bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comment devient-on dirigeante d'une association sportive locale ? Des processus de transmission à l'œuvre en lien avec les rapports sociaux de sexe
Authors: Tatu-Colasseau Anne , Vieille Marchiset Gilles 
Published: December 2010

Résumé L’article a pour but l’élaboration d’une typologie de dirigeantes dans l’administration du sport local afin de rendre intelligible la diversité rencontrée et de produire un outil de comparaison synchronique et diachronique pour des recherches sur la même thématique. En nous appuyant sur une enquête régionale qualitative – entretiens collectifs et seize récits de vie –, nous restituons et interprétons les traits de quatre profils types de dirigeante en nous arrêtant particulièrement sur les rapports sociaux de sexe et les processus de transmission qui les façonnent : la dirigeante de circonstance, l’élue, la militante associative et la passionnée d’une discipline sportive. Chacune révèle un positionnement différencié dans la division sexuelle du travail opérante au sein de la direction sportive. Les différents profils suggèrent que la position des dirigeantes dépend des valeurs, des normes et des savoirs transmis dans différents contextes familiaux, professionnels et sportifs. Si les deux premiers profils confirment une forme de reproduction de l’ordre social masculin, les deux autres témoignent de transformation des effets de genre et de leur traduction en matière d’investissement féminin. Ils suggèrent des changements minoritaires mais en devenir dans la direction sportive.
Study to Investigate Learning Motivation Factors within Formal and Informal Learning Environments and their influence upon Web-Based Learning
Authors: Riaz Sadia , Rambli Dayang Rohaya , Salleh Rohani , Mushtaq Arif 
Published: December 2010

Learning is a cognitive process that occurs either
in a formal or informal learning environment, by way of
adopting either formal or informal learning process. While
the significance of former has been widely accepted, later is
still researched and lacks relevant studies on its implications
for web-based learning, especially by way of instigating
learning motivation. This paper presents descriptive analysis
of learning motivation factors within (i) formal and informal
learning environments, and (ii) formal and informal
learning processes, and then examines their influence on
web-based learning by computing Pearson correlations. To
achieve study objectives, the paper discusses relevant literature
and then conceptualizes a research model to be tested
through a survey based questionnaire. Formal learning
process is discussed with reference to learning activities as
promoted by formal learning institutes, while informal
learning process is examined by way of investigating learning
motivation factors associated with (i) video-games, (ii)
social networking websites and (iii) motion-pictures. Results
illustrate interesting revelation of learning motivational
factors, particularly motivational factors associated with
informal learning environment and processes have been
found to have a statistically significant relationship with
web-based learning. The paper concludes implications of the
statistical findings for designing of cognitively engaging
web-based learning environments.
Concomitant Chemoradiation in Locally Advanced Laryngeal Cancer
Authors: Jamshed Arif , Hussain Raza , Jamshed Sarah , Syed Aamir Ali , Loya Asif , Shah Mazhar Ali , Majeed Uzma , Hameed Shahid 
Published: December 2010

AbstractIntroductionDespite the acceptance of concomitant chemoradiation (CRT) as an alternative to total laryngectomy (TL) in locally advanced laryngeal cancer (LALC), laryngeal preservation is sparingly recommended in developing countries. We report on prognostic factors and survival in T3/T4 laryngeal cancer treated with concomitant CRT at Shaukat Khanum Memorial Cancer Hospital and Research Center (SKMCH and RC) to provide comparison with other geographic locations.Material and MethodsDuring the period November 2003-April 2009, 101 patients with biopsy proven untreated LALC underwent concurrent CRT treatment at SKMCH and RC. According to AJCC staging system (6th edition) 41 had T3 and 60 patients had T4 disease. Radiation dose to the larynx was 70 Gy in 35 fractions with concomitant cisplatin. Induction chemotherapy was given to 42 patients. Thirty-one patients required tracheotomy either before or during concomitant CRT.ResultsActuarial overall survival and laryngectomy free survival (LFS) for the whole group at 5 years were 54% (95% CI; 48-60) and 47% (95% CI; 42-52) respectively. Median LFS was 4.17 years. On univariate analysis patients with T4 tumors (p = 0.04), positive neck nodal disease (p = 0.02), supraglottic site (p = 0.02) and tracheotomy (0.009) had a significantly inferior LFS. Multivariate analysis showed tracheotomy to be the only factor significantly (p = 0.03) related to a higher risk of failure for LFS.ConclusionSurvival rates for LALC treated with concomitant CRT in our institution are acceptable. Our study supports the use of TL in patients with compromised airways that require tracheotomy as outcome with concomitant CRT is poor.
Cancrum Oris-associated with Acute Myeloid Leukemia: A Forgotten Disease
Authors: Krishnamurthy Arvind , Sundersingh Shirley , Srinivas Satish , Vaidhyanathan Anita , LNU Krishnarathinam 
Published: December 2010

AbstractCancrum oris is an orofacial gangrene, which during its fulminating course causes, progressive and mutilating destruction of the infected tissues with a consortium of microorganisms. This condition is considered to represent the “face of poverty” because factors connected with poverty, such as chronic malnutrition, poor oral hygiene and sanitation, faecal contamination, and exposure to viral and bacterial infections in an immunosupressed host contribute to disease progression. This condition is seen almost exclusively among the young children and carries a high mortality rate.We present a case of cancrum oris in a 45 years old lady being treated for acute myeloid leukemia with chemotherapy, who in addition to a polymicrobial bacterial infection had superinfection with Mucormycosis.
Aligning Short Sequencing Reads with Bowtie
Authors: Langmead Ben 
Published: December 2010

AbstractThis unit shows how to use the Bowtie package to align short sequencing reads, such as those output by second‐generation sequencing instruments. It also includes protocols for building a genome index and calling consensus sequences from Bowtie alignments using SAMtools. Curr. Protoc. Bioinform. 32:11.7.1‐11.7.14. © 2010 by John Wiley & Sons, Inc.
The components of an electrochemical cell
Authors: Hamnett A. 
Published: December 2010

AbstractElectrochemical cells are formed when two electronically conductingelectrodesare placed in an ionically conducting medium, theelectrolyte. When current is passed through the cell, electrochemicalreactionstake place at each electrode, leading to nett chemical conversion of one or more constituents of the cell into new materials. This chapter reviews the nature of the chemical reactions in simple cells, distinguishes between electrolysis and galvanic cell operation, describes the structure and dynamical behavior of the electrolyte, and reviews the properties of some special electrolytes of relevance to fuel cells: ionically conducting membranes, solid ionic conductors and molten salts.
History of high temperature fuel cell development
Authors: Yokokawa H. , Sakai N. 
Published: December 2010

AbstractThe historical overview of high temperature fuel cells, namely, the molten carbonate fuel cell (MCFC) and the solid oxide fuel cell (SOFC), is attempted from the viewpoint of materials development and conversion efficiency. The similarity in materials issues between MCFCs and SOFCs is described with emphasis on the importance of stability properties and mass transfer driven from the gradients of thermodynamic quantities, such as oxygen potential, electrical potential and temperature. The development of MCFCs is described to see how the disadvantages of using molten carbonates can be overcome without losing the advantages of using a liquid electrolyte. Corrosion and shorting due to cathode dissolution limit the life and cell performance. To improve these disadvantages, optimization will be required by full understanding of the interactions of materials with molten carbonates. The development of SOFCs is discussed from the viewpoint of overcoming the mechanical weaknesses caused by the volume changes associated with thermal cycles or atmospheric changes. This weak point makes it necessary to develop cell materials, a processing technique and stack design, simultaneously. The sealless tubular stacks and the planar ones with oxide interconnects are examples of success in establishing these technologies. Against the earlier expectation that SOFCs would suffer from poor material selection and lower efficiency, these SOFC systems have demonstrated that excellent long‐term stability has been achieved at high conversion efficiency without degradation. The second generation SOFC stacks with metal interconnects exhibit similar features to the MCFC stacks development, although the corrosion rate is less severe.
Solid oxide fuel cells (
SOFC
)
Authors: Holtappels P. , Stimming U. 
Published: December 2010

Abstract
Solid oxide fuel cells are fuel cells that operate in a temperature region between 650 °C and 1000 °C by using an oxygen ion conductor as the electrolyte. The ionic transported species are oxygen ions that allow the use of both hydrogen and carbon monoxide as well as directly applied methane as fuels while the oxidant is oxygen provided by air. The state‐of‐the art SOFC consists of an yttria‐stabilized zirconia (YSZ) as the electrolyte, a ceramic metallic composite, a Ni‐YSZ cermet as the fuel electrode and a ceramic composite of strontium doped lanthanum manganite and YSZ as the air electrode. The SOFC is, therefore, an all‐solid state system for which different designs may apply.
Both tubular and planar concepts of SOFC cells and stacks have been developed since the 1960s. The best developed SOFC system is the tubular cell design from Westinghouse (now Siemens Westinghouse Power Corporation), operating at temperatures around 1000 °C. Planar cell designs which allow operating temperatures between 650 °C and 850 °C by using an anode supported electrolyte are under development. The two different concepts, the tubular and the planar design are described in detail and the impact of the supporting component upon important aspects as operating conditions, power density, sealing and contacting are addressed.
SOFC systems have mainly been considered for stationary generation of electricity in combined cycles and co‐generation plants operating on natural gas or oil. New applications are opened in the area of remote power supply in residential but also automotive applications. Principles of systems considered for each application are described in the last section.
Energy storage via electrolysis/fuel cells
Authors: Divisek J. , Emonts B. 
Published: December 2010

Abstract
The application of renewable energy sources requires buffer technology between energy generation and consumption. Energy must be converted into a storable energy carrier such as hydrogen to ensure long‐term supply to the energy consumer. The components under consideration for the conversion processes and for storage are water electrolyzers, fuel cells and gas storage systems.
There are currently two competing methods in water electrolysis: alkaline and polymer membrane electrolysis. Alkaline electrolysis is an established technique operated on an industrial scale. Polymer membrane electrolysis makes use of a solid electrolyte with good conductivity for hydrogen ions and sufficient resistance to oxygen as the separator between the anode and cathode compartment. An interesting alternative from the systems engineering aspect is the bifunctional cell. Equipped with a polymer electrolyte membrane (PEM), the cell can be operated in either mode: as an electrolyzer or a fuel cell.
In fuel cells, the stored hydrogen can be directly converted into electrical energy with oxygen or atmospheric oxygen. Due to the process engineering requirements such as frequent startup and shutdown, as well as the use of hydrogen as the fuel gas, fuel cell types with low operating temperatures are especially suitable for this application, e.g., the alkaline fuel cell (AFC) and the polymer electrolyte fuel cell (PEFC).
The most economical form of gas storage is in tanks at high pressure. Suitable process components are mechanical, electrochemical and thermal compressors. The energetically most favorable process is the compression of liquid water with subsequent decomposition in a high‐pressure electrolyzer. The only hydrogen compression technique that does not need electrical energy is thermal hydrogen compression with metal hydrides.
Noramlization of porous active surfaces
Authors: Nart F. C. , Vielstich W. 
Published: December 2010

AbstractSurface area normalization of different electrocatalytic materials for fuel cell applications is of fundamental importance for the comparison of different electrode materials. In this chapter we discuss the methodology for surface area normalization using adsorbed probe molecules. Specifically the methodology using adsorption–desorption of hydrogen and carbon monoxide for normalization of active surface areas is discussed. The method entails the determination of the amount of the probe molecule adsorbed on the surface using different methods. Cyclic voltammetry can be used for both hydrogen and CO. In situ infrared spectroscopy and on line mass spectrometry can be used in addition for CO. The surface coverage of hydrogen and CO is discussed for different single crystal electrode surfaces in order to support the use of these methods.
NewCO‐tolerant catalyst concepts
Authors: Watanabe M. 
Published: December 2010

AbstractElectrocatalytic activity for H2oxidation in the presence of 100 ppm CO has been investigated on a series of binary Pt alloy electrocatalysts with nonprecious metals of various compositions, prepared easily by the sputtering method. Regardless of the composition, Pt/Fe, Pt/Ni, Pt/Co and Pt/Mo alloys have been found to exhibit excellent CO tolerance at H2oxidation similar to Pt/Ru alloy. At these CO tolerant electrodes, the equilibrium coverage of CO was suppressed to values of less than ca. 0.6. Based on X‐ray photoelectron spectroscopy, electrochemical quartz crystal microbalance and scanning tunneling microscopy data, it was found that the surfaces of all nonprecious metal alloys are composed of a thin Pt layer with an electronic structure different from that of pure Pt, indicating a modification of the electronic structure by the underlying alloys. It was found that all such CO tolerant alloys exhibit a positive chemical shift in the core‐level 4f or 4 d orbitals of Pt and vice versa. Such a modification, indicating 5 d vacancy, can be maintained until the thickness grows up to ca 2 nm, then decreases linearly with the increase of thickness and finally coincides with that of bulky Pt beyond ca. 4 nm. The lowered CO coverage, particularly of multi‐bonding, was explained as the result of a lowered 5 d‐electron donation from the Pt band to 2π orbital of CO. A weakening of bond strength between the Pt skin layer and CO was also indicated by in situ Fourier transform infrared spectroscopy, suggesting that H2oxidation sites are not blocked by CO due to its enhanced mobility. Thus, the mechanism of CO tolerance described above at the Pt skin on alloy surfaces is proposed as “detoxification mechanism”. The importance of the examination on the stability as well as the activity of the alloy combinations in the form highly‐dispersed on carbon‐black supports is pronounced from the viewpoint of the practical application to polymer electrolyte fuel cells.
Reaction mechanisms of the
O
2
reduction/evolution reaction
Authors: Gattrell M. , MacDougall B. 
Published: December 2010

Abstract
This chapter attempts to provide an overview of the understanding that has been developed on the mechanisms of reduction and evolution of oxygen. This is discussed mostly in light of oxygen reduction at platinum under close to ambient conditions, though oxygen evolution and various other electrode materials are also mentioned. A general description of this progress in understanding is provided; using results from basic electrochemical polarization and reaction order measurements, rotating ring disk electrode studies, isotopic and adsorption measurements, and insights from volcano plots. The reactions of oxygen are true electrocatalytic reactions (i.e., involving surface adsorbed intermediates) and so are sensitive to the local environment at the electrode surface reaction site. The electrode material, the crystal face, oxide species, and adsorbed electrolyte species therefore affect the reaction. Research to optimize the reaction conditions using alloys of platinum is also briefly discussed.
Oxygen reduction reaction on smooth single crystal electrodes
Authors: Ross P. N. 
Published: December 2010

Abstract

New in‐situ techniques for structure determination at the electrochemical interface have made it possible to use single crystal electrodes in kinetic studies in a definitive way. Use of techniques like surface X‐ray scattering (SXS) and/or scanning tunneling microscopy (STM) under reaction conditions assures that the single crystal surface being studied has a stable and known atomic arrangement. Specifically, this capability has made it possible to determine definitively the structure sensitivity of the oxygen reduction reaction on Pt and Au surfaces. For Pt in sulfuric and phosphoric acid electrolytes, the structure sensitivity is dominated by the inhibiting effects of anion adsorption, which is strongly structure sensitive. In nonadsorbing acids like perchlorate or triflate, the structure sensitivity is weak, probably due to the single‐site nature of the rate‐determining step, i.e., electron transfer to form adsorbed superoxide radical anion. Thus, a particle size effect is not expected for supported Pt catalyst in a PEM fuel cell cathode if the geometric change in particle shape with size is the only factor contributing, i.e., absent electronic effects like quantum confinement. For Au in alkaline electrolyte, oxygen reduction is strongly structure sensitive, with the (100) surface the only Au surface with direct 4e
−
oxidation at potentials near 0.9 V. There is no explanation available for the unique catalytic activity of Au(100) for the ORR in alkaline electrolyte. In acid electrolyte, the ORR polarization curves on Au surfaces are shifted negatively (on a RHE scale) by hundreds of mV, and the reaction becomes structure insensitive. The large effect of pH on the overpotential for ORR on Au is due to the absence of chemisorption of either O
2
or O
2
−
. The rate‐determining step on Au is inner sphere electron transfer to O
2
from O
2
−
, and this reaction step is independent of pH, i.e., the reaction occurs at a fixed potential on a SCE scale, so the overpotential (on an RHE scale) changes with pH.
Fundamental kinetics/transport processes in
MEAs
Authors: Ticianelli E. A. , Gonzalez E. R. 
Published: December 2010

Abstract
The results of fundamental and applied research on the development of dispersed catalysts, gas‐diffusion electrodes and membrane and electrode assemblies (MEAs) for polymer electrolyte fuel cells (PEFCs) are discussed. In the first part, the electrocatalysis of the oxygen reduction reaction on dispersed platinum catalysts used for the preparation of fuel cell electrodes is briefly considered. The issue is analyzed mainly in terms of the size and structure of the catalyst particles. Next, efforts on the development and single cell testing of low catalyst loading gas‐diffusion electrodes for PEFCs are reported in conjunction with the main parameters relating to the properties of the MEAs. The fuel cell polarization behavior is analyzed considering the effects of the structure and composition of the diffusion and catalytic layers of the gas‐diffusion electrode, the cell temperature and gas pressure and the thickness and the water transport through the membrane.
Methanol andCOelectrooxidation
Authors: Iwasita T. 
Published: December 2010

AbstractPresent knowledge of methanol and CO electrooxidation reactions is given in the light of electrochemical, spectroscopic and microscopic data. Strong catalytic effects on CO electrooxidation by nonmetallic adatoms (S, Se, Te) are presented and discussed. For methanol oxidation, several authors have shown, besides CO2, nonnegligible yields of formaldehyde and formic acid, depending among other factors on concentration, potential, electrode roughness and temperature. Infrared spectra assist mechanistic interpretations. Promotion of methanol oxidation by ruthenium presents a maximum effect on alloy materials at room temperature for a surface concentration of Ru between 15% and 45%.
Technical characteristics of
PEM
electrochemical capacitors
Authors: Kosek J. A. , Dweik B. M. , LaConti A. B. 
Published: December 2010

Abstract

Electrochemical capacitors, also known as supercapacitors and ultracapacitors, are capable of very high charge storage. Operating on both pseudocapacitance and double‐layer capacitance, they have demonstrated high capacitance compared to electrolytic and electrostatic capacitors. Electrochemical capacitors have been fabricated from a wide variety of materials, including precious metal oxides and transition metal nitrides as the positive and negative electrode materials, and organic, aqueous, and solid polymer electrolytes. These capacitors have been demonstrated to provide as high as 4 F cm
−2
of active electrode area. Individual cell voltages range from 1 V cell
−1
for aqueous‐based electrolytes, up to 2.5–4 V cell
−1
for organic electrolytes. This publication describes the various types of capacitors, and also compares electrochemical capacitors to batteries. Recent work in the area of electrochemical capacitors is reviewed. The fabrication and operation of all‐solid ionomer or proton‐exchange membrane electrochemical capacitor stacks is targeted for special attention. These devices have been fabricated in a wide range of sizes, ranging from 350‐cell stacks with active areas of 2 cm
2
, to 60‐cell stacks with active areas of 450 cm
2
cell
−1
. The discharge characteristics and energy storage properties of these devices are described. Specific applications of various capacitor stacks are discussed.
Hydride storage
Authors: Sandrock G. 
Published: December 2010

Abstract

The principles and application of reversible metal hydrides for H
2
storage for fuel cells are reviewed. The practical use of fuel cell waste heat is important for supplying the required heat of desorption for the hydride. A tutorial overview of hydrides is given, starting with the definitions of H capacity, thermodynamic and other important hydride properties. Using the near‐ambient‐temperature PEM fuel cell as a reference application, a review of hydrides capable of supplying H
2
at pressures of 1–10 atm (absolute) and temperatures of 0–100 °C is given. Numerous such hydriding alloys and intermetallic compounds are available, but gravimetric H‐densities are no greater than about 2 wt%, a distinct shortcoming for vehicular fuel cell applications. Although near‐ambient‐temperature hydrides have volumetric, pressure and safety advantages over advanced compressed H
2
storage, they cannot compete on weight and, probably, cost bases. The potential for hydrides with greatly improved gravimetric capacities is discussed, especially relative to nanocrystalline Mg‐alloys and alkali metal alanates.