Controlled Periodic Illumination Enhances Hydrogen Production by over 50% on Pt/TiO2

[Image: see text] Efficient solar water photosplitting is plagued by large overpotentials of the HER and OER. Even with a noble metal catalyst, the hydrogen evolution reaction can be limited by the strong M–H bonding over some metals, such as Pt, Pd, and Rh, inhibiting hydrogen desorption. H absorption is regulated by the potential at the metal nanoparticles. Through controlled periodic illumination of a Pt/TiO(2) suspension, we hypothesized a fast variation of the photopotential that induced catalytic surface resonance on the metal, resulting in more than a 50% increase of the efficiency at frequencies higher than 80 Hz

Polyethylene glycol as shape and size controller for the hydrothermal synthesis of SrTiO3 cubes and polyhedra

Understanding the correlation between the morphological and functional properties of particulate materials is crucial across all fields of physical and natural sciences. This manuscript reports on the investigation of the effect of polyethylene glycol (PEG) employed as a capping agent in the synthesis of SrTiO3 crystals. The crucial influence of PEG on both the shape and size of the strontium titanate particles is revealed, highlighting the effect on the photocurrents measured under UV–Vis irradiation

Ascitis quilosa y síndrome de maltrato infantil

La ascitis quilosa (AQ) es una entidad rara asociada a patología del sistema linfático. El primer caso pediátrico fue reportado por Morton en 1.683 en un paciente con tuberculosis. Puede producirse por una malformación linfática congénita, una obstrucción o trauma. La etiología traumática, incluido el síndrome de maltrato infantil (SMI) representa alrededor del 20% (2). Se debe a la disrupción de los linfáticos mesentéricos con acumulación de fluído quiloso en la cavidad peritoneal. Su manejo es controvertido en razón de la experiencia limitada. En éste artículo presentamos un niño con AQ y antecedentes de maltrato que evolucionó favorablemente con soporte nutricional parenteral asociado a octreotido de somatostatina

Development of Pavement Performance Models by Combining Experimental and Field Data

The objective of this paper is to demonstrate the development of pavement performance models by combining experimental and field data. A two step approach was used. In the first step a riding quality model based on serviceability consideration is developed. The data set of the American Association of State Highways Officials (AASHO) Road Test is used to this effect. Due to the experimental nature of the AASHO Road Test data set, some of the estimated parameters of the model may be biased when the model is to be applied to predict performance in the field. In the second step, the original model parameters are reestimated by applying joint estimation allowed for with the incorporation of field data set. This data set was collected through the Minnesota Road Research Project (MnRoad). The final model is referred to as the joint model, and it can be used to predict the performance of in-service pavement sections. Joint estimation allowed for the full potential of both data sources to be exploited. First, the effect of variables not available in the first data source were identified and quantified. Further, the parameter estimates had lower variance because multiple data sources were pooled, and biases in the parameters of the experimental model were corrected. Finally, different measurements of the same property were incorporated by using a measurement error model. Thus, the methodology proposed in this paper makes optimum use of available data and yields models of improved statistical properties compared with techniques such as ordinary least squares

Effect of Performance Model Accuracy on Optimal Pavement Design

In the first part of this paper, an analysis of the data collected during the American Association of State Highway Officials (AASHO) Road Test, based on probabilistic duration modeling techniques, is presented. Duration techniques enable the stochastic nature of pavement failure time to be evaluated as well as censored data to be incorporated in the statistical estimation of the model parameters. The second part of this paper presents the use of economic optimization principles for determining the optimal design of flexible pavements. We study the effect of deterioration model accuracy on optimal design and lifecycle costs, by comparing three models. The first is a simple regression model developed by the AASHO, which forms the basis of design standards in use today. The second is a regression model that was developed with the same AASHO data set, but that includes a correction for data censoring. The third model is the probabilistic model developed in the first part of this paper. The results show that the AASHO model, when used as an input to lifecycle cost minimization, produces a pavement structural number that is lower than that produced by using the other two deterioration models. This results in shorter pavement lives and higher costs due to more frequent resurfacing. The savings in lifecycle cost accrued by using optimal structural number are shown to be quite significant, offering a sound basis for revising current design practices