Reactions of ethanol over CeO2 and Ru/CeO2 catalysts

The reaction of ethanol has been investigated on Ru/CeO2 in steady state conditions as well as with temperature programmed desorption (TPD). High resolution transmission electron microscopy (HRTEM) images indicated that the used catalyst contained Ru particles with a mean size of ca. 1.5 nm well dispersed on CeO2 (of about 12–15 nm in size). Surface uptake of ethanol was measured by changing exposure to ethanol followed by TPD. Saturation coverage is found to be between 0.25 and 0.33 of a monolayer for CeO2 that has been prior heated with O2 at 773 K. The main reactions of ethanol on CeO2 during TPD are: re-combinative desorption of ethanol; dehydrogenation to acetaldehyde; and dehydration to ethylene. The dehydration to ethylene occurs mainly in a small temperature window at about 700 K and it is attributed to ethoxides adsorbed on surface-oxygen defects. The presence of Ru considerably modified the reaction of ceria towards ethanol. It has switched the desorption products to CO, CO2, CH4 and H2. These latter products are typical reforming products. Ethanol steam reforming (ESR) conducted on Ru/CeO2 indicated that optimal reaction activity is at about 673 K above which CO2 production declines (together with that of H2) due to reverse water gas shift. This trend was well captured during ethanol TPD where CO2 desorbed about 50 K below than CO on both oxidized and reduced Ru/CeO2 catalysts.Peer ReviewedPostprint (author's final draft

Oxidation of Low Valent Sulphur Compounds with Lead Tetraacetate: Part II- Potentiometric Determination of Pb(IV) Acetate by Reduction with Thiosulphate or Metabisulphite

195-19

Oxidation of Low Valent Sulphur Compounds with Lead Tetraacetate: Part III- Determination of Tri- & Tetrathionates & the Redox Potential of Sulphate- Trithionate System

812-81

Mixed-Ligand Complexes of Fe(II) & Cu(II) with Alizarin Maroon as a Primary Ligand & 5-Sulphosalicylic Acid as a Secondary Ligand

231-23

Highly acid-durable carbon coated Co3O4 nanoarrays as efficient oxygen evolution electrocatalysts

Most oxygen evolution reaction (OER) electrocatalysts are not stable in corrosive acids. Even the expensive RuO2 or IrO2, the most acid-resistant oxides, can be dissolved at an oxidative potential. Herein, we realize that the failures of OER catalysts are mostly caused by the weak interface between catalysts and the substrates. Hence, the study of the interface structure between catalysts and substrates is critical. In this work, we observe that the cheap OER catalysts Co3O4 can be more durable than the state-of-the-art RuO2 if the interface quality is good enough. The Co3O4 nanosheets deposited on carbon paper (Co3O4/CP) is prepared by electroplating of Co-species and followed by a two-step calcination process. The 1st step occurs in vacuum in order to maintain the surface integrity of the carbon paper and converts Co-species to Co(II)O. The 2nd step is a calcination in ambient conditions which enables the complete transformation of Co(II)O to Co3O4 without degrading the mechanical strength of the Co3O4-CP interface. Equally important, an in situ formation of a layer of amorphous carbon on top of Co3O4 further enhances the OER catalyst stability. Therefore, these key advances make the Co3O4 catalyst highly active toward the OER in 0.5 M H2SO4 with a small overpotential (370 mV), to reach 10 mA/cm2. The observed long lifetime for 86.8 h at a constant current density of 100 mA/cm2, is among the best of the reported in literature so far, even longer than the state-of-art RuO2 on CP. Overall, our study provides a new insight and methodology for the construction of a high-performance and high stability OER electrocatalysts in corrosive acidic environments

Le mélanome primitif de la muqueuse génitale féminine: à propos de trois observations et revue de littérature

Le mélanome malin primitif de l'appareil génital féminin est une tumeur extrêmement rare. Il est fréquemment observé au niveau de la vulve mais il est rare au niveau du col utérin et du vagin. Il est le plus souvent   diagnostiqué à un stade tardif à l'occasion de métrorragies ou de massetumorale. Son histogénèse a été longtemps débattue. Le diagnostic est anatomo-pathologique avec recours nécessaire à l'étude   immunohistochimique. Sa prise en charge n'est pas codifiée avec plusieurs thérapeutiques proposées notamment dans le mélanome métastatique.Son pronostic est désastreux, associé à un taux élevé de récidives et à une courte survie. Les auteurs présentent trois observations, de  mélanomes primitifs vaginal, vulvaire et cervical, chez trois patientes âgées  respectivement de 70, 65 et 40 ans. Et à travers ces observations, ils mettent en relief les principaux aspects cliniques, histologiques, thérapeutiques de cette entité avec une revue de la littérature

Non-CA resists for 193nm immersions lithography: Effects of chemical structure on sensitivity

Initial studies are presented on the use of polysulfones as non-chemically amplified resists (non-CARs) for 193 nm immersion lithography. Polynorbornene sulfone films on silicon wafers have been irradiated with 193 nm photons in the absence of a photo-acid generator. Chemical contrast curves and contrast curves were obtained via spectroscopic ellipsometry and grazing angle - attenuated total reflectance FTIR spectroscopy. Results were consistent with previously reported mechanisms for the degradation of aliphatic polysulfones with ionizing radiation. It was shown that E0 values could be reduced significantly by using a post exposure bake step, which propagated depolymerization of the polymer. Initial patterning results down to 50 nm half pitch were demonstrated with EUV photons

Development of an operational high refractive index resist for 193nm immersion lithography

Generation-three (Gen-3) immersion lithography offers the promise of enabling the 32nm half-pitch node. For Gen-3 lithography to be successful, however, there must be major breakthroughs in materials development: The hope of obtaining numerical aperture imaging 1.70 is dependent on a high index lens, fluid, and resist. Assuming that a fluid and a lens will be identified, this paper focuses on a possible path to a high index resist. Simulations have shown that the index of the resist should be 1.9 with any index higher than 1.9 leading to an increased process latitude. Creation of a high index resist from conventional chemistry has been shown to be unrealistic. The answer may be to introduce a high index, polarizable material into a resist that is inert relative to the polymer behavior, but will this too degrade the performance of the overall system? The specific approach is to add very high index (~2.9) nanoparticles to an existing resist system. These nanoparticles have a low absorbance; consequently the imaging of conventional 193nm resists does not degrade. Further, the nanoparticles are on the order of 3nm in diameter, thus minimizing any impact on line edge roughness (LER)