Enhancement of the advanced Fenton process (Fe0/H2O2) by ultrasound for the mineralization of phenol

In this study, a successful mineralization of phenol was achieved by means of coupling zero-valent iron (ZVI) particles, hydrogen peroxide and a short input of ultrasonic irradiation. This short sono-advanced Fenton process (AFP) provided a better performance of ZVI in a subsequent silent degradation stage, which involves neither extra cost of energy nor additional oxidant. The short input of ultrasound (US) irradiation enhanced the activity of the Fe0/H2O2 system in terms of the total organic carbon (TOC) removal. Then, the TOC mineralization continued during the silent stage, even after the total consumption of hydrogen peroxide, reaching values of ca. 90% TOC conversions over 24 h. This remarkable activity is attributed to the capacity of the ZVI/iron oxide composite formed during the degradation for the generation of oxidizing radical species and to the formation of another reactive oxidant species, such as the ferryl ion. The modification of the initial conditions of the sono-AFP system such as the ultrasonic irradiation time and the hydrogen peroxide dosage, showed significant variations in terms of TOC mineralization for the ongoing silent degradation stage. An appropriate selection of operation conditions will lead to an economical and highly efficient technology with eventual large-scale commercial applications for the degradation organic pollutants in aqueous effluents

Recubrimientos bioactivos: Hidroxiapatita y titania

Peer Reviewe

On the effects of environmental conditions on wind turbine performance: an offshore case study

Monitoring wind turbine (WT) performance offers a means of identifying abnormal operation, but only if natural disturbances of the operating regime change can be excluded. WT performance monitoring usually relies on the analysis of operational power curves, generally based on data from the supervision control and data acquisition system. However, these curves do not reflect the source of variability, negatively affecting the capabilities for detecting WT abnormal performance. This work aims at understanding and quantifying changes in WT performance variability due to different environmental conditions during normal and wake-free operating conditions, based on an offshore case study. The magnitude of performance fluctuations is highly influenced by environmental conditions, being higher during high turbulence intensity and low wind shear conditions. The Taylor law, with small time windows, is suitable to describe them for low-mid winds in the absence of dedicated wind measurements, often not permanently available offshore, and could potentially result in more effective performance monitoring solutions. Nevertheless, the heteroskedastic nature of the power deviations negatively affects fitting possibilities. The results support the importance of using low data aggregation periods to understand the dynamics of WT performance

Comparing two antibacterial treatments for bioceramic coatings at short culture times

Plasma-sprayed hydroxyapatite coatings were employed industrially for decades to improve osteointegration of articular implants, but many studies have warned about the problems inherent to this procedure (mechanical properties, harmful phases). Consequently, a combination of hydroxyapatite with TiO2 sprayed by high velocity oxy-fuel spray was considered in this study. As infection after joint replacement surgery is one of the most critical concerns when considering implant performance, it is necessary to study possible ways to reduce or eliminate it. Two coating treatments were chosen for this study: addition of a percentage of ZnO and immersion in gentamicin for 24 h. Furthermore, three bacteria were considered: Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The evolution of bacteria viability in solution was measured at 0, 2, and 4 h; and plate assays were performed to study antibacterial effects by diffusion. The results show an important antibacterial effect of the as-sprayed coating, attributed to the presence of -OH radicals on the surface. The presence of ZnO did not have any additional influence on bacteria viability, but gentamicin-treated samples showed an improvement in antibacterial behavior for Gram-negative bacteria in solution, as well as a bactericidal effect in diffusion conditions

The effect of beta-tricalcium phosphate on mechanical and thermal performances of poly(lactic acid)

Orthophosphates are bioactive crystals with similar structure, in terms of elemental composition and crystal nature, to human bone. In this work, biocomposite materials were prepared with poly(lactic acid) (PLA) as matrix, and betatricalcium phosphate (b-TCP) as osteoconductive filler by extrusion-compounding followed by conventional injection molding. The b-TCP load content was varied in the 10 40 wt% range and the influence of the b-TCP load on mechanical performance of PLA/b-TCP composites was evaluated. Mechanical properties of composites were obtained by standardized tensile, flexural, impact, and hardness tests. Thermal analysis of composites was carried out by means of differential scanning calorimetry; degradation at high temperatures was studied by thermogravimetric analysis; and the effect of the b-TCP load on dynamical response of composites was studied by mechanical thermal analysis in torsion mode. The bestbalanced properties were obtained for PLA composites containing 30 wt% b-TCP with a remarkable increase in the Young s modulus. These materials offer interesting properties to be used as base materials for medical applications such as interference screws due to high stiffness and mechanical resistance.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by "Conselleria d'Educacio, Cultura i Esport" - Generalitat Valenciana ref: GV/2014/008.Ferri Azor, JM.; Gisbert, I.; García Sanoguera, D.; Reig Pérez, MJ.; Balart Gimeno, RA. (2016). The effect of beta-tricalcium phosphate on mechanical and thermal performances of poly(lactic acid). Journal of Composite Materials. 50(30):4189-4198. https://doi.org/10.1177/0021998316636205S41894198503

The incidence of breast cancer in the General Practice Research Database compared with national cancer registration data

Breast cancer incidence rates in the UK from 1990 to 1996 among women aged 35–69 estimated from the General Practice Research Database (GPRD) were closely similar to those reported by the Office for National Statistics from cancer registration data (ONS). The GPRD is a valuable and up-to-date resource for further study of the incidence of breast cancer in the UK as well as changes in cancer treatment and their relation to survival trends. © 2000 Cancer Research Campaign http://www.bjcancer.co

Biodiesel production from used cooking oil using a novel surface functionalised TiO2 nano-catalyst

A novel, efficient and recyclable mesoporous TiO2/PrSO3H solid acid nano-catalyst was synthesised by the post-synthetic grafting of propyl sulfonic acid groups onto a mixed phase of a TiO2 support. The synthesised nano-catalyst was characterised using FTIR, SEM, TEM, XPS, N2 adsorption–desorption isotherms, XRD, DSC, TGA, and CHNS analysis. The percentage of loading for propyl sulfonic acid on the TiO2 support was calculated using CHNS analysis and TGA. The catalytic performance of TiO2/PrSO3H on the production of the fatty acid methyl esters (FAME) via simultaneous esterification and transesterification reactions from used cooking oil (UCO) has been studied. The effects of different process parameters showed that 98.3% of FAME can be obtained after 9 hrs of reaction time with 1:15 molar ratio of oil to methanol, 60 °C reaction temperature and 4.5 wt% catalyst loading. It was also found that the one-pot post-surface functionalisation strategy with hydrophilic functional groups (-SO3H) enhanced the acid strengths of the nano-catalyst providing more acid sites for the reactants, and improving the accessibility of methanol to the triglycerides (TG)/free fatty acids (FFAs) by increasing the pore volumes/sizes of the nano-catalyst. The solid acid nano-catalyst was re-used in four consecutive runs without significant loss of catalytic efficiency. Finally, the synthesised biodiesel fuel satisfied ASTM and EN standards

Enhancing the bioactivity of polymeric implants by means of cold gas spray coatings

Nanostructured anatase coatings were built-up on biocompatible polyetheretherketone (PEEK) by means of cold gas spray (CGS). Titanium layer was previously desposited, which acted as bond coat between PEEK and metal oxide. Semicrystalline polymer was not degraded during the spraying process and starting composition of titanium dioxide was not affected. TiO2 was homogeneously obtained onto CGS Ti layer and completely covered the piece. Primary human osteoblasts were seeded onto biomaterials and in vitro cell experiments provided evidence to confirm that nanostructured anatase coatings deposited by cold gas spray improve the performance of PEEK implants