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The relative contribution to electrocatalytic conversion arising from Pt-ionomer and Pt-water interfaces depends on phase segregation, porous morphology, and wetting properties of pores. A larger fraction of hydrophilic micropores will increase the contribution of Pt-water interfaces, relative to that of Pt-ionomer interfaces (Eiker-ling, 2006 Liu and Eikerling, 2008). [Pg.167]


In the context of the structural perturbations at fluid-solid interfaces, it is interesting to investigate the viscosity of thin liquid films. Eaily work on thin-film viscosity by Deijaguin and co-workers used a blow off technique to cause a liquid film to thin. This work showed elevated viscosities for some materials [98] and thin film viscosities lower than the bulk for others [99, 100]. Some controversial issues were raised particularly regarding surface roughness and contact angles in the experiments [101-103]. Entirely different types of data on clays caused Low [104] to conclude that the viscosity of interlayer water in clays is greater than that of bulk water. [Pg.246]

Only a minority of new products studied in R D enjoy commercial success, thus allocation of R D costs is another controversial issue. This... [Pg.440]

Other courts addressing this problem have refused to adopt a rule of proportional recovery. Some have asserted that such a fundamental change of a basic tort principle is more appropriately a legislative function. Others have expressed concern that the long latency period renders any reconstmction of market shares highly speculative. The Restatement notes the opposing views but takes no position on this controversial issue. [Pg.100]

Corrosion resistance The corrosion resistance of a copper deposit varies with the conditions under which it is deposited and may be influenced by co-deposited addition agents (see, for example, Raub ). Copper is, however, plated as a protective coating only in specialised applications, and the chief interest lies in its behaviour as an undercoating for nickel-chromium on steel and on zinc-base alloy. Its value for this purpose has long been a controversial issue. [Pg.520]

Research and development into polymer electrolyte battery systems continues, yet many unsolved and controversial issues, particularly relating to the inadequate understanding and control of ion dissociation and the relative mobilities of the ions, remain. Modem computational resources now allow the structures of complex systems such as polymer electrolytes to be simulated and evaluated. Computer simu-... [Pg.520]

The AX sequence (111) < (100) < (110) in Table 28 has been questioned by Valette,389,399 who proposed (110) < (100) <(111). He also suggested252 the sequence Ag < Au < Cu rather than Au < Ag < Cu. It happens that these two different pictures have been obtained using the same experimental values of E0wq. In particular, data for exactly the same electrodes of Ag are used to arrive at different conclusions. It is clear that the controversy issues from a different concept of selection of values. Trasatti410 has discussed this point at length and has proven that Valette s hydrophilicity series for Cu, Ag, and Au is based on an inadequate choice of work function values. [Pg.174]

Another, more serious controversy, issues from the data of Popov et al 382,443 a SQ c]ajrn the sequence of hydrophilicity Ag(l 11) > (100),... [Pg.175]

False negative muscle contraction tests are very rare. To date, a negative muscle contraction test rules out MH. A false negative test can be explained by the presence of two types of muscle fibers in a MH susceptible patient the response being dependent on the proportion of the two types of muscle fibers. The K-type designation is used to describe a patient who has a positive joint halothane-caffeine contracture, but a negative separate halothane or caffeine contracture. Whether K-type individuals are MH-susceptible or not is a controversial issue. [Pg.405]

Two main apoptotic pathways have been identified in mammalian cells the extrinsic pathway that is activated by the binding of ligands to cell-surface death receptors, and the intrinsic pathway that involves the mitochondrial release of cytochrome cP The activation of extrinsic and intrinsic apoptotic pathways promotes the cleavage into the active form of the pro-caspase-8 and pro-caspase-9, respectively, that mainly determine the activation of effector caspase-3. ° The intrinsic pathway is the main apoptotic pathway activated by chemotherapeutic drugs, while the cytotoxic drug-induced activation of the extrinsic pathway is a more controversial issue. ... [Pg.359]

The timing of CEA after ischemic stroke has been a controversial issue. In 1969, the Joint Study of Extracranial Arterial Occlusion reported 42% mortality after CEA in patients with neurological deficits of less than 2 weeks duration, compared with 5% mortality in patients with more than 2 weeks of symptoms. Early evidence also demonstrated an increased risk of intracerebral hemorrhage after early CEA in patients with acute stroke. This led to the conclusion that most complications occurred with early surgical intervention, and resulted in a traditional 4-6 week delay for CEA after an acute stroke. In retrospect, however, there were major problems with patient selection in these earlier reports. Many of the patients... [Pg.124]

The data presented here has provided a chronological picture of the evolution and current state of the possible positive or negative association of some methylxanthine-containing products and various types of cancer. Perhaps the best conclusion at this time is an extension to tea and other methylxanthine-containing products of the statement by Stavric" who in 1990 wrote that certain controversial issues about the effect of coffee on human health remains unresolved. Future work should focus on types and methods of preparation of teas, roasting and preparation methods for coffees, and consider the whole beverage rather than caffeine or other methylxanthine per se. Meanwhile it appears that both tea and coffee and... [Pg.342]

The conformation of nonsulfated L-idosyluronic acid residues is a controversial issue, especially on account of a possible role of the 2-O-sulfo substituent in determining the relative orientation of biologically relevant groups. However, the interproton coupling-constants observed for (nonsulfated) methyl a-D-idopyranosiduronic acid131 and dermatan sulfate350 are essentially the same as those of the sulfated L-iduronate resi-... [Pg.111]

A More Controversial Issue Is the Assertion that the Spread of Nuclear Weapons to New States Is Always Catastrophic... [Pg.129]

The most controversial issue is the number and exact stoichiometries of the iron(III)-sulfito complexes formed under different experimental conditions. Earlier, van Eldik and co-workers reported the formation of a series of [Fe(SO ) ]3-2" (n = to 3) complexes and the [Fe(S03)(0H)] complex (89,91,92). The stability constants of these species were determined by evaluating time resolved rapid-scan spectra obtained from the sub-second to several minutes time domain. The cis-trans isomerization of the complexes was also considered, under feasible circumstances. In contrast, Betterton interpreted his results assuming the formation and linkage isomerization of a single complex, [Fe(SC>3)]+ (93). In agreement with the latter results, Conklin and Hoffmann also found evidence only for the formation of a mono-complex (94). However, their results were criticized on the basis that the experiments were made in 1.0 M formic acid/formate buffer where iron(III) existed mainly as formato complex(es). Although these reactions could interfere with the formation of the sulfito complex, they were not considered in the evaluation of the results (95). Finally, van Eldik and co-workers re-examined the complex-formation reactions and presented additional data in support of... [Pg.434]

The corrections for basis set superposition errors (BSSE) with the counterpoise correction are still a controversial issue [120-122], However, some type of correction is needed for calculations on systems with weak interactions. It has been proved that only considering the BSSE meaningful results can be obtained on large systems [122], Of course, by using good quality basis sets the BSSE is less troublesome and the results obtained can be accepted, readily, as reliable. The BSSE in DFT calculations is less important than in conventional ab-initio calculations. We compute the counterpoise correction as ... [Pg.215]

Since the identification of bona-fide hydrogen bonds in solid state studies is often a controversial issue, in particular in the cases involving weak donors [10]... [Pg.9]

Interpretation of the process of fermentation by yeast was one of the most controversial issues for vitalists. Its resolution was fundamental for the future development of biochemistry. In the early nineteenth century fermentation was believed to be related to putrefaction and decay. Liebig considered it to result from the breakdown of a substance (sugar) following the admission of air to the nitrogenous components in yeast juices. After the must of grape juice had fermented, the liquid cleared and the yellow sediment, yeast, was deposited. [Pg.11]

The way in which calcium binding changes the tyrosine fluorescence of calmodulin was initially a controversial issue. In 1980, Seamon(n5) examined the binding of Ca2+ and Mg2+ by NMR and concluded that both Tyr-99 and Tyr-138 were perturbed by the first two calcium ions. Although Tyr-138 was also perturbed by the binding of the fourth calcium, both residues appeared to be associated with high-affinity domains (III and IV). [Pg.29]

Zeller S, Glaser AG, Vilhelmsson M, Rhyner C, Crameri R Immunoglobulin-E-mediated reactivity to self antigens a controversial issue. Int Arch Allergy Immunol 2007 145 87-93. [Pg.135]

As much as the nanophase segregated morphology of Nafion has been a controversial issue in the literature over several decades, the need for understanding the structure and distribution of wafer in PEMs has sfimulafed many efforfs in experimenf and theory. Major classifications of water in PEMs distinguish (1) surface and bulk wafer, (2) nonfreezable, freezable-bound, and free wafep and (3) wafer vapor or liquid water. Anofher fype of wafer offen discussed is that associated with hydrophobic regions. [Pg.369]

Hoffmann D, Hoffmann I, El-Bayoumy K (2001) The less harmful cigarette a controversial Issue. [Pg.80]


See other pages where Controversial Issues is mentioned: [Pg.37]    [Pg.1]    [Pg.33]    [Pg.221]    [Pg.376]    [Pg.227]    [Pg.160]    [Pg.208]    [Pg.46]    [Pg.42]    [Pg.331]    [Pg.92]    [Pg.419]    [Pg.189]    [Pg.19]    [Pg.315]    [Pg.206]    [Pg.43]    [Pg.326]    [Pg.221]    [Pg.361]    [Pg.10]    [Pg.13]    [Pg.125]    [Pg.249]    [Pg.128]    [Pg.128]    [Pg.75]    [Pg.419]   


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Controversial

Misapprehensions and Controversial Issues

Some Controversial Issues

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