bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring the Influence of Chemical Composition of Electrical and Dielectric Properties of Special Glasses
Authors: Psota Jozef , Bošák Ondrej , Labaš Vladimír , Tóth Martin 
Published: September 2011

Monitoring the Influence of Chemical Composition of Electrical and Dielectric Properties of Special Glasses
The paper deals with the results of experimentally determined influence of the chemical composition change of pure Ge-Se-Te glasses systems with the rare earths elements additions (Pr, Er and Ho in oxide or pure metal form) on electrical and dielectric properties of the glasses. We used chalcogenide bulk glasses Ge20Se80-xTex for x ∈ (0, 5, 10, 15) prepared by systematic replacement of Se by Te. We wanted to find how electrical and dielectric properties of chosen chalcogenide glasses change with the change of content and form of rare earths. We carried out the measurements at different temperatures from 20 °C to 170 °C. Results show that the inhomogeneity and defects in the measured glasses have had an impact on the measured dielectric parameters.
Flexibility in Higher Education: Revisiting Expectations
Authors: Collis Betty , Moonen Jef 
Published: September 2011

We have studied the construct of flexibility in higher education for many years, as researchers and practitioners. In this context we define flexibility as offering the student choices in how, what, where, when and with whom he or she participates in learning-related activities while enrolled in a higher education institution. In a textbook we wrote on the topic in 2001 we identified options that could be available to students in higher education to increase the flexibility of their participation. We studied these from the perspective not only of the student but also in terms of their implications for instructors and for higher-education institutions and examined the key roles that pedagogical change and technology play in increasing flexibility. Now is it nearly a decade later. We will revisit key issues relating to flexibility in higher education, identify in broad terms the extent to which increased flexibility has become established, is still developing, or has developed in ways we did not anticipate directly a decade earlier. We will also review our scenarios for change in higher education related to flexibility and contrast these with a more-recent set from the UK. Our major conclusion is that flexibility is still as pertinent a theme for higher education in 2011 as it was in 2001.
Llevamos bastantes años estudiando la construcción de la flexibilidad en la educación superior, tanto desde la óptica de la investigación como de la práctica. Entendemos por flexibilidad la opción de ofrecer a los estudiantes la posibilidad de elegir cómo, qué, dónde, cuándo y con quién participan en las actividades de aprendizaje mientras están en una institución de educación superior. En el libro que escribimos sobre esta temática en 2001 identificamos opciones posibles para los estudiantes de educación superior con la finalidad de incrementar la flexibilidad de su participación. Lo estudiamos no solo desde la perspectiva del estudiante sino también desde las implicaciones para los profesores y para las instituciones de educación superior, y examinamos el papel fundamental que desempeñan el cambio pedagógico y la tecnología en el aumento de la flexibilidad. Ahora, diez años después, revisamos los temas clave relacionados con la flexibilidad en la educación superior e identificamos, en términos generales, hasta qué punto se ha ido estableciendo el incremento de la flexibilidad, si todavía está evolucionando o si ha evolucionado de una forma que no pudimos prever hace diez años. Revisamos también nuestros escenarios para el cambio en la educación superior relacionados con la flexibilidad y los contrastamos con un estudio más reciente llevado a cabo en el Reino Unido. Nuestra conclusión principal es que la cuestión de la flexibilidad en la educación superior sigue siendo tan pertinente en 2010 como lo era en 2001.
Learning Networks, Networked Learning
Authors: Sloep Peter , Berlanga Adriana 
Published: September 2011

Learning Networks are on-line social networks through which users share knowledge with each other and jointly develop new knowledge. This way, Learning Networks may enrich the experience of formal, school-based learning and form a viable setting for professional development. Although networked learning enjoys an increasing interest, many questions remain on how exactly learning in such networked contexts can contribute to successful education and training. Put differently, how should networked learning be designed best to facilitate education and training? Taking this as its point of departure, the chapter addresses such issues as the dynamic evolution of Learning Networks, trust formation and profiling in Learning Networks, and peer-support among Learning Network participants. This discussion will be interspersed with implementation guidelines for Learning Networks and with a discussion of the more extended case of a Learning Network for Higher Education. Taking into consideration research currently carried out at our own centre and elsewhere, the chapter will close off with a look into the future of Learning Networks.Las redes de aprendizaje (Learning Networks) son redes sociales en línea mediante las cuales los participantes comparten información y colaboran para crear conocimiento. De esta manera, estas redes enriquecen la experiencia de aprendizaje en cualquier contexto de aprendizaje, ya sea de educación formal (en escuelas o universidades) o educación no-formal (formación profesional). Aunque el concepto de aprendizaje en red suscita el interés de diferentes actores del ámbito educativo, aún existen muchos interrogantes sobre cómo debe diseñarse el aprendizaje en red para facilitar adecuadamente la educación y la formación. El artículo toma este interrogante como punto de partida, y posteriormente aborda cuestiones como la dinámica de la evolución de las redes de aprendizaje, la importancia de fomentar la confianza entre los participantes y el papel central que desempeña el perfil de usuario en la construcción de la confianza, así como el apoyo entre compañeros. Además, se elabora el proceso de diseño de una red de aprendizaje, y se describe un ejemplo en el contexto universitario. Basándonos en la investigación que actualmente se lleva a cabo en nuestro propio centro y en otros lugares, el capítulo concluye con una visión del futuro de las redes de aprendizaje.
The Cyber Media in Latin America and Web 2.0
Authors: Said-Hung Elias , Arcila-Calderón Carlos 
Published: September 2011

Technologies 2.0 are changing the spaces dedicated to interaction and participation in cyber media. The goal of this research is to determine the adoption of cyber journalism features and web 2.0 in media in Latin America. To achieve this objective this paper analyses 19 digital media in the region, based on two studies held in 2010 and framed on the project «Cyber media in Colombia and Latin America», which is supported by the Universidad del Norte (Colombia) and recently by the Universidad de los Andes (Venezuela). The study uses the method proposed by Rodríguez-Martínez, Codina & Pedraza-Jiménez (2010), which has been tested in previous research by the authors of this paper. According to the results, a good part of digital media in Latin America are incorporating web 2.0 tools, but there still exists notable quality differences in the ranking proposed between the best rated media (Colombia and Mexico) and the worst rated (Chile and Bolivia). This ranking allows, for example, to clearly identify how digital media in Latin America have important weaknesses in their general indicators, like accessibility mistakes, popularity and visibility levels; and in their specific indicators, in special those related to available resources for information deepening and interaction tools. As authors state in the article, showing these evidences of inequality can orientate future plans of Latin-American cyber media, especially if indicators related to users’ active participation are considered.
Las tecnologías 2.0 están transformando los espacios destinados a la interacción y la participación en los cibermedios. El objetivo de esta investigación es determinar el grado de adopción del ciberperiodismo y de las web 2.0 en América Latina. Para ello se analizaron 19 medios digitales de la región, a partir de los resultados obtenidos de dos olas de recopilación de datos llevados a cabo durante 2010, en el marco del proyecto «Los cibermedios en Colombia y América Latina», realizado desde la Universidad del Norte (Colombia), con el apoyo de la Universidad de los Andes (Venezuela). El estudio parte del modelo de análisis propuesto por Rodríguez-Martínez, Codina & Pedraza- Jiménez (2010). Los resultados apuntan que los medios latinoamericanos están apostando por la incorporación de herramientas de la web 2.0, pero que sin embargo existen notables diferencias de calidad entre los medios mejor calificados por el «ranking» del estudio (Colombia y México) y los peor valorados (Chile y Bolivia). Este «ranking» permitió, por ejemplo, identificar claramente cómo los medios digitales analizados en América Latina, aún siguen perdiendo importantes puntos en lo que se refiere a los aspectos relacionados con los indicadores generales, como por ejemplo los errores de accesibilidad, los niveles de popularidad y visibilidad de sus portales; y los indicadores específicos internos, en especial en lo que respecta a los recursos puestos a disposición para la profundización de la información y las herramientas de interacción.
On the Simple Inductive Limits of Splitting Interval Algebras with Dimension Drops
Authors: Li Zhiqiang 
Published: September 2011

Abstract A K-theoretic classification is given of the simple inductive limits of finite direct sums of the type I C*-algebras known as splitting interval algebras with di- mension drops. (These are the subhomogeneous C*-algebras, each having spectrum a finite union of points and an open interval, and torsion K1-group.)
Monodromy Filtrations and the Topology of Tropical Varieties
Authors: Helm David , Katz Eric 
Published: September 2011

AbstractWe study the topology of tropical varieties that arise from a certain natural class of varieties. We use the theory of tropical degenerations to construct a natural, “multiplicity-free” parameterization of Trop(X) by a topological space ГXand give a geometric interpretation of the cohomology of ГXin terms of the action of a monodromy operator on the cohomology ofX. This gives bounds on the Betti numbers of ГXin terms of the Betti numbers ofXwhich constrain the topology of Trop(X). We also obtain a description of the top power of the monodromy operator acting on middle cohomology ofXin terms of the volume pairing on ГX.
Role of Asphaltenes in Inhibiting Corrosion and Altering the Wettability of the Steel Surface
Authors: Ajmera P. , Robbins W. , Richter S. , Nešić S. 
Published: September 2011

Abstract
Asphaltenes (heptane insolubles) from a variety of crude oils have been identified previously as contributors to inhibition of internal corrosion of mild steel pipelines. However, the mechanism of inhibition is unknown. To explore the mechanism, carbon dioxide (CO2) corrosion rates and wettability (oil/water contact angles) have been measured using Arab Heavy crude oil and its asphaltenes. Inhibition of CO2 corrosion rates for carbon steel was measured using electrochemical methods in a glass cell; wettability was assessed using contact angle measurements in a multiphase goniometer. The phase behavior of asphaltenes in corrosion and wetting was evaluated in the crude, toluene (C7H8), or heptol (70:30 mixture of heptane [C7H16] and toluene). Inhibition on steel exposed to a hydrocarbon phase increased with the concentration of asphaltenes in toluene. Inhibition by asphaltenes dissolved in toluene appears to be more effective than in the whole crude, at equivalent concentrations of asphaltenes. At 5 wt% in toluene, asphaltenes form a strong protective layer on the carbon steel surface, which reduces the corrosion rate and makes the surface hydrophobic. When the solubility of the oil is altered to the point where asphaltenes start to flocculate, it enhances the corrosion inhibition greatly. However, the inhibition is not as persistent as for the fully dissolved asphaltenes, and the surface needs to be periodically wetted with the oil phase to maintain the protection.
The Odd–Even Effect in Sudoku Puzzles: Effects of Working Memory, Aging, and Experience
Authors: Chang Hye-Sang , Gibson Janet M. 
Published: September 2011

Abstract
The odd–even effect in numerical processing has been explained as the easier processing of even numbers compared with odd numbers. We investigated this effect in Sudoku puzzles, a reasoning problem that uses numbers but does not require arithmetic operations. Specifically, we asked whether the odd–even effect occurred with Sudoku puzzles and whether individual differences in working memory (WM), aging, and experience with Sudoku modulated this effect. We manipulated the presence of odd and even numbers in Sudoku puzzles, measured WM with the Wisconsin Card Sorting Test and backward digit span task, tested older and younger adults, and collected Sudoku experience frequency. Performance on Sudoku was more accurate for even puzzles than odd ones. Younger, experienced, and higher-WM participants were more accurate on Sudoku, but these individual difference variables did not interact with the odd–even effect. Odd numbers may impose more cognitive load than even numbers, but future research is needed to examine how age, experience, or WM may influence the odd–even effect.
Cell death‐inducing DFF45‐like effector b (Cideb) is present in pancreatic beta‐cells and involved in palmitate induced beta‐cell apoptosis
Authors: Li H. , Song Y. , Zhang L. J. , Li F. F. , Gu Y. , Zhang J. , Dong W. P. , Xue L. , Zhang L. Y. , Liu F. , Wang J. , Jiang L. N. , Ye J. , Li Q. 
Published: September 2011

AbstractBackgroundExcessive accumulation of long‐chain fatty acids in the pancreatic islets is associated with beta cell dysfunction and ultimately contributes to the pathogenesis of type 2 diabetes. It has been well proved that the cell death‐inducing DFF45‐like effector b (Cideb) is involved in cell apoptosis and lipid metabolism. However, the expression and function of Cideb in endocrine pancreas remain to be investigated.MethodsBy using reverse transcript polymerase chain reaction, immunohistochemistry and Western blot, we observed the expression of Cideb in pancreas tissues and clonal beta‐cell lines. The physiological role of Cideb was examined under the free fatty acid (FFA) administration and Cideb ribonucleic acid interference, and further analysis on apoptosis was measured by terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick end labelling assay and caspase‐3 activity. Nile red staining and quantitative evaluation of triglyceride were used to detect the lipid accumulation. The changes in esterification of FFA were traced by radiolabelled palmitate.ResultsCideb was abundantly expressed in pancreas and mainly localized in beta cells. FFAs, especially palmitate, induced an obvious increase of Cideb expression in beta cell lines. Adenoviral‐mediated overexpression of Cideb increased the apoptosis, whereas ribonucleic acid interference‐based Cideb depletion in beta‐TC3 cells had no effect on apoptosis in normal condition. Palmitate supplementation led to beta cell lipoapoptosis, and Cideb silencing exacerbated the apoptosis induced by palmitate, reduced intracellular triglyceride content and aggravated FFA overload in beta cells.ConclusionsThe present results suggest that increased Cideb expression upon palmitate exposure may be involved in beta cell lipoapoptosis through its influence on conversion of FFAs to lipid esters in lipid droplets. Copyright © 2011 John Wiley & Sons, Ltd.
Laser microstructuring of photomodified fluorinated ethylene propylene surface for confined growth of Chinese hamster ovary cells and single cell isolation
Authors: Yakunin S. , Fahrner M. , Reisinger B. , Itani H. , Romanin C. , Heitz J. 
Published: September 2011

AbstractWe present a method for laser lithography of cell‐adhesive arrays on a fluoropolymer surface. The method is based on 172 nm excimer‐lamp photomodification in ammonia atmosphere followed by microstructuring by laser ablation. The improved wettability of the polymer is caused by new chemical groups on the surface after the UV treatment that we proved by Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy analyses. The cell adhesion properties of micropatterned structures were tested by cultivation of mammalian cells. We show that single elongated cells can grow confined to lines with sharply defined boundaries of the cell‐covered areas. In preliminary experiments, we also demonstrate that the described technique allows the production of single‐cell arrays with variable cell shape. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Quasihybrid scheme of nonuniform rational B‐spline–uniform geometrical theory of diffraction method for radiation of antennas
Authors: Wang Nan , Dang Xiaojie , Yuan Haobo , Liang Changhong 
Published: September 2011

AbstractThe nonuniform rational B‐spline–uniform geometrical theory of diffraction (NURBS‐UTD) method is studied in this paper. To deal with arbitrary wire antennas without analytical directional functions, a quasihybrid scheme is presented to discuss the radiation pattern of wire antennas mounted around electrically large targets. The NURBS technique is introduced to construct targets, the wire antennas, and electrically large targets are analyzed by method of moment (MoM) and NURBS‐UTD, respectively. Information from results of ray tracing is chosen as interface between MoM and NURBS‐UTD to form quasihybrid scheme. The practicability and validity can be seen from examples given. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2963–2967, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26374
A simple and an accurate method for measuring the phase‐frequency response of fiber fabry‐perot tunable filter
Authors: Qi Haibing , Wei Shuhua , Yu Yonglin 
Published: September 2011

AbstractA simple and an accurate method for measuring the phase‐frequency response of fiber Fabry‐Perot (FFP) tunable filter driven by piezoelectric (PZT) is proposed and demonstrated.Considering the phase shift factor θ(f) induced by PZT in the transfer function of the filter, the derived equation shows a method to perform the phase‐frequency response of the filter by measuring the time delay between the maximum point of the input electrical signal and the local minimum point of the optical output signal. In this article the measured phase differences of a FFP tunable filter range from −0.4 to −220° with frequency from 40 Hz to 30 kHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2960–2963, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26375
Ultra‐wideband bandpass filters with a controllable and highly selective notch‐band
Authors: Zhou Liang , Liu Shao‐bin , Kong Xiang‐kun , Zhang Hai‐feng , Guo Ya‐nan 
Published: September 2011

AbstractIn this letter, a novel band‐notched ultra‐wideband (UWB) bandpass filter (BPF) is investigated. A structure of complementary two turns spiral resonator (CSR2) is proposed to improve notch performance of the UWB BPF. The single CSR2 unit cell has a size of 0.08λg × 0.08λg(what is λg) at stop‐band center frequency (5.7 GHz). With respect to the resonance nature of the miniaturization and high Q value, a compact UWB BPF with multiple CSR2s is designed. The proposed filter demonstrates band‐stop‐filter‐like response with high frequency selectivity and controllable bandwidth at rejection band. We assess the filtering behavior of structures from two aspects: the return loss and the group delay. The measured notched band frequency is range from 5.05 to 5.85 GHz(|S11|<−10dB). The maximum attenuation is more than 28 dB at the central frequency of 5.37 GHz. The measured and simulated results are well‐complied with each other. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2920–2922, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26376
Wwan/lte printed loop tablet computer antenna and its body sar analysis
Authors: Wong Kin‐Lu , Wei Wan‐Jhu , Chou Liang‐Che 
Published: September 2011

AbstractA WWAN/LTE printed loop antenna for tablet computer application is presented.The printed loop antenna is a half‐wavelength loop strip coupled‐fed by a patch monopole, which performs not only as a coupling feed but also as an efficient radiator for the antenna. By embedding a printed distributed inductor in the loop strip, dual‐resonance excitation of the half‐wavelength mode of the coupled‐fed loop antenna is obtained, which forms the antenna's lower band at about 800 MHz to cover the LTE700/GSM850/900 operation (704–960 MHz). The antenna's upper band is formed by both the resonant modes contributed by the patch monopole and the higher order resonant modes contributed by the loop strip. The upper band shows a large bandwidth (>1 GHz) to cover the GSM1800/1900/UMTS/LTE2300/2500 operation (1710–2690 MHz). Further, with a planar and compact structure (12 × 75 mm2), the antenna is suitable to be disposed in the limited space inside the tablet computer and meets the body specific absorption rate (SAR) requirement (<1.6 W/kg for 1‐g body tissue) for practical applications. Details of the proposed antenna and its body SAR results are presented. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2912–2919, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26377
Investigation of an ultra‐wideband microstrip antenna using finite elementary lines approach
Authors: Senouci S. , Zerguerras A. , Tao J. , Vuong T. H. 
Published: September 2011

AbstractThis work presents an investigation, using the approach of finite elementary lines (FEL), of an ultra‐wideband antenna. Two ways for expanding frequency band were combined: the electromagnetic coupling and the insertion of an air layer. A prototype of this antenna has been realized. A comparison between the antenna performance predicted by our approach and those provided by the high‐frequency simulation structure (HFSS) software and those measured is presented. An impedance bandwidth of about 50% and directivity at the first resonance of about 9 dB were achieved. A satisfactory concordance between results of our approach and measures is observed. The novelty of this work lies in the treatment by the FEL method, for the first time, of singularities induced by the gap of coupling and the jump of width. The computing time consumed by the FEL approach is about 10 times less than that consumed by the HFSS software to analyze the same structure on the same number of point's frequency domain, the latter being 68 min. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2978–2985, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26379