Oxidation resistance of β-Sialon/TiN composites: an ion beam analysis (IBA) study

The oxidation resistance of β-Sialon processed with Y₂O₃ sintering additive and β-Sialon/TiN composites containing 1–10 wt% TiN was studied using ion beam analysis (IBA) techniques, augmented by XRD and SEM measurements. Rutherford backscattering spectrometry was used to monitor the diffusion of Y and Ti in the oxidised samples, and the diffusion of oxygen and nitrogen was observed by particle-induced gamma emission and nuclear reaction analysis. These techniques showed that in the Sialon control sample without TiN, oxygen was the first element to migrate at 1000 °C, followed by Y and N at 1100 °C. At 1200 °C, a N-poor, Y- and O-rich oxidised layer was formed, containing crystalline Y₂Si₂O₇. In the TiN-containing samples, Si, Al, Y and Ti were very mobile even at 1000 °C and the surface nitrogen was depleted by 1250 °C. The combined presence of yttrium aluminium garnet (YAG) and TiN protects the β-Sialon phase by forming an oxygen-rich crystalline barrier layer. The oxidation products of TiN in these composites are TiO₂ and Y₂Ti₂O_7. The details of the oxidation mechanism of the β-Sialon/TiN composites provided by these IBA studies (movement of yttrium and titanium, replacement of nitrogen by oxygen in the glassy yttrium phase and major crystalline and chemical changes in an outer oxidised layer) could not readily have been obtained by any other techniques, and illustrate the value of IBA for oxidation studies of non-oxide ceramics.     

The Role of Housing Stock Transfer Organisations in Neighbourhood Regeneration: Exploring the Relationship between Regeneration, ‘New Localism’ and Social Networks

This paper defines stock transfer organisations and argues that they have a pivotal role in accessing funding for the social and economic regeneration of their communities. It places housing and regeneration policy within the changing policy context of ‘new localism’, which, at least rhetorically, emphasises improvement in public services, multi-level governance structures and devolution of decision making. For stock transfer housing organisations this means an increasing need to engage in a wide range of partnerships and policy forums. Bourdieu's notion of habitus, i.e. social, economic and cultural capital, is used to explore the possible reasons for the differential approach of stock transfer organisations to regeneration and the variable success at engaging in a wide range of regeneration activity and attracting additional resources.     

The design and production of Ti-6Al-4V ELI customized dental implants

This paper addresses the production of customized Ti-6Al-4V ELI dental implants via electron beam melting (EBM). The melting of Ti-6Al-4V ELI powder produces implants with great biocompatibility, fi ne mechanical performance, and a high bone ingrowth potential. The EBM technology is used to produce one-component dental implants that mimic the exact shape of the patient’s tooth, replacing the traditional, three-component, “screw-like” standardized dental implants currently used. The new generation of implants provides the possibility of simplifying pre-insertion procedures leading to faster healing time, and the potential of better and stronger osseointegration, specifi cally through incorporating lattice structure design.     

Design,implementation and evaluation of a virtual storage system

Large organizations always have a strong demand for storage from data‐intensive applications and instruments. In this paper, we present the design, implementation, and evaluation of a new virtual storage system, Storage@desk, which can aggregate a large number of distributed machines within an organization to provide storage services with quality of service guarantees. Because storage virtualization is the prominent goal, Storage@desk provides clients with the abstraction of a hard drive by utilizing the Internet SCSI protocol. As such, data access to new storage services is transparent so that clients do not need to modify any existing applications nor change their current practices. Storage@desk replicates data and employs version‐based journaling for high availability. It utilizes a market‐based model for resource management and a feedback controller for automated performance control. We have developed a prototype of Storage@desk that implements the core components. Copyright © 2010 John Wiley & Sons, Ltd.     

Association of indigo with zeolites for improved color stabilization

The durability of an organic color and its resistance against external chemical agents and exposure to light can be significantly enhanced by hybridizing the natural dye with a mineral. In search for stable natural pigments, the present work focuses on the association of indigo blue with several zeolitic matrices (LTA zeolite, mordenite, MFI zeolite). The manufacturing of the hybrid pigment is tested under varying oxidizing conditions, using Raman and ultraviolet-visible (UV-Vis) spectrometric techniques. Blending indigo with MFI is shown to yield the most stable composite in all of our artificial indigo pigments. In the absence of defects and substituted cations such as aluminum in the framework of the MFI zeolite matrix, we show that matching the pore size with the dimensions of the guest indigo molecule is the key factor. The evidence for the high color stability of indigo@MFI opens a new path for modeling the stability of indigo in various alumino-silicate substrates such as in the historical Maya Blue pigment.     

Phenolic compounds and plant extracts as potential natural anti-obesity substances

One strategy to prevent obesity could consist in the inhibition of the pancreatic lipase (PL). In an attempt to find natural antiobesity agents, phenolic compounds (PCs) and plant extracts were investigated on PL activity. Epigallocatechin-3-gallate > kaempferol and quercetin were detected as potent PL inhibitors, with ICs₅₀ of 0.8, 13.4 and 21.5 μM, respectively. Plant extracts from green tea and grape seed also shown potent inhibitory effect. Selected PCs were then assayed in an in vitro model of simulated intestinal fat digestion, based on the lipolysis of triolein. In such conditions closer to physiological reality, resveratrol, but also epigallocatechin-3-gallate and quercetin reduced the triolein digestion to ±50%. This could delay or decrease in vivo fatty acid absorption by enterocytes. This work therefore suggests that some PCs, at concentrations easily reached in the intestine following ingestion of tea beverages, fruits or vegetables, but also flavonoid-enriched supplements or functional food, are potential candidates for obesity prevention.     

Torque minimisation of the 2-DOF serial manipulators based on minimum energy consideration and optimum mass redistribution

This paper deals with the analytically tractable solution for input torques minimisation of two degrees of freedom serial manipulators based on minimum energy control and optimal redistribution of movable masses. The minimisation problem is carried out in two steps: at first, the optimal trajectory of the manipulator is defined as a function, which leads to the minimisation of energy consumption. Then, by introducing the obtained trajectory into dynamic equations, the torques are reduced by using the optimal redistribution of movable masses, which is carried out via an adaptive counterweight system. For this purpose, the torques due to the dynamic loads of the counterweights are presented as a function of the counterweight positions. The conditions for optimal dynamic balancing are formulated by minimisation of the root-mean-square value of the input torque including the dynamic loads of the unbalanced manipulator and counterweights. The suggested approach is illustrated by numerical simulations carried out using ADAMS software.