bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and electrochemical characterization of LiMnPO4/single‐walled carbon nanotube composites as cathode material for Li‐ion battery
Authors: Dettlaff‐Weglikowska Urszula , Sato Norio , Yoshida Jun , Roth Siegmar 
Published: November 2009

AbstractWe investigated the synthesis of the nanocrystalline LiMnPO4 and its composites with single‐walled carbon nanotubes (SWNTs) in order to apply them as cathode material in Li‐ion battery. Two synthesis routes, precipitation and sol–gel, have been evaluated with regard to elemental composition, crystal size and crystal structure. Precipitation of LiMnPO4 from aqueous solution produces microcrystalline material with low specific surface area of 5 m2/g. Sol–gel procedure and in situ incorporation of SWNTs reduce the particle size to less than 100 nm and enhances specific surface area by factor of 10. Both materials have been used to prepare a cathode and the electrochemical performance of assembled battery has been tested. Whereas the electrical conductivity of the composite increases by 5 orders of magnitude upon addition of 1 wt.% of SWNTs, the battery capacity with a value of 20 mAh/g (theoretical 175 mAh/g) still appears low. We found out that incorporation of LiMnPO4 nanocrystals in a dense SWNT network (bucky paper) improves significantly the battery performance, and capacity approaching 150 mAh/g can be achieved. Our experiments provides the proof of principle that individual nanosize particles of LiMnPO4 can be sufficiently separated by conducting SWNTs to prevent their agglomeration, and electrically wired in a network for efficient electronic and ionic transport through the cathode.
Gas chromatography coupled to electron capture negative ion mass spectrometry with nitrogen as the reagent gas – an alternative method for the determination of polybrominated compounds
Authors: Rosenfelder Natalie , Vetter Walter 
Published: November 2009

AbstractGas chromatography in combination with electron capture negative ion mass spectrometry (GC/ECNI‐MS) is a sensitive method for the determination of polybrominated compounds in environmental and food samples via detection of the bromide ion isotopes m/z 79 and 81. The standard reagent gas for inducing chemical ionization in GC/ECNI‐MS is methane. However, the use of methane has some drawbacks as it promotes carbonization of the filament and ion source. In this study, we explored the suitability of nitrogen as reagent gas for the determination of brominated flame retardants (polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), allyl‐2,4,6‐tribromophenyl ether (ATE) and 2,3‐dibromopropyl‐2,4,6‐tribromophenyl ether (DPTE)) and halogenated natural products (for instance, methoxylated tetrabrominated diphenylethers and polybrominated hexahydroxanthene derivatives). An ion source temperature of 250°C and a nitrogen pressure of 7 Torr in the ion source gave the highest response for m/z 79 and 81 of virtually all investigated polybrominated compounds. Using these conditions, nitrogen‐mediated GC/ECNI‐MS usually gave higher sensitivity than the method with methane previously used in our lab. In addition, the ion source was not contaminated to the same degree and the lifetime of the filament was significantly increased. Moreover, the response factors of the different polybrominated compounds with the exception of 2,4,6‐tribromophenol were more uniform than with methane. Nitrogen is available at very high purity at relatively low price. Copyright © 2009 John Wiley & Sons, Ltd.
Re‐presenting the social construction of science in light of the propositions of Bruno Latour: For a renewal of the school conception of science in secondary schools
Authors: Richard Vincent , Bader Barbara 
Published: November 2009

AbstractCurrent opinion holds that school science has not been producing the expected outcomes. Highlighted by a considerable body of research, one of the concerns is that young people still mobilize a naive conception of science. Consequently, we must pursue the reflection process concerning ways of renewing the school conception of science so as to propose ways of representing and doing that are a greater source of participation among students. In this article, we argue for the importance of enriching school discourses by mobilizing a socialized conception of science. Our perspective seeks to highlight the major theoretical contributions of ethnomethodology put forward by Bruno Latour. Hence, we propose an operational definition of the social construction of science based on actor‐network theory as an attempt to produce a more focused conceptualization of science as a social enterprise. This theoretical work enables us to bring out various facets of the social construction of science that, in our view, should be accounted for in classes to renew the school image of science in line with the characteristics of contemporary technosciencesin the making. Finally, we illustrate how we can mobilize this understanding of science for secondary students. © 2009 Wiley Periodicals, Inc.Sci Ed94:743–759, 2010
Micro X‐ray diffraction and fluorescence tomography for the study of multilayered automotive paints
Authors: De Nolf Wout , Janssens Koen 
Published: November 2009

AbstractCombined microscopic X‐ray fluorescence/microscopic X‐ray diffraction (µ‐XRF/µ‐XRD) tomography is a recently developed method that allows the visualization of the distribution of chemical elements and the associated crystalline phases inside complex, heterogeneous materials of extended thickness (millimeter range) in a nondestructive fashion. In this paper, the accuracy and resolution with which the individual layers in a multilayer stack of automotive paints can be distinguished is evaluated, and some of their properties measured. A paint layer system of eight layers was investigated, in which eight different crystalline substances were identified, each layer consisting of an organic, synthetic resin doped with finely milled inorganic compounds that serve as pigments or to strengthen the layer. In the XRD tomograms, all paint layers could be straightforwardly distinguished and their average thickness calculated. In case the filtered back projection method was used for tomogram reconstruction, a spatial resolution comparable to the microbeam size was obtained indicating no significant reconstruction blurring. When a more robust reconstruction method, such as the maximum‐likelihood expectation maximization method, was employed, tomograms showing fewer artifacts were obtained, but with a spatial resolution that was two times worse. In the corresponding XRF tomograms, significant self‐absorption distorted the element‐specific tomograms corresponding to the low‐energy (<7 keV) characteristic radiation and limited their usefulness. It can be concluded that microbeam XRD tomography allows the accurate visualization of the distribution of crystalline phases in multilayered automotive paint materials of millimeter dimensions with sufficient resolution to allow separate characterization of each layer in terms of its crystal‐phase composition and thickness. Copyright © 2009 John Wiley & Sons, Ltd.
Optimal combination of estimating equations in the analysis of multilevel nested correlated data
Authors: Stoner J. A. , Leroux B. G. , Puumala M. 
Published: November 2009

AbstractMultilevel nested, correlated data often arise in biomedical research. Examples include teeth nested within quadrants in a mouth or students nested within classrooms in schools. In some settings, cluster sizes may be large relative to the number of independent clusters and the degree of correlation may vary across clusters. When cluster sizes are large, fitting marginal regression models using Generalized Estimating Equations with flexible correlation structures that reflect the nested structure may fail to converge and result in unstable covariance estimates. Also, the use of patterned, nested working correlation structures may not be efficient when correlation varies across clusters. This paper describes a flexible marginal regression modeling approach based on an optimal combination of estimating equations. Particular within‐cluster and between‐cluster data contrasts are used without specification of the working covariance structure and without estimation of covariance parameters. The method involves estimation of the covariance matrix only for the vector of component estimating equations (which is typically of small dimension) rather than the covariance matrix of the observations within a cluster (which may be of large dimension). In settings where the number of clusters is large relative to the cluster size, the method is stable and is highly efficient, while maintaining appropriate coverage levels. Performance of the method is investigated with simulation studies and an application to a periodontal study. Copyright © 2009 John Wiley & Sons, Ltd.
Voluntary agreements to improve environmental quality: symbolic and substantive cooperation
Authors: Delmas Magali A. , Montes‐Sancho Maria J. 
Published: November 2009

AbstractWithin the context of environmental voluntary agreements (VAs), this paper analyzes the determinants of the degree of participation by firms in collective corporate political strategies that aim to shape government policy. We demonstrate that substantive cooperative strategies are more likely to be pursued by firms that enter a VA close to its initiation, while symbolic cooperation is more likely behavior by late joiners. We show that late joiners and early joiners within VAs adopt different cooperative strategies because they face different institutional pressures. Our analysis is based on the strategies of firms participating in the Climate Challenge program (1995–2000) established by the U.S. Department of Energy and representatives of the national electric utilities to reduce greenhouse gas emissions. Our results show that early joiners were subjected to higher levels of political pressure at the state level and were more dependent on local and federal regulatory agencies than late joiners were. Early joiners were also better connected to the trade association and more visible. Late joiners had undertaken significantly less investment in environmental improvements than early joiners. Our paper also illustrates the difficulty involved in using VAs to try to induce improved environmental outcomes when there are no sanctioning mechanisms. Although early entrants reduced their emissions more than nonparticipants, our results show no significant difference overall between participants and nonparticipants in the reduction of their emissions. Copyright © 2010 John Wiley & Sons, Ltd.
Tunable Two‐Dimensional Binary Molecular Networks
Authors: Huang Yu Li , Chen Wei , Li Hui , Ma Jing , Pflaum Jens , Wee Andrew Thye Shen 
Published: November 2009

AbstractA novel approach to constructing tunable and robust 2D binary molecular nanostructures on an inert graphite surface is presented. The guest molecules are embedded into a host molecular matrix and constrained via the formation of multiple intermolecular hydrogen bonds. By varying the binary molecular ratio and the molecular geometry, various molecular arrays with tunable intermolecular distances are fabricated. The results suggest a promising route for the fabrication of ordered and stable molecular nanostructure arrays for molecular sensors, molecular spintronic devices, and molecular p–n nanojunctions.
Proteolytic Fluorescent Signal Amplification on Gold Nanoparticles for a Highly Sensitive and Rapid Protease Assay
Authors: Kim Joong H. , Chung Bong H. 
Published: November 2009

AbstractA new strategy for highly sensitive and rapid protease assay is developed by mediating proteolytic formation of oligonucleotide duplexes and using the duplexes for signal amplification. In the presence of matrix metalloprotease‐2 (MMP‐2), fragmentation of the intact DNA–peptide on gold nanoparticles (GNP) by hydrolytic cleavage of a peptide bond within the substrate allows diffusion of DNA away from the GNP and the formation of a DNA/RNA heteroduplex, leading to digestion of RNA by RNase H. Because of the high quenching efficacy of GNP to the fluorophore in RNA and multiple digestions of the RNA, the fluorescence signal recovery is amplified. This method permits the assessment of the activity of MMP‐2 at concentrations as low as 10 pMwithin 4 h. Compared with the reported protease nanosensors using quantum dots, GNP, and magnetic nanoparticles with the same peptide sequence, the assay time of this method is sixfold faster and the limit of detection is 100‐fold more sensitive. The formulations for proteolytic formations of oligonucleotides duplexes for signal amplification on GNP could lead to the development of more sensitive and rapid protease assay techniques, thus extending the role of proteases as therapeutic targets and disease indicators.
Rank methods
Authors: Wolfe Douglas A. 
Published: November 2009

AbstractOne of the major goals of statistics is to use data collected from a population to make inferences (hypothesis tests, confidence regions, and point estimators) about unknown attributes of the population. When there are good reasons to believe that the basic features of a population can be well approximated by a standard probability distribution, such as the commonly used Gaussian distribution, then a variety of approaches are available to construct procedures with optimal properties. When, however, a particular distribution is not an appropriate model for a population, the statistical procedures that are optimal for that distribution may not perform well; that is, model‐based statistical procedures may not be robust to departures from the assumed model. In such situations, one can use nonparametric procedures that maintain important stipulated properties (such as nominal significance level for hypothesis tests and coverage probability for confidence regions) over broad classes of probability distributions. While such nonparametric procedures are not optimal for a specific probability model, they are generally robust to deviations from that model. Many nonparametric procedures rely on simple counting and ranking processes applied either directly to the sample data or to some natural function of it and they are commonly known in the statistical literature as rank methods. In this article, we discuss the two basic approaches that lead to distribution‐free test procedures based on ranks and then illustrate how distribution‐free confidence intervals and robust point estimators can be derived directly from these hypothesis tests. Copyright © 2009 John Wiley & Sons, Inc.This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods
Notable Exceptions? New and Arrested Directions in Canadian Foreign Policy Literature
Authors: Black David R. , Smith Heather A. 
Published: November 2009

AbstractThe literature on Canadian Foreign Policy has often been characterized as overly descriptive and theoretically weak. This type of characterization, advanced most recently by Maureen Molot, is no longer wholly accurate. By reviewing several relatively recent contributions and debates in this literature, it is demonstrated that in pockets, the subfield has advanced substantially in theoretical sophistication. Nevertheless, it continues to manifest important gaps and limited cumulation. The article speculates on why this should be so, and on how the theoretical condition of the subfield can be advanced. Approaches which incorporate the interplay of internal and external influences on policy, which borrow from important developments in the wider fields of International Relations and Comparative Politics, and which engage in comparison across issue-areas, countries and time are advocated. Applications drawing on “historical materialist,” regime, and epistemic community literatures are specifically promoted.
A Marxist Theory of Justice?
Authors: Shandro A. M. 
Published: November 2009

AbstractSome recent Marxologists (notably Allen Buchanan, Richard Miller and Allen Wood) have denied that the idea of justice can play any significant role within Marxist thought. This article maintains, on the contrary, that the very logic of historical materialism, notably the concept of the historical development of human needs, necessitates a concept of justice even in the higher phase of communism. Furthermore, the “anti-juridical” interpretation of Marx fails to provide an adequate account of the connection between the communist values of self-realization and community. It therefore obscures the concerns addressed by a notion of justice. The early Marx's concept of species-being (Gattungswesen) expresses the relation between self-realization and community in historical terms. Thus it provides an appropriate context for a Marxist theory of justice.
Fichte'sRedenas a Model: Léon Dion's Addresses to the Quebec Nation
Authors: Laforest Guy 
Published: November 2009

AbstractLéon Dion is a pioneer of political science in Quebec and Canada. For over 25 years he has advocated a series of reforms of the Canadian federal system, striking a balance between his commitment to Quebec nationalism and his loyalty to Canada. This article analyzes Léon Dion's use of German thought in his latest book, underlying his effort to thwart the apathy and moroseness descending upon Quebec politics in the post-referendum era. A parallel will be drawn between Dion's book and Fichte'sAddresses to the German Nation, delivered in Berlin in the winter of 1807. Both thinkers are characterized by intellectual involvement and concern for national identity in times of crisis. It will be argued that Dion's book contains an important political message for English-speaking Canada.
Selecting Policy Instruments: Neo-Institutional and Rational Choice Interpretations of Automobile Insurance in Ontario
Authors: Atkinson Michael M. , Nigol Robert A. 
Published: November 2009

AbstractThe rational choice model of politics, which construes important political processes as a series of choices taken by self-interested political actors, has dominated theorizing on the subject of policy instruments in Canada. While useful, this approach is nonetheless limited by its narrow conception of rationality and its inattention to the context of instrument choice. As an alternative, the neo-institutional approach offers a perspective on political choice that takes better account of contextual and organizational factors. In this article, the logic of both approaches is used to explain the policy process in the case of automobile insurance in Ontario. The purpose of this exercise is exploratory, not confirmatory. Both approaches do, in fact, offer plausible explanations for the creation of a rate review board, the retention of fault-liability as the basis of compensation and the apparent rejection of public automobile insurance. However, the study concludes that it is essential that research strategies in the realm of instrument choice incorporate insights from the neo-institutional approach.
Paradigms and Political Discourse: Protective Legislation in France and the United States Before 1914
Authors: Jenson Jane 
Published: November 2009

AbstractThis article examines the differences in pre-1914 France and the United States in two kinds of state policies regulating women's behaviour, those “protecting” the condition under which women participated in certain occupations and those providing infant and maternal protection. Those policies are examined to illuminate the argument that politics, including state policies, makes an important contribution to the maintenance and change of ongoing systems of social relations. Central to this argument is the notion that meaning systems around which actors constitute collective identities are a crucial analytic focus for understanding stability and change. At the end of the nineteenth century hegemonic societal paradigms, constructed out of the processes institutionalizing new social relations, emerged in France and the US. The French paradigm of “citizen-producer” and the American one of “specialized citizenship” had quite different implications for the patterns of gender relations embedded within them. These implications are visible in the treatment of women's work and maternity in these years of the emerging welfare state.
La question de l'appartenance: Montesquieu, Rousseau et la Révolution française
Authors: Knee Philip 
Published: November 2009

AbstractThe paradox of modern political theory which affirms individual autonomy and simultaneously seeks solid foundations for social belonging is approached here through its emergence in eighteenth-century France: first by a comparative reading of Montesquieu and Rousseau according to the exigencies of suitability and legitimacy of their respective political philosophies; then by an evocation of some of the echoes of their thought in the French Revolution around the themes of the exercise of power, of virtue and of religion.
Support for the Canadian Federal Progressive Conservative Party since 1988: The Impact of Economic Evaluations and Economic Issues
Authors: Clarke Harold D. , Kornberg Allan 
Published: November 2009

AbstractSince their victory in the dramatic 1988 Canadian federal election, the governing Progressive Conservatives have suffered a rapid and precipitous decline in public support. Observers have attributed the massive erosion in popularity to the failure of the Meech Lake Accord, the government's insistence on implementing the highly unpopular value-added Goods and Services Tax (GST) and increasing public reservations about the wisdom of the free trade agreement. This article contends that, while these arguments have merit, a more important factor is that many Canadians blame the federal government for the poor state of the national economy and adverse personal economic circumstances. Moreover, negative reactions to the two highly salient economic issues, free trade and the GST, are, in part at least, products of public disapproval of the government's economic performance. The analyses are based on data gathered in national cross-sectional and panel surveys conducted over the 1983–1990 period.
Quand les femmes se distinguent: féminisme et représentation politique au Québec
Authors: Tremblay Manon 
Published: November 2009

AbstractThis article examines how Quebec politicians' sex and political party influence the orientation of their opinions through three themes: the evolution of women's social status, actions of the feminist movement in this sense and the idea of female legislators representing women. A questionnaire was sent to the 305 candidates of the New Democratic party of Quebec, the Quebec Liberal party and the Parti québécois in the provincial election of September 25, 1989. The results show that if women and men manifest no differences in their support of the evolution of women's social status and of the feminist movement, women are more inclined than men to support the idea that women politicians should represent the specific interests of women. Of all the above-mentioned parties, the Liberal party resists this idea the most as well as the feminist movement in general.