200 research outputs found
The effect of Pt surface orientation on the oscillatory electro-oxidation of glycerol
In the present paper, we have studied the influence of (bi)sulfate anion (0.1 and 0.5 M) on the electro-oxidation of glycerol on basal Pt(hkl) and stepped surfaces belonging to the series of Pt(S)[n(1 1 1) × (1 1 1)]. Cyclic voltammograms and derivative voltammetry pointed out that the catalytic activity decreases for Pt(1 1 1) and Pt(1 1 0) and, to a minor extent, for stepped surfaces in 0.5 mol/L H2SO4. Chronoamperometric curves demonstrated that above 0.60 V (vs RHE), for both concentrations (0.1 and 0.5 mol/L H2SO4), stepped surfaces and Pt(1 1 0) showed greater ability to catalyze the glycerol electro-oxidation in comparison with Pt(1 1 1). Potential oscillations were mapped along with slow galvanodynamic sweeps and studied at constant current. For Pt(1 1 1), no oscillations were found in the galvanodynamic regime, however, under the galvanostatic regime, period 1 oscillations were observed after a long induction period. The oscillations showed a very similar profile for stepped surfaces, even for the Pt(3 3 2) surface, which has a high density of (1 1 0) steps. Pattern changes were observed only for Pt(1 1 0) compared to other surfaces. Therefore, we conclude that (1 1 0) step sites influence the oscillatory behavior, thus the insertion of the steps favors the path of formation of inactive species, which compete for the same catalytic sites in a given potential region. The extinction of the mechanism oscillatory occurs differently due to the intrinsic characteristics of each surface electrode for the formation of (hydro)oxides.The authors acknowledge FAPESP (Grants No. 2013/16930-7 and 2019/22183-6), FAPEAL (process 60030-001076/2016), CAPES - Brasil (CAPES, Grant No. 0001, and for the scholarship, GBM, 88887.341974/2019-00). HV (Grant No. 306060/2017-5) and GTF (Grant No. 313455/2021-0) acknowledge CNPq for financial support. We gratefully acknowledge the support of the RCGI – Research Centre for Gas Innovation, hosted by the University of São Paulo (USP) and sponsored by FAPESP (2014/50279-4 and 2020/15230-5) and Shell Brazil, and the strategic importance of the support given by ANP (Brazil’s National Oil, Natural Gas, and Biofuels Agency) through the R&D levy regulation
PI3K/AKT/mTOR pathway activation in actinic cheilitis and lip squamous cell carcinomas
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156448/2/jdv16420_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156448/1/jdv16420.pd
Influencia del uso de las tecnologías de internet en el capital estructural
[ESP] Desde la irrupción de Internet, las empresas han emprendido una carrera para posicionarse en el
negocio electrónico. Sin embargo, esta inversión se está realizando sin tener una realimentación clara
de la rentabilidad que el uso de estas tecnologías les reporta. Este trabajo analiza en que medida el
comportamiento de la empresa en Internet se asocia al capital estructural. Para ello, han sido
aplicadas técnicas de regresión jerárquica sobre una muestra de 164 empresas del sector de las
Telecomunicaciones. Los resultados muestran que la mera presencia en Internet no aporta
necesariamente un valor a la empresa, en contraposición a empresas que realmente hacen
transacciones en Internet, además se observa que el tamaño se asocia positivamente al capital
estructural. [ENG]From the irruption of Internet, companies have undertaken a career for obtaining a position in the
electronic business. However, this investment is being accomplishing without having a clear
feedback of the profitability that the use of these technologies reports. This work analyzes in which
measured the behavior of the company in Internet is associated to the structural capital. In doing so,
we have applied hierarchic regression on a sample of 164 companies of the Telecommunications
industry. Our results show that the mere presence in Internet does not provide necessarily a value to
the company, in contraposition to companies that actually make transactions in Internet, furthermore,
it is observed that the size is associated positively to the structural capital
Digital play and the actualisation of the consumer imagination
In this article, the authors consider emerging consumer practices in digital virtual spaces. Building on constructions of consumer behavior as both a sense-making activity and a resource for the construction of daydreams, as well as anthropological readings of performance, the authors speculate that many performances during digital play are products of consumer fantasy. The authors develop an interpretation of the relationship between the real and the virtual that is better equipped to understand the movement between consumer daydreams and those practices actualized in the material and now also in digital virtual reality. The authors argue that digital virtual performances present opportunities for liminoid transformations through inversions, speculations, and playfulness acted out in aesthetic dramas. To illustrate, the authors consider specific examples of the theatrical productions available to consumers in digital spaces, highlighting the consumer imagination that feeds them, the performances they produce, and the potential for transformation in consumer-players
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