Cobalt and chromium exposure affects osteoblast function and impairs the mineralization of prosthesis surfaces in vitro.

Cobalt (Co) and chromium (Cr) ions and nanoparticles equivalent to those released through tribo-corrosion of prosthetic metal-on-metal (MOM) bearings and taper junctions are detrimental to osteoblast activity and function in-vitro when examined as individual species. Here we examined the effects of Co(2+) :Cr(3+) and Co(2+) :Cr(6+) combinations on osteoblast-like SaOS-2 cellular activity, alkaline phosphatase (ALP) activity and mineralization to better reflect clinical exposure conditions in vivo. We also assessed the effect of Co(2+) :Cr(3+) combinations and Co:Cr nanoparticles on SaOS-2 cell osteogenic responses on grit-blasted, plasma-sprayed titanium-coated and hydroxyapatite-coated prosthesis surfaces. Cellular activity and ALP activity were reduced to a greater extent with combination treatments compared to individual ions. Co(2+) and Cr(3+) interacted additively and synergistically to reduce cellular activity and ALP activity respectively, whilst the Co(2+) with Cr(6+) combination was dominated by the effect of Cr(6+) alone. Mineralization by osteoblasts was greater on hydroxyapatite-coated surfaces compared to grit-blasted and plasma-sprayed titanium-coated surfaces. Treatments with Co(2+) :Cr(3+) ions and Co:Cr nanoparticles reduced the percentage mineralization on all surfaces, with hydroxyapatite-coated surfaces having the least reduction. In conclusion, our data suggests that previous studies investigating individual metal ions underestimate their potential clinical effects on osteoblast activity. Furthermore, the data suggests that hydroxyapatite-coated surfaces may modulate osteoblast responses to metal debris. This article is protected by copyright. All rights reserved

Thermoelectric properties of Al-doped mesoporous ZnO thin films

Al-doped mesoporous ZnO thin films were synthesized by a sol-gel process and an evaporation-induced self-assembly process. In this work, the effects of Al doping concentration on the electrical conductivity and characterization of mesoporous ZnO thin films were investigated. By changing the Al doping concentration, ZnO grain growth is inhibited, and the mesoporous structure of ZnO is maintained during a relatively high temperature annealing process. The porosity of Al-doped mesoporous ZnO thin films increased slightly with increasing Al doping concentration. Finally, as electrical conductivity was increased as electrons were freed and pore structure was maintained by inhibiting grain growth, the thermoelectric property was enhanced with increasing Al concentration. © 2013 Min-Hee Hong et al

Design and Fabrication of Electrolyte-Supported Tubular SOFC Combined with Supercritical Water Oxidation on Biomass Gas

Solid oxide fuel cells (SOFCs) are relatively simple and environmental friendly devices for the production of electricity from hydrocarbons. The use of a high pressure supercritical water (SCW) reactor containing a SOFC has the potential for using a multitude of logistical liquid fuels that would otherwise not be possible in a regular SOFC system. A SOFC-SCW system was designed to allow the anode to be exposed to the pressure and chemical milieu of the supercritical water oxidation reactor. The effects of the amount of water/fuel and oxygen fed into the reactor under SCW conditions at 400 degrees C were studied. The effects on electrochemical performance as well as preliminary results on a number of feed stocks, for example pectin, are also described.open1111Nsciescopu

Effect of surfactant concentration variation on the thermoelectric properties of mesoporous ZnO

The electrical and thermal conductivities and the Seebeck coefficient of mesoporous ZnO thin films were investigated to determine the change of their thermoelectric properties by controlling surfactant concentration in the mesoporous ZnO films, because the thermoelectric properties of mesoporous ZnO films can be influenced by the porosity of the mesoporous structures, which is primarily determined by surfactant concentration in the films. Mesoporous ZnO thin films were successfully synthesized by using sol-gel and evaporation-induced self-assembly processes. Zinc acetate dihydrate and Brij-76 were used as the starting material and pore structure-forming template, respectively. The porosity of mesoporous ZnO thin films increased from 29% to 40% with increasing surfactant molar ratio. Porosity can be easily altered by controlling the molar ratio of surfactant/precursor. The electrical and thermal conductivity and Seebeck coefficients showed a close correlation with the porosity of the films, indicating that the thermoelectric properties of thin films can be changed by altering their porosity. Mesoporous ZnO thin films with the highest porosity had the best thermoelectric properties (the lowest thermal conductivity and the highest Seebeck coefficient) of the films examined. © 2013 Min-Hee Hong et al

Staged and non-staged anaerobic filters : microbial activity segregation, hydrodynamic behaviour and performance

This work describes a comparative study of staged and non-staged anaerobic flters for treating a synthetic dairy waste under similar operating conditions. The effect of increasing the substrate concentration from 3 to 12 g COD dmˉ³ at a constant hydraulic residence time (HRT) of 2 days was evaluated with respect to overall reactor performance, biogas production, volatile fatty acids profiles along the height, methanogenic and acidogenic activity distribution, and hydrodynamic behaviour. The potential maximum specific methanogenic activity against acetate, hydrogen, propionate and butyrate and the lactose specific activity were determined for sludge sampled from three different points in each reactor, under two operating conditions (influent COD of 3 and 9 g COD dmˉ³). Although all trophic groups involved in the anaerobic process were found throughout the reactors, it was possible to identify different specific sludges at different heights in both reactors. Performances of the two configurations were very similar under the operating conditions tested and the plug flow behaviour of the staged reactor was clearly reduced when the influent concentration increased from 3 to 9 g COD dmˉ³.EU Human Capital and Mobility network Improved Application of Anaerobic Digestion Technology - EXBCHRXCT 930262.Fundação para a Ciência e a Tecnologia – PEAM/SEL/517/95

An Automated WSDL Generation and Enhanced SOAP Message Processing System for Mobile Web Services

Web services are key applications in business-to-business, business-to-customer, and enterprise applications integration solutions. As the mobile Internet becomes one of the main methods for information delivery, mobile Web Services are regarded as a critical aspect of e-business architecture. In this paper, we proposed a mobile Web Services middleware that converts conventional Internet services into mobile Web services. We implemented a WSDL (Web Service Description Language) builder that converts HTML/XML into WSDL and a SAOP (Simple Object Access Protocol) message processor. The former minimizes the overhead cost of rebuilding mobile Web Services and enables seamless services between wired and wireless Internet services. The latter enhances SOAP processing performance by eliminating the Servlet container (Tomcat), a required component of typical Web services implementation. Our system can completely support standard Web Services protocol, minimizing communication overhead, message processing time, and server overload. Finally we compare our empirical results with those of typical Web Service