New insight into the redox behavior of polyaniline

2011 ◽  
Vol 161 (21-22) ◽  
pp. 2510-2513 ◽  
Author(s):  
Natalia Gospodinova ◽  
Veronica Muşat ◽  
Hristo Kolev ◽  
Julia Romanova
Keyword(s):  
2020 ◽  
Vol 234 (2) ◽  
pp. 295-312 ◽  
Author(s):  
Muhammad Tariq

AbstractElectro-oxidation of Br− on platinum and gold electrode was studied in acetonitrile, methanol and mix media of acetonitrile–methanol. The mechanism of Br− oxidation in these media was investigated using CV, Semi Integration Cyclic Voltammetry, and Digital Simulation technique. Since, Br− oxidation mechanism on platinum involves the formation of Br3− as intermediate, therefore, Kstab for Br3− formation in the mixed media was estimated using digital simulation, Nelson and Iwamoto method. Redox mechanism of Br− and Br2 on gold (Au) electrode was also investigated in protic solvent such as H2O, methanol, ethanol, 1-butanol, and formic acid. It was ascertained that Br− oxidation on gold (Au) electrode in these above protic solvents involve [AuBr2]− intermediate rather than Br3−.


ACS Catalysis ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 13084-13095
Author(s):  
Patricia Rodríguez-Maciá ◽  
Nina Breuer ◽  
Serena DeBeer ◽  
James A. Birrell
Keyword(s):  

2021 ◽  
Author(s):  
Juan Manuel Arce-Ramos ◽  
Graham Rugg ◽  
Alexander Genest ◽  
Notker Rösch

Abstract With hybrid DFT calculations applied to periodic models of the bulk MoVNbTeO M1 catalyst, we examined how [TeO]2+ species in the hexagonal channels of this material stabilize nearby reduced metal centers. In particular, an S2(Mo) site, with adjacent [TeO]2+ moieties at both sides, is calculated to be reduced to Mo5+. The modeling study presented offers insight into how the redox behavior of V and Mo centers, a crucial aspect of the M1 catalyst for the selective partial oxidation of small hydrocarbons, may be fine-tuned via TeO moieties at various distances from the metal centers. Graphic Abstract TeO moieties in hexagonal channels, adjacent on either side of an S2(Mo) center, stabilize a gap state at the Mo center, facilitating its reduction to Mo5+.


1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.


1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Peter Sterling

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.


Author(s):  
J. J. Laidler ◽  
B. Mastel

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.


Author(s):  
John R. Devaney

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.


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