.

    2008-09-01

    In the past, the search for new and improved materials was characterized mostly by the use of empirical, trial- and-error methods. This picture of materials science has been changing as the knowledge and understanding of fundamental processes governing a material's properties and performance (namely, composition, structure, history, and environment) have increased. In a number of cases, it is now possible to predict a material's properties before it has even been manufactured thus greatly reducing the time spent on testing and development. The objective of modern materials science is to tailor a material (starting with its chemical composition, constituent phases, and microstructure) in order to obtain a desired set of properties suitable for a given application. In the short term, the traditional "empirical" methods for developing new materials will be complemented to a greater degree by theoretical predictions. In some areas, computer simulation is already used by industry to weed out costly or improbable synthesis routes. Can novel materials with optimized properties be designed by computers? Advances in modelling methods at the atomic level coupled with rapid increases in computer capabilities over the last decade have led scientists to answer this question with a resounding "yes'. The ability to design new materials from quantum mechanical principles with computers is currently one of the fastest growing and most exciting areas of theoretical research in the world. The methods allow scientists to evaluate and prescreen new materials "in silico" (in vitro), rather than through time consuming experimentation. The Materials Genome Project is to pursue the theory of large scale modeling as well as powerful methods to construct new materials, with optimized properties. Indeed, it is the intimate synergy between our ability to predict accurately from quantum theory how atoms can be assembled to form new materials and our capacity to synthesize novel materials atom

  15. Frontiers in Magnetic Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Magnetic Materials focuses on the current achievements and state-of-the-art advancements in magnetic materials. Several lines of development- High-Tc Superconductivity, Nanotechnology and refined experimental techniques among them – raised knowledge and interest in magnetic materials remarkably. The book comprises 24 chapters on the most relevant topics written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students.

  16. Multifunctional Composite Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Polymeric composite materials that are currently utilized in aircraft structures are susceptible to significant damage from lightning strikes. Enhanced electrical...

  17. Reactor Materials Research

    International Nuclear Information System (INIS)

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel

  18. Smuggling special nuclear materials

    International Nuclear Information System (INIS)

    Ever since the collapse of the former Soviet Union reports have circulated with increasing frequency concerning attempts to smuggle materials from that country's civil and military nuclear programs. Such an increase obviously raises a number of concerns (outlined in the author's introduction), chief among which is the possibility that these materials might eventually fall into the hands of proliferant states or terrorist groups. The following issues are presented: significance of materials being smuggled; sources and smuggling routes; potential customers; international efforts to reduce nuclear smuggling; long-term disposition of fissile materials. (author)

  19. Material for radioactive protection

    Science.gov (United States)

    Taylor, R.S.; Boyer, N.W.

    A boron containing burn resistant, low-level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source is described. The material is basically composed of borax in the range of 25 to 50%, coal tar in the range of 25 to 37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  20. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the behaviour of fusion reactor materials and components during and after irradiation. Ongoing projects include: the study of the mechanical behaviour of structural materials under neutron irradiation; the investigation of the characteristics of irradiated first wall material such as beryllium; the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; and the study of dismantling and waste disposal strategy for fusion reactors. Progress and achievements in these areas in 2000 are discussed

  1. Superconducting composites materials

    International Nuclear Information System (INIS)

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa2Cu3O7-δ material. We first realized a composite material glass/YBa2Cu3O7-δ, by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa2Cu3O7-δ material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs

  2. Advanced thermal management materials

    CERN Document Server

    Jiang, Guosheng; Kuang, Ken

    2012-01-01

    ""Advanced Thermal Management Materials"" provides a comprehensive and hands-on treatise on the importance of thermal packaging in high performance systems. These systems, ranging from active electronically-scanned radar arrays to web servers, require components that can dissipate heat efficiently. This requires materials capable of dissipating heat and maintaining compatibility with the packaging and dye. Its coverage includes all aspects of thermal management materials, both traditional and non-traditional, with an emphasis on metal based materials. An in-depth discussion of properties and m

  3. Materials for Slack Diaphragms

    Science.gov (United States)

    Puschmann, Traute

    1940-01-01

    This report deals with systematic experiments carried out on five diaphragm materials with different pretreatment, for the purpose of ascertaining the suitability of such materials for slack diaphragms. The relationship of deflection and load, temperature and moisture, was recorded. Of the explored materials, synthetic leather, balloon cloth, goldbeaters skin, Igelit and Buna, synthetic leather treated with castor oil is the most suitable material for the small pressure range required. Balloon cloth is nearly as good, while goldbeaters skin, Igelit and Buna were found to be below the required standards.

  4. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2002-04-01

    The activities of SCK-CEN's Reactor Materials Research Department for 2001 are summarised. The objectives of the department are: (1) to evaluate the integrity and behaviour of structural materials used in nuclear power industry; (2) to conduct research to unravel and understand the parameters that determine the material behaviour under or after irradiation; (3) to contribute to the interpretation, the modelling of the material behaviour and to develop and assess strategies for optimum life management of nuclear power plant components. The programmes within the department are focussed on studies concerning (1) Irradiation Assisted Stress Corrosion Cracking (IASCC); (2) nuclear fuel; and (3) Reactor Pressure Vessel Steel.

  5. Materials information data bank

    Energy Technology Data Exchange (ETDEWEB)

    Mead, K.E.

    1978-03-01

    A major concern in the design of weapons systems is compatibility of materials with each other and with the enclosed environment. Usually these systems require long-term storage and must have high reliability at the end of this storage period. Materials selection is thus based on past experience and on laboratory-accelerated testing to assure this long-term reliability. To assist in materials selection, a computerized materials data bank has been established. In addition to references on personnel and documents, this data bank provides annotated information on materials so that the designer and materials engineer can draw on it for guidance in selecting materials. The primary purpose of the data bank is to provide materials compatibility data. However, the structure of the system permits the data bank to be used for storage and retrieval of general materials information. The data bank storage and information retrieval philosophy is discussed and procedures for information gathering are outlined. Examples of data entries and a list of search routines are presented to demonstrate the usefulness and versatility of the system.

  6. Biogenic Impact on Materials

    Science.gov (United States)

    Stephan, Ina; Askew, Peter; Gorbushina, Anna; Grinda, Manfred; Hertel, Horst; Krumbein, Wolfgang; Müller, Rolf-Joachim; Pantke, Michael; Plarre, Rüdiger (Rudy); Schmitt, Guenter; Schwibbert, Karin

    Materials as constituents of products or components of technical systems rarely exist in isolation and many must cope with exposure in the natural world. This chapter describes methods that simulate how a material is influenced through contact with living systems such as microorganisms and arthropods. Both unwanted and desirable interactions are considered. This biogenic impact on materials is intimately associated with the environment to which the material is exposed (Materials-Environment Interaction, Chap. 15). Factors such as moisture, temperature and availability of food sources all have a significant influence on biological systems. Corrosion (Chap. 12) and wear (Chap. 13) can also be induced or enhanced in the presence of microorganisms. Section 14.1 introduces the categories between desired (biodegradation) and undesired (biodeterioration) biological effects on materials. It also introduces the role of biocides for the protection of materials. Section 14.2 describes the testing of wood as a building material especially against microorganisms and insects. Section 14.3 characterizes the test methodologies for two other groups of organic materials, namely polymers (Sect. 14.3.1) and paper and textiles (Sect. 14.3.2). Section 14.4 deals with the susceptibility of inorganic materials such as metals (Sect. 14.4.1), concrete (Sect. 14.4.2) and ceramics (Sect. 14.4.3) to biogenic impact. Section 14.5 treats the testing methodology concerned with the performance of coatings and coating materials. In many of these tests specific strains of organisms are employed. It is vital that these strains retain their ability to utilize/attack the substrate from which they were isolated, even when kept for many years in the laboratory. Section 14.6 therefore considers the importance of maintaining robust and representative test organisms that are as capable of utilizing a substrate as their counterparts in nature such that realistic predictions of performance can be made.

  7. Gravitation in Material Media

    Science.gov (United States)

    Ridgely, Charles T.

    2011-01-01

    When two gravitating bodies reside in a material medium, Newton's law of universal gravitation must be modified to account for the presence of the medium. A modified expression of Newton's law is known in the literature, but lacks a clear connection with existing gravitational theory. Newton's law in the presence of a homogeneous material medium…

  8. The Materiality of Research

    DEFF Research Database (Denmark)

    Meier, Ninna

    2016-01-01

    In this feature essay, Ninna Meier reflects on the materiality of the writing – and re-writing – process in academic research. She explores the ways in which our ever-accummulating thoughts come to form layers on the material objects in which we write our notes and discusses the pleasures of co-authorship....

  9. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...... are mentioned. References to review papers, papers with experimental data, and papers describing the thermodynamic modelling of the systems are given....

  10. Materials modified by irradiation

    International Nuclear Information System (INIS)

    Application of radiation in pharmaceutical sciences and cosmetology, polymer materials, food industry, environment, health camre products and packing production is described. Nanotechnology is described more detailed, because it is less known as irradiation using technology. Economic influence of the irradiation on the materials value addition is shown

  11. Impacted material placement plans

    International Nuclear Information System (INIS)

    Impacted material placement plans (IMPP) are documents identifying the essential elements in placing remediation wastes into disposal facilities. Remediation wastes or impacted material(s) are those components used in the construction of the disposal facility exclusive of the liners and caps. The components might include soils, concrete, rubble, debris, and other regulatory approved materials. The IMPP provides the details necessary for interested parties to understand the management and construction practices at the disposal facility. The IMPP should identify the regulatory requirements from applicable DOE Orders, the ROD(s) (where a part of a CERCLA remedy), closure plans, or any other relevant agreements or regulations. Also, how the impacted material will be tracked should be described. Finally, detailed descriptions of what will be placed and how it will be placed should be included. The placement of impacted material into approved on-site disposal facilities (OSDF) is an integral part of gaining regulatory approval. To obtain this approval, a detailed plan (Impacted Material Placement Plan [IMPP]) was developed for the Fernald OSDF. The IMPP provides detailed information for the DOE, site generators, the stakeholders, regulatory community, and the construction subcontractor placing various types of impacted material within the disposal facility

  12. A Material Focus

    DEFF Research Database (Denmark)

    Vallgårda, Anna K. A.; Sokoler, Tomas

    2009-01-01

    In this paper we build on the notion of computational composites, which hold a material perspective on computational technology. We argue that a focus on the material aspects of the technology could be a fruitful approach to achieve new expressions and to gain a new view on the technology's role in...

  13. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  14. The Computational Materials Repository

    DEFF Research Database (Denmark)

    Landis, David D.; Hummelshøj, Jens S.; Nestorov, Svetlozar;

    2012-01-01

    The possibilities for designing new materials based on quantum physics calculations are rapidly growing, but these design efforts lead to a significant increase in the amount of computational data created. The Computational Materials Repository (CMR) addresses this data challenge and provides a...

  15. Radioactivity in building materials

    International Nuclear Information System (INIS)

    The present report, drawn up at the request of the former Minister of Public Health and Environmental Affairs of the Netherlands, discusses the potential radiological consequences for the population of the Netherlands of using waste materials as building materials in housing construction. (Auth.)

  16. Environmental materials and interfaces

    International Nuclear Information System (INIS)

    A workshop that explored materials and interfaces research needs relevant to national environmental concerns was conducted at Pacific Northwest Laboratory. The purposes of the workshop were to refine the scientific research directions being planned for the Materials and Interface Program in the Molecular Science Research Center (MSRC) and further define the research and user equipment to the included as part of the proposed Environmental and Molecular Science Laboratory (EMSL). Three plenary information sessions served to outline the background, objectives, and status of the MSRC and EMSL initiatives; selected specific areas with environmentally related materials; and the status of capabilities and facilities planned for the EMSL. Attention was directed to four areas where materials and interface science can have a significant impact on prevention and remediation of environmental problems: in situ detection and characterization of hazardous wastes (sensors), minimization of hazardous waste (separation membranes, ion exchange materials, catalysts), waste containment (encapsulation and barrier materials), and fundamental understanding of contaminant transport mechanisms. During all other sessions, the participants were divided into three working groups for detailed discussion and the preparation of a written report. The working groups focused on the areas of interface structure and chemistry, materials and interface stability, and materials synthesis. These recommendations and suggestions for needed research will be useful for other researchers in proposing projects and for suggesting collaborative work with MSRC researchers. 1 fig

  17. Scintillator materials for calorimetry

    International Nuclear Information System (INIS)

    Requirements for fast, dense scintillator materials for calorimetry in high energy physics and approaches to satisfying these requirements are reviewed with respect to possible hosts and luminescent species. Special attention is given to cerium-activated crystals, core-valence luminescence, and glass scintillators. The present state of the art, limitations, and suggestions for possible new scintillator materials are presented

  18. Materials modified by irradiation

    International Nuclear Information System (INIS)

    Application of radiation in pharmaceutical sciences and cosmetology, polymer materials, food industry, environment, health camre products and packing production is described. Nano-technology is described more detailed, because it is less known as irradiation using technology. Economic influence of the irradiation on the materials value addition is shown

  19. Transport of Radioactive Materials

    International Nuclear Information System (INIS)

    This address overviews the following aspects: concepts on transport of radioactive materials, quantities used to limit the transport, packages, types of packages, labeling, index transport calculation, tags, labeling, vehicle's requirements and documents required to authorize transportation. These requirements are considered in the regulation of transport of radioactive material that is in drafting step

  20. Material Fatigue Testing System

    Science.gov (United States)

    Gilley, P. J. (Inventor)

    1973-01-01

    A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading.

  1. Micromechanics of hierarchical materials

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon, Jr.

    2012-01-01

    nanoengineered matrix, fiber bundle model of UD composites with hierarchically clustered fibers and 3D multilevel model of wood considered as a gradient, cellular material with layered composite cell walls. The main areas of research in micromechanics of hierarchical materials are identified, among them, the...

  2. Light as experiential material

    DEFF Research Database (Denmark)

    Søndergaard, Karin; Petersen, Kjell Yngve

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education.......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education....

  3. Alloy catalyst material

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a novel alloy catalyst material for use in the synthesis of hydrogen peroxide from oxygen and hydrogen, or from oxygen and water. The present invention also relates to a cathode and an electrochemical cell comprising the novel catalyst material, and the process use...

  4. MULTISCALE PHENOMENA IN MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    A. BISHOP

    2000-09-01

    This project developed and supported a technology base in nonequilibrium phenomena underpinning fundamental issues in condensed matter and materials science, and applied this technology to selected problems. In this way the increasingly sophisticated synthesis and characterization available for classes of complex electronic and structural materials provided a testbed for nonlinear science, while nonlinear and nonequilibrium techniques helped advance our understanding of the scientific principles underlying the control of material microstructure, their evolution, fundamental to macroscopic functionalities. The project focused on overlapping areas of emerging thrusts and programs in the Los Alamos materials community for which nonlinear and nonequilibrium approaches will have decisive roles and where productive teamwork among elements of modeling, simulations, synthesis, characterization and applications could be anticipated--particularly multiscale and nonequilibrium phenomena, and complex matter in and between fields of soft, hard and biomimetic materials. Principal topics were: (i) Complex organic and inorganic electronic materials, including hard, soft and biomimetic materials, self-assembly processes and photophysics; (ii) Microstructure and evolution in multiscale and hierarchical materials, including dynamic fracture and friction, dislocation and large-scale deformation, metastability, and inhomogeneity; and (iii) Equilibrium and nonequilibrium phases and phase transformations, emphasizing competing interactions, frustration, landscapes, glassy and stochastic dynamics, and energy focusing.

  5. 75 FR 68384 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2010-11-05

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of Opening of Additional Materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  6. 76 FR 27092 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2011-05-10

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of opening of additional materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  7. 76 FR 62856 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2011-10-11

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of opening of additional materials. SUMMARY: This notice announces the opening of Nixon Presidential Historical Materials by the Richard Nixon...

  8. 77 FR 58179 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2012-09-19

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration ACTION: Notice of opening of additional materials SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  9. 77 FR 31400 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2012-05-25

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of Opening of Additional Materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  10. 76 FR 35918 - Nixon Presidential Historical Materials; Opening of Materials

    Science.gov (United States)

    2011-06-20

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials; Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of Opening of Additional Materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  11. 78 FR 42805 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2013-07-17

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ] ACTION: Notice of Opening of Additional Nixon Materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the...

  12. 75 FR 30863 - Nixon Presidential Historical Materials: Opening of Materials

    Science.gov (United States)

    2010-06-02

    ... RECORDS ADMINISTRATION Nixon Presidential Historical Materials: Opening of Materials AGENCY: National Archives and Records Administration. ACTION: Notice of opening of additional materials. SUMMARY: This notice announces the opening of additional Nixon Presidential Historical Materials by the Richard...

  13. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  14. Recycling fusion materials

    International Nuclear Information System (INIS)

    The inherent safety and environmental advantages of fusion power in comparison with other energy sources play an important role in the public acceptance. No waste burden for future generations is therefore one of the main arguments to decide for fusion power. The waste issue has thus been studied in several documents and the final conclusion of which it is stated that there is no permanent disposal waste needed if recycling is applied. But recycling of fusion reactor materials is far to be obvious regarding mostly the very high specific activity of the materials to be handled, the types of materials and the presence of tritium. The main objective of research performed by SCK-CEN is to study the possible ways of recycling fusion materials and analyse the challenges of the materials management from fusion reactors, based on current practices used in fission reactors and the requirements for the manufacture of fusion equipment

  15. Fusion Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    The objective of SCK-CEN's programme on fusion reactor materials is to contribute to the knowledge on the radiation-induced behaviour of fusion reactor materials and components as well as to help the international community in building the scientific and technical basis needed for the construction of the future reactor. Ongoing projects include: the study of the mechanical and chemical (corrosion) behaviour of structural materials under neutron irradiation and water coolant environment; the investigation of the characteristics of irradiated first wall material such as beryllium; investigations on the management of materials resulting from the dismantling of fusion reactors including waste disposal. Progress and achievements in these areas in 2001 are discussed.

  16. Rupture of materials

    International Nuclear Information System (INIS)

    The aim of this work is to give a concrete knowledge of the rupture mechanisms of materials. The following points are most particularly detailed: 1)the means used for examining the ruptures 2)the phenomena generating defects in the structures and the mechanical concepts allowing to quantify the local solicitations they induce (mechanics of rupture) 3)the physical mechanisms which lead to the rupture of a material: theoretical rupture, ductile rupture, cleavage, tearing, fatigue and environment effects: stress corrosion, fatigue by corrosion, hydrogen embrittlement, creep...The materials considered are mainly metals and metallic alloys as well as ceramics, glasses or polymers. Some advices to follow in presence of defects and the methods of calculation of materials lifetime are given too. This book is particularly intended to students or engineers already familiarized with materials science and which would deepen the specific phenomena leading to ruptures. (O.M.)

  17. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  18. Lasers in materials science

    CERN Document Server

    Ossi, Paolo; Zhigilei, Leonid

    2014-01-01

    This book covers various aspects of lasers in materials science, including a comprehensive overview on basic principles of laser-materials interactions and applications enabled by pulsed laser systems.  The material is organized in a coherent way, providing the reader with a harmonic architecture. While systematically covering the major current and emerging areas of lasers processing applications, the Volume provides examples of targeted modification of material properties achieved through careful control of the processing conditions and laser irradiation parameters. Special emphasis is placed on specific strategies aimed at nanoscale control of material structure and properties to match the stringent requirements of modern applications.  Laser fabrication of novel nanomaterials, which expands to the domains of photonics, photovoltaics, sensing, and biomedical applications, is also discussed in the Volume. This book assembles chapters based on lectures delivered at the Venice International School on Lasers...

  19. Combinatorial materials synthesis

    Directory of Open Access Journals (Sweden)

    Ichiro Takeuchi

    2005-10-01

    Full Text Available The pace at which major technological changes take place is often dictated by the rate at which new materials are discovered, and the timely arrival of new materials has always played a key role in bringing advances to our society. It is no wonder then that the so-called combinatorial or high-throughput strategy has been embraced by practitioners of materials science in virtually every field. High-throughput experimentation allows simultaneous synthesis and screening of large arrays of different materials. Pioneered by the pharmaceutical industry, the combinatorial method is now widely considered to be a watershed in accelerating the discovery and optimization of new materials1–5.

  20. Materials and nanotechnology

    International Nuclear Information System (INIS)

    The focus of the Materials and Nanotechnology Program is technology development related to processing, analysis, testing and characterization of materials in general. These are achieved through execution of R&D projects in engineering and materials science, cooperative projects with private and public sector companies, universities and other research institutes. Besides technology development, this Program also fosters training and human resource development in association with the University of São Paulo and many industrial sectors. This Program is divided into sub-programs in broad areas such as ceramic, composite and metallic materials as well as characterization of physical and chemical properties of materials. The sub-programs are further divided into general topics and within each topic, R&D projects. A brief description of progress in each topic during the last three years follows. (author)

  1. Ferroelectricity in antiferroelectric NaNbO.sub.3./sub. crystal

    Czech Academy of Sciences Publication Activity Database

    Tyunina, Marina; Dejneka, Alexandr; Rytz, D.; Gregora, Ivan; Borodavka, Fedir; Vondráček, Martin; Honolka, Jan

    2014-01-01

    Roč. 26, č. 12 (2014), s. 1-8. ISSN 0953-8984 Institutional support: RVO:68378271 Keywords : sodium niobate * ferroelectric * optical Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.346, year: 2014

  2. Dynamic mechanism of the ferroelectric to antiferroelectric phase transition in chiral smectic liquid crystals

    OpenAIRE

    VIJ, JAGDISH; Fukuda, Atsuo; Song, Jang-Kun

    2008-01-01

    PUBLISHED We report on the observation of V-shaped switching in a ferroelectric liquid crystal cell over a wide range of temperatures. Results of the optical transmittance in the visible region give us the helical pitch for various temperatures of the ferroelectric liquid crystalline compound used. We show that the helical pitch, in addition to the spontaneous polarization (PS) and thickness of the alignment layer of the cell, is an important factor in giving V-shaped switching. A longer o...

  3. Security of material

    International Nuclear Information System (INIS)

    Full text: From the early days of discovery and experimentation with nuclear science, nuclear and radioactive materials have held extraordinary potential for being of great benefit to humankind, as well as for causing significant harm. For the past forty years, the IAEA has played an important role in ensuring that nuclear technologies and materials are used only for peaceful purposes. The Agency's safeguards programme has been providing assurances that States honour their undertakings to use nuclear facilities and materials for peaceful purposes only. The potential of nuclear materials and other radioactive materials being used in subversive activities, such as theft, illicit trafficking, sabotage and threats thereof, has been recognized by the international community. The tragic events in New York have given new light to and increased concern for this potential. No target may be considered immune from terrorism. Since 1993, States have confirmed over 370 cases of illicit trafficking. Information is also available on potential attempts of and actual acts of sabotage. For any State, the first step in ensuring the security of their materials is an effective national system. Such a system must contain multiple elements, including physical protection measures, material accountability arrangements, reliable detection capabilities, and plans for rapid and effective response when material is found to be lost, stolen or otherwise not under proper control. The system must also cover illegal waste dumping and other activities that would result in the release of radioactive material into the environment. All these measures should be based on well founded legal and regulatory structures. In many cases, the responsibility for these various elements lies with different bodies, and co-operation between them is vital to the success of the national system. The Agency's programme Security of Material aims at being of service to States in their efforts to upgrade their security

  4. Materials at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Antoinette J [Los Alamos National Laboratory

    2010-01-01

    Exploring the physics, chemistry, and metallurgy of materials has been a primary focus of Los Alamos National Laboratory since its inception. In the early 1940s, very little was known or understood about plutonium, uranium, or their alloys. In addition, several new ionic, polymeric, and energetic materials with unique properties were needed in the development of nuclear weapons. As the Laboratory has evolved, and as missions in threat reduction, defense, energy, and meeting other emerging national challenges have been added, the role of materials science has expanded with the need for continued improvement in our understanding of the structure and properties of materials and in our ability to synthesize and process materials with unique characteristics. Materials science and engineering continues to be central to this Laboratory's success, and the materials capability truly spans the entire laboratory - touching upon numerous divisions and directorates and estimated to include >1/3 of the lab's technical staff. In 2006, Los Alamos and LANS LLC began to redefine our future, building upon the laboratory's established strengths and promoted by strongly interdependent science, technology and engineering capabilities. Eight Grand Challenges for Science were set forth as a technical framework for bridging across capabilities. Two of these grand challenges, Fundamental Understanding of Materials and Superconductivity and Actinide Science. were clearly materials-centric and were led out of our organizations. The complexity of these scientific thrusts was fleshed out through workshops involving cross-disciplinary teams. These teams refined the grand challenge concepts into actionable descriptions to be used as guidance for decisions like our LDRD strategic investment strategies and as the organizing basis for our external review process. In 2008, the Laboratory published 'Building the Future of Los Alamos. The Premier National Security Science Laboratory

  5. NSUF Irradiated Materials Library

    Energy Technology Data Exchange (ETDEWEB)

    Cole, James Irvin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

  6. Professional Nuclear Materials Management

    International Nuclear Information System (INIS)

    This paper describes the scope of nuclear materials management for a typical power reactor in the United States of America. Since this power reactor is financed by private capital, one of the principal obligations of the reactor operator is to ensure that the investment is protected and will furnish an adequate financial return. Because of the high intrinsic value of nuclear materials, appropriate security and accountability must be continually exercised to minimize losses beyond security and accountability for the nuclear materials. Intelligent forethought and planning must be employed to ensure that additional capital is not lost as avoidable additional costs or loss of revenue in a number of areas. The nuclear materials manager must therefore provide in advance against the following contingencies and maintain constant control or liaison against deviations from planning during (a) pre-reactor acquisition of fuel and fuel elements, (b) in-reactor utilization of the fuel elements, and (c) post-reactor recovery of fuel values. During pre-reactor planning and operations, it is important that the fuel element be designed for economy in manufacture, handling, shipping, and replaceability. The time schedule for manufacturing operations must minimize losses of revenue from unproductive dead storage of high cost materials. For in-reactor operations, the maximum achievable burn-up of the fissionable material must be obtained by means of appropriate fuel rearrangement schemes. Concurrently the unproductive down-time of the reactor for fuel rearrangement, inspections, and the like must be minimized. In the post-reactor period, when the fuel has reached a predetermined depletion of fissionable material, the nuclear materials manager must provide for the most economical reprocessing and recovery of fissionable values and by-products. Nuclear materials management is consequently an essential factor in achieving competitive fuel cycle and unit energy costs with power reactors

  7. High temperature materials

    International Nuclear Information System (INIS)

    The aim of this workshop is to share the needs of high temperature and nuclear fuel materials for future nuclear systems, to take stock of the status of researches in this domain and to propose some cooperation works between the different research organisations. The future nuclear systems are the very high temperature (850 to 1200 deg. C) gas cooled reactors (GCR) and the molten salt reactors (MSR). These systems include not only the reactor but also the fabrication and reprocessing of the spent fuel. This document brings together the transparencies of 13 communications among the 25 given at the workshop: 1) characteristics and needs of future systems: specifications, materials and fuel needs for fast spectrum GCR and very high temperature GCR; 2) high temperature materials out of neutron flux: thermal barriers: materials, resistance, lifetimes; nickel-base metal alloys: status of knowledge, mechanical behaviour, possible applications; corrosion linked with the gas coolant: knowledge and problems to be solved; super-alloys for turbines: alloys for blades and discs; corrosion linked with MSR: knowledge and problems to be solved; 3) materials for reactor core structure: nuclear graphite and carbon; fuel assembly structure materials of the GCR with fast neutron spectrum: status of knowledge and ceramics and cermets needs; silicon carbide as fuel confinement material, study of irradiation induced defects; migration of fission products, I and Cs in SiC; 4) materials for hydrogen production: status of the knowledge and needs for the thermochemical cycle; 5) technologies: GCR components and the associated material needs: compact exchangers, pumps, turbines; MSR components: valves, exchangers, pumps. (J.S.)

  8. Reliability of construction materials

    International Nuclear Information System (INIS)

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW)

  9. Materials for Fusion Applications

    Czech Academy of Sciences Publication Activity Database

    Matějíček, Jiří

    2013-01-01

    Roč. 53, č. 2 (2013), s. 197-212. ISSN 1210-2709. [Symposium on Plasma Physics and Technology/25./. Praha, 18.06.2012-21.06.2012] R&D Projects: GA ČR(CZ) GAP108/12/1872; GA MŠk 7G10072 Institutional research plan: CEZ:AV0Z20430508 Keywords : nuclear fusion * materials * plasma facing components * plasma-material interaction * functionally graded materials Subject RIV: BL - Plasma and Gas Discharge Physics http://ctn.cvut.cz/ap/download.php?id=797

  10. Investigating Encrypted Material

    Science.gov (United States)

    McGrath, Niall; Gladyshev, Pavel; Kechadi, Tahar; Carthy, Joe

    When encrypted material is discovered during a digital investigation and the investigator cannot decrypt the material then s/he is faced with the problem of how to determine the evidential value of the material. This research is proposing a methodology of extracting probative value from the encrypted file of a hybrid cryptosystem. The methodology also incorporates a technique for locating the original plaintext file. Since child pornography (KP) images and terrorist related information (TI) are transmitted in encrypted format the digital investigator must ask the question Cui Bono? - who benefits or who is the recipient? By doing this the scope of the digital investigation can be extended to reveal the intended recipient.

  11. Materials science and engineering

    Energy Technology Data Exchange (ETDEWEB)

    Holden, T.M.

    1995-10-01

    The science-based stockpile stewardship program emphasizes a better understanding of how complex components function through advanced computer calculations. Many of the problem areas are in the behavior of materials making up the equipment. The Los Alamos Neutron Science Center (LANSCE) can contribute to solving these problems by providing diagnostic tools to examine parts noninvasively and by providing the experimental tools to understand material behavior in terms of both the atomic structure and the microstructure. Advanced computer codes need experimental information on material behavior in response to stress, temperature, and pressure as input, and they need benchmarking experiments to test the model predictions for the finished part.

  12. Chemicals in material cycles

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Eriksson, Eva; Astrup, Thomas Fruergaard

    2015-01-01

    Material recycling has been found beneficial in terms of resource and energy performance and is greatly promoted throughout the world. A variety of chemicals is used in materials as additives and data on their presence is sparse. The present work dealt with paper as recyclable material and...... diisobutyl phthalate (DiBP) as chemical in focus. The results showed variations, between 0.83 and 32 μg/g, in the presence of DiBP in Danish waste paper and board and potential accumulation due to recycling....

  13. Advanced Aircraft Material

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Prince

    2013-06-01

    Full Text Available There has been long debate on “advanced aircraft material” from past decades & researchers too came out with lots of new advanced material like composites and different aluminum alloys. Now days a new advancement that is in great talk is third generation Aluminum-lithium alloy. Newest Aluminum-lithium alloys are found out to have low density, higher elastic modulus, greater stiffness, greater cryogenic toughness, high resistance to fatigue cracking and improved corrosion resistance properties over the earlier used aircraft material as mentioned in Table 3 [1-5]. Comparison had been made with nowadays used composite material and is found out to be more superior then that

  14. Energy harvesting materials

    CERN Document Server

    Andrews, David L

    2005-01-01

    The science of energy harvesting materials is experiencing phenomenal growth and attracting huge interest. Exploiting recently acquired insights into the fundamental mechanisms and principles of photosynthesis, it is now possible to forge entirely new and distinctive molecular materials and devise artificial photosystems and applications far remote from conventional solar cell technology. In this comprehensive treatment of energy harvesting, a team of internationally acclaimed scientists at the forefront of the subject paint a state-of-the-art picture of modern energy harvesting materials scie

  15. ATS materials/manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Karnitz, M.A.; Wright, I.G.; Ferber, M.K. [and others

    1997-11-01

    The Materials/Manufacturing Technology subelement is a part of the base technology portion of the Advanced Turbine Systems (ATS) Program. The work in this subelement is being performed predominantly by industry with assistance from national laboratories and universities. The projects in this subelement are aimed toward hastening the incorporation of new materials and components in gas turbines. Work is currently ongoing on thermal barrier coatings (TBCs), the scale-up of single crystal airfoil manufacturing technologies, materials characterization, and technology information exchange. This paper presents highlights of the activities during the past year. 12 refs., 24 figs., 4 tabs.

  16. Materials response to irradiation

    International Nuclear Information System (INIS)

    Radiation-induced changes in the mechanical properties of metals, e.g. due to the embrittlement necessitate irradiation experiments with HTR-specific neutron spectra. These experiments help to determine materials behaviour and establish basic data for design and safety testing, especially with a view to the high fluence and temperature loads on absorber cans. The experiments are carried out up to maximum operational fluence (>= 1022nsub(th)/cm2). Results so far have shown the importance of the materials structure for assurance of sufficient residual ductility after irradiation. Secondary experiments, e.g. on He implantation and radiation response of the absorber material B4C, are mentioned. (orig.)

  17. Advanced healthcare materials

    CERN Document Server

    Tiwari, Ashutosh

    2014-01-01

    Advanced materials are attracting strong interest in the fundamental as well as applied sciences and are being extensively explored for their potential usage in a range of healthcare technological and biological applications. Advanced Healthcare Nanomaterials summarises the current status of knowledge in the fields of advanced materials for functional therapeutics, point-of-care diagnostics, translational materials, up and coming bio-engineering devices. The book highlights the key features which enable engineers to design stimuli-responsive smart nanoparticles, novel biomaterials, nan

  18. Mechanics of soft materials

    CERN Document Server

    Volokh, Konstantin

    2016-01-01

    This book provides a concise introduction to soft matter modelling. It offers an up-to-date review of continuum mechanical description of soft and biological materials from the basics to the latest scientific materials. It includes multi-physics descriptions, such as chemo-, thermo-, electro- mechanical coupling. It derives from a graduate course at Technion that has been established in recent years. It presents original explanations for some standard materials and features elaborated examples on all topics throughout the text. PowerPoint lecture notes can be provided to instructors. .

  19. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    SCK-CEN's research and development programme on fusion reactor materials includes: (1) the study of the mechanical behaviour of structural materials under neutron irradiation (including steels, inconel, molybdenum, chromium); (2) the determination and modelling of the characteristics of irradiated first wall materials such as beryllium; (3) the detection of abrupt electrical degradation of insulating ceramics under high temperature and neutron irradiation; (4) the study of the dismantling and waste disposal strategy for fusion reactors.; (5) a feasibility study for the testing of blanket modules under neutron radiation. Main achievements in these topical areas in the year 1999 are summarised

  20. Materials science symposium 'materials science using accelerators'

    International Nuclear Information System (INIS)

    The facility of the JAERI-Tokai tandem accelerator and its booster has been contributing to advancing heavy-ion sciences in the fields of nuclear physics, nuclear chemistry, atomic and solid-state physics and materials science, taking advantage of its prominent performance of heavy-ion acceleration. This facility was recently upgraded by changing the acceleration tubes and installing an ECR ion-source at the terminal. The radioactive nuclear beam facility (Tokai Radioactive Ion Accelerator Complex, TRIAC) was also installed by the JAERI-KEK joint project. On this occasion, this meeting was held in order to provide a new step for the advancement of heavy-ion science, and to exchange information on recent activities and future plans using the tandem facility as well as on promising new experimental techniques. This meeting was held at Tokai site of JAERI on January 6th and 7th in 2005, having 24 oral presentations, and was successfully carried out with as many as 90 participants and lively discussions among scientists from all the fields of heavy-ion science, including solid-sate physics, nuclear physics and chemistry, and accelerator physics. This summary is the proceedings of this meeting. We would like to thank all the staffs of the accelerators section, participants and office workers in the Department of Materials Science for their support. The 24 of the presented papers are indexed individually. (J.P.N.)

  1. Heavy Vehicle Propulsion Materials

    International Nuclear Information System (INIS)

    The objectives are to Provide Key Enabling Materials Technologies to Increase Energy Efficiency and Reduce Exhaust Emissions. The following goals are listed: Goal 1: By 3rd quarter 2002, complete development of materials enabling the maintenance or improvement of fuel efficiency(ge) 45% of class 7-8 truck engines while meeting the EPA/Justice Department ''Consent Decree'' for emissions reduction. Goal 2: By 4th quarter 2004, complete development of enabling materials for light-duty (class 1-2) diesel truck engines with efficiency over 40%, over a wide range of loads and speeds, while meeting EPA Tier 2 emission regulations. Goal 3: By 4th quarter 2006, complete development of materials solutions to enable heavy-duty diesel engine efficiency of 50% while meeting the emission reduction goals identified in the EPA proposed rule for heavy-duty highway engines.''

  2. Quasicrystals: Making invisible materials

    CERN Document Server

    Boriskina, Svetlana V

    2016-01-01

    All-dielectric photonic quasicrystals may act as zero-refractive-index homogeneous materials despite their lack of translational symmetry and periodicity, stretching wavelengths to infinity and offering applications in light wavefront sculpting and optical cloaking.

  3. Nuclear material operations manual

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, R.P.

    1981-02-01

    This manual provides a concise and comprehensive documentation of the operating procedures currently practiced at Sandia National Laboratories with regard to the management, control, and accountability of nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion.

  4. Intelligent Radiative Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An opportunity to boost energy efficiency in homes and buildings exists through the design of functional radiative properties in glass and other building materials....

  5. Materials Sciences Programs

    International Nuclear Information System (INIS)

    A compilation and index of the ERDA materials sciences program is presented. This compilation is intended for use by administrators, managers, and scientists to help coordinate research and as an aid in selecting new programs

  6. Materials Sciences Programs

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    A compilation and index of the ERDA materials sciences program is presented. This compilation is intended for use by administrators, managers, and scientists to help coordinate research and as an aid in selecting new programs. (GHT)

  7. Evaluation of learning materials

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe; Hansen, Thomas Illum

    2011-01-01

    This paper presents a holistic framework for evaluating learning materials and designs for learning. A holistic evaluation comprises investigations of the potential learning potential, the actualized learning potential, and the actual learning. Each aspect is explained and exemplified through...

  8. Mechanics of moving materials

    CERN Document Server

    Banichuk, Nikolay; Neittaanmäki, Pekka; Saksa, Tytti; Tuovinen, Tero

    2014-01-01

    This book deals with theoretical aspects of modelling the mechanical behaviour of manufacturing, processing, transportation or other systems in which the processed or supporting material is travelling through the system. Examples of such applications include paper making, transmission cables, band saws, printing presses, manufacturing of plastic films and sheets, and extrusion of aluminium foil, textiles and other materials.   The work focuses on out-of-plane dynamics and stability analysis for isotropic and orthotropic travelling elastic and viscoelastic materials, with and without fluid-structure interaction, using analytical and semi-analytical approaches.  Also topics such as fracturing and fatigue are discussed in the context of moving materials. The last part of the book deals with optimization problems involving physical constraints arising from the stability and fatigue analyses, including uncertainties in the parameters.   The book is intended for researchers and specialists in the field, providin...

  9. Reversible hydrogen storage materials

    Science.gov (United States)

    Ritter, James A.; Wang, Tao; Ebner, Armin D.; Holland, Charles E.

    2012-04-10

    In accordance with the present disclosure, a process for synthesis of a complex hydride material for hydrogen storage is provided. The process includes mixing a borohydride with at least one additive agent and at least one catalyst and heating the mixture at a temperature of less than about 600.degree. C. and a pressure of H.sub.2 gas to form a complex hydride material. The complex hydride material comprises MAl.sub.xB.sub.yH.sub.z, wherein M is an alkali metal or group IIA metal, Al is the element aluminum, x is any number from 0 to 1, B is the element boron, y is a number from 0 to 13, and z is a number from 4 to 57 with the additive agent and catalyst still being present. The complex hydride material is capable of cyclic dehydrogenation and rehydrogenation and has a hydrogen capacity of at least about 4 weight percent.

  10. Spacecraft Material Outgassing Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This compilation of outgassing data of materials intended for spacecraft use were obtained at the Goddard Space Flight Center (GSFC), utilizing equipment developed...

  11. Nuclear material operations manuals

    International Nuclear Information System (INIS)

    This manual is intended to provide a concise and comprehensive documentation of the operating procedures currently practiced at Sandia Laboratories with regard to the management, control, and accountability of radioactive and nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion

  12. Testing of abrasion materials

    International Nuclear Information System (INIS)

    A method of abrasion testing according to ASTM C 704-76 a is presented for steel fibre concrete mortar, fusion-cast basalt and a surface coating material and results of practical interest are mentioned. Due to the high technical demands on these materials and their specific fields of application, the very first test already supplied interesting findings. From the user's point of view, the method is an interesting alternative to the common test methods, e.g. according to DIN 52 108 (wheel test according to Boehme). In English-speaking countries, testing according to ASTM is often mandatory in the refractory industry in order to assure constant quality of refractory materials after setting. The method is characterized by good comparability and high accuracy of measurement. Only the test piece is exchanged while the test conditions remain constant, so that accurate information on the material studied is obtained. (orig.)

  13. Rapidly processable radiographic material

    International Nuclear Information System (INIS)

    A new rapidly processable radiographic silver halide material is described for use in mammography and non-destructive testing of industrial materials. The radiographic material is used for direct exposure to penetrating radiation without the use of fluorescent-intensifying screens. It consists of a transparent support with a layer of hydrophilic colloid silver halide emulsion on one or both sides. Examples of the preparation of three different silver halide emulsions are given including the use of different chemical sensitizers. These new radiographic materials have good resistance to the formation of pressure marks in rapid processing apparatus and they have improved sensitivity for direct exposure to penetrating radiation compared to conventional radiographic emulsions. (U.K.)

  14. Photoconductivity in Dirac materials

    International Nuclear Information System (INIS)

    Two-dimensional (2D) Dirac materials including graphene and the surface of a three-dimensional (3D) topological insulator, and 3D Dirac materials including 3D Dirac semimetal and Weyl semimetal have attracted great attention due to their linear Dirac nodes and exotic properties. Here, we use the Fermi’s golden rule and Boltzmann equation within the relaxation time approximation to study and compare the photoconductivity of Dirac materials under different far- or mid-infrared irradiation. Theoretical results show that the photoconductivity exhibits the anisotropic property under the polarized irradiation, but the anisotropic strength is different between 2D and 3D Dirac materials. The photoconductivity depends strongly on the relaxation time for different scattering mechanism, just like the dark conductivity

  15. Advanced materials-2005

    International Nuclear Information System (INIS)

    The 9. International Symposium on Advanced Materials (ISAM) was held from 19-22 September, 2005. This popular biennial event is one of the prime international forums in South Asia where material scientists and engineers can keep abreast with recent technologies involving advanced structural and functional materials. The technical committee of ISAM received 213 papers, 49 from abroad 164 from within the country. These papers were submitted in response to five important topics; i) Processing, Production and Developments, ii) Surface Engineering, iii) Phase Transformation and Characterization, iv) Advances in Magnetic Materials and v) Reliability and Life Assessment. The proceedings of the 9. ISAM consists of 108 reviewed papers. This symposium provided an ideal opportunity for exchange of information amongst scientists, engineers, and researchers. (A.B.)

  16. Relativistic theories of materials

    CERN Document Server

    Bressan, Aldo

    1978-01-01

    The theory of relativity was created in 1905 to solve a problem concerning electromagnetic fields. That solution was reached by means of profound changes in fundamental concepts and ideas that considerably affected the whole of physics. Moreover, when Einstein took gravitation into account, he was forced to develop radical changes also in our space-time concepts (1916). Relativistic works on heat, thermodynamics, and elasticity appeared as early as 1911. However, general theories having a thermodynamic basis, including heat conduction and constitutive equations, did not appear in general relativity until about 1955 for fluids and appeared only after 1960 for elastic or more general finitely deformed materials. These theories dealt with materials with memory, and in this connection some relativistic versions of the principle of material indifference were considered. Even more recently, relativistic theories incorporating finite deformations for polarizable and magnetizable materials and those in which couple s...

  17. Nuclear material operations manual

    International Nuclear Information System (INIS)

    This manual provides a concise and comprehensive documentation of the operating procedures currently practiced at Sandia National Laboratories with regard to the management, control, and accountability of nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion

  18. Objects, materiality and meaning

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Lindegaard, Hanne

    2008-01-01

    The present research work investigates the relation between physical objects, their materiality, understood as the physical substances they are made from, and the communication from the objects. In product design of physical objects the communicative aspects are just as important as the function...... of the object, and the designers aim is therefore to tune both in order to achieve a desired goal. To do so the designer basically has 2 options: Alteration of the physical shape of the object and the selection of materials. Through the manipulation of shape and materials can symbolic and sensory information...... be written into the object. The materials are therefore carriers of communication, even though this is dependent of the cultural context and the environment which the object will be part of. However the designer has only minor influence on those....

  19. Materials Test Station

    Data.gov (United States)

    Federal Laboratory Consortium — When completed, the Materials Test Station at the Los Alamos Neutron Science Center will meet mission need. MTS will provide the only fast-reactor-like irradiation...

  20. Materials research at CMAM

    International Nuclear Information System (INIS)

    The Centro de Micro Analisis de Materiales (CMAM) is a research centre of the Universidad Autónoma de Madrid dedicated to the modification and analysis of materials using ion beam techniques. The infrastructure, based on a HVEE 5MV tandem accelerator, provided with a coaxial Cockcroft Walton charging system, is fully open to research groups of the UAM, to other public research institutions and to private enterprises. The CMAM research covers a few important lines such as advanced materials, surface science, biomedical materials, cultural heritage, materials for energy production. The Centre gives as well support to university teaching and technical training. A detail description of the research infrastructures and their use statistics will be given. Some of the main research results will be presented to show the progress of research in the Centre in the past few years and to motivate the strategic plans for the forthcoming

  1. Materials engineering data base

    Science.gov (United States)

    1995-01-01

    The various types of materials related data that exist at the NASA Marshall Space Flight Center and compiled into databases which could be accessed by all the NASA centers and by other contractors, are presented.

  2. 2002 materials report

    International Nuclear Information System (INIS)

    This report is the very first devoted to the researches carried out in all centres of the French atomic energy commission (CEA) in the domain of materials. Each material, technology or process is presented with some explanations. The report is divided in three chapters dealing with: 1 - the nano-materials and the engineering of surfaces: surface functionalization (new coatings for cutting tools, new CVD process for the deposition of carbon nano-tubes, nano-structured metallic films, polymerization by gaseous phase deposition, electro-chromium systems, functional coatings by sol-gel process, sol-gel processing of optical fibers, modeling of the plasma projection process); nano-particulates and emerging materials (synthesis of SiCN nano-particulates by laser pyrolysis, hot-forming of Si/C/N/O nano-metric powders by isostatic compression, synthesis of aligned carbon nano-tubes by pyrolysis of mixed aerosols, elaboration and characterization of new oxide-type materials in supercritical CO2 phase, fluorescent semiconductor nano-crystals for labelling, fibrillary proteins and their behaviour at interfaces); 2 - materials engineering and numerical materials (simulation of the welding process by YAG laser pulses, welded joints reliability, control of precipitation microstructures by the addition of nucleating agents, optimization of pressing cycles for the forming of industrial parts by matrix compaction, mechanical and thermal pre-dimensioning of thermo-structural composites, modeling of the behaviour of thermo-structural composites, joints follow up system for innovative welding control process); joining technologies (feasibility study for the fabrication by diffusion welding of the first wall panels of ITER reactor, welding of spent fuel containers for long lasting storage, electron beam welding of aluminium 6061 and hot cracking risk, hybrid welding technology, heat source model for TIG welding, cladding of the amplifying plates of the Megajoule laser facility

  3. Thermal barrier coating materials

    OpenAIRE

    Clarke, David R.; Simon R. Phillpot

    2005-01-01

    Improved thermal barrier coatings (TBCs) will enable future gas turbines to operate at higher gas temperatures. Considerable effort is being invested, therefore, in identifying new materials with even better performance than the current industry standard, yttria-stabilized zirconia (YSZ). We review recent progress and suggest that an integrated strategy of experiment, intuitive arguments based on crystallography, and simulation may lead most rapidly to the development of new TBC materials.

  4. Material Nuclear Culture, Exhibition

    OpenAIRE

    Carpenter, Ele; Mabb, David; Craighead, Alison; Crowe, Nick; Schuppli, Susan; Takeuchi, Kota; Erika, Kobayashi

    2016-01-01

    Material Nuclear Culture is an exhibition of contemporary artists responses to the physical qualities and material traces of the aesthetics, traditions and legacy of nuclear powered submarines in the UK. Whilst the MOD is currently undertaking a public consultation process on how and where to dismantle and store Britain’s old subs the long term problems of storing radioactive waste remain unresolved. The exhibition will include new sculptural, film, sound and installation works by David ...

  5. A new material practice

    DEFF Research Database (Denmark)

    Tamke, Martin; Nicholas, Paul; Ramsgaard Thomsen, Mette

    2012-01-01

    The first generation of digital architecture was fascinated with the extension of digital possibilities into the physical world. Today, we are seeing the emergence of a new material practice. This practice is focusing on a design and production process that is seeking an understanding of the...... aggregated behavior of matter in an environment. Advances in material science and in computational tools are creating new opportunities within architectural design. However, these approaches are challenging the current practices of design and representation....

  6. A new material practice

    OpenAIRE

    Tamke, Martin; Nicholas, Paul; Ramsgaard Thomsen, Mette

    2012-01-01

    The first generation of digital architecture was fascinated with the extension of digital possibilities into the physical world. Today, we are seeing the emergence of a new material practice. This practice is focusing on a design and production process that is seeking an understanding of the aggregated behavior of matter in an environment. Advances in material science and in computational tools are creating new opportunities within architectural design. However, these approaches are challengi...

  7. Modeling multiphase materials processes

    CERN Document Server

    Iguchi, Manabu

    2010-01-01

    ""Modeling Multiphase Materials Processes: Gas-Liquid Systems"" describes the methodology and application of physical and mathematical modeling to multi-phase flow phenomena in materials processing. The book focuses on systems involving gas-liquid interaction, the most prevalent in current metallurgical processes. The performance characteristics of these processes are largely dependent on transport phenomena. This volume covers the inherent characteristics that complicate the modeling of transport phenomena in such systems, including complex multiphase structure, intense turbulence, opacity of

  8. Beam-Material Interaction

    CERN Document Server

    Mokhov, N V

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  9. Nano-composite materials

    Science.gov (United States)

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  10. Introduction to radioactive materials

    International Nuclear Information System (INIS)

    The purpose of this chapter is to provide the researcher with basic information on the physics of radioactive materials and the nature and detection of radiations emitted by these materials. A detailed knowledge of nuclear structure and radiation physics is not needed for most radioisotope applications, but a basic understanding of these subjects is essential for proper choice of radiation detection instrumentation and radiation protection methods for a specific experimental procedure. (author)

  11. Auxetic materials and structures

    CERN Document Server

    Lim, Teik-Cheng

    2015-01-01

    This book describes the fundamentals of the mechanics and design of auxetic solids and structures, which possess a negative Poisson’s ratio. It will benefit two groups of readers: (a) industry practitioners, such as product and structural designers, who need to control mechanical stress distributions using auxetic materials, and (b) academic researchers and students who intend to produce structures with unique mechanical and other physical properties using auxetic materials.

  12. Transport of radioactive materials

    International Nuclear Information System (INIS)

    The purpose of this Norm is to establish, relating to the TRANSPORT OF RADIOACTIVE MATERIALS, safety and radiological protection requirements to ensure an adequate control level of the eventual exposure of persons, properties and environment to the ionizing radiation comprising: specifications on radioactive materials for transport; package type selection; specification of the package design and acceptance test requirements; arrangements relating to the transport itself; administrative requirements and responsibilities. (author)

  13. Food Packaging Materials

    Science.gov (United States)

    1978-01-01

    The photos show a few of the food products packaged in Alure, a metallized plastic material developed and manufactured by St. Regis Paper Company's Flexible Packaging Division, Dallas, Texas. The material incorporates a metallized film originally developed for space applications. Among the suppliers of the film to St. Regis is King-Seeley Thermos Company, Winchester, Ma'ssachusetts. Initially used by NASA as a signal-bouncing reflective coating for the Echo 1 communications satellite, the film was developed by a company later absorbed by King-Seeley. The metallized film was also used as insulating material for components of a number of other spacecraft. St. Regis developed Alure to meet a multiple packaging material need: good eye appeal, product protection for long periods and the ability to be used successfully on a wide variety of food packaging equipment. When the cost of aluminum foil skyrocketed, packagers sought substitute metallized materials but experiments with a number of them uncovered problems; some were too expensive, some did not adequately protect the product, some were difficult for the machinery to handle. Alure offers a solution. St. Regis created Alure by sandwiching the metallized film between layers of plastics. The resulting laminated metallized material has the superior eye appeal of foil but is less expensive and more easily machined. Alure effectively blocks out light, moisture and oxygen and therefore gives the packaged food long shelf life. A major packaging firm conducted its own tests of the material and confirmed the advantages of machinability and shelf life, adding that it runs faster on machines than materials used in the past and it decreases product waste; the net effect is increased productivity.

  14. Hemicellulose as barrier material

    OpenAIRE

    Jonas, Hartman

    2006-01-01

    Polysaccharides constitute an important source of raw materials for the packaging industry today. Polysaccharides have good natural barrier properties which are necessary for packaging films. Cellulose is the forerunner among renewable polymers for such applications. Hemicelluloses represent a new interesting breed of barrier materials. We have chosen to work with the hemicellulose O-acetyl-galactoglucomannan (AcGGM). The high water solubility of this particular hemicellulose extracted from p...

  15. Designing with residual materials

    OpenAIRE

    Walhout, W.; Wever, R; Blom, E.; Addink-Dölle, L.; Tempelman, E.

    2013-01-01

    Many entrepreneurial businesses have attempted to create value based on the residual material streams of third parties. Based on ‘waste’ materials they designed products, around which they built their company. Such activities have the potential to yield sustainable products. Many of such companies remain in the more artistic domain, with relatively labor-intensive products, and small batch sizes. Moving beyond such small-scale activities would likely require a standardized innovation process....

  16. Spintronics and functional materials

    Directory of Open Access Journals (Sweden)

    C.H. Marrows

    2009-07-01

    Full Text Available The understanding of electronic behaviour in systems with reduced dimensionality and length scale is a central theme of contemporary condensed matter physics. The unique capabilities of neutron scattering make it an ideal method to study the atomic and molecular, chemical and magnetic structure of a wide class of materials. In this review we highlight recent studies where neutron techniques have been applied to emergent materials and look forward to the possibilities enabled by instrumentation on the ISIS Second Target Station.

  17. Physically Functional Materials

    DEFF Research Database (Denmark)

    2002-01-01

    The invention relates to novel monodisperse or polydisperse compounds, in general named DNO (diamino acid Nalpha-substituted oligopeptides), preferably low molecular weight polypeptides, e.g., based on ornithine, lysine, diaminobutyric acid, diaminopropionic acid, aminoethylglycine or other amino......, photorefractive materials, or materials in which light-induced conformational changes can be produced. Optical anisotropy may reversibly be generated with polarized laser light whereby a hologram is formed. First order diffraction efficiencies of up to around 80% have been obtained....

  18. Biomimetic hydrogel materials

    Science.gov (United States)

    Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

    2000-01-01

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  19. Nanostructured Materials for Magnetoelectronics

    CERN Document Server

    Mikailzade, Faik

    2013-01-01

    This book provides an up-to-date review of nanometer-scale magnetism and focuses on the investigation of the basic properties of magnetic nanostructures. It describes a wide range of physical aspects together with theoretical and experimental methods. A broad overview of the latest developments in this emerging and fascinating field of nanostructured materials is given with emphasis on the practical understanding and operation of submicron devices based on nanostructured magnetic materials.

  20. Ceramic Laser Materials

    Energy Technology Data Exchange (ETDEWEB)

    Soules, T F; Clapsaddle, B J; Landingham, R L; Schaffers, K I

    2005-02-15

    Transparent ceramic materials have several major advantages over single crystals in laser applications, not the least of which is the ability to make large aperture parts in a robust manufacturing process. After more than a decade of working on making transparent YAG:Nd, Japanese workers have recently succeeded in demonstrating samples that performed as laser gain media as well as their single crystal counterparts. Since then several laser materials have been made and evaluated. For these reasons, developing ceramic laser materials is the most exciting and futuristic materials topic in today's major solid-state laser conferences. We have established a good working relationship with Konoshima Ltd., the Japanese producer of the best ceramic laser materials, and have procured and evaluated slabs designed by us for use in our high-powered SSHCL. Our measurements indicate that these materials will work in the SSHCL, and we have nearly completed retrofitting the SSHCL with four of the largest transparent ceramic YAG:Nd slabs in existence. We have also begun our own effort to make this material and have produced samples with various degrees of transparency/translucency. We are in the process of carrying out an extensive design-of-experiments to establish the significant process variables for making transparent YAG. Finally because transparent ceramics afford much greater flexibility in the design of lasers, we have been exploring the potential for much larger apertures, new materials, for example for the Mercury laser, other designs for SSHL, such as, edge pumping designs, slabs with built in ASE suppression, etc. This work has just beginning.

  1. Nuclear Material Management Abstract

    International Nuclear Information System (INIS)

    Nevada Test Site (NTS) has transitioned from its historical and critical role of weapons testing to another critical role for the nation. This new role focuses on being a integral element in solving the multiple challenges facing the National Nuclear Security Administration (NNSA) with nuclear material management. NTS is positioned to be a solution for other NNSA sites challenged with safe nuclear materials storage and disposition. NNSA, with site involvement, is currently transforming the nuclear stockpile and supporting infrastructure to meet the 2030 vision. Efforts are under way to consolidate and modernize the production complex . With respect to the nuclear material stockpile, the NNSA sites are currently reducing the complex nuclear material inventory through disposition and consolidation. This includes moving material from other sites to NTS. State of the art nuclear material management and control practices at NTS are essential for NTS to ensure that assigned activities are accomplished in a safe, secure, efficient, and environmentally responsible manner. NTS activities and challenges will be addressed

  2. Nano-scale materials

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, J.; Smith, D.C.; Devlin, D.J.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Highly selective, alumina-supported molybdenum carbonitrides were prepared by solution impregnation using the metal amide Mo{sub 2}(N(CH{sub 3}){sub 2}){sub 6} as a molecular precursor. On the basis of relative weight percents, these materials demonstrate a 5- to 8-fold increase in catalytic activity over similar materials prepared by traditional solid-state approaches. The catalytic activities of these materials are very dependent upon the type of alumina support used. Impregnation of Mo{sub m}C{sub x}N{sub y} into preformed alumina pellets resulted in a material that specifically isomerized n-heptane into equal amounts of 2- and 3-methylhexanes, as well as iso-butane. No evidence of aromatic products was observed at operating temperatures below 420{degrees}C. The product selectivity of the isomers was 56% at a n-heptane conversion efficiency of 57%. Impregnating Mo{sub m}C{sub x}N{sub y} into an alumina powder resulted in an extremely selective aromatized and dehydrogenated material. The products from this material consist only of aromatics and n-heptenes with less than 2% isomerization or cracking products.

  3. Shape memory materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Compared with piezoelectric ceramics and magnetostrictive materials, the shape memory materials possess larger recoverable strain and recovery stress but slower response to external field. It is expected that the magneto-shape memory materials may develop considerable strain as well as rapid and precise shape control. Pseudoelasticity and shape memory effect (SME) resulted from martensitic transformation and its reverse transformation in shape memory materials were generally described. The requirements of appearing the shape memory effect in materials and the criteria for thermoelastic martensitic transformation were given. Some aspects concerning characteristics of martensitic transformation, and factors affecting SME in Ni-Ti, Cu-Zn-Al and Fe-Mn-Si based alloys as well as ZrO2 containing ceramics were briefly reviewed. Thermodynamic calculation of Ms temperature as function of grain size and parent ordering in Cu-Zn-Al was presented. The works on prediction of Ms in Fe-Mn-Si based alloys and in ZrO2-CeO2 were mentioned. Magnetic shape memory materials were briefly introduced.

  4. LDEF materials data bases

    Science.gov (United States)

    Funk, Joan G.; Strickland, John W.; Davis, John M.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) and the accompanying experiments were composed of and contained a wide variety of materials representing the largest collection of materials flown in low Earth orbit (LEO) and retrieved for ground based analysis to date. The results and implications of the mechanical, thermal, optical, and electrical data from these materials are the foundation on which future LEO space missions will be built. The LDEF Materials Special Investigation Group (MSIG) has been charged with establishing and developing data bases to document these materials and their performance to assure not only that the data are archived for future generations but also that the data are available to the spacecraft user community in an easily accessed, user-friendly form. This paper discusses the format and content of the three data bases developed or being developed to accomplish this task. The hardware and software requirements for each of these three data bases are discussed along with current availability of the data bases. This paper also serves as a user's guide to the MAPTIS LDEF Materials Data Base.

  5. EDITORIAL: Materially speaking!

    Science.gov (United States)

    Cornwall, Malcolm G.

    1997-05-01

    We live in a highly materialistic age. This is true not only for our spiritual outlook - or lack of it - but undeniably so for the physical world in which we live. Materials, which are the feature of this special issue, provide literally the fabric on which the modern world is built. Materials science is the systematic study of the physical properties and behaviour of solids with practical applications and importance (if the utility of the material is not explicit or important we are probably in the realm of solid state physics!). Materials in this sense are the stuff of which cars and computers, jet aircraft and washing machines, tower blocks and saucepans, bridges and golf clubs are made. The science of materials therefore encompasses most of the things that form the infrastructure of modern life. But perhaps it is its very ubiquity that removes the mystique, the glamour, the 'zing' from the subject. In contrast, anything cosmological, astronomical or 'fundamental' (as in 'particle'), i.e. of little or no practical significance to our day-to-day lives, excites the curiosity of many able young people. Witness the profusion of books about galaxies and black holes, and quarks and GUTs which strain the popular science shelves of the bookshops. I'm probably being heretical, but perhaps the over-hyping of the very large and the very small has indeed attracted the able few into the serious study of physics, but because of its inherent mathematical complexity and esoteric remoteness maybe it has put off the average youngster who would nevertheless enjoy and succeed in physics-based higher education (and, not incidentally, help fill the seriously depleted lecture theatres in many university physics - and engineering - departments). Materials science on the other hand deals with an intermediate range of things which, give or take an order of magnitude or three, are person-sized as well as person useful. It is - therefore? - undoubtedly one of the less glamorous of the

  6. Structural materials assessment

    International Nuclear Information System (INIS)

    The selection of first wall and structural materials is strongly dependent on the proposed design of breeding blanket components and the targets for a fusion reactor development. An envelope of parameters which have to be covered in future R and D activities and which have been adapted in different proposals has been compiled. A short description of interesting material groups like ferritic-martensitic steels, vanadium alloys and ceramic composites, major criteria for their selection and a survey on existing irradiation data is given. This is followed by a comparative assessment of relevant properties and an identification of major issues for each material group. A more detailed proposal for the future R and D activities is then developed for the ferritic-martensitic steels, the present reference material for the European Breeding Blankets. It describes different phases of development necessary for the qualification of this material for DEMO and gives time schedules which are compatible with parallel component developments. A more selective strategy is proposed for the development of vanadium alloys and the ceramic composite material SiC/SiC. For these alternatives work should be concentrated on identified high-risk issues, before a comprehensive development programme is started. The necessity of efficient irradiation facilities to study the irradiation behaviour of the materials under simulation - and realistic fusion conditions is discussed. The availability of high flux fission reactors and necessary extensions of irradiation rigs for the next decade is stressed. Finally it is shown that for the qualification of materials under realistic fusion conditions a high-energetic, high-flux neutron source is mandatory. An accelerator-driven d-Li neutron source (IFMIF) can fulfil essential users requirements as test bed for materials and can technically be made available in due time. In combination with ITER and DEMO, where a concept verification and full scale

  7. BUILDING MATERIALS RECLAMATION PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    David C. Weggel; Shen-En Chen; Helene Hilger; Fabien Besnard; Tara Cavalline; Brett Tempest; Adam Alvey; Madeleine Grimmer; Rebecca Turner

    2010-08-31

    This report describes work conducted on the Building Materials Reclamation Program for the period of September 2008 to August 2010. The goals of the project included selecting materials from the local construction and demolition (C&D) waste stream and developing economically viable reprocessing, reuse or recycling schemes to divert them from landfill storage. Educational resources as well as conceptual designs and engineering feasibility demonstrations were provided for various aspects of the work. The project was divided into two distinct phases: Research and Engineering Feasibility and Dissemination. In the Research Phase, a literature review was initiated and data collection commenced, an advisory panel was organized, and research was conducted to evaluate high volume C&D materials for nontraditional use; five materials were selected for more detailed investigations. In the Engineering Feasibility and Dissemination Phase, a conceptual study for a regional (Mecklenburg and surrounding counties) collection and sorting facility was performed, an engineering feasibility project to demonstrate the viability of recycling or reuse schemes was created, the literature review was extended and completed, and pedagogical materials were developed. Over the two-year duration of the project, all of the tasks and subtasks outlined in the original project proposal have been completed. The Final Progress Report, which briefly describes actual project accomplishments versus the tasks/subtasks of the original project proposal, is included in Appendix A of this report. This report describes the scientific/technical aspects (hypotheses, research/testing, and findings) of six subprojects that investigated five common C&D materials. Table 1 summarizes the six subprojects, including the C&D material studied and the graduate student and the faculty advisor on each subproject.

  8. Building Materials Reclamation Program

    International Nuclear Information System (INIS)

    This report describes work conducted on the Building Materials Reclamation Program for the period of September 2008 to August 2010. The goals of the project included selecting materials from the local construction and demolition (C and D) waste stream and developing economically viable reprocessing, reuse or recycling schemes to divert them from landfill storage. Educational resources as well as conceptual designs and engineering feasibility demonstrations were provided for various aspects of the work. The project was divided into two distinct phases: Research and Engineering Feasibility and Dissemination. In the Research Phase, a literature review was initiated and data collection commenced, an advisory panel was organized, and research was conducted to evaluate high volume C and D materials for nontraditional use; five materials were selected for more detailed investigations. In the Engineering Feasibility and Dissemination Phase, a conceptual study for a regional (Mecklenburg and surrounding counties) collection and sorting facility was performed, an engineering feasibility project to demonstrate the viability of recycling or reuse schemes was created, the literature review was extended and completed, and pedagogical materials were developed. Over the two-year duration of the project, all of the tasks and subtasks outlined in the original project proposal have been completed. The Final Progress Report, which briefly describes actual project accomplishments versus the tasks/subtasks of the original project proposal, is included in Appendix A of this report. This report describes the scientific/technical aspects (hypotheses, research/testing, and findings) of six subprojects that investigated five common C and D materials. Table 1 summarizes the six subprojects, including the C and D material studied and the graduate student and the faculty advisor on each subproject.

  9. [Elastomeric impression materials].

    Science.gov (United States)

    Levartovsky, S; Folkman, M; Alter, E; Pilo, R

    2011-04-01

    Elastomeric impression materials are in common use. The impression taken should be highly precise, thus, requiring specific care when manipulatingthese materials. There are 4 groups of elastomers; polysulfide, condensation silicone, addition silicone and polyether; each differ in their setting mechanism and their physical and chemical properties. This review elaborates the major properties of elastomers and its implications on their use. The impression material is inserted into the patient's mouth in a viscous state and transforms into viscoelastic state, upon withdrawal, influencing the residual deformation. The requirements are minimal residual deformation or maximal elastic recovery. As the mouth is a wet environment a major consideration is hydrophilicity. The wettability which is estimated by measuring either the contact angle of a droplet of water and the substrate post setting or the contact angle of a droplet of impression material and the wet tooth pre setting, determines the interaction of the material with both mouth fluids and gypsum. As the primary end target is to obtain a model depicting accurately the oral details, an attention to the impressions' compatibility with gypsum should also be given. Many studies were conducted to get a thorough understanding of the hydrophilic properties of each material, and the mechanism utilized, such as surfactants in hydrophilic PVS. Polyether is the only material that is truly hydrophilic; it exhibits the lowest contact angle, during and after setting. Recent studies show that during setting the Polyether hydrophilicity is increased compared to the condition after setting. Dimensional stability, a crucial property of the impression, is affected by the physical and chemical attributes of the material, such as its tear strength. Polysulfide has the highest tear strength. Tear Strength is affected by two major parameters, viscosity, a built-in property, and how fast the impression is pulled out of the mouth, the

  10. A Material Conferring Hemocompatibility.

    Science.gov (United States)

    Everett, William; Scurr, David J; Rammou, Anna; Darbyshire, Arnold; Hamilton, George; de Mel, Achala

    2016-01-01

    There is a need for biomimetic materials for use in blood-contacting devices. Blood contacting surfaces maintain their patency through physico-chemical properties of a functional endothelium. A poly(carbonate-urea) urethane (PCU) is used as a base material to examine the feasibility of L-Arginine methyl ester (L-AME) functionalized material for use in implants and coatings. The study hypothesizes that L-AME, incorporated into PCU, functions as a bioactive porogen, releasing upon contact with blood to interact with endothelial nitric oxide synthase (eNOS) present in blood. Endothelial progenitor cells (EPC) were successfully cultured on L-AME functionalized material, indicating that L-AME -increases cell viability. L-AME functionalized material potentially has broad applications in blood-contacting medical devices, as well as various other applications requiring endogenous up-regulation of nitric oxide, such as wound healing. This study presents an in-vitro investigation to demonstrate the novel anti-thrombogenic properties of L-AME, when in solution and when present within a polyurethane-based polymer. PMID:27264087

  11. Materials Science Programs

    International Nuclear Information System (INIS)

    The Division of Materials Sciences is located within the Department of Energy in the Office of Basic Energy Sciences. The Office of Basic Energy Sciences reports to the Director of the Office of Energy Research. The Director of this office is appointed by the President with Senate consent. The Director advises the Secretary on the physical research program; monitors the Department's R ampersand D programs; advises the Secretary on management of the laboratories under the jurisdiction of the Department, excluding those that constitute part of the nuclear weapon complex; and advises the Secretary on basic and applied research activities of the Department. The research covers a spectrum of scientific and engineering areas of interest to the Department of Energy and is conducted generally by personnel trained in the disciplines of Solid State Physics, Metallurgy, Ceramics, Chemistry, Polymers and Materials Science. The Materials Sciences Division supports basic research on materials properties and phenomena important to all energy systems. The aim is to provide the necessary base of materials knowledge required to advance the nation's energy programs. This report contains a listing of research underway in FY 1989 together with a convenient index to the Division's programs

  12. Panel 3 - material science

    Energy Technology Data Exchange (ETDEWEB)

    Sarrao, John L [Los Alamos National Laboratory; Yip, Sidney [MIT

    2010-01-01

    In the last decades, NNSA's national security challenge has evolved, and the role of simulation and computation has grown dramatically. The process of certifying nuclear weapons performance has changed from one based on integrated tests to science-based certification in which underground nuclear tests have been replaced by large-scale simulations, appropriately validated with fundamental experimental data. Further, the breadth of national security challenges has expanded beyond stewardship of a nuclear deterrent to a broad range of global and asymmetric threats. Materials challenges are central to the full suite of these national security challenges. Mission requirements demand that materials perform predictably in extreme environments -- high pressure, high strain rate, and hostile irradiation and chemical conditions. Considerable advances have been made in incorporating fundamental materials physics into integrated codes used for component certification. On the other hand, significant uncertainties still remain, and materials properties, especially at the mesoscale, are key to understanding uncertainties that remain in integrated weapons performance codes and that at present are treated as empirical knobs. Further, additional national security mission challenges could be addressed more robustly with new and higher performing materials.

  13. Radioactive material storage vessel

    International Nuclear Information System (INIS)

    In a radioactive material storage vessel having a single sealing boundary in the cylindrical portion and a double sealing boundary in the lid portion, and the outer circumference of the vessel being cooled by air, in which difference is made between the pressure in a radioactive material storage chamber and the pressure in an intermediate chamber present between a primary sealing lid and a secondary sealing lid. A valve is disposed to the primary sealing lid, which breaks the sealing between the radioactive material containing chamber and the intermediate chamber when the difference between the pressure of the containing chamber and that of the intermediate chamber is reduced to lower than a predetermined value, and a sensor for detecting pressure change in the intermediate chamber is disposed to the secondary sealing lid. In addition, a shrinkable member having at least a predetermined length and an extensible length is disposed to the primary sealing lid, and a displacement sensor capable of detecting the change of the length of the shrinkable member is disposed to the secondary sealing lid. Then, when the sealing boundary at the cylinder portion of the radioactive material containing chamber should be broken in the radioactive material storage vessel, it can be detected. (N.H.)

  14. Neutron shielding material

    International Nuclear Information System (INIS)

    From among the neutron shielding materials of the 'kobesh' series developed by Kobe Steel, Ltd. for transport and storage packagings, silicon rubber base type material has been tested for several items with a view to practical application and official authorization, and in order to determine its adaptability to actual vessels. Silicon rubber base type 'kobesh SR-T01' is a material in which, from among the silicone rubber based neutron shielding materials, the hydrogen content is highest and the boron content is most optimized. Its neutron shielding capability has been already described in the previous report (Taniuchi, 1986). The following tests were carried out to determine suitability for practical application; 1) Long-term thermal stability test 2) Pouring test on an actual-scale model 3) Fire test The experimental results showed that the silicone rubber based neutron shielding material has good neutron shielding capability and high long-term fire resistance, and that it can be applied to the advanced transport packaging. (author)

  15. Materials with high magnetostriction

    International Nuclear Information System (INIS)

    The magnetostrictive properties of cubic Laves phases such as TbFe2, Terfenol D and SmFe2 are summarised. It is shown that SmFe2 can be an interesting candidate as a high magnetostrictive material even in the as cast ''dirty'' state. Fe-X alloys based on Fe-Ga but also Fe-Al are presented as materials with a medium magnetostriction, however with the big advantage of a magnetically soft material. Generally all nonmagnetic substutional elements which cause an increase of the interatomic distance in the Fe-lattice (such as Ga, Al, Si) cause an increase of the magnetostriction too. In Ni-Ga a reduction of the magnetostriction was found. Another interesting material with high magnetostriction is CoFe2O4 which is cheap, easy to produce and an oxidic material. Here magnetostriction values up to 400 ppm can be achieved by hydrostatic compaction followed by a field annealing

  16. Hydrazine Materials Compatibility Database

    Science.gov (United States)

    Schmidt, E. W.

    2004-10-01

    Anhydrous hydrazine and its methyl derivatives MMH and UDMH have been safely used as monopropellants and bipropellant fuels in thousands of satellites and space probes, hundreds of expendable launch vehicles and hundreds of piloted reusable launch vehicle flights. The term hydrazine(s) is used here to describe the three propellant hydrazines and their mixtures. Over the years, a significant amount of experience has accumulated in the selection of compatible materials of construction for these and other rocket propellants. Only a few materials incompatibility issues have arisen in the recent past. New materials of construction have become available during the past decades which have not yet been extensively tested for long-term compatibility with hydrazine(s). These new materials promise lightweight (i. e., lighter weight) propulsion system designs and increased payloads in launch vehicles and satellites. Other new materials offer reduced contamination caused by leached ingredients, e. g. less silica leaching from diaphragms in propellant management devices in propellant tanks. This translates into longer mission life.

  17. EDITORIAL: Electroactive polymer materials

    Science.gov (United States)

    Bar-Cohen, Yoseph; Kim, Kwang J.; Ryeol Choi, Hyouk; Madden, John D. W.

    2007-04-01

    Imitating nature's mechanisms offers enormous potential for the improvement of our lives and the tools we use. This field of the study and imitation of, and inspiration from, nature's methods, designs and processes is known as biomimetics. Artificial muscles, i.e. electroactive polymers (EAPs), are one of the emerging technologies enabling biomimetics. Polymers that can be stimulated to change shape or size have been known for many years. The activation mechanisms of such polymers include electrical, chemical, pneumatic, optical and magnetic. Electrical excitation is one of the most attractive stimulators able to produce elastic deformation in polymers. The convenience and practicality of electrical stimulation and the continual improvement in capabilities make EAP materials some of the most attractive among activatable polymers (Bar-Cohen Y (ed) 2004 Electroactive Polymer (EAP) Actuators as Artificial Muscles—Reality, Potential and Challenges 2nd edn, vol PM136 (Bellingham, WA: SPIE Press) pp 1-765). As polymers, EAP materials offer many appealing characteristics that include low weight, fracture tolerance and pliability. Furthermore, they can be configured into almost any conceivable shape and their properties can be tailored to suit a broad range of requirements. These capabilities and the significant change of shape or size under electrical stimulation while being able to endure many cycles of actuation are inspiring many potential possibilities for EAP materials among engineers and scientists in many different disciplines. Practitioners in biomimetics are particularly excited about these materials since they can be used to mimic the movements of animals and insects. Potentially, mechanisms actuated by EAPs will enable engineers to create devices previously imaginable only in science fiction. For many years EAP materials received relatively little attention due to their poor actuation capability and the small number of available materials. In the last fifteen

  18. Nanoscale Ionic Materials

    KAUST Repository

    Rodriguez, Robert

    2008-11-18

    Polymer nanocomposites (nanoparticles dispersed in a polymer matrix) have been the subject of intense research for almost two decades in both academic and industrial settings. This interest has been fueled by the ability of nanocomposites to not only improve the performance of polymers, but also by their ability to introduce new properties. Yet, there are still challenges that polymer nanocomposites must overcome to reach their full potential. In this Research News article we discuss a new class of hybrids termed nanoparticle ionic materials (NIMS). NIMS are organic-inorganic hybrid materials comprising a nanoparticle core functionalized with a covalently tethered ionic corona. They are facilely engineered to display flow properties that span the range from glassy solids to free flowing liquids. These new systems have unique properties that can overcome some of the challenges facing nanocomosite materials. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

  19. Material and Virtuality

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    world and a physical world can interchange. The paper suggest an approach where an overlapping of virtuality and the tangible material output from digital fabrication machines create a method of using materialisation tools as instruments to connect the reality of materials and to an exploring process......Through tangible experiments this paper discusses the dialogues between digital architectural drawing and the process of materialisation. The paper sets op the spans between virtual and actual and control and uncertainty making these oppositions a combined spaces where information between a digital...... established through these experiments is both tangible and directly connected to real actions in digital drawing or material processing but also the base for theoretical contemplations of the relation between virtual and actual and control and uncertainty....

  20. Nuclear material accounting handbook

    International Nuclear Information System (INIS)

    The handbook documents existing best practices and methods used to account for nuclear material and to prepare the required nuclear material accounting reports for submission to the IAEA. It provides a description of the processes and steps necessary for the establishment, implementation and maintenance of nuclear material accounting and control at the material balance area, facility and State levels, and defines the relevant terms. This handbook serves the needs of State personnel at various levels, including State authorities, facility operators and participants in training programmes. It can assist in developing and maintaining accounting systems which will support a State's ability to account for its nuclear material such that the IAEA can verify State declarations, and at the same time support the State's ability to ensure its nuclear security. In addition, the handbook is useful for IAEA staff, who is closely involved with nuclear material accounting. The handbook includes the steps and procedures a State needs to set up and maintain to provide assurance that it can account for its nuclear material and submit the prescribed nuclear material accounting reports defined in Section 1 and described in Sections 3 and 4 in terms of the relevant agreement(s), thereby enabling the IAEA to discharge its verification function as defined in Section 1 and described in Sections 3 and 4. The contents of the handbook are based on the model safeguards agreement and, where applicable, there will also be reference to the model additional protocol. As a State using The handbook consists of five sections. In Section 1, definitions or descriptions of terms used are provided in relation to where the IAEA applies safeguards or, for that matter, accounting for and control of nuclear material in a State. The IAEA's approach in applying safeguards in a State is also defined and briefly described, with special emphasis on verification. In Section 2, the obligations of the State

  1. Micromechanics of Composite Materials

    CERN Document Server

    Dvorak, George

    2013-01-01

    This book presents a broad exposition of analytical and numerical methods for modeling composite materials, laminates, polycrystals and other heterogeneous solids, with emphasis on connections between material properties and responses on several length scales, ranging from the nano and microscales to the macroscale. Many new results and methods developed by the author are incorporated into a rich fabric of the subject, which has been explored by several researchers over the last 40 years.   The first  part of the book reviews anisotropic elasticity theory, and then it describes the frequently used procedures and theorems for bounding and estimating overall properties, local fields and energy changes in elastic inhomogeneities, heterogeneous media, fiber composites and functionally graded materials.  Those are caused by mechanical loads and by phase eigenstrains, such as thermal, transformation and inelastic strains, and also by cavities and cracks.    Worked examples show that the eigendeformations may...

  2. Optimized nanoporous materials.

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Paul V. (University of Illinois at Urbana-Champaign, Urbana, IL); Langham, Mary Elizabeth; Jacobs, Benjamin W.; Ong, Markus D.; Narayan, Roger J. (North Carolina State University, Raleigh, NC); Pierson, Bonnie E. (North Carolina State University, Raleigh, NC); Gittard, Shaun D. (North Carolina State University, Raleigh, NC); Robinson, David B.; Ham, Sung-Kyoung (Korea Basic Science Institute, Gangneung, South Korea); Chae, Weon-Sik (Korea Basic Science Institute, Gangneung, South Korea); Gough, Dara V. (University of Illinois at Urbana-Champaign, Urbana, IL); Wu, Chung-An Max; Ha, Cindy M.; Tran, Kim L.

    2009-09-01

    Nanoporous materials have maximum practical surface areas for electrical charge storage; every point in an electrode is within a few atoms of an interface at which charge can be stored. Metal-electrolyte interfaces make best use of surface area in porous materials. However, ion transport through long, narrow pores is slow. We seek to understand and optimize the tradeoff between capacity and transport. Modeling and measurements of nanoporous gold electrodes has allowed us to determine design principles, including the fact that these materials can deplete salt from the electrolyte, increasing resistance. We have developed fabrication techniques to demonstrate architectures inspired by these principles that may overcome identified obstacles. A key concept is that electrodes should be as close together as possible; this is likely to involve an interpenetrating pore structure. However, this may prove extremely challenging to fabricate at the finest scales; a hierarchically porous structure can be a worthy compromise.

  3. Strong, Lightweight, Porous Materials

    Science.gov (United States)

    Leventis, Nicholas; Meador, Mary Ann B.; Johnston, James C.; Fabrizio, Eve F.; Ilhan, Ulvi

    2007-01-01

    A new class of strong, lightweight, porous materials has been invented as an outgrowth of an effort to develop reinforced silica aerogels. The new material, called X-Aerogel is less hygroscopic, but no less porous and of similar density to the corresponding unmodified aerogels. However, the property that sets X-Aerogels apart is their mechanical strength, which can be as much as two and a half orders of magnitude stronger that the unmodified aerogels. X-Aerogels are envisioned to be useful for making extremely lightweight, thermally insulating, structural components, but they may also have applications as electrical insulators, components of laminates, catalyst supports, templates for electrode materials, fuel-cell components, and filter membranes.

  4. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  5. Hysteresis in Magnetocaloric Materials

    DEFF Research Database (Denmark)

    von Moos, Lars

    characterization of the magnetocaloric effect (MCE) in these materials is done through conventional indirect magnetometric and calorimetric methods, as well as newly developed direct methods. The determination of the MCE due to a magnetic field change is in principle given by the isofield material entropy curves...... the low field heating and high field cooling entropy curves, which can reduce the MCE estimate significantly. The experimental data obtained through the material characterization is used as a foundation for Preisach type models. This type of model is suited to handle the non-equilibrium nature of first...... set points, which is demonstrated to induce partial hysteresis loop behavior that will generally underestimate thermal hysteresis. Furthermore it is shown that care should be taken in non-isofield type experiments, as is the case for direct MCE experiments. Measuring the temperature dependence...

  6. Optimized manufacturable porous materials

    DEFF Research Database (Denmark)

    Andreassen, Erik; Andreasen, Casper Schousboe; Jensen, Jakob Søndergaard;

    to include manufacturing constraints in the optimization. This work focuses on incorporating the manufacturability into the optimization procedure, allowing the resulting material structure to be manufactured directly using rapid manufacturing techniques, such as selective laser melting....../sintering (SLM/S). The available manufacturing methods are best suited for porous materials (one constituent and void), but the optimization procedure can easily include more constituents. The elasticity tensor is found from one unit cell using the homogenization method together with a standard finite element...... (FE) discretization. The distribution of the material in the unit cell is optimized according to a given objective (e.g. maximum bulk modulus or minimum Poisson’s ratio) and some given constraints (e.g. isotropy) using topology optimization. The manufacturability is achieved using various filtering...

  7. Fire Resistant Materials

    Science.gov (United States)

    1982-01-01

    Fire hazard is greater in atmospheres containing a high percentage of oxygen under pressure. NASA intensified its fire safety research after a 1967 Apollo fire. A chemically treated fabric called Durette developed by Monsanto Company, which will not burn or produce noxious fumes, was selected as a material for Apollo astronaut garments. Monsanto sold production rights for this material to Fire Safe Products (FSP). Durette is now used for a wide range of applications such as: sheets, attendants' uniforms in hyperbaric chambers; crew's clothing, furniture and interior walls of diving chambers operated by the U.S. Navy and other oceanographic companies and research organizations. Pyrotect Safety Equipment, Minneapolis, MN produces Durette suits for auto racers, refuelers and crew chiefs from material supplied by FSP. FSP also manufactures Durette bags for filtering gases and dust from boilers, electric generators and similar systems. Durette bags are an alternative to other felted fiber capable of operating at high temperature that cost twice as much.

  8. Radioactive material storage

    International Nuclear Information System (INIS)

    Purpose: To make a spent fuel accommodating box movable and accommodate spent fuels at a position farther than the side wall of the storage installation and to draw the spent fuel near to the side wall with the lapse of the storage time, thereby attenuating the radiation effectively and increasing the storage capacity. Constitution: A space (box) accommodating radioactive materials is made movable, and the radiation is effectively shielded by the attenuation of the radioactive materials in storage due to the lapse of the storage time and the shielding of the radiation due to the liquefied shielding material up to the shielding wall of the storage installation, whereby the shielding wall of the storage installation is made thin and the capacity in the installation is enlarged, thus the accommodation capacity, that is, the storage capacity being increased. (Yoshihara, H.)

  9. Radioactive materials transport

    International Nuclear Information System (INIS)

    Growing public concern over the potential hazards of transporting radioactive materials has led to a considerable body of state and local restrictions, including bans in certain jurisdictions. In spite of a good safety record and the acknowledged necessity of many of these shipments, restrictive enactments continue to proliferate. Users of radioactive materials contend that these restrictions impede shipments and contribute to rising costs while, on the other hand, state and local officials are concerned with the health and safety of their citizenry. A showdown between state and local safety interests and federal promoters of unencumbered interstate commerce will occur when the proposed US Department of Transportation (DOT) highway routing rules for the shipment of radioactive materials are implemented February 1, 1982. As proposed, these rules would preempt several restrictive state and local requirements

  10. Synthesis of superhard materials

    Directory of Open Access Journals (Sweden)

    Vladimir L. Solozhenko

    2005-11-01

    Full Text Available The study of solids at high pressures and temperatures is an important area of modern condensed matter physics, chemistry, and materials science. The last decade has seen revolutionary developments in the field of high-pressure experimentation: new types of cells allow a wider range of experiments at higher pressures, and third-generation synchrotrons have brought the possibility of conducting X-ray diffraction experiments that were unthinkable only 10 years ago. In this review, we give some recent examples to illustrate how modern high-pressure tools, such as the diamond anvil cell (DAC, multianvil press, and shock compression, can be used to answer questions relevant to the synthesis of new advanced materials. Our examples will be related mostly to superhard materials.

  11. Polymers from renewable materials.

    Science.gov (United States)

    Rus, Anika Zafiah M

    2010-01-01

    With the world facing depletion of its oil reserves, attention is being focused on how the plastics industry will address shortages and price increases in its crucial raw materials. One renewable resource is that of vegetable oils and fats and about a dozen crop plants make up the main vegetable oil-seed market. The main constituents of these oils are saturated and unsaturated fatty acids that are unique to the plant in which they have been developed. Moreover, technological processes can produce more well-defined and pure oils, and the fatty acid contents in the vegetable oils can be altered with modern crop development techniques. This article describes recent advances in utilising such vegetable oils in sourcing new polymeric materials. It also gives the context for the development of polymers based on renewable materials in general. PMID:21047019

  12. Applied bioactive polymeric materials

    CERN Document Server

    Carraher, Charles; Foster, Van

    1988-01-01

    The biological and biomedical applications of polymeric materials have increased greatly in the past few years. This book will detail some, but not all, of these recent developments. There would not be enough space in this book to cover, even lightly, all of the major advances that have occurred. Some earlier books and summaries are available by two of this book's Editors (Gebelein & Carraher) and these should be consul ted for additional information. The books are: "Bioactive Polymeric Systems" (Plenum, 1985); "Polymeric Materials In Medication" (Plenum, 1985); "Biological Acti vi ties of Polymers" (American Chemical Society, 1982). Of these three, "Bioacti ve Polymeric Systems" should be the most useful to a person who is new to this field because it only contains review articles written at an introductory level. The present book primarily consists of recent research results and applications, with only a few review or summary articles. Bioactive polymeric materials have existed from the creation of life...

  13. Materials for nuclear reactors

    International Nuclear Information System (INIS)

    The improved performance of present generation nuclear reactors and the realization of advanced reactor concepts, both, require development of better materials. Physical metallurgy/materials science principles which have been exploited in meeting the exacting requirements of nuclear reactor materials (fuels and structural materials), are outlined citing a few specific examples. While the incentive for improvement of traditional fuels (e.g., UO2 fuel) is primarily for increasing the average core burn up, the development of advanced fuels (e.g., MOX, mixed carbide, nitride, silicide and dispersion fuels) are directed towards better utilization of fissile and fertile inventories through adaptation of innovative fuel cycles. As the burn up of UO2 fuel reaches higher levels, a more detailed and quantitative understanding of the phenomena such as fission gas release, fuel restructuring induced by radiation and thermal gradients and pellet-clad interaction is being achieved. Development of zirconium based alloys for both cladding and pressure tube applications is discussed with reference to their physical metallurgy, fabrication techniques and in-reactor degradation mechanisms. The issue of radiation embrittlement of reactor pressure vessels (RPVs) is covered drawing a comparison between the western and eastern specifications of RPV steels. The search for new materials which can stand higher rates of atomic displacement due to radiation has led to the development of swelling resistant austenitic and ferritic stainless steels for fast reactor applications as exemplified by the development of the D-9 steel for Indian fast breeder reactor. The presentation will conclude by listing various materials related phenomena, which have a strong bearing on the successful development of future nuclear energy systems. (author)

  14. Terahertz Sensing of Materials

    Science.gov (United States)

    Xuan, G.; Ghosh, S.; Kim, S.; Lv, P.-C.; Buma, T.; Weng, B.; Barner, K.; Kolodzey, J.

    2007-06-01

    Biomolecules such as DNA and proteins exhibit a wealth of modes in the Terahertz (THz) range from the rotational, vibrational and stretching modes of biomolecules. Many materials such as drywall that are opaque to human eyes are transparent to THz. Therefore, it can be used as a powerful tool for biomolecular sensing, biomedical analysis and through-the-wall imaging. Experiments were carried out to study the absorption of various materials including DNA and see-through imaging of drywall using FTIR spectrometer and Time Domain Spectroscopy (TDS) system.

  15. Materials for hydrogen storage

    Directory of Open Access Journals (Sweden)

    Andreas Züttel

    2003-09-01

    The goal is to pack hydrogen as close as possible, i.e. to reach the highest volumetric density by using as little additional material as possible. Hydrogen storage implies the reduction of an enormous volume of hydrogen gas. At ambient temperature and atmospheric pressure, 1 kg of the gas has a volume of 11 m3. To increase hydrogen density, work must either be applied to compress the gas, the temperature decreased below the critical temperature, or the repulsion reduced by the interaction of hydrogen with another material.

  16. Materials separation by dielectrophoresis

    Science.gov (United States)

    Sagar, A. D.; Rose, R. M.

    1988-01-01

    The feasibility of vacuum dielectrophoresis as a method for particulate materials separation in a microgravity environment was investigated. Particle separations were performed in a specially constructed miniature drop-tower with a residence time of about 0.3 sec. Particle motion in such a system is independent of size and based only on density and dielectric constant, for a given electric field. The observed separations and deflections exceeded the theoretical predictions, probably due to multiparticle effects. In any case, this approach should work well in microgravity for many classes of materials, with relatively simple apparatus and low weight and power requirements.

  17. The materiality of Code

    DEFF Research Database (Denmark)

    Soon, Winnie

    2014-01-01

    , Twitter and Facebook). The focus is not to investigate the functionalities and efficiencies of the code, but to study and interpret the program level of code in order to trace the use of various technological methods such as third-party libraries and platforms’ interfaces. These are important to...... understand the socio-technical side of a changing network environment. Through the study of code, including but not limited to source code, technical specifications and other materials in relation to the artwork production, I would like to explore the materiality of code that goes beyond technical...

  18. The Materiality of Learning

    DEFF Research Database (Denmark)

    Sørensen, Estrid

    . Drawing on science and technology studies (STS), Estrid Sørensen compares an Internet-based 3D virtual environment project in a fourth-grade class with the class's work with traditional learning materials, including blackboards, textbooks, notebooks, pencils, and rulers. Taking into account pupils' and...... postgraduate students interested in a variety of fields, including educational studies, educational psychology, social anthropology, and STS. Original ethnographic descriptions showing the fine details of how materials influence the learning process Introduces the advanced and complex Actor-Network Theory to...

  19. Ultrasonic Processing of Materials

    Energy Technology Data Exchange (ETDEWEB)

    Meek, Thomas T.; Han, Qingyou; Jian, Xiaogang; Xu, Hanbing

    2005-06-30

    The purpose of this project was to determine the impact of a new breakthrough technology, ultrasonic processing, on various industries, including steel, aluminum, metal casting, and forging. The specific goals of the project were to evaluate core principles and establish quantitative bases for the ultrasonc processing of materials, and to demonstrate key applications in the areas of grain refinement of alloys during solidification and degassing of alloy melts. This study focussed on two classes of materials - aluminum alloys and steels - and demonstrated the application of ultrasonic processing during ingot casting.

  20. Materials development for SOEC

    International Nuclear Information System (INIS)

    The full paper being unavailable at the time of publication, only the abstract is included: Emphasis on energy security issues has brought much-needed attention to economic production of hydrogen as the secondary energy carrier for non-electrical markets as well as to meet increasing demand for crude upgrading and desulphurization. While steam reforming of methane is the current method of production of hydrogen, the fossil fuel feed consumes non-renewable fuel while emitting greenhouse gases. Thus, in the long run, efficient, environmentally-friendly and economic means of hydrogen production using nuclear and renewable energy needs to be developed. Steam electrolysis, particularly using high temperature ceramic membrane processes, provides an attractive option for efficient generation of high purity hydrogen. The high operating temperature that is necessary for an efficient electrolysis process requires the use of materials that are stable at those temperatures. The materials and fabrication technology that are used for high temperature solid oxide fuel cells (SOFC) are directly applicable to high temperature solid oxide electrolysis cells (SOEC). Thus, much of the research work done in the SOFC area is directly applicable to SOEC technology. Not only the materials set but also the cell and multi-cell stack designs of SOEC have followed the technology advances of SOFC development. Ceramatec, in collaboration with Idaho National Laboratory and under the DOE Nuclear Hydrogen Initiative has tested SOEC cells and stacks of various hydrogen production rates up to 5000 NL/hr using SOFC materials set developed at Ceramatec. While the initial stack performance is adequate, long-term performance stability is not at an acceptable level for commercial hydrogen production. Several potential causes for degradation were identified; some are common to SOFC device operation while others are unique to SOEC mode of operation. These range from phase instability of materials resulting

  1. Materials for sustainable energy

    CERN Document Server

    Dusastre, Vincent

    2010-01-01

    The search for cleaner, cheaper, smaller and more efficient energy technologies has to a large extent been motivated by the development of new materials. The aim of this collection of articles is therefore to focus on what materials-based solutions can offer and show how the rationale design and improvement of their physical and chemical properties can lead to energy-production alternatives that have the potential to compete with existing technologies. In terms of alternative means to generate electricity that utilize renewable energy sources, the most dramatic breakthroughs for both mobile (i

  2. Adhesive dental materials

    International Nuclear Information System (INIS)

    Two main classes of material are involved, the glass-ionomer cements and the composite resins. This investigation describes the way they are bonded to the tooth and highlights their differences. Glass ionomers develop a zone of interaction with the tooth as they age which ultimately gives an extremely strong bond, and results in excellent retention rates. By contrast, bonding of composite resins is more complicated and possibly less effective, though these materials have better wear resistance and better aesthetics than glass ionomers. Assessment of bond durability is difficult. This is because a dental restorative can fail by a number of mechanisms apart from de bonding: for example, through wear or fracture

  3. Magnetic refrigeration materials

    Institute of Scientific and Technical Information of China (English)

    戴闻; 沈保根; 高政祥

    2001-01-01

    Magnetic refrigeration has drawn much attention because of its greater efficiency and higher reliability than the traditional gas-cycle refrigeration technology. Recently, a kind of new materials with a giant magnetocaloric effect in the subroom temperature range, Gd5 (Six Ge1- x)4, was discovered, which boosts the search for high-performance magnetic refrigerants. However, the intermetallic compounds Gd5 (SixGe1 - x )4 belong to the first order transition materials; their performance in practical magnetic refrigeration cycles remains controversial. In this paper the developing tendency of the refrigerants are discussed on the basis of our work.

  4. Materiality, Practice and Body

    DEFF Research Database (Denmark)

    Johansen, Stine Liv; Skovbjerg-Karoff, Helle

    2009-01-01

    In order to understand the interaction between human and technology, the relationship must be emphasized as a triangulation between materiality, body and practice. By introducing play situations from a just finished empirical study in three bigger cities in Denmark, this paper will address the...... interplay from the human‟s point of view, as a body doing a certain practice, which is constantly produced by taking approaches which comes from phenomenology and practice theory. We introduce aspects of play understood as a dynamic between materiality, body and practice with the goal of inspiring not only...

  5. Reactor pressure vessel materials

    International Nuclear Information System (INIS)

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. Chapter 3 offers a detailed treatment of the selection criteria and properties of reactor pressure vessel materials. The main attention is directed towards steel and ingot making and the subsequent material processing

  6. Gravitation in material media

    International Nuclear Information System (INIS)

    When two gravitating bodies reside in a material medium, Newton's law of universal gravitation must be modified to account for the presence of the medium. A modified expression of Newton's law is known in the literature, but lacks a clear connection with existing gravitational theory. Newton's law in the presence of a homogeneous material medium is herein derived on the basis of classical, Newtonian gravitational theory and by a general relativistic use of Archimedes' principle. It is envisioned that the techniques presented herein will be most useful to graduate students and those undergraduate students having prior experience with vector analysis and potential theory.

  7. Interactions of tritium and materials

    Energy Technology Data Exchange (ETDEWEB)

    Yamawaki, Michio; Yamaguchi, Kenji; Tanaka, Satoru; Ono, Futaba (Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.); Yamamoto, Takuya

    1993-11-01

    In D-T burning fusion reactors, problems related to tritium-material interactions are vitally important. From this point of view, plasma-material interactions, blanket breeder material-tritium interactions, safety aspects of tritium-material interactions and tritium storage materials are reviewed with emphasis on the works going on in the authors' laboratories. (author) 83 refs.

  8. Aerogel/polymer composite materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2010-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  9. Composite materials having thiol groups

    International Nuclear Information System (INIS)

    A composite material having thiol groups comprises a rigid support material. The composite material may comprise a deformable gel (eg agarose) having thiol groups retained within the pore structure of a porous rigid support material (e.g. Kieselghur). The particles of composite material are used to prepare a radioactive gold isotope from a mercury 'parent' isotope. (author)

  10. Supercapacitors specialities - Materials review

    International Nuclear Information System (INIS)

    The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

  11. Supercapacitors specialities - Materials review

    Energy Technology Data Exchange (ETDEWEB)

    Obreja, Vasile V. N. [National Research and Development Institute for Microtechnologies (IMT-Bucuresti), Bucharest, 126A Erou Iancu Nicolae Street, 077190 (Romania)

    2014-06-16

    The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

  12. Supercapacitors specialities - Materials review

    Science.gov (United States)

    Obreja, Vasile V. N.

    2014-06-01

    The electrode material is a key component for supercapacitor cell performance. As it is known, performance comparison of commercial available batteries and supercapacitors reveals significantly lower energy storage capability for supercapacitor devices. The energy density of commercial supercapacitor cells is limited to 10 Wh/kg whereas that of common lead acid batteries reaches 35-40 Wh/kg. For lithium ion batteries a value higher than 100 Wh/kg is easily available. Nevertheless, supercapacitors also known as ultracapacitors or electrochemical capacitors have other advantages in comparison with batteries. As a consequence, many efforts have been made in the last years to increase the storage energy density of electrochemical capacitors. A lot of results from published work (research and review papers, patents and reports) are available at this time. The purpose of this review is a presentation of the progress to date for the use of new materials and approaches for supercapacitor electrodes, with focus on the energy storage capability for practical applications. Many reported results refer to nanostructured carbon based materials and the related composites, used for the manufacture of experimental electrodes. A specific capacitance and a specific energy are seldom revealed as the main result of the performed investigation. Thus for nanoprous (activated) carbon based electrodes a specific capacitance up to 200-220 F/g is mentioned for organic electrolyte, whereas for aqueous electrolyte, the value is limited to 400-500 F/g. Significant contribution to specific capacitance is possible from fast faradaic reactions at the electrode-electrolyte interface in addition to the electric double layer effect. The corresponding energy density is limited to 30-50 Wh/kg for organic electrolyte and to 12-17 Wh/kg for aqueous electrolyte. However such performance indicators are given only for the carbon material used in electrodes. For a supercapacitor cell, where two electrodes

  13. Kurdish. Materials Status Report.

    Science.gov (United States)

    Center for Applied Linguistics, Washington, DC. Language/Area Reference Center.

    The materials status report for Kurdish is one of a series intended to provide the nonspecialist with a picture of the availability and quality of texts for teaching a given language to English speakers. Each report consists of: (1) a brief narrative description of the language, the areas where it is spoken, its major dialects, its writing system,…

  14. Improvement of turbine materials

    International Nuclear Information System (INIS)

    Materials for turbine blades and rotors are discussed with a view to the following subjects: Long period creep behaviour, gas/metal reactions, fatigue behaviour in long-term and creep strength testing, fracture mechanics testing, creep/fatigue interactions, development of a turbine blade of TZM, jointing of TZM, decontamination. (orig./IHOE)

  15. Reactor Materials Research

    International Nuclear Information System (INIS)

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  16. Rudiments of materials science

    CERN Document Server

    Pillai, SO

    2007-01-01

    Writing a comprehensive book on Materials Science for the benefit of undergraduate courses in Science and Engineering was a day dream of the first author, Dr. S.O. Pillai for a long period. However, the dream became true after a lapse of couple of years. Lucid and logical exposition of the subject matter is the special feature of this book.

  17. Materials Technical Team Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-08-01

    Roadmap identifying the efforts of the Materials Technical Team (MTT) to focus primarily on reducing the mass of structural systems such as the body and chassis in light-duty vehicles (including passenger cars and light trucks) which enables improved vehicle efficiency regardless of the vehicle size or propulsion system employed.

  18. Chemistry and Materials Science

    International Nuclear Information System (INIS)

    Thrust areas of the weapons-supporting research are growth, structure, and reactivity of surfaces and thin films; uranium research; physics and processing of metals; energetic materials; etc. The laboratory-directed R and D include director's initiatives and individual projects, and transactinium institute studies

  19. RECON training materials

    International Nuclear Information System (INIS)

    This collection of materials for use in a DOE/RECON training session includes information about terminal commands, logging on, document availability, search strategy models, and some of the data bases available on DOE/RECON. An evaluation questionnaire is included

  20. Fusion reactor materials

    International Nuclear Information System (INIS)

    At the Belgian Nuclear Research Centre SCK-CEN, activities related to fusion focus on environmental tolerance of opto-electronic components. The objective of this program is to contribute to the knowledge on the behaviour, during and after neutron irradiation, of fusion-reactor materials and components. The main scientific activities for 1997 are summarized

  1. Multiscale Biological Materials

    DEFF Research Database (Denmark)

    Frølich, Simon

    2016-01-01

    cortical bone, and the nanoscale response of bone in compression. Lastly, a framework for the investigation of biological design principles has been developed. The framework combines parametric modeling, multi-material 3D-printing, and direct mechanical testing to efficiently screen large parameter spaces...

  2. Making Biological Materials

    Institute of Scientific and Technical Information of China (English)

    Julian F.V.Vincent

    2005-01-01

    @@ 1 Chemistry and synthesis 1.1 Production and control of materials These days there can be few people who do not know that proteins are defined by DNA. DNA is made of two strands, each of which has along it, like a string of fairy lights, side branches that meet between the strands and hold them together.

  3. GRAPHENE: A NEW MATERIAL

    Directory of Open Access Journals (Sweden)

    Cătălin IANCU

    2011-07-01

    Full Text Available The paper presents the properties of a new but allready known material – graphene. Graphene is a 2-dimensional network of carbon atoms. Are presented the estonished characteristics of this form of carbon, alongwith some interesting field of use.

  4. Embodying material ideation

    DEFF Research Database (Denmark)

    Wilde, Danielle

    2015-01-01

    New materials and technologies offer the potential for highly innovative systems. Yet also challenge us to expand how we design. ‘Post-disciplinary embodied ideation’ is an emerging approach to knowledge generation and exchange amongst designers, scientists and the public. Its purpose is to enrich...

  5. Reactor Materials Research

    Energy Technology Data Exchange (ETDEWEB)

    Van Walle, E

    2001-04-01

    The activities of the Reactor Materials Research Department of the Belgian Nuclear Research Centre SCK-CEN in 2000 are summarised. The programmes within the department are focussed on studies concerning (1) fusion, in particular mechanical testing; (2) Irradiation Assisted Stress Corrosion Cracking (IASCC); (3) nuclear fuel; and (4) Reactor Pressure Vessel Steel (RPVS)

  6. Weightless Materials Science

    Science.gov (United States)

    Curtis, Jeremy

    2012-01-01

    Gravity affects everything we do. Only in very recent years have we been able to carry out experiments in orbit around the Earth and see for the first time how things behave in its absence. This has allowed us to understand fundamental processes better and to design new materials using this knowledge. (Contains 6 figures.)

  7. Desulfurization of fluid materials

    International Nuclear Information System (INIS)

    A method for desulfurizing fluid materials, comprising reacting sulfur to be removed with a rare earth compound, thereby forming rare earth sulfides, oxysulfides or mixtures thereof. The reaction is conducted under conditions of low oxygen potential. Rare earth sulfides and oxysulfides can be reacted with oxygen to restore a capacity for desulfurization

  8. Macrocyclic fragrance materials

    DEFF Research Database (Denmark)

    Salvito, Daniel; Lapczynski, Aurelia; Sachse-Vasquez, Christen;

    2011-01-01

    A screening-level aquatic environmental risk assessment for macrocyclic fragrance materials using a “group approach” is presented using data for 30 macrocyclic fragrance ingredients. In this group approach, conservative estimates of environmental exposure and ecotoxicological effects thresholds f...

  9. Materials Best Paper Award 2015

    OpenAIRE

    Maryam Tabrizian

    2015-01-01

    Materials has established an annual award for the best article and for the best review published in Materials in order to acknowledge the outstanding contributions of our authors in the area of materials science and engineering.[...

  10. Ceramic catalyst materials

    Energy Technology Data Exchange (ETDEWEB)

    Sault, A.G.; Gardner, T.J. [Sandia National Laboratories, Albuquerque, NM (United States); Hanprasopwattanna, A.; Reardon, J.; Datye, A.K. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-08-01

    Hydrous titanium oxide (HTO) ion-exchange materials show great potential as ceramic catalyst supports due to an inherently high ion-exchange capacity which allows facile loading of catalytically active transition metal ions, and an ability to be cast as thin films on virtually any substrate. By coating titania and HTO materials onto inexpensive, high surface area substrates such as silica and alumina, the economics of using these materials is greatly improved, particularly for the HTO materials, which are substantially more expensive in the bulk form than other oxide supports. In addition, the development of thin film forms of these materials allows the catalytic and mechanical properties of the final catalyst formulation to be separately engineered. In order to fully realize the potential of thin film forms of titania and HTO, improved methods for the deposition and characterization of titania and HTO films on high surface area substrates are being developed. By varying deposition procedures, titania film thickness and substrate coverage can be varied from the submonolayer range to multilayer thicknesses on both silica and alumina. HTO films can also be formed, but the quality and reproducibility of these films is not nearly as good as for pure titania films. The films are characterized using a combination of isopropanol dehydration rate measurements, point of zero charge (PZC) measurements, BET surface area, transmission electron microscopy (TEM), and elemental analysis. In order to assess the effects of changes in film morphology on catalytic activity, the films are being loaded with MoO{sub 3} using either incipient wetness impregnation or ion-exchange of heptamolybdate anions followed by calcining. The MoO{sub 3} is then sulfided to form MOS{sub 2}, and tested for catalytic activity using pyrene hydrogenation and dibenzothiophene (DBT) desulfurization, model reactions that simulate reactions occurring during coal liquefaction.

  11. Lightweight hydride storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.J.; Guthrie, S.E.; Bauer, W. [Sandia National Labs., Livermore, CA (United States)

    1995-09-01

    The need for lightweight hydrides in vehicular applications has prompted considerable research into the use of magnesium and its alloys. Although this earlier work has provided some improved performance in operating temperature and pressure, substantial improvements are needed before these materials will significantly enhance the performance of an engineered system on a vehicle. We are extending the work of previous investigators on Mg alloys to reduce the operating temperature and hydride heat of formation in light weight materials. Two important results will be discussed in this paper: (1) a promising new alloy hydride was found which has better pressure-temperature characteristics than any previous Mg alloy and, (2) a new fabrication process for existing Mg alloys was developed and demonstrated. The new alloy hydride is composed of magnesium, aluminum and nickel. It has an equilibrium hydrogen overpressure of 1.3 atm. at 200{degrees}C and a storage capacity between 3 and 4 wt.% hydrogen. A hydrogen release rate of approximately 5 x 10{sup -4} moles-H{sub 2}/gm-min was measured at 200{degrees}C. The hydride heat of formation was found to be 13.5 - 14 kcal/mole-H{sub 2}, somewhat lower than Mg{sub 2}Ni. The new fabrication method takes advantage of the high vapor transport of magnesium. It was found that Mg{sub 2}Ni produced by our low temperature process was better than conventional materials because it was single phase (no Mg phase) and could be fabricated with very small particle sizes. Hydride measurements on this material showed faster kinetic response than conventional material. The technique could potentially be applied to in-situ hydride bed fabrication with improved packing density, release kinetics, thermal properties and mechanical stability.

  12. Solar cell materials developing technologies

    CERN Document Server

    Conibeer, Gavin J

    2014-01-01

    This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

  13. Building Materials in Arctic Climate

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2005-01-01

    Building in the artic requires special attention on the appropriateness of building materials. The harsh climate makes execution difficult and sets unusual requirements for the pure material properties. In addition, there is a lack of choice of good, natural building materials in the arctic. This...... results in high transport costs. The building materials situation in Greenland may potentially be improved by intensifying the reuse of building materials or by promoting the local production of building materials....

  14. Materials Engineering Research Facility (MERF)

    Data.gov (United States)

    Federal Laboratory Consortium — Argonne?s Materials Engineering Research Facility (MERF) enables engineers to develop manufacturing processes for producing advanced battery materials in sufficient...

  15. Nanostructured electronic and magnetic materials

    Indian Academy of Sciences (India)

    R V Ramanujan

    2003-02-01

    Research and development in nanostructured materials is one of the most intensely studied areas in science. As a result of concerted R & D efforts, nanostructured electronic and magnetic materials have achieved commercial success. Specific examples of novel industrially important nanostructured electronic and magnetic materials are provided. Advantages of nanocrystalline magnetic materials in the context of both materials and devices are discussed. Several high technology examples of the use of nanostructured magnetic materials are presented. Methods of processing nanostructured materials are described and the examples of sol gel, rapid solidification and powder injection moulding as potential processing methods for making nanostructured materials are outlined. Some opportunities and challenges are discussed.

  16. Electrocaloric effect and luminescence properties of lanthanide doped (Na1/2Bi1/2)TiO3 lead free materials

    International Nuclear Information System (INIS)

    Polycrystalline lead-free Sodium Bismuth Titanate (NBT) ferroelectric ceramics doped with rare earth (RE) element are prepared using solid state reaction method. Optical, ferroelectric, and electrocaloric properties were investigated. The introduction of RE3+ ions in the NBT host lattice shows different light emissions over the wavelength range from visible to near infrared region. The ferroelectric P-E hysteresis loops exhibit an antiferroelectric-like character near room temperature indicating possible existence of a morphotropic phase boundary. The enhanced electrocaloric response was observed in a broad temperature range due to nearly merged phase transitions. Coexistence of optical and electrocaloric properties is very promising for photonics or optoelectronic device applications

  17. Handbook of Magnetic Materials

    International Nuclear Information System (INIS)

    Magnetoelectronics is a novel and rapidly developing field. This new field is frequently referred to as spin-electronics or spintronics. It includes spin-utilizing devices that need neither a magnetic field nor magnetic materials. In semiconductor devices, the spin of the carriers has only played a very modest role so far because well established semiconductor devices are non-magnetic and show only negligible effects of spin. Nanoscale thin films and multilayers, nanocrystalline magnetic materials, granular films, and amorphous alloys have attracted much attention in the last few decades, in the field of basic research as well as in the broader field of materials science. Such heterogeneous materials display uncommon magnetic properties that virtually do no occur in bulk materials. This is true, in particular with respect to surface (interface) magnetic anisotropy and surface (interface) magnetostrictive strains and giant magnetoresistance. The local atomic arrangement at the interface differs strongly from that in the bulk. The local symmetry is lowered, so that some interactions are changed or are missing altogether. The interface atoms may envisaged as forming a new phase and some properties characteristic of this phase may become predominant for the entire system. This becomes particularly evident in the case of interfacial magnetostriction which can lead to a decrease (almost to zero) or to an increase(over the bulk value) of the resulting magnetostriction of the nanoscale system. There are various forms of the interplay of magnetism and superconductivity, which can be divided into competition and coexistence phenomena. For instance, a strong competition is found in high-Tc cuprates. In these materials, depending on the doping rate, either Neel-type antiferromagnetism moments (e.g. from 4f-elements) with superconductivity is known to occur in systems where the concentration of these moments is sufficiently small or where they are antiferromagnetically ordered

  18. Materials management information systems.

    Science.gov (United States)

    1996-01-01

    The hospital materials management function--ensuring that goods and services get from a source to an end user--encompasses many areas of the hospital and can significantly affect hospital costs. Performing this function in a manner that will keep costs down and ensure adequate cash flow requires effective management of a large amount of information from a variety of sources. To effectively coordinate such information, most hospitals have implemented some form of materials management information system (MMIS). These systems can be used to automate or facilitate functions such as purchasing, accounting, inventory management, and patient supply charges. In this study, we evaluated seven MMISs from seven vendors, focusing on the functional capabilities of each system and the quality of the service and support provided by the vendor. This Evaluation is intended to (1) assist hospitals purchasing an MMIS by educating materials managers about the capabilities, benefits, and limitations of MMISs and (2) educate clinical engineers and information system managers about the scope of materials management within a healthcare facility. Because software products cannot be evaluated in the same manner as most devices typically included in Health Devices Evaluations, our standard Evaluation protocol was not applicable for this technology. Instead, we based our ratings on our observations (e.g., during site visits), interviews we conducted with current users of each system, and information provided by the vendor (e.g., in response to a request for information [RFI]). We divided the Evaluation into the following sections: Section 1. Responsibilities and Information Requirements of Materials Management: Provides an overview of typical materials management functions and describes the capabilities, benefits, and limitations of MMISs. Also includes the supplementary article, "Inventory Cost and Reimbursement Issues" and the glossary, "Materials Management Terminology." Section 2. The

  19. ALTERNATE MATERIALS IN DESIGN OF RADIOACTIVE MATERIAL PACKAGES

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, P.; Eberl, K.

    2010-07-09

    This paper presents a summary of design and testing of material and composites for use in radioactive material packages. These materials provide thermal protection and provide structural integrity and energy absorption to the package during normal and hypothetical accident condition events as required by Title 10 Part 71 of the Code of Federal Regulations. Testing of packages comprising these materials is summarized.

  20. Material efficiency in a multi-material world.

    Science.gov (United States)

    Lifset, Reid; Eckelman, Matthew

    2013-03-13

    Material efficiency--using less of a material to make a product or supply a service--is gaining attention as a means for accomplishing important environmental goals. The ultimate goal of material efficiency is not to use less physical material but to reduce the impacts associated with its use. This article examines the concept and definition of material efficiency and argues that for it to be an effective strategy it must confront the challenges of operating in a multi-material world, providing guidance when materials are used together and when they compete. A series of conceptions of material efficiency are described, starting with mass-based formulations and expanding to consider multiple resources in the supply chain of a single material, and then to multiple resources in the supply chains of multiple materials used together, and further to multiple environmental impacts. The conception of material efficiency is further broadened by considering material choice, exploring the technical and economic effects both of using less material and of materials competition. Finally, this entire materials-based techno-economic system is considered with respect to the impact of complex policies and political forces. The overall goal here is to show how the concept of material efficiency when faced with more expansive--and yet directly relevant--definitional boundaries is forced to confront analytical challenges that are both familiar and difficult in life cycle assessment and product-based approaches. PMID:23359743

  1. Transportation of nuclear materials

    International Nuclear Information System (INIS)

    The United States Department of Energy's Transportation Management Division (TMD) is responsible for assuring that the Department's shipments of nuclear materials are made in a safe, secure, efficient and economic manner. While stringent regulatory standards for materials packaging, carrier training and shipment routing are designed and followed to ensure a high level of f = safety in transportation, concerns about the risks of such shipments are often significant within communities along a shipping route. To address these concerns, DOE/TMD is 1988 began a cooperative program with public safety, health and planning professionals from the large city and urban county membership of the Urban Consortium for Technology Initiatives. With a focus on local issues, these practitioners defined a series of general concerns and assistance needs in areas of coordination, training, information and responder resources, marking and placarding, and costs and education

  2. Material tests for GFRP

    International Nuclear Information System (INIS)

    The physical and mechanical properties of GFRP at cryogenic temperatures have been studied for designing a large-sized GFRP dewar. As mechanical properties, the impact strength and the tensile strength have been investigated. From the results, it is shown that GFRP is not brittle at cryogenic temperatures, and the tensile strength increases with decreasing temperature. Therefore, it is adequate as a structural material at cryogenic temperatures. Anisotropy of tensile strength of the GFRP is so large that it has to be taken into account when GFRP is used as a structural material of the large-sized dewar. As thermal property, the thermal contraction has been investigated. The results show that the thermal contraction depends on the glass content and fiber direction. This anisotropy has to be taken into account for designing the dewar. (author)

  3. Twinning in nanocrystalline materials

    International Nuclear Information System (INIS)

    The deformation twinning of nanocrystalline materials is analyzed within the dislocation theory of twins. This approach is used for the description of the recently observed inverse grain size effect in nanocrystalline face-centered-cubic metals. The analytical expressions are obtained for the grain size corresponding to the peak of the twinning propensity, the requisite external stress for twinning propagation in polycrystals and the grain size at which the slip begins to prevail over the twinning. The theoretical results are compared with the experimental data for twinning in Ni and Cu, and given predictions for Al. -- Highlights: ► The inverse grain size effect in Ni and Cu is considered using dislocation theory. ► The twin growth stage of the deformation twinning in nc materials is analyzed. ► The theoretical results are compared with the experimental data for twinning. ► Given predictions the inverse grain size effect for Al.

  4. Designing Material Materialising Design

    DEFF Research Database (Denmark)

    Nicholas, Paul

    2013-01-01

    Designing Material Materialising Design documents five projects developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts, School of Architecture. These projects explore the idea that new designed materials might require new design methods....... Focusing on fibre reinforced composites, this book sustains an exploration into the design and making of elastically tailored architectural structures that rely on the use of computational design to predict sensitive interdependencies between geometry and behaviour. Developing novel concepts and...... operational models by which to specify and materialise causal relationships between configuration and transformation, these investigations reveal a new locus for architectural instruction that requires new kinds of design information, new representational models, and different modes of design control....

  5. Environmental Mineralogical Materials

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Basic properties, including surface absorption, porous filtration, ion exchange, heat effect and chemical solubility of environmental mineralogical materials, are widely applied to the pollution prevention environment improvement. The pollunian prevenition environmenr means the quality improvement of surface water, groundwater, river, lake and ground reservoir: the improvement of soil, the disposal of nuclear waste, the purification of domestic sewage, the collection of smoke and dust and the treatment of waste water. The prospective investigation and utilization of environmental mineralogical materials have been dealt with in more detail by the author of this paper with emphases on the prevention and control of soil contamination by heavy metals, on the quality im provement and treatment of surface water and groundwater,and on the collection of smoke and dust arising from burning coals.

  6. Sulphate resistant shielding material

    International Nuclear Information System (INIS)

    The shielding material of the present invention is provided with sulfuric acid resistance and contains bentonite put to ion exchange treatment with barium ions as an effective ingredient. When mortars and concretes are exposed to the circumstance of sulfate, the effective ingredient functions to take place reaction between intruding sulfate and the barium ions to form insoluble barium sulfate thereby reducing chemical corrosion of mortars and concretes caused by sulfate. Cement materials, water and aggregates can optionally be contained in addition to bentonite and bentonite put to ion exchange treatment. Chemical corrosion of concretes and mortars due to intrusion of the sulfate can be prevented, and it is useful as an artificial barrier, for example, in radioactive active waste processing facilities. (T.M.)

  7. Cohesion in real materials

    International Nuclear Information System (INIS)

    Theoretically calculated values of cohesion force density are compared with their values in real materials. Cohesion at the interface of twin inclusions in niobium at 4.2 K, slip bands in niobium at 77 K, slip bands in niobium oxidized and predeformed at 295 K after cooling down to 77 K, in slip bands of different hardened and tempered steels, at the boundaries of Al99.999 grains - in the process of torsional vibrations at 523 K, have been determined. To calculate cohesion force density and dry friction coefficient a two-member formula of dry friction is used. In all the cases cohesion force density of real materials was below its values calculated theoretically. Excess of yield limit and strengthening curve under compression over yield limit and strengthening curve under tension is explaind as a result of summation and subtraction of external stresses and cohesion forces

  8. Structural and Material Instability

    DEFF Research Database (Denmark)

    Cifuentes, Gustavo Cifuentes

    This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...... program based on the finite element method for the analysis of cracks in structural elements is presented; in this program the interface and elements with embedded discontinuities are implemented....... use of interface elements) is used successfully to model cases where the path of the discontinuity is known in advance, as is the case of the analysis of pull-out of fibers embedded in a concrete matrix. This method is applied to the case of non-straight fibers and fibers with forces that have...

  9. Polarons in advanced materials

    CERN Document Server

    Alexandrov, Alexandre Sergeevich

    2008-01-01

    Polarons in Advanced Materials will lead the reader from single-polaron problems to multi-polaron systems and finally to a description of many interesting phenomena in high-temperature superconductors, ferromagnetic oxides, conducting polymers and molecular nanowires. The book divides naturally into four parts. Part I introduces a single polaron and describes recent achievements in analytical and numerical studies of polaron properties in different electron-phonon models. Part II and Part III describe multi-polaron physics, and Part IV describes many key physical properties of high-temperature superconductors, colossal magnetoresistance oxides, conducting polymers and molecular nanowires, which were understood with polarons and bipolarons. The book is written in the form of self-consistent reviews authored by well-established researchers actively working in the field and will benefit scientists and postgraduate students with a background in condensed matter physics and materials sciences.

  10. Materials for advanced packaging

    CERN Document Server

    Lu, Daniel

    2010-01-01

    Significant progress has been made in advanced packaging in recent years. Several new packaging techniques have been developed and new packaging materials have been introduced. This book provides a comprehensive overview of the recent developments in this industry, particularly in the areas of microelectronics, optoelectronics, digital health, and bio-medical applications. The book discusses established techniques, as well as emerging technologies, in order to provide readers with the most up-to-date developments in advanced packaging.

  11. Ritualizing and Materializing Citizenship

    DEFF Research Database (Denmark)

    Damsholt, Tine

    2009-01-01

      This paper focuses on the possible transformation of the self in citizenship ceremonies in Western countries. It is argued that the transformation in these life defining moments is not only a question of ritual objectification or intentionality. The rituals are often experienced as emotional by....... These transformations engage a so called ‘ontological choreography' in which processes of ritual objectification and subjectification are intertwined, involving materiality, performativity, structural constraint, and the co-dependence of the performers....

  12. Advanced superconducting materials

    International Nuclear Information System (INIS)

    The superconducting properties of various materials are reviewed in view of their use in high field magnets. The critical current densities above 12 T of conductors based on NbN or PbMo6S8 are compared to those of the most advanced practical conductors based on alloyed by Nb3Sn. Different aspects of the mechanical reinforcement of high field conductors, rendered necessary by the strong Lorentz forces (e.g. in fusion magnets), are discussed. (orig.)

  13. Architects and Materials

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    One set of tools that has become predominant in the recent decades is the series of digital drawing and modelling software that today more than anything else defines the architect’s workflow. Digital drawing has become the keystone throughout the process from early sketching to building realisation...... and for which architecture is created. Through the interface of digital drawing, data can feed into digital production, linking the architect directly to the materials. Drawing can morph directly into materialisation instead of representation....

  14. Dictionary of materials testing

    International Nuclear Information System (INIS)

    This trilingual dictionary contains about 12000 terms from the field of non-destructive and destructive materials testing; the English and French terms can be looked up in two separate, alphabetical indexes. The compilation also presents terms from related fields such as quality control, production control, environmental protection and radiological protection, and wherever appropriate in the context from the fields of physics, chemistry, mathematics and electronic data processing. (HP)

  15. Material integrity verification radar

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has the need for verification of 'as-built' spent fuel-dry storage containers and other concrete structures. The IAEA has tasked the Special Technologies Laboratory (STL) to fabricate, test, and deploy a stepped-frequency Material Integrity Verification Radar (MIVR) system to nondestructively verify the internal construction of these containers. The MIVR system is based on previously deployed high-frequency, ground penetrating radar (GPR) systems that have been developed by STL for the U.S. Department of Energy (DOE). Whereas GPR technology utilizes microwave radio frequency energy to create subsurface images, MTVR is a variation for which the medium is concrete instead of soil. The purpose is to nondestructively verify the placement of concrete-reinforcing materials, pipes, inner liners, and other attributes of the internal construction. The MIVR system underwent an initial field test on CANDU reactor spent fuel storage canisters at Atomic Energy of Canada Limited (AECL), Chalk River Laboratories, Ontario, Canada, in October 1995. A second field test at the Embalse Nuclear Power Plant in Embalse, Argentina, was completed in May 1996. The DOE GPR also was demonstrated at the site. Data collection and analysis were performed for the Argentine National Board of Nuclear Regulation (ENREN). IAEA and the Brazilian-Argentine Agency for the Control and Accounting of Nuclear Material (ABACC) personnel were present as observers during the test. Reinforcing materials were evident in the color, two-dimensional images produced by the MIVR system. A continuous pattern of reinforcing bars was evident and accurate estimates on the spacing, depth, and size were made. The potential uses for safeguard applications were jointly discussed. The MIVR system, as successfully demonstrated in the two field tests, can be used as a design verification tool for IAEA safeguards. A deployment of MIVR for Design Information Questionnaire (DIQ

  16. Superconducting nanostructured materials

    International Nuclear Information System (INIS)

    Within the last year it has been realized that the remarkable properties of superconducting thin films containing a periodic array of defects (such as sub-micron sized holes) offer a new route for developing a novel superconducting materials based on precise control of microstructure by modern photolithography. A superconductor is a material which, when cooled below a certain temperature, loses all resistance to electricity. This means that superconducting materials can carry large electrical currents without any energy loss--but there are limits to how much current can flow before superconductivity is destroyed. The current at which superconductivity breaks down is called the critical current. The value of the critical current is determined by the balance of Lorentz forces and pinning forces acting on the flux lines in the superconductor. Lorentz forces proportional to the current flow tend to drive the flux lines into motion, which dissipates energy and destroys zero resistance. Pinning forces created by isolated defects in the microstructure oppose flux line motion and increase the critical current. Many kinds of artificial pinning centers have been proposed and developed to increase critical current performance, ranging from dispersal of small non-superconducting second phases to creation of defects by proton, neutron or heavy ion irradiation. In all of these methods, the pinning centers are randomly distributed over the superconducting material, causing them to operate well below their maximum efficiency. We are overcome this drawback by creating pinning centers in aperiodic lattice (see Fig 1) so that each pin site interacts strongly with only one or a few flux lines

  17. Fusion Reactor Materials

    International Nuclear Information System (INIS)

    SCK-CEN's programme on fusion reactor materials includes studies (1) to investigate fracture mechanics of neutron-irradiated beryllium; (2) to describe the helium behaviour in irradiated beryllium at atomic scale; (3) to define the kinetics of beryllium reacting with air or steam; (3) to perform a feasibility study for the testing of integrated blanket modules under neutron irradiation. Progress and achievements in 1997 are reported

  18. Ceramic Laser Materials

    OpenAIRE

    Guillermo Villalobos; Jasbinder Sanghera; Ishwar Aggarwal; Bryan Sadowski; Jesse Frantz; Colin Baker; Brandon Shaw; Woohong Kim

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers,...

  19. Materials for advanced packaging

    CERN Document Server

    Wong, CP

    2008-01-01

    Significant progress has been made in advanced packaging in recent years. Several new packaging techniques have been developed and new packaging materials have been introduced. This book provides a comprehensive overview of the recent developments in this industry, particularly in the areas of microelectronics, optoelectronics, digital health, and bio-medical applications. The book discusses established techniques, as well as emerging technologies, in order to provide readers with the most up-to-date developments in advanced packaging.

  20. Nano structured Magnetic Materials

    International Nuclear Information System (INIS)

    The saga of nanostructured magnetic materials (NMMs) has prevailed since the discovery of the first giant magnetoresistance (GMR) effect in metals in 1988. NMMs represent a unique system that incorporates the interplay between the properties associated with spin degrees of freedom and the nanoscaled structures, which provide a very strong platform for exploring both basic science and technical applications in the fields of solid-state physics, chemistry, materials science, and engineering. In fact, an active research field called “spintronics,” which has a big overlap with NMMs, has emerged and prevailed very recently. Through manipulation of spin of electrons in solids, a wide variety of NMMs and devices have been playing a prominent role in information processing and transport in our modern life. A rich variety of materials, such as transition metals, manganite, wide bandgap semiconductors, and nanocomposites, have already been developed for generating well-controlled nanostructures with new functionalities. Many scientists believe that the 21st century will be a “Century of Spin.” Nanomaterials and nanotechnologies have provided historical opportunities for research and development of novel spintronics materials and devices. NMSs manifest fascinating properties compared to the bulks because of size effect and quantum effect. Nanotechnologies have been proven to be an effective way to fabricate devices with fine nanostructures. The combination of spintronics and nanomaterials will undisputedly open new pathways in solid-state physics. The present special issue focuses on the recent development in the understanding of the synthesis, the studies on magnetic properties of nanostructures, and their potential applications based on the multiple functionalities.

  1. Electrochemistry reveals archaeological materials

    OpenAIRE

    Costa, Virginia; Leyssens, Karen; Adriaens, Annemie; Richard, N.; Scholz, Fritz

    2010-01-01

    The characterization of materials constituting cultural artefacts is a challenging step in their conservation, due to the object’s uniqueness and the reduced number of conservation institutes able to supply non-destructive analysis. We propose an alternative analytical tool, which combines accessibility (low cost and portable) and high sensitivity, based on electrochemical linear sweep voltammetry (LSV) with paraffin impregnated graphite electrode (PIGE). To investigate the composition of “wh...

  2. Crystalline Bioceramic Materials

    OpenAIRE

    Aza Moya, Antonio H. de; Aza, Piedad N. de; Aza Pendas, Salvador de

    2005-01-01

    [EN] A strong interest in the use of ceramics for biomedical engineering applications developed in the late 1960´s. Used initially as alternatives to metallic materials in order to increase the biocompatibility of implants, bioceramics have become a diverse class of biomaterials, presently including three basic types: relatively bioinert ceramics; bioactive or surface reactive bioceramics and bioresorbable ceramics. This review will only refer to bioceramics “sensus stricto”, it i...

  3. Radioactive material air transportation

    International Nuclear Information System (INIS)

    As function of the high aggregated value, safety regulations and the useful life time, the air transportation has been used more regularly because is fast, reliable, and by giving great security to the cargo. Based on the International Atomic Energy Agency (IAEA), the IATA (International Air Transportation Association) has reproduced in his dangerous goods manual (Dangerous Goods Regulations - DGR IATA), the regulation for the radioactive material air transportation. Those documents support this presentation

  4. Photopolymerizable hologram materials

    International Nuclear Information System (INIS)

    It is presented an overview of the current performances achieved in holography for the implementation of holographic gratings in photopolymerizable hologram materials. In particular, we dedicate an interest for the results associated to photomaterials belonging to the class of photopolymerizable glasses and the current applications. An overview of the main results on the current research at the Interdisciplinary Group for Optical Computing (GICO-UCM) at the Complutense University of Madrid is reported. (Author)

  5. Bulldozing of granular material

    OpenAIRE

    Sauret, A.; Balmforth, N. J.; Caulfield, C. P.; McElwaine, J. N.

    2014-01-01

    We investigate the bulldozing motion of a granular sandpile driven forwards by a vertical plate. The problem is set up in the laboratory by emplacing the pile on a table rotating underneath a stationary plate; the continual circulation of the bulldozed material allows the dynamics to be explored over relatively long times, and the variation of the velocity with radius permits one to explore the dependence on bulldozing speed within a single experiment. We measure the time-dependent surface sh...

  6. Realistic Material Appearance Modelling

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Filip, Jiří; Hatka, Martin

    2010-01-01

    Roč. 2010, č. 81 (2010), s. 13-14. ISSN 0926-4981 R&D Projects: GA ČR GA102/08/0593 Institutional research plan: CEZ:AV0Z10750506 Keywords : bidirectional texture function * texture modelling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2010/RO/haindl-realistic material appearance modelling.pdf

  7. Volume 2: Materials Science

    CERN Document Server

    Richter, Silvia; EMC 2008 14th European Microscopy Congress

    2008-01-01

    Proceedings of the14th European Microscopy Congress, held in Aachen, Germany, 1-5 September 2008. Jointly organised by the European Microscopy Society (EMS), the German Society for Electron Microscopy (DGE) and the local microscopists from RWTH Aachen University and the Research Centre Jülich, the congress brings together scientists from Europe and from all over the world. The scientific programme covers all recent developments in the three major areas of instrumentation and methods, materials science and life science.

  8. Superconducting doped topological materials

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Satoshi, E-mail: sasaki@sanken.osaka-u.ac.jp [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Mizushima, Takeshi, E-mail: mizushima@mp.es.osaka-u.ac.jp [Department of Materials Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Department of Physics, Okayama University, Okayama 700-8530 (Japan)

    2015-07-15

    Highlights: • Studies on both normal- and SC-state properties of doped topological materials. • Odd-parity pairing systems with the time-reversal-invariance. • Robust superconductivity in the presence of nonmagnetic impurity scattering. • We propose experiments to identify the existence of Majorana fermions in these SCs. - Abstract: Recently, the search for Majorana fermions (MFs) has become one of the most important and exciting issues in condensed matter physics since such an exotic quasiparticle is expected to potentially give rise to unprecedented quantum phenomena whose functional properties will be used to develop future quantum technology. Theoretically, the MFs may reside in various types of topological superconductor materials that is characterized by the topologically protected gapless surface state which are essentially an Andreev bound state. Superconducting doped topological insulators and topological crystalline insulators are promising candidates to harbor the MFs. In this review, we discuss recent progress and understanding on the research of MFs based on time-reversal-invariant superconducting topological materials to deepen our understanding and have a better outlook on both the search for and realization of MFs in these systems. We also discuss some advantages of these bulk systems to realize MFs including remarkable superconducting robustness against nonmagnetic impurities.

  9. Corrosion of melter materials

    International Nuclear Information System (INIS)

    A program was developed to characterize the effects of five variables on the corrosion rate of electrode and refractory materials: temperature, atmosphere inside the melter, composition of the glass, velocity, and electrochemical potential. As a data base for comparison in future tests, the corrosion rate was determined for Monofrax K - 3 (1.2 mils/day) and Inconel 690 (0.7 mils/day) in waste glass of the simulated reference SRP composition at 11500C in air. These tests were carried out as specified in ASTM C-621-68 (American Society for Testing materials) with a slight modification. After the specimens had been heated they were sectioned. The specimens were measured at the melt line cut and at the half down cut (halfway between the melt line cut and the bottom of the specimen). At least two reaction mechanisms occurred between the specimen and the molten glass: (1) Loss of Material reaction mechanisms resulted in a change in the dimensions of the specimen; and (2) Selective Penetration reaction mechanisms caused no change in the dimension of the specimens. The total amount of penetration was defined as the sum of attack by the two reactions. The corrosion rate increased with temperature and was proportional to the exponent 1/T

  10. Radiation shielding materials

    International Nuclear Information System (INIS)

    Purpose: To obtain putty-like shielding materials excellent in the radiation shielding and packing workability for use in penetrations of electrical wires or pipeways in a nuclear installation. Constitution: A putty-like material is prepared from 100 parts by weight of a binder comprising a grease or the like having viscosity of greater than 5000 cst or an immiscible consistency of greater than 100 (JIS K 2220 (1980) para. 5.3.4) at 25 0C and from 1200 to 4000 parts by weight of high density inorganic powder such as lead powder or lead oxide powder having a density of greater than 5 g/cm3 and such a particle size that more than 95 % thereof passes through a 145 mesh sieve. The putty-like material is adjusted such that it has 1 - 35 mm of softness (JIS A 5752) at normal temperature, more than 1 g/5 sec of injection amount and a density of greater than 4 g/cm3. In this way, non-curable radiation shielding agent with excellent X-ray or γ-ray shielding property and being capable of packed densely to void portions can be obtained. (Ikeda, J.)

  11. Steam generator materials

    International Nuclear Information System (INIS)

    In order to keep the nuclear power plant(NPP)s safe and increase their operating efficiency, axial stress corrosion cracking(SCC)(IGA/IGSCC, PWSCC, PbSCC) test techniques were developed and SCC property data of the archive steam generator tubing materials having been used in nuclear power plants operating in Korea were produced. The data obtained in this study were data-based, which will be used to clarify the damage mechanisms, to operate the plants safely, and to increase the lifetime of the tubing. In addition, the basic technologies for the improvement of the SCC property of the tubing materials, for new SCC inhibition, for damaged tube repair, and for manufacturing processes of the tubing were developed. In the 1 phase of this long term research, basic SCC test data obtained from the archive steam generator tubing materials used in NPPs operating in Korea were established. These basic technologies developed in the 1 phase will be used in developing process optimization during the 2 phase in order to develop application technologies to the field nuclear power plants

  12. High Thermal Conductivity Materials

    CERN Document Server

    Shinde, Subhash L

    2006-01-01

    Thermal management has become a ‘hot’ field in recent years due to a need to obtain high performance levels in many devices used in such diverse areas as space science, mainframe and desktop computers, optoelectronics and even Formula One racing cars! Thermal solutions require not just taking care of very high thermal flux, but also ‘hot spots’, where the flux densities can exceed 200 W/cm2. High thermal conductivity materials play an important role in addressing thermal management issues. This volume provides readers a basic understanding of the thermal conduction mechanisms in these materials and discusses how the thermal conductivity may be related to their crystal structures as well as microstructures developed as a result of their processing history. The techniques for accurate measurement of these properties on large as well as small scales have been reviewed. Detailed information on the thermal conductivity of diverse materials including aluminum nitride (AlN), silicon carbide (SiC), diamond, a...

  13. Energy Education Materials Inventory

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    The two volumes of the Energy Education Materials Inventory (EEMI) comprise an annotated bibliography of widely available energy education materials and reference sources. This systematic listing is designed to provide a source book which will facilitate access to these educational resources and hasten the inclusion of energy-focused learning experiences in kindergarten through grade twelve. EEMI Volume II expands Volume I and contains items that have become available since its completion in May, 1976. The inventory consists of three major parts. A core section entitled Media contains titles and descriptive information on educational materials, categorized according to medium. The other two major sections - Grade Level and Subject - are cross indexes of the items for which citations appear in the Media Section. These contain titles categorized according to grade level and subject and show the page numbers of the full citations. The general subject area covered includes the following: alternative energy sources (wood, fuel from organic wastes, geothermal energy, nuclear power, solar energy, tidal power, wind energy); energy conservation, consumption, and utilization; energy policy and legislation, environmental/social aspects of energy technology; and fossil fuels (coal, natural gas, petroleum). (RWR)

  14. Material and energy productivity.

    Science.gov (United States)

    Steinberger, Julia K; Krausmann, Fridolin

    2011-02-15

    Resource productivity, measured as GDP output per resource input, is a widespread sustainability indicator combining economic and environmental information. Resource productivity is ubiquitous, from the IPAT identity to the analysis of dematerialization trends and policy goals. High resource productivity is interpreted as the sign of a resource-efficient, and hence more sustainable, economy. Its inverse, resource intensity (resource per GDP) has the reverse behavior, with higher values indicating environmentally inefficient economies. In this study, we investigate the global systematic relationship between material, energy and carbon productivities, and economic activity. We demonstrate that different types of materials and energy exhibit fundamentally different behaviors, depending on their international income elasticities of consumption. Biomass is completely inelastic, whereas fossil fuels tend to scale proportionally with income. Total materials or energy, as aggregates, have intermediate behavior, depending on the share of fossil fuels and other elastic resources. We show that a small inelastic share is sufficient for the total resource productivity to be significantly correlated with income. Our analysis calls into question the interpretation of resource productivity as a sustainability indicator. We conclude with suggestions for potential alternatives. PMID:21210661

  15. Fracturing rigid materials.

    Science.gov (United States)

    Bao, Zhaosheng; Hong, Jeong-Mo; Teran, Joseph; Fedkiw, Ronald

    2007-01-01

    We propose a novel approach to fracturing (and denting) brittle materials. To avoid the computational burden imposed by the stringent time step restrictions of explicit methods or with solving nonlinear systems of equations for implicit methods, we treat the material as a fully rigid body in the limit of infinite stiffness. In addition to a triangulated surface mesh and level set volume for collisions, each rigid body is outfitted with a tetrahedral mesh upon which finite element analysis can be carried out to provide a stress map for fracture criteria. We demonstrate that the commonly used stress criteria can lead to arbitrary fracture (especially for stiff materials) and instead propose the notion of a time averaged stress directly into the FEM analysis. When objects fracture, the virtual node algorithm provides new triangle and tetrahedral meshes in a straightforward and robust fashion. Although each new rigid body can be rasterized to obtain a new level set, small shards can be difficult to accurately resolve. Therefore, we propose a novel collision handling technique for treating both rigid bodies and rigid body thin shells represented by only a triangle mesh. PMID:17218752

  16. Materials in the economy; material flows, scarcity, and the environment

    Science.gov (United States)

    Wagner, Lorie A.

    2002-01-01

    The importance of materials to the economy of the United States is described, including the levels of consumption and uses of materials. The paths (or flows) that materials take from extraction, through processing, to consumer products, and then final disposition are illustrated. Scarcity and environmental issues as they relate to the flow of materials are discussed. Examples for the three main themes of the report (material flows, scarcity, and the environment) are presented.

  17. Commentary: The Materials Project: A materials genome approach to accelerating materials innovation

    Science.gov (United States)

    Jain, Anubhav; Ong, Shyue Ping; Hautier, Geoffroy; Chen, Wei; Richards, William Davidson; Dacek, Stephen; Cholia, Shreyas; Gunter, Dan; Skinner, David; Ceder, Gerbrand; Persson, Kristin A.

    2013-07-01

    Accelerating the discovery of advanced materials is essential for human welfare and sustainable, clean energy. In this paper, we introduce the Materials Project (www.materialsproject.org), a core program of the Materials Genome Initiative that uses high-throughput computing to uncover the properties of all known inorganic materials. This open dataset can be accessed through multiple channels for both interactive exploration and data mining. The Materials Project also seeks to create open-source platforms for developing robust, sophisticated materials analyses. Future efforts will enable users to perform ``rapid-prototyping'' of new materials in silico, and provide researchers with new avenues for cost-effective, data-driven materials design.

  18. Multifunctional reactive nanocomposite materials

    Science.gov (United States)

    Stamatis, Demitrios

    Many multifunctional nanocomposite materials have been developed for use in propellants, explosives, pyrotechnics, and reactive structures. These materials exhibit high reaction rates due to their developed reaction interfacial area. Two applications addressed in this work include nanocomposite powders prepared by arrested reactive milling (ARM) for burn rate modifiers and reactive structures. In burn rate modifiers, addition of reactive nanocomposite powders to aluminized propellants increases the burn rate of aluminum and thus the overall reaction rate of an energetic formulation. Replacing only a small fraction of aluminum by 8Al·MoO3 and 2B·Ti nanocomposite powders enhances the reaction rate with little change to the thermodynamic performance of the formulation; both the rate of pressure rise and maximum pressure measured in the constant volume explosion test increase. For reactive structures, nanocomposite powders with bulk compositions of 8Al·MoO3, 12Al·MoO3, and 8Al·3CuO were prepared by ARM and consolidated using a uniaxial die. Consolidated samples had densities greater than 90% of theoretical maximum density while maintaining their high reactivity. Pellets prepared using 8Al·MoO3 powders were ignited by a CO2 laser. Ignition delays increased at lower laser powers and greater pellet densities. A simplified numerical model describing heating and thermal initiation of the reactive pellets predicted adequately the observed effects of both laser power and pellet density on the measured ignition delays. To investigate the reaction mechanisms in nanocomposite thermites, two types of nanocomposite reactive materials with the same bulk compositions 8Al·MoO3 were prepared by different methods. One of the materials was manufactured by ARM and the other, so called metastable interstitial composite (MIC), by mixing of nano-scaled individual powders. Clear differences in the low-temperature redox reactions, welldetectable by differential scanning calorimetry

  19. Novel Precursors for Chalcogenide Materials

    OpenAIRE

    Oyetunde, Temidayo Timothy

    2011-01-01

    The University of Manchester Temidayo Timothy Oyetunde, PhDNovel Chalcogenide Precursors for Materials2011.Abstract Metal chalcogenides (sulfides, selenides and tellurides) are materials of current interest due to their peculiar properties such as optoelectronic, magnetooptic, thermoelectric and piezoelectric displays. These semiconducting materials have potential applications in solar cell devices, infrared detectors and ambient thermoelectric generators. Previously, these materials...

  20. Cathode material for lithium batteries

    Science.gov (United States)

    Park, Sang-Ho; Amine, Khalil

    2013-07-23

    A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

  1. Platinum Group Metals New Material

    Institute of Scientific and Technical Information of China (English)

    XIE Ming; ZHANG Jiankang; WANG Saibei; HU Jieqiong; LIU Manmen; CHEN Yongtai; ZHANG Jiming; YANG Youcai; YANG Yunfeng; ZHANG Guoquan

    2012-01-01

    Platinum group metals (PGM) include six elements,namely Pt,Pd,Rh,Ir,Os and Ru.PGM and their alloys are the important fundamental materials for modern industry and national defense construction,they have special physical and chemical properties,widely used in metallurgy,chemical,electric,electronic,information,energy,environmental protection,aviation,aerospace,navigation and other high technology industry.Platinum group metals and their alloys,which have good plasticity and processability,can be processed to electrical contact materials,resistance materials,solder,electronic paste,temperature-measurement materials,elastic materials,magnetic materials and high temperature structural materials.

  2. Handbook of Advanced Magnetic Materials

    CERN Document Server

    Liu, Yi; Shindo, Daisuke

    2006-01-01

    From high-capacity, inexpensive hard drives to mag-lev trains, recent achievements in magnetic materials research have made the dreams of a few decades ago reality. The objective of Handbook of Advanced Magnetic Materials is to provide a timely, comprehensive review of recent progress in magnetic materials research. This broad yet detailed reference consists of four volumes: 1.) Nanostructured advanced magnetic materials, 2.) Characterization and simulation of advanced magnetic materials, 3.) Processing of advanced magnetic materials, and 4.) Properties and applications of advanced magnetic materials The first volume documents and explains recent development of nanostructured magnetic materials, emphasizing size effects. The second volume provides a comprehensive review of both experimental methods and simulation techniques for the characterization of magnetic materials. The third volume comprehensively reviews recent developments in the processing and manufacturing of advanced magnetic materials. With the co...

  3. High temperature materials and mechanisms

    CERN Document Server

    2014-01-01

    The use of high-temperature materials in current and future applications, including silicone materials for handling hot foods and metal alloys for developing high-speed aircraft and spacecraft systems, has generated a growing interest in high-temperature technologies. High Temperature Materials and Mechanisms explores a broad range of issues related to high-temperature materials and mechanisms that operate in harsh conditions. While some applications involve the use of materials at high temperatures, others require materials processed at high temperatures for use at room temperature. High-temperature materials must also be resistant to related causes of damage, such as oxidation and corrosion, which are accelerated with increased temperatures. This book examines high-temperature materials and mechanisms from many angles. It covers the topics of processes, materials characterization methods, and the nondestructive evaluation and health monitoring of high-temperature materials and structures. It describes the ...

  4. Irradiation environment and materials behavior

    International Nuclear Information System (INIS)

    Irradiation environment is unique for materials used in a nuclear energy system. Material itself as well as irradiation and environmental conditions determine the material behaviour. In this review, general directions of research and development of materials in an irradiation environment together with the role of materials science are discussed first, and then recent materials problems are described for energy systems which are already existing (LWR), under development (FBR) and to be realized in the future (CTR). Topics selected are (1) irradiation embrittlement of pressure vessel steels for LWRs, (2) high fluence performance of cladding and wrapper materials for fuel subassemblies of FBRs and (3) high fluence irradiation effects in the first wall and blanket structural materials of a fusion reactor. Several common topics in those materials issues are selected and discussed. Suggestions are made on some elements of radiation effects which might be purposely utilized in the process of preparing innovative materials. (J.P.N.) 69 refs

  5. Materials processing using supercritical fluids

    OpenAIRE

    Orlović Aleksandar M.; Skala Dejan U.

    2005-01-01

    One of the most interesting areas of supercritical fluids applications is the processing of novel materials. These new materials are designed to meet specific requirements and to make possible new applications in Pharmaceuticals design, heterogeneous catalysis, micro- and nano-particles with unique structures, special insulating materials, super capacitors and other special technical materials. Two distinct possibilities to apply supercritical fluids in processing of materials: synthesis of m...

  6. Cathode materials review

    International Nuclear Information System (INIS)

    The electrochemical potential of cathode materials defines the positive side of the terminal voltage of a battery. Traditionally, cathode materials are the energy-limiting or voltage-limiting electrode. One of the first electrochemical batteries, the voltaic pile invented by Alessandro Volta in 1800 (Phil. Trans. Roy. Soc. 90, 403-431) had a copper-zinc galvanic element with a terminal voltage of 0.76 V. Since then, the research community has increased capacity and voltage for primary (nonrechargeable) batteries and round-trip efficiency for secondary (rechargeable) batteries. Successful secondary batteries have been the lead-acid with a lead oxide cathode and a terminal voltage of 2.1 V and later the NiCd with a nickel(III) oxide-hydroxide cathode and a 1.2 V terminal voltage. The relatively low voltage of those aqueous systems and the low round-trip efficiency due to activation energies in the conversion reactions limited their use. In 1976, Wittingham (J. Electrochem. Soc., 123, 315) and Besenhard (J. Power Sources 1(3), 267) finally enabled highly reversible redox reactions by intercalation of lithium ions instead of by chemical conversion. In 1980, Goodenough and Mizushima (Mater. Res. Bull. 15, 783-789) demonstrated a high-energy and high-power LiCoO2 cathode, allowing for an increase of terminal voltage far beyond 3 V. Over the past four decades, the international research community has further developed cathode materials of many varieties. Current state-of-the-art cathodes demonstrate voltages beyond any known electrolyte stability window, bringing electrolyte research once again to the forefront of battery research

  7. Advanced materials processing

    International Nuclear Information System (INIS)

    Advanced materials will require improved processing methods due to high melting points, low toughness or ductility values, high reactivity with air or ceramics and typically complex crystal structures with significant anisotropy in flow and/or fracture stress. Materials for structural applications at elevated temperature in critical systems will require processing with a high degree of control. This requires an improved understanding of the relationship between process variables and microstructure to enable control systems to achieve consistently high quality. One avenue to the required level of understanding is computer simulation. Past attempts to do process modeling have been hampered by incomplete data regarding thermophysical or mechanical material behavior. Some of the required data can be calculated. Due to the advances in software and hardware, accuracy and costs are in the realm of acquiring experimental data. Such calculations can, for example, be done at an atomic level to compute lattice energy, fault energies, density of states and charge densities. These can lead to fundamental information about the competition between slip and fracture, anisotropy of bond strength (and therefore cleavage strength), cohesive strength, adhesive strength, elastic modulus, thermal expansion and possibly other quantities which are difficult (and therefore expensive to measure). Some of these quantities can be fed into a process model. It is probable that temperature dependencies can be derived numerically as well. Examples are given of the beginnings of such an approach for Ni3Al and MoSi2. Solidification problems are examples of the state-of-the-art process modeling and adequately demonstrate the need for extensive input data. Such processes can be monitored in terms of interfacial position vs. time, cooling rate and thermal gradient

  8. Transport of radioactive materials

    International Nuclear Information System (INIS)

    In Canada, large numbers of packages containing radioactive materials are shipped for industrial, medical and commercial purposes. The nature of the hazards and the associated risks are examined; the protection measures and regulatory requirements are indicated. The result of a survey on the number of packages being shipped is presented; a number of incidents are analyzed as a function of their consequences. Measures to be applied in the event of an emergency and the responsibility for the preparation of contingency plans are considered. (author)

  9. Heat Pipe Materials Compatibility

    Science.gov (United States)

    Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

    1976-01-01

    An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

  10. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  11. New Materialism: Interviews & Cartographies

    OpenAIRE

    van der Tuin, I.; Dolphijn, R.

    2012-01-01

    This book is the first monograph on the theme of “new materialism,” an emerging trend in 21st century thought that has already left its mark in such fields as philosophy, cultural theory, feminism, science studies, and the arts. The first part of the book contains elaborate interviews with some of the most prominent new materialist scholars of today: Rosi Braidotti, Manuel DeLanda, Karen Barad, and Quentin Meillassoux. The second part situates the new materialist tradition in contemporary tho...

  12. New auxetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Grima, J.N

    2000-06-01

    Materials with negative Poisson's ratios (auxetic) exhibit the very unusual property of becoming wider when stretched and narrower when squashed. This thesis presents a global classification system for auxetics based on the geometry and deformation mechanisms. Analytical expressions for the mechanical properties of several new two and three dimensional auxetic structures are derived. These structures involve rotating polygons, chiral units, re-entrant units, sliding wedges and helices. It is observed that the auxetic behaviour is scale independent and hence the structures may be implemented at either the macro, micro or nano level. These auxetic structures are used to explain the negative Poisson's ratios in a number of auxetic materials. A chiral structure is used to model auxetic polyurethane foams having broken ribs. A three dimensional re-entrant hinging/stretching structure is used to model auxetic ex-PTFE. Both models offer significant improvements when compared to previous work. Auxetic structures are also used as models for designing novel nanostructural molecular auxetics. In most cases, the auxeticity of these materials is confirmed through detailed molecular modelling. For example, crystalline molecular polyphenylacetylene networks based on the 'rotating triangles structure' are predicted to exhibit Poisson's ratios as low as -1, in accordance with their analytical models. These molecular networks are particularly interesting as they have all the six on-axis Poisson's ratios being concurrently negative. Their polycrystalline aggregates are also likely to be auxetic. The actual values of the mechanical properties are found to be dependent on the details of the molecular formulae (e.g. predicted single crystalline +0.25>V{sub zy}>-0.97, 250GPa>E{sub z}>2.4GPa). Some of these specific properties may be explained through the analytical models and offer the possibility of being able to design materials with tailor-made mechanical

  13. Nuclear Systems Materials Handbook

    International Nuclear Information System (INIS)

    The NSM Handbook is a multi-volume document being compiled on a continuing basis to meet the broad materials data requirements of those involved in the development of advanced nuclear energy systems. The present focus of the Handbook is upon nuclear systems that have not yet achieved commercial status, with near-term emphasis on the nation's Liquid Metal Fast Breeder Reactor Program. Actual use of the Handbook extends to other advanced nuclear concepts sharing the same needs, and to many nonnuclear engineering activities as well

  14. Integrated material accountancy system

    International Nuclear Information System (INIS)

    In this paper we present the system that we are actually using for Nuclear Material Accounting and Manufacturing Management in our UO2 Fuel Fabrication Plant located at Juzbado, Salamanca, Spain. The system is based mainly on a real time data base which gather data for all the operations performed in our factory from UO2 powder reception to fuel assemblies shipment to the customers. The accountancy is just an important part of the whole integrated system covering all the aspects related to manufacturing: planning, traceability, Q.C. analysis, production control and accounting data

  15. Advanced materials-2003

    International Nuclear Information System (INIS)

    The 8th International Symposium on Advanced Materials (ISAM) was held from 8-11 September, 2003. The proceeding of ISAM includes 87 papers which have been divided in to ten different sections. These include production and processing, coating and thin films, characterization, superconductors and semiconductors mechanical modeling, mechanical testing and life prediction composites, corrosion and oxidation, single crystals and related papers. Ten eminent researchers and scholars of international fame presented their keynote/invited lectures of 40 minutes each. This symposium provided an ideal opportunity for exchange of information amongst scientists, engineers, and researchers from all over Pakistan and 30 other countries of the world. (A.B.)

  16. Multiferroic materials tower up

    International Nuclear Information System (INIS)

    For generations humans have been engineering pillars that have more than one function. The giant stone pillars of the 9th-century Cordoba Mosque in Andalusia, Spain, for example, provide both structural stability and aesthetic appeal. Now researchers in the US have built pillar structures at the nanometre scale that combine two markedly different functions: magnetism and ferroelectricity. The technological importance of these 21st century nanopillars could be as far reaching as that of the ancient building techniques used in Andalusia. Magnetic materials are ubiquitous, from the huge transformer cores in electrical power sub-stations to the tiny magnetic particles that are used to store data on our computer disks. The widespread applications of magnets stem from two basic properties. First, they have a spontaneous magnetic moment, which enables magnetic flux to be concentrated in transformers. Second, the orientation of the magnetism can be switched back and forth by an applied magnetic field, and can therefore be used for data storage. Similarly, ferroelectric materials have a spontaneous electric polarization, the direction of which can be switched with an applied electric field. In fact, the 'ferro' part of the name arises because their electrical properties are similar to the magnetic properties of iron-based magnetic materials; most, however, are not ferrous in the sense that they contain iron. Ferroelectrics are used to make capacitors with high dielectric constants, and also have applications in nonvolatile data storage and sonar. Now, Haimei Zheng of the University of Maryland and colleagues in the US have adopted a different approach, which I believe is much more promising for producing useful magneto-electric multiferroics. Instead of trying to produce a single compound, they grow a closely interwoven composite material from magnetic cobalt ferrite (CoFe2O4) and ferroelectric barium titanate (BaTiO3). To do this, the team used a well established growth

  17. Superconducting materials and magnets

    International Nuclear Information System (INIS)

    The Technical Committee Meeting on Superconducting Materials and Magnets was convened by the IAEA and held by invitation of the Japanese government on September 4-6, 1989 in Tokyo. The meeting was hosted by the National Research Institute for Metals. Topics of the conference related to superconducting magnets and technology with particular application to fusion and the superconducting supercollider. Technology using both high and low-temperature superconductors was discussed. This document is a compendium of the papers presented at the meeting. Refs, figs and tabs

  18. A new Material Practice

    DEFF Research Database (Denmark)

    Tamke, Martin; Lafuente Hernández, Elisa; Deleuran, Anders;

    2012-01-01

    Advances in computational techniques allow for the integration of simulation in the initial design phase of architecture. This approach extends the range of the architectural intent to performative aspects of the overall structure and its elements. However, this also changes the process of design...... from the primacy of geometrical concerns to the negotiation between encoded parameters. Material behavior was the focus of the research project that led to the Dermoid 1:1 demonstrator build in Copenhagen. Dermoid was a 1:1 prototype, plywood structure that explored how the induced flex of plywood...

  19. New auxetic materials

    International Nuclear Information System (INIS)

    Materials with negative Poisson's ratios (auxetic) exhibit the very unusual property of becoming wider when stretched and narrower when squashed. This thesis presents a global classification system for auxetics based on the geometry and deformation mechanisms. Analytical expressions for the mechanical properties of several new two and three dimensional auxetic structures are derived. These structures involve rotating polygons, chiral units, re-entrant units, sliding wedges and helices. It is observed that the auxetic behaviour is scale independent and hence the structures may be implemented at either the macro, micro or nano level. These auxetic structures are used to explain the negative Poisson's ratios in a number of auxetic materials. A chiral structure is used to model auxetic polyurethane foams having broken ribs. A three dimensional re-entrant hinging/stretching structure is used to model auxetic ex-PTFE. Both models offer significant improvements when compared to previous work. Auxetic structures are also used as models for designing novel nanostructural molecular auxetics. In most cases, the auxeticity of these materials is confirmed through detailed molecular modelling. For example, crystalline molecular polyphenylacetylene networks based on the 'rotating triangles structure' are predicted to exhibit Poisson's ratios as low as -1, in accordance with their analytical models. These molecular networks are particularly interesting as they have all the six on-axis Poisson's ratios being concurrently negative. Their polycrystalline aggregates are also likely to be auxetic. The actual values of the mechanical properties are found to be dependent on the details of the molecular formulae (e.g. predicted single crystalline +0.25>Vzy>-0.97, 250GPa>Ez>2.4GPa). Some of these specific properties may be explained through the analytical models and offer the possibility of being able to design materials with tailor-made mechanical properties. Molecular systems based on

  20. Beyond the wonder material

    Science.gov (United States)

    Novoselov, Kostya

    2009-08-01

    When nature had to choose an element as the basis for life, it chose carbon. If I had to guess why, I would say the reason was carbon's extraordinary versatility. Bonding between carbon atoms is exceptionally strong; indeed, the strongest materials on Earth are all made of carbon. However, bonding between carbon and other elements, though stable, can easily be changed by chemical reactions. The resulting compounds are often surprisingly different from one another. For example, a pair of carbon atoms bonded together can accept one, two or three hydrogen atoms, forming ethyne, ethene and ethane - chemicals used in welding, anaesthesia and vodka-making, respectively.

  1. Material containment enclosure

    Science.gov (United States)

    Carlson, David O.

    1993-01-01

    An isolation enclosure and a group of isolation enclosures useful when a relatively large containment area is required. The enclosure is in the form of a ring having a section removed so that a technician may enter the center area of the ring. In a preferred embodiment, an access zone is located in the transparent wall of the enclosure and extends around the inner perimeter of the ring so that a technician can insert his hands into the enclosure to reach any point within. The inventive enclosures provide more containment area per unit area of floor space than conventional material isolation enclosures.

  2. Ordering, materiality and multiplicity

    DEFF Research Database (Denmark)

    van der Duim, René; Ren, Carina Bregnholm; Jóhannesson, Gunnar Thór

    2013-01-01

    In this article we discuss how ANT has been translated into tourism research and show how it has impacted the field by presenting three concepts integral to the ANT approach: ordering, materiality and multiplicity. We first introduce ANT and draw attention to current ANT studies in tourism......, followed by a discussion of how newer approaches within post-ANT urge us to face the ontological politics, which we engage in when performing tourism research. In conclusion we argue that ANT enables a radical new way at looking at tourism, tourism destinations and objects and investigations into the...... ontological condition of tourism....

  3. High Temperature Materials Characterization and Advanced Materials Development

    International Nuclear Information System (INIS)

    The project has been carried out for 2 years in stage III in order to achieve the final goals of performance verification of the developed materials, after successful development of the advanced high temperature material technologies for 3 years in Stage II. The mechanical and thermal properties of the advanced materials, which were developed during Stage II, were evaluated at high temperatures, and the modification of the advanced materials were performed. Moreover, a database management system was established using user-friendly knowledge-base scheme to complete the integrated-information material database in KAERI material division

  4. Aerogel nanocomposite materials

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A.J.; Ayers, M.; Cao, W. [Lawrence Berkeley Laboratory, CA (United States)] [and others

    1995-05-01

    Aerogels are porous, low density, nanostructured solids with many unusual properties including very low thermal conductivity, good transparency, high surface area, catalytic activity, and low sound velocity. This research is directed toward developing new nanocomposite aerogel materials for improved thermal insulation and several other applications. A major focus of the research has been to further increase the thermal resistance of silica aerogel by introducing infrared opacification agents into the aerogel to produce a superinsulating composite material. Opacified superinsulating aerogel permit a number of industrial applications for aerogel-based insulation. The primary benefits from this recently developed superinsulating composite aerogel insulation are: to extend the range of applications to higher temperatures, to provide a more compact insulation for space sensitive-applications, and to lower costs of aerogel by as much as 30%. Superinsulating aerogels can replace existing CFC-containing polyurethane in low temperature applications to reduce heat losses in piping, improve the thermal efficiency of refrigeration systems, and reduce energy losses in a variety of industrial applications. Enhanced aerogel insulation can also replace steam and process pipe insulation in higher temperature applications to substantially reduce energy losses and provide much more compact insulation.

  5. Target Housing Material Options

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-11

    With gas cooling, heat transfer coefficients are low compared to water. The benefit of gas from a heat transfer point of view is that there is really no upper temperature limit for the coolant, as compared to water, which is limited ultimately by the critical point, and in practice the critical heat flux. In our case with parallel flow channels, water is limited to even lower operating limits by nucleate boiling. So gas can get as hot as the containment material will allow, but to get the density and heat transfer up to something reasonable, we must also increase pressure, thus increasing stress on the containment, namely the front and back faces. We are designing to ASME BPVC, which, for most materials allows a maximum stress of UTS/3. So we want the highest possible UTS. For reference, the front face stress in the 12 mm target at 300 psi was about 90 MPa. The inconel 718 allowable stress at 900°C is 1/3 of 517 or 172 MPa. So we are in a very safe place, but the uTS is dropping rapidly with temperature above 900°C. As we increase target diameter, the challenge will be to keep the stress down. We are probably looking at keeping the allowable at or above the present value, and at as high a temperature as possible.

  6. Electroactivity in Polymeric Materials

    CERN Document Server

    2012-01-01

    Electroactivity in Polymeric Materials provides an in-depth view of the theory of electroactivity and explores exactly how and why various electroactive phenomena occur. The book explains the theory behind electroactive bending (including ion-polymer-metal-composites –IPMCs), dielectric elastomers, electroactive contraction, and electroactive contraction-expansion cycles.  The book also balances theory with applications – how electroactivity can be used – drawing inspiration from the manmade mechanical world and the natural world around us.  This book captures: A complete introduction to electroactive materials including examples and recent developments The theory and applications of numerous topics like electroactive bending of dielectric elastomers and electroactive contraction and expansion New topics, such as biomimetic applications and energy harvesting This is a must-read within the electroactive community, particularly for professionals and graduate students who are interested in the ...

  7. Irradiation of fusion materials

    International Nuclear Information System (INIS)

    In collaboration with the EFDA (European Fusion Development Agreement), SCK-CEN irradiates several materials in the BR2 reactor at different temperatures and up to different doses to study their mechanical and physical properties during and after the irradiation. These materials are candidates for the construction of different parts of the ITER (International Thermonuclear Experimental Reactor) fusion reactor and of the long-term DEMO (DEMOnstration) reactor. The objectives of research at SCK-CEN in this area are: (1) to irradiate RAFM (Reduced Activity Ferritic Martensitic) steel joints and RAFM ODS (Oxide Dispersion Strengthening) at 300 degrees Celsius up to 2 dpa; (2) to irradiate RAFM steel and different FeCr alloys at 300 degrees C above 1.5 dpa; (3) to irradiate Beryllium and Tungsten specimen at 300 degress C up to 0.75 dpa; (4) to irradiate copper/stainless steel joints at 150 degrees C up to 0.1 dpa; (5) to perform in-situ creep-fatigue tests with CuCrZr specimens under neutron irradiation

  8. Bulldozing of granular material

    CERN Document Server

    Sauret, A; Caulfield, C P; McElwaine, J N

    2014-01-01

    We investigate the bulldozing motion of a granular sandpile driven forwards by a vertical plate. The problem is set up in the laboratory by emplacing the pile on a table rotating underneath a stationary plate; the continual circulation of the bulldozed material allows the dynamics to be explored over relatively long times, and the variation of the velocity with radius permits one to explore the dependence on bulldozing speed within a single experiment. We measure the time-dependent surface shape of the dune for a range of rotation rates, initial volumes and radial positions, for four granular materials, ranging from glass spheres to irregularly shaped sand. The evolution of the dune can be separated into two phases: a rapid initial adjustment to a state of quasi-steady avalanching perpendicular to the blade, followed by a much slower phase of lateral spreading and radial migration. The quasi-steady avalanching sets up a well-defined perpendicular profile with a nearly constant slope. This profile can be scale...

  9. Neutrons for materials science

    International Nuclear Information System (INIS)

    The discussion will be limited to applied materials research performed on a customer/contractor basis. The information obtained using neutrons must therefore compete both scientifically and financially with information obtained using other techniques, particularly electron microscopy, X-ray, NMR, infra-red and Raman spectroscopy. It will be argued that the unique nature of the information gained from neutrons often outweighs the undoubted difficulties of access to neutron beams. Examples are given. Small angle scattering has emerged as the neutron technique of widest application in applied materials research. The penetration of neutron beams through containment vessels, as well as through the sample, allows the measurement of 'in situ' time dependent experiments within a furnace, cryostat, pressure vessel or chemical reactor vessel. High resolution powder diffraction is another technique with wide applications. Structural studies are possible on increasing complex phases. The structure and volume fraction of minority phases can be measured at levels appreciably below that possible by X-ray diffraction. A rapidly growing field at present is the measurement of internal strains through the small shifts in lattice spacing. Inelastic scattering measurements exploit the unique property of neutrons to measure the orientations of vibrating molecules. (author)

  10. Materials Microcharacterization Collaboratory

    Energy Technology Data Exchange (ETDEWEB)

    James C. Mabon; Gernot Metze; Ivan Petrov

    2003-02-20

    The Center for Microanalysis of Materials (CMM) is one of the four electron microscopy and microcharacterization user facilities participating in the Materials Microcharacterization Collaboratory (MMC) supported by the DOE-SC, Office of Basic Energy Science, and DOE Energy Efficiency & Renewable Energy Program, Office of Transportation Technology. The MMC unites the four DOE BES electron microscopy user facilities at ANL, LBNL, ORNL, and the CMM at the University of Illinois at Urbana-Champaign. Also participating in the MMC are the DOE EE microcharacterization user center at ORNL and the NAMT program at NIST. MMC also has several industrial partners. The purpose of the MMC is to bring the microanalytical and microcharacterization tools and expertise at these centers of excellence and other participating facilities together in an on-line interactive collaboratory and make them available to educators and researchers working in industry, universities, and government laboratories through telepresence access and operation. The MMC, however, is about remote collaboration, not just remote instrument control. The approach of the MMC also emphasizes providing the tools for establishing a sense of community and performing research using the MMC. The CMM has several instruments and peripherals available on-line emphasizing a Web-centric approach with varying levels of access and functionality. This program has developed and implemented hardware and software tools for remote and collaborative operation.

  11. Corrosion of support materials

    International Nuclear Information System (INIS)

    Results from a heavily fouled 19 tube C-E model boiler test to investigate the potential for egg crate corrosion in aggressively fouled AVT chemistry are reported. Substantial support plate and egg crate corrosion was produced in this test. Carbon steel drilled support plates exhibited extensive denting which resulted in flow hole ligament cracking. Corrosion of the carbon steel egg crate, through-wall at areas of tube contact, resulted in denting of the Alloy 600 heat transfer tubes. Corrosion performance of the 409 stainless steel egg crate was improved compared to the carbon steel egg crate although localized through-wall corrosion was noted. The results from the above test and previously reported tests were compared based on the following simplifying assumptions: maximum dent size and/or corrosion penetrations utilized, average bulk water chloride concentrations, pilling bedworth ratios, pot and model boilers data are equivalent, heat flux not significantly variable, and plot is semi-quantitative. Conclusions based on plots of maximum corrosion rates as a function of average bulk water chloride concentrations are presented. Finally, the corrosion performance of the various materials of construction for support systems were ranked for each test. Final material selection for future support systems must be based on a balance of thermal/hydraulic, metallurgical, corrosion and design considerations

  12. Laser processing of materials

    Indian Academy of Sciences (India)

    J Dutta Majumdar; I Manna

    2003-06-01

    Light amplification by stimulated emission of radiation (laser) is a coherent and monochromatic beam of electromagnetic radiation that can propagate in a straight line with negligible divergence and occur in a wide range of wavelength, energy/power and beam-modes/configurations. As a result, lasers find wide applications in the mundane to the most sophisticated devices, in commercial to purely scientific purposes, and in life-saving as well as life-threatening causes. In the present contribution, we provide an overview of the application of lasers for material processing. The processes covered are broadly divided into four major categories; namely, laser-assisted forming, joining, machining and surface engineering. Apart from briefly introducing the fundamentals of these operations, we present an updated review of the relevant literature to highlight the recent advances and open questions. We begin our discussion with the general applications of lasers, fundamentals of laser-matter interaction and classification of laser material processing. A major part of the discussion focuses on laser surface engineering that has attracted a good deal of attention from the scientific community for its technological significance and scientific challenges. In this regard, a special mention is made about laser surface vitrification or amorphization that remains a very attractive but unaccomplished proposition.

  13. The Science of Materials: from Materials Discovered by Chance to Customized Materials

    OpenAIRE

    Bréchet, Yves; Haroche, Serge

    2015-01-01

    Throughout the ages, humans have applied knowledge and know-how to master materials. They have gone from materials encountered by chance available in their environment to customized materials designed to meet multi-criteria specifications. Today, owing particularly to digital modelling on different scales, we are able to design high-performance materials, combining various classes of materials, in controlled geometries and dimensions. These innovation strategies – architectured or bio-inspire...

  14. Combinatorial sythesis of organometallic materials

    Science.gov (United States)

    Schultz, Peter G.; Xiang, Xiaodong; Goldwasser, Isy

    2002-07-16

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  15. Control of nuclear material specified equipment and specified material

    International Nuclear Information System (INIS)

    The goal and application field of NE 2.02 regulatory guide of CNEN (Comissao Nacional de Energia Nuclear), are described. This regulatory guide is about nuclear material management, specified equipment and specified material. (E.G.)

  16. Holistic evaluations of learning materials

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe; Hansen, Thomas Illum

    2011-01-01

    The aim of this paper is to present a holistic framework for evaluating learning materials and designs for learning. A holistic evaluation of learning material comprises investigations of - the potential learning potential, i.e. the affordances and challenges of the learning material, and the...... competences supposedly supported when working with the material - the actualized learning potential, i.e. the potential for learning when the design for learning is enacted by integrating the learning material in a situation in a given context, and - the actual learning, i.e. how the participants actually...... develop their competences through working with a learning material or enacting a design for learning....

  17. Surface Chemistry in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Alex V. Hamza

    2009-12-01

    Full Text Available Although surfaces or, more precisely, the surface atomic and electronic structure, determine the way materials interact with their environment, the influence of surface chemistry on the bulk of the material is generally considered to be small. However, in the case of high surface area materials such as nanoporous solids, surface properties can start to dominate the overall material behavior. This allows one to create new materials with physical and chemical properties that are no longer determined by the bulk material, but by their nanoscale architectures. Here, we discuss several examples, ranging from nanoporous gold to surface engineered carbon aerogels that demonstrate the tuneability of nanoporous solids for sustainable energy applications.

  18. Materials Compatibility of HVACR System Materials with Low GWP Refrigerants

    OpenAIRE

    Majurin, Julie A.; Gilles, William; Staats, Steven J.

    2014-01-01

    When assessing the suitability of next generation refrigerants for use with current HVACR system materials, two areas of concern need to be thoroughly investigated and understood: 1) chemical stability of the fluids when exposed to system materials under the anticipated conditions of use, and 2) compatibility of the system materials when in contact with the fluids. This paper will summarize materials compatibility evaluations of unsaturated hydrofluorocarbon (HFO) refrigerants, and HFO refrig...

  19. Composite material and method for production of improved composite material

    Science.gov (United States)

    Farley, Gary L. (Inventor)

    1996-01-01

    A laminated composite material with improved interlaminar strength and damage tolerance having short rods distributed evenly throughout the composite material perpendicular to the laminae. Each rod is shorter than the thickness of the finished laminate, but several times as long as the thickness of each lamina. The laminate is made by inserting short rods in layers of prepreg material, and then stacking and curing prepreg material with rods inserted therethrough.

  20. Disordered hyperuniform heterogeneous materials.

    Science.gov (United States)

    Torquato, Salvatore

    2016-10-19

    Disordered hyperuniform many-body systems are distinguishable states of matter that lie between a crystal and liquid: they are like perfect crystals in the way they suppress large-scale density fluctuations and yet are like liquids or glasses in that they are statistically isotropic with no Bragg peaks. These systems play a vital role in a number of fundamental and applied problems: glass formation, jamming, rigidity, photonic and electronic band structure, localization of waves and excitations, self-organization, fluid dynamics, quantum systems, and pure mathematics. Much of what we know theoretically about disordered hyperuniform states of matter involves many-particle systems. In this paper, we derive new rigorous criteria that disordered hyperuniform two-phase heterogeneous materials must obey and explore their consequences. Two-phase heterogeneous media are ubiquitous; examples include composites and porous media, biological media, foams, polymer blends, granular media, cellular solids, and colloids. We begin by obtaining some results that apply to hyperuniform two-phase media in which one phase is a sphere packing in d-dimensional Euclidean space [Formula: see text]. Among other results, we rigorously establish the requirements for packings of spheres of different sizes to be 'multihyperuniform'. We then consider hyperuniformity for general two-phase media in [Formula: see text]. Here we apply realizability conditions for an autocovariance function and its associated spectral density of a two-phase medium, and then incorporate hyperuniformity as a constraint in order to derive new conditions. We show that some functional forms can immediately be eliminated from consideration and identify other forms that are allowable. Specific examples and counterexamples are described. Contact is made with well-known microstructural models (e.g. overlapping spheres and checkerboards) as well as irregular phase-separation and Turing-type patterns. We also ascertain a family