Tribological properties of fluid phase phospholipid bilayers

Our recent studies showed that solid phase phospholipid bilayers play an important role in joint lubrication mechanism. We investigate the tribological properties of fluid phase bilayers depending on various experimental parameters. Bilayers containing a fluorescent lipid with a large head-group and surfaces covered with only one bilayer poorly lubricate meaning that the slip plane during shear is located in the thin aqueous layer between the bilayers. Lubrication and resistance to normal and tangential stresses are greatly improved in buffered saline solution. Bilayers prepared by vesicle fusion method improve the tribological properties of even very rough substrates by smoothing their topographical defects.     

Characterizing Bandgap Gratings in GaAs : AlAs Superlattice Structures Using Interface Phonons

Interface Raman modes were used to study quantum-well intermixing in GaAs : AlAs superlattice (SL) structures using room-temperature spatially resolved Raman spectroscopy. The intermixing was observed to degrade the interface mode intensity, which can be used as a sensitive indicator of the SL quality. This feature, along with spatially resolved photoluminescence, was used to investigate bandgap modulation in periodically intermixed bandgap gratings, fabricated using implantation induced disordering. Using interface modes instead of bulk-like modes is a promising avenue for characterizing SL structures that rely on intricate bandgap features     

Prediction of elastic and acoustic behaviors of calcarenite used for construction of historical monuments of Rabat,Morocco

Natural materials (e.g. rocks and soils) are porous media, whose microstructures present a wide diversity. They generally consist of a heterogeneous solid phase and a porous phase which may be fully or partially saturated with one or more fluids. The prediction of elastic and acoustic properties of porous materials is very important in many fields, such as physics of rocks, reservoir geophysics, civil engineering, construction field and study of the behavior of historical monuments. The aim of this work is to predict the elastic and acoustic behaviors of isotropic porous materials of a solid matrix containing dry, saturated and partially saturated spherical pores. For this, a homogenization technique based on the Mori–Tanaka model is presented to connect the elastic and acoustic properties to porosity and degree of water saturation. Non-destructive ultrasonic technique is used to determine the elastic properties from measurements of P-wave velocities. The results obtained show the influence of porosity and degree of water saturation on the effective properties. The various predictions of Mori–Tanaka model are then compared with experimental results for the elastic and acoustic properties of calcarenite.     

Effects of High Hydrostatic Pressure Processing on Hen Egg Compounds and Egg Products

High hydrostatic pressure (HHP), used alone or with other processes, is an emerging technology increasingly used in the food industry to improve microbial safety, and the functionality and bioactive properties of food products. HHP provides a way to reduce energy requirements for food processing and may contribute to improved energy efficiency in the food industry. Hen egg is used by the food industry to formulate many food products. To improve the microbiological safety of egg and egg‐derived products, HHP processing is an attractive alternative to heat‐ pasteurization and a potential technology. However, HHP treatment induces structural modifications of egg components (such as proteins) which could positively or negatively affect the physicochemical and functional properties of egg‐derived products. Improving our knowledge regarding the potential of HHP in the egg industry will add value to the final food products and increase profitability for egg producers and the food industry.     

Best practices for comparing optimization algorithms

Comparing, or benchmarking, of optimization algorithms is a complicated task that involves many subtle considerations to yield a fair and unbiased evaluation. In this paper, we systematically review the benchmarking process of optimization algorithms, and discuss the challenges of fair comparison. We provide suggestions for each step of the comparison process and highlight the pitfalls to avoid when evaluating the performance of optimization algorithms. We also discuss various methods of reporting the benchmarking results. Finally, some suggestions for future research are presented to improve the current benchmarking process.     

Effect of Cloisite® 30B on the Diffusion of Irganox 1076 in HDPE

The diffusion of a thermal stabilizer, Irganox 1076, is studied both in pure high‐density polyethylene (HDPE) and HDPE matrix filled with 1 wt% of Cloisite® 30B. The diffusion experiments are carried out by using the Roe method formed by a stack of several polymer films of 120 ± 01 μm in thickness. In this study, a simple method is used to measure the diffusion coefficient, with the aid of Fourier Transform InfraRed spectroscopy without any extraction or refining steps in the analysis. The diffusion coefficient (D_p) of both materials are obtained in the temperature range 80–100°C using the second Fick's law. By applying the Arrhenius equation to the calculated D_p coefficients, an estimation of activation energies of the diffusion process is also achieved. The results indicate that the diffusion coefficient of Irganox 1076 in HDPE has been decreased by adding 1% of Cloisite® 30B.     

The wartime kitchen: Food advice and cooking tips in Belgium during the First World War

This article addresses a special aspect of daily life in occupied Belgium during the First World War. It examines and compares the nutritional advice and the cooking tips which were given by private and public organizations, physicians, nutritional experts, and home economic teachers. Furthermore, the article compares these recommendations with actual practices, through the personal testimonies of diaries and wartime memories. This analysis results in three main conclusions. Firstly, it is clear that during the war, the diet (and the advice given on food) had to be adjusted on a regular basis, depending on the availability of foodstuffs. As the war progressed, fewer animal products were consumed; more expensive calories were gradually substituted by cheaper ones. The import of American foodstuffs and the search for ersatz products became increasingly important, especially during the “hunger winter” of 1916–1917. Secondly, this article underlines the influential role of experts in promoting the latest nutritional science (such as the concept of calories) in light of the war situation. It demonstrates that at the beginning of the war, experts such as agronomists and physicians published relatively technical brochures, written in a language that was very far removed from the general population. From 1916 onwards, female authors especially published cookery booklets in an easily understandable language in which they presented recipes and menus that were nutritious, cheap, and easy to prepare. Thirdly, it emphasizes the importance of women in shaping and defining the eating experience during the war. Housewives were most especially faced with the daily price increases and with the limited supply of both familiar and unfamiliar foodstuffs; hence it was they to whom the food recommendations within these wartime cookery booklets were primarily aimed.     

Model-based approaches for interoperability of next generation enterprise information systems: state of the art and future challenges

Enterprise businesses are more than ever challenged by competitors that frequently refine and tailor their offers to clients. In this context, enterprise information systems (EIS) are especially important because: (1) they remain one of the last levers to increase the performance and competitiveness of the enterprise, (2) we operate in a business world where the product itself has reached a limit of performance and quality due to uniform capacity of industrial tools in a globalized economy and (3) the EIS can increase the product value thanks to additional digital services (built on data associated to the product) in order to meet and fit better client’s needs. However, the use of EISs reaches a limit in collaborative environments because enterprises management methods diverge and EISs are mainly inflexible resource packages that are not built with an interoperability objective. Consequently, we need to make EISs interoperable in order to achieve the needed gains competitiveness and performance. This paper contribution can be summarized as follows: (1) it relates existing work and it examines barriers that, at the moment, are preventing further improvements due to current methodological and technological limits, and (2) it proposes a conceptual framework and five challenges that model based approaches must overcome to achieve interoperability between EIS in the near and long term.