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.     

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.     

Assessing the intangibles in water pollution control

Three methods of assessing the non‐pecuniary benefits of good quality water are suggested. One depends on calculating the implicit valuation accorded them by the existing expenditure on pollution control and from the amount of “damage” caused. A second method consists in calculating all the costs imposed on users of water before and after a control programme is put into operation. Both these methods require more information about expenditure than is at present usually available. A third proposal uses biological assessment of water quality as a representative of the other “intangibles”. Since high biological quality indicates a water suitable for any other use this could be a useful approximation. When information on expenditure is also available, it is possible to calculate a cost for achieving a given quality in a particular situation, which could be used in cost‐effectiveness comparisons of different programmes or different situations.     

Samuel Bourne of Nottingham

Abstract

Samuel Bourne was one of the great pioneers of travel photography, and the photographs which he took in India during the 1860s have become familiar to a wide audience through their inclusion in exhibitions, their use as book illustrations and also through television coverage. Although acknowledging the merit of that aspect of his work, this paper discusses the hitherto comparatively little-known role which he played in the arena of photography during the period immediately before he went to India, and also his activities in the latter part of the 19th and early 20th centuries.