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Sample records for high glass-forming ability

  1. Glass forming ability of calcium aluminosilicate melts

    DEFF Research Database (Denmark)

    Moesgaard, Mette; Yue, Yuanzheng

    2011-01-01

    The glass forming ability (GFA) of two series of calcium aluminosilicate melts is studied by measuring their viscous behavior and crystallization tendency. The first series consists of five compositions on the joining line between the eutectic point of anorthite-wollastonite-tridymite and that of......The glass forming ability (GFA) of two series of calcium aluminosilicate melts is studied by measuring their viscous behavior and crystallization tendency. The first series consists of five compositions on the joining line between the eutectic point of anorthite......-wollastonite-tridymite and that of anorthite-wollastonite-gehlenite. The series includes the eutectic compositions as end members. The second series consists of five compositions on a line parallel to the joining line on the alumina rich side. In the present work, GFA is described in terms of glass stability, i.e., the ability of a glass...... to resist crystallization during reheating. In addition, the fragility index (m) is derived by fitting the viscosity data with the Avramov-Milchev equation. The results show that m is inversely proportional to the glass stability for the two series of melts, implying that m is an indirect measure of GFA...

  2. A thermodynamic approach towards glass-forming ability of ...

    Indian Academy of Sciences (India)

    is known as the driving force of crystallization. The driving force of crystallization () provides very important information about the glass-forming ability (GFA) of metallic glasses (MGs). Lesser the driving force of crystallization more is the GFA. The varies linearly with the critical size (). According to Battezzati and ...

  3. Influence of preparation pathway on the glass forming ability

    DEFF Research Database (Denmark)

    Blaabjerg, Lasse Ingerslev; Lindenberg, Eleanor; Rades, Thomas

    2017-01-01

    The glass forming ability (GFA), i.e. the ease of amorphization of drugs, is mostly investigated using the critical cooling rate upon melt quenching to generate an amorphous product via the thermodynamic pathway. However, amorphous materials can also be prepared via the kinetic pathway by milling...

  4. Glass-Forming Ability of Soda Lime Borate Liquids

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Mauro, J.C.; Smedskjær, Morten Mattrup

    2012-01-01

    We investigate the composition dependence of glass-forming ability (GFA) of a series of iron-containing soda lime borate liquids by substituting Na2O for B2O3. We have characterized GFA by measuring the glass stability against crystallization using a differential scanning calorimeter (DSC). The r...

  5. Effects of minor Sn addition on the glass formation and properties of Fe-metalloid metallic glasses with high magnetization and high glass forming ability

    Science.gov (United States)

    Shi, Minjie; Liu, Zengqian; Zhang, Tao

    2015-03-01

    Effects of minor Sn addition on the glass-forming ability (GFA) as well as thermal, magnetic, and mechanical properties of Fe-P-C-B-Si bulk metallic glasses (BMGs) with compositions of Fe80-xSnxP9C8B2Si1 (x=0, 1, 2 and 3 at%) were investigated. The minor Sn substitution for Fe effectively enhances the GFA. The fully glassy rods can be produced up to 3 and 3.5 mm in diameter for the alloys with 1 and 2 at% Sn addition, respectively. Moreover, these Sn-containing BMGs exhibit good soft magnetic properties including high saturation magnetization (Ms) of 1.46-1.51 T, low coercivity (Hc) of 3.8-5.0 A/m and good mechanical properties, i.e., high fracture strength (σf) above 3.2 GPa and limited plastic strain (εp) above 0.4%. The combination of large GFA, good soft magnetic and mechanical properties as well as low cost makes the Fe-Sn-P-C-B-Si BMGs promising as soft magnetic materials for industrial applications.

  6. TOPICAL REVIEW On the glass forming ability of liquid alloys

    Directory of Open Access Journals (Sweden)

    Yoshio Waseda et al

    2008-01-01

    Full Text Available By using the concepts of the short-range order (SRO and middle-range order (MRO characterizing structures, an attempt has been made to describe the glass forming ability (GFA of liquid alloys. This includes the effect of more than two kinds of SRO in the liquid caused by the addition of second and third elements to a metallic solvent. The minimum solute concentration is related to the atomic volume mismatch estimated from the cube of the atomic radius. The optimum solute concentration for good glass formability in several binary and some ternary alloys is discussed on the basis of the empirical guideline. A new approach to obtaining good GFA of liquid alloys is based on four main factors: (i formation of new SRO and coexistence of two or more kinds of SRO, (ii stabilization of dense random packing structure by restraining the atomic redistribution for initiating the nucleation and growth process, (iii formation of a stable cluster (SC or the MRO by the harmonious coupling of SROs, and (iv difference between SRO characterizing the liquid structure and the near-neighbor environment in the corresponding equilibrium crystalline phases. The use of interaction parameters, widely used in the thermodynamics of multicomponent metallic solutions, is proposed for effectively selecting the third solute element (X3 for enhancing the GFA of a metallic liquid (M containing the second solute (X2. Fe70-B20-(X310 alloys (X3=Cr, W, Nb, Zr and Hf are used for illustration. Two typical model structures denoted by the Bernal and chemical-order types are used in describing the new glass structure as a function of solute concentration.

  7. Glass Forming Ability of Sub-Alkaline Silicate Melts

    Science.gov (United States)

    Vetere, F. P.; Iezzi, G.; Behrens, H.; Holtz, F.; Ventura, G.; Misiti, V.; Mollo, S.; Perugini, D.

    2014-12-01

    The glass forming ability (GFA) and critical cooling rate (Rc) of six natural sub-alkaline melts from basalt to rhyolite (i.e., B100, B80R20, B60R40, B40R60, B20R80, and R100) have been quantified through cooling-induced solidification experiments of 9000, 1800, 180, 60, 7 and 1 °C/h conducted at ambient pressure and air buffering conditions, in a temperature range between 1300 °C (superliquidus region) and 800 °C (glass transition region), The phase proportion in each run-product was determined by image analysis on about 500 BS-SEM microphotographs. The phase assemblage consists of glass, clinopyroxene, spinel, and plagioclase with the occurrence of sporadic olivine, orthopyroxene and melilite. Both the glass and crystalline fractions are well correlated with the composition of residual melt. Generally, the amount of crystals decreases with increasing cooling rate. However, some exceptions occurs showing no correlations or even opposite trends. For the example of, Al2O3 and CaO in clinopyroxenes from B100, B80R20, B60R40 and B40R60, their concentrations scale as a function of both cooling rate and the degree of clinopyroxene crystallization. The value of Rc changes of 5 order of magnitude from <1 to ~9000 °C/h when the melt composition changes from R100 to B100, respectively. The most important Rc variations are measured between B80R20 and B60R40, levelling off towards B100. This trend scales with NBO/T (non bridging oxygen per tetrahedron) and can be modelled by the following master sigmoid equation: Rc = a / 1+e-(NBO/T-xo/b), where a, b and xo are fitting parameters equal to 9214, 0.040 and 0.297, respectively. Our data can be used to retrieve the solidification conditions of aphyric, degassed and oxidised lavas. Indeed, the relationship between crystal content and cooling kinetics suggests that the solidification path is more complex than previously assumed and strongly non-linear. This finding has also implications to design glass-ceramics based on natural

  8. Accurate quantification of glass-forming ability by measuring effective volume relaxation of supercooled melt

    Science.gov (United States)

    Ryu, C. W.; Kang, D. H.; Jeon, S.; Lee, G. W.; Park, E. S.

    2017-10-01

    Herein, we elucidate how to accurately quantify glass-forming ability (GFA) by measuring effective volume relaxation of supercooled melt. We propose a new parameter, denoted as κ, for representing the relaxation, which is calculated by combining temperature-dependent changes of normalized specific volume reflecting relative volume relaxation with the normalized temperature range reflecting the relative position of the C curve in a Time-Temperature-Transformation (TTT) diagram. The interrelationship between the κ parameter and critical cooling rate is elaborated by measuring V-T diagrams and TTT diagrams of Zr55Co26Al19 and Zr46Cu30.14Al8Ag8.36Be7.5 glass-forming alloys and discussed in comparison with representative GFA parameters reported up to date. These results would give us a guideline on how to precisely evaluate GFA by linking volumetric aspect to thermodynamic and kinetic aspects for glass formation and help develop customized glass-forming alloys as well as a highly precise control of glass formation process.

  9. Density and glass forming ability in amorphous atomic alloys: The role of the particle softness

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, Ian; Hudson, Toby; Harrowell, Peter [School of Chemistry, University of Sydney, Sydney, NSW (Australia)

    2016-04-14

    A key property of glass forming alloys, the anomalously small volume difference with respect to the crystal, is shown to arise as a direct consequence of the soft repulsive potentials between metals. This feature of the inter-atomic potential is demonstrated to be responsible for a significant component of the glass forming ability of alloys due to the decrease in the enthalpy of fusion and the associated depression of the freezing point.

  10. Glass forming ability of amorphous drugs investigated by continuous cooling- and isothermal transformation

    DEFF Research Database (Denmark)

    Blaabjerg, Lasse Ingerslev; Lindenberg, Eleanor; Löbmann, Korbinian

    2016-01-01

    be made. Continuous-cooling-transformation (CCT) and time-temperature-transformation (TTT) diagrams of the drugs were developed in order to predict the critical cooling rate necessary to convert the drug from the melt into an amorphous form. While TTT diagrams overestimated the actual critical cooling....../min). Thus, the glass forming ability can be predicted by the use of TTT diagrams. In contrast to TTT diagrams, CCT diagrams may not be suitable for small organic molecules due to poor separation of exothermic events, which makes it difficult to determine the zone of recrystallization. In conclusion......, this study shows that glass forming ability of drugs can be predicted by TTT diagrams....

  11. Correlation between the Arrhenius crossover and the glass forming ability in metallic glasses.

    Science.gov (United States)

    Wen, Tongqi; Yao, Wenjing; Wang, Nan

    2017-10-13

    The distinctive characteristic of the metallic glass-forming system is that the variation in viscosity with temperature obeys Vogel-Fulcher-Tammann (VFT) relationship in the undercooled state and Arrhenius relationship in the high temperature region. A dimensionless index has thus been proposed based on the Arrhenius-VFT crossover and the classical nucleation rate and growth rate theory to evaluate the glass-forming ability (GFA). The indicator G(a) is expressed with the combination of T g , the glass transition temperature, T x , the onset crystallization temperature, T l , the liquidus temperature, T 0, the VFT temperature, and a a constant that could be determined according to the best correlation between G(a) and the critical cooling rate (R c ). Compared with other GFA indexes, G(a) shows the best fit with R c , with the square of the correlation coefficient (R (2)) being 0.9238 when a = 0.15 for the 23 various alloy systems concerned about. Our results indicate the crossover in the viscosity variation has key effect on GFA and one can use the index G(a) to predict R c and GFA for different alloys effectively.

  12. New amorphous alloy with high glass forming ability on the Cu-Zr-Al-Gd system; Desenvolvimento de nova liga com estrutura amorfa no sistema Cu-Zr-Al-Gd

    Energy Technology Data Exchange (ETDEWEB)

    Mazzer, E.M.; Aliaga, L.C.R.; Bolfarini, C.; Botta Filho, W.J.; Kiminami, C.S., E-mail: eric_mazzer@hotmail.co [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    The prediction of the Glass Forming Ability (GFA) in metallic alloys is usually performed by empirical or semi-empirical criteria in binary or ternary systems. For multi-component systems with more than three elements, the criteria or models become extremely complex making it impractical. In this paper we present the results on the GFA prediction of the Cu-Zr-Al-Gd alloys, where compositions had been selected for the synergy of the topological instability and electronegativity criteria which was increased by the average radio criterion for the quaternary system. Alloys were prepared and processed by arc-meting and die casting techniques. Characterization was made by x-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) techniques. It was concluded that Cu{sub 39,2}Zr{sub 49}Al{sub 9}, {sub 80}Gd{sub 2} alloy presents high thermal stability expressed by great supercooled liquid region upper to 76 deg C. (author)

  13. Multiscale structures of Zr-based binary metallic glasses and the correlation with glass forming ability

    Directory of Open Access Journals (Sweden)

    Xuelian Wu

    2017-08-01

    Full Text Available Thermal behaviors and structures of three Zr-based binary glass formers, Zr50Cu50, Zr64Cu36 and Zr64Ni36, were investigated and compared using differential scanning calorimetry (DSC, transmission electron microscopy (TEM, high energy X-ray diffraction (XRD and small angle X-ray scattering (SAXS. The high energy XRD results show that the bulk glass former Zr50Cu50 has a denser atomic packing efficiency and reduced medium-range order than those of marginal glass formers Zr64Cu36 and Zr64Ni36. Based on TEM observations for the samples after heat treatment at 10 K above their crystallization onset temperatures, the number density of crystals for Zr50Cu50 was estimated to be 1023–1024 m−3, which was four-orders higher than that in Zr64Cu36 and Zr64Ni36 metallic glasses. SAXS results indicate that Zr50Cu50 has higher degree of nanoscale inhomogeneities than those in Zr64Cu36 and Zr64Ni36 at as-cast state. The observed multiscale structures are discussed in terms of the phase stability and glass-forming ability of Zr-based binary glass formers.

  14. Computational predictions of glass-forming ability and crystallization tendency of drug molecules.

    Science.gov (United States)

    Alhalaweh, Amjad; Alzghoul, Ahmad; Kaialy, Waseem; Mahlin, Denny; Bergström, Christel A S

    2014-09-02

    Amorphization is an attractive formulation technique for drugs suffering from poor aqueous solubility as a result of their high lattice energy. Computational models that can predict the material properties associated with amorphization, such as glass-forming ability (GFA) and crystallization behavior in the dry state, would be a time-saving, cost-effective, and material-sparing approach compared to traditional experimental procedures. This article presents predictive models of these properties developed using support vector machine (SVM) algorithm. The GFA and crystallization tendency were investigated by melt-quenching 131 drug molecules in situ using differential scanning calorimetry. The SVM algorithm was used to develop computational models based on calculated molecular descriptors. The analyses confirmed the previously suggested cutoff molecular weight (MW) of 300 for glass-formers, and also clarified the extent to which MW can be used to predict the GFA of compounds with MW < 300. The topological equivalent of Grav3_3D, which is related to molecular size and shape, was a better descriptor than MW for GFA; it was able to accurately predict 86% of the data set regardless of MW. The potential for crystallization was predicted using molecular descriptors reflecting Hückel pi atomic charges and the number of hydrogen bond acceptors. The models developed could be used in the early drug development stage to indicate whether amorphization would be a suitable formulation strategy for improving the dissolution and/or apparent solubility of poorly soluble compounds.

  15. Glass-forming ability of compounds in marketed amorphous drug products.

    Science.gov (United States)

    Wyttenbach, Nicole; Kuentz, Martin

    2017-03-01

    This note is about the glass-forming ability (GFA) of drugs marketed as amorphous solid dispersions or as pure amorphous compounds. A thermoanalytical method was complemented with an in silico study, which made use of molecular properties that were identified earlier as being relevant for GFA. Thus, molar volume together with effective numbers of torsional bonds and hydrogen bonding were used to map drugs that are as amorphous products on the market either as solid dispersion of without co-processed carrier as amorphous drug in a solid dosage form. Differential scanning calorimetry experiments showed that most compounds were stable glass formers (GFs) (class III) followed by so-called unstable GFs (class II) and finally, only vemurafenib was found in class I with increased crystallization propensity. The in silico results, however showed that all drugs were either clearly in the chemical space expected for GFs or they were borderline to the region that holds for high crystallization tendency. Interestingly, the pure amorphous compounds scattered in a very confined region of the molecular predictors. These findings can guide amorphous product development of future drug candidates. Based on the compound location in the given chemical space, amorphous formulation opportunities can be balanced against the risks of physical instability upon storage. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. The fluidity and molding ability of glass-forming Zr-based alloy melt

    Science.gov (United States)

    Ma, Mingzhen; Zong, Haitao; Wang, Haiyan; Qi, Yanpeng; Liang, Sunxing; Song, Aijun; Zhang, Weiguo; Wang, Qiang; Zhang, Xinyu; Jing, Qin; Li, Gong; Liu, Riping

    2008-04-01

    The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically and experimentally. The major factors which affected the flowing behavior of the metallic melt in the mold were determined, which provides the foundation for overcoming the contradiction between the filling and formation of amorphous alloy during the rapid cooling process of the metallic melts. The casting factors to prepare a metallic ring were discussed and selected. As a result, a Zr-based bulk metallic glass ring was prepared successfully.

  17. Glass-Forming Ability and Early Crystallization Kinetics of Novel Cu-Zr-Al-Co Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Xiaoliang Han

    2016-09-01

    Full Text Available In recent years, CuZr-based bulk metallic glass (BMG composites ductilized by a shape memory B2 CuZr phase have attracted great attention owing to their outstanding mechanical properties. However, the B2 CuZr phase for most CuZr-based glass-forming compositions is only stable at very high temperatures, leading to the uncontrollable formation of B2 crystals during quenching. In this work, by introducing Co (i.e., 4, 5, and 6 at. % and 10 at. % Al into CuZr-based alloys, the relatively good glass-forming ability (GFA of CuZr-based alloys still can be achieved. Meanwhile, the B2 phase can be successfully stabilized to lower temperatures than the final temperatures of crystallization upon heating CuZr-based BMGs. Unlike previous reported CuZr-based BMGs, the primary crystallization products upon heating are mainly B2 CuZr crystals but not CuZr2 and Cu10Zr7 crystals. Furthermore, the primary precipitates during solidification are still dominated by B2 crystals, whose percolation threshold is detected to lie between 10 ± 2 vol. % and 31 ± 2 vol. %. The crystallization kinetics underlying the precipitation of B2 crystals was also investigated. Our results show that the present glass-forming composites are promising candidates for the fabrication of ductile CuZr-based BMG composites.

  18. Free volume: An indicator of the glass-forming ability in binary alloys

    Science.gov (United States)

    Liao, Bing.; Wu, Shi-yang; Yang, L.

    2017-10-01

    As a specific concept, free volume is proposed to affect the glass formation in alloys, while such issue remains unsolved, because free volume itself is ambiguous and elusive. In this work, the correlation between the free volume and the glass-forming ability (GFA) in some binary alloy systems has been investigated by a series of simulations combined with synchrotron-radiation based experiments. A new approach for detecting void spaces and even free volumes quantitatively in metallic glasses is developed, based on which we reveal that the size of free volumes significantly affects the glass formation. In particular, for ribbons with different compositions but the same thickness, a composition where there is a local maximum of GFA, there is a local bump of size value of free volumes, making it possible for free volumes to be an effective indicator of GFA. The present work provides new insight into the glass formation from free volume aspect, which can be helpful for understanding of both structure and properties in metallic glasses.

  19. Noncontact measurement of high-temperature surface tension and viscosity of bulk metallic glass-forming alloys using the drop oscillation technique

    OpenAIRE

    Mukherjee, S.; Johnson, W. L.; Rhim, W. K.

    2005-01-01

    High-temperature surface tension and viscosities for five bulk metallic glass-forming alloys with widely different glass-forming abilities are measured. The measurements are carried out in a high-vacuum electrostatic levitator using the drop oscillation technique. The surface tension follows proportional mathematical addition of pure components' surface tension except when some of the constituent elements have much lower surface tension. In such cases, there is surface segregation of the low ...

  20. Toward in silico prediction of glass-forming ability from molecular structure alone: a screening tool in early drug development.

    Science.gov (United States)

    Mahlin, Denny; Ponnambalam, Sopana; Höckerfelt, Mina Heidarian; Bergström, Christel A S

    2011-04-04

    We present a novel computational tool which predicts the glass-forming ability of drug compounds solely from their molecular structure. Compounds which show solid-state limited aqueous solubility were selected, and their glass-forming ability was determined upon spray-drying, melt-quenching and mechanical activation. The solids produced were analyzed by differential scanning calorimetry (DSC) and powder X-ray diffraction. Compounds becoming at least partially amorphous on processing were classified as glass-formers, whereas those remaining crystalline regardless of the process method were classified as non-glass-forming compounds. A predictive model of the glass-forming ability, designed to separate between these two classes, was developed through the use of partial least-squares projection to latent structure discriminant analysis (PLS-DA) and calculated molecular descriptors. In total, ten of the 16 compounds were determined experimentally to be good glass-formers and the PLS-DA model correctly sorted 15 of the compounds using four molecular descriptors only. An external test set was predicted with an accuracy of 75%, and, hence, the PLS-DA model developed was shown to be applicable for the identification of compounds that have the potential to be designed as amorphous formulations. The model suggests that larger molecules with a low number of benzene rings, low level of molecular symmetry, branched carbon skeletons and electronegative atoms have the ability to form a glass. To conclude, we have developed a predictive, transparent and interpretable computational model for the identification of drug molecules capable of being glass-formers. The model allows an assessment of amorphization as a formulation strategy in the early drug development process, and can be applied before compound synthesis.

  1. Physical stability of drugs after storage above and below the glass transition temperature: Relationship to glass-forming ability.

    Science.gov (United States)

    Alhalaweh, Amjad; Alzghoul, Ahmad; Mahlin, Denny; Bergström, Christel A S

    2015-11-10

    Amorphous materials are inherently unstable and tend to crystallize upon storage. In this study, we investigated the extent to which the physical stability and inherent crystallization tendency of drugs are related to their glass-forming ability (GFA), the glass transition temperature (Tg) and thermodynamic factors. Differential scanning calorimetry was used to produce the amorphous state of 52 drugs [18 compounds crystallized upon heating (Class II) and 34 remained in the amorphous state (Class III)] and to perform in situ storage for the amorphous material for 12h at temperatures 20°C above or below the Tg. A computational model based on the support vector machine (SVM) algorithm was developed to predict the structure-property relationships. All drugs maintained their Class when stored at 20°C below the Tg. Fourteen of the Class II compounds crystallized when stored above the Tg whereas all except one of the Class III compounds remained amorphous. These results were only related to the glass-forming ability and no relationship to e.g. thermodynamic factors was found. The experimental data were used for computational modeling and a classification model was developed that correctly predicted the physical stability above the Tg. The use of a large dataset revealed that molecular features related to aromaticity and π-π interactions reduce the inherent physical stability of amorphous drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The atomic-scale mechanism for the enhanced glass-forming-ability of a Cu-Zr based bulk metallic glass with minor element additions.

    Science.gov (United States)

    Wang, Q; Liu, C T; Yang, Y; Liu, J B; Dong, Y D; Lu, J

    2014-04-11

    It is known that the glass forming-ability (GFA) of bulk metallic glasses (BMGs) can be greatly enhanced via minor element additions. However, direct evidence has been lacking to reveal its structural origin despite different theories hitherto proposed. Through the high-resolution transmission-electron-microscopy (HRTEM) analysis, here we show that the content of local crystal-like orders increases significantly in a Cu-Zr-Al BMG after a 2-at% Y addition. Contrasting the previous studies, our current results indicate that the formation of crystal-like order at the atomic scale plays an important role in enhancing the GFA of the Cu-Zr-Al base BMG.

  3. Non-isothermal crystallization kinetics and glass-forming ability of Ti41Zr25Be28Fe6 bulk metallic glass investigated by differential scanning calorimetry

    Science.gov (United States)

    Gong, Pan; Zhao, Shaofan; Wang, Xin; Yao, Kefu

    2015-07-01

    The non-isothermal crystallization kinetics and glass-forming ability of Ti41Zr25Be28Fe6 glassy alloy were investigated by differential scanning calorimetry. The activation energies corresponding to the characteristic temperatures have been calculated by Kissinger and Ozawa equations. Based on Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall models, it has been found that the local activation energy is higher at the beginning of the crystallization process for the first exothermic peak. The local Avrami exponent indicates that the first-step crystallization is mainly a high-dimensional nucleation and growth with an increasing nucleation rate. According to the calculated fragility index, Ti41Zr25Be28Fe6 alloy can be classified as "strong glass former." The studied alloy also possesses a critical size up to centimeter order, and the high glass-forming ability is probably related to the relatively low Gibbs energy difference between the liquid and crystalline states. The critical cooling rate of Ti41Zr25Be28Fe6 glassy alloy has also been determined using Barandiaran-Colmenero's method.

  4. Effect of Multiple Alloying Elements on the Glass-Forming Ability, Thermal Stability, and Crystallization Behavior of Zr-Based Alloys

    Science.gov (United States)

    Bazlov, A. I.; Tsarkov, A. A.; Ketov, S. V.; Suryanarayana, C.; Louzguine-Luzgin, D. V.

    2018-02-01

    Effect of multiple alloying elements on the glass-forming ability, thermal stability, and crystallization behavior of Zr-based glass-forming alloys were studied in the present work. We investigated the effect of complete or partial substitution of Ti and Ni with similar early and late transition metals, respectively, on the glass-forming ability and crystallization behavior of the Zr50Ti10Cu20Ni10Al10 alloy. Poor correlation was observed between different parameters indicating the glass-forming ability and the critical size of the obtained glassy samples. Importance of the width of the crystallization interval is emphasized. The kinetics of primary crystallization, i.e., the rate of nucleation and rate of growth of the nuclei of primary crystals is very different from that of the eutectic alloys. Thus, it is difficult to estimate the glass-forming ability only on the basis of the empirical parameters not taking into account the crystallization behavior and the crystallization interval.

  5. The Effect of Purification on the Glass-Forming Ability of a Pd-Cu-Si Alloy

    Science.gov (United States)

    Ding, H. Y.; Li, Y.; Yang, G. N.; Yao, K. F.; QIU, S. B.

    2012-08-01

    The copper mold casting method is now commonly used for preparing bulk metallic glasses (BMGs). In the present work, it was found that, by employing the copper mold casting method, Pd77.5Cu6Si16.5 (at. pct) glassy rods with 1-mm diameter could be prepared, while the ϕ2-mm Pd77.5Cu6Si16.5 casting rod possesses some crystalline phases embedded within the glass matrix, confirming that the critical size of the glassy alloy is about 1 mm. By melt purification with fluxing treatment, the critical size of the glassy rod prepared by copper mold casting is increased to 4 mm. Based on thermal property analysis, it was found that melt purification by the fluxing method can greatly enhance the thermal stability and increase the glass forming ability (GFA) of the Pd-Cu-Si alloys. The as-prepared ϕ4-mm Pd-Cu-Si glassy rod exhibits a reduced glass transition temperature ( T rg ) of 0.599, a supercooled liquid region (Δ T) of 74 K (74 °C), and a γ parameter of 0.419.

  6. Effect of P addition on glass forming ability and soft magnetic properties of melt-spun FeSiBCuC alloy ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Yang, Y.Z., E-mail: yangyzgdut@163.com; Li, W.; Chen, X.C.; Xie, Z.W.

    2016-11-01

    The dependency of phosphorous content on the glass forming ability, thermal stability and soft magnetic properties of Fe{sub 83.4}Si{sub 2}B{sub 14−x}P{sub x}Cu{sub 0.5}C{sub 0.1} (x=0,1,2,3,4) alloys was investigated. The experimental results showed that the substitution of B by P increased the glass forming ability in this alloy system. The Fe{sub 83.4}Si{sub 2}B{sub 10}P{sub 4}Cu{sub 0.5}C{sub 0.1} alloy shows a fully amorphous character. Thermal stability of melt-spun ribbons increases and temperature interval between the first and second crystallization peaks enlarges with the increase of P content. And the saturation magnetic flux density (Bs) shows a slight increase with the increase of P content. The Fe{sub 83.4}Si{sub 2}B{sub 11}P{sub 3}Cu{sub 0.5}C{sub 0.1} nanocrystalline alloy exhibits a high Bs about 200.6 emu/g. The Bs of fully amorphous alloy Fe{sub 83.4}Si{sub 2}B{sub 10}P{sub 4}Cu{sub 0.5}C{sub 0.1} drops dramatically to 172.1 emu/g, which is lower than that of other nanocrystallines. Low material cost and excellent soft magnetic properties make the FeSiBPCuC alloys promise soft magnetic materials for industrial applications. - Highlights: • Partial substituting B by P helps to improve the glass forming ability of the alloy. • The addition of P content reduces the thermal stability and improves heat treatment temperature region for these alloys. • The Fe{sub 83.4}Si{sub 2}B{sub 11}P{sub 3}Cu{sub 0.5}C{sub 0.1} nanocrystalline alloy exhibits a high saturation magnetic density of 200.6 emu/g.

  7. Improvement of corrosion resistance in NaOH solution and glass forming ability of as-cast Mg-based bulk metallic glasses by microalloying

    Directory of Open Access Journals (Sweden)

    Peng Hao

    2011-02-01

    Full Text Available The influences of the addition of Ag on the glass forming ability (GFA and corrosion behavior were investigated in the Mg-Ni-based alloy system by X-ray diffraction (XRD and electrochemical polarization in 0.1 mol/L NaOH solution. Results shows that the GFA of the Mg-Ni-based BMGs can be improved dramatically by the addition of an appropriate amount of Ag; and the addition element Ag can improve the corrosion resistance of Mg-Ni-based bulk metallic glass. The large difference in atomic size and large negative mixing enthalpy in alloy system can contribute to the high GFA. The addition element Ag improves the forming speed and the stability of the passive film, which is helpful to decrease the passivation current density and to improve the corrosion resistance of Mg-Ni-based bulk metallic glass.

  8. Excellent Glass Forming Ability and Refrigeration Capacity of a Gd55Al20Ni12Co10Mn3 Bulk Metallic Glass

    Science.gov (United States)

    Ding, Ding; Wang, Peng; Guan, Quan; Tang, Mei-Bo; Xia, Lei

    2013-09-01

    We investigate an excellent refrigeration capacity Rc of Gd55Al20Ni12Co10Mn3 bulk metallic glass (BMG). The Gd55Al20Ni12Co10Mn3 glassy rod is subjected to Cu mold suction-casting to prepare bulky metallic glasses, with a diameter of 3mm. The glass forming ability as well as the magnetic properties of the BMG is investigated. The BMG exhibits a rather high glass formation ability with critical diameter of about 5.6mm. The peak value of magnetic entropy change of about 8 J·kg-1 K-1 is obtained in this alloy. This BMG alloy also exhibits excellent magnetic refrigerant capacity of about 880 J·kg-1 under the field of 5T and 35% larger than that of other alloys reported previously, supposed to be closely related to the high effective moment (~7.3μB) of the Gd55Al20Ni12Co10Mn3 BMG.

  9. Effects of minor Cu and Si additions on glass forming ability and mechanical properties of Co-Fe-Ta-B Bulk metallic glass

    Science.gov (United States)

    Yazici, Ziya Ozgur; Hitit, Aytekin; Yalcin, Yilmaz; Ozgul, Metin

    2016-01-01

    Effect of Cu and Si substitutions for Co and B on the glass forming ability (GFA) of Co(43-x)CuxFe20Ta5.5B(31.5-x)Siy (x=0-1.5 and y=5-10) were systematically investigated by X-ray diffraction, optical microscopy, scanning electron microscopy, and differential scanning calorimetry. In order to evaluate the contribution of copper and silicon, appropriate amounts of copper and silicon were individually introduced to the base alloy composition. By using the effects of copper and silicon together, significant enhancement was obtained and the critical casting thickness (CCT) of the base alloy was increased three times from 2 mm to 6 mm. Moreover, mechanical properties of the alloys were examined by compression tests and Vickers hardness measurements. The compression test results revealed that the glassy alloys having enhanced GFA shows high strength of about 3500-4000 MPa. In addition, existence of (Co,Fe)2B and (Co,Fe)20.82Ta2.18B6 crystalline phases in glassy matrix influences the hardnesses of the alloys compared to monolitic glassy structure having hardness of about 1200 Hv.

  10. Effects of additional Ag on the thermal stability and glass-forming ability of La-Al-Cu bulk glassy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jia Fei [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)], E-mail: jiafei@imr.tohoku.ac.jp; Zhang Wei; Kimura, Hisamichi; Inoue, Akihisa [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2008-02-25

    The addition of Ag to La-Al-Cu ternary glassy alloys greatly increases the stabilization of supercooled liquid and glass-forming ability (GFA). The large supercooled liquid region ({delta}T{sub x}) exceeding 60 K was obtained in a wide composition range of 10-22.5 at.% Al, 15-25 at.% Cu, and 2-12.5 at.% Ag. The largest {delta}T{sub x} of 83 K and the reduced glass transition temperature (T{sub g}/T{sub l}) were obtained for La{sub 62.5}Al{sub 12.5}Ag{sub 5}Cu{sub 20} alloy, leading to formation of the glassy alloy sample with a diameter of 6.0 mm. The addition of small amounts of Fe or Co to La-Al-Ag-Cu alloy increases T{sub g}/T{sub l} though the decrease in T{sub l}, resulting in an increase of GFA. As a result, the glassy alloy rods with diameters of over 7.0 mm were fabricated by addition of 2.5-5 at.% Fe or Co. The new La-based bulk glassy alloys exhibited high compressive fracture strength of 589-858 MPa with distinct plastic strain of 0.2-1.0%.

  11. Effect of Ni-substitution on glass forming ability, mechanical, and magnetic properties of FeBNbY bulk metallic glasses

    Science.gov (United States)

    Masood, Ansar; Ström, V.; Belova, L.; Rao, K. V.; Ågren, J.

    2013-01-01

    We present a method to identify bulk glass forming ability by partial substitution of Fe by Ni in FeBNbY based amorphous alloy ribbons and as a consequence obtain enhanced mechanical and soft magnetic properties of bulk glassy rods of diameter as large as 4.5 mm. A detailed investigation of thermal, mechanical, and magnetic properties of (Fe0.72-x NixB0.24Nb0.04)95.5Y4.5 alloys (with x ˜ 0.02, 0.04, 0.06, 0.08, 0.1) was carried out. The supercooled regime (ΔTx) and other glass forming parameters, e.g., reduced glass transition temperature (Trg), the gamma (γ) parameter, etc., were found to be enhanced due to the Ni substitution resulting in improvement of glass forming ability (GFA). The maximum values of such parameters (ΔTx ˜ 94 K, Trg ˜ 0.644, and γ ˜ 0.435) were obtained for the alloy with x ˜ 0.06, making it possible to cast cylindrical rods with 4.5 mm diameter for this composition. Nanoindentation studies on glassy rods also point out that (Fe0.66Ni0.06B0.24Nb0.04)95.5Y4.5 alloy exhibit the maximum value of hardness (H ˜ 12 GPa) as well as elastic modulus (E ˜ 193 GPa) among all of these samples. In addition to these, that particular sample shows the lowest room temperature coercivity (Hc ˜ 210 mOe). By annealing at 823 K, Hc can be further reduced to 60 mOe due to its structural relaxation. We attribute the improved soft magnetic and mechanical properties of as-quenched (Fe0.66Ni0.06B0.24Nb0.04)95.5Y4.5 alloy to higher packing density attained due to its large glass forming ability.

  12. Prediction of glass-forming ability and characterization of atomic structure of the Co-Ni-Zr metallic glasses by a proposed long range empirical potential

    Science.gov (United States)

    Ye, Dai; Jiahao, Li; Baixin, Liu

    2012-02-01

    An interatomic potential is constructed for the Co-Ni-Zr ternary metal system under long range empirical formalism and applied to conduct molecular dynamics simulations and Voronoi tessellations. Using solid solution models with varying solute concentrations, the simulations reveal that the physical origin of metallic glass formation is the crystalline lattice collapsing while solute concentration exceeding the critical solid solubility and determine a series of critical values. In the composition triangle, the determined critical solid solubilities define a quadrilateral region, in which the formation of Co-Ni-Zr ternary metallic glasses is favored and could therefore be considered as the quantitative glass-forming ability of the system. Voronoi tessellations indicate that the atomic structure of the Co-Ni-Zr ternary metallic glasses is obviously affected by the concentration of the component metals and that the differences of the atomic radii play the key role in influencing the atomic structure of the metallic glasses, e.g., for the Co50 - x/2Ni50 - x/2Zrx (15 popular polyhedrons, and they are almost Co- or Ni-centered. With increasing Zr concentration, the average coordination numbers of Co, Ni, or Zr decrease. When the Zr concentration is greater than 50 at. %, the fractions of {0, 0, 12, 0} icosahedrons and {0, 1, 12, 0} icosidihedrons decrease and the fraction of {0, 2, 8, 1} octadecahedrons remarkably increases. It turns out that the predicted glass-forming ability is well supported by the experimental observations so far reported in the literature.

  13. The fundamental structural factor in determining the glass-forming ability and mechanical behavior in the Cu-Zr metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sha, Z.D., E-mail: shaz@ihpc.a-star.edu.sg [Institute of High Performance Computing, 1 Fusionopolis Way, Singapore 138632 (Singapore); Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Feng, Y.P. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Li, Y. [Department of Materials Science and Engineering, National University of Singapore, Engineering Drive 1, Singapore 117576 (Singapore)

    2011-05-16

    Research highlights: {yields} A weak but significant hump in trend of the coordinate number and density was observed, respectively. {yields} Our findings indicate our simulation is more accurate to describe the atomic structure of Cu-Zr MGs. The composition-structure-properties correlation was established. {yields} And the effective structural unit for this correlation is the Cu-centered full icosahedra. - Abstract: Using the large-scale atomic/molecular massively parallel simulator, the quantitative composition-structure-properties (including glass-forming ability (GFA) and mechanical behavior) correlations in the Cu-Zr metallic glasses were established. The atomic-level origin of these correlations was tracked down. It was found that the Cu-centered full icosahedron is the microscopic factor that fundamentally influences both GFA and mechanical behavior. Our findings have implications for understanding the nature, forming ability and properties of metallic glasses, and for searching novel metallic glasses with unique functional properties.

  14. Effect of Si on the glass-forming ability, thermal stability and magnetic properties of Fe-Co-Zr-Mo-W-B alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.-M. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany); Key Lab of Liquid Structure and Heredity of Materials, Shandong University, Jinan 250061 (China); Gebert, A. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany)], E-mail: a.gebert@ifw-dresden.de; Roth, S.; Kuehn, U.; Schultz, L. [Institute for Metallic Materials, IFW Dresden, P.O. 270016, Dresden D-01171 (Germany)

    2008-07-14

    This paper presents investigations on the effect of Si on the glass-forming ability, thermal stability and magnetic properties of the Fe-Co-Zr-Mo-W-B samples (group I: Fe{sub 60}Co{sub 8}Zr{sub 10}Mo{sub 5}W{sub 2}B{sub 15-x}Si{sub x}, 1 {<=} x {<=} 4; group II: Fe{sub 60}Co{sub 8}Zr{sub 10-x}Mo{sub 5}W{sub 2}B{sub 15}Si{sub x}, 0 {<=} x {<=} 4; group III: Fe{sub 60}Co{sub 8}Zr{sub 8}Mo{sub 5}W{sub 2}B{sub 17-x}Si{sub x}, 0 {<=} x {<=} 2) prepared by melt spinning, injection casting, and centrifugal casting methods. It is found that the glass-forming ability (GFA) of the alloys in group I is more deteriorated than that in group II, and that the alloys in group III can be cast into the rods of 1-3 mm diameter without crystalline reflections in their XRD patterns. For the amorphous ribbons and rods, a non-monotonic change of the nearest neighbour distance r{sub 1} with increasing Si content c{sub Si} was detected, which is parallel to that of the glass transition and crystallization temperatures T{sub g} and T{sub x}, but opposite to that of the magnetization at room temperature M{sub RT} and the Curie temperature T{sub c}. This correlation can be interpreted by a structure model presuming that iron atoms appear simultaneously in two types of local structures in the amorphous samples.

  15. Non-isothermal crystallization kinetics and glass-forming ability of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} bulk metallic glass investigated by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Pan; Zhao, Shaofan; Yao, Kefu [Tsinghua University, School of Materials Science and Engineering, Beijing (China); Wang, Xin [Hebei University of Technology, School of Materials Science and Engineering, Tianjin (China)

    2015-07-15

    The non-isothermal crystallization kinetics and glass-forming ability of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} glassy alloy were investigated by differential scanning calorimetry. The activation energies corresponding to the characteristic temperatures have been calculated by Kissinger and Ozawa equations. Based on Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall models, it has been found that the local activation energy is higher at the beginning of the crystallization process for the first exothermic peak. The local Avrami exponent indicates that the first-step crystallization is mainly a high-dimensional nucleation and growth with an increasing nucleation rate. According to the calculated fragility index, Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} alloy can be classified as ''strong glass former.'' The studied alloy also possesses a critical size up to centimeter order, and the high glass-forming ability is probably related to the relatively low Gibbs energy difference between the liquid and crystalline states. The critical cooling rate of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} glassy alloy has also been determined using Barandiaran-Colmenero's method. (orig.)

  16. Glass forming ability of the Al-Ce-Ni system; Avaliacao da capacidade de formacao vitrea do sistema Al-Ce-Ni

    Energy Technology Data Exchange (ETDEWEB)

    Triveno Rios, C. [Engenharia Mecanica, Universidade Federal de Mato Grosso, Rondonopolis, MT (Brazil)], e-mail: triveno@ufmt.br; Surinach, S.; Baro, M.D. [Departamento de Engenharia de Materiais - Universidade Federal de Sao Carlos, SP (Brazil); Bolfarini, C.; Botta, W.J.; Kiminami, C.S. [Departamento de Fisica da Universidade Autonoma de Barcelona, Bellaterra (Spain)

    2010-07-01

    In the present work, the glass forming ability (GFA) and its compositional dependence on Al-Ni-Ce system alloys were investigated in function of several thermal parameters. Rapidly quenched Al{sub 85}Ni{sub 15}-{sub X}Ce{sub X} (X=4,5,6,7,10), Al{sub 90}Ni{sub 5}Ce{sub 5}, Al{sub 89}Ni{sub 2}.{sub 4}Ce{sub 8}.{sub 6}, Al{sub 80}Ni{sub 15.6}Ce{sub 4}.{sub 4} and Al{sub 78}Ni{sub 18.5}Ce{sub 3.5} amorphous ribbons were produced by melt-spinning and the structural transformation during heating was studied using a combination of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results showed that the GFA and the thermal stability in the Al-rich corner of Al- Ni-Ce system alloys were enhanced by increasing the solute content and specifically the Ce content (author)

  17. Study on glass-forming ability and hydrogen storage properties of amorphous Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0, 4) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Peng; Wang, Zhong-min, E-mail: zmwang@guet.edu.cn; Zhang, Huai-gang; Balogun, Muhammad-Sadeeq; Ji, Zi-jun; Deng, Jian-qiu; Zhou, Huai-ying

    2013-12-15

    Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0, 4) amorphous alloys were prepared by rapid solidification, using a melt-spinning technique. X-ray diffraction and differential scanning calorimetry analysis were employed to measure their microstructure, thermal stability and glass-forming ability, and hydrogen storage properties were studied by means of PCTPro2000. Based on differential scanning calorimetry results, their glass-forming ability and thermal stability were investigated by Kissinger method, Lasocka curves and atomic cluster model, respectively. The results indicate that glass-forming ability, thermal properties and hydrogen storage properties in the Mg-rich corner of Mg–Ni–La–Co system alloys were enhanced by Co substitution for La. It can be found that the smaller activation energy (ΔΕ) and frequency factor (υ{sub 0}), the bigger value of B (glass transition point in Lasocka curves), and higher glass-forming ability of Mg–Ni–La–Co alloys would be followed. In addition, atomic structure parameter (λ), deduced from atomic cluster model is valuable in the design of Mg–Ni–La–Co system alloys with good glass-forming ability. With an increase of Co content from 0 to 4, the hydrogen desorption capacity within 4000 s rises from 2.25 to 2.85 wt.% at 573 K. - Highlights: • Amorphous Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0 and 4) alloys were produced by melt spinning. • The GFA and hydrogen storage properties were enhanced by Co substitution for La. • With an increase of Co content, the hydrogen desorption capacity rises at 573 K.

  18. Kinetics, Thermodynamics, and Structure of Bulk Metallic Glass Forming Liquids

    Science.gov (United States)

    Busch, Ralf; Gallino, Isabella

    2017-11-01

    Bulk metallic glass forming melts are viscous liquids compared with pure metals and conventional alloys. They show intermediate kinetic fragility and low thermodynamic driving force for crystallization, leading to sluggish crystallization kinetics, leaving time for good glass forming ability and bulk casting thickness. We relate the kinetics to the thermodynamics of the supercooled liquid using the Adam-Gibbs equation. The kinetic fragility is also connected to the structural changes in the liquid and can be quantitatively linked to the robustness of medium-range order in the supercooled liquid with increasing temperature. Liquid-liquid transitions from fragile behavior at high temperature to strong behavior at low temperature in the supercooled liquid and in the vicinity of the glass transition emerge as a common phenomenon.

  19. Drastic influence of minor Fe or Co additions on the glass forming ability, martensitic transformations and mechanical properties of shape memory Zr-Cu-Al bulk metallic glass composites

    Science.gov (United States)

    González, Sergio; Pérez, Pablo; Rossinyol, Emma; Suriñach, Santiago; Baró, Maria Dolors; Pellicer, Eva; Sort, Jordi

    2014-06-01

    The microstructure and mechanical properties of Zr48Cu48 - x Al4M x (M ≡ Fe or Co, x = 0, 0.5, 1 at.%) metallic glass (MG) composites are highly dependent on the amount of Fe or Co added as microalloying elements in the parent Zr48Cu48Al4 material. Addition of Fe and Co promotes the transformation from austenite to martensite during the course of nanoindentation or compression experiments, resulting in an enhancement of plasticity. However, the presence of Fe or Co also reduces the glass forming ability, ultimately causing a worsening of the mechanical properties. Owing to the interplay between these two effects, the compressive plasticity for alloys with x = 0.5 (5.5% in Zr48Cu47.5Al4Co0.5 and 6.2% in Zr48Cu47.5Al4Fe0.5) is considerably larger than for Zr48Cu48Al4 or the alloys with x = 1. Slight variations in the Young’s modulus (around 5-10%) and significant changes in the yield stress (up to 25%) are also observed depending on the composition. The different microstructural factors that have an influence on the mechanical behavior of these composites are investigated in detail: (i) co-existence of amorphous and crystalline phases in the as-cast state, (ii) nature of the crystalline phases (austenite versus martensite content), and (iii) propensity for the austenite to undergo a mechanically-driven martensitic transformation during plastic deformation. Evidence for intragranular nanotwins likely generated in the course of the austenite-martensite transformation is provided by transmission electron microscopy. Our results reveal that fine-tuning of the composition of the Zr-Cu-Al-(Fe,Co) system is crucial in order to optimize the mechanical performance of these bulk MG composites, to make them suitable materials for structural applications.

  20. Highly processable bulk metallic glass-forming alloys in the Pt–Co–Ni–Cu–P system

    OpenAIRE

    Schroers, Jan; Johnson, William L.

    2004-01-01

    Highly processable bulk metallic glass alloys in the Pt–Co–Ni–Cu–P system were discovered. The alloys show low liquidus temperature below 900 K, excellent processability with low critical cooling rate reflecting in maximum casting thicknesses in quartz tubes of up to 20 mm, and a large supercooled liquid region. The Pt57.5Cu14.7Ni5.3P22.5 composition has a liquidus temperature of 795 K, a glass transition temperature of 508 K with a supercooled liquid region of 98 K. For medical and jewelry a...

  1. Glass forming ability and magnetic properties of Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) bulk metallic glasses produced by suction casting

    Energy Technology Data Exchange (ETDEWEB)

    Sarlar, Kagan [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Physics Department, Kamil Ozdag Faculty of Sciences, Karamanoglu Mehmetbey University, YunusEmre Campus, 70100 Karaman (Turkey); Kucuk, Ilker, E-mail: ikucuk@uludag.edu.tr [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey)

    2015-01-15

    The effect of Fe concentration on the glass forming ability (GFA) and magnetic properties in Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) bulk metallic glasses were investigated. By suction casting method, the bulk metallic glasses with diameters up to 2 mm were produced. We try to find out which Fe concentration makes an influence on Co based system's magnetic properties and glass forming ability. The curves of thermal analysis, obtained using differential scanning calorimetry (DSC), show that the Co{sub (40.2−x)}Fe{sub (20.1+x)}Ni{sub 6.7}B{sub 22.7}Si{sub 5.3}Nb{sub 5} (x=0–10) have a supercooled liquid region (∆T{sub x}) of about 44 K. The saturation magnetizations (J{sub s}) for as-cast BMG alloys were in the range of 0.62 T−0.81 T. - Highlights: • The effect of Fe concentration on the glass forming ability. • The substitution of an appropriate amount of Fe can enhance the GFA. • The substitution of Fe for Co also improves soft magnetic properties of the BMGs. • The high of J{sub s} 0.62−0.81 T with a low H{sub c} of 2−289 A/m of the alloys.

  2. Comparison of high pressure and nanoscale confinement effects on crystallization of the molecular glass-forming liquid, dimethyl phthalate.

    Science.gov (United States)

    Adrjanowicz, K; Szklarz, G; Koperwas, K; Paluch, M

    2017-06-07

    High pressure and nanoscopic confinement are two different strategies commonly employed to modify the physicochemical properties of various materials. Both strategies act mostly by changing the molecular packing. In this work, we performed a comparative study on the effect of compression and confined geometry on crystallization of a molecular liquid. Dielectric spectroscopy was employed to investigate the crystallization of the van der Waals liquid, dimethyl phthalate, in nanoporous alumina of different pore sizes as well as on increased pressure (up to 200 MPa). The analysis of the crystallization kinetics under varying thermodynamic conditions revealed that both strategies affect the crystallization behavior of the sample in very distinct ways. Compression shifts the maximum crystallization rate towards a higher temperature and broadens it. As a result, it is more challenging to avoid crystallization upon cooling the liquid at high pressure. In contrast, when the same material is incorporated into nanopores, crystallization significantly slows down and the maximum rate shifts towards a lower temperature with decreasing pore size. Finally, we show that crystallization in nanoporous alumina is accompanied by pre-crystallization effects upon which a shift of the α-relaxation peak is observed. An equilibration process prior to the initiation of crystallization was detected for the confined material both above and below the glass transition temperature of the interfacial layer, while not in the bulk.

  3. Effect of Industrial Raw Materials on the Glass-Forming Ability, Magnetic and Mechanical Properties of Fe-Based Bulk Metallic Glasses

    Science.gov (United States)

    Cai, Yongqian; Ling, Haibo; Jiang, Tao

    2015-12-01

    Pseudo-ternary Fe78P13C9 (the real composition is Fe77.6Si1.4P12.7C8.3) bulk metallic glasses (BMGs) with the maximum diameter of 1.5 mm based on industrial raw materials has been prepared by J-quenching technique using the master alloys with fluxing treatment, whereas fully amorphous alloy rod with the diameter of 1.0 mm cannot be obtained by the same preparation method using the master alloy without fluxing treatment. It is indicated that the glass formation ability (GFA) of the present Fe-based alloys based on industrial raw materials can be greatly enhanced through fluxing treatment. For comparison, the amorphous alloy rod with the same composition based on the pure raw materials has also been prepared by the same preparation technique and the critical diameter for fully glass formation gets to 2.0 mm. The DSC result indicates that the present Fe-based BMG based on industrial raw materials reveals higher thermal stability compared with the BMG based on pure raw materials. The magnetic tests show that the saturation magnetizations of the present Fe-based BMGs prepared by pure raw materials and industrial raw material are around 1.40 T, and have no significant difference. Compressive tests show that the present Fe-based BMG based on industrial raw materials exhibits higher compressive fracture strength (3.11 GPa) and slightly less plastic strain (0.8 pct) compared with the BMG based on pure raw materials with the same composition.

  4. Effect of Hafnium and Zirconium to Glass Forming Ability, Thermal Stability, Plasticity Deformation and Crystallization of Ni-Free Pentabasic Ti-Based Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Oak J.J.

    2017-06-01

    Full Text Available The newly designed Ti-based bulk metallic glass (BMG in which case of fracture behavior was observed 1990MPa to compressive strength with a wide plastic deformation around 7% after process of elastic deformation. This phenomenon can be compared with those of Ti-based alloys and other Ti-based BMGs and indicates high potential to be applied in use. It was evaluated the Ti-based BMG for thermal stability that the reduced glass parameters, ΔTx, Trg and γ, are 79K, 0.50 and 0.38, respectively. In addition, it reveals high activation energies for crystallization in which are estimated to Ex1 = 291.77 ±9.71 kJ/mol, Ex2 = 588.77 ±28.88 kJ/mol and Ex3 = 330.26 ±3.61 kJ/mol on kissinger plotting in this study.

  5. Effect of vanadium substitution for zirconium on the glass forming ability and mechanical properties of a Zr{sub 65}Cu{sub 17.5}Ni{sub 10}Al{sub 7.5} bulk metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Khademian, Nima, E-mail: nkhademian@gmail.com [Department of Mechanics, Islamshahr Branch, Islamic Azad University (IAU), Tehran (Iran, Islamic Republic of); Gholamipour, Reza [Iranian Research Organization for Science and Technology (IROST), Tehran (Iran, Islamic Republic of); Shahri, Farzad; Tamizifar, Morteza [Faculty of Engineering and High-Tech., Iran University of Industries and Mines (IUIM), Tehran (Iran, Islamic Republic of)

    2013-01-05

    Highlights: Black-Right-Pointing-Pointer The addition of V is effective for a decrease in GFA of Zr-based BMGs. Black-Right-Pointing-Pointer Mechanical properties of Zr-based BMGs are enhanced largely due to V addition. Black-Right-Pointing-Pointer Correlations among the elastic moduli, fracture strength, Vicker's hardness and glass transition for Zr-based BMGs. Black-Right-Pointing-Pointer Critical resolved shear stress ({tau}) of the Zr{sub 65-x}Cu{sub 17.5}Ni{sub 10}Al{sub 7.5}V{sub x} alloys decreases with the increase of V content. - Abstract: Effect of vanadium on the thermal and mechanical properties of the Zr{sub 65}Cu{sub 17.5}Ni{sub 10}Al{sub 7.5} bulk metallic glass has been studied. The vanadium substitution for zirconium in the bulk metallic glass leads to the decrease of the glass forming ability in constant cooling rate; as well as co-precipitation of Zr{sub 2}Ni and Zr{sub 2}Cu crystalline phases in amorphous matrix. The size of the crystallites are about 20-50 nm in amorphous matrix and they act as a barrier against of rapid propagation of shear bands. In fact, the nanocrystalline phases in amorphous matrix cause the increase of the strain and the quasi-static compression strength about 58% and 20%, respectively.

  6. High-temperature mass spectrometric study and modeling of thermodynamic properties of binary glass-forming systems containing Bi2O3.

    Science.gov (United States)

    Stolyarova, V L; Shilov, A L; Lopatin, S I; Shugurov, S M

    2014-04-15

    Binary glass-forming systems containing bismuth(III) oxide, especially the Bi2O3-SiO2 system, are of great importance in modern materials science: preparation of thin films, fiber optics, potential solar converters, and radiation shields in nuclear physics. Information on vaporization processes and thermodynamic properties obtained in the present study and the results of modeling of this system will be useful for optimization of the synthesis and applications of Bi2O3-containing materials at high temperatures. High-temperature Knudsen effusion mass spectrometry was used to study the vaporization processes and to determine the partial pressures of components of the Bi2O3-SiO2 system. Measurements were performed with a MS-1301 mass spectrometer. Vaporization was carried out using two iridium-plated molybdenum effusion cells containing the sample under study and pure bismuth(III) oxide (reference substance). Modeling of the thermodynamic properties and structure of glasses and melts in the Bi2O3-SiO2 and Bi2O3-B2O3 systems was performed using a modified approach based on the generalized lattice theory of associated solutions (GLTAS). At a temperature of 1000 K, Bi and O2 were found to be the main vapor species over the samples studied. The Bi2O3 activity as a function of composition of the Bi2O3-SiO2 system was obtained from the measured partial pressures of the vapor species. The thermodynamic properties of mixing from oxides in this system were calculated. The advantages of GLTAS for modeling of glasses and melts in the binary systems containing Bi2O3 were demonstrated. The thermodynamic functions of mixing in glasses and melts of the Bi2O3-SiO2 system determined at 1000 K in the present study, as well as in the Bi2O3-B2O3 system, demonstrated negative deviations from ideality. Modeling of the obtained experimental data using GLTAS allowed a correlation to be found between the thermodynamic properties and the relative number of bonds of various types formed in

  7. Thermodynamic and relative approach to compute glass-forming ...

    Indian Academy of Sciences (India)

    Abstract. This study deals with the evaluation of glass-forming ability (GFA) of oxides and is a critical reading of. Sun and Rawson thermodynamic approach to quantify this aptitude. Both approaches are adequate but ambiguous regarding the behaviour of some oxides (tendency to amorphization or crystallization). Indeed ...

  8. Diffusion and viscous flow in bulk glass forming alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, A.; Zoellmer, V.; Raetzke, K. [Institut fuer Materialwissenschaft - Materialverbunde, Technische Fakultaet, Christian-Albrechts Universitaet zu Kiel, Kaiserstr. 2, 24143 Kiel (Germany); Meyer, A. [Institut fuer Materialphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), 51170 Koeln (Germany); Faupel, F., E-mail: ff@tf.uni-kiel.de [Institut fuer Materialwissenschaft - Materialverbunde, Technische Fakultaet, Christian-Albrechts Universitaet zu Kiel, Kaiserstr. 2, 24143 Kiel (Germany)

    2011-06-15

    Research highlights: > We measured radiotracer diffusivities of all components in a Pd{sub 43}Cu{sub 27}Ni{sub 10}P{sub 20} melt. > We see a vast decoupling between the diffusivity of Pd and of the smaller components at T{sub g}. > We see no decoupling between Pd diffusion and viscous flow. > The Stokes-Einstein equations holds for Pd in the hole supercooled range. > Pd forms a slow subsystem. - Abstract: We review radiotracer diffusion and isotope measurements in bulk glass forming alloys from the glassy state to the equilibrium melt and compare diffusion and viscous flow. In the glassy as well as in the deeply supercooled state below the critical temperature T{sub c}, where the mode coupling theory predicts a freezing-in of liquid-like motion, very small isotope effects indicate a highly collective hopping mechanism. Not only in the glassy state but also in the supercooled state below T{sub c} the temperature dependence of diffusion is Arrhenius-like with an effective activation enthalpy. A clear decoupling takes place between the diffusivities of the individual components of the alloys and between time scales related to diffusive transport and viscous flow. While the component decoupling is small for the smaller components a vast decoupling of more than 4 orders of magnitude is observed in Pd-Cu-Ni-P alloys between the diffusivity of the large majority component Pd and of the smaller components at the glass transition temperature T{sub g}. The diffusivities of all components merge close to the critical temperature T{sub c} of mode coupling theory. Above T{sub c}, the onset of liquid-like motion is directly evidenced by a gradual drop of the effective activation energy. This strongly supports the mode coupling scenario. The isotope effect measurements show atomic transport up to the equilibrium melt to be far away from the regime of uncorrelated binary collisions. For Pd, in contrast to the behavior of single component molecular glass formers, the Stokes

  9. Microscopic dynamics of glass-forming polymers

    CERN Document Server

    Zorn, R

    2003-01-01

    The microscopic dynamics of glass-forming materials, especially polymers, is a topic of strong current interest and often heated debate. In this review an overview of the most common dynamical phenomena in glass-forming polymers will be presented: alpha relaxation, beta relaxation, 'boson peak', and 'fast process' (beta sub f sub a sub s sub t relaxation). The experimental results presented will be mainly from inelastic and quasielastic neutron scattering. Several mostly unanswered questions arise from the experimental findings, e.g.: Is the alpha relaxation of heterogeneous or homogeneous origin? Is there any relation between the ubiquitous low-temperature vibrational properties of glasses and the alpha relaxation? Different theoretical and model approaches will be mentioned, e.g. mode-coupling theory, the coupling model, the vibration-relaxation model. The limitations of these attempts will be demonstrated leading to the conclusion that currently there is no theory describing the microscopic dynamics of pol...

  10. Spinel dissolution via addition of glass forming chemicals. Results of preliminary experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States); Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-11-01

    Increased loading of high level waste in glass can lead to crystallization within the glass. Some crystalline species, such as spinel, have no practical impact on the chemical durability of the glass, and therefore may be acceptable from both a processing and a product performance standpoint. In order to operate a melter with a controlled amount of crystallization, options must be developed for remediating an unacceptable accumulation of crystals. This report describes preliminary experiments designed to evaluate the ability to dissolve spinel crystals in simulated waste glass melts via the addition of glass forming chemicals (GFCs).

  11. Highly improved reliability of amber light emitting diode with Ca -α-SiAlON phosphor in glass formed by gas pressure sintering for automotive applications.

    Science.gov (United States)

    Yoon, Chang-Bun; Kim, Sanghyun; Choi, Sung-Woo; Yoon, Chulsoo; Ahn, Sang Hyeon; Chung, Woon Jin

    2016-04-01

    Phosphor in glass (PiG) with 40 wt% of Ca-α-SiAlON phosphor and 60 wt% of Pb-free silicate glass was synthesized and mounted on a high-power blue LED to make an amber LED for automotive applications. Gas pressure sintering was applied after the conventional sintering process was used to achieve fully dense PiG plates. Changes in photoluminescence spectra and color coordination were inspected by varying the thickness of the plates that were mounted after optical polishing and machining. A trade-off between luminous flux and color purity was observed. The commercial feasibility of amber PiG packaged LED, which can satisfy international regulations for automotive components, was successfully demonstrated by examining the practical reliability under 85% humidity at an 85°C condition.

  12. Influence of Y, Gd and Sm on the glass forming ability and thermal crystallization of aluminum based alloy; Efeito das terras raras Y, Gd e Sm na tendencia a formacao de amorfo e na cristalizacao termica em ligas a base de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Aliaga, L.C.R.; Bolfarini, C.; Kiminami, C.S.; Botta Filho, W.J., E-mail: aliaga@ufscar.b [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais; Danez, G.P. [Universidade Federal de Sao Carlos (PPG-CEMUFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais

    2010-07-01

    Al-based amorphous alloys represent an important family of metals and a great scientific activity has been devoted to determine the main features of both glass forming ability (GFA) and crystallization behavior in order to have a comprehensive framework aimed at potential technological applications. Nowadays, it is well known that the best Al-based amorphous alloys are formed in ternary systems such as Al- RE-TM, where RE is a rare earth and TM a transition metal. This paper presents results of research in Al{sub 85}Ni{sub 10}RE{sub 5} alloys (RE = Y, Gd and Sm). Amorphous ribbons were processed by melt-spinning under the same conditions and subsequently characterized by x-ray diffraction (XRD) and differential scanning calorimetry (DSC). Results show appreciable micro structural differences as function of the rare earth, thus crystal is obtained for Y, nano-glassy for Gd and, fully amorphous structure for Sm. (author)

  13. A thermodynamic approach towards glass-forming ability of ...

    Indian Academy of Sciences (India)

    Abstract. A quantitative measure of the stability of a glass as compared to its corresponding crystalline state can be obtained by calculating the thermodynamic parameters, such as the Gibbs free energy difference ( G), entropy difference ( S) and the enthalpy difference ( H) between the super-cooled liquid and the ...

  14. Poor glass-forming ability of Fe-based alloys

    DEFF Research Database (Denmark)

    Zheng, H.J.; Hu, L.N.; Zhao, X.

    2017-01-01

    processes. By using the concept of fluid cluster and supercooled liquid fragility in metallic liquids, it has been found that this dynamic transition makes the Fe-based supercooled liquids become more unstable, which leads to the poor GFA of Fe-based alloys. Further, it has been found that the degree...

  15. Heterogeneous nucleation in a glass-forming alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wall, J. J. [Los Alamos National Laboratory (LANL); Liu, Chain T [ORNL; Rhim, W. K. [California Institute of Technology, Pasadena; Li, J. J. Z. [California Institute of Technology, Pasadena; Liaw, Peter K [University of Tennessee, Knoxville (UTK); Choo, H. [University of Tennessee, Knoxville (UTK); Huang, B. Y. [Central South University, China; Johnson, W. L. [California Institute of Technology, Pasadena

    2008-01-01

    Nucleation in the undercooled liquid state in the bulk metallic glass-forming composition Zr{sub 52.5}Cu{sub 17.9}Ni{sub 14.6}Al{sub 10}Ti{sub 5} (VIT-105), produced using high purity (PA) and commercial purity (CA) raw materials was investigated using electrostatic levitation and ex situ neutron diffraction. The CA material was observed to have a lower density than the PA sample and crystallized at relatively shallow undercooling. The densities of the samples at temperatures above the solidus showed an oxygen-dependent hysteresis associated with the state change, indicating the presence of oxygen-stabilized intermetallics. The PA alloy exhibited three distinct crystallization modes dependent on the thermal history of the melt, one of which showed a net volume expansion.

  16. High ability: Giftedness and talent

    Directory of Open Access Journals (Sweden)

    María Dolores Prieto Sánchez

    2010-04-01

    Full Text Available This special issue of the journal aims at putting together national and international research on high abilities, and is divided into three sections: 1 Roles and cognitive, emotional and professional competences of high ability students’ teachers, 2 Identification and assessment of high ability students, 3 Analysis of practices, programs and mentoring of high ability students’ attention to diversity.The articles are authored by scholars from nine different countries (Spain, Argentina, UK, USA, Russia, Brazil, Saudi Arabia, Portugal and Poland, from sixteen different Spanish and international universities: Alicante (Spain, Autónoma de Barcelona (Spain, Málaga (Spain, Murcia (Spain, Navarra (Spain, Oviedo (Spain, Tufts University (USA, Yale University (USA, Moscow State University (Russia, Nacional de La Plata (Argentina, University of Connecticut (USA, Universidade do Minho (Portugal, Universidade da Beira Interior (Portugal, Universidade do Estado do Rio de Janeiro (Brazil, King Faisal University (Saudi Arabia and Universidad de Szczecin (Poland.

  17. Laser engineered surfaces from glass forming alloy powder precursors : Microstructure and wear

    NARCIS (Netherlands)

    Matthews, D. T. A.; Ocelik, V.; Branagan, D.; de Hosson, J. Th. M.

    2009-01-01

    Fe-based metallic glass forming powders have been deposited on mild steel substrates using high power laser cladding. Coatings microstructures have been analysed by scanning- and transmission-electron microscopy and at varying substrate dilutions, have been found to comprise a 100 to 500 nm

  18. Low-energy excitations in a low-viscous glass-forming liquid

    Indian Academy of Sciences (India)

    Low-energy excitations in a low-viscous glass-forming liquid. ANGELOS G KALAMPOUNIAS. Department of Chemical Engineering, University of Patras, GR 26504, Patras, Greece and Foundation for Research and Technology Hellas – Institute of Chemical Engineering and High Temperature Chemical Processes, ...

  19. Glass-forming liquids: one or more "order" parameters"

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Christensen, Tage Emil; Jakobsen, Bo

    2008-01-01

    We first summarize the classical arguments that the vast majority of glass-forming liquids require more than one ‘order' parameter for their description. Critiques against this conventional wisdom are then presented, and it is argued that the matter deserves to be reconsidered in the light...... that a description with a single "order" parameter applies to a good approximation whenever thermal equilibrium fluctuations of fundamental variables like energy and pressure are strongly correlated. Results from computer simulations showing that this is the case for a number of simple glass-forming liquids, as well...

  20. The dynamic bulk modulus of three glass-forming liquids

    DEFF Research Database (Denmark)

    Niss, Kristine; Christensen, Tage Emil; Dyre, J. C.

    2014-01-01

    We present dynamic adiabatic bulk modulus data for three organic glass-forming liquids: two van der Waal's liquids, trimethyl-pentaphenyl-trisiloxane (DC705) and dibuthyl phtalate (DBP), and one hydrogen-bonded liquid, 1,2-propanediol (PD). All three liquids are found to obey time-temperature sup......We present dynamic adiabatic bulk modulus data for three organic glass-forming liquids: two van der Waal's liquids, trimethyl-pentaphenyl-trisiloxane (DC705) and dibuthyl phtalate (DBP), and one hydrogen-bonded liquid, 1,2-propanediol (PD). All three liquids are found to obey time...

  1. Teachers of high ability pupils

    Directory of Open Access Journals (Sweden)

    Cándido Genovard

    2010-04-01

    Full Text Available In this article we analyze the characteristics of gifted and talented students’ expert teachers. The subject background and the specific proprieties of the instructional process to meet gifted students’ educational needs are analyzed. The value of teacher-student interactions and of teaching and learning styles are highlighted. Also, we include different action guidelines and instructional resources to use in the classroom to teach these students. There is not an ideal teacher for high ability students. However, teachers must know what the teaching-learning processes are and how these work, and the diverse psychological, content and contextual variables involved in such processes.

  2. High Ability and Learner Characteristics

    Directory of Open Access Journals (Sweden)

    Huda Hindal

    2013-01-01

    Full Text Available The outstandingly able learner has been conceptualised, in terms of test and examination performance, as the learner showing superior academic performance which is markedly better than that of peers and in ways regarded as of value by wider society. In Kuwait, such superior examination performance leads to a classification regarded as being ‘gifted’. This study looks at the inter-correlations between performance in various subjects in examinations and then considers how examination performance correlates with measures of working memory capacity, extent of field dependency, extent of divergency and visual-spatial abilities. A very large sample of grade 7 Kuwaiti students (aged ~13 was involved, the sample being selected in such a way that it contained a high proportion of those regarded as ‘gifted’ under the procedures used in Kuwait. While specific learner characteristics have been related to examination performance, this study brings four different characteristics together to gain a picture of the way these characteristics may be seen in those who perform extremely well in examinations. Principal components analysis using varimax rotation, was used to look at the examination data and one factor accounted for 87% of the variance. A consideration of the examination papers led to the conclusion that the national examinations tested only recall-recognition. It was also found that those who performed best in all six subjects tended to be those who are highly divergent and strongly visual-spatial as well as those tending to have higher working memory capacities and being more field independent. The inter-correlations between the various learner characteristics are explained in terms of the way the brain is known to process information. The implications of the findings for assessment and for the way high ability is considered are discussed.

  3. Local elastic expansion model for viscous-flow activation energies of glass-forming molecular liquids

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Olsen, Niels Boye; Christensen, Tage Emil

    1996-01-01

    A model for the viscosity of glass-forming molecular liquids is proposed in which a "flow event" requires a local volume increase. The activation energy for a flow event is identified with the work done in shoving aside the surrounding liquid; this work is proportional to the high-frequency shear...... modulus, which increases as the temperature decreases. The model is confirmed by experiments on a number of molecular liquids....

  4. Fast and slow crystal growth kinetics in glass-forming melts

    Energy Technology Data Exchange (ETDEWEB)

    Orava, J.; Greer, A. L., E-mail: alg13@cam.ac.uk [WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan and Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge, Cambridge CB3 0FS (United Kingdom)

    2014-06-07

    Published values of crystal growth rates are compared for supercooled glass-forming liquids undergoing congruent freezing at a planar crystal-liquid interface. For the purposes of comparison pure metals are considered to be glass-forming systems, using data from molecular-dynamics simulations. For each system, the growth rate has a maximum value U{sub max} at a temperature T{sub max} that lies between the glass-transition temperature T{sub g} and the melting temperature T{sub m}. A classification is suggested, based on the lability (specifically, the propensity for fast crystallization), of the liquid. High-lability systems show “fast” growth characterized by a high U{sub max}, a low T{sub max} / T{sub m}, and a very broad peak in U vs. T / T{sub m}. In contrast, systems showing “slow” growth have a low U{sub max}, a high T{sub max} / T{sub m}, and a sharp peak in U vs. T / T{sub m}. Despite the difference of more than 11 orders of magnitude in U{sub max} seen in pure metals and in silica, the range of glass-forming systems surveyed fit into a common pattern in which the lability increases with lower reduced glass-transition temperature (T{sub g} / T{sub m}) and higher fragility of the liquid. A single parameter, a linear combination of T{sub g} / T{sub m} and fragility, can show a good correlation with U{sub max}. For all the systems, growth at U{sub max} is coupled to the atomic/molecular mobility in the liquid. It is found that, across the diversity of glass-forming systems, T{sub max} / T{sub g} = 1.48 ± 0.15.

  5. On correlated heterogeneities of glass-forming liquids

    CERN Document Server

    Bakai, A S

    2002-01-01

    The thermodynamics and structure of glass-forming liquids are considered within the framework of the heterophase fluctuation (HPF) model. The main goal of the theory developed is to fined for a description of the long-range correlations (LRC) of the density fluctuations known as the Fischer cluster. The van der Waals approximation of the HPF model shows that the liquid can have an isolated solid-fluid critical point analogous to the critical point of a gas-liquid system. Heterophase fluctuations in the form of solid like noncrystalline and fluid like clusters can have LRC in a narrow vicinity of the critical point. An analysis shows that the properties of the conventional critical fluctuations differ from those of the Fisher cluster. This forces one to look for another explanation of the observed LRC in glass-forming liquids. Large configurational entropy of liquids and glasses is a manifestation of multiplicity of the short-range ordering of molecules in the amorphous solid like and fluid like clusters. The ...

  6. Designing new biocompatible glass-forming Ti75-x Zr10 Nbx Si15 (x = 0, 15) alloys: corrosion, passivity, and apatite formation.

    Science.gov (United States)

    Abdi, Somayeh; Oswald, Steffen; Gostin, Petre Flaviu; Helth, Arne; Sort, Jordi; Baró, Maria Dolors; Calin, Mariana; Schultz, Ludwig; Eckert, Jürgen; Gebert, Annett

    2016-01-01

    Glass-forming Ti-based alloys are considered as potential new materials for implant applications. Ti75 Zr10 Si15 and Ti60 Zr10 Nb15 Si15 alloys (free of cytotoxic elements) can be produced as melt-spun ribbons with glassy matrix and embedded single β-type nanocrystals. The corrosion and passivation behavior of these alloys in their homogenized melt-spun states have been investigated in Ringer solution at 37°C in comparison to their cast multiphase crystalline counterparts and to cp-Ti and β-type Ti-40Nb. All tested materials showed very low corrosion rates as expressed in corrosion current densities icorr  new alloys passive states in a wide potential range. This corresponds to low passive current densities ipass  = 2 ± 1 µA/cm(2) based on the growth of oxide films with thickness d alloys is beneficial for stable surface passivity. The addition of Nb does not only improve the glass-forming ability and the mechanical properties but also supports a high pitting resistance even at extreme anodic polarization up to 4V versus SCE were oxide thickness values of d ∼35 nm are reached. With regard to the corrosion properties, the Nb-containing nearly single-phase glassy alloy can compete with the β-type Ti-40Nb alloy. SBF tests confirmed the ability for formation of hydroxyapatite on the melt-spun alloy surfaces. All these properties recommend the new glass-forming alloys for application as wear- and corrosion-resistant coating materials for implants. © 2015 Wiley Periodicals, Inc.

  7. Specific Abilities May Increment Psychometric g for High Ability Populations

    Science.gov (United States)

    2016-04-14

    1. REPORT DATE (DD-MM-YYYY) 04/2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) 04/2015 – 08/2016 4. TITLE AND SUBTITLE...higher ability groups. Intelligence, 23, 45-57. Lynn, R. (1990). Does Spearman’s g decline at high levels? Some evidence from Scotland . The Journal...1979). Use of the position analysis questionnaire for establishing the job component validity of tests. Journal of Applied Psychology, 64, 51

  8. Connection between fragility, mean-squared displacement and shear modulus in two van der Waals bonded glass-forming liquids

    DEFF Research Database (Denmark)

    Hansen, Henriette Wase; Frick, Bernhard; Hecksher, Tina

    2017-01-01

    The temperature dependence of the high-frequency shear modulus measured in the kHz range is compared with the mean-squared displacement measured in the nanosecond range for the two van der Waals bonded glass-forming liquids cumene and 5-polyphenyl ether. This provides an experimental test...

  9. High Ability Students' Voice on Learning Motivation

    Science.gov (United States)

    Garn, Alex C.; Jolly, Jennifer L.

    2014-01-01

    This study used a self-determination theory lens to investigate high ability learners' motivational experiences. Participants were 15 high ability youth involved in a summer learning camp for gifted students. Two major themes emerged from qualitative data analysis: (a) "The Fun Factor of Learning" and (b) "The Rewards and Pressures…

  10. Purpose in Life among High Ability Adolescents

    Science.gov (United States)

    Bronk, Kendall Cotton; Finch, W. Holmes; Talib, Tasneem L.

    2010-01-01

    Leading high ability scholars have proposed theories that suggest a purpose in life may be particularly prevalent among high ability youth; however, the prevalence of purpose has not been empirically assessed among this population. Therefore using in-depth interviews the present study established the prevalence of purpose among a sample of high…

  11. Magnetic Properties of Al-Gd-TM Glass-Forming Alloys

    Science.gov (United States)

    Uporov, Sergey; Estemirova, Svetlana; Bykov, Viktor; Mitrofanov, Valentin

    2016-01-01

    We report results of magnetic studies of glass-forming alloys with nominal composition of Al86Gd6TM8 (where TM = Cu, Ni, Co, Fe, Mn, Cr, Ti, Zr, Mo, Ta) synthesized by arc-melting. X-ray diffraction analysis and vibrating sample magnetometry were applied to characterize the prepared samples. All the alloys exhibit antiferromagnetic ordering at low temperatures. In some compositions, we observed metamagnetic transitions in external magnetic fields up to 3 T. Analysis of the paramagnetic susceptibility of the considered Al-Gd-TM systems has revealed non-magnetic behavior of the transition metals. We found that the magnetic properties of the studied samples can be described satisfactorily using only the Gd trivalent ions. But in some cases the magnetic moments of gadolinium are slightly larger than the theoretical values, probably, because of an additional contribution of the 5 d electrons. The obtained results are discussed in framework of the assumptions of the strong s- p- d hybridization and frustrated magnetic states of gadolinium. We argue that the hybridization might be one of the main factors improving the glass-forming ability in these ternary alloys.

  12. Distinguishability of particles in glass-forming systems

    Science.gov (United States)

    Mauro, John C.; Smedskjaer, Morten M.

    2012-11-01

    The distinguishability of particles has important implications for calculating the partition function in statistical mechanics. While there are standard formulations for systems of identical particles that are either fully distinguishable or fully indistinguishable, many realistic systems do not fall into either of these limiting cases. In particular, the glass transition involves a continuous transition from an ergodic liquid system of indistinguishable particles to a nonergodic glassy system where the particles become distinguishable. While the question of partial distinguishability of microstates has been treated previously in quantum information theory, this issue has not yet been addressed for a system of classical particles. In this paper, we present a general theoretical formalism for quantifying particle distinguishability in classical systems. This formalism is based on a classical definition of relative entropy, such as applied in quantum information theory. Example calculations for a simple glass-forming system demonstrate the continuous onset of distinguishability as temperature is lowered. We also examine the loss of distinguishability in the limit of long observation time, coinciding with the restoration of ergodicity. We discuss some of the general implications of our work, including the direct connection to topological constraint theory of glass. We also discuss qualitative features of distinguishability as they relate to the Second and Third Laws of thermodynamics.

  13. Fragility correlates thermodynamic and kinetic properties of glass forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, C.Narayana [Maharani’s Science College for Women, Bangalore 560001 (India); Viswanatha, R.; Chethana, B.K. [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India); Gowda, V.C.Veeranna [Government First Grade College, Jayanagara, Bangalore 560070 (India); Rao, K.J., E-mail: kalyajrao@yahoo.co.in [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 (India)

    2015-03-15

    Graphical abstract: The suggested new fragility parameter correlates viscosity and configurational entropy. - Highlights: • A new fragility function, F=ΔT/ΔC{sub p}×C{sub p}{sup l}/T{sub g} has been proposed. • A three parameter viscosity function using the new F reproduces Angell fragility plot. • A new ΔC{sub p} function is derived which directly relates Adam–Gibbs function with the fragility based viscosity function. - Abstract: In our earlier communication we proposed a simple fragility determining function, ([NBO]/V{sub m}{sup 3}T{sub g}), which we have now used to analyze several glass systems using available thermal data. A comparison with similar fragility determining function, ΔC{sub p}/C{sub p}{sup l}, introduced by Chryssikos et al. in their investigation of lithium borate glasses has also been performed and found to be more convenient quantity for discussing fragilities. We now propose a new function which uses both ΔC{sub p} and ΔT and which gives a numerical fragility parameter, F whose value lies between 0 and 1 for glass forming liquids. F can be calculated through the use of measured thermal parameters ΔC{sub p}, C{sub p}{sup l}, T{sub g} and T{sub m}. Use of the new fragility values in reduced viscosity equation reproduces the whole range of viscosity curves of the Angell plot. The reduced viscosity equation can be directly compared with the Adam–Gibbs viscosity equation and a heat capacity function can be formulated which reproduces satisfactorily the ΔC{sub p} versus ln(T{sub r}) curves and hence the configurational entropy.

  14. Creativity, synthetic intelligence and high ability

    Directory of Open Access Journals (Sweden)

    Marta Sainz

    2010-04-01

    Full Text Available The objective of this study is to analyze the construct of creativity and its relationship with high ability, presenting different definitions, assessment tools and strategies to encourage their development in the school context. The paper is structured into five sections: firstly, we define the concept of creativity. Secondly, we present the most relevant instruments used in the analysis of high ability students’ creativity. Thirdly, we look into several studies on creativity and high abilitiy, highlighting the main limitations of the research carried out. Fourthly, we present principles and strategies in order to foster creativity in the school context. Finally, some conclusions are drawn on the relationship between creativity and high ability.

  15. Extracurricular enrichment workshops for high ability students

    Directory of Open Access Journals (Sweden)

    Ángela Rojo

    2010-04-01

    Full Text Available The aim of this article is to analyze and explain attention to diversity measures for high ability (gifted and talented students. The model, developed in the Spanish region of Murcia, is based on cognitive psychology and aims to encourage thinking skills. The program is developed as a curriculum extension and the interests, motivations and abilities of children have been considered once these were identified. The article offers a theoretical approach, a set of objectives, and some of the activities that have been done with students.

  16. Determination of critical cooling rates in metallic glass forming alloy libraries through laser spike annealing.

    Science.gov (United States)

    Bordeenithikasem, Punnathat; Liu, Jingbei; Kube, Sebastian A; Li, Yanglin; Ma, Tianxing; Scanley, B Ellen; Broadbridge, Christine C; Vlassak, Joost J; Singer, Jonathan P; Schroers, Jan

    2017-08-02

    The glass forming ability (GFA) of metallic glasses (MGs) is quantified by the critical cooling rate (R C ). Despite its key role in MG research, experimental challenges have limited measured R C to a minute fraction of known glass formers. We present a combinatorial approach to directly measure R C for large compositional ranges. This is realized through the use of compositionally-graded alloy libraries, which were photo-thermally heated by scanning laser spike annealing of an absorbing layer, then melted and cooled at various rates. Coupled with X-ray diffraction mapping, GFA is determined from direct R C measurements. We exemplify this technique for the Au-Cu-Si system, where we identify Au 56 Cu 27 Si 17 as the alloy with the highest GFA. In general, this method enables measurements of R C over large compositional areas, which is powerful for materials discovery and, when correlating with chemistry and other properties, for a deeper understanding of MG formation.

  17. An Assessment of Binary Metallic Glasses: Correlations Between Structure, Glass Forming Ability and Stability (Preprint)

    Science.gov (United States)

    2011-07-01

    elements (Figure 2). Solutes or solvents are taken from alkaline earth metals, early and late transition metals, lanthanides and actinide elements...techniques such as scanning tunneling microscopy and 3D atom probe are suggested for future work. 4.2 Thermal Stability Parameters Give Post

  18. Glass-forming ability and rigidity percolation in SeTePb lone-pair semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Pankaj [Jaypee University of Information Technology, Department of Physics and Materials Science, Waknaghat, Solan, H.P. (India)

    2016-04-15

    Correlating the various physical parameters of known semiconductors and pointing the properties of new ones, a number of parameters have been employed recently with different levels of success. Taking this into account an attempt has been made to correlate the physical properties of Pb-doped Se-Te lone-pair semiconductors. The small band gap and large Bohr radius of lead (Pb) containing lone-pair semiconductors assist them with specific optical, electrical and thermal properties. The various physical parameters like number of constraints, lone pair of electron, heat of atomization, density, compactness, free volume percentage have been analyzed in terms of mean coordination number for (Se{sub 90}Te{sub 10}){sub 100-x} Pb{sub x} (x=0,4,8,12,16,20,24). The band gap for the compositions has been determined theoretically, and the obtained results are very well explained in terms of cohesive energy, electronegativity and average single bond energy. (orig.)

  19. PREFACE: Dynamic crossover phenomena in water and other glass-forming liquids Dynamic crossover phenomena in water and other glass-forming liquids

    Science.gov (United States)

    Chen, Sow-Hsin; Baglioni, Piero

    2012-02-01

    This special section has been inspired by the workshop on Dynamic Crossover Phenomena in Water and Other Glass-Forming Liquids, held during November 11-13, 2010 at Pensione Bencistà, Fiesole, Italy, a well-preserved 14th century Italian villa tucked high in the hills overlooking Florence. The meeting, an assembly of world renowned scientists, was organized as a special occasion to celebrate the 75th birthday of Professor Sow-Hsin Chen of MIT, a pioneer in several aspects of complex fluids and soft matter physics. The workshop covered a large variety of experimental and theoretical research topics of current interest related to dynamic crossover phenomena in water and, more generally, in other glass-forming liquids. The 30 invited speakers/lecturers and approximately 60 participants were a select group of prominent physicists and chemists from the USA, Europe, Asia and Mexico, who are actively working in the field. Some highlights of this special issue include the following works. Professor Yamaguchi's group and their collaborators present a neutron spin echo study of the coherent intermediate scattering function of heavy water confined in cylindrical pores of MCM-41-C10 silica material in the temperature range 190-298 K. They clearly show that a fragile-to-strong (FTS) dynamic crossover occurs at about 225 K. They attribute the FTS dynamic crossover to the formation of a tetrahedral-like structure, which is preserved in the bulk-like water confined to the central part of the cylindrical pores. Mamontov and Kolesnikov et al study the collective excitations in an aqueous solution of lithium chloride over a temperature range of 205-270 K using neutron and x-ray Rayleigh-Brillouin (coherent) scattering. They detect both the low-frequency and the high-frequency sounds known to exist in pure bulk water above the melting temperature. They also perform neutron (incoherent) and x-ray (coherent) elastic intensity scan measurements. Clear evidence of the crossover in the

  20. Cryomilling-induced solid dispersion of poor glass forming/poorly water-soluble mefenamic acid with polyvinylpyrrolidone K12.

    Science.gov (United States)

    Kang, Naewon; Lee, Jangmi; Choi, Ji Na; Mao, Chen; Lee, Eun Hee

    2015-06-01

    The effect of mechanical impact on the polymorphic transformation of mefenamic acid (MFA) and the formation of a solid dispersion of mefenamic acid, a poor glass forming/poorly-water soluble compound, with polyvinylpyrrolidone (PVP) K12 was investigated. The implication of solid dispersion formation on solubility enhancement of MFA, prepared by cryomilling, was investigated. Solid state characterization was conducted using powder X-ray diffraction (PXRD) and Fourier-transform infrared (FTIR) spectroscopy combined with crystal structure analysis. Apparent solubility of the mixtures in pH 7.4 buffer was measured. A calculation to compare the powder patterns and FTIR spectra of solid dispersions with the corresponding physical mixtures was conducted. Solid state characterization showed that (1) MFA I transformed to MFA II when pure MFA I was cryogenically milled (CM); and (2) MFA forms a solid dispersion when MFA was cryogenically milled with PVP K12. FTIR spectral analysis showed that hydrogen bonding facilitated by mechanical impact played a major role in forming solid dispersions. The apparent solubility of MFA was significantly improved by making a solid dispersion with PVP K12 via cryomilling. This study highlights the importance of cryomilling with a good hydrogen bond forming excipient as a technique to prepare solid dispersion, especially when a compound shows a poor glass forming ability and therefore, is not easy to form amorphous forms by conventional method.

  1. Measurements of the Poisson ratio and fragility of glass-forming liquids

    DEFF Research Database (Denmark)

    Christensen, Tage Emil; Olsen, Niels Boye

    Recently much attention has been given to models and phenomenology of glass-forming liquids that correlates fast and slow degrees of freedom . In particular the Poisson ratio has been correlated with fragility. We present data on shear - and bulk modulus obtained by the techniques of the piezoele......Recently much attention has been given to models and phenomenology of glass-forming liquids that correlates fast and slow degrees of freedom . In particular the Poisson ratio has been correlated with fragility. We present data on shear - and bulk modulus obtained by the techniques...... of the piezoelectric transducers PBG and PSG on a number of glass-forming liquids. Hereby the Poisson ratio can be found. Furthermore the PSG also gives the temperature dependence of shear viscosity and thereby the fragility. The validity of the conjectured relation is discussed...

  2. Energy Renormalization for Coarse-Graining the Dynamics of a Model Glass-Forming Liquid.

    Science.gov (United States)

    Xia, Wenjie; Song, Jake; Hansoge, Nitin K; Phelan, Frederick R; Keten, Sinan; Douglas, Jack F

    2018-02-15

    Coarse-grained modeling achieves the enhanced computational efficiency required to model glass-forming materials by integrating out "unessential" molecular degrees of freedom, but no effective temperature transferable coarse-graining method currently exists to capture dynamics. We address this fundamental problem through an energy-renormalization scheme, in conjunction with the localization model of relaxation relating the Debye-Waller factor ⟨u 2 ⟩ to the structural relaxation time τ. Taking ortho-terphenyl as a model small-molecule glass-forming liquid, we show that preserving ⟨u 2 ⟩ (at picosecond time scale) under coarse-graining by renormalizing the cohesive interaction strength allows for quantitative prediction of both short- and long-time dynamics covering the entire temperature range of glass formation. Our findings provide physical insights into the dynamics of cooled liquids and make progress for building temperature-transferable coarse-grained models that predict key properties of glass-forming materials.

  3. Morphological and structural study of gas atomized Zr-Cu-based glass-forming alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zambon, A.; Badan, B

    2004-07-15

    Zr-Cu-based glass-forming alloys were processed in a laboratory scale gas atomizer, operated in sonic conditions with nitrogen or helium as the atomizing medium. Powders of rather wide size distributions were obtained, in the under 212 {mu}m range, which afforded to carry out comparative phase analyses on particles which underwent quite different cooling conditions. X-ray diffraction examinations as well as light microscopy, transmission electron microscopy, differential thermal analysis (DTA) and microhardness determinations were used to investigate the powders belonging to different size ranges. Amorphous, partially crystalline and fully crystalline powders were obtained from each atomization batch. Light microscopy afforded to evaluate the morphometric details such as the secondary dendrite arm spacing in the crystalline particles, which were correlated with the estimated cooling rates computed by means of a simplified computer code. X-ray diffraction, TEM examinations and electron diffraction confirmed that conditions were established for the development of amorphous or nanocrystalline particles, in particular in the 'under 38 {mu}m' and in the 38-45 {mu}m size ranges. Microhardness determinations showed an extremely high hardness, of the order of 1000-1100 HV{sub 0.05} in the case of fully amorphous particles, which could be encountered mainly in the smaller size ranges, while in the case of crystalline powders the hardness was around a half of such value mainly in the larger, fully crystalline ones.

  4. Nanoscale physical properties of polymer glasses formed by solvent-assisted laser deposition

    Science.gov (United States)

    Shepard, Kimberly; Arnold, Craig; Priestley, Rodney

    2015-03-01

    High-energy, low-density nanostructured polymer glasses are formed via the solvent-assisted laser deposition technique MAPLE (Matrix Assisted Pulsed Laser Evaporation). During film deposition, micro- to nano-size polymer/solvent clusters are ejected via laser ablation from a frozen dilute polymer solution. During flight to the substrate under vacuum, the clusters experience rapid cooling and solvent stripping, forming polymer nanoglobules. Bulk polymer films are formed via the gradual assembly of these spherical-like nanostructured building blocks (i.e. nanoglobules). The MAPLE process thus enables investigation of the exceptional properties of glasses formed under extreme processing conditions. In the bulk state, we probe the effect of process parameters and chemical identity of the thermal behavior of a series of methacrylate polymers. We also employ multiple techniques to directly measure the properties of the polymer nanoglobules and connect the results to the global film properties. This talk will address nanoscale dilatometry via AFM, in which the volume of an individual polymer nanoglobule is tracked as it is heated through its glass transition, as well as Flash DSC analysis of the thermal properties of nanogram size MAPLE-deposited polymer glasses. We then discuss these findings in the context of the material's unconventional route to the glassy state.

  5. Structural origin of fractional Stokes-Einstein relation in glass-forming liquids

    Science.gov (United States)

    Pan, Shaopeng; Wu, Z. W.; Wang, W. H.; Li, M. Z.; Xu, Limei

    2017-01-01

    In many glass-forming liquids, fractional Stokes-Einstein relation (SER) is observed above the glass transition temperature. However, the origin of such phenomenon remains elusive. Using molecular dynamics simulations, we investigate the break- down of SER and the onset of fractional SER in a model of metallic glass-forming liquid. We find that SER breaks down when the size of the largest cluster consisting of trapped atoms starts to increase sharply at which the largest cluster spans half of the simulations box along one direction, and the fractional SER starts to follows when the largest cluster percolates the entire system and forms 3-dimentional network structures. Further analysis based on the percolation theory also confirms that percolation occurs at the onset of the fractional SER. Our results directly link the breakdown of the SER with structure inhomogeneity and onset of the fraction SER with percolation of largest clusters, thus provide a possible picture for the break- down of SER and onset of fractional SER in glass-forming liquids, which is is important for the understanding of the dynamic properties in glass-forming liquids.

  6. Source of non-arrhenius average relaxation time in glass-forming liquids

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    1998-01-01

    A major mystery of glass-forming liquids is the non-Arrhenius temperature-dependence of the average relaxation time. This paper briefly reviews the classical phenomenological models for non-Arrhenius behavior – the free volume model and the entropy model – and critiques against these models. We t...

  7. On the possible existence of crystallites in glass-forming liquids

    DEFF Research Database (Denmark)

    Dyre, Jeppe

    We speculate that glass-forming liquids may contain fairly large and well-defined crystallites. This is based on arguing that the slowly relaxing "frozen-in" stresses characterizing ultraviscous liquids increase the barrier for nucleation, thus allowing for larger unstable crystallites than other...

  8. Are the dynamics of silicate glasses and glass-forming liquids embedded in their elastic properties?

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.

    According to the elastic theory of the glass transition, the dynamics of glasses and glass-forming liquids are controlled by the evolution of shear modulus. In particular, the elastic shoving model expresses dynamics in terms of an activation energy required to shove aside the surrounding atoms, ...

  9. Exploring the Origin of Fragile-to-Strong Transition in Some Glass-Forming Liquids

    DEFF Research Database (Denmark)

    Yue, Yuanzheng; Hu, L. N.

    2014-01-01

    , topological and thermodynamic changes causing this transition. The theory for describing the transition has not been fully established. In this paper, we summarize our current understanding of the fragile-to-strong transition in some glass-forming liquids basedon our two published papers and recent...

  10. High Intellectual Ability: Extracurricular Enrichment and Cognitive Management

    Science.gov (United States)

    Sastre-Riba, Sylvia

    2013-01-01

    This study aims to provide a better understanding of high intellectual abilities and of how to address the educational needs of those who possess such abilities. Within the emergent paradigm, high intellectual abilities are understood as multidimensional and as the result of lifetime development; that is, not only are they the result of their…

  11. Dual field nonlinear dielectric spectroscopy in a glass forming EPON 828 epoxy resin

    Science.gov (United States)

    Rzoska, Sylwester J.; Drozd-Rzoska, Aleksandra

    2012-01-01

    Results of the dual field nonlinear dielectric spectroscopy (NDS) studies in supercooled glass forming epoxy resin EPON 828 are presented. For the NDS, changes of dielectric permittivity induced by DC (rectangular) or AC (sine-wave) pulses of a strong electric field were probed by a weak radio frequency electric field. A clear stretched exponential (x < 1) decay after switching off the DC pulse and a single exponential decay (x = 1) after switching off the AC pulse were found. The same results are presented for preliminary studies in superpressed low molecular glass former di-isobutyl phthalate. This observation may be considered as an argument for the heterogeneous picture of supercooled glass forming materials. The temperature dependences of the stationary responses related to DC and AC strong electric field excitations are also shown. The sensitivity of the applied set up made it possible to detect NDS outputs even for electric fields Estrong < 10 kV cm-1, qualitatively weaker than in similar ‘nonlinear, dielectric’ experimental studies on glass forming materials carried out so far.

  12. Translation-rotation decoupling of tracers of locally favorable structures in glass-forming liquids

    Science.gov (United States)

    Park, Yoonjae; Kim, Jeongmin; Sung, Bong June

    2017-09-01

    Particles in glass-forming liquids may form domains of locally favorable structures (LFSs) upon supercooling. Whether and how the LFS domains would relate to the slow relaxation of the glass-forming liquids have been issues of interest. In this study, we employ tracers of which structures resemble the LFS domains in Wahnström and Kob-Andersen (KA) glass-forming liquids and investigate the translation-rotation decoupling of the tracers. We find that the tracer structure affects how the translation and the rotation of tracers decouple and that information on the local mobility around the LFS domains may be gleaned from the tracer dynamics. According to the Stokes-Einstein relation and the Debye-Stokes-Einstein relation, the ratio of the translational (DT) and rotational (DR) diffusion coefficients is expected to be a constant over a range of T /η , where η and T denote the medium viscosity and temperature, respectively. In supercooled liquids and glasses, however, DT and DR decouple due to dynamic heterogeneity, thus DT/DR not being constant any more. In Wahnström glass-forming liquids, icosahedron LFS domains are the most long-lived ones and the mobility of neighbor particles around the icosahedron LFS domain is suppressed. We find from our simulations that the icosahedron tracers, similar in size and shape to the icosahedron LFS domains, experience drastic translation-rotation decoupling upon cooling. The local mobility of liquid particles around the icosahedron tracers is also suppressed significantly. On the other hand, tracers of FCC and HCP structures do not show translation-rotation decoupling in the Wahnström liquid. In KA glass-forming liquids, bicapped square antiprism LFS domains are the most long-lived LFS domains but are not correlated significantly with the local mobility. We find from our simulations that DT and DR of bicapped square antiprism tracers, also similar in size and shape to the bicapped square antiprism LFS domains, do not decouple

  13. Role of string-like collective atomic motion on diffusion and structural relaxation in glass forming Cu-Zr alloys

    Science.gov (United States)

    Zhang, Hao; Zhong, Cheng; Douglas, Jack F.; Wang, Xiaodong; Cao, Qingping; Zhang, Dongxian; Jiang, Jian-Zhong

    2015-04-01

    We investigate Cu-Zr liquid alloys using molecular dynamics simulation and well-accepted embedded atom method potentials over a wide range of chemical composition and temperature as model metallic glass-forming (GF) liquids. As with other types of GF materials, the dynamics of these complex liquids are characterized by "dynamic heterogeneity" in the form of transient polymeric clusters of highly mobile atoms that are composed in turn of atomic clusters exhibiting string-like cooperative motion. In accordance with the string model of relaxation, an extension of the Adam-Gibbs (AG) model, changes in the activation free energy ΔGa with temperature of both the Cu and Zr diffusion coefficients D, and the alpha structural relaxation time τα can be described to a good approximation by changes in the average string length, L. In particular, we confirm that the strings are a concrete realization of the abstract "cooperatively rearranging regions" of AG. We also find coexisting clusters of relatively "immobile" atoms that exhibit predominantly icosahedral local packing rather than the low symmetry packing of "mobile" atoms. These two distinct types of dynamic heterogeneity are then associated with different fluid structural states. Glass-forming liquids are thus analogous to polycrystalline materials where the icosahedrally packed regions correspond to crystal grains, and the strings reside in the relatively disordered grain boundary-like regions exterior to these locally well-ordered regions. A dynamic equilibrium between localized ("immobile") and wandering ("mobile") particles exists in the liquid so that the dynamic heterogeneity can be considered to be type of self-assembly process. We also characterize changes in the local atomic free volume in the course of string-like atomic motion to better understand the initiation and propagation of these fluid excitations.

  14. Crossover to potential energy landscape dominated dynamics in a model glass-forming liquid

    DEFF Research Database (Denmark)

    Schrøder, Thomas; Sastry, S.; Dyre, Jeppe

    2000-01-01

    An equilibrated model glass-forming liquid is studied by mapping successive configurations produced by molecular dynamics simulation onto a time series of inherent structures (local minima in the potential energy). Using this "inherent dynamics" approach we find direct numerical evidence...... for the long held view that below a crossover temperature, Tx, the liquid's dynamics can be separated into (i) vibrations around inherent structures and (ii) transitions between inherent structures [M. Goldstein, J. Chem. Phys. 51, 3728 (1969)], i.e., the dynamics become "dominated" by the potential energy...

  15. Stokes-Einstein relation in computer simulated bulk glass forming Cu33Zr67 melts

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiujun; Schober, Herbert [IFF, Forschungszentrum Juelich, 52425 Juelich (Germany)

    2009-07-01

    The validity of Stokes-Einstein (SE) relation in glass forming Cu33Zr67 melts is checked by studying the relationship between viscosity and self-diffusion coefficient with molecular dynamics simulation. The atomic interaction of Cu-Zr is modeled by modified-embedded-atomic method (MEAM). The self-diffusion coefficient is calculated from mean squared displacements (MSD) and the viscosity is evaluated from Green-Kubo equation. It was found that at temperatures higher than 1500K, SE relation is valid. When the temperature is further decreased, SE relation breaks down, which is an indication of dynamical heterogeneity in the melts.

  16. Fluctuations and Shape of Cooperative Rearranging Regions in Glass-Forming Liquids

    Directory of Open Access Journals (Sweden)

    Giulio Biroli

    2017-01-01

    Full Text Available We develop a theory of amorphous interfaces in glass-forming liquids. We show that the statistical properties of these surfaces, which separate regions characterized by different amorphous arrangements of particles, coincide with the ones of domain walls in the random field Ising model. A major consequence of our results is that supercooled liquids are characterized by two different static lengths: the point-to-set ξ_{PS}, which is a measure of the spatial extent of cooperative rearranging regions, and the wandering length ξ_{⊥}, which is related to the fluctuations of their shape. We find that ξ_{⊥} grows when approaching the glass transition but slower than ξ_{PS}. The wandering length increases as s_{c}^{-1/2}, where s_{c} is the configurational entropy. Our results strengthen the relationship with the random field Ising model found in recent works. They are in agreement with previous numerical studies of amorphous interfaces and provide a theoretical framework for explaining numerical and experimental findings on pinned particle systems and static lengths in glass-forming liquids.

  17. Desirable characteristics for teachers of High Ability/Gifted students

    Directory of Open Access Journals (Sweden)

    Alexandra da Costa Souza Martins

    2011-06-01

    Full Text Available This study investigated the desirable educational background for a teacher to work with high ability/gifted students, desirable characteristics these teachers should present and conceptions on high ability/giftedness. The participants were 20 public school teachers from a city surrounding Brasilia. Of this group, ten were elementary school teachers working with initial grades and ten were undergraduate Pedagogy teachers. A qualitative approach was used and data were collected by means of a semi-structured interview. A content analysis was then conducted. In relation to the desirable educational background for a teach of high ability/gifted students, participants indicated the need of continuous training, under graduation curriculum adapted to the theme and graduation courses in the area. The desirable features for teachers of high ability/gifted students were related to personological attributes (personality traits and intellectual ability, as well as professional characteristics. The conceptions on high ability/giftedness presented by the participants were, in general, close to those found in the literature and used as reference for this study. However, there was lack of information on how to apply the theory into real practice, as well as several wrong ideas on the topic.

  18. Crystallization and vitrification of electrons in a glass-forming charge liquid

    Science.gov (United States)

    Sasaki, S.; Hashimoto, K.; Kobayashi, R.; Itoh, K.; Iguchi, S.; Nishio, Y.; Ikemoto, Y.; Moriwaki, T.; Yoneyama, N.; Watanabe, M.; Ueda, A.; Mori, H.; Kobayashi, K.; Kumai, R.; Murakami, Y.; Müller, J.; Sasaki, T.

    2017-09-01

    Charge ordering (CO) is a phenomenon in which electrons in solids crystallize into a periodic pattern of charge-rich and charge-poor sites owing to strong electron correlations. This usually results in long-range order. In geometrically frustrated systems, however, a glassy electronic state without long-range CO has been observed. We found that a charge-ordered organic material with an isosceles triangular lattice shows charge dynamics associated with crystallization and vitrification of electrons, which can be understood in the context of an energy landscape arising from the degeneracy of various CO patterns. The dynamics suggest that the same nucleation and growth processes that characterize conventional glass-forming liquids guide the crystallization of electrons. These similarities may provide insight into our understanding of the liquid-glass transition.

  19. Anisotropic spatially heterogeneous dynamics in a model glass-forming binary mixture

    Energy Technology Data Exchange (ETDEWEB)

    Flenner, Elijah; Szamel, Grzegorz [Department of Chemistry, Colorado State University, Fort Collins, CO 80523 (United States)

    2007-05-23

    We calculated a four-point correlation function G{sub 4}(k,r;t) and the corresponding structure factor S{sub 4}(k,q;t) for a model glass-forming binary mixture. These functions measure the spatial correlations of the relaxation of different particles. We found that these four-point functions are anisotropic and depend on the angle between vectors k and r (or q). The anisotropy is the strongest for times somewhat longer than the {beta} relaxation time, but it is quite pronounced even for times comparable to the {alpha} relaxation time, {tau}{sub {alpha}}. At the lowest temperatures S{sub 4}(k,q;{tau}{sub {alpha}} is strongly anisotropic even for the smallest wavevector q accessible in our simulation.

  20. Localized Excitations and the Morphology of Cooperatively Rearranging Regions in a Colloidal Glass-Forming Liquid

    Science.gov (United States)

    Gokhale, Shreyas; Ganapathy, Rajesh; Nagamanasa, K. Hima; Sood, A. K.

    2016-02-01

    We develop a scheme based on a real space microscopic analysis of particle dynamics to ascertain the relevance of dynamical facilitation as a mechanism of structural relaxation in glass-forming liquids. By analyzing the spatial organization of localized excitations within clusters of mobile particles in a colloidal glass former and examining their partitioning into shell-like and corelike regions, we establish the existence of a crossover from a facilitation-dominated regime at low area fractions to a collective activated hopping-dominated one close to the glass transition. This crossover occurs in the vicinity of the area fraction at which the peak of the mobility transfer function exhibits a maximum and the morphology of cooperatively rearranging regions changes from stringlike to a compact form. Collectively, our findings suggest that dynamical facilitation is dominated by collective hopping close to the glass transition, thereby constituting a crucial step towards identifying the correct theoretical scenario for glass formation.

  1. Simple Theory for the Dynamics of Mean-Field-Like Models of Glass-Forming Fluids

    Science.gov (United States)

    Szamel, Grzegorz

    2017-10-01

    We propose a simple theory for the dynamics of model glass-forming fluids, which should be solvable using a mean-field-like approach. The theory is based on transparent physical assumptions, which can be tested in computer simulations. The theory predicts an ergodicity-breaking transition that is identical to the so-called dynamic transition predicted within the replica approach. Thus, it can provide the missing dynamic component of the random first order transition framework. In the large-dimensional limit the theory reproduces the result of a recent exact calculation of Maimbourg et al. [Phys. Rev. Lett. 116, 015902 (2016), 10.1103/PhysRevLett.116.015902]. Our approach provides an alternative, physically motivated derivation of this result.

  2. Dielectric relaxation of long-chain glass-forming monohydroxy alcohols

    Science.gov (United States)

    Gao, Yanqin; Tu, Wenkang; Chen, Zeming; Tian, Yongjun; Liu, Riping; Wang, Li-Min

    2013-10-01

    The dielectric relaxation of two long-chain glass forming monohydroxy alcohols, 2-butyl-1-octanol and 2-hexyl-1-decanol, is studied at low temperature. Remarkable broadening from the pure Debye relaxation is identified for the slowest dynamics, differing from the dielectric spectra of short-chain alcohols. The broadening of the Debye-like relaxation in the two liquids develops as temperature increases, and the approaching of the Debye-like and structural relaxation widths is shown. Similar results are observed in the dielectric spectra of dilute 2-ethyl-1-hexanol in either 2-hexyl-1-decanol or squalane. The results of the liquids and mixtures reveal a correlation between the broadening and the Debye-like relaxation strength. Molecular associations in monohydroxy alcohols are discussed with the modification of the Debye relaxation.

  3. Ioffe-Regel localization of longitudinal acoustic excitations and the Arrhenius crossover regime in glass-forming metallic liquids

    Science.gov (United States)

    Jaiswal, Abhishek; Zhang, Yang

    The Ioffe-Regel (IR) criterion is known to distinguish the boundary between propagating and localized excitations. In previous studies of liquids the localization of transverse excitations within atomic cages at high-temperature has been elucidated using the IR limit. Much less emphasis has been put on the nature of longitudinal excitations and the IR limit. Herein, we map out the wavelength dependent IR crossover temperature of the longitudinal excitations in an excellent Cu-Zr-Al based glass-former. We find that the inflection point of this map occurs at the Arrhenius crossover temperature TA identified from deviations of Arrhenius form in transport properties and the breakdown of Stokes-Einstein relation. The corresponding wavelength of longitudinal excitations at TA equals the limit where all partial pair distribution functions g (r) of the liquid approaches the random structure limit, essentially marking the boundary between the discrete and the continuous liquid. This map allows us to extract a temperature range for the Arrhenius crossover or the landscape-influenced regime in a glass-forming liquid.

  4. Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys.

    Science.gov (United States)

    Sopha, Hanna; Pohl, Darius; Damm, Christine; Hromadko, Ludek; Rellinghaus, Bernd; Gebert, Annett; Macak, Jan M

    2017-01-01

    In this work, we report for the first time on the use of melt spun glass-forming alloys - Ti75Zr10Si15 (TZS) and Ti60Zr10Si15Nb15 (TZSN) - as substrates for the growth of anodic oxide nanotube layers. Upon their anodization in ethylene glycol based electrolytes, highly ordered nanotube layers were achieved. In comparison to TiO2 nanotube layers grown on Ti foils, under the same conditions for reference, smaller diameter nanotubes (~116nm for TZS and ~90nm for TZSN) and shorter nanotubes (~11.5μm and ~6.5μm for TZS and TZSN, respectively) were obtained for both amorphous alloys. Furthermore, TEM and STEM studies, coupled with EDX analysis, revealed a double-wall structure of the as-grown amorphous oxide nanotubes with Ti species being enriched in the inner wall, and Si species in the outer wall, whereby Zr and Nb species were homogeneously distributed. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Crystal growth nucleation and Fermi energy equalization of intrinsic spherical nuclei in glass-forming melts

    Directory of Open Access Journals (Sweden)

    Robert F Tournier

    2009-01-01

    Full Text Available The energy saving resulting from the equalization of Fermi energies of a crystal and its melt is added to the Gibbs free-energy change ΔG2ls associated with a crystal formation in glass-forming melts. This negative contribution being a fraction ε ls(T of the fusion heat is created by the electrostatic potential energy −U0 resulting from the electron transfer from the crystal to the melt and is maximum at the melting temperature Tm in agreement with a thermodynamics constraint. The homogeneous nucleation critical temperature T2, the nucleation critical barrier ΔG2ls*/kBT and the critical radius R*2ls are determined as functions of εls(T. In bulk metallic glass forming melts, εls(T and T2 only depend on the free-volume disappearance temperature T0l, and εls(Tm is larger than 1 (T0l>Tm/3; in conventional undercooled melts εls(Tm is smaller than 1 (T0l>Tm/3. Unmelted intrinsic crystals act as growth nuclei reducing ΔG2ls*/kBT and the nucleation time. The temperature-time transformation diagrams of Mg65Y10 Cu25, Zr41.2Ti13.8 Cu12.5Ni10Be22.5, Pd43Cu27 Ni10P20, Fe83B17 and Ni melts are predicted using classic nucleation models including time lags in transient nucleation, by varying the intrinsic nucleus contribution to the reduction of ΔG2ls*/kBT. The energy-saving coefficient ε nm(T of an unmelted crystal of radius Rnm is reduced when Rnm LtR*2ls; εnm is quantified and corresponds to the first energy level of one s-electron moving in vacuum in the same spherical attractive potential −U0 despite the fact that the charge screening is built by many-body effects.

  6. [Psychoeducational intervention in high ability: intellectual functioning and extracurricular enrichment].

    Science.gov (United States)

    Sastre-Riba, Sylvia

    2014-02-24

    The 'new paradigm' defines the high intellectual ability as a potential that should crystallize progressively throughout development. Its main feature is a high intellectual initial multidimensional potential, which is transformed so that, being a person with high intellectual ability is the result of a developmental process from a neurobiological substrate and the incidence of variables (psychosocial and education) which determines its manifestation more or less stable and optimal to excellence. It is interesting to know the effectiveness of psychoeducational intervention of the extracurricular enrichment programs and their effects on the expression of differential functioning and the optimization of the management of cognitive resources that lead to excellence. An extracurricular enrichment program is described and evaluated through: 1) the stability of the intellectual measures; 2) the satisfaction level of participants and families. Participants are 58 high ability students on the enrichment program and 25 parents. Intellectual profiles are obtained on T1-T2 and calculated their stability by regression analysis, the CSA and CSA-P questionnaires were applied in order to know the participants and families' satisfaction measure. Results show the basic stability of intellectual profiles with five cases of instability among the 58 profiles obtained, and a high satisfaction with the results obtained in the domain of cognitive and personal management among the participants.

  7. Role of structure in the α and β dynamics of a simple glass-forming liquid

    Science.gov (United States)

    Fragiadakis, D.; Roland, C. M.

    2017-02-01

    The elusive connection between dynamics and local structure in supercooled liquids is an important piece of the puzzle in the unsolved problem of the glass transition. The Johari-Goldstein β relaxation, ubiquitous in glass-forming liquids, exhibits mean properties that are strongly correlated to the long-time α dynamics. However, the former comprises simpler, more localized motion, and thus has perhaps a more straightforward connection to structure. Molecular dynamics simulations were carried out on a two-dimensional, rigid diatomic molecule (the simplest structure exhibiting a distinct β process) to assess the role of the local liquid structure on both the Johari-Goldstein β and the α relaxation. Although the average properties for these two relaxations are correlated, there is no connection between the β and α properties of a given (single) molecule. The propensity for motion at long times is independent of the rate or strength of a molecule's β relaxation. The mobility of a molecule averaged over many initial energies, a measure of the influence of structure, was found to be heterogeneous, with clustering at both the β and α time scales. This heterogeneity is less extended spatially for the β than for the α dynamics, as expected; however, the local structure is the more dominant control parameter for the β process. In the glassy state, the arrangement of neighboring molecules determines entirely the relaxation properties, with no discernible effect from the particle momenta.

  8. Pressure effects on structure and dynamics of metallic glass-forming liquid

    Science.gov (United States)

    Hu, Yuan-Chao; Guan, Peng-Fei; Wang, Qing; Yang, Yong; Bai, Hai-Yang; Wang, Wei-Hua

    2017-01-01

    Although the structure and dynamics of metallic glass-forming liquids have been extensively investigated, studies of the pressure effects are rare. In the present study, the structural and dynamical properties of a ternary metallic liquid are systematically studied via extensive molecular dynamics simulations. Our results clearly show that, like isobaric cooling, isothermal compression could also slow down the dynamics of metallic liquid, leading to glass formation. However, the temperature- and pressure-induced glass transitions differ in the formation of local coordination structures and the variation of fragility. The increase of the kinetic fragility with increasing pressure is also accompanied by a monotonic structural fragility change. These findings may suggest a link between dynamics and structure. In addition, with increasing pressure, the dynamics becomes more heterogeneous, as revealed by the non-Gaussian parameter and dynamic correlation length. Here the length scales of both slow and fast domains are examined and discussed by analyzing the four-point dynamic structure factor associated with spatial correlations of atomic mobility. These correlation lengths coexist in the metallic liquids and grow comparatively in the considered temperature and pressure ranges. Finally, the scaling relation between the relaxation times and correlation lengths is discussed, which is found to be consistent with the spirit of Adam-Gibbs and random first-order transition theories.

  9. Relaxation transition in glass-forming polybutadiene as revealed by nuclear resonance X-ray scattering.

    Science.gov (United States)

    Kanaya, Toshiji; Inoue, Rintaro; Saito, Makina; Seto, Makoto; Yoda, Yoshitaka

    2014-04-14

    We investigated the arrest mechanism of molecular motions in a glass forming polybutadiene near the glass transition using a new nuclear resonance synchrotron X-ray scattering technique to cover a wide time range (10(-9) to 10(-5) s) and a scattering vector Q range (9.6-40 nm(-1)), which have never been accessed by other methods. Owing to the wide time and Q ranges it was found for the first time that a transition of the α-process to the slow β-process (or the Johari-Goldstein process) was observed in a Q range higher than the first peak in the structure factor S(Q) at the critical temperature T(c) in the mode coupling theory. The results suggest the important roles of hopping motions below T(c), which was predicted by the recent extended mode coupling theory and the cooperative motions due to the strong correlation at the first peak in S(Q) in the arrest mechanism.

  10. Efficient measurement of point-to-set correlations and overlap fluctuations in glass-forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Berthier, Ludovic [Laboratoire Charles Coulomb, UMR 5221 CNRS and Université de Montpellier, Montpellier (France); Charbonneau, Patrick [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Yaida, Sho, E-mail: sho.yaida@duke.edu [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States)

    2016-01-14

    Cavity point-to-set correlations are real-space tools to detect the roughening of the free-energy landscape that accompanies the dynamical slowdown of glass-forming liquids. Measuring these correlations in model glass formers remains, however, a major computational challenge. Here, we develop a general parallel-tempering method that provides orders-of-magnitude improvement for sampling and equilibrating configurations within cavities. We apply this improved scheme to the canonical Kob-Andersen binary Lennard-Jones model for temperatures down to the mode-coupling theory crossover. Most significant improvements are noted for small cavities, which have thus far been the most difficult to study. This methodological advance also enables us to study a broader range of physical observables associated with thermodynamic fluctuations. We measure the probability distribution of overlap fluctuations in cavities, which displays a non-trivial temperature evolution. The corresponding overlap susceptibility is found to provide a robust quantitative estimate of the point-to-set length scale requiring no fitting. By resolving spatial fluctuations of the overlap in the cavity, we also obtain quantitative information about the geometry of overlap fluctuations. We can thus examine in detail how the penetration length as well as its fluctuations evolve with temperature and cavity size.

  11. Fractional Viscosity Dependence of Reaction Kinetics in Glass-Forming Liquids

    Science.gov (United States)

    Kwon, Seulki; Cho, Hyun Woo; Kim, Jeongmin; Sung, Bong June

    2017-08-01

    The diffusion of molecules in complex systems such as glasses and cell cytoplasm is slow, heterogeneous, and sometimes nonergodic. The effects of such intriguing diffusion on the kinetics of chemical and biological reactions remain elusive. In this Letter, we report that the kinetics of the polymer loop formation reaction in a Kob-Andersen (KA) glass forming liquid is influenced significantly by the dynamic heterogeneity. The diffusion coefficient D of a KA liquid deviates from the Stokes-Einstein relation at low temperatures and D shows a fractional dependence on the solvent viscosity ηs, i.e., D ˜ηs-ξD with ξD=0.85 . The dynamic heterogeneity of a KA liquid affects the rate constant krxn of the loop formation and leads to the identical fractional dependence of krxn on ηs with krxn˜ηs-ξ and ξ =ξD, contrary to reactions in dynamically homogeneous solutions where krxn˜ηs-1.

  12. [High ability children and their differential cognitive functioning].

    Science.gov (United States)

    Sastre-Riba, S

    2008-01-01

    From the neuroconstructivist point of view, cognitive development is understood as a process of successive and continuous reorganization whose changing mechanisms and differential outcomes (typical and atypical) must be studied. High intellectual abilities are one of their differential manifestations but its concept and nature is confused conditioning the validity of its identification and the efficacy of the interventional programs. To propose a clarifying definition of the nature of high intellectual abilities and their manifestations: giftedness, talent and genious, as well as their cognitive functioning and neurological correlates. A qualitative task analysis is applied to 41 participants with intellectual profiles corresponding to: giftedness, talent and typical intelligence, previously obtained. Results show differences on the cognitive results, not only referred to the quantity of informations produced but in the data organization more complex and hard interrelated among the gifted participants. It must be a differential process of resolution adjusted to each one of the profiles studied.

  13. Communication: High pressure specific heat spectroscopy reveals simple relaxation behavior of glass forming molecular liquid

    DEFF Research Database (Denmark)

    Roed, Lisa Anita; Niss, Kristine; Jakobsen, Bo

    2015-01-01

    liquids in which different physical relaxation processes are both as function of temperature and pressure/density governed by the same underlying “inner clock.” Furthermore, the results are discussed in terms of the recent conjecture that van der Waals liquids, like the measuredliquid, comply...

  14. Growing correlation length on cooling below the onset of caging in a simulated glass-forming liquid

    DEFF Research Database (Denmark)

    Lačević, N.; Starr, F. W.; Schrøder, Thomas

    2002-01-01

    We present a calculation of a fourth-order, time-dependent density correlation function that measures higher-order spatiotemporal correlations of the density of a liquid. From molecular dynamics simulations of a glass-forming Lennard-Jones liquid, we find that the characteristic length scale...... of the dynamics of the liquid in the alpha-relaxation regime....

  15. Anomalous Crystallization as a Signature of the Fragile-to-Strong Transition in Metallic Glass-Forming Liquids

    DEFF Research Database (Denmark)

    Yang, X.N.; Zhou, C.; Sun, Q.J.

    2014-01-01

    We study the fragile-to-strong (F−S) transition of metallic glass-forming liquids (MGFLs) by measuring the thermal response during annealing and dynamic heating of La55Al25Ni5Cu15 glass ribbons fabricated at different cooling rates. We find that the glasses fabricated in the intermediate regime...

  16. Identifying high ability students: a contribution from neuropsychological indicators

    Directory of Open Access Journals (Sweden)

    Dora Cortat Simonetti

    2010-06-01

    Full Text Available This paper presents some data on the convergence between psychometric intelligence measurements (IQ tests and physiological signs of mental activity found in high ability adolescents. The research study focus on a small group of 15 subjects submitted to electric encephalograms, previously chosen from a larger group of 77 classmates on the basis of scores on the WISC-III IQ Test. The results suggest continuous predominance of Alpha waves for the gifted group (higher frequency percentile and higher amplitude what was not observed in the group without any superior intellectual ability. Even taking into account methodological limitations, this study may contribute to the understanding of a relationship between the intellectual quotient (IQ and alpha waves frequency and amplitude, as observed during performance on cognitive tasks. Such results may suggest a possibility to complement psychometric measures with encephalic registers in giftedness research studies.

  17. Microscopic relaxations in a protein sustained down to 160K in a non-glass forming organic solvent.

    Science.gov (United States)

    Mamontov, E; O'Neill, H

    2017-01-01

    We have studied microscopic dynamics of a protein in carbon disulfide, a non-glass forming solvent, down to its freezing temperature of ca. 160K. We have utilized quasielastic neutron scattering. A comparison of lysozyme hydrated with water and dissolved in carbon disulfide reveals a stark difference in the temperature dependence of the protein's microscopic relaxation dynamics induced by the solvent. In the case of hydration water, the common protein glass-forming solvent, the protein relaxation slows down in response to a large increase in the water viscosity on cooling down, exhibiting a well-known protein dynamical transition. The dynamical transition disappears in non-glass forming carbon disulfide, whose viscosity remains a weak function of temperature all the way down to freezing at just below 160K. The microscopic relaxation dynamics of lysozyme dissolved in carbon disulfide is sustained down to the freezing temperature of its solvent at a rate similar to that measured at ambient temperature. Our results demonstrate that protein dynamical transition is not merely solvent-assisted, but rather solvent-induced, or, more precisely, is a reflection of the temperature dependence of the solvent's glass-forming dynamics. We hypothesize that, if the long debated idea regarding the direct link between the microscopic relaxations and the biological activity in proteins is correct, then not only the microscopic relaxations, but also the activity, could be sustained in proteins all the way down to the freezing temperature of a non-glass forming solvent with a weak temperature dependence of its viscosity. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effect of component substitution on the atomic dynamics in glass-forming binary metallic melts

    Science.gov (United States)

    Nowak, B.; Holland-Moritz, D.; Yang, F.; Voigtmann, Th.; Evenson, Z.; Hansen, T. C.; Meyer, A.

    2017-08-01

    We investigate the substitution of early transition metals (Zr, Hf, and Nb) in Ni-based binary glass-forming metallic melts and the impact on structural and dynamical properties by using a combination of neutron scattering, electrostatic levitation (ESL), and isotopic substitution. The self-diffusion coefficients measured by quasielastic neutron scattering (QENS) identify a sluggish diffusion as well as an increased activation energy by almost a factor of 2 for Hf35Ni65 compared to Zr36Ni64 . This finding can be explained by the locally higher packing density of Hf atoms in Hf35Ni65 compared to Zr atoms in Zr36Ni64 , which has been derived from interatomic distances by analyzing the measured partial structure factors. Furthermore, QENS measurements of liquid Hf35Ni65 prepared with 60Ni , which has a vanishing incoherent scattering cross section, have demonstrated that self-diffusion of Hf is slowed down compared to the concentration weighted self-diffusion of Hf and Ni. This implies a dynamical decoupling between larger Hf and smaller Ni atoms, which can be related to a saturation effect of unequal atomic nearest-neighbor pairs, that was observed recently for Ni-rich compositions in Zr-Ni metallic melts. In order to establish a structure-dynamics relation, measured partial structure factors have been used as an input for mode-coupling theory (MCT) of the glass transition to calculate self-diffusion coefficients for the different atomic components. Remarkably, MCT can reproduce the increased activation energy for Hf35Ni65 as well as the dynamical decoupling between Hf and Ni atoms.

  19. Crystal growth nucleation and equalization of Fermi energies of intrinsic nuclei and glass-forming melts

    Energy Technology Data Exchange (ETDEWEB)

    Tournier, Robert F, E-mail: Robert.Tournier@grenoble.cnrs.f [Centre National de la Recherche Scientifique, Consortium de Recherches pour l' Emergence de Technologies Avancees, B.P. 166, 38042-Grenoble Cedex 09 (France)

    2009-01-01

    The energy saving produced by the equalization of Fermi energies of a crystal and its melt is determined by adding a negative fraction epsilon{sub sl}(T) of the fusion heat to the Gibbs free energy change DELTAG{sub 2ls} associated to a charged crystal formation in glass-forming melts. In bulk metallic glasses, epsilon{sub ls}(T{sub m}) is larger than 1 at the melting temperature T{sub m} and only determined by the knowledge of the free volume disappearance temperature. When the unmelted intrinsic crystals have a radius R{sub nm} much smaller than the critical radius R*{sub 2ls}, epsilon{sub sl}(T) is strongly reduced by the quantification of electronic levels in the large electrostatic potential created by the electron transfer from the crystal to the melt. The reduced value epsilon{sub nm0} of epsilon{sub sl}(T{sub m}) for R{sub nm}=3.2E-10m in Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} is determined by comparing the experimental Time-Temperature-Transformation diagram measured by electrostatic levitation to the calculated one. It exactly corresponds to the first energy level of one s state electron moving in the same spherical attractive potential and in vacuum in spite of the fact that, in a metal, the charge screening is built by many-body effects.

  20. Pair dynamics in a glass-forming binary mixture: Simulations and theory

    Science.gov (United States)

    Murarka, Rajesh K.; Bagchi, Biman

    2003-04-01

    We have carried out molecular dynamics simulations to understand the dynamics of a tagged pair of atoms in a strongly nonideal glass-forming binary Lennard-Jones mixture. Here atom B is smaller than atom A (σBB=0.88σAA, where σAA is the molecular diameter of the A particles) and the AB interaction is stronger than that given by Lorentz-Berthelot mixing rule (ɛAB=1.5ɛAA, where ɛAA is the interaction energy strength between the A particles). The generalized time-dependent pair distribution function is calculated separately for the three pairs (AA, BB, and AB). The three pairs are found to behave differently. The relative diffusion constants are found to vary in the order DBBR>DABR>DAAR, with DBBR≃2DAAR, showing the importance of the hopping process (B hops much more than A). We introduce a non-Gaussian parameter [αP2(t)] to monitor the relative motion of a pair of atoms and evaluate it for all the three pairs with initial separations chosen to be at the first peak of the corresponding partial radial distribution functions. At intermediate times, significant deviation from the Gaussian behavior of the pair distribution functions is observed with different degrees for the three pairs. A simple mean-field (MF) model, proposed originally by Haan [Phys. Rev. A 20, 2516 (1979)] for one-component liquid, is applied to the case of a binary mixture and compared with the simulation results. While the MF model successfully describes the dynamics of the AA and AB pairs, the agreement for the BB pair is less satisfactory. This is attributed to the large scale anharmonic motions of the B particles in a weak effective potential. Dynamics of the next nearest neighbor pairs is also investigated.

  1. Structural evolution during fragile-to-strong transition in CuZr(Al) glass-forming liquids

    DEFF Research Database (Denmark)

    Zhou, C.; Hu, L.N.; Sun, Q.J.

    2015-01-01

    In the present work, we show experimental evidence for the dynamic fragile-to-strong (F-S) transition in a series of CuZr(Al) glass-forming liquids (GFLs). A detailed analysis of the dynamics of 98 glass-forming liquids indicates that the F-S transition occurs around Tf-s ≈ 1.36 Tg. Using...... the hyperquenching-annealing-x-ray scattering approach, we have observed a three-stage evolution pattern of medium-range ordering (MRO) structures during the F-S transition, indicating a dramatic change of the MRO clusters around Tf-s upon cooling. The F-S transition in CuZr(Al) GFLs is attributed to the competition...... among the MRO clusters composed of different locally ordering configurations. A phenomenological scenario has been proposed to explain the structural evolution from the fragile to the strong phase in the CuZr(Al) GFLs....

  2. How closely do many-body potentials describe the structure and dynamics of Cu-Zr glass-forming alloy?

    Science.gov (United States)

    Lad, K. N.; Jakse, N.; Pasturel, A.

    2017-03-01

    Molecular dynamics investigations of the structure and dynamics of Cu64.5Zr35.5 metallic glass-forming alloy have been carried out using five different semi-empirical, many-body interaction potentials based on the Finnis-Sinclair model [M. I. Mendelev et al., J. Appl. Phys. 102, 043501 (2007) (MSK); M. I. Mendelev et al., Philos. Mag. 89, 967 (2009) (MKOSYP); L. Ward et al., e-print arXiv:1209.0619 (2012) (WAFW)] and the embedded-atom model [Y. Q. Cheng et al., Phys. Rev. Lett. 102, 245501 (2009) (CMS) and N. Jakse et al., Phys. Rev. B 85, 174201 (2012) (JNP)]. Although the total static structure factor of the alloy for all the five interaction potentials is, in general, found to be in good agreement with the experimental results, the investigation of a local structure in terms of icosahedral short-range order reveals that the effect of the interaction potential (especially the cohesive part) on the structure of the alloy is not as trivial as it seems. For MSK and JNP potentials, the self-intermediate scattering function Fs(q, t), q-dependence of the structural relaxation time τα in the low-q region, and the self-diffusion coefficient, Ds, for Cu-atoms in the alloy are in excellent agreement with the experimental results. The results for MKOSYP, CMS, and WAFW potentials deviate significantly from the experiment and suggest the dynamics of the alloy to be faster. The difference in the description of the dynamics of the alloy by different potentials is found to be due to the difference in the relevant energy scales corresponding to the temperature scales. τα and Ds exhibit Arrhenius temperature dependence in the high temperature regime above the melting temperature. We also suggest that the attractive forces influence the dynamics of the liquid alloy significantly, which is against the mere perturbative role assigned to the attractive forces in the van der Waals picture of liquids that has been challenged in the recent years. As the five interaction potentials

  3. A successful intervention program for high ability minority students

    Science.gov (United States)

    Coleman, Winson R.

    1989-01-01

    intervention program is the Saturday Academy program for high ability minority students in the Washington, D.C. area. A description of the Saturday Academy is provided with the intent of making it available to personnel who are considering the development of similar projects. The effect of participation in the program on high school graduate rates, college enrollment, and choice of quantitative major is examined.

  4. Parenting Style, Perfectionism, and Creativity in High-Ability and High-Achieving Young Adults

    Science.gov (United States)

    Miller, Angie L.; Lambert, Amber D.; Speirs Neumeister, Kristie L.

    2012-01-01

    The current study explores the potential relationships among perceived parenting style, perfectionism, and creativity in a high-ability and high-achieving young adult population. Using data from 323 honors college students at a Midwestern university, bivariate correlations suggested positive relationships between (a) permissive parenting style and…

  5. Kissinger method applied to the crystallization of glass-forming liquids: Regimes revealed by ultra-fast-heating calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Orava, J., E-mail: jo316@cam.ac.uk [Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Greer, A.L., E-mail: alg13@cam.ac.uk [Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2015-03-10

    Highlights: • Study of ultra-fast DSC applied to the crystallization of glass-forming liquids. • Numerical modeling of DSC traces at heating rates exceeding 10 orders of magnitude. • Identification of three regimes in Kissinger plots. • Elucidation of the effect of liquid fragility on the Kissinger method. • Modeling to study the regime in which crystal growth is thermodynamically limited. - Abstract: Numerical simulation of DSC traces is used to study the validity and limitations of the Kissinger method for determining the temperature dependence of the crystal-growth rate on continuous heating of glasses from the glass transition to the melting temperature. A particular interest is to use the wide range of heating rates accessible with ultra-fast DSC to study systems such as the chalcogenide Ge{sub 2}Sb{sub 2}Te{sub 5} for which fast crystallization is of practical interest in phase-change memory. Kissinger plots are found to show three regimes: (i) at low heating rates the plot is straight, (ii) at medium heating rates the plot is curved as expected from the liquid fragility, and (iii) at the highest heating rates the crystallization rate is thermodynamically limited, and the plot has curvature of the opposite sign. The relative importance of these regimes is identified for different glass-forming systems, considered in terms of the liquid fragility and the reduced glass-transition temperature. The extraction of quantitative information on fundamental crystallization kinetics from Kissinger plots is discussed.

  6. Decoupling of component diffusivities in glass-forming Zr-Ni-Ti-Cu-Be alloys above the melting temperature

    Energy Technology Data Exchange (ETDEWEB)

    Basuki, Sri Wahyuni; Raetzke, Klaus; Faupel, Franz [Faculty of Engineering, Kiel (Germany); Yang, Fan; Meyer, Andreas [Inst. of Materials Physics in Space, Koeln (Germany)

    2013-07-01

    Previous work on glass forming Pd-Cu-Ni-P alloys, showed that while a vast decoupling occurs between the diffusivity of Pd and of the smaller components, the diffusivities of all components merge close to the critical temperature T{sub c} of mode coupling theory. For Pd, the Stokes-Einstein relation holds in the whole range investigated encompassing more than 14 orders of magnitude. In order to check for the general validity of these results, we extended our investigations to the Zr-Cu-Ni-Ti-Be system. In this work, Co-57 and Zr-95 tracer diffusivities were determined in glass-forming Zr{sub 46.75}Ti{sub 8.25}Cu{sub 7.5}Ni{sub 10}Be{sub 27.5} above the melting temperature. In particular, measurements were carried out simultaneously to minimize artefacts from diffusion barriers and to reduce absolute errors. Even at 20 K above the liquidus temperature, the diffusivities of Zr and Co differ clearly by a factor of four, while Co tracer diffusivities agree very well with diffusivities determined by quasielastic neutron scattering. This together with measurements of the time dependence of the penetration profiles demonstrates the general reliability of the measurements. The results are discussed in connection with viscosity data and the Stokes-Einstein equation in terms of imperfect equilibration of the melt.

  7. Scientific Creativity and High Ability: Gender and academic level differences

    Directory of Open Access Journals (Sweden)

    Fernando Javier ESPARZA MOLINA

    2015-10-01

    Full Text Available  The purpose of this study was to investigate the influence of gender and educational level on scientific creativity among gifted/talented students. A cohort of creatividad científica y alta habilidad: diferencias de género y nivel educativo 78 secondary school students from 12 to 16 years old participated in this research. The scientific creativity was measured using the Creative Scientific Ability Test (Sak & Ayas, 2011 designed for secondary school students from 11 to 14 years old. Its theoretical framework sets up the measurement of a three dimensional structure: general creative abilities (fluency, flexibility and creativity, scientific creative abilities (hypothesis generation, hypothesis testing and evidence evaluation and scientific knowledge. This test has the right adequate psychometric properties with a Cronbach’s alpha coefficient of 0.848 (Sak & Ayas, 2013. Results indicated that male students scored significantly higher in a task named Interaction Graph which measures hypothesis generation in interdisciplinary science. The analysis also showed that students involved in upper education levels scores significantly higher in general fluency and in the task called The Food Chain which measures evidence evaluation in the area of ecology.

  8. Spatial Abilities of High-School Students in the Perception of Geologic Structures.

    Science.gov (United States)

    Kali, Yael; Orion, Nir

    1996-01-01

    Characterizes specific spatial abilities required in geology studies through the examination of the performance of high school students in solving structural geology problems on the geologic spatial ability test (GeoSAT). Concludes that visual penetration ability and the ability to perceive the spatial configuration of the structure are…

  9. Sociocultural Concept of High Ability and Heart-Mind Epistemology in Confucian Societies

    Science.gov (United States)

    Park, Jae

    2016-01-01

    This theoretical paper begins with a reflection on the dominant conceptions of "high ability", based on psychometrics, and examines claims that the ethos of a particular cultural heritage is essential to what "high ability" signifies. The article semantically distinguishes "giftedness" from "ability", using…

  10. Memory as a Factor in the Computational Efficiency of Dyslexic Children with High Abstract Reasoning Ability.

    Science.gov (United States)

    Steeves, K. Joyce

    1983-01-01

    A study involving dyslexic children (10-14 years old) with average and high reasoning ability and nondyslexic children with and without superior mathematical ability suggested that the high reasoning dyslexic Ss had similar abstract reasoning ability but lower computation and memory skills than mathematically gifted nondyslexic Ss. (CL)

  11. Using Self-Concept Instruments with High-Ability College Students: Reliability and Validity Evidence

    Science.gov (United States)

    Rinn, Anne N.; Cunningham, Lindy G.

    2008-01-01

    This study investigated the reliability and validity of the academic subscales of Marsh's Self-Description Questionnaire III and Neeman and Harter's Self-Perception Profile for College Students for use with high-ability college students. Participants included 100 high-ability college students and 196 average-ability college students enrolled in a…

  12. Using 20-million-year-old amber to test the super-Arrhenius behaviour of glass-forming systems.

    Science.gov (United States)

    Zhao, Jing; Simon, Sindee L; McKenna, Gregory B

    2013-01-01

    Fossil amber offers the opportunity to investigate the dynamics of glass-forming materials far below the nominal glass transition temperature. This is important in the context of classical theory, as well as some new theories that challenge the idea of an 'ideal' glass transition. Here we report results from calorimetric and stress relaxation experiments using a 20-million-year-old Dominican amber. By performing the stress relaxation experiments in a step-wise fashion, we measured the relaxation time at each temperature and, above the fictive temperature of this 20-million-year-old glass, this is an upper bound to the equilibrium relaxation time. The results deviate dramatically from the expectation of classical theory and are consistent with some modern ideas, in which the diverging timescale signature of complex fluids disappears below the glass transition temperature.

  13. Low-energy excitations in a low-viscous glass-forming liquid

    Indian Academy of Sciences (India)

    ... contribution to the overall low frequency Raman pattern is present even in this low-viscous liquid. The degree of disorder in this liquid is not so high and certain micro-ordering effects may take place due to hydrogen bonding. The results are discussed in the framework of the current phenomenological status of the field.

  14. Recent advances on glass-forming systems driven far from equilibrium. Special issue marking the completion of the Research Unit FOR 1394 `Nonlinear response to probe vitrification'

    Science.gov (United States)

    Fuchs, Matthias

    2017-08-01

    The nature of the glass transition is one of the frontier questions in Statistical Physics and Materials Science. Highly cooperative structural processes develop in glass-forming melts exhibiting relaxational dynamics which is spread out over many decades in time. While considerable progress has been made in recent decades towards understanding dynamical slowing-down in quiescent systems, the interplay of glassy dynamics with external fields reveals a wealth of novel phenomena yet to be explored. This special issue focuses on recent results obtained by the Research Unit FOR 1394 `Nonlinear response to probe vitrification' which was funded by the German Science Foundation (DFG). In the projects of the research unit, strong external fields were used in order to gain insights into the complex structural and transport phenomena at the glass transition under far-from-equilibrium conditions. This aimed inter alia to test theories of the glass transition developed for quiescent systems by pushing them beyond their original regime. Combining experimental, simulational, and theoretical efforts, the eight projects within the FOR 1394 measured and determined aspects of the nonlinear response of supercooled metallic, polymeric, and silica melts, of colloidal dispersions, and of ionic liquids. Applied fields included electric and mechanic fields, and forced active probing (`micro-rheology'), where a single probe is forced through the glass-forming host. Nonlinear stress-strain and force-velocity relations as well as nonlinear dielectric susceptibilities and conductivities were observed. While the physical manipulation of melts and glasses is interesting in its own right, especially technologically, the investigations performed by the FOR 1394 suggest to use the response to strong homogeneous and inhomogeneous fields as technique to explore on the microscopic level the cooperative mechanisms in dense melts of strongly interacting constituents. Questions considered concern the

  15. An energy landscape model for glass-forming liquids in three dimensions

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Hecksher, Tina; Dyre, Jeppe

    2006-01-01

    We present a three-dimensional lattice-gas model with trivial thermodynamics, but non-trivial dynamics. The model is characterized by each particle having its own random energy landscape. The equilibrium dynamics of the model were investigated by continuous time Monte Carlo simulations at two...... different densities at several temperatures. At high densities and low temperatures the model captures the important characteristics of viscous liquid dynamics. We thus observe non-exponential relaxation in the self part of the density auto-correlation function, and fragility plots of the self......-diffusion constant and relaxation times show non-Arrhenius behavior....

  16. Unique local structures of Ca, Ti, Fe and Zr in natural glasses formed by meteorite impact

    Science.gov (United States)

    Yoshiasa, Akira; Tobase, Tsubasa; Okube, Maki; Wang, Ling; Isobe, Hiroshi; Mashimo, Tsutomu; Graduate School of Science; Technology Collaboration; Materials; Structures Laboratory, Tokyo Institute of Technology Collaboration

    2015-06-01

    The local structures of cation in tektite from six strewn fields, impact-related glass, and non-impact-related glass were studied by Ca, Ti, Fe and Zr K-edge X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). Shock compression also causes local structural changes of gest and minor elements as well as transition of host structures. How to be left a record is peculiar by each element. The XAFS measurements were performed at the beam lines BL-NW10A and BL-9C, KEK, Japan. The comparison of XANES spectra and bonding distances between crystalline reference minerals and natural glasses was done. Based on the different valence states of iron, the degrees of oxidation states were estimated. The local structures of Ca, Ti and Zr ions are useful probe for physical conditions and formation process of glasses. Tektites experienced high quenching rates and a reduced atmospheric environment when they were ejected into outer space. Other impact-related glass, which was remained close to the crater, experienced a more complicated environment. The local structural changes of cation in the impact-related glass are rich in a variety. Analysis of local structure is help to compare their formation process and distinguish them.

  17. Transition from Arrhenius to non-Arrhenius temperature dependence of structural relaxation time in glass-forming liquids: continuous versus discontinuous scenario.

    Science.gov (United States)

    Popova, V A; Surovtsev, N V

    2014-09-01

    The temperature dependences of α relaxation time τ(α)(T) of three glass-forming liquids (salol, o-terphenyl, and α-picoline) were investigated by a depolarized light scattering technique. A detailed description of τ(α)(T) near T(A), the temperature of the transition from the Arrhenius law at high temperatures to a non-Arrhenius behavior of τ(α)(T) at lower temperatures, was done. It was found that this transition is quite sharp. If the transition is described as switching from the Arrhenius law to the Vogel-Fulcher-Tammann law, it occurs within the temperature range of about 15 K or less. Most of the known expressions for τ(α)(T) cannot describe this sharp transition. Our analysis revealed that this transition can be described either as a discontinuous transition in the spirit of the frustration-limited domain theory [D. Kivelson, G. Tarjus, X. Zhao, and S. A. Kivelson, Phys. Rev. E 53, 751 (1996)], implying a phase transition, or by a phenomenological expression recently suggested [B. Schmidtke, N. Petzold, R. Kahlau, M. Hofmann, and E. A. Rössler, Phys. Rev. E 86, 041507 (2012)], where the activation energy includes the term depending exponentially on temperature.

  18. Desiccation kinetics and biothermodynamics of glass forming trehalose solutions in thin films.

    Science.gov (United States)

    He, Xiaoming; Fowler, Alex; Menze, Michael; Hand, Steve; Toner, Mehmet

    2008-08-01

    In this study, the desiccation kinetics of aqueous trehalose solutions were investigated numerically by solving the coupled heat and mass transfer problem with a moving interface using the finite element method. The free volume models for vapor pressure and mutual diffusion coefficient were incorporated into the model to account for the effect of glass transition on the heat and mass transport process that ultimately determines the desiccation kinetics. It was found that the temperature in the film could drop significantly upon the initiation of drying due to the absorption of latent heat associated with water evaporation although the spatial distribution of temperature in the solution is very homogeneous. On the contrary, the spatial distribution of water content in the solution is non-homogeneous, particularly at the solution-vapor interface where an extremely thin layer of skin with extremely low molecular mobility usually forms during drying. The solution film can be dried to approximately 6-10 wt.% residual water within minutes for thin films; but drying times depends strongly on the initial film thickness, initial solution concentration, temperature, and convective coefficient. Desiccation to below 6 wt.% residual water is very slow due to the retarded water mobility in the extremely thin skin where the solution is in the glassy state. Since the water mobility in a trehalose solution or glass with 6-10% residual water is still high enough to allow degradative reactions to occur in a relatively short time at room temperature, it is important that the samples should be kept at a temperature around 0 degrees C or lower for storage after drying. Furthermore, approaches that might enable further quick reduction of the residual water to less than 6-10 wt.% are also proposed so that a sample could be preserved at super-zero or even room temperature. The established models and the reported results will be useful for the development of effective protocols for

  19. The Impact of a Language Learning Task on Instructional Outcomes in Two Student Populations: High-Ability and Average-Ability Students.

    Science.gov (United States)

    Nikolova, Ofelia; Taylor, Gregory

    2003-01-01

    High-ability (n=97) and average-ability students (n=84) were asked to read a Spanish passage on a computer and use glosses provided for certain words to aid in comprehension or create glosses using a Spanish-English dictionary and annotation software (experimental task). High-ability students performed significantly better after the experimental…

  20. Ergodicity and slowing down in glass-forming systems with soft potentials: No finite-temperature singularities

    Science.gov (United States)

    Eckmann, Jean-Pierre; Procaccia, Itamar

    2008-07-01

    The aim of this paper is to discuss some basic notions regarding generic glass-forming systems composed of particles interacting via soft potentials. Excluding explicitly hard-core interaction, we discuss the so-called glass transition in which a supercooled amorphous state is formed, accompanied by a spectacular slowing down of relaxation to equilibrium, when the temperature is changed over a relatively small interval. Using the classical example of a 50-50 binary liquid of N particles with different interaction length scales, we show the following. (i) The system remains ergodic at all temperatures. (ii) The number of topologically distinct configurations can be computed, is temperature independent, and is exponential in N . (iii) Any two configurations in phase space can be connected using elementary moves whose number is polynomially bounded in N , showing that the graph of configurations has the small world property. (iv) The entropy of the system can be estimated at any temperature (or energy), and there is no Kauzmann crisis at any positive temperature. (v) The mechanism for the super-Arrhenius temperature dependence of the relaxation time is explained, connecting it to an entropic squeeze at the glass transition. (vi) There is no Vogel-Fulcher crisis at any finite temperature T>0 .

  1. Characterization of the dynamics of glass-forming liquids from the properties of the potential energy landscape.

    Science.gov (United States)

    Banerjee, Sumilan; Dasgupta, Chandan

    2012-02-01

    We develop a framework for understanding the difference between strong and fragile behavior in the dynamics of glass-forming liquids from the properties of the potential energy landscape. Our approach is based on a master equation description of the activated jump dynamics among the local minima of the potential energy (the so-called inherent structures) that characterize the potential energy landscape of the system. We study the dynamics of a small atomic cluster using this description as well as molecular dynamics simulations and demonstrate the usefulness of our approach for this system. Many of the remarkable features of the complex dynamics of glassy systems emerge from the activated dynamics in the potential energy landscape of the atomic cluster. The dynamics of the system exhibits typical characteristics of a strong supercooled liquid when the system is allowed to explore the full configuration space. This behavior arises because the dynamics is dominated by a few lowest-lying minima of the potential energy and the potential energy barriers between these minima. When the system is constrained to explore only a limited region of the potential energy landscape that excludes the basins of attraction of a few lowest-lying minima, the dynamics is found to exhibit the characteristics of a fragile liquid. © 2012 American Physical Society

  2. Locus of Control, Academic Self-Concept, and Academic Dishonesty among High Ability College Students

    Science.gov (United States)

    Rinn, Anne N.; Boazman, Janette

    2014-01-01

    The purposes of the current study were to evaluate a measure of academic dishonesty and examine high ability college students' loci of control and its effect on behaviors of academic dishonesty, as moderated by academic self-concept. A total of 357 high ability college students enrolled at two universities in the southwestern United States took…

  3. Selecting the Right Educational Setting for High-Ability TCKS: A Mother's Perspective

    Science.gov (United States)

    Yamada, Sylvia

    2015-01-01

    Meeting the needs of gifted students is challenging even in traditional contexts and settings. Well-known issues include a limited choice of schools, underrepresentation of certain populations, and, often, the lack of facilities and support for high-ability students. Imagine, then, the further complexities of high-ability Third Culture Kids (TCKs)…

  4. Changing the Tendency of Glass-Forming Liquid To Crystallize by Moving Along Different Isolines in the T-p Phase Diagram

    DEFF Research Database (Denmark)

    Adrjanowicz, Karolina; Koperwas, Kajetan; Tarnacka, Magdalena

    2016-01-01

    Controlling crystallization and glass-forming tendencies of molecular liquids is of great scientific and practical importance. In the present work, we show that a lot can be learned regarding this process by introducing temperature and pressure as thermodynamic control variables. For the glass...

  5. SAT predicts GPA better for high ability subjects: Implications for Spearman's Law of Diminishing Returns.

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-04-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman's Law of Diminishing Returns, that a test's predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g.

  6. Spatial ability and spatial memory in high school students with different levels of mathematical fluency.

    OpenAIRE

    Tikhomirova, T.N.; Malykh, S.B.; Bogomaz, S.A.; Sudneva, O.V.; Kovas, Yulia

    2013-01-01

    The study investigated spatial ability and visuo-spatial memory in groups of high school students with different levels of mathematical fluency. We used the Mental Rotation Task and Corsi Block-Tapping Task to measure spatial ability and visuo-spatial memory, respectively. A statistically significant difference was found between the groups with different levels of math fluency in terms of effectiveness of spatial ability and level of visuo-spatial memory. Statistically significant sex differe...

  7. Improving Chinese Junior High School Students' Ability to Ask Critical Questions

    Science.gov (United States)

    Huang, Xiao; Lederman, Norman G.; Cai, Chaojing

    2017-01-01

    The present study explores ways to enhance students' question-asking ability (i.e., the ability to ask critical questions), which is the premise of scientific inquiry and a precondition for effective science teaching. A survey of junior high school students in Zhejiang province in China showed that students' questioning behavior was not well…

  8. The Pitch-Matching Ability of High School Choral Students: A Justification for Continued Direct Instruction

    Science.gov (United States)

    Riegle, Aaron M.; Gerrity, Kevin W.

    2011-01-01

    The purpose of this study was to determine the pitch-matching ability of high school choral students. Years of piano experience, middle school performance experience, and model were considered as variables that might affect pitch-matching ability. Gender of participants was also considered when identifying the effectiveness of each model.…

  9. Cognitive, adaptive, and psychosocial differences between high ability youth with and without autism spectrum disorder.

    Science.gov (United States)

    Doobay, Alissa F; Foley-Nicpon, Megan; Ali, Saba R; Assouline, Susan G

    2014-08-01

    Research on Autism Spectrum Disorder (ASD) is thriving; however, scant empirical research has investigated how ASD manifests in high ability youth. Further research is necessary to accurately differentiate high ability students with ASD from those without the disorder, and thus decrease the risk of misdiagnosis. The purpose of the present study is to provide an empirical account of the intellectual, adaptive, and psychosocial functioning of high ability youth with and without ASD utilizing a group study design. Forty youth with high cognitive ability and ASD and a control group of 41 youth with high cognitive ability and no psychological diagnosis were included in the study. In comparison to the control group, the ASD group showed poorer functioning on measures of processing speed, adaptive skills, and broad psychological functioning, as perceived by parents and teachers. These findings have significant implications for diagnosing ASD among those with high ability, and the development of related psychological and educational interventions to address talent domains and areas of concern.

  10. Logical Reasoning Abilities of Junior High School Students in the Province of Cotabato, Philippines

    Directory of Open Access Journals (Sweden)

    Paul John B. Ongcoy

    2016-11-01

    Full Text Available Reasoning abilities of the learners and its development was well-discussed in the world of education. The higher the ability of the person to reason abstractly, the higher the probability that a person will effectively function in the society. Thus, it is the main goal of the K-12 Curriculum of the Department of Education to improve the reasoning abilities and formal reasoning among students in the country. The higher the reasoning ability of a person, the more productive he is. The ability of logical reasoning has an essential function in the academic performance of students and their construction of the concepts. This study aimed to determine the logical reasoning abilities of 150 randomly selected junior high school students. Specifically, this study aimed to determine the logical reasoning abilities namely combinatorial reasoning, controlling variables, correlation reasoning, probabilistic reasoning and proportional reasoning among the grade 10 junior high school students and determine whether there is a significant difference in students’ logical reasoning abilities according to their gender. The respondents answered the Test of Logical Thinking (TOLT. Thirty respondents were interviewed to verify their answers. The findings of the study led to the following conclusions: most students correctly answered problems in probabilistic reasoning and least number of students correctly answered problems in proportional reasoning and combinatorial reasoning and, male and female respondents have equal performances in problems pertaining to combinatorial reasoning, controlling variables, correlational reasoning and probabilistic reasoning but female respondents are better in proportional reasoning than the male respondents.

  11. Team Accelerated Instruction, Initials And Problem-Solves Ability In Junior High School

    Directory of Open Access Journals (Sweden)

    Sri Adi Widodo

    2017-08-01

    Full Text Available This research aims to test the effectiveness of Team Accelerated Instruction against the ability of the students solve math problems in terms of the ability of the students. This study is an experiment with 367 students as research samples taken using the technique of cluster. The variable memecahan is the ability of the research problem, the ability of the beginning and the learning model. Data analysis is analysis of variance. It can be concluded that (1 TAI more effective use than in DI, (2 early-capable students are better if compared with students early-capable of low and high, (3 early-capable students are learning, Team Acceerated Instruction more effectively used if compared to DI, and (4 on TAI and DI, the ability of the same relative solve math problems

  12. The Relationship Between Utilization of Computer Games and Spatial Abilities Among High School Students

    Directory of Open Access Journals (Sweden)

    Vahid Motamedi

    2015-07-01

    Full Text Available This study aimed at investigating the relationship between computer game use and spatial abilities among high school students. The sample consisted of 300 high school male students selected through multi-stage cluster sampling. Data gathering tools consisted of a researcher made questionnaire (to collect information on computer game usage and the Newton and Bristol spatial ability questionnaire with reliability value of .85. Data were analyzed using Pearson’s correlation coefficient. Results showed that there was a meaningful relationship between the use of computer games and spatial ability (r = .59 and p = 00.00, there was a meaningful relationship between the use of computer games and the spatial perceived ability (r = .60 and p = .00, there was a meaningful relationship between the use of computer games and mental rotation ability (r = .48 and p = .00 and there was a meaningful relationship between computer game use and spatial visualization ability (r = .48 and p = .00. In general, the findings showed there was a positive and a significant relationship between the use of computer games and spatial abilities in students.

  13. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    OpenAIRE

    Jeong, Jae; Lee, Sung; Jeon, Je-Beom; Kim, Suk

    2015-01-01

    Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the va...

  14. The Munich High Ability Test Battery (MHBT): A multidimensional, multimethod approach

    OpenAIRE

    CHRISTOPH PERLETH; KURT A. HELLER

    2008-01-01

    After a brief introduction the theoretical basis of the Munich High Ability Test-Battery (MHBT) will be outlined in the first part of the article. The MHBT has been developed in the framework of the Munich longitudinal study of giftedness and talent. The MHBT includes not only cognitive predictors measuring several dimensions and types of giftedness concerning intellectual, creative or social abilities etc., but also giftedness-relevant non-cognitive personality and social moderators measurin...

  15. The Relationship between Utilization of Computer Games and Spatial Abilities among High School Students

    Science.gov (United States)

    Motamedi, Vahid; Yaghoubi, Razeyah Mohagheghyan

    2015-01-01

    This study aimed at investigating the relationship between computer game use and spatial abilities among high school students. The sample consisted of 300 high school male students selected through multi-stage cluster sampling. Data gathering tools consisted of a researcher made questionnaire (to collect information on computer game usage) and the…

  16. Improving Junior High School Students' Mathematical Analogical Ability Using Discovery Learning Method

    Science.gov (United States)

    Maarif, Samsul

    2016-01-01

    The aim of this study was to identify the influence of discovery learning method towards the mathematical analogical ability of junior high school's students. This is a research using factorial design 2x2 with ANOVA-Two ways. The population of this research included the entire students of SMPN 13 Jakarta (State Junior High School 13 of Jakarta)…

  17. The Influence of Personality, Parenting Styles, and Perfectionism on Performance Goal Orientation in High Ability Students

    Science.gov (United States)

    Miller, Angie L.; Speirs Neumeister, Kristie L.

    2017-01-01

    The current study explores relationships among gender, perceived parenting style, the personality traits of conscientiousness and neuroticism, perfectionism, and achievement goal orientation in a high ability and high achieving young adult population. Using data from Honors College students at a Midwestern university, a path model suggests that…

  18. [Evidence against the myth of adjustment problems of people with high intellectual abilities].

    Science.gov (United States)

    Borges del Rosal, Africa; Hernández-Jorge, Carmen; Rodríguez-Naveiras, Elena

    2011-08-01

    Personal and social adjustment of high-ability children and adolescents is a very important issue in the specialized literature. The differences found between data for and against appropriate adjustment in gifted children and adolescents could be explained by conceptual or methodological biases. In this work, the relation between adjustment and high abilities are contrasted in a sample of teenagers from the Canary Islands, using a screening procedure based on their scores in intelligence tests. Results show that, although gifted adolescents differ significantly from their peers in the control group in socio-economic variables and academic performance, there are no differences in personal, social and educational adjustment. We conclude that adjustment problems and high ability are independent variables, and there is no evidence to support that gifted individuals have adjustment problems.

  19. Looking at the high ability/giftedness through the lens of curriculum studies

    Directory of Open Access Journals (Sweden)

    Soraia Napoleão Freitas

    2011-12-01

    Full Text Available From diving in the educational field, either in teaching or research in Special Education, this article postulates bring visibility to a curricular discussion strongly marked by the educational practice of learners with high ability/giftedness and having the "lighthouse flag” the inclusion policy school principles, not just theorizing about the elements of the theme. Curriculum is understood as a territory of knowledge and power, so the manufacturing process of the curriculum in the wake of the inclusive hillside – a journey which aims to solidify egalitarian social link - can put up as an potentiating agent of different actions for the education of students with high ability/giftedness, protecting them from moments of discrimination, segregation and personal, family, school and social exclusion. Therefore, this article takes up an invitation to educators to look at the prerogatives of education that hosts students with high ability/giftedness with the lens of curriculum studies.

  20. High functioning individuals with schizophrenia have preserved social perception but not mentalizing abilities.

    Science.gov (United States)

    Karpouzian, Tatiana M; Alden, Eva C; Reilly, James L; Smith, Matthew J

    2016-03-01

    Social perception and mentalizing are fundamental social cognitive abilities that are related to functioning and are impaired in schizophrenia. A novel approach to examine the relationship between social cognition and community functioning is to first functionally categorize individuals with schizophrenia and then evaluate social cognitive performance. We evaluated differences in social perception and mentalizing among controls (CON, n=45), high functioning individuals with schizophrenia (HF-SCZ, n=36), and individuals with low functioning schizophrenia (LF-SCZ, n=24). Analyses revealed that HF-SCZ had preserved social perceptual abilities compared to LF-SCZ. Both schizophrenia groups had impaired mentalizing abilities compared to CON, but did not differ from each other. These results suggest that HF-SCZ and LF-SCZ are characterized by differences in the perceptual aspects of social cognition and encourage future research to evaluate the neural basis underlying this preserved ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Effect of specific soccer training on general soccer ability of high fit tribal soccer players

    OpenAIRE

    Dr.Gopal Chandra Saha; Dr. Hiralal Adhikari

    2014-01-01

    The purpose of the study was to investigate the effect of specific soccer training on General Soccer ability (volleying Skill) by using Mcdonald Soccer Test of high fit tribal soccer players. ninety, high fit tribal Soccer players out of two hundred and seventy, 9th and 10th grade school level tribal Soccer players from Ergoda School parihati of paschim Medinipur, District of West Bengal were randomly selected as the tribal subjects for this study. To ascertain the high fit tribal Soccer play...

  2. High-demand jobs: age-related diversity in work ability?

    Science.gov (United States)

    Sluiter, Judith K

    2006-07-01

    High-demand jobs include 'specific' job demands that are not preventable with state of the art ergonomics knowledge and may overburden the bodily capacities, safety or health of workers. An interesting question is whether the age of the worker is an important factor in explanations of diversity in work ability in the context of high-demand jobs. In this paper, the work ability of ageing workers is addressed according to aspects of diversity in specific job demands and the research methods that are needed to shed light upon the relevant associated questions. From the international literature, a body of evidence was elicited concerning rates of chronological ageing in distinct bodily systems and functions. Intra-age-cohort differences in capacities and work ability, however, require (not yet existing) valid estimates of functional age or biological age indices for the specific populations of workers in high-demand jobs. Many studies have drawn on the highly demanding work of fire-fighters, ambulance workers, police officers, medical specialists, pilots/astronauts and submarine officers. Specific job demands in these jobs can be physical, mental or psychosocial in origin but may cause combined task-level loadings. Therefore, the assessment of single demands probably will not reveal enough relevant information about work ability in high-demand jobs and there will be a call for more integrated measures. Existing studies have used a variety of methodologies to address parts of the issue: task analyses for quantifying physical work demands, observations of psychological and physiological parameters, measures of psychosocial work demands and health complaints. Specific details about the work ability of ageing workers in high-demand jobs are scarce. In general, specific demands are more likely to overtax the capacities of older workers than those of younger workers in high-demand jobs, implying greater repercussions for health, although these effects also vary considerably

  3. A comprehensive test of evolutionarily increased competitive ability in a highly invasive plant species

    Science.gov (United States)

    Joshi, Srijana; Gruntman, Michal; Bilton, Mark; Seifan, Merav; Tielbörger, Katja

    2014-01-01

    Background and Aims A common hypothesis to explain plants' invasive success is that release from natural enemies in the introduced range selects for reduced allocation to resistance traits and a subsequent increase in resources available for growth and competitive ability (evolution of increased competitive ability, EICA). However, studies that have investigated this hypothesis have been incomplete as they either did not test for all aspects of competitive ability or did not select appropriate competitors. Methods Here, the prediction of increased competitive ability was examined with the invasive plant Lythrum salicaria (purple loosestrife) in a set of common-garden experiments that addressed these aspects by carefully distinguishing between competitive effect and response of invasive and native plants, and by using both intraspecific and interspecific competition settings with a highly vigorous neighbour, Urtica dioica (stinging nettle), which occurs in both ranges. Key Results While the intraspecific competition results showed no differences in competitive effect or response between native and invasive plants, the interspecific competition experiment revealed greater competitive response and effect of invasive plants in both biomass and seed production. Conclusions The use of both intra- and interspecific competition experiments in this study revealed opposing results. While the first experiment refutes the EICA hypothesis, the second shows strong support for it, suggesting evolutionarily increased competitive ability in invasive populations of L. salicaria. It is suggested that the use of naturally co-occurring heterospecifics, rather than conspecifics, may provide a better evaluation of the possible evolutionary shift towards greater competitive ability. PMID:25301818

  4. A Comparison of High School Student Interests across Three Grade and Ability Levels.

    Science.gov (United States)

    Gill, Newell T.

    1980-01-01

    Students (Grades 9-11) in two Florida metropolitan high schools rated their interest in 28 topics, such as travel, popular music, religion, the opposite sex, war, and politics. Interests were analyzed by sex, grade, and ability track in English (Honors, Average, Basic). Findings, especially those on romantic interests, are discussed. (SJL)

  5. Long term high flow heated oxygen treatment in COPD – lung function and physical ability

    DEFF Research Database (Denmark)

    Weinreich, Ulla; Storgaard, Line; Hockey, Hans

    2017-01-01

    Introduction: Long term oxygen therapy (LTOT) improves survival in patients with COPD with resting hypoxemia. Despite this, a progressive loss of lung function and physical ability is expected in COPD. The AIRVO device delivers nasal high flow (NHF) warmed and humidified oxygen-enriched air, 20...

  6. The Relationship between Critical Thinking Abilities and Classroom Management Skills of High School Teachers

    Science.gov (United States)

    Demirdag, Seyithan

    2015-01-01

    High school teachers experience difficulties while providing effective teaching approaches in their classrooms. Some of the difficulties are associated with the lack of classroom management skills and critical thinking abilities. This quantitative study includes non-random selection of the participants and aims to examine critical thinking…

  7. Against the Odds: Academic Resilience among High-Ability African American Adolescents Living in Rural Poverty

    Science.gov (United States)

    Ellis, Wendy Taylor

    2010-01-01

    This qualitative study investigated the internal and external protective factors that serve to ameliorate barriers to academic achievement posed by the cultural factors of poverty, minority status, and rural residence for high-ability students, rendering them academically resilient. While there has been ample research on underachievement among…

  8. Development of an Instrument to Evaluate High School Students' Chemical Symbol Representation Abilities

    Science.gov (United States)

    Wang, Zuhao; Chi, Shaohui; Luo, Ma; Yang, Yuqin; Huang, Min

    2017-01-01

    Chemical symbol representation is a medium for transformations between the actual phenomena of the macroscopic world and those of the sub-microscopic world. The aim of this study is to develop an instrument to evaluate high school students' chemical symbol representation abilities (CSRA). Based on the current literature, we defined CSRA and…

  9. The Relationship between Ethical Sensitivity, High Ability and Gender in Higher Education Students

    Science.gov (United States)

    Schutte, Ingrid; Wolfensberger, Marca; Tirri, Kirsi

    2014-01-01

    This study examined the ethical sensitivity of high-ability undergraduate students (n=731) in the Netherlands who completed the 28-item Ethical Sensitivity Scale Questionnaire (ESSQ) developed by Tirri & Nokelainen (2007; 2011). The ESSQ is based on Narvaez' (2001) operationalization of ethical sensitivity in seven dimensions. The following…

  10. Associations between Conceptual Reasoning, Problem Solving, and Adaptive Ability in High-Functioning Autism

    Science.gov (United States)

    Williams, Diane L.; Mazefsky, Carla A.; Walker, Jon D.; Minshew, Nancy J.; Goldstein, Gerald

    2014-01-01

    Abstract thinking is generally highly correlated with problem-solving ability which is predictive of better adaptive functioning. Measures of conceptual reasoning, an ecologically-valid laboratory measure of problem-solving, and a report measure of adaptive functioning in the natural environment, were administered to children and adults with and…

  11. The Role of High-School Duration for University Students' Motivation, Abilities and Achievements

    Science.gov (United States)

    Meyer, Tobias; Thomsen, Stephan L.

    2018-01-01

    We study the effects of learning intensity and duration of high school on students' motivation, abilities and achievements at university. The empirical analysis is based on primary panel data from an education reform in the German state of Saxony-Anhalt that reduced university preparatory schooling from 13 to 12 years but left the curriculum…

  12. The Impact of Active Visualisation of High School Students on the Ability to Memorise Verbal Definitions

    Science.gov (United States)

    Šmajdek, Anamarija; Selan, Jurij

    2016-01-01

    The era of visual communication influences the cognitive strategies of the individual. Education, too, must adjust to these changes, which raises questions regarding the use of visualisation in teaching. In the present study, we examine the impact of visualisation on the ability of high school students to memorise text. In the theoretical part of…

  13. The Effect of Journal Writing on Mathematics Achievement among High-Ability Students in Singapore

    Science.gov (United States)

    Tan, Tracy; Garces-Bacsal, Rhoda Myra

    2013-01-01

    This study examined the effect of journal writing on mathematics achievement in high-ability students in Singapore. It assessed both the cognitive benefits of journal writing (as evidenced through gains in math test scores) and the socio-affective benefits of journal writing (as demonstrated in their personal reflections) as the students learned…

  14. Perfectionism in High-Ability Students: Relational Precursors and Influences on Achievement Motivation

    Science.gov (United States)

    Speirs Neumeister, Kristie L.; Finch, Holmes

    2006-01-01

    The purpose of the present study was to create and test a model that (a) illustrated variables influencing the development of perfectionism, and (b) demonstrated how different types of perfectionism may influence the achievement goals of high-ability students. Using a multiple groups path analysis, the researchers found that parenting style was…

  15. Detection of high ability children by teachers and parents: Psychometric quality of new rating checklists for the assessment of intellectual, creative and social ability

    Directory of Open Access Journals (Sweden)

    ULRIKE SOMMER

    2008-06-01

    Full Text Available In the present study we devised scales for teachers’ and parents’ estimation of intellectual, creative and social abilities of fourth grade elementary school pupils. Their scores were related to psychometrically determined ability scores. Ninety-three school pupils in the age range between 9.3 and 11.2 years, as well as their parents and teachers took part. The new rating checklists proved as sufficiently reliable (particularly the teachers’ version. Analyses of validity showed a high correspondence in parents’ and teachers’ estimations of cognitive intelligence, but much lower correspondence for creativity and social ability. Correlating teachers’ and parents’ estimates with the respective psychometric tests shows that teachers and parents were better at identifying intellectual (highability than detecting creative and social abilities. With the exception of social (highability, where girls were usually regarded as highly socially gifted by their parents, there were no differences in parents’ and teachers’ estimations of boys and girls.

  16. The intelligence of observation: improving high school students' spatial ability by means of intervention unit

    Science.gov (United States)

    Patkin, Dorit; Dayan, Ester

    2013-03-01

    This case study of one class versus a control group focused on the impact of an intervention unit, which is not part of the regular curriculum, on the improvement of spatial ability of high school students (forty-six 12th-graders, aged 17-18, both boys and girls) in general as well as from a gender perspective. The study explored three sub-abilities: mental rotation (MR), spatial visualization (VS) and spatial orientation (SO). Findings indicated that the spatial orientation of the experimental group students had considerably improved. The findings also illustrated a significant gender-based advantage in favour of the boys in some of the spatial abilities even before the implementation of the intervention unit. The hypothesis relating to the reduction of the gender differences was not corroborated.

  17. Visualisation Ability of Senior High School Students with Using GeoGebra and Transparent Mica

    Science.gov (United States)

    Thohirudin, M.; Maryati, TK; Dwirahayu, G.

    2017-04-01

    Visualisation ability is an ability to process, inform, and transform object which suitable for geometry topic in math. This research aims to describe the influence of using software GeoGebra and transparent mica for student’s visualisation ability. GeoGebra is shortness of geometry and algebra. GeoGebra is an open source program that is created for math. Transparent mica is a tool that is created by the author to transform a geometry object. This research is a quantitative experiment model. The subject of this research were students in grade XII of science program in Annajah Senior High School Rumpin with two classes which one as an experiment class (science one) and another one as a control class (science two). Experiment class use GeoGebra and transparent mica in the study, and control class use powerpoint in the study. Data of student’s visualisation ability is collected from posttest with visual questions which are gifted at the end of the research to both classes with topic “transformation geometry”. This research resulted that studying with GeoGebra and transparent mica had a better influence than studying with powerpoint to student’s visualisation ability. The time of study in class and the habit of the students to use software and tool affected the result of research. Although, GeoGebra and transparent mica can give help to students in transformation geometry topic.

  18. A comprehensive test of evolutionarily increased competitive ability in a highly invasive plant species.

    Science.gov (United States)

    Joshi, Srijana; Gruntman, Michal; Bilton, Mark; Seifan, Merav; Tielbörger, Katja

    2014-12-01

    A common hypothesis to explain plants' invasive success is that release from natural enemies in the introduced range selects for reduced allocation to resistance traits and a subsequent increase in resources available for growth and competitive ability (evolution of increased competitive ability, EICA). However, studies that have investigated this hypothesis have been incomplete as they either did not test for all aspects of competitive ability or did not select appropriate competitors. Here, the prediction of increased competitive ability was examined with the invasive plant Lythrum salicaria (purple loosestrife) in a set of common-garden experiments that addressed these aspects by carefully distinguishing between competitive effect and response of invasive and native plants, and by using both intraspecific and interspecific competition settings with a highly vigorous neighbour, Urtica dioica (stinging nettle), which occurs in both ranges. While the intraspecific competition results showed no differences in competitive effect or response between native and invasive plants, the interspecific competition experiment revealed greater competitive response and effect of invasive plants in both biomass and seed production. The use of both intra- and interspecific competition experiments in this study revealed opposing results. While the first experiment refutes the EICA hypothesis, the second shows strong support for it, suggesting evolutionarily increased competitive ability in invasive populations of L. salicaria. It is suggested that the use of naturally co-occurring heterospecifics, rather than conspecifics, may provide a better evaluation of the possible evolutionary shift towards greater competitive ability. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Analysis of Factors Influencing Interest in STEM Career: Comparison between American and Turkish High School Students with High Ability

    Science.gov (United States)

    Bahar, Abdulkadir; Adiguzel, Tufan

    2016-01-01

    The low number of students studying or applying for STEM subjects and workforce demand has been prioritized in almost all countries policies. This study intended to examine factors that influenced American and Turkish students to pursue a degree or career in STEM-related fields. Participants of the study were 86 high-ability students selected from…

  20. The theory of multiple intelligences in the identification of high-ability students

    Directory of Open Access Journals (Sweden)

    Daniel Hernández-Torrano

    2014-01-01

    Full Text Available This study provides a framework to implement the theory of multiple intelligences (MI in the identification of high-ability students in secondary education. The internal structure of three scales to assess students' MI (students, parents and teachers' ratings was analyzed in a sample of 566 students nominated as gifted by their teachers. Participants aged 11 to 16 years (M = 14.85, SD = 1.08. The results indicated differentiated intellectual profiles depending on the informant estimating students' MI. This study provided evidence for two components that allow us to analyze the cognitive competence of high-ability students beyond the areas commonly assessed at school: an academic component composed by the linguistic, logical-mathematical, naturalistic, and visual-spatial intelligences; and a non-academic component statistically loaded by the bodily-kinesthetic, musical and social intelligences. Convergence of the two components in the three scales was evidenced; and correlations between these components and students' objective performance on a psychometric intelligence test were found to be low. Finally, the utility of the MI scales to identify high-ability students in secondary education is discussed.

  1. Developing Science Process Skills and Problem Solving Abilities Based on Outdoor Learning in Junior High School

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    S. Wahyuni

    2017-04-01

    Full Text Available This research aims to develop science process skills and problem-solving abilities based on outdoor learning in junior high school. This study uses a mixed method design embedded experimental models. Data was performed in the qualitative and quantitative analysis. Qualitative data analysis is used to determine the science process skills while quantitative data analysis is used to determine the increasing problem-solving ability by using normalized gain (N gain formula. The results show that the science process skills developed at every phase comprise of making observations, formulating hypotheses, experiment, create data, classify and analyze the data, formulating its conclusions, communicate, and apply the concepts and make predictions obtained by the average value of 75.33 in the good category. While the problem-solving ability of students based on outdoor learning also increased by 0.58 in the medium category. The conclusions of this research show that the application of outdoor learning can be teacher use as an alternative to learning, so it is quite effective in developing science process skills and problem-solving abilities.

  2. Effect of Self-etch Adhesives on Self-sealing Ability of High-Copper Amalgams

    OpenAIRE

    Saied Mostafa Moazzami; Horieh Moosavi; Maryam Moddaber; Reza Parvizi; Mohamad Hadi Moayed; Nima Mokhber; Michael Meharry; Reza B Kazemi

    2016-01-01

    Statement of the Problem: Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. Purpose: The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap ...

  3. High temperature enhances the ability of Trichoderma asperellum to infect Pleurotus ostreatus mycelia.

    Science.gov (United States)

    Qiu, Zhiheng; Wu, Xiangli; Zhang, Jinxia; Huang, Chenyang

    2017-01-01

    Trichoderma asperellum is one of the species which can be isolated from contaminated Pleurotus ostreatus cultivation substrate with green mold disease. This study focused on the relationship between high temperature and infectivity of T. asperellum to P. ostreatus. Antagonism experiments between T. asperellum and P. ostreatus mycelia revealed that high temperature-treated P. ostreatus mycelia were more easily infected by T. asperellum and covered by conidia. Microscopic observation also showed that P. ostreatus mycelia treated with high temperature could adsorb more T. asperellum conidia. Furthermore, conidia obtained from T. asperellum mycelia grown at 36°C featured higher germination rate compared with that incubated at 28°C. High temperature-treated T. asperellum mycelia can produce conidia in shorter periods, and T. asperellum mycelia were less sensitive to high temperature than P. ostreatus. Deactivated P. ostreatus mycelia can induce T. asperellum cell wall-degrading enzymes (CWDEs) and P. ostreatus mycelia subjected to high temperature showed induced CWDEs more effective than those incubated at 28°C. Moreover, T. asperellum showed higher CWDEs activity at high temperature. In dual cultures, hydrogen peroxide (H2O2) increased after 36°C, and high concentration of H2O2 could significantly inhibit the growth of P. ostreatus mycelia. In summary, our findings indicated for the first time that high temperature can induce a series of mechanisms to enhance infection abilities of T. asperellum to P. ostreatus mycelia and to cause Pleurotus green mold disease.

  4. High temperature enhances the ability of Trichoderma asperellum to infect Pleurotus ostreatus mycelia

    Science.gov (United States)

    Qiu, Zhiheng; Wu, Xiangli; Zhang, Jinxia

    2017-01-01

    Trichoderma asperellum is one of the species which can be isolated from contaminated Pleurotus ostreatus cultivation substrate with green mold disease. This study focused on the relationship between high temperature and infectivity of T. asperellum to P. ostreatus. Antagonism experiments between T. asperellum and P. ostreatus mycelia revealed that high temperature-treated P. ostreatus mycelia were more easily infected by T. asperellum and covered by conidia. Microscopic observation also showed that P. ostreatus mycelia treated with high temperature could adsorb more T. asperellum conidia. Furthermore, conidia obtained from T. asperellum mycelia grown at 36°C featured higher germination rate compared with that incubated at 28°C. High temperature-treated T. asperellum mycelia can produce conidia in shorter periods, and T. asperellum mycelia were less sensitive to high temperature than P. ostreatus. Deactivated P. ostreatus mycelia can induce T. asperellum cell wall-degrading enzymes (CWDEs) and P. ostreatus mycelia subjected to high temperature showed induced CWDEs more effective than those incubated at 28°C. Moreover, T. asperellum showed higher CWDEs activity at high temperature. In dual cultures, hydrogen peroxide (H2O2) increased after 36°C, and high concentration of H2O2 could significantly inhibit the growth of P. ostreatus mycelia. In summary, our findings indicated for the first time that high temperature can induce a series of mechanisms to enhance infection abilities of T. asperellum to P. ostreatus mycelia and to cause Pleurotus green mold disease. PMID:29073211

  5. High temperature enhances the ability of Trichoderma asperellum to infect Pleurotus ostreatus mycelia.

    Directory of Open Access Journals (Sweden)

    Zhiheng Qiu

    Full Text Available Trichoderma asperellum is one of the species which can be isolated from contaminated Pleurotus ostreatus cultivation substrate with green mold disease. This study focused on the relationship between high temperature and infectivity of T. asperellum to P. ostreatus. Antagonism experiments between T. asperellum and P. ostreatus mycelia revealed that high temperature-treated P. ostreatus mycelia were more easily infected by T. asperellum and covered by conidia. Microscopic observation also showed that P. ostreatus mycelia treated with high temperature could adsorb more T. asperellum conidia. Furthermore, conidia obtained from T. asperellum mycelia grown at 36°C featured higher germination rate compared with that incubated at 28°C. High temperature-treated T. asperellum mycelia can produce conidia in shorter periods, and T. asperellum mycelia were less sensitive to high temperature than P. ostreatus. Deactivated P. ostreatus mycelia can induce T. asperellum cell wall-degrading enzymes (CWDEs and P. ostreatus mycelia subjected to high temperature showed induced CWDEs more effective than those incubated at 28°C. Moreover, T. asperellum showed higher CWDEs activity at high temperature. In dual cultures, hydrogen peroxide (H2O2 increased after 36°C, and high concentration of H2O2 could significantly inhibit the growth of P. ostreatus mycelia. In summary, our findings indicated for the first time that high temperature can induce a series of mechanisms to enhance infection abilities of T. asperellum to P. ostreatus mycelia and to cause Pleurotus green mold disease.

  6. The identification and inclusion of students with characteristics of high abilities/giftedness: relevant discussions

    Directory of Open Access Journals (Sweden)

    Tatiane Negrini

    2008-12-01

    Full Text Available Thinking about education in general and about the advances that have been coming up, brings us to reflect on the proposal of the inclusive school. The Brazilian educational policies point in this direction and new propositions appear to the school in order to understand how to make significant changes in the daily education. Accordingly, this article is to hold a discussion regarding the identification of students with high abilities/giftedness, articulating with some ideas proposed by the inclusive education. It is with that highlight the importance of identifying these students for a more genuine inclusion of these students in the educational context. In this sense, is used as input theoretical Gardner (1995, Renzulli (2004, Perez (2004, Virgolim (2007, Vieira (2005, among other authors who assist in the discussion of this issue. The considerations made about the high abilities and their process of identification highlight the importance of a great attention facing the process of identification and relevance of this to the actual inclusion of students with high skills in the educational context. Since they are not identified, these students may not be receiving the necessary guidance to learn and develop their potential, often distancing themselves from colleagues and friends. Thus, it is a debate about the appropriate identification of these students and how it can contribute to the inclusion of them.

  7. Networked Pd (core) @ polyaniline (shell) composite: Highly electro-catalytic ability and unique selectivity

    Science.gov (United States)

    Xia, Youyi; Liu, Ning; Sun, Ling; Xu, Hao; Gao, Hong; Lu, Taofeng

    2018-01-01

    A networked composite (Pd@PANI), which is self-assemblied freely from Pd (core) @polyaniline (shell) nanoparticles, has been prepared successfully by a facilely one-step approach. Owing to the conductive environment and acid-doped behavior provided by PANI, the composite exhibits highly catalytic ability in the reaction involving acidic reactants. For instance, in the HCOOH electro-oxidation, 9.16 times of specific activity (comparing with that when using commercial Pd/C catalyst) is observed. Meanwhile, the as-prepared product is unable to catalyze some other systems like the electro-oxidation of C2H5OH, showing novel and unique selectivity. Those would open up new routes for synthesizing high-performance Pd-based catalysts, and could also shed some light on synthesizing new types of selective catalysts.

  8. Polarized millijoule fiber laser system with high beam quality and pulse shaping ability

    Science.gov (United States)

    Zhang, Rui; Tian, Xiaocheng; Xu, Dangpeng; Zhou, Dandan; Zong, Zhaoyu; Li, Hongxun; Fan, Mengqiu; Huang, Zhihua; Zhu, Na; Su, Jingqin; Zhu, Qihua; Jing, Feng

    2017-05-01

    The coherent amplification network (CAN) aims at developing a laser system based on the coherent combination of multiple laser beams, which are produced through a network of high beam quality optical fiber amplifiers. The scalability of the CAN laser facilitates the development of many novel applications, such as fiber-based acceleration, orbital debris removal and inertial confinement fusion energy. According to the requirements of CAN and the front end of high-power laser facilities, a millijoule polarized fiber laser system was studied in this paper. Using polarization maintaining Ytterbium-fiber laser system as the seed, and 10-μm core Yb-doped fiber amplifier as the first power amplifier and 40-μm core polarizing (PZ) photonic crystal fiber (PCF) as the second power amplifier, the all-fiber laser system outputs 1.06-mJ energy at 10 ns and diffraction limited mode quality. Using 85-μm rod-type PCF as the third power amplifiers, 2.5-mJ energy at 10-ns pulse width was obtained with better than 500:1 peak-to-foot pulse shaping ability and fundamental mode beam quality. The energy fluctuation of the system is 1.3% rms with 1-mJ output in one hour. When using phase-modulated pulse as the seed, the frequency modulation to amplitude modulation (FM-to-AM) conversion ratio of the system is better than 5%. This fiber laser system has the advantages of high beam quality, high beam shaping ability, good stability, small volume and free of maintenance, which can be used in many applications.

  9. High-Achieving High School Students and Not so High-Achieving College Students: A Look at Lack of Self-Control, Academic Ability, and Performance in College

    Science.gov (United States)

    Honken, Nora B.; Ralston, Patricia A. S.

    2013-01-01

    This study investigated the relationship among lack of self-control, academic ability, and academic performance for a cohort of freshman engineering students who were, with a few exceptions, extremely high achievers in high school. Structural equation modeling analysis led to the conclusion that lack of self-control in high school, as measured by…

  10. The Impact of Active Visualisation of High School Students on the Ability to Memorise Verbal Definitions

    Directory of Open Access Journals (Sweden)

    Anamarija Šmajdek

    2016-12-01

    Full Text Available The era of visual communication influences the cognitive strategies of the individual. Education, too, must adjust to these changes, which raises questions regarding the use of visualisation in teaching. In the present study, we examine the impact of visualisation on the ability of high school students to memorise text. In the theoretical part of the research, we first clarify the concept of visualisation. We define the concept of active visualisation and visualisation as a means of acquiring and conveying knowledge, and we describe the different kinds of visualisation (appearance-based analogies and form-based analogies, specifically defining appearance-based schemata visualisations (where imagery is articulated in a typical culturally trained manner. In the empirical part of the research, we perform an experiment in which we evaluate the effects of visualisation on students’ ability to memorise a difficult written definition. According to the theoretical findings, we establish two hypotheses. In the first, we assume that the majority of the visualisations that students form will be appearance-based schemata visualisations. This hypothesis is based on the assumption that, in visualisation, people spontaneously use analogies based on imagery and schemas that are typical of their society. In the second hypothesis, we assume that active visualisation will contribute to the students’ ability to memorise text in a statistically significant way. This hypothesis is based on the assumption that the combination of verbal and visual experiences enhances cognitive learning. Both hypotheses were confirmed in the research. As our study only dealt with the impact of the most spontaneous type of appearance based schemata visualisations, we see further possibilities in researching the influence of visualisations that are more complex formally.

  11. Effect of Self-etch Adhesives on Self-sealing Ability of High-Copper Amalgams.

    Science.gov (United States)

    Moazzami, Saied Mostafa; Moosavi, Horieh; Moddaber, Maryam; Parvizi, Reza; Moayed, Mohamad Hadi; Mokhber, Nima; Meharry, Michael; B Kazemi, Reza

    2016-12-01

    Similar to conventional amalgam, high-copper amalgam alloy may also undergo corrosion, but it takes longer time for the resulting products to reduce microleakage by sealing the micro-gap at the tooth/amalgam interface. The aim of this study was to evaluate the effect of self-etch adhesives with different pH levels on the interfacial corrosion behavior of high-copper amalgam restoration and its induction potential for self-sealing ability of the micro-gap in the early hours after setting by means of Electro-Chemical Tests (ECTs). Thirty cylindrical cavities of 4.5mm x 4.7mm were prepared on intact bicuspids. The samples were divided into five main groups of application of Adhesive Resin (AR)/ liner/ None (No), on the cavity floor. The first main group was left without an AR/ liner (No). In the other main groups, the types of AR/ liner used were I-Bond (IB), Clearfil S3 (S3), Single Bond (SB) and Varnish (V). Each main group (n=6) was divided into two subgroups (n=3) according to the types of the amalgams used, either admixed ANA 2000 (ANA) or spherical Tytin (Tyt). The ECTs, Open Circuit Potential (OCP), and the Linear Polarization Resistance (LPR) for each sample were performed and measured 48 hours after the completion of the samples. The Tyt-No and Tyt-IB samples showed the highest and lowest OCP values respectively. In LPR tests, the Rp values of ANA-V and Tyt-V were the highest (lowest corrosion rate) and contrarily, the ANA-IB and Tyt-IB samples, with the lowest pH levels, represented the lowest Rp values (highest corrosion rates). Some self-etch adhesives may increase interfacial corrosion potential and self-sealing ability of high-copper amalgams.

  12. How Different Molecular Architectures Influence the Dynamics of H-Bonded Structures in Glass-Forming Monohydroxy Alcohols.

    Science.gov (United States)

    Wikarek, M; Pawlus, S; Tripathy, Satya N; Szulc, A; Paluch, M

    2016-06-30

    Primary alcohols have been an active area of research since the beginning of the 20th century. The main problem in studying monohydroxy alcohols is the molecular origin of the slower Debye relaxation, whereas the faster process, recognized as structural relaxation, remains much less investigated. This is because in many primary alcohols the structural process is strongly overlapped by the dominating Debye relaxation. Additionally, there is still no answer for many fundamental questions concerning the origin of the molecular characteristic properties of these materials. One of them is the role of molecular architecture in the formation of hydrogen-bonded structures and its potential connection to the relaxation dynamics of Debye and structural relaxation processes. In this article, we present the results of ambient and high-pressure dielectric studies of monohydroxy alcohols with similar chemical structures but different carbon chain lengths (2-ethyl-1-butanol and 2-ethyl-1-hexanol) and positions of the OH- group (2-methyl-2-hexanol and 2-methyl-3-hexanol). New data are compared with previously collected results for 5-methyl-2-hexanol. We note that differences in molecular architecture have a significant influence on the formation of hydrogen-bonded structures, which is reflected in the behavior of the Debye and structural relaxation processes. Intriguingly, studying the relaxation dynamics in monohydroxy alcohols at high pressures of up to p = 1700 MPa delivers a fundamental bridge to understand the potential connection between molecular conformation and its response to the characteristic properties of these materials.

  13. The Munich High Ability Test Battery (MHBT: A multidimensional, multimethod approach

    Directory of Open Access Journals (Sweden)

    CHRISTOPH PERLETH

    2008-06-01

    Full Text Available After a brief introduction the theoretical basis of the Munich High Ability Test-Battery (MHBT will be outlined in the first part of the article. The MHBT has been developed in the framework of the Munich longitudinal study of giftedness and talent. The MHBT includes not only cognitive predictors measuring several dimensions and types of giftedness concerning intellectual, creative or social abilities etc., but also giftedness-relevant non-cognitive personality and social moderators measuring interests, motivations, learning emotions, self-concepts or family and school climate, educational style, quality of instruction, etc. The MHBT-instruments (different scales and dimensions are described in greater detail.In the second part of the article, after dealing with the objectivity, the reliability, and the validity of the MHBT, the authors discuss the standardization procedure including the development of grade-based T-norms respectively as well as several talent-profiles, e.g. of gifted achievers vs. underachievers, intellectual, creative, social talents or linguistic, math, science talent profiles etc. Finally, examples of talent search for gifted programs and case studies on the basis of MHBT should illustrate multidimensional identification procedures.The MHBT fulfills the most relevant assessment tasks belonging to the gifted educational and counseling practice. The usefulness of the MHBT in the framework of giftedness research as well as of gifted program evaluation studies has also been proven in the last decade. Hence the MHBT offers many opportunities to assessing giftedness and talent.

  14. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments.

    Science.gov (United States)

    Jurak, Edita; Patyshakuliyeva, Aleksandrina; de Vries, Ronald P; Gruppen, Harry; Kabel, Mirjam A

    2015-01-01

    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments.

  15. Imitated prosodic fluency predicts reading comprehension ability in good and poor high school readers

    Directory of Open Access Journals (Sweden)

    Mara Breen

    2016-07-01

    Full Text Available Researchers have established a relationship between beginning readers’ silent comprehension ability and their prosodic fluency, such that readers who read aloud with appropriate prosody tend to have higher scores on silent reading comprehension assessments. The current study was designed to investigate this relationship in two groups of high school readers: Specifically Poor Comprehenders (SPCs, who have adequate word level and phonological skills but poor reading comprehension ability, and a group of age- and decoding skill-matched controls. We compared the prosodic fluency of the two groups by determining how effectively they produced prosodic cues to syntactic and semantic structure in imitations of a model speaker’s production of syntactically and semantically varied sentences. Analyses of pitch and duration patterns revealed that speakers in both groups produced the expected prosodic patterns; however, controls provided stronger durational cues to syntactic structure. These results demonstrate that the relationship between prosodic fluency and reading comprehension continues past the stage of early reading instruction. Moreover, they suggest that prosodically fluent speakers may also generate more fluent implicit prosodic representations during silent reading, leading to more effective comprehension.

  16. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments

    Science.gov (United States)

    de Vries, Ronald P.; Gruppen, Harry; Kabel, Mirjam A.

    2015-01-01

    The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments. PMID:26237450

  17. Compost Grown Agaricus bisporus Lacks the Ability to Degrade and Consume Highly Substituted Xylan Fragments.

    Directory of Open Access Journals (Sweden)

    Edita Jurak

    Full Text Available The fungus Agaricus bisporus is commercially grown for the production of edible mushrooms. This cultivation occurs on compost, but not all of this substrate is consumed by the fungus. To determine why certain fractions remain unused, carbohydrate degrading enzymes, water-extracted from mushroom-grown compost at different stages of mycelium growth and fruiting body formation, were analyzed for their ability to degrade a range of polysaccharides. Mainly endo-xylanase, endo-glucanase, β-xylosidase and β-glucanase activities were determined in the compost extracts obtained during mushroom growth. Interestingly, arabinofuranosidase activity able to remove arabinosyl residues from doubly substituted xylose residues and α-glucuronidase activity were not detected in the compost enzyme extracts. This correlates with the observed accumulation of arabinosyl and glucuronic acid substituents on the xylan backbone in the compost towards the end of the cultivation. Hence, it was concluded that compost grown A. bisporus lacks the ability to degrade and consume highly substituted xylan fragments.

  18. The Impact of Problem-Based Learning Approach to Senior High School Students’ Mathematics Critical Thinking Ability

    Directory of Open Access Journals (Sweden)

    Reviandari Widyatiningtyas

    2015-07-01

    Full Text Available The study was report the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students’ prior mathematical ability to student’s mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from excellent and moderate school level. The research instruments a set of mathematical critical thinking ability test, and the data were analyzed by using two ways ANOVA and t-test. The research found that the problem based learning approach has significant impact to the ability of students’ mathematics critical thinking in terms of school level and students’ prior mathematical abilities. Furthermore. This research also found that there is no interaction between learning approach and school level, and learning approach and students’ prior mathematics ability to students’ mathematics critical thinking ability.

  19. SAT predicts GPA better for high ability subjects: Implications for Spearman’s Law of Diminishing Returns

    Science.gov (United States)

    Coyle, Thomas; Snyder, Anissa; Pillow, David; Kochunov, Peter

    2011-01-01

    This research examined the predictive validity of the SAT (formerly, the Scholastic Aptitude Test) for high and low ability groups. SAT scores and college GPAs were obtained from the 1997 National Longitudinal Survey of Youth. Subjects were classified as high or low ability by g factor scores from the Armed Services Vocational Aptitude Battery. SAT correlations with GPA were higher for high than low ability subjects. SAT g loadings (i.e., SAT correlations with g) were equivalent for both groups. This is the first study to show that the predictive validity of the SAT varies for ability groups that differ in g. The results contradict a presumption, based on Spearman’s Law of Diminishing Returns, that a test’s predictive validity should be lower for high ability subjects. Further research is needed to identify factors that contribute to the predictive validity of the SAT for groups that differ in g. PMID:21562615

  20. FeSiBP bulk metallic glasses with high magnetization and excellent magnetic softness

    Science.gov (United States)

    Makino, Akihiro; Kubota, Takeshi; Chang, Chuntao; Makabe, Masahiro; Inoue, Akihisa

    Fe-based amorphous alloy ribbons are one of the major soft magnetic materials, because of their superior magnetic properties such as the relatively high saturation magnetization ( Js) of 1.5-1.6 T and good magnetic softness. However, the preparation of the ordinary amorphous magnetic alloys requires cooling rates higher than 10 4 K/s due to the low glass-forming ability (GFA) and thus restricts the material outer shape. Recently, Fe-metalloid-based bulk metallic glasses (BMGs) containing glass-forming elements such as Al, Ga, Nb, Mo, Y and so forth have been developed. These alloys have high GFA, leading to the formation of BMG rod with diameters of mm-order. However, the glass-forming metal elements in BMGs result in a remarkable decrease in magnetization. Basically, Js depends on Fe content; hence, high Js requires high Fe content in the Fe-based amorphous alloys or BMGs. On the other hand, high GFA requires a large amount of glass-forming elements in the alloys, which results in lower Fe content. Therefore, in substances, the coexistence of high Js and high GFA is difficult. Since this matter should be immensely important from academia to industry in the material field, a great deal of effort has been devoted; however, it has remained unsolved for many years. In this paper, we present a novel Fe-rich FeSiBP BMG with high Js of 1.51 T comparable to the ordinary Fe-Si-B amorphous alloy now in practical use as well as with high GFA leading to a rod-shaped specimen of 2.5 mm in diameter, obtained by Cu-mold casting in air.

  1. The Enhancement of Mathematical Reasoning Ability of Junior High School Students by Applying Mind Mapping Strategy

    Science.gov (United States)

    Ayal, Carolina S.; Kusuma, Yaya S.; Sabandar, Jozua; Dahlan, Jarnawi Afgan

    2016-01-01

    Mathematical reasoning ability, are component that must be governable by the student. Mathematical reasoning plays an important role, both in solving problems and in conveying ideas when learning mathematics. In fact there ability are not still developed well, even in middle school. The importance of mathematical reasoning ability (KPM are…

  2. Academic Reading ability of first-year students: what's high school ...

    African Journals Online (AJOL)

    Both groups were administered a pre-test and post-test of academic reading ability. The dependent variable was academic reading ability and the independent variables were matric grade and prior exposure. Two measures of reading ability were used, namely a reading comprehension and a cloze passage. An analysis of ...

  3. EFFECT OF LEARNING WITH ABDUCTIVE-DEDUCTIVE STRATEGY TOWARDS THE ACHIEVEMENT OF REASONING ABILITY OF HIGH SCHOOL STUDENTS

    Directory of Open Access Journals (Sweden)

    Ali Shodikin

    2017-09-01

    Full Text Available The purpose of this study was to investigate the effect of learning with abductive-deductive strategy towards the achievement of mathematical reasoning abilities of high school students. Research carried out an experimental pretest-posttest design and the control group was not randomized in class XI student at one high school in Pati, Central Java, Indonesia. Data analysis was conducted quantitative research based on early mathematical ability categories (KAM and overall. The results showed that the achievement of mathematical reasoning abilities that students acquire learning abductive-deductive strategy better than students who received the expository learning. In more detail of KAM categories, only middle category that show achievement of mathematical reasoning abilities better. While in upper and under categories have the same reasoning abilities achievements. This research is expected teachers can encourage students to do abduction and deduction in the learning achievement of students’ mathematical reasoning abilities.

  4. Critical Thinking Skills of an Eighth Grade Male Student with High Mathematical Ability in Solving Problem

    Science.gov (United States)

    Ismail

    2018-01-01

    This study aims to describe student’s critical thinking skill of grade VIII in solving mathematical problem. A qualitative research was conducted to a male student with high mathematical ability. Student’s critical thinking skill was obtained from a depth task-based interview. The result show that male student’s critical thinking skill of the student as follows. In understanding the problem, the student did categorization, significance decoding, and meaning clarification. In devising a plan he examined his ideas, detected his argument, analyzed his argument and evaluated his argument. During the implementation phase, the skill that appeared were analyzing of the argument and inference skill such as drawing conclusion, deliver alternative thinking, and problem solving skills. At last, in rechecking all the measures, they did self-correcting and self-examination.

  5. The dynamics of the high-speed abilities of young players 12, 13, 14 years old

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    Vladimir Perevoznyk

    2014-08-01

    Full Text Available Purpose: to determine the dynamics of the high-speed abilities of young players. Materials and Methods: the change in performance of speed players at women's 30 meters run, using both specific and non-specific methods. In the training process of players 12–14 years to use specific tools, as well as holding athletic activities for the development of speed. The literature analyzed for the development of young players quickness, educational testing, methods of mathematical statistics. Results: the dynamics of development of physical skill of speed for young players using specific and non-specific methods. Conclusions: the use of the training process in microcycle preparatory period of athletics orientation training gives a positive result in the development of the physical speed quality.

  6. Basic design concepts for perpendicular magnetic recording—from viewpoints of high writing ability and resolution

    Science.gov (United States)

    Nakamura, Yoshihisa

    2005-02-01

    At the beginning of the research into perpendicular magnetic recording about 30 years ago, through many experiments, the authors found out several basic principles for realizing its potential. These are still useful for the design of a head and medium system for perpendicular magnetic recording. To realize the so-called "Tera-bit storage", the recording layer of a medium which consists of small diameter and high Ku fine magnetic grains must be written by a single-pole head possessing a higher writing ability and a sharper field gradient than the current heads. In this paper, "how to generate a strong and sharp perpendicular field from a single-pole writing head" is described. In particular, two key points are presented; the first is energizing methods for the main pole of a single-pole head and the second is a method for effectively utilizing of the head-medium magneto-static interaction.

  7. High-expanding cortical regions in human development and evolution are related to higher intellectual abilities.

    Science.gov (United States)

    Fjell, Anders M; Westlye, Lars T; Amlien, Inge; Tamnes, Christian K; Grydeland, Håkon; Engvig, Andreas; Espeseth, Thomas; Reinvang, Ivar; Lundervold, Astri J; Lundervold, Arvid; Walhovd, Kristine B

    2015-01-01

    Cortical surface area has tremendously expanded during human evolution, and similar patterns of cortical expansion have been observed during childhood development. An intriguing hypothesis is that the high-expanding cortical regions also show the strongest correlations with intellectual function in humans. However, we do not know how the regional distribution of correlations between intellectual function and cortical area maps onto expansion in development and evolution. Here, in a sample of 1048 participants, we show that regions in which cortical area correlates with visuospatial reasoning abilities are generally high expanding in both development and evolution. Several regions in the frontal cortex, especially the anterior cingulate, showed high expansion in both development and evolution. The area of these regions was related to intellectual functions in humans. Low-expanding areas were not related to cognitive scores. These findings suggest that cortical regions involved in higher intellectual functions have expanded the most during development and evolution. The radial unit hypothesis provides a common framework for interpretation of the findings in the context of evolution and prenatal development, while additional cellular mechanisms, such as synaptogenesis, gliogenesis, dendritic arborization, and intracortical myelination, likely impact area expansion in later childhood. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. The Impact of Problem-Based Learning Approach to Senior High School Students' Mathematics Critical Thinking Ability

    Science.gov (United States)

    Widyatiningtyas, Reviandari; Kusumah, Yaya S.; Sumarmo, Utari; Sabandar, Jozua

    2015-01-01

    The study reported the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students' prior mathematical ability to student's mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from…

  9. Analysis of Motor Abilities Development in Male and Female High Schoolers

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    Є. В. Срібний

    2016-08-01

    Full Text Available The pupose of the research is to define the peculiarities of motor abilities development in male and female high schoolers. Materials and methods. To solve the tasks set, the research relies on the following methods used: analysis of scientific literature, pedagogical testing and methods of mathematical statistics of data reduction. The participants in the study were 10 boys and 14 girls of the 10th grade, 14 boys and 10 girls of the 11th grade. Conclusions. The level of motor abilities development in the 10th-11th-grade girls and the 11th-grade boys is at the sufficient level, while this level in the 10th-grade boys is average. The statistically significant difference between the 10th-grade boys and girls is observed in the following tests: assessment of time parameters of movement (error in 10 seconds, assessment of perception of strength parameters of movement (standing long jump at ½ of MAX, bending and unbending of arms in suspension, bent suspension. The boys performed better in these tests than girls. The statistically significant difference between the 11th-grade boys and girls shows in the following tests: jumping with “increases of weight”, assessment of time parameters of movement (error in 5, 10 seconds, assessment of perception of strength parameters of movement, shuttle run, bending and unbending of arms in suspension, bent suspension. The girls performed better in jumping with “increases of weight”, assessment of time parameters of movement, assessment of perception of strength parameters of movement. The correlation analysis of the indicators of motor abilities development proves that the “shuttle run” test has more connections with the other tests in case of the 10th-grade girls (3 сonnections at r > 0.6; for the 10th-grade boys such tests are “bending and unbending of arms from the lying position”, “bending and unbending of arms in suspension” (5 сonnections at r > 0.6; for the 11th‑grade girls

  10. Impact of motor abilities on belly dance performance in female high school students.

    Science.gov (United States)

    Srhoj, Ljerka; Mihaljević, Dodi; Jukić, Josefina

    2008-09-01

    The aim of the study was to determine the relation of motor abilities and belly dance performance in female high school students, 1st to 4th graders aged 15-18 years. A battery of 19 motor tests were used and nine belly dance elements evaluated in the study sample that included 148 students aged 15-16 (1st and 2nd graders) and 123 students aged 17-18 (3rd and 4th graders). Factor analysis of the motor space isolated six factors in either study group: in 1st and 2nd graders, the first factor integrated coordination, trunk strength, aerobic and muscle endurance, and speed of lower extremity movements; second factor defined explosive strength; third factor defined flexibility; fourth factor defined rhythm coordination; fifth factor defined equilibrium; and sixth factor defined back musculature strength; in 3rd and 4th graders, the first factor integrated coordination and lower extremity explosive strength; second factor defined flexibility; third factor integrated trunk strength and aerobic-muscular endurance; fourth factor defined equilibrium; fifth factor defined rhythm coordination; and sixth factor defined lower extremity strength. Factor analysis of the scores allocated to particular belly dance elements isolated only one factor as a factor of the general specific ability for belly dance performance. Regression analysis in the latent space indicated the factor of flexibility, which is responsible for muscle tone regulation, to be the best predictor of belly dance performance in 1st and 2nd graders. In 3rd and 4th graders, the factor of rhythm coordination was found to be superior in predicting belly dance performance, followed by the factor of trunk strength and aerobic-muscular endurance, the factor integrating coordination and lower extremity strength, and factor of equilibrium.

  11. Apoptosis inducing ability of silver decorated highly reduced graphene oxide nanocomposites in A549 lung cancer.

    Science.gov (United States)

    Khan, Merajuddin; Khan, Mujeeb; Al-Marri, Abdulhadi H; Al-Warthan, Abdulrahman; Alkhathlan, Hamad Z; Siddiqui, Mohammed Rafiq H; Nayak, Vadithe Lakshma; Kamal, Ahmed; Adil, Syed F

    2016-01-01

    Recently, graphene and graphene-based materials have been increasingly used for various biological applications due to their extraordinary physicochemical properties. Here, we demonstrate the anticancer properties and apoptosis-inducing ability of silver doped highly reduced graphene oxide nanocomposites synthesized by employing green approach. These nano composites (PGE-HRG-Ag) were synthesized by using Pulicaria glutinosa extract (PGE) as a reducing agent and were evaluated for their anticancer properties against various human cancer cell lines with tamoxifen as the reference drug. A correlation between the amount of Ag nanoparticles on the surface of highly reduced graphene oxide (HRG) and the anticancer activity of nanocomposite was observed, wherein an increase in the concentration of Ag nanoparticles on the surface of HRG led to the enhanced anticancer activity of the nanocomposite. The nanocomposite PGE-HRG-Ag-2 exhibited more potent cytotoxicity than standard drug in A549 cells, a human lung cancer cell line. A detailed investigation was undertaken and Fluorescence activated cell sorting (FACS) analysis demonstrated that the nanocomposite PGE-HRG-Ag-2 showed G0/G1 phase cell cycle arrest and induced apoptosis in A549 cells. Studies such as, measurement of mitochondrial membrane potential, generation of reactive oxygen species (ROS) and Annexin V-FITC staining assay suggested that this compound induced apoptosis in human lung cancer cells.

  12. [Reading ability of junior high school students in relation to self-evaluation and depression].

    Science.gov (United States)

    Yamashita, Toshiya; Hayashi, Takashi

    2012-01-01

    Guidelines for the diagnosis of reading disorders in elementary school students were published recently in Japan. On the basis of these guidelines, we administrated reading test batteries to 43 Japanese junior high-school students from grade two. The reading test consisted of single sounds, single words, and single sentences. We evaluated the reading speed and the number of reading errors made by the test takers; their performance was compared with the normal value for elementary school students in grade six, as stated in the guidelines. The reading ability of the junior high-school students was not higher than that of the elementary school students. Seven students (16.3%) were found to have reading difficulties (RD group) and they met the criterion for diagnosis of reading disorder as per the guidelines. Three students had difficulties in reading single sounds and single words, but they faced no problems when reading single sentences. It was supposed that the strategies used by the students for reading sentences may have differed from those used for reading single sounds or single words. No significant differences were found between the RD and non-RD group students on scores of scholastic self-evaluation, self-esteem, and depressive symptoms. Therefore, reading difficulty did not directly influence the level of self-evaluation or depression.

  13. (abstract) Undercooling Studies of the Bulk Metallic Glass Forming Zr(sub 41.2)Ti(sub 13.8)Cu(sub 12.5)Ni(sub 10.0)Be(sub 22.5) Alloy During Containerless Electrostatic Levitation Processing

    Science.gov (United States)

    Kim, Y. J.; Busch, R.; Johnson, W. L.; Rulison, A. J.; Rhim, W. K.

    1995-01-01

    Bulk glass forming metallic alloys have long been desired for technological applications and for investigation into liquid undercooling, solidification processes, and thermophysical properties. A glass forming alloy Zr(sub 41.2)Ti(sub 13.8)Cu(sub 12.5)Ni(sub 10.0)Be(sub 22.5) was used to investigate the thermal treatments affecting undercooling and vitrification. The experiments were performed using the high temperature high vacuum electrostatic levitator at JPL. A sample approximately 3 mm in diameter was melted, superheated, undercooled, and solidified while levitated in high vacuum. The results show that when the sample was held above its melting temperature for a sufficient period of time to dissolve oxides and then cooled faster than a critical cooling rate, it undercooled to the glass transition temperature, T(sub g), and formed a glassy alloy. The required critical cooling rate for metallic glass formation was obtained to be between 0.9 K per second and 1.2 K per second for the 42.4 mg sample.

  14. High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

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    Tian Qin

    Full Text Available BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE and sequence-based typing (SBT were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01. The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01. Legionella pneumophila was the most frequently isolated species (98.9%, and the isolated serogroups included serogroups 3 (25.3%, 6 (23.4%, 5 (19.2%, 1 (18.5%, 2 (10.2%, 8 (0.4%, 10 (0.8%, 9 (1.9% and 12 (0.4%. Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control

  15. Does career dissatisfaction affect the ability of family physicians to deliver high-quality patient care?

    Science.gov (United States)

    DeVoe, Jennifer; Fryer Jr, George E; Hargraves, J Lee; Phillips, Robert L; Green, Larry A

    2002-03-01

    A usual source of care is associated with better health outcomes. Dissatisfaction among family physicians and general practitioners (FP/GPs) may compromise the accessibility of a usual source of care and the quality of services. We examined the association between FP/GP dissatisfaction and an inability to deliver high-quality care. We performed a secondary data analysis of the Community Tracking Study (CTS) Physician Survey (1996-1997). The study included a nationally representative sample of more than 12,000 nonfederal physicians practicing direct patient care in the United States. We measured associations of career dissatisfaction with physicians&rsquo perceptions of their ability to provide high-quality care as defined by 6 survey items. Multivariate analyses controlled for the effects of personal, professional, and practice characteristics. Among FP/GPs in 1996-1997, more than 17% were dissatisfied. Age was the most significant personal factor associated with dissatisfaction; 25.1% of those aged 55 to 64 years reported dissatisfaction compared with only 10.1% of those younger than 35 years. Other personal or professional characteristics significantly associated with FP/GP dissatisfaction included osteopathic training, graduation from a foreign medical school, full practice ownership, and an income of less than $100,000. Physicians dissatisfied with their careers were much more likely to report difficulties in caring for patients, strongly disagreeing (vs strongly agreeing, odds ratio [OR] 1.0) that they had enough clinical freedom (OR 7.89; 95% confidence interval [CI], 4.86-12.83); continuous patient relationships (OR 7.11; 95% CI, 4.90-10.33); no financial penalties for clinical decisions (OR 4.44; 95% CI, 3.13-6.31); adequate time with patients (OR 4.42; 95% CI, 2.84-6.87); ability to provide quality care (OR 4.26; 95% CI, 2.88-6.31); and sufficient communication with specialists (OR 3.57; CI, 2.20-5.80). An inability to care for patients is significantly

  16. High Prevalence, Genetic Diversity and Intracellular Growth Ability of Legionella in Hot Spring Environments

    Science.gov (United States)

    Zhou, Haijian; Wang, Huanxin; Xu, Ying; Zhao, Mingqiang; Guan, Hong; Li, Machao; Shao, Zhujun

    2013-01-01

    Background Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. Methods Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. Results Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (pLegionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (pLegionella pneumophila was the most frequently isolated species (98.9%), and the isolated serogroups included serogroups 3 (25.3%), 6 (23.4%), 5 (19.2%), 1 (18.5%), 2 (10.2%), 8 (0.4%), 10 (0.8%), 9 (1.9%) and 12 (0.4%). Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. Conclusions Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control and prevention strategies are

  17. Corrosion behaviour of Al86.0Co7.6Ce6.4 glass forming alloy with different microstructures

    Science.gov (United States)

    Li, C. L.; Wang, P.; Sun, S. Q.; Voisey, K. T.; McCartney, D. G.

    2016-10-01

    It has been extensively reported that Al-TM-RE amorphous alloy has excellent mechanical properties and corrosion resistance. In this paper, the corrosion behaviour of an Al86.0Co7.6Ce6.4 glass forming alloy with different microstructures is investigated through electrochemical experiments and microscopy. Results show the effect of microstructure. Laser and electron beam surface melting processes produce rapidly solidified microstructures with different extents of passivation compared to the as-cast alloy. An amorphous surface layer produced by these surface treatments had superior corrosion resistance compared with the crystalline alloy. As-cast and laser treated Al86.0Co7.6Ce6.4 suffered localised corrosion in the Al/Al11Ce3 eutectic region whereas the amorphous material exhibited uniform corrosion. Compared with the electrochemical behaviour of AA2024 and Alclad 2024, the fully amorphous layer prepared by combined laser-electron beam treatment exhibited advantages such as the more negative corrosion potential, the higher pitting potential and the uniform corrosion mechanism, which indicates that this material is a potential anode candidate in the protection of AA2024.

  18. Individual Differences in Speech and Language Ability Profiles in Areas of High Deprivation

    Science.gov (United States)

    Jordan, Julie-Ann; Coulter, Lorraine

    2017-01-01

    Speech and language ability is not a unitary concept; rather, it is made up of multiple abilities such as grammar, articulation and vocabulary. Young children from socio-economically deprived areas are more likely to experience language difficulties than those living in more affluent areas. However, less is known about individual differences in…

  19. High seed dispersal ability of Pinus canariensis in stands of contrasting density inferred from genotypic data

    Directory of Open Access Journals (Sweden)

    Unai López de Heredia

    2015-04-01

    Full Text Available Aim of the study: Models that combine parentage analysis from molecular data with spatial information of seeds and seedlings provide a framework to describe and identify the factors involved in seed dispersal and recruitment of forest species. In the present study we used a spatially explicit method (the gene shadow model in order to assess primary and effective dispersal in Pinus canariensis. Area of study: Pinus canariensis is endemic to the Canary Islands (Spain. Sampling sites were a high density forest in southern slopes of Tenerife and a low density stand in South Gran Canaria. Materials and methods: We fitted models based on parentage analysis from seeds and seedlings collected in two sites with contrasting stand density, and then compared the resulting dispersal distributions. Main results: The results showed that: 1 P. canariensis has a remarkable dispersal ability compared to other pine species; 2 there is no discordance between primary and effective dispersals, suggesting limited secondary dispersal by animals and lack of Janzen-Connell effect; and 3 low stand densities enhance the extent of seed dispersal, which was higher in the low density stand. Research highlights: The efficient dispersal mechanism of P. canariensis by wind inferred by the gene shadow model is congruent with indirect measures of gene flow, and has utility in reconstructing past demographic events and in predicting future distribution ranges for the species.

  20. A New Look on the Development and Learning of Children with High Abilities

    Directory of Open Access Journals (Sweden)

    Giovana Mattei

    2007-09-01

    Full Text Available When we approach the subject development and learning soon in them it comes the mind the process of education and specific learning of the pertaining to school environment. However we must have clearly that the development as well as learning is complex processes that involves the pertaining not only the school environment but the development of the physical, mental and social of the human being. The human being is not only intellect, is a complex being with strong cognitive and ambient support, of interactions, learnings and consequently development and evolution. This capacity to learn during all the life, exactly without being present in a pertaining school environment, is what in them it becomes only beings capable to be able to interpret, to reveal knowledge, to develop itself socially intellectual and, that is learning in potential. With regard to the children superendowed or carrying of high innumerable abilities doubts and contradictions thus permeat the relative aspects to its development and learning, different visions and perspectives are analyzed in order to contribute and to clarify aspects related to these children special, so that school and educators can assist in significant way these children potentializing his capacities.

  1. Cognitive abilities and motivational processes in high school students' science achievement and engagement

    Science.gov (United States)

    Lau, Shun

    The dissertation presents two analytic approaches, a variable-centered and person-centered approach, to investigating holistic patterns of the cognitive, motivational, and affective correlates of science achievement and engagement in a sample of 491 10th and 11th grade high-school students. Building on Snow's (1989) idea of two pathways to achievement outcomes, Study 1 adopted a variable-centered approach to examining how cognitive and motivational factors associated with the performance and commitment pathways, respectively, contributed to the prediction of achievement outcomes in science. Results of hierarchical regression analyses showed that (a) students' cognitive abilities were the strongest predictors of their performance in science as measured by standardized test scores; (b) motivational processes enhanced the predictive validity for science test scores and grades beyond the variance accounted for by ability and demography; (c) motivational processes were the strongest predictors of students' commitment to science in the form of situational engagement and anticipated choices of science-related college majors and careers; and (d) competence beliefs served as a point of contact between the performance and commitment pathways. These results are consistent with Snow's (1989) conjecture that both performance and commitment pathway-related factors are necessary for understanding the full range of person-level inputs to achievement outcomes. Study 2 adopted a person-centered approach to examining holistic organizations of psychological factors within individuals and their relations to science achievement and engagement. Four types of students characterized by unique configurations of cognitive, motivational, and affective attributes were identified in both the male and female subsamples using inverse factor analysis. Type membership was found to distinguish students in various indicators of science achievement and engagement. Two of the four types were also found

  2. Synthesis, characterization and dye removal ability of high capacity polymeric adsorbent: Polyaminoimide homopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoodi, Niyaz Mohammad, E-mail: nm_mahmoodi@aut.ac.ir [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Najafi, Farhood [Department of Resin and Additives, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Khorramfar, Shooka [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Amini, Farrokhlegha [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Arami, Mokhtar [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Polyaminoimide homopolymer (PAIHP) was synthesized and characterized. Black-Right-Pointing-Pointer Kinetics data followed pseudo-second order kinetic model. Black-Right-Pointing-Pointer Isotherm data followed Langmuir isotherm. Black-Right-Pointing-Pointer Q{sub 0} for DR31, DR23, DB22 and AB25 was 6667, 5555, 9090 and 5882 mg/g, respectively. Black-Right-Pointing-Pointer PAIHP was regenerated at pH 12. - Abstract: In this paper, polyaminoimide homopolymer (PAIHP) was synthesized and its dye removal ability was investigated. Physical characteristics of PAIHP were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Direct Red 31 (DR31), Direct Red 23 (DR23), Direct Black 22 (DB22) and Acid Blue 25 (AB25) were used as model compounds. The kinetic and isotherm of dye adsorption were studied. The effect of operational parameter such as adsorbent dosage, pH and salt on dye removal was evaluated. Adsorption kinetic of dyes followed pseudo-second order kinetics. The maximum dye adsorption capacity (Q{sub 0}) of PAIHP was 6667 mg/g, 5555 mg/g, 9090 mg/g and 5882 mg/g for DR31, DR23, DB22 and AB25, respectively. It was found that adsorption of DR31, DR23, DB22 and AB25 onto PAIHP followed with Langmuir isotherm. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% for DR31, 86% for DR23, 87% for DB22 and 90% for AB25 were achieved in aqueous solution at pH 12. The results showed that the PAIHP as a polymeric adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored wastewater.

  3. Differences in Learning Geometry among High and Low Spatial Ability Pre-Service Mathematics Teachers

    Science.gov (United States)

    Unal, Hasan; Jakubowski, Elizabeth; Corey, Darryl

    2009-01-01

    The objective of this study was to investigate and characterize the geometric thinking and understanding of four pre-service middle and secondary mathematics teachers while considering their spatial ability levels. To investigate the differences, if any, that existed among these pre-service middle and secondary teachers with different spatial…

  4. The Importance of Intrinsic Motivation for High and Low Ability Readers' Reading Comprehension Performance

    Science.gov (United States)

    Logan, Sarah; Medford, Emma; Hughes, Naomi

    2011-01-01

    The study examined how cognitive and motivational factors predicted reading skill and whether intrinsic reading motivation would explain significantly more variance in low ability readers' reading performance. One hundred and eleven children (aged 9-11) completed assessments of reading comprehension skill, verbal IQ, decoding skill and intrinsic…

  5. Do Peer Reviews Help Improve Student Writing Abilities in an EFL High School Classroom?

    Science.gov (United States)

    Kurihara, Noriko

    2017-01-01

    Several studies have reported the benefits of peer reviews in English as a second language (ESL) and English as a foreign language (EFL) writing classrooms. However, there has been little empirical research on whether such peer reviews improve students' writing abilities. The current study investigated the effects of peer review on the development…

  6. Improvement of The Ability of Junior High School Students Thinking Through Visual Learning Assisted Geo gbra Tutorial

    Science.gov (United States)

    Elvi, M.; Nurjanah

    2017-02-01

    This research is distributed on the issue of the lack of visual thinking ability is a must-have basic ability of students in learning geometry. The purpose of this research is to investigate and elucide: 1) the enhancement of visual thinking ability of students to acquire learning assisted with geogebra tutorial learning: 2) the increase in visual thinking ability of students who obtained a model of learning assisted with geogebra and students who obtained a regular study of KAM (high, medium, and low). This research population is grade VII in Bandung Junior High School. The instruments used to collect data in this study consisted of instruments of the test and the observation sheet. The data obtained were analyzed using the test average difference i.e. Test-t and ANOVA Test one line to two lines. The results showed that: 1) the attainment and enhancement of visual thinking ability of students to acquire learning assisted geogebra tutorial better than students who acquire learning; 2) there may be differences of visual upgrade thinking students who acquire the learning model assisted with geogebra tutorial earn regular learning of KAM (high, medium and low).

  7. Excessively High Vapor Pressure of Al-based Amorphous Alloys

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    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  8. The Intelligence of Observation: Improving High School Students' Spatial Ability by Means of Intervention Unit

    Science.gov (United States)

    Patkin, Dorit; Dayan, Ester

    2013-01-01

    This case study of one class versus a control group focused on the impact of an intervention unit, which is not part of the regular curriculum, on the improvement of spatial ability of high school students (forty-six 12th-graders, aged 17-18, both boys and girls) in general as well as from a gender perspective. The study explored three…

  9. Cultural and Social Capital and Talent Development: A Study of a High-Ability Aboriginal Student in a Remote Community

    Science.gov (United States)

    Kostenko, Karen; Merrotsy, Peter

    2009-01-01

    During the course of a school year, a study was conducted on the cultural context, the social milieu and the personal characteristics of a high ability Aboriginal student in a remote community in Canada. Using the lenses of cultural capital, social capital and human capital, the study explores the development of the student's talent through his…

  10. The Effects of a Social and Talent Development Intervention for High Ability Youth with Social Skill Difficulties

    Science.gov (United States)

    Foley-Nicpon, Megan; Assouline, Susan G.; Kivlighan, D. Martin; Fosenburg, Staci; Cederberg, Charles; Nanji, Michelle

    2017-01-01

    Contemporary models highlight the need to cultivate cognitive and psychosocial factors in developing domain-specific talent. This model was the basis for the current study where high ability youth with self-reported social difficulties (n = 28, 12 with a coexisting disability) participated in a social skills and talent development intervention…

  11. Intellectual Ability, Self-Perceived Social Competence, and Depressive Symptomatology in Children with High-Functioning Autistic Spectrum Disorders

    Science.gov (United States)

    Vickerstaff, Sandy; Heriot, Sandra; Wong, Michelle; Lopes, Ana; Dossetor, David

    2007-01-01

    Although social competence deficits in children with high-functioning autistic spectrum disorders (HFASD) are well documented, there is little research investigating self-perceptions of social limitations. This study replicated research showing a negative association between self-perceived social competence and intellectual ability and…

  12. Mobile Learning Based Worked Example in Electric Circuit (WEIEC) Application to Improve the High School Students' Electric Circuits Interpretation Ability

    Science.gov (United States)

    Yadiannur, Mitra; Supahar

    2017-01-01

    This research aims to determine the feasibility and effectivity of mobile learning based Worked Example in Electric Circuits (WEIEC) application in improving the high school students' electric circuits interpretation ability on Direct Current Circuits materials. The research method used was a combination of Four-D Models and ADDIE model. The…

  13. Differences and similarities in double special educational needs: high abilities/giftedness x Asperger’s Syndrome

    Directory of Open Access Journals (Sweden)

    Nara Joyce Wellausen Vieira

    2012-08-01

    Full Text Available The study was developed from a literature search in books, articles and theses that have been published since the year 2000 on the theme High Abilities / Giftedness and Asperger’s Syndrome. The objectives of this research were to conduct a search on publications from 2000 to 2011, about the common and different features to the person with Asperger syndrome and high ability gifted, and also relate the number of publications found in Education and Special Education. At theoretical we present the conception of High Abilities / Giftedness of Renzulli (2004 and Gardner (2000 and in the conception of Asperger Syndrome, Mello (2007 and Klin (2006. When analyzing the data, were perceived similarities and differences between the behavioral characteristics of individuals with High Abilities / Giftedness and those with Asperger’s Syndrome. It’s possible point out that there is much evidence that separate these two special educational needs and few similarities between them. But do not neglect that there may be a dual disability between these two particular special educational needs, because there are still few studies that verify theoretically the differences and similarities of these subjects, much less those that investigate these similarities and distinctions in the subjects themselves.

  14. Identifying High Ability Children with DSM-5 Autism Spectrum or Social Communication Disorder: Performance on Autism Diagnostic Instruments

    Science.gov (United States)

    Foley-Nicpon, Megan; Fosenburg, Staci L.; Wurster, Kristin G.; Assouline, Susan G.

    2017-01-01

    This study was a replication of Mazefsky et al.'s ("Journal of Autism and Developmental Disabilities" 43:1236-1242, 2013) investigation among a sample of 45 high ability children and adolescents diagnosed with ASD under DSM-IV-TR. Items from the ADOS and ADI-R were mapped onto DSM-5 diagnostic criteria for ASD and SCD to determine…

  15. Linguistic and other cognitive abilities in children with Specific Language Impairment as compared to children with High-Functioning Autism

    NARCIS (Netherlands)

    Schaeffer, J.

    2018-01-01

    This study investigates the question as to whether and how the linguistic and other cognitive abilities of children with Specific Language Impairment (SLI) differ from those of children with High-Functioning Autism (HFA). To this end, 27 Dutch-speaking elementary-school-age children with SLI, 27

  16. High performance cellulose nanocomposites: comparing the reinforcing ability of bacterial cellulose and nanofibrillated cellulose.

    Science.gov (United States)

    Lee, Koon-Yang; Tammelin, Tekla; Schulfter, Kerstin; Kiiskinen, Harri; Samela, Juha; Bismarck, Alexander

    2012-08-01

    This work investigates the surface and bulk properties of nanofibrillated cellulose (NFC) and bacterial cellulose (BC), as well as their reinforcing ability in polymer nanocomposites. BC possesses higher critical surface tension of 57 mN m(-1) compared to NFC (41 mN m(-1)). The thermal degradation temperature in both nitrogen and air atmosphere of BC was also found to be higher than that of NFC. These results are in good agreement with the higher crystallinity of BC as determined by XRD, measured to be 71% for BC as compared to NFC of 41%. Nanocellulose papers were prepared from BC and NFC. Both papers possessed similar tensile moduli and strengths of 12 GPa and 110 MPa, respectively. Nanocomposites were manufactured by impregnating the nanocellulose paper with an epoxy resin using vacuum assisted resin infusion. The cellulose reinforced epoxy nanocomposites had a stiffness and strength of approximately ∼8 GPa and ∼100 MPa at an equivalent fiber volume fraction of 60 vol.-%. In terms of the reinforcing ability of NFC and BC in a polymer matrix, no significant difference between NFC and BC was observed.

  17. CONNECTION OF TURN AHEAD AND TURN BACK WITH MOTORIC ABILITIES OF THE FOURTH GRADE OF HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Jovica Petković

    2008-08-01

    Full Text Available The research is done for the purpose of determination and defining of the level of connection between some motoric abilities with success in realization of programmed contents from the area of gymnastics (turn ahead and turn back. The research is done on the sample of fifty students from the fourth grade of High School, on ten motoric tests and on two specific motoric assignments – turn ahead and turn back. The results of this research clearly point that there exist the multitude of statistically important coefficients of correlation between treated motoric abilities and applied motoric assignments.

  18. Comparing Diagnostic Ability of Basic Emotional States in Children with High Performance Autism Disorder with Normal Peers

    Directory of Open Access Journals (Sweden)

    Fatemeh Jalili

    2012-04-01

    Full Text Available Background: Study on weaknesses and diagnostic strategies of autistic children in social interactions as well as how we can diagnose different emotions in the face may be an efficient step towards their therapy and communication improvement. The objective of this study was to compare diagnostic ability of basic emotions in children with high-performance autism with normal peers.Materials and Method: In this comparative profile study, two groups of 16 individuals: children with high-performance autistic disorder and their normal peers were selected by available sample method in terms of age, sex and life location. Neuropsychology diagnostic test of different emotions in Benton face (changed version was used to determine diagnostic ability of emotions (happy, sad and angry. Statistical analysis was performed using SPSS software and descriptive statistics and t-test were done for both independent groups.Results: Results showed that the ability of both tested groups is equal in diagnosing emotional states of joy, anger and neutral condition in face while viewing face picture and there was not any significant difference between groups but in diagnosing emotional grief state, the performance of autistics is lower and there was significant difference with normal peer group.Conclusion: The autistic children with high function are equal in ability with normal children in case of recognizing the happiness, anger and neutral facial excitement. However, they are less competent in recognizing the sadness and facial excitement than normal children

  19. Baseline Ability Makes a Larger Contribution to Race Performance in High-School Sprinters Than Race Experience or Training Exposure.

    Science.gov (United States)

    Lynch, Kristine E; Thomas, Alun; Gibson, Bryan

    2016-11-01

    There has long been a debate regarding the importance of talent versus training in athletic performance. In this study we sought to quantify their relative contributions to the race performance of high-school sprinters. Using race results from the athletic.net website, we identified high-school athletes who participated in at least one race in both 9th and 12th grade in the 100 m, 200 m or 400 m. Athletes with a record of racing before high school were excluded from the analyses. Using separate linear regression models for each event and gender, we analyzed the effect of baseline ability, race experience and training exposure on race time in the 12th grade. 35,909 athletes, running a total of 1,627,652 races, contributed to the final analyses. The proportion of variance (R2) in 12th grade race times accounted for by baseline ability ranged from 40% to 51% depending on the event, and was consistently higher for females than males. Race experience explained 3.6-4.4% of the variance and training exposure explained 0.8-1.7%. Although race experience and training exposure impact high-school sprinters' performance, baseline ability is the dominant influence.

  20. High-index-contrast grating reflector with beam steering ability for the transmitted beam

    DEFF Research Database (Denmark)

    Carletti, Luca; Malureanu, Radu; Mørk, Jesper

    2011-01-01

    High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derive....... Such grating mirrors would have a significant impact on low cost laser fabrication, since a more efficient integration of optoelectronic modules can be achieved by avoiding expensive external lens systems.......High-index contrast grating mirrors providing wave front control of the transmitted light as well as high reflectivity over a broad bandwidth are suggested and both numerically and experimentally investigated. General design rules to engineer these structures for different applications are derived...

  1. Teachers think differently: Method effects on the evaluation of high intellectual ability students’ socio–emotional intelligence

    Directory of Open Access Journals (Sweden)

    Daniel Hernández

    2011-10-01

    Full Text Available This paper investigates the relationship between 566 students’, their parents’ and their teachers’ perceptions on the socio–emotional competence of such sample of learners with high intellectual abilities. The results indicated that parents’ and their children’s self-perceptions were positively related, the relationship being moderately statistically significant in all socio–emotional intelligence aspects. However, the relationship between teachers’ ratings and parents’ and students’ ratings was positively statistically significant at a low level. Using a multitrait–multimethod analysis (Campbell and Fiske, 1959, the authors demonstrated strong method effects, especially in the case of teachers, indicating that ratings from different sources provide different and complementary information on the socio–emotional skills of high intellectual ability students.

  2. Syntactic and Story Structure Complexity in the Narratives of High- and Low-Language Ability Children with Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Eleni Peristeri

    2017-11-01

    Full Text Available Although language impairment is commonly associated with the autism spectrum disorder (ASD, the Diagnostic Statistical Manual no longer includes language impairment as a necessary component of an ASD diagnosis (American Psychiatric Association, 2013. However, children with ASD and no comorbid intellectual disability struggle with some aspects of language whose precise nature is still outstanding. Narratives have been extensively used as a tool to examine lexical and syntactic abilities, as well as pragmatic skills in children with ASD. This study contributes to this literature by investigating the narrative skills of 30 Greek-speaking children with ASD and normal non-verbal IQ, 16 with language skills in the upper end of the normal range (ASD-HL, and 14 in the lower end of the normal range (ASD-LL. The control group consisted of 15 age-matched typically-developing (TD children. Narrative performance was measured in terms of both microstructural and macrostructural properties. Microstructural properties included lexical and syntactic measures of complexity such as subordinate vs. coordinate clauses and types of subordinate clauses. Macrostructure was measured in terms of the diversity in the use of internal state terms (ISTs and story structure complexity, i.e., children's ability to produce important units of information that involve the setting, characters, events, and outcomes of the story, as well as the characters' thoughts and feelings. The findings demonstrate that high language ability and syntactic complexity pattern together in ASD children's narrative performance and that language ability compensates for autistic children's pragmatic deficit associated with the production of Theory of Mind-related ISTs. Nevertheless, both groups of children with ASD (high and low language ability scored lower than the TD controls in the production of Theory of Mind-unrelated ISTs, modifier clauses and story structure complexity.

  3. Syntactic and Story Structure Complexity in the Narratives of High- and Low-Language Ability Children with Autism Spectrum Disorder

    Science.gov (United States)

    Peristeri, Eleni; Andreou, Maria; Tsimpli, Ianthi M.

    2017-01-01

    Although language impairment is commonly associated with the autism spectrum disorder (ASD), the Diagnostic Statistical Manual no longer includes language impairment as a necessary component of an ASD diagnosis (American Psychiatric Association, 2013). However, children with ASD and no comorbid intellectual disability struggle with some aspects of language whose precise nature is still outstanding. Narratives have been extensively used as a tool to examine lexical and syntactic abilities, as well as pragmatic skills in children with ASD. This study contributes to this literature by investigating the narrative skills of 30 Greek-speaking children with ASD and normal non-verbal IQ, 16 with language skills in the upper end of the normal range (ASD-HL), and 14 in the lower end of the normal range (ASD-LL). The control group consisted of 15 age-matched typically-developing (TD) children. Narrative performance was measured in terms of both microstructural and macrostructural properties. Microstructural properties included lexical and syntactic measures of complexity such as subordinate vs. coordinate clauses and types of subordinate clauses. Macrostructure was measured in terms of the diversity in the use of internal state terms (ISTs) and story structure complexity, i.e., children's ability to produce important units of information that involve the setting, characters, events, and outcomes of the story, as well as the characters' thoughts and feelings. The findings demonstrate that high language ability and syntactic complexity pattern together in ASD children's narrative performance and that language ability compensates for autistic children's pragmatic deficit associated with the production of Theory of Mind-related ISTs. Nevertheless, both groups of children with ASD (high and low language ability) scored lower than the TD controls in the production of Theory of Mind-unrelated ISTs, modifier clauses and story structure complexity. PMID:29209258

  4. Syntactic and Story Structure Complexity in the Narratives of High- and Low-Language Ability Children with Autism Spectrum Disorder.

    Science.gov (United States)

    Peristeri, Eleni; Andreou, Maria; Tsimpli, Ianthi M

    2017-01-01

    Although language impairment is commonly associated with the autism spectrum disorder (ASD), the Diagnostic Statistical Manual no longer includes language impairment as a necessary component of an ASD diagnosis (American Psychiatric Association, 2013). However, children with ASD and no comorbid intellectual disability struggle with some aspects of language whose precise nature is still outstanding. Narratives have been extensively used as a tool to examine lexical and syntactic abilities, as well as pragmatic skills in children with ASD. This study contributes to this literature by investigating the narrative skills of 30 Greek-speaking children with ASD and normal non-verbal IQ, 16 with language skills in the upper end of the normal range (ASD-HL), and 14 in the lower end of the normal range (ASD-LL). The control group consisted of 15 age-matched typically-developing (TD) children. Narrative performance was measured in terms of both microstructural and macrostructural properties. Microstructural properties included lexical and syntactic measures of complexity such as subordinate vs. coordinate clauses and types of subordinate clauses. Macrostructure was measured in terms of the diversity in the use of internal state terms (ISTs) and story structure complexity, i.e., children's ability to produce important units of information that involve the setting, characters, events, and outcomes of the story, as well as the characters' thoughts and feelings. The findings demonstrate that high language ability and syntactic complexity pattern together in ASD children's narrative performance and that language ability compensates for autistic children's pragmatic deficit associated with the production of Theory of Mind-related ISTs. Nevertheless, both groups of children with ASD (high and low language ability) scored lower than the TD controls in the production of Theory of Mind-unrelated ISTs, modifier clauses and story structure complexity.

  5. Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

    OpenAIRE

    M.A. Kameli; M. Chorom; N. Jaafarzadeh; H. Janadeleh

    2017-01-01

    Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. S...

  6. Increased safety and tactical abilities of rescuers in liquidation of fires with high heat release

    Directory of Open Access Journals (Sweden)

    Тетяна Вікторівна Костенко

    2017-06-01

    Full Text Available Characteristic features of firefighters’ rescue work are risks for their lives because of possible explosions and collapses, danger of injuries, limited visual range or complete absence of visibility, high temperature and high humidity. Extinguishing fires in different weather conditions, the firefighters can be influenced by abrupt and repeated changes in ambient temperature. Close to the seat of fire the rescuer is exposed to powerful thermal radiation that makes it necessary to use personal individual thermal protection means. Fire units in Ukraine are equipped with heat-reflective and thermal protective suits, that have become outdated, with rather limited protective service life and don't ensure safety of firefighters during extinguishing fires and rescue operations under high temperature conditions. The drawbacks of these existing protective suits reduce the efficiency of the firefighters’ rescue work. That is why the improvement of individual thermal protection means will make it possible to increase the efficiency of work within the areas of high temperatures. The purpose of the work is to identify ways of upgrading the safety and tactical possibilities of emergency rescue operations under high temperature conditions. The article analyzes the working conditions of the rescuers, various types of thermal protection structural features and applying autonomic cooling elements, defines limiting values of heat flows and ambient air temperature. The surface layers of the protective clothing are of time and temperature limited utility. Analysis showed that the existing means of thermal protection are of limited usefulness and are too massive thus restraining the activities of firefighters. It has been concluded that it is possible to use water or foam forming composition from fire fighting systems for cooling the body and clothes of the rescuers. Following these recommendations may increase the tactical possibilities of rescue units in

  7. Ability, Parental Valuation of Education and the High School Dropout Decision

    DEFF Research Database (Denmark)

    Foley, Kelly; Gallipoli, Giovanni; Green, David

    that teenage boys with two parents who are themselves high school dropouts have a 16% chance of dropping out, compared to a dropout rate of less than 1% for boys whose parents both have a university degree. We examine the channels through which this socio-economic gradient arises using an extended version......We use a large, rich Canadian micro-level dataset to examine the channels through which family socio-economic status and unobservable characteristics a ect children's decisions to drop out of high school. First, we document the strength of observable socio-economic factors: our data suggest...

  8. A class-A GPCR solubilized under high hydrostatic pressure retains its ligand binding ability

    Science.gov (United States)

    The effect of high hydrostatic pressure (HHP) on the solubilization of a class-A G protein-coupled receptor, the silkmoth pheromone biosynthesis-activating neuropeptide receptor (PBANR), was investigated. PBANR was expressed in expresSF+ insect cells as a C-terminal fusion protein with EGFP. The mem...

  9. High-demand jobs: age-related diversity in work ability?

    NARCIS (Netherlands)

    Sluiter, Judith K.

    2006-01-01

    High-demand jobs include 'specific' job demands that are not preventable with state of the art ergonomics knowledge and may overburden the bodily capacities, safety or health of workers. An interesting question is whether the age of the worker is an important factor in explanations of diversity in

  10. The ability of Typha domingensis to accumulate and tolerate high concentrations of Cr, Ni, and Zn.

    Science.gov (United States)

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2015-01-01

    The tolerance and removal efficiency of Typha domingensis exposed to high concentrations of Cr, Ni, and Zn in single and combined treatments were studied. Sediment and two plants were disposed in each plastic reactor. The treatments were 100 and 500 mg L(-1) of Cr, Ni, and Zn (single solutions); 100 mg L(-1) Cr + Ni + Zn (multi-metal solutions) and 500 mg L(-1) Cr + Ni + Zn (multi-metal solutions); and a control. Even though the concentrations studied were extremely high, simulating an accidental metal dump, the three metals were efficiently removed from water. The highest removal was registered for Cr. The presence of other metals favored Cr and did not favor Ni and Zn removal from water. After 25 days, senescence and chlorosis of plants were observed in Ni and Comb500 treatments, while Cr and Zn only caused growth inhibition. T. domingensis accumulated high metal concentrations in tissues. The roots showed higher metal concentration than submerged parts of leaves. Cr translocation to aerial parts was enhanced by the presence of Ni and Zn. Our results demonstrate that in the case of an accidental dump of high Cr, Ni, and Zn concentrations, a wetland system dominated by T. domingensis is able to retain metals, and the macrophyte is able to tolerate them the time necessary to remove them from water. Thus, the environment will be preserved since the wetland would act as a cushion.

  11. Rorschach interpretation with high-ability adolescent females: psychopathology or creative thinking?

    Science.gov (United States)

    Franklin, K W; Cornell, D G

    1997-02-01

    Highly intelligent and creative persons have long posed interpretation difficulties for users of the Rorschach Inkblot Test. This study examined Exner's (1993) Schizophrenia, Depression, and Coping Deficit indices as adjustment measures in a sample of 43 female adolescents enrolled in an early college entrance program and a comparison group of 19 girls enrolled in public high school gifted programs. Contrary to conventional interpretation, higher scores on the Rorschach Schizophrenia Index among the accelerants were correlated with healthy emotional adjustment on both the California Psychological Inventory and the Self-Perception Profile for Adolescents (SPPA). Further analyses offered support for the hypothesis that among accelerants, elevated scores on the Rorschach constellations did not indicate psychopathology, but rather their creative thinking style.

  12. High phosphate reduces host ability to develop arbuscular mycorrhizal symbiosis without affecting root calcium spiking responses to the fungus

    Directory of Open Access Journals (Sweden)

    Coline eBalzergue

    2013-10-01

    Full Text Available The arbuscular mycorrhizal symbiosis associates soil fungi with the roots of the majority of plants species and represents a major source of soil phosphorus acquisition. Mycorrhizal interactions begin with an exchange of molecular signals between the two partners. A root signaling pathway is recruited, for which the perception of fungal signals triggers oscillations of intracellular calcium concentration. High phosphate availability is known to inhibit the establishment and/or persistence of this symbiosis, thereby favoring the direct, non symbiotic uptake of phosphorus by the root system. In this study, Medicago truncatula plants were used to investigate the effects of phosphate supply on the early stages of the interaction. When plants were supplied with high phosphate fungal attachment to the roots was drastically reduced. An experimental system was designed to individually study the effects of phosphate supply on the fungus, on the roots and on root exudates. These experiments revealed that the most important effects of high phosphate supply were on the roots themselves, which became unable to host mycorrhizal fungi even when these had been appropriately stimulated. The ability of the roots to perceive their fungal partner was then investigated by monitoring nuclear calcium spiking in response to fungal signals. This response did not appear to be affected by high phosphate supply. In conclusion, high levels of phosphate predominantly impact the plant host, but apparently not in its ability to perceive the fungal partner.

  13. Multiplexed polarization OTDR system with high DOP and ability of multi-event detection.

    Science.gov (United States)

    Wang, Xuefeng; Wang, Chaodong; Tang, Ming; Fu, Songnian; Shum, Perry

    2017-05-01

    A novel polarization optical time domain reflectometry (POTDR) with high degree of polarization is proposed for multi-event detection. By employing multiple 2×2 optical fiber couplers and fiber mirrors, an arbitrary number and customized length of sensing fiber can be multiplexed into the system without modification of the other components, e.g., the light source, photodetector, signal processing device, etc. More importantly, the signal-to-noise ratio of this system is significantly improved, and the temporal depolarization effect can be almost completely suppressed. Additionally, the system response time is considerably reduced by dispensing with data averaging, so that intrusion events such as touching and moving fiber can be detected instantaneously and precisely located. Experiments have been conducted that proved the capability of multi-event simultaneous detection and vibration frequency measurement. This system promises application potential in multi-zone perimeter security and physical field measurement.

  14. Plasmid size can affect the ability of Escherichia coli to produce high-quality plasmids.

    Science.gov (United States)

    Yang, Junlin; Yang, Yong

    2012-11-01

    Large molecular weight plasmids are often used in gene therapy and DNA vaccines. To investigate the effect of plasmid size on the performance of Escherichia coli host strains during plasmid preparation, we employed E. coli JM109 and TOP10 cells to prepare four plasmids ranging from 4.7 to 16.8 kb in size. Each plasmid was extracted from JM109 and TOP10 cells using an alkaline lysis mini-preparation method. However, when commercial kits were used to extract the same plasmids from JM109 cells, the large molecular weight plasmids substantially degraded, compared with their smaller counterparts. No degradation was observed when the four plasmids were extracted from E. coli TOP10 cells using the same commercial kit. We conclude, therefore, that the performance of E. coli in high quality plasmid preparations can be affected by plasmid size.

  15. Short Circuits or Superconductors? Examining Factors That Encourage or Undermine Group Learning and Collaboration among High-Ability Students. CSE Technical Report.

    Science.gov (United States)

    Webb, Noreen M.; Welner, Mari; Zuniga, Stephen

    This study investigated the effects of group ability composition (homogeneous versus heterogeneous) on group processes and outcomes for high ability students completing science performance assessments. Participants were 99 seventh and eighth graders from 9 classes in 2 schools. The results show that group ability composition does not have…

  16. Fostering Creativity in the Classroom for High Ability Students: Context Does Matter

    Directory of Open Access Journals (Sweden)

    Liang See Tan

    2016-11-01

    Full Text Available Researchers have argued for the importance of the classroom context in developing students’ creative potential. However, the emphasis on a performative learning culture in the classroom does not favour creativity. Thus, how creative potential can be realised as one of the educational goals in the classrooms remains a key question. This study measured creativity across three secondary schools using the Wallach-Kogan Creative Thinking Test (WKCT. A total of 283 students enrolled in the Express programme and 290 students enrolled in the Integrated Programme (IP volunteered in the study. The same cohort of students took the 38-item WKCT twice; once at the beginning of Secondary One and then at the end of Secondary Three. Four aspects of creativity, namely fluency, flexibility, unusualness, and uniqueness, were investigated. Our analyses showed that (i IP students showed a greater increase in scores over time when compared to Express students; (ii when Programme and PSLE (Primary School Leaving Examination were used to predict creativity scores in a multiple regression, the predictive power of Programme increased from Secondary 1 to Secondary 3 while that of PSLE decreased; and (iii flexibility scores were more resistant to change than fluency scores. These findings suggest that the classroom context matters and that the removal of high-stakes examination can provide room for the development of creative potential.

  17. High embryogenic ability and regeneration from floral axis of Amorphophallus konjac (Araceae

    Directory of Open Access Journals (Sweden)

    Zhong Lin

    2017-03-01

    Full Text Available Amorphophallus konjac (Araceae a perennial herb, it has high medicinal and industrial value. In this study, a simple and efficient system for direct somatic embryogenesis and plantlet regeneration of Amorphophallus konjac was developed. The floral axis was used as the experimental material. The primary callus, developed from the floral axis grown on Murashige and Skoog (MS medium supplemented with different hormone combination at different concentrations. The highest rate of embryogenic callus formation was observed on the MS medium containing 9.04 µM 2, 4-dichlorophenoxyacetic acid (2, 4-D and 5.37 µM naphthalene acetic acid (NAA. The maximum induction rate was 79.8%, and the embryogenic calli were able to subculture on a medium containing similar hormone combination for over 1 year. The calli were also placed on different media for regeneration and it produced complete plants with shoots and root systems simultaneously. The highest differentiation rate of the embryogenic calli grown on differentiation medium supplemented with 8.88 µM 6-benzylaminopurine (6-BA and 5.37 µM NAA was 95.6%. Flow cytometry analysis showed no ploidy variation in all the regenerate plantlets.

  18. A silver fluoniobate semiconductor with high photo-oxidization abilities and photocatalytic activities

    Science.gov (United States)

    Huang, Yanlin; Cao, Lei; Feng, Yongyi; Qin, Chuanxiang; Seo, Hyo Jin

    2017-11-01

    In the past years, nano-sized Nb2O5 has been widely as a potential photocatalyst due to its good chemical stability and higher conduction band edge than TiO2. However, the photocatalytic application of Nb2O5 is limited by vide band gap (3.4-4 eV) because only UV light could be harvested. In this work, Nb2O5-based photocatalyst, AgNb2O5F, was developed by solid-state reaction. The phase formation and surface characteristics were investigated. AgNb2O5F has a direct allowed transition with band energy of 2.68 eV. It has a highly positive valence band. The photocatalysis degradation of MB solutions by Nb2O5 is less than 10% after the light irradiation (λ > 420 nm) in 120 min. AgNb2O5F shows a rapid degradation, which is 83% under the same conditions. AgNb2O5F presents more efficient degradation of organic dyes than Nb2O5. This semiconductor also keeps stabilities for photo-corrosions and photo-degradation reactions. The photocatalytic activities were discussed on the luminescence and decay lifetimes.

  19. The identification of high potential archers based on fitness and motor ability variables: A Support Vector Machine approach.

    Science.gov (United States)

    Taha, Zahari; Musa, Rabiu Muazu; P P Abdul Majeed, Anwar; Alim, Muhammad Muaz; Abdullah, Mohamad Razali

    2018-02-01

    Support Vector Machine (SVM) has been shown to be an effective learning algorithm for classification and prediction. However, the application of SVM for prediction and classification in specific sport has rarely been used to quantify/discriminate low and high-performance athletes. The present study classified and predicted high and low-potential archers from a set of fitness and motor ability variables trained on different SVMs kernel algorithms. 50 youth archers with the mean age and standard deviation of 17.0 ± 0.6 years drawn from various archery programmes completed a six arrows shooting score test. Standard fitness and ability measurements namely hand grip, vertical jump, standing broad jump, static balance, upper muscle strength and the core muscle strength were also recorded. Hierarchical agglomerative cluster analysis (HACA) was used to cluster the archers based on the performance variables tested. SVM models with linear, quadratic, cubic, fine RBF, medium RBF, as well as the coarse RBF kernel functions, were trained based on the measured performance variables. The HACA clustered the archers into high-potential archers (HPA) and low-potential archers (LPA), respectively. The linear, quadratic, cubic, as well as the medium RBF kernel functions models, demonstrated reasonably excellent classification accuracy of 97.5% and 2.5% error rate for the prediction of the HPA and the LPA. The findings of this investigation can be valuable to coaches and sports managers to recognise high potential athletes from a combination of the selected few measured fitness and motor ability performance variables examined which would consequently save cost, time and effort during talent identification programme. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The high tolerance to aluminium in crucian carp (Carassius carassius) is associated with its ability to avoid hypoxia.

    Science.gov (United States)

    Poléo, Antonio B S; Schjolden, Joachim; Sørensen, Jørgen; Nilsson, Göran E

    2017-01-01

    It is well known that aluminium is the principle toxicant killing fish in acidified freshwater systems, and it has been shown that crucian carp (Carassius carassius) can survive exposures to aqueous aluminium levels toxic to most other freshwater fish species. The crucian carp has a remarkable ability to survive anoxic conditions, and the aim of the present study was to reveal if the tolerance to aluminium can be associated with the ability to survive prolonged anoxia. Crucian carps were exposed to either acidic Al-rich water (pH 5.8; 960 μg Al/l), acidic Al-poor water (pH 5.8; 50 μg Al/l) or untreated control water (pH 6.5; 50 μg Al/l). Blood, muscle and gill samples were collected from exposed fish, and closed respirometry was performed to measure critical O2-tension an normoxic O2-consumption. The results show an increased gill surface area in Al-exposed fish, while the critical O2-tension did not change. The normoxic O2-consumption was lower in Al-exposed fish and might be due to a reduced metabolic rate. The results suggest that crucian carp exposed to aluminium do not become hypoxic, since haematocrit, plasma lactate and blood ethanol did not differ from that of control fish after 14 days of exposure. We also observed an initial loss of plasma chloride and sodium, followed by a stabilisation of these ions at a lower level than in control fish. The decrease in plasma ions caused a transient increase in haematocrit and water content in muscle tissue, returning to control levels when the ion concentrations stabilised, suggesting that the water balance was restored. We conclude that the high tolerance to aluminium in crucian carp is associated with its ability to avoid hypoxia as well as an ability to counteract a continuous loss of plasma ions.

  1. Improving Junior High School Students' Spatial Reasoning Ability through Model Eliciting Activities with Cabri 3D

    Science.gov (United States)

    Hartatiana; Darhim; Nurlaelah, Elah

    2018-01-01

    One of students' abilities which can facilitate them to understand geometric concepts is spatial reasoning ability. Spatial reasoning ability can be defined as an ability involving someone's cognitive processing to present and manipulate spatial figures, relationship, and figure formations. This research aims to find out significant difference on…

  2. Physicians' assessments of their ability to provide high-quality care in a changing health care system.

    Science.gov (United States)

    Reschovsky, J; Reed, M; Blumenthal, D; Landon, B

    2001-03-01

    With the growth of managed care, there are increasing concerns but inconclusive evidence regarding deterioration in the quality of medical care. To assess physicians' perceptions of their ability to provide high-quality care and explore what factors, including managed care, affect these perceptions. Bivariate and multivariate analyses of the Community Tracking Study Physician Survey, a cross-sectional, nationally representative telephone survey of 12,385 patient-care physicians conducted in 1996/1997. The response rate was 65%. Physicians who provide direct patient care for > or =20 h/wk, excluding federal employees and those in selected specialties. Level of agreement with 4 statements: 1 regarding overall ability to provide high-quality care and 3 regarding aspects of care delivery associated with quality. Between 21% and 31% of physicians disagreed with the quality statements. Specialists were generally 50% more likely than primary care physicians to express concerns about their ability to provide quality care. Generally, the number of managed care contracts, but not the percent of practice revenue from managed care, was negatively associated with perceived quality. Market-level managed care penetration independently affected physicians' perceptions. Practice setting affected perceptions of quality, with physicians in group settings less likely to express concerns than physicians in solo and 2-physician practices. Specific financial incentives and care management tools had limited positive or negative associations with perceived quality. Managed care involvement is only modestly associated with reduced perceptions of quality among physicians, with some specific tools enhancing perceived quality. Physicians may be able to moderate some negative effects of managed care by altering their practice arrangements.

  3. Sports genetics: the PPARA gene and athletes' high ability in endurance sports. A systematic review and meta-analysis.

    Science.gov (United States)

    Lopez-Leon, S; Tuvblad, C; Forero, D A

    2016-03-01

    A meta-analysis was performed with the aim of re-evaluating the role of the peroxisome proliferator activated receptor alpha (PPARA) gene intron 7 G/C polymorphism (rs4253778) in athletes' high ability in endurance sports. A meta-analysis of case control studies assessing the association between the G/C polymorphisms of the PPARA gene and endurance sports was conducted. The Cochrane Review Manager software was used to compare the genotype and allele frequencies between endurance athletes and controls to determine whether a genetic variant is more common in athletes than in the general population. Five studies, encompassing 760 endurance athletes and 1792 controls, fulfilled our inclusion criteria. The pooled odds ratio (and confidence intervals, CIs) for the G allele compared to the C allele was 1.65 (95% CI 1.39-1.96). The pooled OR for the GG genotype compared to the GC genotype was 1.79 (95% CI 1.44-2.22), and for the GG genotype compared to the CC genotype 2.37 (95% CI 1.40-3.99). There was no evidence of heterogeneity (I(2) =0%) or of publication bias. Athletes with high ability in endurance sports had a higher frequency of the GG genotype and G allele.

  4. Sports genetics: the PPARA gene and athletes’ high ability in endurance sports. A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    S Lopez-Leon

    2016-01-01

    Full Text Available A meta-analysis was performed with the aim of re-evaluating the role of the peroxisome proliferator activated receptor alpha ( PPARA gene intron 7 G/C polymorphism (rs4253778 in athletes‘ high ability in endurance sports. Design: A meta-analysis of case control studies assessing the association between the G/C polymorphisms of the PPARA gene and endurance sports was conducted. The Cochrane Review Manager software was used to compare the genotype and allele frequencies between endurance athletes and controls to determine whether a genetic variant is more common in athletes than in the general population. Five studies, encompassing 760 endurance athletes and 1792 controls, fulfilled our inclusion criteria. The pooled odds ratio (and confidence intervals, Cls for the G allele compared to the C allele was 1.65 (95% Cl 1.39-1.96. The pooled OR for the GG genotype compared to the GC genotype was 1.79 (95% Cl 1.44-2.22, and for the GG genotype compared to the CC genotype 2.37 (95% Cl 1.40-3.99. There was no evidence of heterogeneity (I1 =0“/n or of publication bias. Athletes with high ability in endurance sports had a higher frequency of the GG genotype and G allele.

  5. Social and Affective Concerns High-Ability Adolescents Indicate They Would Like to Discuss with a Caring Adult: Implications for Educators

    Science.gov (United States)

    Jen, Enyi; Wu, Jiaxi; Gentry, Marcia

    2016-01-01

    This exploratory study investigated the social and affective concerns of 280 high-ability students in Grades 5 through 12 who participated in a summer residential program. Content analysis of responses from an open-ended survey indicated that high-ability adolescents expressed concerns regarding feelings and emotions, future aspirations, and…

  6. The effectiveness of high fidelity simulation on medical-surgical registered nurses' ability to recognise and respond to clinical emergencies.

    Science.gov (United States)

    Buckley, Thomas; Gordon, Christopher

    2011-10-01

    There is a paucity of evidence regarding the efficacy in preparing medical-surgical nurses to respond to patients with acutely deteriorating conditions. The aim of this study was to evaluate registered nurses' ability to respond to the deteriorating patient in clinical practise following training using immersive simulation and use of a high fidelity simulator. This study was a follow-up survey of medical-surgical graduate nurses following immersive high fidelity simulation training. Thirty eight registered nurses practising in medical-surgical areas completed the simulation as part of university graduate study. A follow-up survey of the graduate medical-surgical registered nurses conducted three months following completion of a high fidelity simulation-based learning experience. Outcomes consisted of the number of times skills were used in practise and the usefulness of simulation in preparing for actual emergency events. Participants reported a total of 164 clinical patient emergencies in the follow-up time period including: 46% cardiac, 32% respiratory, 10% neurological, 7% cardiac arrest and 5% related to electrolyte disturbances. The ability to respond in a systematic way, handover to the emergency team and airway management were identified as the skills most improved during patient emergencies following simulation. The most useful aspects of the simulation experience identified were scenario debriefing and assertiveness training. Participants with less years of clinical experience were more likely to report practising the team leader role and debriefing as the most useful aspects of simulation. The skills practised in simulation were highly relevant to participants practise in medical-surgical areas. Non-technical skills, including assertiveness skills should be considered in future emergency training courses for nurses. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Topology of genetic associations between regional gray matter volume and intellectual ability: Evidence for a high capacity network.

    Science.gov (United States)

    Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Hedman, Anna M; van den Heuvel, Martijn P; van Haren, Neeltje E M; Kahn, René S; Hulshoff Pol, Hilleke E

    2016-01-01

    Intelligence is associated with a network of distributed gray matter areas including the frontal and parietal higher association cortices and primary processing areas of the temporal and occipital lobes. Efficient information transfer between gray matter regions implicated in intelligence is thought to be critical for this trait to emerge. Genetic factors implicated in intelligence and gray matter may promote a high capacity for information transfer. Whether these genetic factors act globally or on local gray matter areas separately is not known. Brain maps of phenotypic and genetic associations between gray matter volume and intelligence were made using structural equation modeling of 3T MRI T1-weighted scans acquired in 167 adult twins of the newly acquired U-TWIN cohort. Subsequently, structural connectivity analyses (DTI) were performed to test the hypothesis that gray matter regions associated with intellectual ability form a densely connected core. Gray matter regions associated with intellectual ability were situated in the right prefrontal, bilateral temporal, bilateral parietal, right occipital and subcortical regions. Regions implicated in intelligence had high structural connectivity density compared to 10,000 reference networks (p=0.031). The genetic association with intelligence was for 39% explained by a genetic source unique to these regions (independent of total brain volume), this source specifically implicated the right supramarginal gyrus. Using a twin design, we show that intelligence is genetically represented in a spatially distributed and densely connected network of gray matter regions providing a high capacity infrastructure. Although genes for intelligence have overlap with those for total brain volume, we present evidence that there are genes for intelligence that act specifically on the subset of brain areas that form an efficient brain network. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Organic-inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency.

    Science.gov (United States)

    Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

    2018-03-02

    Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO 3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

  9. Organic–inorganic hybrid optical foils with strong visible reflection, excellent near infrared-shielding ability and high transparency

    Science.gov (United States)

    Zhou, Yijie; Huang, Aibin; Zhou, Huaijuan; Ji, Shidong; Jin, Ping

    2018-03-01

    Research on functional flexible films has recently been attracting widespread attention especially with regards to foils, which can be designed artificially on the basis of the practical requirements. In this work, a foil with high visible reflection and a strong near infrared shielding efficiency was prepared by a simple wet chemical method. In the process of making this kind of optical foil, emulsion polymerization was first introduced to synthesize polymer opals, which were further compressed between two pieces of polyethylene terephthalate (PET) foil under polymer melting temperature to obtain a photonic crystal film with a strong reflection in the visible region to block blue rays. The following step was to coat a layer of the inorganic nano paint, which was synthesized by dispersing Cs-doped WO3 (CWO) nanoparticles homogenously into organic resin on the surface of the PET to achieve a high near infrared shielding ability. The final composite foil exhibited unique optical properties such as high visible reflectance (23.9%) to block blue rays, and excellent near infrared shielding efficiency (98.0%), meanwhile it still maintained a high transparency meaning that this foil could potentially be applied in energy-saving window films. To sum up, this study provides new insight into devising flexible hybrid films with novel optical properties, which could be further extended to prepare other optical films for potential use in automobile, architectural and other decorative fields.

  10. Acquisition of useful and high ability genes for acidophilic bacteria; Kosansei saikin ni takai noryoku wo fuyosuru idenshi no kakutoku

    Energy Technology Data Exchange (ETDEWEB)

    Senda, T.; Inoue, C.; Shinbori, Y. [Tohoku University, Sendai (Japan)

    1997-02-01

    This effort aims at the development of high-performance bacteria usable in bio-leaching in metal smelting by acquiring genes capable of realizing such. A method is used of choosing some isolated strains exhibiting high-performance traits and acquiring target genes therefrom by use of genetic engineering. Approximately 200 kinds in the aggregate of acidophilic bacteria are currently available for the study, including isolated iron-oxidizing and sulfur-oxidizing bacteria, standard species acquired for the study, and strains previously isolated by the laboratory. The bacteria are tested with respect to their Fe{sup 2+}-oxidizing rates, sulfur-oxidizing capabilities, and strength to withstand inhibiting substances (Ag{sup +}, Cl{sup -}, Mo{sup 6+}, etc.), which results in the nomination of 8 strains. The study planned to follow includes processes involving the extraction of chromosome DNAs from the 8 strains and their refinement, gene cloning by the Southern hybridization method, determination of their base sequences, determination of the difference between the strains in point of gene expression, and investigations of the relations that the results of these processes bear toward the said high-performance traits. Also under way is a study about the infuence-exerting factors revealed during the evaluation of the abilities of acidphlic bacteria. 2 refs., 2 tabs.

  11. I've Fallen and I Can't Get up: Can High-Ability Students Recover from Early Mistakes in CAT?

    Science.gov (United States)

    Rulison, Kelly L.; Loken, Eric

    2009-01-01

    A difficult result to interpret in Computerized Adaptive Tests (CATs) occurs when an ability estimate initially drops and then ascends continuously until the test ends, suggesting that the true ability may be higher than implied by the final estimate. This study explains why this asymmetry occurs and shows that early mistakes by high-ability…

  12. The Development of Learning Devices Based Guided Discovery Model to Improve Understanding Concept and Critical Thinking Mathematically Ability of Students at Islamic Junior High School of Medan

    Science.gov (United States)

    Yuliani, Kiki; Saragih, Sahat

    2015-01-01

    The purpose of this research was to: 1) development of learning devices based guided discovery model in improving of understanding concept and critical thinking mathematically ability of students at Islamic Junior High School; 2) describe improvement understanding concept and critical thinking mathematically ability of students at MTs by using…

  13. Sensory Processing Abilities and Their Relation to Participation in Leisure Activities among Children with High-Functioning Autism Spectrum Disorder (HFASD)

    Science.gov (United States)

    Hochhauser, Michal; Engel-Yeger, Batya

    2010-01-01

    Children with autism may have atypical sensory processing abilities, which are known to impact child's performance and participation. However, lack of information exists regarding the expression of these abilities in specific groups on the spectrum, as children with high-functioning autism spectrum disorder (HFASD). This study aimed to…

  14. Emotion Perception Mediates the Predictive Relationship between Verbal Ability and Functional Outcome in High-Functioning Adults with Autism Spectrum Disorder

    Science.gov (United States)

    Otsuka, Sadao; Uono, Shota; Yoshimura, Sayaka; Zhao, Shuo; Toichi, Motomi

    2017-01-01

    The aim of this study was to identify specific cognitive abilities that predict functional outcome in high-functioning adults with autism spectrum disorder (ASD), and to clarify the contribution of those abilities and their relationships. In total, 41 adults with ASD performed cognitive tasks in a broad range of neuro- and social cognitive…

  15. Do asymptomatic former high-impact sports practitioners maintain the ability to contract the pelvic floor muscles?

    Science.gov (United States)

    Brandão, S; Da Roza, T; Mascarenhas, T; Ramos, I; Natal Jorge, R

    2015-11-01

    Sports are associated with pelvic floor dysfunction. This work aimed to assess, in nulliparous asymptomatic women, whether previous intense practice of high-impact sports is associated with differences in morphology and contraction of the pelvic floor muscles, when compared to women who practiced low-level physical activity. In this prospective pilot study, 7 former high-impact sports practitioners and a control group (N.=7) were compared. Clinical evaluation and self-administered questionnaires were used to gather information about pelvic floor dysfunction and physical activity. Static and cine dynamic MR images were acquired. Morphological measures of the pubovisceral muscle area and thickness, and levator hiatus (LH) anterior-to-posterior diameter, width and area were taken in the static images. LH anterior-to-posterior diameter was again assessed in the dynamic acquisition (consecutive blocks of rest vs. maximal voluntary contraction). The relative variation between these two conditions was used as an indirect measure of contraction. No abnormal clinical or imaging findings were reported. Former high-impact sports practitioners evidenced decreased pubovisceral muscle thickness (right side P=0.005; left side P=0.004) and area (P=0.004), and larger levator hiatus width and area (P=0.045; P=0.005). Only its anterior-to-posterior diameter was similar (4.89cm±0.35 and 4.81cm±0.17, respectively). Their ability to perform maximum voluntary contractions seems to have decreased (8.03%±0.81 vs. 13.74%±0.95 for controls). The current results suggest that women who previously practiced high-impact sports, even being asymptomatic, may have suffered damage to the pelvic floor muscles due to the biomechanical impact of the sports. They may require pelvic floor muscle training to increase muscle thickness and hiatal closing capacity.

  16. Mathematics Instructional Model Based on Realistic Mathematics Education to Promote Problem Solving Ability at Junior High School Padang

    Directory of Open Access Journals (Sweden)

    Edwin Musdi

    2016-02-01

    Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase.  At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.

  17. Response of complex networks to compression: Ca, La, and Y aluminoborosilicate glasses formed from liquids at 1 to 3 GPa pressures

    Energy Technology Data Exchange (ETDEWEB)

    Bista, Saurav, E-mail: sbista@stanford.edu; Stebbins, Jonathan F. [Department of Geological Sciences, Stanford University, Stanford, California 94305 (United States); Morin, Elizabeth I. [Department of Chemistry, Stanford University, Stanford, California 94305 (United States)

    2016-01-28

    Aluminoborosilicate glasses containing relatively high field strength modifiers (Ca, La, and Y) have been compressed at pressures up to 3 GPa and near the glass transition temperature (T{sub g}) and quenched to room temperature at high pressure followed by decompression. Structural changes were quantified with high-resolution {sup 27}Al and {sup 11}B MAS nuclear magnetic resonance at 14.1–18.8 T. The changes with pressure in Al and B coordinations in the recovered samples are quite large with more than 50% decreases in tetrahedral aluminum ({sup IV}Al) and 200%-300% increases in tetrahedral boron ({sup IV}B). Glasses with higher field strength modifiers (La and Y) contain more high coordinated aluminum ({sup V,V} {sup I}Al) at all pressures studied. More high coordinated boron also correlates with higher field strength modifier if all three compositions are compared on an isothermal basis. Although lowering fictive temperature and increasing pressure both increase Al and B coordinations, our study shows that the actual mechanisms for structural changes are most probably different for temperature and pressure effects. Using a rough thermodynamic model to extrapolate to higher pressures, it appears that a simple non-bridging oxygen (NBO) consumption mechanism is not sufficient to convert all the aluminum to octahedral and boron to tetrahedral coordination, suggesting other mechanisms for structural changes could occur at high pressure as NBO becomes depleted.

  18. I’ve Fallen and I Can’t Get Up: Can High Ability Students Recover From Early Mistakes in CAT?

    Science.gov (United States)

    Rulison, Kelly L.; Loken, Eric

    2010-01-01

    A difficult result to interpret in Computerized Adaptive Tests (CATs) occurs when an ability estimate initially drops and then ascends continuously until the test ends, suggesting that the true ability may be higher than implied by the final estimate. We explain why this asymmetry occurs and show that early mistakes by high ability students can lead to considerable underestimation, even in tests with 45 items. The opposite response pattern, where low ability students start with lucky guesses, leads to much less bias. We show that using Barton and Lord’s (1981) four-parameter model and a less informative prior can lower bias and RMSE for high ability students with a poor start, as the CAT algorithm ascends more quickly after initial underperformance. We also show that the 4PM slightly outperforms a CAT in which less discriminating items are initially used. The practical implications and relevance for psychological measurement more generally are discussed. PMID:20953275

  19. I've Fallen and I Can't Get Up: Can High Ability Students Recover From Early Mistakes in CAT?

    Science.gov (United States)

    Rulison, Kelly L; Loken, Eric

    2009-03-01

    A difficult result to interpret in Computerized Adaptive Tests (CATs) occurs when an ability estimate initially drops and then ascends continuously until the test ends, suggesting that the true ability may be higher than implied by the final estimate. We explain why this asymmetry occurs and show that early mistakes by high ability students can lead to considerable underestimation, even in tests with 45 items. The opposite response pattern, where low ability students start with lucky guesses, leads to much less bias. We show that using Barton and Lord's (1981) four-parameter model and a less informative prior can lower bias and RMSE for high ability students with a poor start, as the CAT algorithm ascends more quickly after initial underperformance. We also show that the 4PM slightly outperforms a CAT in which less discriminating items are initially used. The practical implications and relevance for psychological measurement more generally are discussed.

  20. The Relationship between Chinese High School Students' Implicit Theories of Ability in Sports and Perceived Enjoyment in Physical Education

    Science.gov (United States)

    Zhao, Qi; Li, Weidong

    2016-01-01

    According to theory, students' implicit theories of ability can affect their motivation and engagement in physical education (PE). Limited research has been conducted to examine the relationships between implicit theories of ability and motivation and engagement among K-12 students in PE. Our study examined the relationship between implicit…

  1. Mathematical Problem Solving Ability of Junior High School Students through Ang’s Framework for Mathematical Modelling Instruction

    Science.gov (United States)

    Fasni, N.; Turmudi, T.; Kusnandi, K.

    2017-09-01

    This research background of this research is the importance of student problem solving abilities. The purpose of this study is to find out whether there are differences in the ability to solve mathematical problems between students who have learned mathematics using Ang’s Framework for Mathematical Modelling Instruction (AFFMMI) and students who have learned using scientific approach (SA). The method used in this research is a quasi-experimental method with pretest-postest control group design. Data analysis of mathematical problem solving ability using Indepent Sample Test. The results showed that there was a difference in the ability to solve mathematical problems between students who received learning with Ang’s Framework for Mathematical Modelling Instruction and students who received learning with a scientific approach. AFFMMI focuses on mathematical modeling. This modeling allows students to solve problems. The use of AFFMMI is able to improve the solving ability.

  2. In vitro study of anti-suck-back ability by themselves on new high-speed air turbine handpieces.

    Science.gov (United States)

    Ozawa, Toshiko; Nakano, Masako; Arai, Takashi

    2010-11-01

    The anti-suck-back ability of five new high-speed air turbine handpiece models was evaluated in this study. First, suck-back pressure with water displacement within a glass tube was measured. Next, under three different conditions, how many on-off times it takes before fluorescent stains became visible on a piece of gauze at the exhaust vent was counted and the presence of fluorescent stains on the exhaust vents itself was examined. As a result, the water height for each part of one handpiece, the TWINPOWER TURBINE PAR-4HX-O, was below 0 mm. Except for under full emersion, this model, the TWINPOWER TURBINE PAR-4HX-O, did not have any visible fluorescence penetration to the exhaust vent even after 500 on-off switches under fume/mist conditions. Conversely, the other handpieces (Ti-Max X700L, T1 CONTROL, SYNEA TA-98CLED, GENTLE silence LUX 8000B) showed suck-back. In conclusion, the first mentioned new turbine handpiece, the TWINPOWER TURBINE PAR-4HX-O, had a possibility of no suck-back by itself. However, full immersion of the whole head of the handpiece which is not completely sealed must be avoided to prevent liquid intake.

  3. High and low schizotypal female subjects do not differ in spatial memory abilities in a virtual reality task.

    Science.gov (United States)

    García-Montes, José Manuel; Noguera, Carmen; Alvarez, Dolores; Ruiz, Marina; Cimadevilla Redondo, José Manuel

    2014-01-01

    Schizotypy is a psychological construct related to schizophrenia. The exact relationship between both entities is not clear. In recent years, schizophrenia has been associated with hippocampal abnormalities and spatial memory problems. The aim of this study was to determine possible links between high schizotypy (HS) and low schizotypy (LS) and spatial abilities, using virtual reality tasks. We hypothesised that the HS group would exhibit a lower performance in spatial memory tasks than the LS group. Two groups of female students were formed according to their score on the ESQUIZO-Q-A questionnaire. HS and LS subjects were tested on two different tasks: the Boxes Room task, a spatial memory task sensitive to hippocampal alterations and a spatial recognition task. Data showed that both groups mastered both tasks. Groups differed in personality features but not in spatial performance. These results provide valuable information about the schizotypy-schizophrenia connections. Schizotypal subjects are not impaired on spatial cognition and, accordingly, the schizotypy-schizophrenia relationship is not straightforward.

  4. Explaining the T,V-dependent dynamics of glass forming liquids: The cooperative free volume model tested against new simulation results.

    Science.gov (United States)

    White, Ronald P; Lipson, Jane E G

    2017-11-14

    In this article, we derive a rate model, the "cooperative free volume" (CFV) model, to explain relaxation dynamics in terms of a system's free volume, Vfree, and its temperature, T, over widely varied pressure dependent conditions. In the CFV model, the rate a molecule moves a distance on the order of its own size is dependent on the cooperation of surrounding molecules to open up enough free space. To test CFV, we have generated extensive T,V dependent simulation data for structural relaxation times, τ, on a Kob and Andersen type Lennard-Jones (KA-LJ) fluid. The Vfree = V - Vhc values are obtained by estimating the limiting hard core volume, Vhc, through analysis of the KA-LJ PVT data. We provide the first simulation evidence that shows ln τ to be linearly proportional to 1/Vfree on isotherms, with T-dependent slopes, thus confirming our recent analysis of experimental systems. The linear relationship exhibited by the simulation data is further shown to occur at temperatures both above and below the transition to Arrhenius behavior. We also show that the gas kinetic T-dependent contribution is important in simulation results and that there can be a significant entropic contribution from lingering molecular hard-cores at high T. A key result is that non-Arrhenius relaxation behavior is always exhibited on isobars of the KA-LJ fluid, even at high T. The CFV model predicts all of this behavior over a surprisingly wide range of the KA-LJ T,V space, fitting it with just a single set of three parameters. The CFV approach leads to a framework wherein the number of cooperating particles, and thus, the process free energy of activation, is inversely proportional to Vfree, and this is the foundation for the form of the model's volume contribution, a form that we find to hold for all systems and at all temperatures.

  5. Increased Internet use and poorer ability to manage emotions in youth at high-risk for psychosis

    Directory of Open Access Journals (Sweden)

    Andrea Pelletier-Baldelli

    2015-12-01

    Full Text Available The relationship between Internet use and social behavior remains unknown. However, research indicates that Internet use (IU may have some causal role in certain types of psychopathology and overall functioning. In contrast, other work suggests that IU may be protective and buffer against social isolation. Poorer emotional processing (EP is characteristic of schizophrenia, and these deficits are present prior to illness onset (the ultra high-risk period (UHR. UHR adolescents/young adults also fall within an age demographic characterized by extensive IU, which suggests that evaluating a link between IU and social behavior in this population may be especially informative. The present study examined the relationship between IU and emotional processing in 98 adolescents/young adults (52 UHR youth and 46 controls. UHR youth exhibited greater problematic IU (β = −6.49, F(1,95 = 8.79, p = 0.002 and social withdrawal/problems resulting from this use (β = −3.23, F(1,95 = 11.43, p < 0.001, as well deficits in emotional processing in comparison to healthy peers (β = 4.59, F(1,94 = 5.52, p = 0.011. Furthermore, the social problems resulting from IU were significantly related to the ability to process emotional information in the UHR group (β = −0.51, t(1,48 = −2.10, p = 0.021. UHR youth showed evidence of problematic IU relative to controls, and the social problems resulting from IU related to poorer EP. Findings replicate extant research involving other psychosis risk populations, while adding information regarding how social processes may relate to IU.

  6. Application of wastewater with high organic load for saline-sodic soil reclamation focusing on soil purification ability

    Directory of Open Access Journals (Sweden)

    M.A. Kameli

    2017-04-01

    Full Text Available Fresh water source scarcity in arid and semiarid area is limitation factor for saline-sodic soil reclamation. The reusing of agricultural drainage and industrial wastewater are preferred strategies for combating with this concern. The objective of current study was evaluation in application of industrial sugar manufacture wastewater due to high soluble organic compounds in saline-sodic and sodic soil. Also soil ability in wastewater organic compounds removal was second aim of present study. Saline-sodic and sodic soil sample was leached in soil column by diluted wastewater of amirkabir sugar manufacture in Khuzestan Province of Iran at constant water head. Sodium, electric conductivity and chemical oxygen demand of soil column leachate were measured per each pore volume. The experimental kinetics of wastewater organic compounds on two saline-sodic and sodic soil were also investigated by three pseudo second order, intra particle diffusion and elovich model. The results of current study showed that electric conductivity of saline-sodic soil was decreased to 90% during 3 initial pore volumes, from other side exchangeable sodium percent of saline-sodic and sodic soil decreased 30 and 71 percent, respectively. There were no significant different between wastewater chemical oxygen demand removal by saline-sodic and sodic soil in both batch and column studies. Wastewater chemical oxygen demand was decreased to 35% during pass through soil column. The results showed that the adsorption kinetics of wastewater organic compounds were best fitted by the pseudo-second order model with 99 percent correlation coefficient (r2=0.99%.

  7. Relationships between Students' Self-Educational Ability in Their College Age and Personal Teaching Theory (PTT) in their High School Age

    OpenAIRE

    森, 敏昭; 清水, 益治; 石田, 潤; 冨永, 美穂子

    2003-01-01

    This study investigated the relationships of students' self-educational ability in their college age with their personal teaching theory (PTT) in their high school age. A total of 789 students completed two kinds of questionaires, one of which was to measure their selfeducational ability (interest in learning subjects, self-directed thinking, skillfulness of learning method, self-monitoring, planning, independence, and self-actualization) in their college age and the other was to measure thei...

  8. Academic scientific-production in Brazil in the area of high abilities/giftedness on the period from 1987 to 2011

    Directory of Open Access Journals (Sweden)

    Miguel Claudio Moriel Chacon

    2014-06-01

    Full Text Available Among students with special educational needs, subjects of special education, are those with high ability/giftedness, a complex phenomenon that requires the participation of education professionals and researchers to foster the potential of development of these students. In this sense, we aimed to identify and analyze thesis and dissertations that they propose to investigate the theme high ability/giftedness, verifying participation of the area of education in these studies. The study was done through a literature review, guided by the following questions: Have the researches on high ability/giftedness been growing in recent years? What is the participation of education area in those researches? What are the issues related to high ability/giftedness addressed in Education? The results show that the institutions present an increasing trend and there is a predominance of education area in this scientific production. However, there is an imbalance between the institutions that aim to investigate the theme in Brazilian regions, as well as among the cases covered by these researches on high ability/giftedness.

  9. The Effects of High Scientific Literacy, Self-Efficacy, and Achievement Motivation on Teachers' Ability to Compose Effective Tests: Case Study from Manado, Indonesia

    Science.gov (United States)

    Poluakan, Cosmas

    2012-01-01

    This research was conducted to determine the effects of high scientific literacy, self-efficacy, and achievement motivation on teachers' ability to compose effective tests. It was conducted among junior high school science teachers in Manado, North Sulawesi Province, Indonesia, from April to September 2011, using a cross-sectional survey design.…

  10. Crystallization dynamics in glass-forming systems

    Energy Technology Data Exchange (ETDEWEB)

    Cullinan, Timothy Edward [Iowa State Univ., Ames, IA (United States)

    2016-02-19

    Crystallization under far-from-equilibrium conditions is investigated for two different scenarios: crystallization of the metallic glass alloy Cu50Zr50 and solidification of a transparent organic compound, o-terphenyl. For Cu50Zr50, crystallization kinetics are quanti ed through a new procedure that directly fits thermal analysis data to the commonly utilized JMAK model. The phase evolution during crystallization is quantified through in-situ measurements (HEXRD, DSC) and ex-situ microstructural analysis (TEM, HRTEM). The influence of chemical partitioning, diffusion, and crystallographic orientation on this sequence are examined. For o-terphenyl, the relationship between crystal growth velocity and interface undercooling is systematically studied via directional solidification.

  11. Design and Development Computer-Based E-Learning Teaching Material for Improving Mathematical Understanding Ability and Spatial Sense of Junior High School Students

    Science.gov (United States)

    Nurjanah; Dahlan, J. A.; Wibisono, Y.

    2017-02-01

    This paper aims to make a design and development computer-based e-learning teaching material for improving mathematical understanding ability and spatial sense of junior high school students. Furthermore, the particular aims are (1) getting teaching material design, evaluation model, and intrument to measure mathematical understanding ability and spatial sense of junior high school students; (2) conducting trials computer-based e-learning teaching material model, asessment, and instrument to develop mathematical understanding ability and spatial sense of junior high school students; (3) completing teaching material models of computer-based e-learning, assessment, and develop mathematical understanding ability and spatial sense of junior high school students; (4) resulting research product is teaching materials of computer-based e-learning. Furthermore, the product is an interactive learning disc. The research method is used of this study is developmental research which is conducted by thought experiment and instruction experiment. The result showed that teaching materials could be used very well. This is based on the validation of computer-based e-learning teaching materials, which is validated by 5 multimedia experts. The judgement result of face and content validity of 5 validator shows that the same judgement result to the face and content validity of each item test of mathematical understanding ability and spatial sense. The reliability test of mathematical understanding ability and spatial sense are 0,929 and 0,939. This reliability test is very high. While the validity of both tests have a high and very high criteria.

  12. Self-Perceptions of Ability and Achievement across the High School Transition: Investigation of a State-Trait Model

    Science.gov (United States)

    Silverthorn, Naida; DuBois, David L.; Crombie, Gail

    2005-01-01

    The authors investigated the relationship between self-perceptions of ability and achievement in math, science, and English from Grades 8 to 11 (N = 342). A state-trait model that included an association between stable (i.e., trait-like) components of self-perceptions and achievement as well as time-specific (i.e., state-like) effects during the…

  13. The Relationship between Self-Esteem and Academic Achievement in High Ability Students: Evidence from the Wollongong Youth Study

    Science.gov (United States)

    Vialle, Wilma; Heaven, Patrick C. L.; Ciarrochi, Joseph

    2015-01-01

    The relationship between self-esteem and academic achievement is one that is regarded by many educators as a well-established fact. This belief has been often invoked in order to argue against the provision of ability grouping for gifted students. Refuting that commonly-held belief, this research examined the relationship between self-esteem and…

  14. The Influence of Self-Efficacy Beliefs and Metacognitive Prompting on Genetics Problem Solving Ability among High School Students in Kenya

    Science.gov (United States)

    Aurah, Catherine Muhonja

    Within the framework of social cognitive theory, the influence of self-efficacy beliefs and metacognitive prompting on genetics problem solving ability among high school students in Kenya was examined through a mixed methods research design. A quasi-experimental study, supplemented by focus group interviews, was conducted to investigate both the outcomes and the processes of students' genetics problem-solving ability. Focus group interviews substantiated and supported findings from the quantitative instruments. The study was conducted in 17 high schools in Western Province, Kenya. A total of 2,138 high school students were purposively sampled. A sub-sample of 48 students participated in focus group interviews to understand their perspectives and experiences during the study so as to corroborate the quantitative data. Quantitative data were analyzed through descriptive statistics, zero-order correlations, 2 x 2 factorial ANOVA,, and sequential hierarchical multiple regressions. Qualitative data were transcribed, coded, and reported thematically. Results revealed metacognitive prompts had significant positive effects on student problem-solving ability independent of gender. Self-efficacy and metacognitive prompting significantly predicted genetics problem-solving ability. Gender differences were revealed, with girls outperforming boys on the genetics problem-solving test. Furthermore, self-efficacy moderated the relationship between metacognitive prompting and genetics problem-solving ability. This study established a foundation for instructional methods for biology teachers and recommendations are made for implementing metacognitive prompting in a problem-based learning environment in high schools and science teacher education programs in Kenya.

  15. The implementation of multiple intelligences based teaching model to improve mathematical problem solving ability for student of junior high school

    Science.gov (United States)

    Fasni, Nurli; Fatimah, Siti; Yulanda, Syerli

    2017-05-01

    This research aims to achieve some purposes such as: to know whether mathematical problem solving ability of students who have learned mathematics using Multiple Intelligences based teaching model is higher than the student who have learned mathematics using cooperative learning; to know the improvement of the mathematical problem solving ability of the student who have learned mathematics using Multiple Intelligences based teaching model., to know the improvement of the mathematical problem solving ability of the student who have learned mathematics using cooperative learning; to know the attitude of the students to Multiple Intelligences based teaching model. The method employed here is quasi-experiment which is controlled by pre-test and post-test. The population of this research is all of VII grade in SMP Negeri 14 Bandung even-term 2013/2014, later on two classes of it were taken for the samples of this research. A class was taught using Multiple Intelligences based teaching model and the other one was taught using cooperative learning. The data of this research were gotten from the test in mathematical problem solving, scale questionnaire of the student attitudes, and observation. The results show the mathematical problem solving of the students who have learned mathematics using Multiple Intelligences based teaching model learning is higher than the student who have learned mathematics using cooperative learning, the mathematical problem solving ability of the student who have learned mathematics using cooperative learning and Multiple Intelligences based teaching model are in intermediate level, and the students showed the positive attitude in learning mathematics using Multiple Intelligences based teaching model. As for the recommendation for next author, Multiple Intelligences based teaching model can be tested on other subject and other ability.

  16. The effectiveness of web-programming module based on scientific approach to train logical thinking ability for students in vocational high school

    Science.gov (United States)

    Nashiroh, Putri Khoirin; Kamdi, Waras; Elmunsyah, Hakkun

    2017-09-01

    Web programming is a basic subject in Computer and Informatics Engineering, a program study in a vocational high school. It requires logical thinking ability in its learning activities. The purposes of this research were (1) to develop a web programming module that implement scientific approach that can improve logical thinking ability for students in vocational high school; and (2) to test the effectiveness of web programming module based on scientific approach to train students' logical thinking ability. The results of this research was a web-programming module that apply scientific approach for learning activities to improve logical thinking ability of students in the vocational high school. The results of the effectiveness test of web-programming module give conclusion that it was very effective to train logical thinking ability and to improve learning result, this conclusion was supported by: (1) the average of posttest result of students exceeds the minimum criterion value, it was 79.91; (2) the average percentage of students' logical thinking score is 82,98; and (3) the average percentage of students' responses to the web programming module was 81.86%.

  17. Syntactic and Story Structure Complexity in the Narratives of High- and Low-Language Ability Children with Autism Spectrum Disorder

    OpenAIRE

    Eleni Peristeri; Maria Andreou; Ianthi M. Tsimpli

    2017-01-01

    Although language impairment is commonly associated with the autism spectrum disorder (ASD), the Diagnostic Statistical Manual no longer includes language impairment as a necessary component of an ASD diagnosis (American Psychiatric Association, 2013). However, children with ASD and no comorbid intellectual disability struggle with some aspects of language whose precise nature is still outstanding. Narratives have been extensively used as a tool to examine lexical and syntactic abilities, as ...

  18. Girls underestimate maths ability

    Science.gov (United States)

    2017-05-01

    A study by psychologists in the US has found that high-school girls rate their competence in mathematics lower than boys, even for those with similar abilities (Front. Psychol. 10.3389/fpsyg.2017.00386).

  19. Self-Efficacy, Test Anxiety, and Self-Reported Test-Taking Ability: How Do They Differ between High- and Low-Achieving Students?

    Science.gov (United States)

    Vuk, Jasna; Morse, David T.

    2013-01-01

    The purpose of this study was to compare high- and low-achieving undergraduate college students on selfefficacy, test anxiety, and self-reported test-taking ability. Eighty students from 2 sections of educational psychology course participated in the study; complete data were collected for 76 students. Before taking their first exam, students…

  20. Brief Report: IQ Split Predicts Social Symptoms and Communication Abilities in High-Functioning Children with Autism Spectrum Disorders

    Science.gov (United States)

    Black, David O.; Wallace, Gregory L.; Sokoloff, Jennifer L.; Kenworthy, Lauren

    2009-01-01

    We investigated the relationship of discrepancies between VIQ and NVIQ (IQ split) to autism symptoms and adaptive behavior in a sample of high-functioning (mean FSIQ = 98.5) school-age children with autism spectrum disorders divided into three groups: discrepantly high VIQ (n = 18); discrepantly high NVIQ (n = 24); and equivalent VIQ and NVIQ (n =…

  1. On the Ability of Ascends to Constrain Fossil Fuel, Ocean and High Latitude Emissions: Flux Estimation Experiments

    Science.gov (United States)

    Crowell, S.; Kawa, S. R.; Hammerling, D.; Moore, B., III; Rayner, P. J.

    2014-12-01

    In Hammerling et al., 2014 (H14) the authors demonstrated a geostatistical method for mapping satellite estimates of column integrated CO2 mixing ratio, denoted XCO2, that incorporates the spatial variability in satellite-measured XCO2 as well as measurement precision. The goal of the study was to determine whether the Active Sensing of CO2 over Nights, Days and Seasons (ASCENDS) mission would be able to detect changes in XCO2 given changes in the underlying fluxes for different levels of instrument precision. Three scenarios were proposed: a flux-neutral shift in fossil fuel emissions from Europe to China (shown in the figure); a permafrost melting event; interannual variability in the Southern Oceans. The conclusions of H14 were modest but favorable for detectability in each case by ASCENDS given enough observations and sufficient precision. These signal detection experiments suggest that ASCENDS observations, together with a chemical transport model and data assimilation methodology, would be sufficient to provide quality estimates of the underlying surface fluxes, so long as the ASCENDS observations are precise enough. In this work, we present results that bridge the gap between the previous signal detection work by [Hammerling et al., 2014] and the ability of transport models to recover flux perturbations from ASCENDS observations utilizing the TM5-4DVAR data assimilation system. In particular, we will explore the space of model and observational uncertainties that will yield useful scientific information in each of the flux perturbation scenarios. This work will give a sense of the ability of ASCENDS to answer key questions about some of the foremost questions in carbon cycle science today. References: Hammerling, D., Kawa, S., Schaefer, K., and Michalak, A. (2014). Detectability of CO2 flux signals by a space-based lidar mission. Submitted.

  2. Effects of brief mindful breathing and loving-kindness meditation on shame and social problem solving abilities among individuals with high borderline personality traits.

    Science.gov (United States)

    Keng, Shian-Ling; Tan, Jun Xian

    2017-10-01

    Borderline personality disorder (BPD) is a severe mental condition characterized by a range of cognitive and behavioral vulnerabilities, including chronic shame and deficits in social problem solving (SPS) abilities. Little research however, has examined strategies that may alleviate shame and SPS deficits among individuals with BPD traits. Using a laboratory experimental approach, the present study compared the effects of a brief mindfulness versus loving-kindness meditation (LKM) induction on shame and SPS abilities in a sample of adults with high BPD traits. Eighty-eight participants underwent a shame induction procedure involving recall of a negative autobiographical memory. They were then randomly assigned to 10 min of mindful breathing or LKM, or a no-instruction condition. Shame and SPS abilities were assessed via visual analogue scales and the Means-Ends Problem Solving task respectively. Results indicated that there were significant decreases in shame from pre-to post-regulation in the mindfulness group versus the LKM and no-instruction groups. Groups did not differ on changes in SPS abilities from pre-to post-regulation. Overall, the findings support the efficacy of mindfulness as a strategy to regulate shame among individuals with BPD traits, and raises questions with regard to the utility of LKM in modulating shame in the context of high emotional arousal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Relating the ability of mallards to ingest high levels of sediment to potential contaminant exposure in waterfowl

    Science.gov (United States)

    Heinz, Gary H.; Beyer, W. Nelson; Hoffman, David J.; Audet, Daniel J.

    2010-01-01

    When waterfowl feed from the bottom of bodies of water, they sometimes ingest sediments along with their food, and this sediment can be a major source of contaminants. Learning how much sediment waterfowl can consume in their diet and still maintain their health would be helpful in assessing potential threats from contaminants in sediment. In a controlled laboratory study the maximum tolerated percentage of sediment in the diet of mallards (Anas platyrhynchos) was measured. When fed a well-balanced commercial avian diet, 50, 60, or 70% sediment in the diet on a dry-weight basis did not cause weight loss over a two-week period. Ducks fed this same commercial diet, but containing 80 or 90% sediment, lost 8.6 and 15.6% of their body weight, respectively, in the first week on those diets. After factoring in the ability of the mallards to sieve out some of the sediment from their diet before swallowing it, we concluded that the mallards could maintain their health even when approximately half of what they swallowed, on a dry-weight basis, was sediment.

  4. White-rot fungus Ganoderma sp.En3 had a strong ability to decolorize and tolerate the anthraquinone, indigo and triphenylmethane dye with high concentrations.

    Science.gov (United States)

    Lu, Ruoying; Ma, Li; He, Feng; Yu, Dong; Fan, Ruozhi; Zhang, Yangming; Long, Zheping; Zhang, Xiaoyu; Yang, Yang

    2016-03-01

    The ability of the white-rot fungus Ganoderma sp.En3 to decolorize different kinds of dyes widely applied in the textile and dyeing industry, including the anthraquinone dye Remazol Brilliant Blue R (RBBR), indigo dye indigo carmine and triphenylmethane dye methyl green, was evaluated in this study. Ganoderma sp.En3 had a strong capability of decolorizing high concentrations of RBBR, indigo carmine and methyl green. Obvious reduction of Chemical Oxygen Demand was observed after decolorization of different dyes. Ganoderma sp.En3 had a strong ability to tolerate RBBR, indigo carmine and methyl green with high concentrations. High concentrations of RBBR, indigo carmine and methyl green could also be efficiently decolorized by the crude enzyme of Ganoderma sp.En3. Different redox mediators such as syringaldehyde, acetosyringone and acetovanillone could enhance the decolorization capability for higher concentration of indigo carmine and methyl green. Different metal ions had little effect on the ability of the crude enzyme to decolorize indigo carmine and methyl green. Our study suggested that Ganoderma sp.En3 had a strong capability for decolorizing and tolerating high concentrations of different types of dyes such as RBBR, indigo carmine and methyl green.

  5. Measuring Creative Imagery Abilities

    Directory of Open Access Journals (Sweden)

    Dorota M. Jankowska

    2015-10-01

    Full Text Available Over the decades, creativity and imagination research developed in parallel, but they surprisingly rarely intersected. This paper introduces a new theoretical model of creative imagination, which bridges creativity and imagination research, as well as presents a new psychometric instrument, called the Test of Creative Imagery Abilities (TCIA, developed to measure creative imagery abilities understood in accordance with this model. Creative imagination is understood as constituted by three interrelated components: vividness (the ability to create images characterized by a high level of complexity and detail, originality (the ability to produce unique imagery, and transformativeness (the ability to control imagery. TCIA enables valid and reliable measurement of these three groups of abilities, yielding the general score of imagery abilities and at the same time making profile analysis possible. We present the results of eight studies on a total sample of more than 1,700 participants, showing the factor structure of TCIA using confirmatory factor analysis, as well as provide data confirming this instrument’s validity and reliability. The availability of TCIA for interested researchers may result in new insights and possibilities of integrating the fields of creativity and imagination science.

  6. Measuring creative imagery abilities

    Science.gov (United States)

    Jankowska, Dorota M.; Karwowski, Maciej

    2015-01-01

    Over the decades, creativity and imagination research developed in parallel, but they surprisingly rarely intersected. This paper introduces a new theoretical model of creative visual imagination, which bridges creativity and imagination research, as well as presents a new psychometric instrument, called the Test of Creative Imagery Abilities (TCIA), developed to measure creative imagery abilities understood in accordance with this model. Creative imagination is understood as constituted by three interrelated components: vividness (the ability to create images characterized by a high level of complexity and detail), originality (the ability to produce unique imagery), and transformativeness (the ability to control imagery). TCIA enables valid and reliable measurement of these three groups of abilities, yielding the general score of imagery abilities and at the same time making profile analysis possible. We present the results of nine studies on a total sample of more than 1700 participants, showing the factor structure of TCIA using confirmatory factor analysis, as well as provide data confirming this instrument's validity and reliability. The availability of TCIA for interested researchers may result in new insights and possibilities of integrating the fields of creativity and imagination science. PMID:26539140

  7. Ability of Stress, Sense of Control, and Self-Theories to Predict Swedish High School Students' Final Grades

    Science.gov (United States)

    Ollfors, Marianne; Andersson, Sven Ingmar

    2007-01-01

    The aim of this study was to investigate self-theories (theories of intelligence, confidence in one's intelligence, internal attribution of failure, academic self-efficacy), specific control, and experiencing of stress by means of a questionnaire for 915 Swedish high school students. Factor analysis yielded 6 stress domains (Workload, Psychosocial…

  8. Does magnesium compromise the high temperature process ability of novel biodegradable and bioresorbables PLLA/Mg composites?

    Energy Technology Data Exchange (ETDEWEB)

    Cifuentes, S. C.; Benavemente, R.; Gonzalez-Carrasco, J. L.

    2014-10-01

    This paper addresses the influence of magnesium on melting behaviour and thermal stability of novel bioresorbable PLLA/Mg composites as a way to investigate their processability by conventional techniques, which likely will require a melt process at high temperature to mould the material by using a compression, extrusion or injection stage. For this purpose, and to avoid any high temperature step before analysis, films of PLLA loaded with magnesium particles of different sizes and volume fraction were prepared by solvent casting. DSC, modulated DSC and thermogravimetry analysis demonstrate that although thermal stability of PLLA is reduced, the temperature window for processing the PLLA/Mg composites by conventional thermoplastic routes is wide enough. Moreover, magnesium particles do not alter the crystallization behaviour of the polymer from the melt, which allows further annealing treatments to optimize the crystallinity in terms of the required combination of mechanical properties and degradation rate. (Author)

  9. The plateau zokors' learning and memory ability is related to the high expression levels of foxP2 in the brain.

    Science.gov (United States)

    Ma, Ben-Yuan; Wei, Lian; Sun, Sheng-Zhen; Wang, Duo-Wei; Wei, Deng-Bang

    2014-04-25

    Plateau zokor (Myospalax baileyi) is a subterranean mammal. Plateau zokor has high learning and memory ability, and can determine the location of blocking obstacles in their tunnels. Forkhead box p2 (FOXP2) is a transcription factor implicated in the neural control of orofacial coordination and sensory-motor integration, particularly with respect to learning, memory and vocalization. To explore the association of foxP2 with the high learning and memory ability of plateau zokor, the cDNA of foxP2 of plateau zokor was sequenced; by using plateau pika as control, the expression levels of foxP2 mRNA and FOXP2 protein in brain of plateau zokor were determined by real-time PCR and Western blot, respectively; and the location of FOXP2 protein in the brain of plateau zokor was determined by immunohistochemistry. The result showed that the cDNA sequence of plateau zokor foxP2 was similar to that of other mammals and the amino acid sequences showed a relatively high degree of conservation, with the exception of two particular amino acid substitutions [a Gln (Q)-to-His (H) change at position 231 and a Ser (S)-to-Ile (I) change at position 235]. Higher expression levels of foxP2 mRNA (3-fold higher) and FOXP2 protein (>2-fold higher) were detected in plateau zokor brain relative to plateau pika brain. In plateau zokor brain, FOXP2 protein was highly expressed in the cerebral cortex, thalamus and the striatum (a basal ganglia brain region). The results suggest that the high learning and memory ability of plateau zokor is related to the high expression levels of foxP2 in the brain.

  10. Cancer-Associated Fibroblasts from lung tumors maintain their immuno-suppressive abilities after high-dose irradiation

    Directory of Open Access Journals (Sweden)

    Laia eGorchs

    2015-05-01

    Full Text Available Accumulating evidence supports the notion that high-dose (>5 Gy radiotherapy (RT regimens are triggering stronger pro-immunogenic effects than standard low-dose (2 Gy regimens. However, the effects of RT on certain immunoregulatory elements in tumors remain unexplored. In this study we have investigated the effects of high-dose irradiation (HD-RT on the immunomodulating functions of cancer-associated fibroblasts (CAFs. Primary CAF cultures were established from lung cancer specimens derived from patients diagnosed for non-small cell lung cancer. Irradiated and non-irradiated CAFs were examined for immunomodulation in experiments with peripheral blood mononuclear cells from random, healthy donors. Regulation of lymphocytes behavior was checked by lymphocyte proliferation assays, lymphocyte migration assays and T-cell cytokine production. Additionally, CAF-secreted immuno-regulatory factors were studied by multiplex protein arrays, ELISAs and by LC-MS/MS proteomics. In all functional assays we observed a powerful immuno-suppressive effect exerted by CAF-conditioned medium on activated T-cells (p>0,001, and this effect was sustained after a single radiation dose of 18 Gy. Relevant immuno-suppressive molecules such as prostaglandin E2, interleukin-6 and -10, or transforming growth factor-β were found in CAF conditioned medium, but their secretion was unchanged after irradiation. Finally, immunogenic cell death responses in CAFs were studied by exploring the release of high motility group box-1 and ATP. Both alarmins remained undetectable before and after irradiation. In conclusion, CAFs play a powerful immuno-suppressive effect over activated T-cells, and this effect remains unchanged after HD-RT. Importantly, CAFs do not switch on immunogenic cell death responses after exposure to HD-RT.

  11. Mechanical ball-milling preparation of fullerene/cobalt core/shell nanocomposites with high electrochemical hydrogen storage ability.

    Science.gov (United States)

    Bao, Di; Gao, Peng; Shen, Xiande; Chang, Cheng; Wang, Longqiang; Wang, Ying; Chen, Yujin; Zhou, Xiaoming; Sun, Shuchao; Li, Guobao; Yang, Piaoping

    2014-02-26

    The design and synthesis of new hydrogen storage nanomaterials with high capacity at low cost is extremely desirable but remains challenging for today's development of hydrogen economy. Because of the special honeycomb structures and excellent physical and chemical characters, fullerenes have been extensively considered as ideal materials for hydrogen storage materials. To take the most advantage of its distinctive symmetrical carbon cage structure, we have uniformly coated C60's surface with metal cobalt in nanoscale to form a core/shell structure through a simple ball-milling process in this work. The X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, high-solution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrometry (EDX) elemental mappings, and X-ray photoelectron spectroscopy (XPS) measurements have been conducted to evaluate the size and the composition of the composites. In addition, the blue shift of C60 pentagonal pinch mode demonstrates the formation of Co-C chemical bond, and which enhances the stability of the as-obtained nanocomposites. And their electrochemical experimental results demonstrate that the as-obtained C60/Co composites have excellent electrochemical hydrogen storage cycle reversibility and considerably high hydrogen storage capacities of 907 mAh/g (3.32 wt % hydrogen) under room temperature and ambient pressure, which is very close to the theoretical hydrogen storage capacities of individual metal Co (3.33 wt % hydrogen). Furthermore, their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible C60/Co↔C60/Co-Hx reaction is the dominant cycle process.

  12. Formation of the Ability to Identify the Causes of Deviant Behavior among Adolescents in Students of Pedagogical High School

    Directory of Open Access Journals (Sweden)

    Busarova O.R.,

    2014-11-01

    Full Text Available The aim of the presented research was the development and testing of special exercises for the formation of skills to competently determine the causes of deviant behavior among adolescents during psychology classes in students of pedagogical high school. The study involved 23 students of 2nd grade at Moscow State Pedagogical University. Methodological basis for students training were the results of studies carried out in line with the concept of psychological diagnosis by A.F. Anufriev. The focus of the proposed exercises is the diagnostic hypotheses production, because in previous studies it was noted that this step of the diagnostic search is of the greatest difficulty for teachers. The efficiency of the developed exercises was evaluated by the quality of the problems solution proposed by the students to assess the causes of deviant behavior of middle school students. According to the study, we concluded that the exercises proposed to pedagogical high school students increase quality of solving problems and can significantly reduce the number of errors inherent in the activities of teachers to determine the causes of the behavior of students.

  13. CONNECTION BETWEEN SOME MOTORIC ABILITIES WITH SUCCESS IN REALIZATION OF PROGRAMMED CONTENTS FROM THE AREA OF GYMNASTICS OF THE FOURTH GRADE OF HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    Jovica Petković

    2007-05-01

    Full Text Available This research is undertaken for the purpose of defi ning and determinating of the le vel of connection between some motoric abilities with effi ciency in realization of some pro gramme issnes in the area of gymnastic (stretched – legged jump and folded – legged jump. On the sample of fi fty students from the fourth grade of High school, examined stu dents have been tested on ten motoric tests and on two specifi c motoric assignmentsstre tched – legged jump and folded – legged jump. The results of this research clearly point that there exist the multitude of statistically important coeffi cients of correlation between treated motoric abilities and applied assignments

  14. Tracing genomic variations in two highly virulent Yersinia enterocolitica strains with unequal ability to compete for host colonization

    Directory of Open Access Journals (Sweden)

    Garzetti Debora

    2012-09-01

    Full Text Available Abstract Background Yersinia enterocolitica is a gastrointestinal foodborne pathogen found worldwide and which especially affects infants and young children. While different bioserotypes have been associated with varying pathogenicity, research on Y. enterocolitica is mainly conducted on the highly virulent mouse-lethal strains of biotype 1B and serotype O:8. We demonstrate here that two Y. enterocolitica bioserotype 1B/O:8 strains, 8081 and WA-314, display different virulence and fitness properties in a mouse model. In vivo co-infection experiments revealed that strain WA-314 overcomes strain 8081 in the colonization of spleen and liver. To trace the reasons of this incongruity, we present here the first high-quality sequence of the whole genome of strain WA-314 and compare it to the published genome of strain 8081. Results Regions previously accepted as unique to strain 8081, like the YAPI and YGI-3 genomic islands, are absent from strain WA-314, confirming their strain-specificity. On the other hand, some fitness- and bacterial competition-associated features, such as a putative colicin cluster and a xenobiotic-acyltransferase-encoding gene, are unique to strain WA-314. Additional acquisitions of strain WA-314 are seven prophage-like regions. One of these prophages, the 28-kb P4-like prophage YWA-4, encodes a PilV-like protein that may be used for adhesion to and invasion of the intestinal cells. Furthermore, a putative autotransporter and two type 1 fimbrial proteins of strain WA-314 show a sequence similarity Y. enterocolitica strains 8081 and WA-314 and thus the different efficiency of host colonization. Further important differences were found in two pYV plasmid-encoded virulence factors, YopM and YscP. The impact of these differences on virulence is discussed. Conclusions Our study emphasizes that the virulence of pathogens can be increased, by acquiring new genes and/or improving the function of essential virulence proteins, resulting

  15. Tracing genomic variations in two highly virulent Yersinia enterocolitica strains with unequal ability to compete for host colonization

    Science.gov (United States)

    2012-01-01

    Background Yersinia enterocolitica is a gastrointestinal foodborne pathogen found worldwide and which especially affects infants and young children. While different bioserotypes have been associated with varying pathogenicity, research on Y. enterocolitica is mainly conducted on the highly virulent mouse-lethal strains of biotype 1B and serotype O:8. We demonstrate here that two Y. enterocolitica bioserotype 1B/O:8 strains, 8081 and WA-314, display different virulence and fitness properties in a mouse model. In vivo co-infection experiments revealed that strain WA-314 overcomes strain 8081 in the colonization of spleen and liver. To trace the reasons of this incongruity, we present here the first high-quality sequence of the whole genome of strain WA-314 and compare it to the published genome of strain 8081. Results Regions previously accepted as unique to strain 8081, like the YAPI and YGI-3 genomic islands, are absent from strain WA-314, confirming their strain-specificity. On the other hand, some fitness- and bacterial competition-associated features, such as a putative colicin cluster and a xenobiotic-acyltransferase-encoding gene, are unique to strain WA-314. Additional acquisitions of strain WA-314 are seven prophage-like regions. One of these prophages, the 28-kb P4-like prophage YWA-4, encodes a PilV-like protein that may be used for adhesion to and invasion of the intestinal cells. Furthermore, a putative autotransporter and two type 1 fimbrial proteins of strain WA-314 show a sequence similarity enterocolitica strains 8081 and WA-314 and thus the different efficiency of host colonization. Further important differences were found in two pYV plasmid-encoded virulence factors, YopM and YscP. The impact of these differences on virulence is discussed. Conclusions Our study emphasizes that the virulence of pathogens can be increased, by acquiring new genes and/or improving the function of essential virulence proteins, resulting in permanently hyper

  16. Use of prosody and information structure in high functioning adults with Autism in relation to language ability

    Directory of Open Access Journals (Sweden)

    Anne-Marie R DePape

    2012-03-01

    Full Text Available Abnormal prosody is a striking feature of the speech of those with Autism Spectrum Disorder (ASD, but previous reports suggest large variability among those with ASD. Here we show that part of this heterogeneity can be explained by level of language functioning. We recorded semi-spontaneous but controlled conversations in adults with and without Autism Spectrum Disorder and measured features related to pitch and duration to determine (1 general use of prosodic features, (2 prosodic use in relation to marking information structure, specifically, the emphasis of new information in a sentence (focus as opposed to information already given in the conversational context (topic, and (3 the relation between prosodic use and level of language function. We found that, compared to typical adults, those with ASD with high language functioning generally used a larger pitch range than controls but did not mark information structure, whereas those with moderate language functioning generally used a smaller pitch range than controls but marked information structure appropriately to a large extent. Both impaired general prosodic use and impaired marking of information structure would be expected to seriously impact social communication and thereby lead to increased difficulty in personal domains, such as making and keeping friendships, and in professional domains, such as competing for employment opportunities.

  17. Vertebrate dissimilarity due to turnover and richness differences in a highly beta-diverse region: the role of spatial grain size, dispersal ability and distance.

    Directory of Open Access Journals (Sweden)

    Jaime M Calderón-Patrón

    Full Text Available We explore the influence of spatial grain size, dispersal ability, and geographic distance on the patterns of species dissimilarity of terrestrial vertebrates, separating the dissimilarity explained by species replacement (turnover from that resulting from richness differences. With data for 905 species of terrestrial vertebrates distributed in the Isthmus of Tehuantepec, classified into five groups according to their taxonomy and dispersal ability, we calculated total dissimilarity and its additive partitioning as two components: dissimilarity derived from turnover and dissimilarity derived from richness differences. These indices were compared using fine (10 x 10 km, intermediate (20 x 20 km and coarse (40 x 40 km grain grids, and were tested for any correlations with geographic distance. The results showed that total dissimilarity is high for the terrestrial vertebrates in this region. Total dissimilarity, and dissimilarity due to turnover are correlated with geographic distance, and the patterns are clearer when the grain is fine, which is consistent with the distance-decay pattern of similarity. For all terrestrial vertebrates tested on the Isthmus of Tehuantepec both the dissimilarity derived from turnover and the dissimilarity resulting from richness differences make important contributions to total dissimilarity, and dispersal ability does not seem to influence the dissimilarity patterns. These findings support the idea that conservation efforts in this region require a system of interconnected protected areas that embrace the environmental, climatic and biogeographic heterogeneity of the area.

  18. Vertebrate dissimilarity due to turnover and richness differences in a highly beta-diverse region: the role of spatial grain size, dispersal ability and distance.

    Science.gov (United States)

    Calderón-Patrón, Jaime M; Moreno, Claudia E; Pineda-López, Rubén; Sánchez-Rojas, Gerardo; Zuria, Iriana

    2013-01-01

    We explore the influence of spatial grain size, dispersal ability, and geographic distance on the patterns of species dissimilarity of terrestrial vertebrates, separating the dissimilarity explained by species replacement (turnover) from that resulting from richness differences. With data for 905 species of terrestrial vertebrates distributed in the Isthmus of Tehuantepec, classified into five groups according to their taxonomy and dispersal ability, we calculated total dissimilarity and its additive partitioning as two components: dissimilarity derived from turnover and dissimilarity derived from richness differences. These indices were compared using fine (10 x 10 km), intermediate (20 x 20 km) and coarse (40 x 40 km) grain grids, and were tested for any correlations with geographic distance. The results showed that total dissimilarity is high for the terrestrial vertebrates in this region. Total dissimilarity, and dissimilarity due to turnover are correlated with geographic distance, and the patterns are clearer when the grain is fine, which is consistent with the distance-decay pattern of similarity. For all terrestrial vertebrates tested on the Isthmus of Tehuantepec both the dissimilarity derived from turnover and the dissimilarity resulting from richness differences make important contributions to total dissimilarity, and dispersal ability does not seem to influence the dissimilarity patterns. These findings support the idea that conservation efforts in this region require a system of interconnected protected areas that embrace the environmental, climatic and biogeographic heterogeneity of the area.

  19. A Development of Mathematical Connecting Ability of Students in Junior High School through a Problem-Based Learning with Course Review Horay Method

    Science.gov (United States)

    Malasari, P. N.; Nindiasari, H.; Jaenudin

    2017-02-01

    The aim of this research is to develop the lower ability of mathematical connection. The population of this research was the entire students of grade VII at one of state junior high school in Tangerang. The instrument used on the research is math connecting ability test. The results of the research showed that: 1) the average of post-test of mathematical connection in experimenting group is 74.78 and 66.61 for controlling group; 2) the average of gain of mathematical connection in experimenting group is 0.39 and 0.22 for controlling group. The conclusions of the research are: 1) the final result of mathematical connection in experimenting group with adequate criterion is getting way better than controlling group with poor criterion; 2) a developing mathematical connection in experimenting group with sufficient criterion is getting way better than controlling group with sufficient criterion. According to this study results, the author presented some suggestions that: 1) problem-based learning with course review horay method can be used as an alternative to improve mathematical connecting ability; 2) mathematics learning alternatives for implementing curriculum 2013; 3) continue with other aspect of research on a broader study.

  20. Facile and Low-Temperature Fabrication of Thermochromic Cr2O3/VO2 Smart Coatings: Enhanced Solar Modulation Ability, High Luminous Transmittance and UV-Shielding Function.

    Science.gov (United States)

    Chang, Tianci; Cao, Xun; Li, Ning; Long, Shiwei; Gao, Xiang; Dedon, Liv R; Sun, Guangyao; Luo, Hongjie; Jin, Ping

    2017-08-09

    In the pursuit of energy efficient materials, vanadium dioxide (VO2) based smart coatings have gained much attention in recent years. For smart window applications, VO2 thin films should be fabricated at low temperature to reduce the cost in commercial fabrication and solve compatibility problems. Meanwhile, thermochromic performance with high luminous transmittance and solar modulation ability, as well as effective UV shielding function has become the most important developing strategy for ideal smart windows. In this work, facile Cr2O3/VO2 bilayer coatings on quartz glasses were designed and fabricated by magnetron sputtering at low temperatures ranging from 250 to 350 °C as compared with typical high growth temperatures (>450 °C). The bottom Cr2O3 layer not only provides a structural template for the growth of VO2 (R), but also serves as an antireflection layer for improving the luminous transmittance. It was found that the deposition of Cr2O3 layer resulted in a dramatic enhancement of the solar modulation ability (56.4%) and improvement of luminous transmittance (26.4%) when compared to single-layer VO2 coating. According to optical measurements, the Cr2O3/VO2 bilayer structure exhibits excellent optical performances with an enhanced solar modulation ability (ΔTsol = 12.2%) and a high luminous transmittance (Tlum,lt = 46.0%), which makes a good balance between ΔTsol and Tlum for smart windows applications. As for UV-shielding properties, more than 95.8% UV radiation (250-400 nm) can be blocked out by the Cr2O3/VO2 structure. In addition, the visualized energy-efficient effect was modeled by heating a beaker of water using infrared imaging method with/without a Cr2O3/VO2 coating glass.

  1. PROBLEM-BASED MATHEMATICS TEACHING KITS INTEGRATED WITH ICT TO IMPROVE STUDENTS’ CRITICAL THINKING ABILITY IN JUNIOR HIGH SCHOOLS IN MEDAN

    Directory of Open Access Journals (Sweden)

    Waminton Rajagukguk

    2015-12-01

    Full Text Available Abstract: This study was aimed to develop a set of integrated problem-based mathematics teaching kits implemented with ICT to improve the critical thinking ability of junior high school students. The study used 4-D learning device development model (define, design, develop, disseminate. The data were collected through the observation of the learning process and students' activity, students' questionnaire responses, and a critical thinking ability test. The findings showed that mathematics teaching materials consisting of teaching kits as a teachers’ handbook based on ICT integrated problem-based materials completed with lesson plans, worksheets, and the use of media learning were appropriate to use.Based on the test results conducted in the field, the teaching kits can enhance the students' critical thinking ability. The findings showed that the average gain in two schools was in the range of g> 0.7, which means that the students' critical thinking ability belonged to the high category, while that of the third school was in the range of 0.3  g  0.7 at 0.62 which means the students’ critical thinking ability belonged to the fair category. Keywords: learning device, information communication technology (ICT, critical thinking PERANGKAT PEMBELAJARAN MATEMATIKA BERBASIS MASALAH TERINTEGRASI ICT UNTUK MENINGKATKAN KEMAMPUAN BERPIKIR KRITIS SISWA SMP KOTA MEDAN Abstrak: Penelitian ini bertujuan untuk mengembangkan perangkat pembelajaran matematika berbasis masalah terintegrasi dengan ICT untuk meningkatkan kemampuan berpikir kritis siswa SMP. Penelitian menggunakan model pengembangan perangkat pembelajaran model 4-D (define, design, develop, disseminate. Data penelitian diperoleh melalui pengamatan proses pembelajaran dan aktivitas siswa, angket respon siswa, dan tes kemampuan berpikir kritis. Hasil penelitian menunjukkan bahwa perangkat pembelajaran yang terdiri atas bahan ajar matematika sebagai buku pegangan guru berbasis masalah yang

  2. High ability education in Denmark

    DEFF Research Database (Denmark)

    Nissen, Poul; Baltzer, Kirsten; Kyed, Ole

    2007-01-01

    Chapter in peer refereed book on gifted education. The chapter offers a state of the art review on gifted education literature, and reports the results from a Danish study on giftedness revealing that 42 % had more problems and far more problems than typically reported by children and adolescents...

  3. Effects of in-season short-term aerobic and high-intensity interval training program on repeated sprint ability and jump performance in handball players.

    Science.gov (United States)

    Hermassi, Souhail; Ingebrigtsen, Jørgen; Schwesig, René; Fieseler, Georg; Delank, Karl-Stefan; Chamari, Karim; Shephard, Roy J; Chelly, Mohamed-Souhaiel

    2018-01-01

    This study examined the effects of a 7-week in-season aerobic and high-intensity interval-training program on performance tests linked to successful handball play (e.g., repeated sprint and jumping ability). Thirty participants (age 17.0±1.2 years, body mass 81.1±3.4 kg, height 1.82±0.07 m) performed a Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), a squat (SJ) and a Countermovement Jump Test (CMJ), as well as a repeated Sprint Ability Test (RSA). From this, maximal aerobic speed (MAS, reached at the end of the Yo-Yo IR1), jumping ability, best time in a single sprint trial (RSAbest), total time (RSATT) and the performance decrement (RSAdec) during all sprints were calculated. Later, subjects were randomly assigned to a control group (CG; N.=15) performing their normal training schedule (5 weekly sessions of ~90 minutes of handball training) or an experimental group (EG; N.=15). The EG performed two 30 min sessions per week of high-intensity aerobic exercises at 100-130% of MAS in addition to their normal training schedule. A significant improvement in MAS (d=4.1), RSAbest (d=1.9), RSATT (d=1.5) and RSAdec (d=2.3) after the training period was demonstrated. Also, significant interaction effects (time x group) were found for all parameters as the EG significantly improved performances in all tests after training. The greatest interaction effects were observed in MAS (η2=0.811) and CMJ (η2=0.759). No relevant changes in test performances were found in the CG (mean d=-0.02). These results indicate that individually speed-controlled aerobic and interval training is effective for improving specific handball performance.

  4. Ultrasonic assisted rapid synthesis of high uniform super-paramagnetic microspheres with core-shell structure and robust magneto-chromatic ability

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenyan, E-mail: wiseyanyan@jit.edu.cn [College of Material Engineering, Jinling Institute of technology, Nanjing (China); Chen, Jiahua [College of Material Engineering, Jinling Institute of technology, Nanjing (China); Wang, Wei [Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing (China); School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, Nanjing (China); Lu, GongXuan [State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000 (China); Hao, Lingyun [College of Material Engineering, Jinling Institute of technology, Nanjing (China); Ni, Yaru; Lu, Chunhua; Xu, Zhongzi [Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing (China); State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing (China)

    2017-03-15

    Super-paramagnetic core-shell microspheres were synthesized by ultrasonic assisted routine under low ultrasonic irradiation powers. Compared with conventional routine, ultrasonic effect could not only improve the uniformity of the core-shell structure of Fe{sub 3}O{sub 4}@SiO{sub 2}, but shorten the synthesis time in large scale. Owing to their hydrophilicity and high surface charge, the Fe{sub 3}O{sub 4}@SiO{sub 2} microspheres could be dispersed well in distilled water to form homogeneous colloidal suspension. The suspensions have favorable magneto-chromatic ability that they sensitively exhibit brilliant colorful ribbons by magnetic attraction. The colorful ribbons, which distributed along the magnetic lines, make morphology of the magnetic fields become “visible” to naked eyed. Those colorful ribbons originate from strong magnetic interaction between the microspheres and magnetic fields. Furthermore, the magneto-chromatic performance is reversible as the colorful ribbons vanished rapidly with the removing of magnetic fields. The silica layer effectively enhanced the acid resistance and surface-oxidation resistance of theFe{sub 3}O{sub 4}@SiO{sub 2} microspheres, so they could exhibit stable magnetic nature and robust magneto-chromatic property in acid environment. - Graphical abstract: The Graphical abstract shows the sensitive magneto-chromatic ability, the acid resistance ability as well as the magneto-chromatic mechanism of the Fe{sub 3}O{sub 4} and Fe{sub 3}O{sub 4}@SiO{sub 2} suspension. - Highlights: • Sensitive and reversible robust magneto-chromatic property under magnetic attraction. • Morphology of magnetic field “visible” to naked eyes. • Enhance acid resistance and surface-oxidation resistance. • Ultrasonic effect largely shorten the synthesis time of high uniform microspheres.

  5. Model program for the recruitment and preparation of high ability elementary mathematics/science teachers: A collaborative project among scientists, teacher educators and classroom teachers

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    This teacher education program will provide a model for recruiting, educating and retaining high ability students to become mathematics and science lead teachers in elementary schools. The quality experiences and support provided these students will help them develop the knowledge and attitudes necessary to provide leadership for elementary mathematics and science programs. Students will have research experiences at the Ames Laboratory, high quality field experiences with nationally recognized mathematics and science teachers in local schools and opportunities to meaningfully connect these two experiences. This program, collaboratively designed and implemented by scientists, teacher educators and classroom teachers, should provide a replicatable model for other teacher education institutions. In addition, materials developed for the project should help other laboratories interface more effectively with K-8 schools and help other teacher education programs incorporate real science and mathematics experience into their curriculum.

  6. Ability of Nontraditional Risk Factors and Inflammatory Biomarkers for Cardiovascular Disease to Identify High Cardiometabolic Risk in Adolescents: Results From the LabMed Physical Activity Study.

    Science.gov (United States)

    Agostinis-Sobrinho, César; Ruiz, Jonatan R; Moreira, Carla; Abreu, Sandra; Lopes, Luís; Oliveira-Santos, José; Mota, Jorge; Santos, Rute

    2017-11-22

    Then objective of this study was to evaluate the ability of several nontraditional cardiometabolic and inflammatory biomarkers in identifying high cardiometabolic risk in adolescents. A cross-sectional study was conducted with 529 Portuguese adolescents (267 girls) aged 14.3 ± 1.7 years. A clustered cardiometabolic risk score (body fat percentage, systolic blood pressure, ratio of total cholesterol to high-density lipoprotein cholesterol, triglycerides, homeostatic model assessment of insulin resistance, and negative values of cardiorespiratory fitness) was computed. The nontraditional cardiometabolic biomarkers assessed were complement factors (C3 and C4), C-reactive protein (CRP), fibrinogen, leptin, white blood cells (WBCs), albumin, interleukin-6, and a clustered score of inflammatory biomarkers (InflaScore) (C3, C4, CRP, fibrinogen, and leptin). Receiver operating characteristic curves analyses showed that C3, C4, CRP, fibrinogen, leptin, and the InflaScore were able to present discriminatory ability in identifying an unfavorable cardiometabolic profile in both girls and boys (p cardiometabolic risk, independent of age, pubertal stage, socioeconomic status, or adherence to a Mediterranean diet (p cardiometabolic risk in both sexes and WBC in boys. In addition, the clustered inflammatory biomarkers seem to have a better diagnostic accuracy in identifying an unfavorable cardiometabolic profile than single biomarkers. Such biomarkers may have utility in motivating health professionals, public health workers, and adolescents' families toward lifestyle changes, improving prevention efforts early in life. Copyright © 2017 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  7. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T.

    Directory of Open Access Journals (Sweden)

    Xiang Guo

    Full Text Available Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM and Ethyl Violet (25 μM, respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions.

  8. Emotional Abilities in Children with Oppositional Defiant Disorder (ODD): Impairments in Perspective-Taking and Understanding Mixed Emotions are Associated with High Callous-Unemotional Traits.

    Science.gov (United States)

    O'Kearney, Richard; Salmon, Karen; Liwag, Maria; Fortune, Clare-Ann; Dawel, Amy

    2017-04-01

    Most studies of emotion abilities in disruptive children focus on emotion expression recognition. This study compared 74 children aged 4-8 years with ODD to 45 comparison children (33 healthy; 12 with an anxiety disorder) on behaviourally assessed measures of emotion perception, emotion perspective-taking, knowledge of emotions causes and understanding ambivalent emotions and on parent-reported cognitive and affective empathy. Adjusting for child's sex, age and expressive language ODD children showed a paucity in attributing causes to emotions but no other deficits relative to the comparison groups. ODD boys with high levels of callous-unemotional traits (CU) (n = 22) showed deficits relative to low CU ODD boys (n = 25) in emotion perspective-taking and in understanding ambivalent emotions. Low CU ODD boys did not differ from the healthy typically developing boys (n = 12). Impairments in emotion perceptive-taking and understanding mixed emotions in ODD boys are associated with the presence of a high level of CU.

  9. Observed improvements in an intern's ability to initiate critical emergency skills in different cardiac arrest scenarios using high-fidelity simulation.

    Science.gov (United States)

    Starmer, David J; Duquette, Sean A; Guiliano, Dominic; Tibbles, Anthony; Miners, Andrew; Finn, Kevin; Stainsby, Brynne E

    2014-10-01

    Objective : The objective of this study was to report observed changes in an intern's ability to initiate critical emergency skills in different cardiac arrest scenarios with high-fidelity simulation over a 10-month period. Methods : One intern's performance was retrospectively analyzed using video recordings of 4 simulations at different stages in the training program. The key outcome was the duration of time expired for 4 critical skills, including activating the emergency response system, initiating cardiopulmonary resuscitation (CPR), using an automated external defibrillator (AED), and passively administrating oxygen. Results : The intern became more efficient in each subsequent simulation for activating the emergency response system and initiating CPR. The time to use the AED stayed relatively constant. The administration of oxygen was inconsistent. Conclusion : An improvement in the speed of applying emergency critical skills was observed with this intern. These improvements in skill may improve patient outcomes and survival rates. We propose further educational research with high-fidelity simulation in the area of assessing emergency skills.

  10. Effects of fragility and reduced glass transition temperature on the glass formation ability of amorphous alloys

    Science.gov (United States)

    Xu, Xiao-Jin; Long, Zhi-Lin; Liu, Wei; Liao, Guang-Kai

    2017-11-01

    In this paper, based on the reduced glass transition temperature ({{T}rg} ) proposed by Turnbull and the relation between the glass-forming ability (GFA) and the short-range bond ordering of liquids demonstrated by Tanaka, a detailed analysis on the specific roles of {{T}rg} and fragility of the glass forming liquid (m) in characterizing the GFA has been conducted, and then a novel GFA parameter α [=2/3× (100{{T}rg}{)}-(16/100)× m=67{{T}rg}-0.16m] was put forward. This new GFA parameter α , which increases with a decrease in the critical cooling rate (R c) for glass formation, is a complex function of {{T}rg} and m. The relationship between R c and the parameter α was identified and verified using available literature data for broad range of amorphous alloys with widely varying GFA. The correlation coefficient (R 2) of 0.9 clearly shows an excellent correlation between GFA and the parameter α and that α is a more superior indicator compared to currently reported similar GFA parameters.

  11. Novel effects of dapagliflozin on epicardial adipose tissue with insulin resistance, high levels of inflammatory chemokines production and low differentiation ability.

    Science.gov (United States)

    Díaz-Rodríguez, Esther; Agra, Rosa M; Fernández, Ángel L; Adrio, B; García-Caballero, Tomás; González-Juanatey, José R; Eiras, Sonia

    2017-09-11

    In patients with cardiovascular disease, epicardial adipose tissue (EAT) is characterized by insulin resistance, high pro-inflammatory chemokines and low differentiation ability. Since dapagliflozin reduces body fat and cardiovascular events in diabetic patients, we wanted to know its effect on EAT and subcutaneous adipose tissue (SAT). Adipose samples were obtained from 52 patients undergoing heart surgery. Sodium-glucose cotransporter 2 (SGLT2) expression was determined by real time PCR (n = 20), Western blot and immunohistochemistry. Fat explants (n = 21) were treated with dapagliflozin and/or insulin. Glucose, free fatty acid, adipokines levels (by array) were measured in their secretomes which were tested on human coronary endothelial cells by wound healing assays. The effect of dapagliflozin effect on levels of glucose transporters in EAT explants was analysed by Western blot. Glucose uptake was also measured by fluorescence glucose (6NBDG) of differentiated stromal vascular cells from fat pads (n = 11). Finally, dapagliflozin-induced adipocytes differentiation was analysed by AdipoRed staining and perilipin levels. Results revealed SGLT2 expression in EAT. Dapagliflozin increased glucose uptake (20.95 ± 4.4 mg/dL vs. 12.97 ± 4.1 mg/dL; p effect on the healing of human coronary artery endothelial cells) and improved the differentiation of EAT cells. These results suggest a new protective pathway for this drug on EAT from patients with cardiovascular disease.

  12. Normal Health-Related Quality of Life and Ability to Work Twenty-nine Years After in Situ Arthrodesis for High-Grade Isthmic Spondylolisthesis.

    Science.gov (United States)

    Joelson, Anders; Hedlund, Rune; Frennered, Karin

    2014-06-18

    The purpose of this mixed prospective and retrospective case series was to evaluate the long-term health-related quality of life and physical disability after in situ arthrodesis for high-grade isthmic spondylolisthesis. Thirty-five of forty consecutive patients who had in situ spinal arthrodesis for high-grade isthmic spondylolisthesis at a mean age of fifteen years (range, nine to twenty-five years) completed validated questionnaires (Short Form-36 [SF-36], EuroQol-5 Dimensions [EQ-5D], Zung depression scale, Oswestry disability index [ODI], Million score, and back and leg pain visual analog scale [VAS]) and underwent physical examination twenty-nine years (range, twenty-three to thirty-five years) after surgery. The mean age at the time of follow-up was forty-three years (range, thirty-seven to fifty-one years). In the absence of a formal control group, the scores on the SF-36 and EQ-5D were compared with Swedish normative data. The proportion of patients at work was compared with an age-matched control group derived from official statistics of Sweden. The Million score at the long-term follow-up was compared with the corresponding results at the mid-term follow-up of the same patients at a mean age of twenty-two years. The scores on the SF-36 and EQ-5D were similar to the scores of the general Swedish population. The mean Zung depression scale score was 30 (range, 20 to 52), the mean ODI score was 10 (range, 0 to 34), the mean back pain VAS score was 13 (range, 0 to 72), and the mean leg pain VAS score was 9 (range, 0 to 60). The Million score averaged 28 (range, 0 to 109) and was slightly worsened compared with the score of 19 (range, 0 to 94) at the mid-term follow-up (p = 0.034). The proportion of patients at work was the same as that for the age-matched general Swedish population. Our study shows good outcomes in health-related quality of life, disability, pain, and ability to work at up to twenty-nine years after in situ lumbar spine arthrodesis for high

  13. Comparison of the Ability of Different Clinical Treatment Scores to Estimate Prognosis in High-Risk Early Breast Cancer Patients: A Hellenic Cooperative Oncology Group Study

    Science.gov (United States)

    Pliarchopoulou, Kyriaki; Wirtz, Ralph M.; Alexopoulou, Zoi; Zagouri, Flora; Veltrup, Elke; Timotheadou, Eleni; Gogas, Helen; Koutras, Angelos; Lazaridis, Georgios; Christodoulou, Christos; Pentheroudakis, George; Laskarakis, Apostolos; Arapantoni-Dadioti, Petroula; Batistatou, Anna; Sotiropoulou, Maria; Aravantinos, Gerasimos; Papakostas, Pavlos; Kosmidis, Paris; Pectasides, Dimitrios; Fountzilas, George

    2016-01-01

    Background-Aim Early breast cancer is a heterogeneous disease, and, therefore, prognostic tools have been developed to evaluate the risk for distant recurrence. In the present study, we sought to develop a risk for recurrence score (RRS) based on mRNA expression of three proliferation markers in high-risk early breast cancer patients and evaluate its ability to predict risk for relapse and death. In addition the Adjuvant! Online score (AOS) was also determined for each patient, providing a 10-year estimate of relapse and mortality risk. We then evaluated whether RRS or AOS might possibly improve the prognostic information of the clinical treatment score (CTS), a model derived from clinicopathological variables. Methods A total of 1,681 patients, enrolled in two prospective phase III trials, were treated with anthracycline-based adjuvant chemotherapy. Sufficient RNA was extracted from 875 samples followed by multiplex quantitative reverse transcription-polymerase chain reaction for assessing RACGAP1, TOP2A and Ki67 mRNA expression. The CTS, slightly modified to fit our cohort, integrated the prognostic information from age, nodal status, tumor size, histological grade and treatment. Patients were also classified to breast cancer subtypes defined by immunohistochemistry. Likelihood ratio (LR) tests and concordance indices were used to estimate the relative increase in the amount of information provided when either RRS or AOS is added to CTS. Results The optimal RRS, in terms of disease-free survival (DFS) and overall survival (OS), was based on the co-expression of two of the three evaluated genes (RACGAP1 and TOP2A). CTS was prognostic for DFS (p3 positive nodes (LR-Δχ2 23.9, p3 positive nodes. PMID:27695115

  14. A strain of Saccharomyces cerevisiae evolved for fermentation of lignocellulosic biomass displays improved growth and fermentative ability in high solids concentrations and in the presence of inhibitory compounds

    Directory of Open Access Journals (Sweden)

    Hawkins Gary M

    2011-11-01

    Full Text Available Abstract Background Softwoods are the dominant source of lignocellulosic biomass in the northern hemisphere, and have been investigated worldwide as a renewable substrate for cellulosic ethanol production. One challenge to using softwoods, which is particularly acute with pine, is that the pretreatment process produces inhibitory compounds detrimental to the growth and metabolic activity of fermenting organisms. To overcome the challenge of bioconversion in the presence of inhibitory compounds, especially at high solids loading, a strain of Saccharomyces cerevisiae was subjected to evolutionary engineering and adaptation for fermentation of pretreated pine wood (Pinus taeda. Results An industrial strain of Saccharomyces, XR122N, was evolved using pretreated pine; the resulting daughter strain, AJP50, produced ethanol much more rapidly than its parent in fermentations of pretreated pine. Adaptation, by preculturing of the industrial yeast XR122N and the evolved strains in 7% dry weight per volume (w/v pretreated pine solids prior to inoculation into higher solids concentrations, improved fermentation performance of all strains compared with direct inoculation into high solids. Growth comparisons between XR122N and AJP50 in model hydrolysate media containing inhibitory compounds found in pretreated biomass showed that AJP50 exited lag phase faster under all conditions tested. This was due, in part, to the ability of AJP50 to rapidly convert furfural and hydroxymethylfurfural to their less toxic alcohol derivatives, and to recover from reactive oxygen species damage more quickly than XR122N. Under industrially relevant conditions of 17.5% w/v pretreated pine solids loading, additional evolutionary engineering was required to decrease the pronounced lag phase. Using a combination of adaptation by inoculation first into a solids loading of 7% w/v for 24 hours, followed by a 10% v/v inoculum (approximately equivalent to 1 g/L dry cell weight into 17

  15. Resveratrol analogues like piceatannol are potent antioxidants as quantitatively demonstrated through the high scavenging ability against reactive oxygen species and methyl radical.

    Science.gov (United States)

    Sueishi, Yoshimi; Nii, Risako; Kakizaki, Naru

    2017-12-01

    Resveratrol (RSV) analogues have attracted much attention because of the expected health functions including antioxidant activities. We have carried out a quantitative determination of the scavenging abilities of six trans-RSV analogues against various reactive oxygen species and methyl radical (hydroxyl radical, superoxide, alkoxyl radical, peroxyl radical, methyl radical, and singlet oxygen). RSV analogues are in general more potent scavenger than the parent RSV. Furthermore, piceatannol (PIC) having two OH groups in the ortho position of resveratrol was found to show 11 times higher scavenging ability against peroxyl radical than parent resveratrol. With the aid of previous theoretical studies, the enhanced antioxidant ability was interpreted based on the effects of substituent that modifies the original resveratrol structure and function. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The effect of a combined high-intensity plyometric and speed training program on the running and jumping ability of male handball players.

    Science.gov (United States)

    Cherif, Monsef; Said, Mohamed; Chaatani, Sana; Nejlaoui, Olfa; Gomri, Daghbaji; Abdallah, Aouidet

    2012-03-01

    The aim of this study was to investigate the effect of a combined program including sprint repetitions and drop jump training in the same session on male handball players. Twenty-two male handball players aged more than 20 years were assigned into 2 groups: experimental group (n=11) and control group (n=11). Selection was based on variables "axis" and "lines", goalkeepers were not included. The experimental group was subjected to 2 testing periods (test and retest) separated by 12 weeks of an additional combined plyometric and running speed training program. The control group performed the usual handball training. The testing period comprised, at the first day, a medical checking, anthropometric measurements and an incremental exercise test called yo-yo intermittent recovery test. 2 days later, participants performed the Repeated Sprint Ability test (RSA), and performed the Jumping Performance using 3 different events: Squat jump (SJ), Countermovement jump without (CMJ) and with arms (CMJA), and Drop jump (DJ). At the end of the training period, participants performed again the repeated sprint ability test, and the jumping performance. The conventional combined program improved the explosive force ability of handball players in CMJ (P=0.01), CMJA (P=0.01) and DJR (P=0.03). The change was 2.78, 2.42 and 2.62% respectively. No significant changes were noted in performances of the experimental group at the squat jump test and the drop jump with the left leg test. The training intervention also improved the running speed ability of the experimental group (P=0.003). No statistical differences were observed between lines or axes. Additional combined training program between sprint repetition and vertical jump in the same training session positively influence the jumping ability and the sprint ability of handball players.

  17. Effect of C and Ce addition on the microstructure and magnetic property of the mechanically alloyed FeSiBAlNi high entropy alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jing [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Axinte, Eugen [Gh. Asachi Technical University of Iasi, Faculty of Machine Manufacturing & Industrial Management, 59 A, Prof. Dimitrie Mangeron Blvd. (Romania); Zhao, Zhengfeng [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Wang, Yan, E-mail: mse_wangy@ujn.edu.cn [School of Materials Science and Engineering, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China); Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, No. 336, West Road of Nan Xinzhuang, Jinan 250022 (China)

    2016-09-15

    The effects of elemental addition, C and Ce, on the microstructure, thermal property and magnetic property of mechanically alloyed FeSiBAlNi (based-W5) high entropy alloys (HEAs) have been investigated in depth in the present work. The amorphous HEAs have been successfully fabricated by mechanical alloying. The results reveal that Ce addition obviously shortens the formation time of fully amorphous phase, therefore leading to the enhanced glass forming ability (GFA) of the based-W5. The final products of as-milled FeSiBAlNiC alloy consist of the main amorphous phase and a small amount of Si nanocrystals. In addition, C and Ce addition are both beneficial to enhance the thermal stability. The coercivity force (H{sub c}) of the tested samples lies in the range of 50–378 Oe, suggesting the semi-hard magnetic property. The saturation magnetization (M{sub s}) becomes decreased with increasing the milling time. C addition effectively increases M{sub s} exhibiting the good magnetic property, however, Ce addition presents the negative effect. It should be noted that the amorphous phase tends to be formed when the radius ratio (R{sub r}) is larger than 1, and the GFA is enhanced with increasing R{sub r} and valence electron concentration. - Highlights: • FeSiBAlNi (C, Ce) amorphous HEAs have been fabricated by mechanical alloying. • The effects of C and Ce addition were investigated. • Ce addition exhibits a remarkably enhanced effect on glass forming ability (GFA). • C and Ce additions are beneficial to enhance thermal stability.

  18. Trajectories of Self-Perceived Math Ability, Utility Value and Interest across Middle School as Predictors of High School Math Performance

    Science.gov (United States)

    Petersen, Jennifer Lee; Hyde, Janet Shibley

    2017-01-01

    Although many studies have documented developmental change in mathematics motivation, little is known about how these trends predict math performance. A sample of 288 participants from the United States reported their perceived math ability, math utility value and math interest in 5th, 7th and 9th grades. Latent growth curve models estimated…

  19. The Effects of Modality and Multimedia Comprehension on the Performance of Students with Varied Multimedia Comprehension Abilities when Exposed to High Complexity, Self-Paced Multimedia Instructional Materials

    Science.gov (United States)

    Al-Abbasi, Daniah

    2012-01-01

    Poor multimedia comprehenders suffer from a decreased ability in comprehending complex textual and pictorial materials (Maki & Maki, 2002). This deficit will lead to an overloaded working memory and consequently decreased performance (Carretti, Borella, Cornoldi, & De Beni, 2009). The purpose of this research study was to examine the effects of…

  20. WISC-IV Profile in High-Functioning Autism Spectrum Disorders: Impaired Processing Speed Is Associated with Increased Autism Communication Symptoms and Decreased Adaptive Communication Abilities

    Science.gov (United States)

    Oliveras-Rentas, Rafael E.; Kenworthy, Lauren; Roberson, Richard B.; Martin, Alex; Wallace, Gregory L.

    2012-01-01

    Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the…

  1. A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials

    Science.gov (United States)

    Soinila, E.; Pihlajamäki, T.; Bossuyt, S.; Hänninen, H.

    2011-07-01

    An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr55Cu30Al10Ni5 directly into rods up to ø 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.

  2. Exceptional cognitive ability: the phenotype.

    Science.gov (United States)

    Lubinski, David

    2009-07-01

    Characterizing the outcomes related to the phenotype of exceptional cognitive abilities has been feasible in recent years due to the availability of large samples of intellectually precocious adolescents identified by modern talent searches that have been followed-up longitudinally over multiple decades. The level and pattern of cognitive abilities, even among participants within the top 1% of general intellectual ability, are related to differential developmental trajectories and important life accomplishments: The likelihood of earning a doctorate, earning exceptional compensation, publishing novels, securing patents, and earning tenure at a top university (and the academic disciplines within which tenure is most likely to occur) all vary as a function of individual differences in cognitive abilities assessed decades earlier. Individual differences that distinguish the able (top 1 in 100) from the exceptionally able (top 1 in 10,000) during early adolescence matter in life, and, given the heritability of general intelligence, they suggest that understanding the genetic and environmental origins of exceptional abilities should be a high priority for behavior genetic research, especially because the results for extreme groups could differ from the rest of the population. In addition to enhancing our understanding of the etiology of general intelligence at the extreme, such inquiry may also reveal fundamental determinants of specific abilities, like mathematical versus verbal reasoning, and the distinctive phenotypes that contrasting ability patterns are most likely to eventuate in at extraordinary levels.

  3. [Does the islet of ability on visuospatial tasks in children with high-functioning autism really indicate a deficit in global processing?].

    Science.gov (United States)

    Planche, P; Lemonnier, E

    2011-02-01

    The literature on autism reports regularly the presence of a peak of ability on the visuospatial tasks. The classic interpretation of this result refers to the theoretical model proposed by Frith (1989) who evokes a "lack of central coherence" in persons with autism that is a deficit in the mobilization of global processing. The research reported here has for objective to propose a reflection on the relevance of this model by asking the following question: is global processing impaired in autism or simply not mobilized for the benefit of the almost exclusive appeal to local treatment? A group of children with high-functioning autism was compared with normally developping children (n=15 per group), matched on age and global level of intelligence. The clinical group, 14 boys and a girl, had received a diagnosis of typical autism according to the criteria of the ICD-10 (F84.0) confirmed by ADI-R. These children all used a functional language at the time of inclusion within the study, however all of them initially presented a delay in language (mean age: 8 years and 6 months; mean total IQ: 98.07). The typically developping group, 12 boys and three girls, were from ordinary school (mean age: 9 years, mean total IQ: 106.2). Two tasks were employed for the collection of data: the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was used to estimate the total-, verbal- and performance-IQ scores of every child and to match both groups. It also permitted the evaluation and comparison of the performances of the children on the following visuospatial tasks: "picture completion", "object assembly" and "block design". The NEPSY scale permitted the estimation and comparison of the levels of performance of both groups on visuospatial functions. In terms of scores, the tasks of the WISC-III, requiring visiospatial processing as well as the global evaluation of the visiospatial functions with the NEPSY, showed the absence of significant differences between children

  4. Low melting high lithia glass compositions and methods

    Science.gov (United States)

    Jantzen, Carol M.; Pickett, John B.; Cicero-Herman, Connie A.; Marra, James C.

    2000-01-01

    The invention relates to methods of vitrifying waste and for lowering the melting point of glass forming systems by including lithia formers in the glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total glass forming oxides. The lithia is typically included as a replacement for alkali oxide glass formers that would normally be present in a particular glass forming system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste streams, sludge solids, mixtures of aqueous supernate and sludge solids, combinations of spent filter aids from waste water treatment and waste sludges, supernate alone, incinerator ash, incinerator offgas blowdown, or combinations thereof, geological mine tailings and sludges, asbestos, inorganic filter media, cement waste forms in need of remediation, spent or partially spent ion exchange resins or zeolites, contaminated soils, lead paint, etc. The decrease in melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during vitrification.

  5. Predictive abilities of the STOP-Bang and Epworth Sleepiness Scale in identifying sleep clinic patients at high risk for obstructive sleep apnea.

    Science.gov (United States)

    Vana, Kimberly D; Silva, Graciela E; Goldberg, Rochelle

    2013-02-01

    This study compared the predictive abilities of the STOP-Bang and Epworth Sleepiness Scale (ESS) for screening sleep clinic patients for obstructive sleep apnea (OSA) and sleep-disordered breathing (SDB). Forty-seven new adult patients without previous diagnoses of OSA or SDB were administered the STOP-Bang and ESS and were assigned to OSA or SDB risk groups based on their scores. STOP-Bang responses were scored with two Body Mass Index cut points of 35 and 30 kg/m(2) (SB35 and SB30). The tools' predictive abilities were determined by comparing patients' predicted OSA and SDB risks to their polysomnographic results. The SB30 correctly identified more patients with OSA and SDB than the ESS alone. The ESS had the highest specificity for OSA and SDB. Copyright © 2012 Wiley Periodicals, Inc.

  6. Influence of Learning Strategies STAD Using Portfolio Assessment and Academic Ability to Concept Training Junior High School Students in Biology Education

    Directory of Open Access Journals (Sweden)

    Puspani Puspani

    2014-06-01

    Full Text Available Pengaruh Strategi Pembelajaran STAD Menggunakan Penilaian Portofolio dan Kemampuan Akademik terhadap Pemahaman Konsep Siswa SMP pada Pembelajaran Biologi Abstract: This study is a quasi-experimental research (quasi experimental which aims to: (1 examine the effect of STAD learning strategies using a portfolio assessment to the understanding of concepts and critical thinking skills, (2 test the effect of academic ability to understanding of concepts and critical thinking skills students, (3 test the interaction effect of STAD strategy using portfolio assessment and academic ability to the understanding of concepts and critical thinking skills of students. Research using the draft "non-pretest-posttest control group design equivalent" version 2x2 factorial. Data analysis to test for normality and homogeneity, followed by analysis of covariance (Anacova and a further test LSD. The study population is class VIII SMPN 12 Balikpapan. Samples are 6 classes determined by random cluster sampling technique. The results showed: (1 there was an effect of STAD strategy using a portfolio assessment to the understanding of concepts and critical thinking skills of students, (2 no influence on the understanding of the concept of academic ability and critical thinking skills of students, (3 there is no interaction effect between strategy STAD using portfolio assessment and academic ability to the understanding of concepts and critical thinking skills of students. Key Words: STAD, portfolios, academic ability, understanding of the concept Abstrak: Penelitian ini merupakan penelitian eksperimen semu (quasi experiment yang bertujuan untuk: (1 menguji pengaruh strategi pembelajaran STAD dengan menggunakan penilaian portofolio terhadap pemahaman konsep dan kemampuan berpikir kritis, (2 menguji pengaruh kemampuan akade-mik terhadap pemahaman konsep dan kemampuan berpikir kritis siswa, (3 menguji pengaruh interaksi strategi pembelajaran STAD dengan menggunakan penilaian

  7. Experimental Evidence for a Glass forming "Stripe Liquid" in the Magnetic Ground State of La1.65Eu0.2Sr0.15CuO4

    OpenAIRE

    Simovic, B.; Hammel, P. C.; Hucker, M.; Buchner, B.; Revcolevschi, A.

    2002-01-01

    We report measurements of the longitudinal ($^{139}T_1^{-1}$) and transverse ($^{139}T_2^{-1}$) decay rates of the magnetization of $^{139}$La nuclei performed in a high quality single crystal of La$_{1.65}$Eu$_{0.2}$Sr$_{0.15}$CuO$_{4}$. We observe a dramatic slowing of the Cu 3d spins manifested as a sharp increase of both $^{139}T_1^{-1}$ and $^{139}T_2^{-1}$ below 30 K. We find that in this temperature range the fluctuations involve a unique time scale $\\tau $ which diverges as $(T-T_{\\rm...

  8. THE COMPARISON OF STUDENTS’ WRITING DESCRPTIVE TEXT ABILITY BY USING JIGSAW AND SCAFFOLDING TECHNIQUE IN EVEN SEMESTER AT GRADE X STATE SENIOR HIGH SCHOOL 1 SEPUTIH RAMAN ACADEMIC YEAR 2012/2013

    Directory of Open Access Journals (Sweden)

    Ni Putu Ayu Dian Anggraeni

    2013-05-01

    Full Text Available Writing as one of the four skills has always been as a part of the syllabus in teaching of English. The techniques presented as a solution in this research about writing ability are Jigsaw and Scaffolding technique. There are three problems of the study, (1 Is Jigsaw technique effective to improve students’ writing descriptive text ability? (2 Is Scaffolding technique effective to improve students’ writing descriptive text ability? (3 Is there any significant difference of students’ writing descriptive text ability by using Jigsaw and Scaffolding technique? The objective of this research is (1 To know whether Jigsaw technique is effective to improve students’ writing descriptive text ability. (2 To know whether Scaffolding technique is effective to improve students’ writing descriptive text ability. (3 To know whether there is any significant difference of students’ writing descriptive text ability by using Jigsaw and Scaffolding technique. The method of investigation is held through quantitative experimental research. The researchers uses modified pretest-posttest control group design. In this experiment, the employees control group pre test post test design. The researchers is conducted at the grade X of State Senior High School 1 Seputih Raman in academic year 2012/2013. The popolation in this research is 210 students. It is consist 7 classes and each class consist 30. The researchers takes 90 students from total population as the sample. 30 students as experiment class of Jigsaw, 30 students as experiment class of Scaffolding, and 30 as control class that matching based on classification of student level. And the researchers use cluster random sampling as technique sampling. To analyze data, the researchers uses One Way ANOVA. The researchers got the result of Ft 1% = 7.31 and Ft 5% = 4.08 and it seems that FO > Ft  1% and Ft  5% in which FO = 7.31 > Ft  1% = 7.31 and Ft  5% = 4.08. The criteria of One Way ANOVA is FO ≥ Ft

  9. Tests of Cognitive Ability

    Science.gov (United States)

    2005-12-01

    specific abilities while Ree and others (Olea & Ree, 1994; Ree, TESTS OF GENERAL COGNITIVE ABILITY 9 Carretta, & Doub , 1998/1999; Ree, Carretta...Ree, M. J., Carretta, T. R., & Doub , T. (1998/1999). A Test of Three Models of the Role of g and Prior Job Knowledge in the Acquisition of Subsequent

  10. Changes of the level of high-speed and power abilities of beach handball players of 14–15 years old as a result of the specially selective exercises

    Directory of Open Access Journals (Sweden)

    Helena Biykova

    2015-12-01

    Full Text Available Purpose: to determine changes of the level of high-speed and power abilities of beach handball players of 14–15 years old under the influence of the specially selective sets of exercises. Material and Methods: test exercises, one of which is recommended by the training program of CYSS of beach handball, two others were created proceeding from the content of the game activity in beach handball, the analysis of scientific and methodical literature, pedagogical testing, pedagogical experiment, methods of mathematical information processing were used for the definition of the level of development of high-speed and power abilities of beach handball players. Results: the analysis of scientific and methodical literature revealed gaps in questions of training of beach handball players, in particular in physical preparation. It moved us making the use of experience of the educational and training work in beach volleyball, to make sets of exercises, which are aimed at the development high-speed and power abilities of beach handball players. Conclusions: the positive reliable changes are received (t=2,19–2,32 at p≤0,05 of the level of high-speed and power abilities of players of 14-15 years old under the influence of the sets of exercises which are offered by us, allows us to recommend them for use in the educational and training process of beach handball players

  11. Innovative Allies: Spatial and Creative Abilities

    Science.gov (United States)

    Coxon, Steve V.

    2012-01-01

    Spatial and creative abilities are important for innovations in science, technology, engineering, and math (STEM) fields, but talents are rarely developed from these abilities by schools, including among gifted children and adolescents who have a high potential to become STEM innovators. This article provides an overview of each ability and makes…

  12. Learning anatomy enhances spatial ability.

    NARCIS (Netherlands)

    Vorstenbosch, M.A.T.M.; Klaassen, T.P.; Donders, A.R.T.; Kooloos, J.G.M.; Bolhuis, S.M.; Laan, R.F.J.M.

    2013-01-01

    Spatial ability is an important factor in learning anatomy. Students with high scores on a mental rotation test (MRT) systematically score higher on anatomy examinations. This study aims to investigate if learning anatomy also oppositely improves the MRT-score. Five hundred first year students of

  13. increased larval competitive ability without

    Indian Academy of Sciences (India)

    2016-06-01

    Jun 1, 2016 ... tion at high density should result in the increase of efficiency of conversion of food to biomass, and were better interpreted through the lens of α-selection. We show here that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolve greater competitive ability and pre-adult ...

  14. Learning Anatomy Enhances Spatial Ability

    Science.gov (United States)

    Vorstenbosch, Marc A. T. M.; Klaassen, Tim P. F. M.; Donders, A. R. T.; Kooloos, Jan G. M.; Bolhuis, Sanneke M.; Laan, Roland F. J. M.

    2013-01-01

    Spatial ability is an important factor in learning anatomy. Students with high scores on a mental rotation test (MRT) systematically score higher on anatomy examinations. This study aims to investigate if learning anatomy also oppositely improves the MRT-score. Five hundred first year students of medicine ("n" = 242, intervention) and…

  15. Peer Mediated Instruction and Intervention (PMII type Classwide Peer Tutoring (CWPT and Academics Ability of Natural Science-Biology in Vocational High School

    Directory of Open Access Journals (Sweden)

    Hamsiah Hamsiah

    2014-06-01

    Full Text Available Peer Mediated Instruction and Intervention (PMII tipe Classwide Peer Tutoring (CWPTdan Kemampuan Akademik pada Pembelajaran IPA Biologi SMK Abstract: Learning science in SMK 1 Bontang still dominated by conventional learning strategy is a method of learning with lecture. This has an impact on learning outcomes of cognitive science that tends biology is still low because the students have not been trained become independent learners, thus learning innovation PMII CWPT types can be used as a breakthrough to develop the cognitive learning. This study was conducted to determine the application CWPT strategies and academic skills in science teaching vocational Biology. Quasi-experimental research with pretest-posttest design Nonequivalent Control Group. Results of the study, namely: (1 there CWPT effect on the cognitive learning, (2 no influence academic ability to cognitive learning outcomes, and (3 there is no interaction effect between learning strategy and the academic ability toward the cognitive learning. Key Words: peer-mediated instruction and intervention, classwide peer tutoring, academic skills, cognitive learning outcomes Abstrak: Pembelajaran IPA di SMKN 1 Bontang masih didominasi dengan strategi belajar konvensio-nal yaitu metode belajar dengan ceramah. Hal ini berdampak terhadap hasil belajar kognitif IPA biolo-gi yang cendrung masih rendah karena siswa belum terlatih menjadi pebelajar yang mandiri, sehingga inovasi pembelajaran PMII tipe CWPT dapat digunakan sebagai terobosan untuk mengembangkan  hasil belajar kognitif. Penelitian ini dilakukan untuk mengetahui penerapan strategi CWPT dan kemam-puan akademik pada pembelajaran IPA Biologi SMK. Penelitian eksperimen semu dengan rancangan pretest-posttest Nonequivalent Control Group. Hasil penelitian, yaitu: (1 ada pengaruh CWPT ter-hadap hasil belajar kognitif,  (2 ada  pengaruh  kemampuan akademik terhadap hasil belajar kognitif, dan (3 tidak ada  pengaruh interaksi antara

  16. Glass Transition, Crystallization of Glass-Forming Melts, and Entropy

    Directory of Open Access Journals (Sweden)

    Jürn W. P. Schmelzer

    2018-02-01

    Full Text Available A critical analysis of possible (including some newly proposed definitions of the vitreous state and the glass transition is performed and an overview of kinetic criteria of vitrification is presented. On the basis of these results, recent controversial discussions on the possible values of the residual entropy of glasses are reviewed. Our conclusion is that the treatment of vitrification as a process of continuously breaking ergodicity with entropy loss and a residual entropy tending to zero in the limit of zero absolute temperature is in disagreement with the absolute majority of experimental and theoretical investigations of this process and the nature of the vitreous state. This conclusion is illustrated by model computations. In addition to the main conclusion derived from these computations, they are employed as a test for several suggestions concerning the behavior of thermodynamic coefficients in the glass transition range. Further, a brief review is given on possible ways of resolving the Kauzmann paradox and its implications with respect to the validity of the third law of thermodynamics. It is shown that neither in its primary formulations nor in its consequences does the Kauzmann paradox result in contradictions with any basic laws of nature. Such contradictions are excluded by either crystallization (not associated with a pseudospinodal as suggested by Kauzmann or a conventional (and not an ideal glass transition. Some further so far widely unexplored directions of research on the interplay between crystallization and glass transition are anticipated, in which entropy may play—beyond the topics widely discussed and reviewed here—a major role.

  17. Thermodynamic and relative approach to compute glass-forming ...

    Indian Academy of Sciences (India)

    Obeying to the non-dimensional analysis rules, we introduce a neglected (in all prior thermodynamic models) characteristic: the isobaric heat capacity (p) of oxides, and ... Moreover, the value intervals confirm the oxides classification into three groups (forming, intermediate and modifier) and sorting of the former ones in ...

  18. String model for the dynamics of glass-forming liquids.

    Science.gov (United States)

    Pazmiño Betancourt, Beatriz A; Douglas, Jack F; Starr, Francis W

    2014-05-28

    We test the applicability of a living polymerization theory to describe cooperative string-like particle rearrangement clusters (strings) observed in simulations of a coarse-grained polymer melt. The theory quantitatively describes the interrelation between the average string length L, configurational entropy Sconf, and the order parameter for string assembly Φ without free parameters. Combining this theory with the Adam-Gibbs model allows us to predict the relaxation time τ in a lower temperature T range than accessible by current simulations. In particular, the combined theories suggest a return to Arrhenius behavior near Tg and a low T residual entropy, thus avoiding a Kauzmann "entropy crisis."

  19. Linking Equilibrium and Nonequilibrium Dynamics in Glass-Forming Systems

    DEFF Research Database (Denmark)

    Mauro, John C.; Guo, Xiaoju; Smedskjær, Morten Mattrup

    Understanding nonequilibrium glassy dynamics is of great scientific and technological importance. However, prediction of the temperature, thermal history, and composition dependence of nonequilibrium viscosity is challenging due to the noncrystalline and nonergodic nature of the glassy state. Here......, we show that the nonequilibrium glassy dynamics are intimately connected with the equilibrium liquid dynamics. This is accomplished by deriving a new functional form for the thermal history dependence of nonequilibrium viscosity, which is validated against experimental measurements of industrial...... silicate glasses and computed viscosities for selenium over a wide range of conditions. Since the temperature and composition dependence of liquid viscosity can be predicted using temperature-dependent constraint theory, our work also opens the possibility to improve understanding of the physics...

  20. A high-enrollment course-based undergraduate research experience improves student conceptions of scientific thinking and ability to interpret data.

    Science.gov (United States)

    Brownell, Sara E; Hekmat-Scafe, Daria S; Singla, Veena; Chandler Seawell, Patricia; Conklin Imam, Jamie F; Eddy, Sarah L; Stearns, Tim; Cyert, Martha S

    2015-01-01

    We present an innovative course-based undergraduate research experience curriculum focused on the characterization of single point mutations in p53, a tumor suppressor gene that is mutated in more than 50% of human cancers. This course is required of all introductory biology students, so all biology majors engage in a research project as part of their training. Using a set of open-ended written prompts, we found that the course shifts student conceptions of what it means to think like a scientist from novice to more expert-like. Students at the end of the course identified experimental repetition, data analysis, and collaboration as important elements of thinking like a scientist. Course exams revealed that students showed gains in their ability to analyze and interpret data. These data indicate that this course-embedded research experience has a positive impact on the development of students' conceptions and practice of scientific thinking. © 2015 S. E. Brownell et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  1. Gait rehabilitation with a high tech platform based on virtual reality conveys improvements in walking ability of children suffering from acquired brain injury.

    Science.gov (United States)

    Biffi, E; Beretta, E; Diella, E; Panzeri, D; Maghini, C; Turconi, A C; Strazzer, S; Reni, G

    2015-01-01

    The Gait Real-time Analysis Interactive Lab (GRAIL) is an instrumented multi-sensor platform based on immersive virtual reality for gait training and rehabilitation. Few studies have been included GRAIL to evaluate gait patterns in normal and disabled people and to improve gait in adults, while at our knowledge no evidence on its use for the rehabilitation of children is available. In this study, 4 children suffering from acquired brain injury (ABI) underwent a 5 session treatment with GRAIL, to improve walking and balance ability in engaging VR environments. The first and the last sessions were partially dedicated to gait evaluation. Results are promising: improvements were recorded at the ankle level, selectively at the affected side, and at the pelvic level, while small changes were measured at the hip and knee joints, which were already comparable to healthy subjects. All these changes also conveyed advances in the symmetry of the walking pattern. In the next future, a longer intervention will be proposed and more children will be enrolled to strongly prove the effectiveness of GRAIL in the rehabilitation of children with ABI.

  2. Development of arithmetical abilities

    Directory of Open Access Journals (Sweden)

    Tatjana Levstek

    2014-02-01

    Full Text Available Arithmetic (from the word 'arithmos' which means 'numbers' is an elementary branch of mathematics. Numeracy is essential for understanding mathematics, so the development of arithmetic abilities has been an area of scientific research for a long time. Recent research has shown that the development of arithmetic abilities is not based only on gaining experience and learning. Some arithmetic abilities, especially the sense of quantity, are innate. Even babies are able to distinguish between groups with different number of elements and they perceive numeracy amodally. Six-month-olds distinguish between two groups with the numeracy ratio of 1 : 2. With age this ratio improves rapidly. Five-year-old children already distinguish between groups with the number ratio 7 : 8. The ability to compare two quantities begins to develop after 15 months of age and children learn how to count spontaneously, together with the acquisition of language. Speech enables children to understand number in its abstract, symbolic sense, thus opening the way to symbolic arithmetic. During the preschool period children use intuition when doing calculations, but in school the arithmetic is based on the knowledge of arithmetical algorithms. So, in order to acquire mathematical knowledge, it is necessary to incorporate memory and automate arithmetical processes, without the use of intuition. However, research has shown that intuition is very important and is even a predictive factor for the development of mathematical abilities throughout the schooling process.

  3. Discourse abilities in the structure of intelligence

    Directory of Open Access Journals (Sweden)

    Voronin A. N.

    2017-09-01

    Full Text Available Background. This article is devoted to empirical research on discourse abilities within the structure of cognitive abilities. Discourse abilities, as well as linguistic abilities, are part of language abilities, but they are directly linked with discourse practices and a certain communicative situation. Discourse abilities allow a person to effectively initiate, keep, expand, and complete the process of communication, using language appropriate to any given situation. These abilities contribute to making communication more effective and achieving mutual understanding between partners, while at the same time they speed up the process of forming an interaction strategy. the empirical verification of the construct “discourse abilities,” and the design of original diagnostic tests on them, led us to differentiate linguistic and discourse abilities. Objective. However, it is not yet clear what place discourse abilities occupy in the structure of cognitive abilities. This is the primary goal of our research. Method. The design of the study involved group testing (in groups of 15-35 people using the following methods: a discourse abilities test; a short selection test; a social intelligence test, and short variations of Torrance’s and Mednick’s tests. In total, 208 people (133 women and 75 men, ages 17 to 21 years participated in the study, all of them either first year humanities students or high school students from Moscow. Results and Discussion. The research results revealed that discourse abilities relevantly correlate with the majority of indicators of general and social intelligence and creativity (except non-verbal intelligence. Discourse abilities as part of the structure of cognitive capabilities form a discrete factor, and include relevant components such as verbal and general intelligence and indicators of social intelligence, such as the ability to group expressions. Structures indicative of cognitive abilities varied within the

  4. Microstructure and magnetic properties of mechanically alloyed FeSiBAlNi (Nb) high entropy alloys

    Science.gov (United States)

    Wang, Jian; Zheng, Zhou; Xu, Jing; Wang, Yan

    2014-04-01

    In this paper, the effects of milling duration and composition on the microstructure and magnetic properties of equi-atomic FeSiBAlNi and FeSiBAlNiNb high entropy alloys during mechanical alloying have been investigated using X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy and alternating gradient magnetometry. The amorphous high entropy alloys have been successfully fabricated using the mechanical alloying method. The results show that the Nb addition prolongs the milling time for the formation of the fully FeSiBAlNi amorphous phase and decreases the glass forming ability. However, FeSiBAlNiNb amorphous high entropy alloy has the higher thermal stability and heat resisting properties. Moreover, the as-milled FeSiBAlNi(Nb) powders are soft-magnetic materials indicated by their low coercivity. The saturation magnetization of the as-milled FeSiBAlNi(Nb) powders decreases with prolonging of the milling time and shows the lowest value when the amorphous high entropy alloys are formed. It suggests that the as-milled products with solid solution phases show the better soft-magnetic properties than those with fully amorphous phases. The Nb addition does not improve the soft-magnetic properties of the FeSiBAlNi high entropy alloys. Rather, both amorphous high entropy alloys have similar soft-magnetic properties after a long milling time.

  5. Adaptive Behaviors in High-Functioning Taiwanese Children with Autism Spectrum Disorders: An Investigation of the Mediating Roles of Symptom Severity and Cognitive Ability

    Science.gov (United States)

    Chang, Chen-Lin; Lung, For-Wey; Yen, Cheng-Fang; Yang, Pinchen

    2013-01-01

    We investigated the relationship among cognitive level, autistic severity and adaptive function in a Taiwanese sample of 94 high-functioning children with autism spectrum disorders (ASD) (mean full scale intelligent quotients FSIQ = 84.8). Parents and teachers both completed the Adaptive Behavior Assessment System-II and the Social Responsiveness…

  6. Priming Ability Emotional Intelligence

    Science.gov (United States)

    Schutte, Nicola S.; Malouff, John M.

    2012-01-01

    Two studies examined whether priming self-schemas relating to successful emotional competency results in better emotional intelligence performance. In the first study participants were randomly assigned to a successful emotional competency self-schema prime condition or a control condition and then completed an ability measure of emotional…

  7. Synchronization of Mental Abilities

    NARCIS (Netherlands)

    Guney, A.

    2008-01-01

    I think it is better to summarize some cognitive issues in relation to this subject; how we learn, how we should organize learning (instructions), knowledge, etc. before treating creativity and rationality. Is it, really, possible to consider creativity without any kind of involvement of the ability

  8. La Inteligencia Social: Aportes Desde su Estudio en Niños y Adolescente con Altas Capacidades Cognitivas Social Intelligence: Contributions From its Study in Children and Adolescents With High Cognitive Abilities

    Directory of Open Access Journals (Sweden)

    Verónica López

    2007-11-01

    Full Text Available El constructo de "inteligencia social" ha suscitado reiterados cuestionamientos a lo largo de la historia de la Psicología. Una forma de contribuir al debate es a través del estudio del razonamiento social en personas con altas capacidades cognitivas. Las puntuaciones de 50 niños y adolescentes con altas capacidades cognitivas en dos medidas de razonamiento social fueron comparadas con las de un grupo de pares de capacidad cognitiva media equiparados uno a uno en sexo y edad cronológica. Los resultados indican que estos niños y adolescentes presentan un rendimiento significativamente superior a sus pares en tareas relacionadas con la inteligencia social, destacando sobre todo en procesos de razonamiento que involucran la comprensión y definición del problema social, la planificación de estrategias y la anticipación de consecuencias sociales.The construct of "social intelligence" has aroused reiterated debates throughout the history of Psychology. One way to contribute to this debate is through the study of social reasoning in people with high cognitive abilities. The scores of 50 Spanish-speaking children and adolescents with high cognitive abilities in two measures of social reasoning were compared to age- and sex-matched peers of normotypical cognitive ability. The results indicate that high-ability children and adolescents present a significatively superior performance compared to their peers in tasks related with social intelligence, especially in reasoning processes which involve understanding and defining the social problem, planning social strategies and anticipating social consequences.

  9. Development of Reasoning Test Instruments Based on TIMSS Framework for Measuring Reasoning Ability of Senior High School Student on the Physics Concept

    Science.gov (United States)

    Muslim; Suhandi, A.; Nugraha, M. G.

    2017-02-01

    The purposes of this study are to determine the quality of reasoning test instruments that follow the framework of Trends in International Mathematics and Science Study (TIMSS) as a development results and to analyse the profile of reasoning skill of senior high school students on physics materials. This research used research and development method (R&D), furthermore the subject were 104 students at three senior high schools in Bandung selected by random sampling technique. Reasoning test instruments are constructed following the TIMSS framework in multiple choice forms in 30 questions that cover five subject matters i.e. parabolic motion and circular motion, Newton’s law of gravity, work and energy, harmonic oscillation, as well as the momentum and impulse. The quality of reasoning tests were analysed using the Content Validity Ratio (CVR) and classic test analysis include the validity of item, level of difficulty, discriminating power, reliability and Ferguson’s delta. As for the students’ reasoning skills profiles were analysed by the average score of achievements on eight aspects of the reasoning TIMSS framework. The results showed that reasoning test have a good quality as instruments to measure reasoning skills of senior high school students on five matters physics which developed and able to explore the reasoning of students on all aspects of reasoning based on TIMSS framework.

  10. Methods of vitrifying waste with low melting high lithia glass compositions

    Science.gov (United States)

    Jantzen, Carol M.; Pickett, John B.; Cicero-Herman, Connie A.; Marra, James C.

    2001-01-01

    The invention relates to methods of vitrifying waste and for lowering the melting point of glass forming systems by including lithia formers in the glass forming composition in significant amounts, typically from about 0.16 wt % to about 11 wt %, based on the total glass forming oxides. The lithia is typically included as a replacement for alkali oxide glass formers that would normally be present in a particular glass forming system. Replacement can occur on a mole percent or weight percent basis, and typically results in a composition wherein lithia forms about 10 wt % to about 100 wt % of the alkali oxide glass formers present in the composition. The present invention also relates to the high lithia glass compositions formed by these methods. The invention is useful for stabilization of numerous types of waste materials, including aqueous waste streams, sludge solids, mixtures of aqueous supernate and sludge solids, combinations of spent filter aids from waste water treatment and waste sludges, supernate alone, incinerator ash, incinerator offgas blowdown, or combinations thereof, geological mine tailings and sludges, asbestos, inorganic filter media, cement waste forms in need of remediation, spent or partially spent ion exchange resins or zeolites, contaminated soils, lead paint, etc. The decrease in melting point achieved by the present invention desirably prevents volatilization of hazardous or radioactive species during vitrification.

  11. Cognitive Correlates of Different Mentalizing Abilities in Individuals with High and Low Trait Schizotypy: Findings from an Extreme-Group Design

    Directory of Open Access Journals (Sweden)

    Krisztina Kocsis-Bogár

    2017-06-01

    Full Text Available Mentalizing or Theory of Mind (ToM deficits in schizophrenia have been studied to great extent, but studies involving samples of trait schizotypy yield ambiguous results. Executive functions like cognitive inhibition, cognitive flexibility, and agency are all prerequisites of mentalizing, and it is assumed that the impairment of these functions contributes to ToM deficits in schizophrenia. Whether these impairments influence the ToM performance of people with high trait schizotypy remains unclear. Although impaired self-agency has repeatedly been identified in people with schizotypy, its role in mentalizing is yet to be investigated. The main aim of this study was to explore whether deficits in cognitive and affective ToM can be found in high trait schizotypy, and to identify in what way these deficits are related to the positive and negative dimensions of schizotypy. The secondary aim was to examine whether these deficits correlate with executive functions. Based on the dimensional view of the schizophrenia spectrum, an extreme-group design was applied to non-clinical volunteers demonstrating high (N = 39 and low (N = 47 trait schizotypy. Affective and cognitive ToM were investigated using the Movie for Assessment of Social Cognition, a sensitive and video-based measurement. Cognitive inhibition was assessed using the Stroop Test, and cognitive flexibility was analyzed using the Trail-Making Test. Agency was measured using a computerized self-agency paradigm. Participants in the high-schizotypy group performed significantly worse in the affective ToM task (d = 0.79, and their overall ToM performance was significantly impaired (d = 0.60. No between-group differences were found with regards to cognitive ToM, executive functions, and self-agency. Cognitive flexibility correlated negatively with positive schizotypy, and contributed to a worse overall and affective ToM. Impaired cognitive inhibition contributed to undermentalizing-type errors. It

  12. Term Amniotic membrane is a high throughput source for multipotent Mesenchymal Stem Cells with the ability to differentiate into endothelial cells in vitro

    DEFF Research Database (Denmark)

    Alviano, Francesco; Fossati, Valentina; Marchionni, Cosetta

    2007-01-01

    BACKGROUND: Term Amniotic membrane (AM) is a very attractive source of Mesenchymal Stem Cells (MSCs) due to the fact that this fetal tissue is usually discarded without ethical conflicts, leading to high efficiency in MSC recovery with no intrusive procedures. Here we confirmed that term AM...... profile, i.e., positive for CD105, CD73, CD29, CD44, CD166 and negative for CD14, CD34, CD45, consistent with that reported for bone marrow-derived MSCs. In addition, amniotic membrane-isolated cells underwent in vitro osteogenic (von Kossa stain), adipogenic (Oil Red-O stain), chondrogenic (collagen type...

  13. Why Some Countries Attract More High-Ability Young Students to Teaching: Cross-National Comparisons of Students’ Expectation of Becoming a Teacher

    Science.gov (United States)

    PARK, HYUNJOON; BYUN, SOO-YONG

    2017-01-01

    Using data from 37,570 students in 23 OECD countries in PISA 2006, we examine how national contexts shape the expectation of being a teacher at age 30 among high-achieving students in secondary schools. Our results show considerable between-country differences in the degree of students’ expectation of a teaching job. To address sources of this cross-national variation, we use two-level logit models by linking student-level data with country-level data. Consistent with earlier findings, we find that teachers’ economic status matters for students’ expectation of becoming a teacher. Moreover, our results show that teachers’ social status also matters. Countries’ levels of professionalization of teaching, indicated by whether teachers have a bachelor’s degree and are fully certified, are also related to students’ expectation of the teaching profession. Specifically, in countries with higher levels of professionalization, we see a reduced gender gap in students’ expectation of becoming a teacher. PMID:28529349

  14. An eye-tracking method to reveal the link between gazing patterns and pragmatic abilities in high functioning autism spectrum disorders

    Directory of Open Access Journals (Sweden)

    Ouriel eGrynszpan

    2015-01-01

    Full Text Available The present study illustrates the potential advantages of an eye-tracking method for exploring the association between visual scanning of faces and inferences of mental states. Participants watched short videos involving social interactions and had to explain what they had seen. The number of cognition verbs (e.g. think, believe, know in their answers were counted. Given the possible use of peripheral vision that could confound eye-tracking measures, we added a condition using a gaze-contingent viewing window: the entire visual display is blurred, expect for an area that moves with the participant’s gaze. Eleven typical adults and eleven high functioning adults with ASD were recruited. The condition employing the viewing window yielded strong correlations between the average duration of fixations, the ratio of cognition verbs and standard measures of social disabilities.

  15. Music and nonmusical abilities.

    Science.gov (United States)

    Schellenberg, E G

    2001-06-01

    Reports that exposure to music causes benefits in nonmusical domains have received widespread attention in the mainstream media. Such reports have also influenced public policy. The so-called "Mozart effect" actually refers to two relatively distinct phenomena. One concerns short-term increases in spatial abilities that are said to occur from listening to music composed by Mozart. The other refers to the possibility that formal training in music yields nonmusical benefits. A review of the relevant findings indicates that the short-term effect is small and unreliable. Moreover, when it is evident, it can be explained by between-condition differences in the listener's mood or levels of cognitive arousal. By contrast, the effect of music lessons on nonmusical aspects of cognitive development is still an open question. Several studies have reported positive associations between formal music lessons and abilities in nonmusical (e.g., linguistic, mathematical, and spatial) domains. Nonetheless, compelling evidence for a causal link remains elusive.

  16. High Resolution Definition of Subsurface Heterogeneity for Understanding the Biodynamics of Natural Field Systems: Advancing the Ability for Scaling to Field Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Majer, Ernest L.; Brockman, Fred J.

    1999-12-31

    This research is an integrated project which uses physical (geophysical and hydrologic) and innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect bioremediation. In the this effort data from controlled laboratory and in situ experiments at the Idaho National Engineering and Environmental (INEEL) Test Area North (TAN) site were used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in situ and correlated with flow and transport properties. Emphasis was placed on identifying fundamental scales of variation of physical parameters that control transport behavior relative to subsurface microbial dynamics that could be used to develop a predictive model. A key hypothesis of the work was that nutrient flux and transport properties are key factors in controlling microbial dynamics, and that geophysical techniques could be used to identify the critical physical properties and scales controlling transport. This hypothesis was essentially validated. The goal was not only to develop and apply methods to monitor the spatial and temporal distribution of the bioremediation in fractured sites such as TAN, but also to develop methods applicable to a wider range of DOE sites. The outcome has been an improved understanding of the relationship between physical, chemical and microbial processes in heterogeneous environments, thus applicable to the design and monitoring of bioremediation strategies for a variety of environments. In this EMSP work we demonstrated that high resolution geophysical methods have considerable resolving power, especially when linked with modern advanced processing and interpretation. In terms of basic science, in addition to providing innovative methods for monitoring bioremediation, the work also provided a strong motivation for developing and extending high resolution geophysical methods.

  17. A sportomics strategy to analyze the ability of arginine to modulate both ammonia and lymphocyte levels in blood after high-intensity exercise

    Directory of Open Access Journals (Sweden)

    Gonçalves Luis

    2012-06-01

    Full Text Available Abstract Background Exercise is an excellent tool to study the interactions between metabolic stress and the immune system. Specifically, high-intensity exercises both produce transient hyperammonemia and influence the distribution of white blood cells. Carbohydrates and glutamine and arginine supplementation were previously shown to effectively modulate ammonia levels during exercise. In this study, we used a short-duration, high-intensity exercise together with a low carbohydrate diet to induce a hyperammonemia state and better understand how arginine influences both ammonemia and the distribution of leukocytes in the blood. Methods Brazilian Jiu-Jitsu practitioners (men, n = 39 volunteered for this study. The subjects followed a low-carbohydrate diet for four days before the trials and received either arginine supplementation (100 mg·kg-1 of body mass·day-1 or a placebo. The intergroup statistical significance was calculated by a one-way analysis of variance, followed by Student’s t-test. The data correlations were calculated using Pearson’s test. Results In the control group, ammonemia increased during matches at almost twice the rate of the arginine group (25 mmol·L-1·min-1 and 13 μmol·L-1·min-1, respectively. Exercise induced an increase in leukocytes of approximately 75%. An even greater difference was observed in the lymphocyte count, which increased 2.2-fold in the control group; this increase was partially prevented by arginine supplementation. The shape of the ammonemia curve suggests that arginine helps prevent increases in ammonia levels. Conclusions These data indicate that increases in lymphocytes and ammonia are simultaneously reduced by arginine supplementation. We propose that increased serum lymphocytes could be related to changes in ammonemia and ammonia metabolism.

  18. Hypolipidemic effect and protection ability of liver-kidney functions of melanin from Lachnum YM226 in high-fat diet fed mice.

    Science.gov (United States)

    Shi, Fang; Li, Jinglei; Yang, Liuqing; Hou, Guohua; Ye, Ming

    2018-02-21

    In the present study, we investigated the hypolipidemic properties of melanin from Lachnum YM226 (LM) in high-fat diet induced hyperlipidemic mice. After the hyperlipidemic model was established, mice were randomly divided into six groups, as follows: normal control group (NC), hyperlipidemic control group (HC), positive control group (7 mg kg -1 d -1 simvastatin) (PC) and LM groups (50, 100 and 200 mg kg -1 d -1 denoted as LM-50, LM-100 and LM-200, respectively). Subsequently, the body weight, organ indices, lipid metabolism, antioxidant properties and liver-kidney functions of the mice were examined. Moreover, the activities of lipoprotein metabolism enzymes in serum and liver tissue were examined to study the feasible mechanism. The results imply that LM could effectively reduce body weight, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and atherogenic index (AI), and increase high density lipoprotein cholesterol (HDL-C). Moreover, treatment with LM also increased the antioxidant enzymes activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) and reduced malondialdehyde (MDA) content relative to the HC group. In addition, the liver and kidney damage indices such as alanine aminotransferase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), creatinine (CRE), blood urea nitrogen (BUN) and uric acid were lowered. LM administration also significantly corrected disturbances of liver-kidney functions with no fatty deposits in the liver, resulting in a protective effect against renal histological alteration. The hypolipidemic effect occurred partly due to the regulation of hepatic lipase (HL) and lipoprotein lipase (LPL) in serum and liver to markedly decrease TG. This confirms the important role of LM in the prevention of hyperlipidemia.

  19. Term amniotic membrane is a high throughput source for multipotent mesenchymal stem cells with the ability to differentiate into endothelial cells in vitro

    Directory of Open Access Journals (Sweden)

    Pasquinelli Gianandrea

    2007-02-01

    Full Text Available Abstract Background Term Amniotic membrane (AM is a very attractive source of Mesenchymal Stem Cells (MSCs due to the fact that this fetal tissue is usually discarded without ethical conflicts, leading to high efficiency in MSC recovery with no intrusive procedures. Here we confirmed that term AM, as previously reported in the literature, is an abundant source of hMSCs; in particular we further investigated the AM differentiation potential by assessing whether these cells may also be committed to the angiogenic fate. In agreement with the recommendation of the International Society for Cellular Therapy, the mesenchymal cells herein investigated were named Amniotic Membrane-human Mesenchymal Stromal Cells (AM-hMSC. Results The recovery of hMSCs and their in vitro expansion potential were greater in amniotic membrane than in bone marrow stroma. At flow cytometry analysis AM-hMSCs showed an immunophenotypical profile, i.e., positive for CD105, CD73, CD29, CD44, CD166 and negative for CD14, CD34, CD45, consistent with that reported for bone marrow-derived MSCs. In addition, amniotic membrane-isolated cells underwent in vitro osteogenic (von Kossa stain, adipogenic (Oil Red-O stain, chondrogenic (collagen type II immunohistochemichal detection and myogenic (RT-PCR MyoD and Myogenin expression as well as desmin immunohistochemical detection differentiation. In angiogenic experiments, a spontaneous differentiation into endothelial cells was detected by in vitro matrigel assay and this behaviour has been enhanced through Vascular Endothelial Growth Factor (VEGF induction. According to these findings, VEGF receptor 1 and 2 (FLT-1 and KDR were basally expressed in AM-hMSCs and the expression of endothelial-specific markers like FLT-1 KDR, ICAM-1 increased after exposure to VEGF together with the occurrence of CD34 and von Willebrand Factor positive cells. Conclusion The current study suggests that AM-hMSCs may emerge as a remarkable tool for the cell

  20. Entrepreneurial Intention and Entrepreneurial Abilities | Jayeoba ...

    African Journals Online (AJOL)

    The study is an important indication of the role of and correlation between ability and intentions. It will be of practical benefit to conduct a follow-up/longitudinal study on future work preferences of the undergraduates who score high in entrepreneurial abilities scale as well as those who has entrepreneurial intention.

  1. Some effects of ability grouping in Harare secondary schools: a case ...

    African Journals Online (AJOL)

    Erna Kinsey

    that ability grouping places low ability learners at a disadvantage, and encourages social stratification among learners of different abilities. (Oakes, 1982 ..... benefits both high ability and low ability learners, the findings of this research pointed to the fact that neither the high ability learners nor the low ability learners ...

  2. General English Ability, Specific Purpose English Ability, and Computer Skills.

    Science.gov (United States)

    Prapphal, Kanchana

    2003-01-01

    Aims to answer the following research questions: (1) Are general English ability and specific purpose English ability related to computer skills? and (2) Is general English ability transferable to specific purpose English ability? Subjects were third year science students enrolled in an English for academic purposes course. (Author/VWL)

  3. Quench-in of different high T complexities of glassformers for leisurely study at lower temperatures

    DEFF Research Database (Denmark)

    Angell, C. A.; Yue, Yuanzheng; Wang, L. M.

    Quenching-in of different high T complexities of glassformers for leisurely study at lower temperatures We describe a series of experiments on glass-forming liquids that are motivated by a common idea. The idea is that of trapping in a high enthalpy, high entropy, and state of the system by quenc......Quenching-in of different high T complexities of glassformers for leisurely study at lower temperatures We describe a series of experiments on glass-forming liquids that are motivated by a common idea. The idea is that of trapping in a high enthalpy, high entropy, and state of the system...... by quenching to the glassy state at extreme rates, and then observing the way the system evolves at low temperatures during a controlled annealing procedure. In this manner, events that normally occur during change of temperature may be observed occurring during passage of time, at much lower temperatures...

  4. Varieties of numerical abilities.

    Science.gov (United States)

    Dehaene, S

    1992-08-01

    This paper provides a tutorial introduction to numerical cognition, with a review of essential findings and current points of debate. A tacit hypothesis in cognitive arithmetic is that numerical abilities derive from human linguistic competence. One aim of this special issue is to confront this hypothesis with current knowledge of number representations in animals, infants, normal and gifted adults, and brain-lesioned patients. First, the historical evolution of number notations is presented, together with the mental processes for calculating and transcoding from one notation to another. While these domains are well described by formal symbol-processing models, this paper argues that such is not the case for two other domains of numerical competence: quantification and approximation. The evidence for counting, subitizing and numerosity estimation in infants, children, adults and animals is critically examined. Data are also presented which suggest a specialization for processing approximate numerical quantities in animals and humans. A synthesis of these findings is proposed in the form of a triple-code model, which assumes that numbers are mentally manipulated in an arabic, verbal or analogical magnitude code depending on the requested mental operation. Only the analogical magnitude representation seems available to animals and preverbal infants.

  5. Virtual, on-line, frog dissection vs. conventional laboratory dissection: A comparison of student achievement and teacher perceptions among honors, general ability, and foundations-level high school biology classes

    Science.gov (United States)

    Kopec, Ronald H.

    2002-09-01

    Dissecting animal specimens has long been a tradition in biology classes. Objections by students, based on religious or ethical grounds, have been raised regarding the dissections of animals in classroom laboratories. A number of states now have legal proceedings or statewide policies requiring that alternatives to the actual dissection of laboratory animal specimens be permitted in their school districts. Alternatives to actual dissections have been developed in recent years. For a variety of reasons, performing an actual or conventional animal dissection may not be a desirable option. The purpose of this study was to investigate how a virtual On-line frog dissection compares with an actual laboratory dissection. What were the perceptions of the teacher's using it? How does student achievement compare among three the different ability levels on a pre and posttest regarding basic frog anatomy? Is a virtual On-line dissection a suitable alternative for students who, for whatever reason, do not participate in the actual laboratory experience? The subjects consisted of 218 biology students among three different ability levels, in a Northeastern suburban high school. Approximately half of the student groups participated in a virtual On-line dissection, the other half in an actual laboratory dissection. A pretest of basic frog anatomy was administered to the students two days before and the posttest one day after their dissection experience. Data were analyzed using matched pairs t-Tests, Analysis of Variance, Tukey HSD, and Squared Curvilinear Coefficients. Survey questionnaires were administered to the teachers after the dissection experiences were completed. There were no significant differences found in achievement between the virtual and conventional dissection groups. There were significant differences found in achievement score means among the three ability levels. There was no significant interaction between gender and achievement. Perceptions of the teacher

  6. Crystallization behavior and magnetic properties in High Fe content FeBCSiCu alloy system

    Science.gov (United States)

    Fan, X. D.; Shen, B. L.

    2015-07-01

    High Fe content FeBCSiCu nanocrystalline alloys are prepared by annealing melt-spun amorphous ribbons with aim at increasing saturation magnetic flux density. Microstructures identified by XRD and TEM reveal that Cu addition inhibits the surface crystallization of Fe86B7C7 alloy and improve its glass-forming ability. Activation energy of crystallization calculated by Kissinger's equation indicates that both Cu and Si addition promotes the precipitation of α-Fe phase and improves the thermal stability. VSM and DC B-H loop tracer measurements show that the Fe85.5B7C6Si1Cu0.5 nanocrystalline alloy exhibits high saturation magnetic flux density of 1.8 T and low coercivity of 10 A/m, respectively. AC properties measured by AC B-H analyzer show this alloy exhibits low core loss of 0.35 W/kg at 1 T at 50 Hz. Low material cost and convenient productivity make the Fe85.5B7C6Si1Cu0.5 nanocrystalline alloy an economical application in industry.

  7. Control coordination abilities in shock combat sports

    Directory of Open Access Journals (Sweden)

    Natalya Boychenko

    2014-12-01

    Full Text Available Purpose: optimize the process control level of coordination abilities in martial arts. Material and Methods: analysis and compilation of scientific and methodological literature, interviews with coaches of drum martial arts, video analysis techniques, teacher observations. Results: identified specific types of coordination abilities in shock combat sports. Pod branny and offered specific and nonspecific tests to monitor the level of species athletes coordination abilities. Conclusion: it is determined that in order to achieve victory in the fight martial artists to navigate the space to be able to assess and manage dynamic and spatio-temporal parameters of movements, maintain balance, have a high coordination of movements. The proposed tests to monitor species coordination abilities athletes allow an objective assessment of not only the overall level of coordination, and the level of specific types of manifestations of this ability.

  8. Parkinson's disease and driving ability.

    Science.gov (United States)

    Singh, Rajiv; Pentland, Brian; Hunter, John; Provan, Frances

    2007-04-01

    To explore the driving problems associated with Parkinson's disease (PD) and to ascertain whether any clinical features or tests predict driver safety. The driving ability of 154 individuals with PD referred to a driving assessment centre was determined by a combination of clinical tests, reaction times on a test rig and an in-car driving test. The majority of cases (104, 66%) were able to continue driving although 46 individuals required an automatic transmission and 10 others needed car modifications. Ability to drive was predicted by the severity of physical disease, age, presence of other associated medical conditions, particularly dementia, duration of disease, brake reaction, time on a test rig and score on a driving test (all pdriving history were not correlated. Discriminant analysis revealed that the most important features in distinguishing safety to drive were severe physical disease (Hoehn and Yahr stage 3), reaction time, moderate disease associated with another medical condition and high score on car testing. Most individuals with PD are safe to drive, although many benefit from car modifications or from using an automatic transmission. A combination of clinical tests and in-car driving assessment will establish safety to drive, and a number of clinical correlates can be shown to predict the likely outcome and may assist in the decision process. This is the largest series of consecutive patients seen at a driving assessment centre reported to date, and the first to devise a scoring system for on-road driving assessment.

  9. Managerial Ability Of Headmasters At Sinjai District

    Directory of Open Access Journals (Sweden)

    Madalle Agi

    2017-02-01

    Full Text Available This study aims to determine 1 a description of planning capability on the effectiveness of performance 2 a description of the ability to organize on performance 3 a description of the ability of leadership on the effectiveness of performance 4 a description of the ability of socio-emotional on the effectiveness of performance 5 a description of ability to supervise the performance effectiveness 6 the effect of capability planning organizing leadership socio-emotional simultaneous monitoring of the effectiveness of the performance. The method used is survey explanatory aimed to test the hypothesis by using the sampling method. Sampling was conducted through stratified random sampling technique. The data collection was done by using documentation and technical questionnaires. This study uses a combination of quantitative methods that dominant ie supported by qualitative methods. Quantitative data were analyzed with path analysis were processed using SPSS software while the qualitative data collected through documents and questionnaires then reduced and served. Research shows that the ability to plan does not affect the effectiveness of school performance because the programming is still normative and not yet fully involve stakeholders the ability to organize significantly influence the effectiveness categorized quite good performance leadership ability significantly influence the effectiveness of performance in both categories the ability of socio- emotional significantly influence the effectiveness of the performance in good enough category surveillance capabilities significantly influence the effectiveness of the performance of the category is quite good and the ability of planning organizing leadership socio-emotional monitoring positive and significant impact on the effectiveness of the performance of the very high category. Interesting things were found from the results of research in Sinjai is very dominant leadership abilities affect the

  10. Cognitive abilities of musicians.

    Science.gov (United States)

    Giovagnoli, A R; Raglio, A

    2011-10-01

    Playing music may involve different cognitive domains, but previous studies of musicians and patients with brain lesions have reported inconsistent associations between music performances and other cognitive functions. Fine musical performance may be associated with high executive and control functions. 21 skilled musicians and 21 age- and education-matched healthy controls with no specific musical competence were compared on attentive, executive, linguistic, perceptual, praxic, memory, and theory of mind functions, using standardized neuropsychological tests. No differences between the musicians and controls, music composers and performers, or between soloists or orchestral players were observed. In musicians, there was no correlation between the test scores and amount of music education. Findings based on these musician groups, carefully evaluated, suggest further exploration of associations of distinct components of music comprehension and expression with different cognitive functions and behavioral aspects.

  11. Historical Evolution of Spatial Abilities

    Directory of Open Access Journals (Sweden)

    A. Ardila

    1993-01-01

    Full Text Available Historical evolution and cross-cultural differences in spatial abilities are analyzed. Spatial abilities have been found to be significantly associated with the complexity of geographical conditions and survival demands. Although impaired spatial cognition is found in cases of, exclusively or predominantly, right hemisphere pathology, it is proposed that this asymmetry may depend on the degree of training in spatial abilities. It is further proposed that spatial cognition might have evolved in a parallel way with cultural evolution and environmental demands. Contemporary city humans might be using spatial abilities in some new, conceptual tasks that did not exist in prehistoric times: mathematics, reading, writing, mechanics, music, etc. Cross-cultural analysis of spatial abilities in different human groups, normalization of neuropsychological testing instruments, and clinical observations of spatial ability disturbances in people with different cultural backgrounds and various spatial requirements, are required to construct a neuropsychological theory of brain organization of spatial cognition.

  12. Language mastery, narrative abilities and oral expression abilities in ...

    African Journals Online (AJOL)

    The importance of language and language mastery for science learning has been the object of extensive investigation in recent decades, leading to ample recognition. However, specific focus on the role of narrative abilities is still scarce. This work focuses on the relevance of narrative abilities for chemistry learning.

  13. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances. We ensured exogenous...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub-teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  14. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances for one year. We ensured...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub-teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  15. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 (student) teams start up and manage real companies under identical circumstances for one year. We...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub- teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  16. Vocabulary abilities of children with Williams syndrome: strengths, weaknesses, and relation to visuospatial construction ability.

    Science.gov (United States)

    Mervis, Carolyn B; John, Angela E

    2008-08-01

    This project was designed to identify relative strengths and weaknesses in vocabulary ability for children with Williams syndrome (WS) and to demonstrate the importance of stringent matching criteria for cross-group comparisons. Children with WS and typically developing (TD) children completed standardized assessments of intellectual and language ability. Children with WS also completed a visuospatial construction ability assessment. Study 1: Concrete and relational vocabulary standard scores were significantly lower for 5- to 7-year-olds with WS than for TD children. Children with WS earned significantly higher standard scores for concrete than for relational vocabulary. When groups were stringently matched for relational vocabulary size, children with WS did not evidence a specific weakness in spatial vocabulary. Study 2: Standard scores for relational vocabulary were similar to those for visuospatial construction ability for 5- to 7-year-olds with WS. Study 3: Nine- to 11-year-olds with WS demonstrated very limited relational vocabulary ability; relational vocabulary ability at 5-7 years was highly correlated with later relational language ability. Concrete vocabulary is a relative strength for children with WS; relational vocabulary ability is very limited and is at about the level of visuospatial construction ability. Accurate determination of group comparison results depends on stringent group matching.

  17. Vocabulary Abilities of Children with Williams Syndrome: Strengths, Weaknesses, and Relation to Visuospatial Construction Ability

    Science.gov (United States)

    Mervis, Carolyn B.; John, Angela E.

    2008-01-01

    Purpose This project was designed to identify relative strengths and weaknesses in vocabulary ability for children with Williams syndrome (WS) and to demonstrate the importance of stringent matching criteria for cross-group comparisons. Methods Children with WS and typically developing (TD) children completed standardized assessments of intellectual and language ability. Children with WS also completed a visuospatial construction ability assessment. Results Study 1: Concrete and relational vocabulary standard scores were significantly lower for 5 – 7-year-olds with WS than for TD children. Children with WS earned significantly higher standard scores for concrete than for relational vocabulary. When groups were stringently matched for relational vocabulary size, children with WS did not evidence a specific weakness in spatial vocabulary. Study 2: Standard scores for relational vocabulary were similar to those for visuospatial construction ability for 5 – 7-year-olds with WS. Study 3: 9 – 11-year-olds with WS demonstrated very limited relational vocabulary ability; relational vocabulary ability at 5 – 7 years was highly correlated with later relational language ability. Conclusions Concrete vocabulary is a relative strength for children with WS; relational vocabulary ability is very limited and is at about the level of visuospatial construction ability. Accurate determination of group comparison results depends on stringent group matching. PMID:18658065

  18. High-temperature calcined fullerene nanowhiskers as well as long needle-like multi-wall carbon nanotubes have abilities to induce NLRP3-mediated IL-1β secretion.

    Science.gov (United States)

    Cui, Hongyan; Wu, Weijia; Okuhira, Keiichiro; Miyazawa, Kun'ichi; Hattori, Takayuki; Sai, Kimie; Naito, Mikihiko; Suzuki, Kazuhiro; Nishimura, Tetsuji; Sakamoto, Yoshimitsu; Ogata, Akio; Maeno, Tomokazu; Inomata, Akiko; Nakae, Dai; Hirose, Akihiko; Nishimaki-Mogami, Tomoko

    2014-09-26

    Because multi-wall carbon nanotubes (MWCNTs) have asbestos-like shape and size, concerns about their pathogenicity have been raised. Contaminated metals of MWCNTs may also be responsible for their toxicity. In this study, we employed high-temperature calcined fullerene nanowhiskers (HTCFNWs), which are needle-like nanofibers composed of amorphous carbon having similar sizes to MWCNTs but neither metal impurities nor tubular structures, and investigated their ability to induce production a major proinflammatory cytokine IL-1β via the Nod-like receptor pyrin domain containing 3 (NLRP3)-containing flammasome-mediated mechanism. When exposed to THP-1 macrophages, long-HTCFNW exhibited robust IL-1β production as long and needle-like MWCNTs did, but short-HTCFNW caused very small effect. IL-1β release induced by long-HTCFNW as well as by long, needle-like MWCNTs was abolished by a caspase-1 inhibitor or siRNA-knockdown of NLRP3, indicating that NLRP3-inflammasome-mediated IL-1β production by these carbon nanofibers. Our findings indicate that the needle-like shape and length, but neither metal impurities nor tubular structures of MWCNTs were critical to robust NLRP3 activation. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. A Preliminary Study of the Ability of the 4Kscore test, the Prostate Cancer Prevention Trial-Risk Calculator and the European Research Screening Prostate-Risk Calculator for Predicting High-Grade Prostate Cancer.

    Science.gov (United States)

    Borque-Fernando, Á; Esteban-Escaño, L M; Rubio-Briones, J; Lou-Mercadé, A C; García-Ruiz, R; Tejero-Sánchez, A; Muñoz-Rivero, M V; Cabañuz-Plo, T; Alfaro-Torres, J; Marquina-Ibáñez, I M; Hakim-Alonso, S; Mejía-Urbáez, E; Gil-Fabra, J; Gil-Martínez, P; Ávarez-Alegret, R; Sanz, G; Gil-Sanz, M J

    2016-04-01

    To prevent the overdiagnosis and overtreatment of prostate cancer (PC), therapeutic strategies have been established such as active surveillance and focal therapy, as well as methods for clarifying the diagnosis of high-grade prostate cancer (HGPC) (defined as a Gleason score ≥7), such as multiparametric magnetic resonance imaging and new markers such as the 4Kscore test (4KsT). By means of a pilot study, we aim to test the ability of the 4KsT to identify HGPC in prostate biopsies (Bx) and compare the test with other multivariate prognostic models such as the Prostate Cancer Prevention Trial Risk Calculator 2.0 (PCPTRC 2.0) and the European Research Screening Prostate Cancer Risk Calculator 4 (ERSPC-RC 4). Fifty-one patients underwent a prostate Bx according to standard clinical practice, with a minimum of 10 cores. The diagnosis of HGPC was agreed upon by 4 uropathologists. We compared the predictions from the various models by using the Mann-Whitney U test, area under the ROC curve (AUC) (DeLong test), probability density function (PDF), box plots and clinical utility curves. Forty-three percent of the patients had PC, and 23.5% had HGPC. The medians of probability for the 4KsT, PCPTRC 2.0 and ERSPC-RC 4 were significantly different between the patients with HGPC and those without HGPC (p≤.022) and were more differentiated in the case of 4KsT (51.5% for HGPC [25-75 percentile: 25-80.5%] vs. 16% [P 25-75: 8-26.5%] for non-HGPC; p=.002). All models presented AUCs above 0.7, with no significant differences between any of them and 4KsT (p≥.20). The PDF and box plots showed good discriminative ability, especially in the ERSPC-RC 4 and 4KsT models. The utility curves showed how a cutoff of 9% for 4KsT identified all cases of HGPC and provided a 22% savings in biopsies, which is similar to what occurs with the ERSPC-RC 4 models and a cutoff of 3%. The assessed predictive models offer good discriminative ability for HGPCs in Bx. The 4KsT is a good classification

  20. A Combinatorial Approach to the Investigation of Metal Systems that Form Both Bulk Metallic Glasses and High Entropy Alloys

    Science.gov (United States)

    Welk, Brian A.; Gibson, Mark A.; Fraser, Hamish L.

    2016-03-01

    In this work, compositionally graded specimens were deposited using the laser engineered net-shaping (LENS™) additive manufacturing technique to study the glass-forming ability of two bulk metallic glass (BMG) and high entropy alloy (HEA) composite systems. The first graded specimen varied from Zr57Ti5Al10Cu20Ni8 (BMG) to CoCrFeNiCu0.5 (HEA) and the second graded specimen varied from TiZrCuNb (BMG) to (TiZrCuNb)65Ni35 (HEA). After deposition, laser surface melting experiments were performed parallel to the gradient to remelt and rapidly solidify the specimen. Scanning electron microscopy and energy dispersive x-ray spectroscopy were used to determine the morphology and composition variations in the as-deposited and laser surface melted phases. Selected area diffraction of the melt pool regions confirmed an almost fully amorphous region in the first gradient and an amorphous matrix/crystalline dendrite composite structure in the second gradient.

  1. Narrative Abilities of Children with Epilepsy

    Science.gov (United States)

    Strekas, Amy; Ratner, Nan Bernstein; Berl, Madison; Gaillard, William D.

    2013-01-01

    Background: There is a noticeable publication gap in the speech-language pathology literature regarding the language abilities of children with common types of epilepsy. This paper reviews studies that suggest a high frequency of undetected language problems in this population, and it proposes the need for pragmatically based assessment of…

  2. Host country language ability and expatriate adjustment

    DEFF Research Database (Denmark)

    Selmer, Jan; Lauring, Jakob

    2015-01-01

    countries, one with an easy, relatively simple language and the other with a difficult, highly complex language. Consistent with Goal-Setting Theory, results indicated a relative advantage of expatriates’ language ability in terms of their adjustment in the host country with the difficult language...

  3. Balance ability and athletic performance.

    Science.gov (United States)

    Hrysomallis, Con

    2011-03-01

    The relationship between balance ability and sport injury risk has been established in many cases, but the relationship between balance ability and athletic performance is less clear. This review compares the balance ability of athletes from different sports, determines if there is a difference in balance ability of athletes at different levels of competition within the same sport, determines the relationship of balance ability with performance measures and examines the influence of balance training on sport performance or motor skills. Based on the available data from cross-sectional studies, gymnasts tended to have the best balance ability, followed by soccer players, swimmers, active control subjects and then basketball players. Surprisingly, no studies were found that compared the balance ability of rifle shooters with other athletes. There were some sports, such as rifle shooting, soccer and golf, where elite athletes were found to have superior balance ability compared with their less proficient counterparts, but this was not found to be the case for alpine skiing, surfing and judo. Balance ability was shown to be significantly related to rifle shooting accuracy, archery shooting accuracy, ice hockey maximum skating speed and simulated luge start speed, but not for baseball pitching accuracy or snowboarding ranking points. Prospective studies have shown that the addition of a balance training component to the activities of recreationally active subjects or physical education students has resulted in improvements in vertical jump, agility, shuttle run and downhill slalom skiing. A proposed mechanism for the enhancement in motor skills from balance training is an increase in the rate of force development. There are limited data on the influence of balance training on motor skills of elite athletes. When the effectiveness of balance training was compared with resistance training, it was found that resistance training produced superior performance results for

  4. N -annulated perylene as an efficient electron donor for porphyrin-based dyes: Enhanced light-harvesting ability and high-efficiency Co(II/III)-based dye-sensitized solar cells

    KAUST Repository

    Luo, Jie

    2014-01-08

    Porphyrin-based dyes recently have become good candidates for dye-sensitized solar cells (DSCs). However, the bottleneck is how to further improve their light-harvesting ability. In this work, N-annulated perylene (NP) was used to functionalize the Zn-porphyrin, and four "push-pull"-type NP-substituted and fused porphyrin dyes with intense absorption in the visible and even in the near-infrared (NIR) region were synthesized. Co(II/III)-based DSC device characterizations revealed that dyes WW-5 and WW-6, in which an ethynylene spacer is incorporated between the NP and porphyrin core, showed pantochromatic photon-to-current conversion efficiency action spectra in the visible and NIR region, with a further red-shift of about 90 and 60 nm, respectively, compared to the benchmark molecule YD2-o-C8. As a result, the short-circuit current density was largely increased, and the devices displayed power conversion efficiencies as high as 10.3% and 10.5%, respectively, which is comparable to that of the YD2-o-C8 cell (η = 10.5%) under the same conditions. On the other hand, the dye WW-3 in which the NP unit is directly attached to the porphyrin core showed a moderate power conversion efficiency (η = 5.6%) due to the inefficient π-conjugation, and the NP-fused dye WW-4 exhibited even poorer performance due to its low-lying LUMO energy level and nondisjointed HOMO/LUMO profile. Our detailed physical measurements (optical and electrochemical), density functional theory calculations, and photovoltaic characterizations disclosed that the energy level alignment, the molecular orbital profile, and dye aggregation all played very important roles on the interface electron transfer and charge recombination kinetics. © 2013 American Chemical Society.

  5. Endurance ability characteristics of professional sportsmen

    OpenAIRE

    Rozenstoka, Sandra

    2012-01-01

    Cycling and kettlebell sport are cyclic kinds of sport. For sport achievement is important the development of endurance ability. In kettlebell sport high performance is based on the strength endurance. One of the conditions for success in competition is sportsman’s high aerobic and anaerobic capacity. Complex cardiopulmonary exercise testing allows for simultaneous study of the responses of the cardiovascular and pulmonary systems to a stated physical load stress. There is direct correlation ...

  6. Cognitive abilities and creating metaphorical names

    Directory of Open Access Journals (Sweden)

    Avanesyan, Marina O.

    2016-06-01

    Full Text Available The cognitive processing of metaphor creation has been insufficiently investigated. Creating metaphors requires the ability to work in a fantastic, impossible context, using symbolic and associative means to express oneís thoughts. It has been shown recently that intelligence plays an important role in the creation of metaphors, but it is not the main factor in determining their success. The present research explores the roles of conceptual abilities, categorical abilities, and flexibility (as the factor creativity in metaphor creation. Participants (n = 38 young adults were asked to come up with names for three photos, without any special instruction to create metaphors. To classify conceptual abilities we used ìConceptual Synthesisî (M. A. Kholodnaya, 2012; to measure categorical ability we used the subtest ìSimilaritiesî (D. Wechsler, 1955; to identify the role of creativity in the metaphor process we used the test of ìUnusual Usesî (J. P. Guilford, 1960. The creation of complex metaphorical names was associated with a tendency to create highly organized mental structures and to retain them within the general semantic context (r = 0.344, p < 0.05. The tendency to create single-level situational connections was associated with a tendency to give specific names to photos (r = 0.475, p < 0.01. Photographic images proved out to be fruitful stimuli to investigate the processing of visual information. We developed a preliminary classification of names: 1 concrete; 2 situational; 3 abstract; 4 metaphorical (M1 and M2. We identified two types of metaphorical names — perceptual and complex metaphors — that relate to conceptual abilities in different ways. It is inaccurate to speak about a general concept of ìmetaphorical abilitiesî; we should differentiate the psychological mechanisms that lie at their base.

  7. Numerical ability predicts mortgage default.

    Science.gov (United States)

    Gerardi, Kristopher; Goette, Lorenz; Meier, Stephan

    2013-07-09

    Unprecedented levels of US subprime mortgage defaults precipitated a severe global financial crisis in late 2008, plunging much of the industrialized world into a deep recession. However, the fundamental reasons for why US mortgages defaulted at such spectacular rates remain largely unknown. This paper presents empirical evidence showing that the ability to perform basic mathematical calculations is negatively associated with the propensity to default on one's mortgage. We measure several aspects of financial literacy and cognitive ability in a survey of subprime mortgage borrowers who took out loans in 2006 and 2007, and match them to objective, detailed administrative data on mortgage characteristics and payment histories. The relationship between numerical ability and mortgage default is robust to controlling for a broad set of sociodemographic variables, and is not driven by other aspects of cognitive ability. We find no support for the hypothesis that numerical ability impacts mortgage outcomes through the choice of the mortgage contract. Rather, our results suggest that individuals with limited numerical ability default on their mortgage due to behavior unrelated to the initial choice of their mortgage.

  8. Sexual orientation and cognitive abilities.

    Science.gov (United States)

    Tuttle, G E; Pillard, R C

    1991-06-01

    We asked whether homosexual and heterosexual men and women differ on standard measures of cognitive ability. Subjects were adults recruited for a family study of sexual orientation. They completed the Fy Scale of the California Psychological Inventory, a self-administered measure of psychological "femininity," and were given subtests of the Wechsler Adult Intelligence Scale and the Primary Mental Abilities test which had been previously shown to discriminate between the sexes. We predicted that homosexual subjects would score significantly in the gender-atypical direction on the Fy scale. We also predicted that they would achieve scores on the tests of cognitive abilities significantly in the direction of the other gender. Comparisons were made between homosexual and heterosexual individuals within gender. Also, comparisons were made between heterosexual men and women to see if our results replicate differences typically found between the genders. As predicted, both homosexual men and women were strongly gender-atypical on the Fy scale relative to their heterosexual counterparts. However, neither differed from heterosexuals on any of the measures of cognitive abilities. Heterosexual men did better than women on the Primary Mental Abilities spatial relations test. We conclude that sexual orientation is not related to specific cognitive abilities.

  9. Arithmetic Abilities in Children With Developmental Dyslexia.

    Science.gov (United States)

    De Clercq-Quaegebeur, Maryse; Casalis, Séverine; Vilette, Bruno; Lemaitre, Marie-Pierre; Vallée, Louis

    2017-01-01

    A high comorbidity between reading and arithmetic disabilities has already been reported. The present study aims at identifying more precisely patterns of arithmetic performance in children with developmental dyslexia, defined with severe and specific criteria. By means of a standardized test of achievement in mathematics ( Calculation and Number Processing Assessment Battery for Children; von Aster & Dellatolas, 2006), we analyzed the arithmetic abilities of 47 French children with dyslexia attending 3rd, 4th, and 5th grade. Of them, 40% displayed arithmetic deficits, mostly with regard to number transcoding and mental calculation. Their individual profiles of performance accounted for varying strengths and weaknesses in arithmetic abilities. Our findings showed the pathway for the development of arithmetic abilities in children with dyslexia is not unique. Our study contrasts with the hypotheses suggesting the mutual exclusiveness of the phonological representation deficit and the core number module deficit.

  10. Sintered powder cores of high Bs and low coreloss Fe84.3Si4B8P3Cu0.7 nano-crystalline alloy

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2013-06-01

    Full Text Available Nano-crystalline Fe-rich Fe84.3Si4B8P3Cu0.7 alloy ribbon with saturation magnetic flux density (Bs close to Si-steel exhibits much lower core loss (Wt than Si-Steels. Low glass forming ability of this alloy limits fabrication of magnetic cores only to stack/wound types. Here, we report on fabrication, structural, thermal and magnetic properties of bulk Fe84.3Si4B8P3Cu0.7 cores. Partially crystallized ribbons (obtained after salt-bath annealing treatment were crushed into powdered form (by ball milling, and were compacted to high-density (∼88% bulk cores by spark plasma sintering (SPS. Nano-crystalline structure (consisting of α-Fe grain in remaining amorphous matrix similar to wound ribbon cores is preserved in the compacted cores. At 50 Hz, cores sintered at Ts = 680 K show Wt 1 kHz. A trade-off between porosity and electrical resistivity is necessary to get low Wt at higher f. In the f range of ∼1 to 100 kHz, we have shown that the cores mixed with SiO2 exhibit much lower Wt than Fe-powder cores, non-oriented Si-steel sheets and commercially available sintered cores. We believe our core material is very promising to make power electronics/electrical devices much more energy-efficient.

  11. Deafness and motor abilities level

    Directory of Open Access Journals (Sweden)

    A Zwierzchowska

    2008-09-01

    Full Text Available The audition injury hinders some motor motions and the organised coordination at the higher level and may be a cause of disturbances and disorder in some motor abilities adoption. It was assumed that deafness including its aetiology and injury mechanism may significantly influence the motor development of human being. The study aimed in checking if the deafness, as a result of various unfavourable factors, determines the motor development of children and youngsters. Consequently the dependency between qualitative features i.e.: signed motor level and aetiology, audition injury mechanism and the deafness degree was examined. The mechanism and aetiology of hearing correlated with the motor abilities displayed statistically significant dependencies in few motor trials only. Revealed correlations regarded mostly the coordination trials excluding the flexibility one. Statistically significant dependencies between the audition diminution and the motor abilities level were not found.

  12. Genetic transmission of reading ability

    NARCIS (Netherlands)

    Swagerman, Suzanne C.; Van Bergen, Elsje; Dolan, Conor; de Geus, Eco J. C.; Koenis, Marinka M.G.; Hulshoff Pol, Hilleke E.; Boomsma, Dorret I.

    2017-01-01

    Reading is the processing of written language. Family resemblance for reading (dis)ability might be due to transmission of a genetic liability or due to family environment, including cultural transmission from parents to offspring. Familial-risk studies exploring neurobehavioral precursors for

  13. Competence: Commodification of Human Ability

    Science.gov (United States)

    Han, Soonghee

    2008-01-01

    The purpose of this article is to analyze the meaning and presumptions of competence in the concrete context of knowledge capitalism. First, the nature of competence as a "commodification of human ability" that obtains a standardized monetary value to sell in the labor market, is elucidated by applying Karl Marx's critical theory. Second, it is…

  14. Spatial Ability, Sexism and Society.

    Science.gov (United States)

    Howes, Robin

    1980-01-01

    Indicates that women are eased out of science careers by factors other than a supposed lack of spatial ability. Advocates that the masculine bias in science be reduced through the humanization of science and technology and a realignment of societal goals. (GS)

  15. Emotional Intelligence and Leadership Abilities

    Science.gov (United States)

    Herbst, H. H.; Maree, J. G.; Sibanda, E.

    2006-01-01

    While exceptional leaders share certain qualities like a strong personal ethic and a compelling vision of the future, research has failed to provide conclusive "proof" of the link between a leader's effectiveness and his/ her emotional intelligence (defined from a cognitive perspective, as a set of abilities). Given the increased…

  16. Learning Ability and Memory Monitoring.

    Science.gov (United States)

    Yan, Wenfan

    1994-01-01

    The relationship between learning ability and memory-monitoring performance was studied for 289 undergraduates in a 5-stage feeling of knowing (FOK) procedure with confidence of recognition (COR) judgments. Results show that fast and slow learners do not differ in magnitude of FOK and COR. (SLD)

  17. INDIVIDUAL ABILITIES AND LIFELONG LEARNING

    Directory of Open Access Journals (Sweden)

    Oleksandr Yu. Burov

    2016-10-01

    Full Text Available This paper describes new and emerging technologies in education, learning environments and methods that have to satisfy lifelong learning, from school age to retirement, on the basis of the psychophysiological model of the cognitive abilities formation. It covers such topics as: evaluation of a human (accounting schoolchildren, youth and adults features abilities and individual propensities, individual trajectory of learning, adaptive learning strategy and design, recommendation on curriculum design, day-to-day support for individual’s learning, assessment of a human learning environment and performance, recommendation regards vocational retraining and/or further carrier etc.. The specific goal is to facilitate a broader understanding of the promise and pitfalls of these technologies and working (learning/teaching environments in global education/development settings, with special regard to the human as subject in the system and to the collaboration of humans and technical, didactic and organizational subsystems.

  18. Implicit learning as an ability.

    Science.gov (United States)

    Kaufman, Scott Barry; Deyoung, Colin G; Gray, Jeremy R; Jiménez, Luis; Brown, Jamie; Mackintosh, Nicholas

    2010-09-01

    The ability to automatically and implicitly detect complex and noisy regularities in the environment is a fundamental aspect of human cognition. Despite considerable interest in implicit processes, few researchers have conceptualized implicit learning as an ability with meaningful individual differences. Instead, various researchers (e.g., Reber, 1993; Stanovich, 2009) have suggested that individual differences in implicit learning are minimal relative to individual differences in explicit learning. In the current study of English 16-17year old students, we investigated the association of individual differences in implicit learning with a variety of cognitive and personality variables. Consistent with prior research and theorizing, implicit learning, as measured by a probabilistic sequence learning task, was more weakly related to psychometric intelligence than was explicit associative learning, and was unrelated to working memory. Structural equation modeling revealed that implicit learning was independently related to two components of psychometric intelligence: verbal analogical reasoning and processing speed. Implicit learning was also independently related to academic performance on two foreign language exams (French, German). Further, implicit learning was significantly associated with aspects of self-reported personality, including intuition, Openness to Experience, and impulsivity. We discuss the implications of implicit learning as an ability for dual-process theories of cognition, intelligence, personality, skill learning, complex cognition, and language acquisition. 2010 Elsevier B.V. All rights reserved.

  19. Discovery Learning for Mathematical Literacy Ability

    Science.gov (United States)

    Tokada, D.; Herman, T.; Suhendra

    2017-09-01

    The background of this research is students’ mathematical literacy ability which is still less so most students find difficulty in solving mathematical problem in daily life. Learning which tend to be teacher centered not give change to students to develop their own ideas so the students do not master the concept well. Discovery learning is one of learning which train students how to discover mathematical concept and to train students to express their ideas. This study is quasi experimental study which is aimed to find out the enhancement of mathematical literacy ability of eighth grade students with discovery learning. This research used nonequivalent control group design. The population in this research were all students of the eight grade Junior High School in Tana Toraja. This research conclude that mathematics learning with discovery learning method in eight grade students of Junior High School can enhance the ability of mathematical literacy more significant. Discovery learning give change to students to construct their own knowledge so they can understand mathematical problem until its solution.

  20. Profile of student critical thinking ability on static fluid concept

    Science.gov (United States)

    Sulasih; Suparmi, A.; Sarwanto

    2017-11-01

    Critical thinking ability is an important part of educational goals. It has higher complex processes, such as analyzing, synthesizing and evaluating, drawing conclusion and reflection. This study is aimed to know the critical thinking ability of students in learning static fluids of senior high school students. This research uses the descriptive method which its instruments based on the indicator of critical thinking ability developed according to Ennis. The population of this research is XIth grade science class Public Senior High School, SMA N 1, Sambungmacan, Sragen, Central Java. The static fluid teaching material is delivered using Problem Based Learning Model through class experiment. The results of this study shows that the average student of XIth science class have high critical thinking skills, particularly in the ability of providing simple explanation, build basic skill, and provide advanced explanation, but they do not have high enough in ability of drawing conclusion and strategic and tactical components of critical thinking ability in the study of static fluid teaching material. The average of students critical thinking ability is 72.94, with 27,94% of students are in a low category and 72,22% of students in the high category of critical thinking ability.

  1. Combining ability of twelve maize populations

    Directory of Open Access Journals (Sweden)

    Vacaro Elton

    2002-01-01

    Full Text Available Genetic progress depends on germplasm quality and breeding methods. Twelve maize populations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA and specific (SCA combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxerê, suggested the environmental influence on the manifestation of this genetic phenomenon. Populations revealed potential to be used in breeding programs; however, those more intensively submitted to selection could provide larger genetic progress, showing the importance of population improvement for the increment of the heterosis in maize.

  2. Adolescent substance users: problem-solving abilities.

    Science.gov (United States)

    Frank, A; Green, V; McNeil, D W

    1993-01-01

    Cognitive ability and cognitive egocentrism were examined as predictors of problem-solving ability in adolescent substance users in a vocational training program. Problem-solving outcome variables were significantly predicted by two cognitive ability measures, as well as by measures of cognitive independence and egocentrism in thinking. Extent of substance use did not affect cognitive ability, cognitive egocentrism, or problem-solving ability.

  3. Do the Effects of Working Memory Training Depend on Baseline Ability Level?

    Science.gov (United States)

    Foster, Jeffrey L.; Harrison, Tyler L.; Hicks, Kenny L.; Draheim, Christopher; Redick, Thomas S.; Engle, Randall W.

    2017-01-01

    There is a debate about the ability to improve cognitive abilities such as fluid intelligence through training on tasks of working memory capacity. The question addressed in the research presented here is who benefits the most from training: people with low cognitive ability or people with high cognitive ability? Subjects with high and low working…

  4. Spatial Ability: A Neglected Talent in Educational and Occupational Settings

    Science.gov (United States)

    Kell, Harrison J.; Lubinski, David

    2013-01-01

    For over 60 years, longitudinal research on tens of thousands of high ability and intellectually precocious youth has consistently revealed the importance of spatial ability for hands-on creative accomplishments and the development of expertise in science, technology, engineering, and mathematical (STEM) disciplines. Yet, individual differences in…

  5. Drop Jumping as a Training Method for Jumping Ability

    NARCIS (Netherlands)

    Bobbert, Maarten F.

    1990-01-01

    Vertical jumping ability is of importance for good performance in sports such as basketball and volleyball. Coaches are in need of exercises that consume only little time and still help to improve their players’ jumping ability, without involving a high risk of injury. Drop jumping is assumed to

  6. Crystallization behavior and magnetic properties in High Fe content FeBCSiCu alloy system

    Energy Technology Data Exchange (ETDEWEB)

    Fan, X.D., E-mail: fanxd@seu.edu.cn; Shen, B.L., E-mail: blshen@seu.edu.cn

    2015-07-01

    High Fe content FeBCSiCu nanocrystalline alloys are prepared by annealing melt-spun amorphous ribbons with aim at increasing saturation magnetic flux density. Microstructures identified by XRD and TEM reveal that Cu addition inhibits the surface crystallization of Fe{sub 86}B{sub 7}C{sub 7} alloy and improve its glass-forming ability. Activation energy of crystallization calculated by Kissinger's equation indicates that both Cu and Si addition promotes the precipitation of α-Fe phase and improves the thermal stability. VSM and DC B–H loop tracer measurements show that the Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy exhibits high saturation magnetic flux density of 1.8 T and low coercivity of 10 A/m, respectively. AC properties measured by AC B–H analyzer show this alloy exhibits low core loss of 0.35 W/kg at 1 T at 50 Hz. Low material cost and convenient productivity make the Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy an economical application in industry. - Highlights: • Cu addition inhibits the surface crystallization and improves the GFA. • The competitive formation of Fe{sub 3}C and α-Fe phase impedes the devitrification. • Fe{sub 85.5}B{sub 7}C{sub 6}Si{sub 1}Cu{sub 0.5} nanocrystalline alloy exhibits excellent magnetic properties. • The alloy system has an economical advantage and convenient productivity.

  7. Videogame interventions and spatial ability interactions

    National Research Council Canada - National Science Library

    Redick, Thomas S; Webster, Sean B

    2014-01-01

    .... In the current work, we investigate the available evidence for transfer specifically to nonverbal intelligence and spatial ability measures, given recent research that these abilities may be most...

  8. The Data Set on the Multiple Abilities

    DEFF Research Database (Denmark)

    Klynge, Alice Heegaard

    2008-01-01

    This paper presents a data set on multiple abilities. The abilities cover the Literacy and Math Ability, the Creative and Innovative Ability, the Learning Ability, the Communication Ability, the Social Competency, the Self-Management Ability, the Environmental Awareness, the Civic Competency......, the Intercultural Awareness, and the Health Awareness. The data stems from a unique cross-sectional survey carried out for the adult population in Denmark. Several dimensions and many questions pinpoint and measure every ability. The dimensions cover areas such as the individual behavior at work, the individual...

  9. Assessment of the ability of a fourth-generation immunoassay for human immunodeficiency virus (HIV) antibody and p24 antigen to detect both acute and recent HIV infections in a high-risk setting.

    Science.gov (United States)

    Pandori, Mark W; Hackett, John; Louie, Brian; Vallari, Ana; Dowling, Teri; Liska, Sally; Klausner, Jeffrey D

    2009-08-01

    An immunoassay (IA) that simultaneously detects both antibody to human immunodeficiency virus (HIV) and HIV p24 antigen (Architect HIV Ag/Ab Combo) was evaluated for its ability to detect HIV infection by using a panel of specimens collected from individuals recently infected with HIV type 1 (HIV-1). This IA was found to be capable of detecting the majority (89%) of infections, including 80% of those considered acute infections based on the presence of HIV RNA and the lack of detectable antibody to HIV. Substantial improvements in detection of recent infections by the Architect HIV Ag/Ab Combo relative to previous generations of IAs as well as the capacity to detect acute infections have important implications for HIV prevention strategies.

  10. Teaching Mixed Ability Work in the Fourth and Fifth Years.

    Science.gov (United States)

    Jones, Pat

    1979-01-01

    The head of the English department at a senior high school explains the organizational and curricular adaptations that have made their practice of mixed-ability teaching a success. Sample English lessons are described. (SJL)

  11. Gender, culture, and sex-typed cognitive abilities

    National Research Council Canada - National Science Library

    Reilly, David

    2012-01-01

    Although gender differences in cognitive abilities are frequently reported, the magnitude of these differences and whether they hold practical significance in the educational outcomes of boys and girls is highly debated...

  12. Effect of clinical practice on self-learning development ability

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hyun; Yang, Han Joon [Dept. of International Radiological Science, Hallym University of Graduate Studies, Chuncheon (Korea, Republic of); Kim, Nak Sang [Dept. of Radiological Science, Songho College, Hoengseong (Korea, Republic of)

    2017-09-15

    In order to analyze the degree of self-learning development ability after the clinical training curriculum, the results of 121 questionnaires were analyzed for 3rd and 4th grade students in radiology in the metropolitan area. The overall average of self-learning ability according to gender was 3.07±0.85, which was statistically significant according to gender. However, the results according to educational system showed that the overall average was 3.07±0.85, which was higher than the average level of self-learning development ability. There was no statistically significant difference according to educational system. The results of the self-learning development ability according to the motivation for selecting the department showed that the students who have chosen their department due to their higher employment rate after graduation had high self-development ability level(3.58±0.85) but the students who entered the school due to self-aptitude had relatively lower self-development ability level (2.30±0.40). The overall average of self-learning ability according to direction of career path was 3.08±0.76, which was over-average of self-learning development ability. Thus, there was statistically significant difference according to career path. It is necessary to improve the self-learning ability in clinical practice. In addition, the lack of statistical significance suggests problems and diversity.

  13. Self-assembly formation of Bi-functional Co3O4/MnO2-CNTs hybrid catalysts for achieving both high energy/power density and cyclic ability of rechargeable zinc-air battery

    National Research Council Canada - National Science Library

    Xu, Nengneng; Liu, Yuyu; Zhang, Xia; Li, Xuemei; Li, Aijun; Qiao, Jinli; Zhang, Jiujun

    2016-01-01

    .... When integrated into the practical primary and electrochemically rechargeable Zn-air batteries, such a hybrid catalyst can give a discharge peak power density as high as 450 mW cm(-2). At 1.0...

  14. Combining ability's for yield components in sunflower

    Directory of Open Access Journals (Sweden)

    Hladni Nada

    2000-01-01

    Full Text Available In order to develop new single-cross sunflower hybrids with an altered plant model and a high genetic potential for seed yield and oil content, it is essential to study the combining ability's of the inbred lines. Full diallel crosses with six genetically divergent sunflower inbreeds were carried out in order to study the mode of inheritance and combining ability for plant height and head diameter in the F1 and F2 generations. Significant differences in the mean values for the traits concerned were observed. The most common mode of inheritance of plant height in the F1 and F2 generations was super dominance, and there were also instances of partial dominance and dominance. The mode of inheritance of head diameter in the F1 and F2 generations was dominance and super dominance. Highly significant GCA and SCA value, for plant height and head diameter were recorded. We found a line (NS-NDF with negative GCA value that was also a good genera 1 combiner for reduced plant height and head diameter. .

  15. Students' Thinking about Effort and Ability: The Role of Developmental, Contextual, and Individual Difference Factors

    Science.gov (United States)

    Muenks, Katherine; Miele, David B.

    2017-01-01

    Students' thinking about the relation between effort and ability can influence their motivation, affect, and academic achievement. Students sometimes think of effort as inversely related to ability (such that people with low ability must work harder than people with high ability) and other times think of effort as positively related to ability…

  16. An Examination of the Ability of High School Wealth and Academic Preparation to Predict First Year Retention of African American and White Students Enrolled in the North Carolina Community College System Associate Degree of Nursing Programs

    Science.gov (United States)

    Patton, Bess Llewellyn

    2016-01-01

    The framework for this study used Tinto's (1975) theoretical framework for student persistence and incorporated the examination of high school wealth, the absence of poverty, as measured by the percentage of students receiving Federal Free and Reduced Lunch, along with North Carolina Department of Public School performance measures, academic…

  17. Dimensions of affect modulated by perceived mood regulation ability.

    Science.gov (United States)

    Hovanitz, Christine A; Hursh, Adrienne N; Hudepohl, Adam D

    2011-06-01

    The ability to regulate mood is a facet of emotional intelligence that may contribute to an individual's physical and mental health. Precisely what is regulated when mood regulation occurs is dependent on what "makes up" mood. The purpose of this study was to evaluate whether perceived mood regulation ability can predict regulation of affect during task engagement and whether affect regulation is specific to valence or arousal. Measures of positive affect, negative affect, and frontal area sEMG (as a measure of arousal) were obtained from a sample of one hundred twenty-four participants categorized by their self report as possessing low or high mood regulation ability. Modulation of positive affect, but not negative affect, was predicted by perceived mood regulation ability. The results of sEMG were mixed. These data provide some support for the hypothesis that mood regulation ability can predict future efforts to regulate affect, at least in the context of task engagement.

  18. [Temperature storage ability and radiation ability of rotating anodes in high-performance roentgen tubes].

    Science.gov (United States)

    Schreiber, P

    1983-09-01

    In long time or serial operation metal anode discs with blackened layer can be loaded much higher than graphite anode discs, because the distance between thermal source and temperature sensitive spot in metal discs is larger than in graphite discs and the maximum permissible temperature for metal discs is much higher than that for graphite discs.

  19. Quantile forecast discrimination ability and value

    DEFF Research Database (Denmark)

    Ben Bouallègue, Zied; Pinson, Pierre; Friederichs, Petra

    2015-01-01

    While probabilistic forecast verification for categorical forecasts is well established, some of the existing concepts and methods have not found their equivalent for the case of continuous variables. New tools dedicated to the assessment of forecast discrimination ability and forecast value are ...... is illustrated based on synthetic datasets, as well as for the case of global radiation forecasts from the high resolution ensemble COSMO-DE-EPS of the German Weather Service.......While probabilistic forecast verification for categorical forecasts is well established, some of the existing concepts and methods have not found their equivalent for the case of continuous variables. New tools dedicated to the assessment of forecast discrimination ability and forecast value...... are introduced here, based on quantile forecasts being the base product for the continuous case. The relative user characteristic (RUC) curve and the quantile value plot allow analysing the performance of a forecast for a specific user in a decision-making framework. The RUC curve is designed as a user...

  20. Improving leaping ability in elite rhythmic gymnasts.

    Science.gov (United States)

    Hutchinson, M R; Tremain, L; Christiansen, J; Beitzel, J

    1998-10-01

    The purpose of this study was to improve the leaping ability of athletes in rhythmic gymnastics, a high leap demanding sport, using a controlled course of jump training. Six elite athletes underwent a course of leap training including pool training and Pilates' Method of Body Conditioning using spring controlled resistance to muscular exertion. Baseline data was obtained on a force plate that measured reaction time, leap height, and explosive power on each athlete before initiating training. After 1 month of training, leap height improved 16.2%, ground reaction time improved 50%, and explosive power improved 220%. With continued maintenance training, no decrease in effect was noted; however, no significant improvement occurred after the first month of training. At 1 yr with discontinuation of the leaping protocol but continued training within the sport, the initial gains were likewise maintained. No injuries occurred during participation in the leaping protocol. Elite rhythmic gymnasts can safely improve their leaping ability significantly through an intense course of jump training. Continued training with the leaping protocol does not appear to further enhance the benefit; however, the gains appear to be maintained at 4 months and 1 yr post training with or without additional training with the leaping protocol.

  1. Improvement of Speaking Ability through Interrelated Skills

    Science.gov (United States)

    Liao, Guoqiang

    2009-01-01

    How to improve students' ability of speaking English? That is the key point we are concerned about. This paper discusses the possibility and necessity of improving students' ability by combining the four skills of speaking, listening, reading and writing.

  2. Self-assembly formation of Bi-functional Co3O4/MnO2-CNTs hybrid catalysts for achieving both high energy/power density and cyclic ability of rechargeable zinc-air battery

    Science.gov (United States)

    Xu, Nengneng; Liu, Yuyu; Zhang, Xia; Li, Xuemei; Li, Aijun; Qiao, Jinli; Zhang, Jiujun

    2016-09-01

    α-MnO2 nanotubes-supported Co3O4 (Co3O4/MnO2) and its carbon nanotubes (CNTs)-hybrids (Co3O4/MnO2-CNTs) have been successfully developed through a facile two-pot precipitation reaction and hydrothermal process, which exhibit the superior bi-functional catalytic activity for both ORR and OER. The high performance is believed to be induced by the hybrid effect among MnO2 nanotubes, hollow Co3O4 and CNTs, which can produce a synergetic enhancement. When integrated into the practical primary and electrochemically rechargeable Zn-air batteries, such a hybrid catalyst can give a discharge peak power density as high as 450 mW cm-2. At 1.0 V of cell voltage, a current density of 324 mA cm-2 is achieved. This performance is superior to all reported non-precious metal catalysts in literature for zinc-air batteries and significantly outperforms the state-of-the-art platinum-based catalyst. Particularly, the rechargeable Zn-air battery can be fabricated into all-solid-state one through a simple solid-state approach, which exhibits an excellent peak power density of 62 mW cm-2, and the charge and discharge potentials remain virtually unchanged during the overall cycles, which is comparable to the one with liquid electrolyte.

  3. Predicting Academic Achievement with Cognitive Ability

    Science.gov (United States)

    Rohde, Treena Eileen; Thompson, Lee Anne

    2007-01-01

    The purpose of the present study is to explain variation in academic achievement with general cognitive ability and specific cognitive abilities. Grade point average, Wide Range Achievement Test III scores, and SAT scores represented academic achievement. The specific cognitive abilities of interest were: working memory, processing speed, and…

  4. TIE: An Ability Test of Emotional Intelligence

    Science.gov (United States)

    Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S.

    2014-01-01

    The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions. PMID:25072656

  5. TIE: an ability test of emotional intelligence.

    Science.gov (United States)

    Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S

    2014-01-01

    The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions.

  6. TIE: an ability test of emotional intelligence.

    Directory of Open Access Journals (Sweden)

    Magdalena Śmieja

    Full Text Available The Test of Emotional Intelligence (TIE is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions.

  7. Heritability, combining ability and inheritance of storage root dry ...

    African Journals Online (AJOL)

    Significant (p<0.001) mean squares for general combining ability (GCA), and specific combining ability (SCA) were observed in F1 and F2 generations, demonstrating additive and non-additive genetic inheritance of RDM. High Baker's ratio in F1 (0.76) and F2 (0.78), and large σ2GCA/σ2SCA (3.13) indicate predominance ...

  8. Coordinating abilities in structure of special preparation of combat athletes

    Directory of Open Access Journals (Sweden)

    Klymenko A.I.

    2010-03-01

    Full Text Available Development tendency of modern sport assumes high competition and as a result, training and competitive pressure. This requires from the coach to search for new methods of increasing effectiveness of the training process without increasing the pressure volume and intensiveness. One of the ways of solving this problem is the development of a method of increasing coordinating abilities. Several types of coordinating abilities of wrestlers. Deals with methodical peculiarities or perfection and means of increasing coordinating of sambo.

  9. A influência do desejo parental nas altas habilidades/superdotação: uma abordagem psicanalítica The influence of the parental desire in the high abilities/superendowment: a psychoanalytical approach

    Directory of Open Access Journals (Sweden)

    Janaína Pereira Pretto

    2010-10-01

    Full Text Available TEMA: O presente trabalho busca discutir as altas habilidades/superdotação, através de uma leitura psicanalítica, propondo estudar a superdotação como se constituindo em uma forma peculiar de responder ao fantasma parental, sobretudo, com o que se relaciona ao desejo materno, colocando-se como algo que está além da estrutura, presente tanto na neurose, quanto na perversão e psicose. A partir disso, será abordada a concepção psicanalítica do processo de estruturação psíquica, dando ênfase na constituição neurótica do sujeito, a fim de circunscrever de que forma o mesmo se encontra referido ao significante superdotado e como isso se refletirá em sua relação com o saber. Sendo assim, será analisada a noção de estrutura psíquica e de inconsciente estruturado, verificando como essa teoria introduz a figura materna no processo de constituição psíquica do sujeito e como isso reflete nos processos cognitivos. Para este estudo, foi realizada uma pesquisa qualitativa, do tipo bibliográfica, onde foram selecionados livros e artigos capazes de explicar o tema proposto. OBJETIVO: buscar entender como o elevado desempenho intelectual do superdotado surge como uma forma de atender ao desejo narcísico dos pais. CONCLUSÃO: de acordo com a revisão de literatura, a criança superdotada, embora de uma forma inconsciente, pode ser um substituto capaz de recobrir as perdas da infância, o retorno ao tempo perdido, os amores perdidos, os ideais parentais, atendendo prontamente à demanda incondicional do Outro. Neste sentido, as altas habilidades/superdotação surgem como um traço, direcionado a responder ao fantasma parental, sobretudo naquilo que este se relaciona ao desejo materno.BACKGROUND: This work aims to discuss the high skills / superendowment, through apsychoanalytical reading, in where we propose to study the superendowment as constituting a peculiar to answer the parental ghost, above all, with what is related to the

  10. Anxiety and ability to recognize clinical information in dentistry.

    Science.gov (United States)

    Eli, I; Schwartz-Arad, D; Bartal, Y

    2008-01-01

    Stress significantly affects a person's cognitive ability to process information. Therefore, we hypothesized that patients' ability to recognize information related to the procedure they are about to undergo will be affected by the stressfulness of the situation (less recognition under a high-stress situation as compared with a low-stress situation). Patients (n = 66) were evaluated for their ability to recognize clinical information supplied on two different occasions: immediately before oral surgery (high-stress condition) and before suture removal (low-stress condition). Dental and state of anxiety and expectation of pain were also assessed. On both occasions, the patients' ability to recognize information correctly was low (less than 50%). Patients recognized significantly less information pre-operatively than before suture removal. State of anxiety, dental anxiety, and expectation to experience pain had a profound effect on their ability to recognize provided information correctly. Apparently, before dental treatment (high or low on stress), patients' ability to process information may be severely impaired.

  11. Athletics for All: Providing Opportunities for Students of All Abilities

    Science.gov (United States)

    Whitmer, Regina

    2013-01-01

    The glory days of high school sports are no longer reserved for dream team athletes, as athletic directors are increasingly opening up sports to all students, regardless of ability, and seeing winning results on the field and off. This push is reflected in the most recent National Federation of State High School Associations (NFHS) survey, which…

  12. Concept mapping learning strategy to enhance students' mathematical connection ability

    Science.gov (United States)

    Hafiz, M.; Kadir, Fatra, Maifalinda

    2017-05-01

    The concept mapping learning strategy in teaching and learning mathematics has been investigated by numerous researchers. However, there are still less researchers who have scrutinized about the roles of map concept which is connected to the mathematical connection ability. Being well understood on map concept, it may help students to have ability to correlate one concept to other concept in order that the student can solve mathematical problems faced. The objective of this research was to describe the student's mathematical connection ability and to analyze the effect of using concept mapping learning strategy to the students' mathematical connection ability. This research was conducted at senior high school in Jakarta. The method used a quasi-experimental with randomized control group design with the total number was 72 students as the sample. Data obtained through using test in the post-test after giving the treatment. The results of the research are: 1) Students' mathematical connection ability has reached the good enough level category; 2) Students' mathematical connection ability who had taught with concept mapping learning strategy is higher than who had taught with conventional learning strategy. Based on the results above, it can be concluded that concept mapping learning strategycould enhance the students' mathematical connection ability, especially in trigonometry.

  13. Amplified spontaneous emission of glass forming DCM derivatives in PMMA films

    Science.gov (United States)

    Vembris, Aivars; Zarinsh, Elmars; Kokars, Valdis

    2014-05-01

    4-(dicyanomethylene)-2-methyl- 6-(p-dimethylaminostyryl)-4H-pyran (DCM) is well known red laser dye which can be used also in solid state organic lasers. The lowest threshold value of amplified spontaneous emission was achieved by doping 2wt% of DCM molecule in tris-(8-hydroxy quinoline) aluminium (Alq3) matrix. Further increase of dye concentration also increases threshold value. It is due to large intermolecular interaction which reduce photoluminescence quantum yield. Compounds with small intermolecular interaction and which exhibit similar amplified spontaneous properties as DCM could be useful for solid state organic lasers. In the work photoluminescence and amplified spontaneous emission properties of two DCM derivatives in poly (methyl methacrylate) (PMMA) matrix were investigated. Bulky trityloxyethyl groups are attached to the donor part of investigated molecules. These groups reduce intermolecular distance wherewith reduce photoluminescence quenching. More than one order of magnitude lower excitation threshold energy of the amplified spontaneous emission was achieved in doped polymer films with investigated compound in comparison to doped polymer with DCM. It means that the investigated compound is more perspective as a laser material compared to previously study.

  14. Hydrogen motions and the α-relaxation in glass-forming polymers ...

    Indian Academy of Sciences (India)

    J Colmenero1 2 3 A Arbe2 F Alvarez1 2 A Narros1 D Richter4 M Monkenbush4 B Farago5. Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales CSIC-UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, ...

  15. Conventional methods fail to measure cp(omega) of glass-forming liquids

    DEFF Research Database (Denmark)

    Christensen, Tage Emil; Olsen, Niels Boye; Dyre, Jeppe

    2007-01-01

    thermal-wave method does not measure the isobaric frequency-dependent specific heat cp(omega). This method rather measures a "longitudinal" frequency-dependent specific heat, a quantity defined and detailed here that is in between cp(omega) and cV(omega). This result means that no reliable wide......-frequency measurements of cp(omega) on liquids approaching the calorimetric glass transition exist. We briefly discuss consequences for experiment....

  16. Elastic models for the non-Arrhenius viscosity of glass-forming liquids

    DEFF Research Database (Denmark)

    Dyre, Jeppe; Christensen, Tage Emil; Olsen, Niels Boye

    2006-01-01

    This paper first reviews the shoving model for the non-Arrhenius viscosity of viscous liquids. According to this model the main contribution to the activation energy of a flow event is the energy needed for molecules to shove aside the surrounding, an energy which is proportional to the instantan......This paper first reviews the shoving model for the non-Arrhenius viscosity of viscous liquids. According to this model the main contribution to the activation energy of a flow event is the energy needed for molecules to shove aside the surrounding, an energy which is proportional...... on to review several related explanations for the non-Arrhenius viscosity. Most of these are also ‘elastic models’, i.e., they express the viscosity activation energy in terms of short-time elastic properties of the liquid. Finally, two alternative arguments for elastic models are given, a general solid...

  17. Polymorphous-Crystalloid Structure and Relaxation Processes in Some Chalcogenide Glass-Forming Substances

    Science.gov (United States)

    2001-06-01

    0. Uemura, Y. Sagara, D. Muro , T. Satow, J.Non-Crystalline Solids, 30, 155 (1978). [31] Y. Wang, M. Nakamura, 0. Matsuda, I. Inoue, K. Murase, J.Non...physics of selenium and tellurium. Eds. E. Gerlach, P. Grosse. Springer Vorlag. Berlin -Heidelberg-New-York, 178 (1979). [46] V. S. Minaev, Proceed. 18th

  18. Electrical Conductivity in Glass-Forming Solid Electrolytes: Theory and Experiment

    National Research Council Canada - National Science Library

    Bendler, J

    2001-01-01

    ...(dimethylsiloxane-ethylene-oxide) complexed with NaCF3COO. In the defect diffusion model, ion transport is controlled by defects and ion motion occurs when the ion is encountered by a single defect...

  19. Dynamics of glass-forming liquids: Will theory and experiment ever meet?

    DEFF Research Database (Denmark)

    Hansen, Henriette Wase

    2018-01-01

    cell to locate isochrones, i.e. lines of constant alpha relaxation time in temperature and pressure with the purpose of testing isomorph theory on three systems, two simple van der Waals and a hydrogen bonded liquid. We find density scaling and isochronal superpositioning to hold for all three systems...... on alpha relaxation dynamics, and for the two van der Waals liquids, also when we have separation of timescales, i.e. the alpha relaxation is not contributing to the picosecond dynamics. The concept of isomorphs is observed to break down in two cases for the hydrogen bonding system: in density scaling...... of intramolecular motion and in isochronal superposition of the picosecond dynamics when there is separation of timescales. We show for one of the van der Waals liquids how the picosecond dynamics can be expressed as a function of the alpha relaxation time in agreement with the prediction of the existence of a one...

  20. Study of the Boson Peak and Fragility of Bioprotectant Glass-Forming Mixtures by Neutron Scattering

    Directory of Open Access Journals (Sweden)

    F. Migliardo

    2013-01-01

    Full Text Available The biological relevance of trehalose, glycerol, and their mixtures in several anhydrobiotic and cryobiotic organisms has recently promoted both experimental and simulation studies. In addition, these systems are employed in different industrial fields, such as pharmaceutical and cosmetic industries, as additives in mixtures for cryopreservation and in several formulations. This review article shows an overview of Inelastic Neutron Scattering (INS data, collected at different temperature values by the OSIRIS time-of-flight spectrometer at the ISIS Facility (Rutherford Appleton Laboratory, Oxford, UK and by the IN4 and IN6 spectrometers at the Institut Laue Langevin (ILL, Grenoble, France, on trehalose/glycerol mixtures as a function of the glycerol content. The data analysis allows determining the Boson peak behavior and discussing the findings in terms of fragility in relation to the bioprotective action of trehalose and glycerol.

  1. Preparation of glass-forming materials from granulated blast furnace slag

    Science.gov (United States)

    Alonso, M.; Sáinz, E.; Lopez, F. A.

    1996-10-01

    Glass precursor materials, to be used for the vitrification of hazardous wastes, have been prepared from blast furnace slag powder through a sol-gel route. The slag is initially reacted with a mixture of alcohol (ethanol or methanol) and mineral acid (HNO3 or H2SO4) to give a sol principally consisting of Si, Ca, Al, and Mg alkoxides. Gelation is carried out with variable amounts of either ammonia or water. The gelation rate can be made as fast as desired by adding excess hydrolizing agent or else by distilling the excess alcohol out of the alkoxide solution. The resulting gel is first dried at low temperature and ground. The powder thus obtained is then heat treated at several temperatures. The intermediate and final materials are characterized by thermal analysis, infrared (IR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and chemical analysis. From the results, the operating conditions yielding a variety of glass precursors differing in their composition are established. The method, in comparison with direct vitrification of slag, presents a number of advantages: (1) the glass precursor obtained devitrifies at higher temperatures; (2) it enables the adjustment, to a certain extent, of the chemical composition of the glass precursor; and (3) it permits recovering marketable materials at different stages of the process.

  2. Potential energy landscape signatures of slow dynamics in glass forming liquids

    DEFF Research Database (Denmark)

    Sastry, S.; Debenedetti, P. G.; Stillinger, F. H.

    1999-01-01

    We study the properties of local potential energy minima (‘inherent structures’) sampled by liquids at low temperatures as an approach to elucidating the mechanisms of the observed dynamical slowing down observed as the glass transition temperature is approached. This onset of slow dynamics is ac...

  3. Hydrogen motions and the α-relaxation in glass- forming polymers ...

    Indian Academy of Sciences (India)

    NS on protonated samples is directly related with the self-part of the van Hove correlation function Gs( r, ... NS investigations have allowed to establish a universal behaviour for the self-atomic motions in the. 25 ..... Commission under the “Access to Research Infrastructures Action of the Human. Potential Programme: ...

  4. Is Cu60Ti10Zr30 a bulk glass-forming alloy?

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Saida, J.; Kato, H.

    2003-01-01

    The microstructures of Cu60Ti10Zr30 alloys fabricated by using two different methods, (rods of 2.5 mm in diameter prepared by a copper-mold casting method, and ribbons of about 0.03 mm in thickness prepared by the melt-spinning method), have been investigated by transmission electron microscopy a...

  5. Unifying different interpretations of the nonlinear response in glass-forming liquids

    Science.gov (United States)

    Gadige, P.; Albert, S.; Michl, M.; Bauer, Th.; Lunkenheimer, P.; Loidl, A.; Tourbot, R.; Wiertel-Gasquet, C.; Biroli, G.; Bouchaud, J.-P.; Ladieu, F.

    2017-09-01

    This work aims at reconsidering several interpretations coexisting in the recent literature concerning nonlinear susceptibilities in supercooled liquids. We present experimental results on glycerol and propylene carbonate, showing that the three independent cubic susceptibilities have very similar frequency and temperature dependences, for both their amplitudes and phases. This strongly suggests a unique physical mechanism responsible for the growth of these nonlinear susceptibilities. We show that the framework proposed by two of us [J.-P. Bouchaud and G. Biroli, Phys. Rev. B 72, 064204 (2005), 10.1103/PhysRevB.72.064204], where the growth of nonlinear susceptibilities is intimately related to the growth of glassy domains, accounts for all the salient experimental features. We then review several complementary and/or alternative models and show that the notion of cooperatively rearranging glassy domains is a key (implicit or explicit) ingredient to all of them. This paves the way for future experiments, which should deepen our understanding of glasses.

  6. Second-order nonlinear optical properties of mexylaminotriazine-functionalized glass-forming azobenzene derivatives

    Science.gov (United States)

    Umezawa, Hirohito; Jackson, Matthew; Lebel, Olivier; Nunzi, Jean-Michel; Sabat, Ribal Georges

    2016-10-01

    The second-order nonlinear optical coefficients of thin films of mexylaminotriazine-functionalized azobenzene molecular glass derivatives were measured using second harmonic generation. The thin films were poled using a custom corona poling set-up and the second harmonic light from a pulsed 1064-nm laser was detected. Four out of the six tested compounds showed optical nonlinearity and a maximum coefficient of 75 pm/V was obtained. The time dependence of the nonlinear coefficients was studied under ambient light and under dark; the second harmonic generation intensity stayed constant for thiazole-containing derivatives while a significant decay was measured for the other compounds.

  7. Characterization of 'strong-fragile' behaviour of glass-forming aqueous solutions by neutron scattering

    CERN Document Server

    Branca, C; Galli, G; Magazù, S; Maisano, G; Migliardo, F

    2002-01-01

    Neutron-scattering measurements have been performed on trehalose/H sub 2 O and sucrose/H sub 2 O mixtures by using the spectrometer MIBEMOL at the Laboratoire Leon Brillouin (LLB, Saclay) as a function of temperature and concentration. In order to characterize the different rigidities of both the disaccharide/H sub 2 O mixtures, we have evaluated the R sub 1 (T sub g) parameter connected to the 'strong-fragile' classification of the systems according to Angell's nomenclature. (orig.)

  8. Comment on "Dynamic viscosity of a simple glass-forming liquid"

    DEFF Research Database (Denmark)

    Christensen, Tage Emil; Olsen, Niels Boye; Dyre, Jeppe

    1996-01-01

    A Comment on the Letter by Narayanan Menon, Sidney R. Nagel, and David C. Venerus, Phys. Rev. Lett. 73, 963 (94). The authors of the Letter offer a Reply.......A Comment on the Letter by Narayanan Menon, Sidney R. Nagel, and David C. Venerus, Phys. Rev. Lett. 73, 963 (94). The authors of the Letter offer a Reply....

  9. Risk aversion relates to cognitive ability

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making rather than to risk preferences....

  10. Risk Aversion Relates to Cognitive Ability

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl

    2016-01-01

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making, rather than to risk preferences....

  11. Who Multi-Tasks and Why? Multi-Tasking Ability, Perceived Multi-Tasking Ability, Impulsivity, and Sensation Seeking

    Science.gov (United States)

    Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.

    2013-01-01

    The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants’ perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation – high levels of impulsivity and sensation seeking – reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control - low scorers on the Operation Span task and persons high in impulsivity - tended to report higher levels of multi-tasking activity. PMID:23372720

  12. Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

    Directory of Open Access Journals (Sweden)

    David M Sanbonmatsu

    Full Text Available The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

  13. Who multi-tasks and why? Multi-tasking ability, perceived multi-tasking ability, impulsivity, and sensation seeking.

    Science.gov (United States)

    Sanbonmatsu, David M; Strayer, David L; Medeiros-Ward, Nathan; Watson, Jason M

    2013-01-01

    The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.

  14. International, High-Ability Adventures: An Interview with Miraca Gross

    Science.gov (United States)

    Henshon, Suzanna E.

    2006-01-01

    This article presents an interview with Dr. Miraca Gross, Professor of Gifted Education, and Director of the Gifted Education Research, Resource, and Information Centre (GERRIC), at the University of New South Wales in Sydney, Australia. Dr. Gross is a leading international authority on the education of gifted and talented children, particularly…

  15. Socioeconomic Inequality and Giftedness: Suppression and Distortion of High Ability

    Science.gov (United States)

    Ambrose, Don

    2013-01-01

    Severe socioeconomic inequality strongly suppresses and distorts the discovery of aspirations and the concomitant development of talents among the gifted. More comprehensive understanding of this suppression and distortion is available through a wide-ranging interdisciplinary search for research findings and theories that illuminate economic,…

  16. Repeated-sprint ability and aerobic fitness.

    Science.gov (United States)

    Thébault, Nicolas; Léger, Luc A; Passelergue, Philippe

    2011-10-01

    The purpose of this study was to reinvestigate the relationship between aerobic fitness and fatigue indices of repeated-sprint ability (RSA), with special attention to methodological normalization. Soldiers were divided into low (n = 10) and high (n = 9) fitness groups according to a preset maximal aerobic speed (MAS) of 17 km·h(-1) (∼60 ml O2·kg(-1)·min) measured with the University of Montreal Track Test (UMTT). Subjects' assessment included the RSA test (3 sets of 5 40-m sprints with 1-minute rest between sprints and 1.5 minutes between sets), a 40-m sprint (criterion test used in the computation of fatigue indices for the RSA test), strength and power measurement of the lower limbs, and the 20-m shuttle run test (20-m SRT) and the UMTT, which are measures of maximal aerobic power. The highest correlation with the RSA fatigue indices was obtained with the 20-m SRT (r = 0.90, p = 0.0001, n = 19), a test with 180° direction changes and accelerations and decelerations. The lower correlation (r = 0.66, p tests better disclose the importance of aerobic fitness for RSA and that aerobic power is not the sole determinant of RSA. However, neither strength nor vertical jumping power was correlated to the RSA fatigue indices. Subjects with greater MAS were able to maintain almost constant level of speed throughout series of repeated sprints and achieved better recovery between series. A MAS of at least 17 km·h(-1) favors constant and high speed level during repeated sprints. From a practical point of view, a high aerobic fitness is a precious asset in counteracting fatigue in sports with numerous sprint repetitions.

  17. A Review of Spatial Ability Research

    Science.gov (United States)

    Mohler, James L.

    2008-01-01

    Spatial ability research has been approached from several psychological vantages since its beginnings in the late 1800s. This contribution attempts a summation of spatial ability research, beginning with a historical vignette and a major section on each psychological approach including the psychometric, developmental, differential and information…

  18. Functional Ability, Community Reintegration and Participation ...

    African Journals Online (AJOL)

    Results: Significantly positive correlations (p< 0.05) were found between functional ability and community reintegration (r = 0.54; p = 0.01) as well as between participation restriction and community reintegration (r = 0.34; p = 0.05). Individuals with left hemiplegia had significantly higher mean rank scores in functional ability ...

  19. Spatial Ability Learning through Educational Robotics

    Science.gov (United States)

    Julià, Carme; Antolí, Juan Òscar

    2016-01-01

    Several authors insist on the importance of students' acquisition of spatial abilities and visualization in order to have academic success in areas such as science, technology or engineering. This paper proposes to discuss and analyse the use of educational robotics to develop spatial abilities in 12 year old students. First of all, a course to…

  20. Reading Abilities and Strategies: A Short Introduction

    Science.gov (United States)

    Liu, Feng

    2010-01-01

    This paper gives a short analysis of reading abilities and reading strategies. Much research has been done to investigate the nature of reading, though it's had to exactly define reading abilities and strategies. Different kinds of readings are discussed in this paper and distinctions are made between first language reading and second or foreign…

  1. Cultural Studies, Pedagogy, and Response-Ability

    Science.gov (United States)

    Rossiter, Penelope

    2012-01-01

    A few years ago, in a tutorial in an advanced level undergraduate subject that she teaches--"Emotions, Culture and Community"--the author was a witness and participant in a pedagogical event that moved and provoked the class: It incited response-ability. This article is about that event, the meaning of response-ability, and the window…

  2. Mental Rotation Ability and Computer Game Experience

    Science.gov (United States)

    Gecu, Zeynep; Cagiltay, Kursat

    2015-01-01

    Computer games, which are currently very popular among students, can affect different cognitive abilities. The purpose of the present study is to examine undergraduate students' experiences and preferences in playing computer games as well as their mental rotation abilities. A total of 163 undergraduate students participated. The results showed a…

  3. Psycholinguistic Abilities of Children with Williams Syndrome

    Science.gov (United States)

    Rossi, Natalia F.; Heinze, Elena Garayzabal; Giacheti, Celia M.; Goncalves, Oscar F.; Sampaio, Adriana

    2012-01-01

    The objective of this study was to investigate the psycholinguistic abilities of children with Williams syndrome (WS) and typically developing children using the Illinois Test of Psycholinguistic Abilities (ITPA). Performance on the ITPA was analysed in a group with WS (N=20, mean age=8.5 years, SD=1.62) and two typically developing groups,…

  4. Does Classmate Ability Influence Students' Social Skills?

    Science.gov (United States)

    Gottfried, Michael A.

    2015-01-01

    Empirically, the link between classmate ability and individual-level student achievement has been established. And yet, within the scope of this body of literature, there is a dearth of studies examining if a relationship also persists between classmate ability and non-achievement outcomes--that is, social skills. This article fills this research…

  5. Carbon adaptation influence the antagonistic ability of ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... antagonistic ability of the adapted strains against Fom relative to the parental strains resulted from an altered ability to metabolize root exudates. Bacteria introduced into soil as agents for the biological control of plant pathogens must be capable of adaptation to a hostile environment in terms of both abiotic ...

  6. 45 CFR 1616.7 - Language ability.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Language ability. 1616.7 Section 1616.7 Public... § 1616.7 Language ability. In areas where a significant number of clients speak a language other than English as their principal language, a recipient shall adopt employment policies that insure that legal...

  7. Linguistic Ability: Some Myths and Some Evidence.

    Science.gov (United States)

    Robinson, Gail L.

    "Linguistic ability" is a widely misused term in foreign language literature. This confusion prompted an investigation into language aptitude testing, the specific goals of which included determining: the distribution of language aptitude across ability range; the validity of Pimsleur's suggestions of combined verbal and auditory scores;…

  8. Identifying Autism through Empathizing and Systemizing Abilities

    Directory of Open Access Journals (Sweden)

    Evi van der Zee

    2017-10-01

    Full Text Available Baron-Cohen’s Empathizing-Systemizing theory plays a central role in this study due to its success in interpreting the core impairments and strengths in autism. The theory states that low empathizing skills are responsible for the social difficulties in autism, and that high levels of systemizing are accountable for the restricted, repetitive patterns of behavior in autism. We therefore hypothesized that there is a significant discrepancy between a child’s empathizing and systemizing abilities when autism is present. We developed Dutch versions of the questionnaires that are associated with the theory: the Autism Quotient questionnaire, the Empathizing Quotient questionnaire and the Systemizing Quotient questionnaire. As hypothesized, the scores of children with autism on the Empathizing Quotient questionnaire and on the Systemizing Quotient questionnaire (EQ-SQ Child_NL show a significant difference. Furthermore, the EQ-SQ Child_NL predicts the score of children in general on the Dutch version of the Autism Quotient questionnaire (AQ Child_NL.

  9. Childhood cognitive ability accounts for associations between cognitive ability and brain cortical thickness in old age.

    Science.gov (United States)

    Karama, S; Bastin, M E; Murray, C; Royle, N A; Penke, L; Muñoz Maniega, S; Gow, A J; Corley, J; Valdés Hernández, M del C; Lewis, J D; Rousseau, M-É; Lepage, C; Fonov, V; Collins, D L; Booth, T; Rioux, P; Sherif, T; Adalat, R; Starr, J M; Evans, A C; Wardlaw, J M; Deary, I J

    2014-05-01

    Associations between brain cortical tissue volume and cognitive function in old age are frequently interpreted as suggesting that preservation of cortical tissue is the foundation of successful cognitive aging. However, this association could also, in part, reflect a lifelong association between cognitive ability and cortical tissue. We analyzed data on 588 subjects from the Lothian Birth Cohort 1936 who had intelligence quotient (IQ) scores from the same cognitive test available at both 11 and 70 years of age as well as high-resolution brain magnetic resonance imaging data obtained at approximately 73 years of age. Cortical thickness was estimated at 81 924 sampling points across the cortex for each subject using an automated pipeline. Multiple regression was used to assess associations between cortical thickness and the IQ measures at 11 and 70 years. Childhood IQ accounted for more than two-third of the association between IQ at 70 years and cortical thickness measured at age 73 years. This warns against ascribing a causal interpretation to the association between cognitive ability and cortical tissue in old age based on assumptions about, and exclusive reference to, the aging process and any associated disease. Without early-life measures of cognitive ability, it would have been tempting to conclude that preservation of cortical thickness in old age is a foundation for successful cognitive aging when, instead, it is a lifelong association. This being said, results should not be construed as meaning that all studies on aging require direct measures of childhood IQ, but as suggesting that proxy measures of prior cognitive function can be useful to take into consideration.

  10. Spatial Abilities during the Circalunar Cycle in Both Sexes

    Science.gov (United States)

    Ostatnikova, Daniela; Hodosy, Julius; Skoknova, Martina; Putz, Zdenek; Kudela, Matus; Celec, Peter

    2010-01-01

    Spatial abilities vary during the menstrual cycle. The effects of a similar rhythm in men are unknown. Mental rotation and spatial visualization of young healthy volunteers (29 females and 31 males) were tested during the menstrual and periovulatory phase of the menstrual cycle in women, and during the low-testosterone and high-testosterone phases…

  11. Effects of Mental Abilities on Obtained Intercorrelations among VPI Scales

    Science.gov (United States)

    Folsom, Cylde H., Jr.

    1973-01-01

    A samples of 347 secondary school students were administered Holland's Vocational Preference Inventory. They were divided into high and low mental ability groups, and correlations were computed between the VPI scores of subjects within each of the IQ ranges. The results suggest that the VPI's usefulness may be limited to secondary school students…

  12. 201 The Effects of Gender and Mathematics Ability on Academic ...

    African Journals Online (AJOL)

    User

    2011-07-21

    Jul 21, 2011 ... Males as naturally endowed have power and prestige thereby having higher and superior status than women (Umoh, 2003). This illustrates the high level of gender stereotype in education and the society at large. The Effects of Gender and Mathematics Ability on Academic Performance of Students.

  13. Maternal ability to take care of children exposed to HIV

    Directory of Open Access Journals (Sweden)

    Julyana Gomes Freitas

    2013-07-01

    Full Text Available OBJECTIVE: to assess the ability of mothers to take care of children exposed to HIV, using the Assessment Scale of Care Skills for Children Exposed to HIV at Birth and to check the association between the scale dimensions and maternal characteristics. METHOD: this cross-sectional study involved 62 HIV+ mothers whose children of up to one year old had been exposed to the virus at birth. The Assessment Scale of Care Skills for Children Exposed to HIV at Birth consists of 52 items and five dimensions, indicating high, moderate or low care ability. RESULTS: 72.7% of the mothers appropriately offered zidovudine syrup; 86.0% were highly skilled to prepare and administer milk formula; 44.4% were moderately able to prepare and administer complementary feeding; 76.5% revealed high ability to administer prophylactic treatment against pneumonia and 95.3% demonstrated high abilities for clinical monitoring and immunization. Significant associations were found between some maternal variables and the scale dimensions. CONCLUSION: the scale permits the assessment of maternal care delivery to these children and the accomplishment of specific child health interventions.

  14. Hetrosis and combining ability of sub tropical maize inbred lines ...

    African Journals Online (AJOL)

    The objective of this study was to determine the combining ability of subtropical maize inbred lines and identify appropriate germplasm for hybrid development. P6 was the highest yielding parent and P2 x P7 was the highest yielding cross. Heterosis for grain yield was high in those involving P6 as a parent. Parents P2, P7 ...

  15. Heterosis and combining ability for grain yield and yield component ...

    African Journals Online (AJOL)

    Combining ability analysis for grain yield and yield component traits in maize were carried out in 8×8 diallel cross. The analysis of variance showed there is highly significant variation between the genotypes for all the traits considered. Year of testing was significant only for days to maturity and grain yield per hectare.

  16. Combining ability for maize grain yield and other agronomic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Field experiments were conducted at the University of Ilorin Teaching and Research Farm in 2005 and. 2006 cropping seasons with the objective to evaluate the combining ability for maize grain yield and other agronomic characters in 10 open pollinated maize varieties, which have been selected for high.

  17. Interaction between motor ability and skill learning in children: Application of implicit and explicit approaches.

    Science.gov (United States)

    Maxwell, Jon P; Capio, Catherine M; Masters, Rich S W

    2017-05-01

    The benefits of implicit and explicit motor learning approaches in young adults have been studied extensively, but much less in children. This study investigated the relationship between fundamental motor ability and implicit/explicit learning in children using the errorless learning paradigm. First, the motor ability of 261 children (142 boys, 119 girls) aged 9-12 years (M = 9.74, SD = 0.67) was measured. Second, children with motor ability scores in the upper and lower quartile learned a golf-putting skill in either an errorless (implicit) or errorful (explicit) learning condition. Four groups were formed: Errorless High-Ability (n = 13), Errorless Low-Ability (n = 11), Errorful High-Ability (n = 10), and Errorful Low-Ability (n = 11). Learning consisted of 300 practice trials, while testing included a 50-trial retention test, followed by a 50-trial secondary task transfer test, and another 50-trial retention test. The results showed that for high- and low-ability errorless learners, motor performance was unaffected by the secondary task, as was the case for high-ability errorful learners. Low-ability errorful learners performed worse with a secondary task and were significantly poorer than the corresponding high-ability group. These results suggest that implicit motor learning (errorless) may be beneficial for children with low motor ability. The findings also show a trend that children of high motor ability might benefit from learning explicitly (errorful). Further research is recommended to examine the compatibility of implicit and explicit approaches for children of different abilities.

  18. Family Correlates of Verbal Reasoning Ability

    Science.gov (United States)

    Kellaghan, Thomas; MacNamara, John

    1972-01-01

    The relationship between verbal reasoning ability on the one hand and sex, social class, family size, and ordinal position in the family on the other were examined for a representative sample of 11-year-old Irish children. (Authors)

  19. Assessing functional ability in older patients

    DEFF Research Database (Denmark)

    Nielsen, Louise Møldrup; Maribo, Thomas; Nielsen, Hanne Grethe

    2014-01-01

    Aim: This study aimed to develop an understanding of how primary and secondary care health professionals perceive current practice and challenges in assessing older patients’ functional abilities. A secondary aim was to gain insight into how these professionals perceive the need for generic tools...... from the hospital expressed a need for a fast and simple screening tool to identify those in need of further rehabilitation and care after discharge. Participants from the municipality expressed a need for a more detailed assessment tool to capture information about patients’ ability to perform daily...... to administer, to assess the quality of functional ability and predict the need for rehabilitation. The different context (hospital or primary care) seems to influence the way health professionals perceive the need for assessment of functional ability in older patients....

  20. Ability to Consent to Parkinson Disease Research

    Science.gov (United States)

    ... part of a research study. This is a legal and ethical requirement. 2 PD can affect the ability to ... 1951, it is now a weekly with 48 issues per year. Copyright © 2013 American Academy of Neurology. All rights reserved. ...