Sandwich Panels with a Core Segmented into Topologically Interlocked Elements

We present a novel approach for designing lightweight sandwich structures by using an assembly of topologically interlocked building blocks as a core of the sandwich. The results of a study in three point bending tests demonstrate a significant increase in maximum deflection before failure and absorbed energy over that of a sandwich with a monolithic core.     

Characterisation and phenolic profiles of two rare olive oils from southern Tunisia: Dhokar and Gemri‐Dhokar cultivars

BACKGROUND: The aim of this work was to study the chemical characteristics of two Tunisian cultivars, namely Dhokar and Gemri‐Dhokar, to analyse the fatty acids, sterols, triacylglycerols, triterpenic alcohols, and to determine the phenolic composition and oxidative stability. RESULTS: Among the rare varieties, Gemri‐Dhokar olive oil had the highest value of oleic acid (69.39%) whereas Dhokar oil was noteworthy for its lower content of phenolic compounds (94.56 mg kg^?1 gallic acid equivalents of oil) and presented the highest level of palmitic acid (19.37%). The main sterols found in all olive oil samples were β‐sitosterol and Δ5‐avenasterol, whereas cholesterol and 24‐methylenecholesterol were also found in all samples but in lower amounts. Two triterpenic dialcohols (erythrodiol and uvaol) were also detected and their content ranged from 1.45 to 2.30%, in Gemri‐Dhokar and Dhokar olive oil, respectively. Ten phenolic compounds were identified. In all samples, the main phenols found were oleuropein aglycon and pinoresinol. These phenolic compounds showed significant correlations with oxidative stability. CONCLUSION: The analytical parameters of two oils that were determined in this study were greatly influenced by genetic factors (cultivar). © 2012 Society of Chemical Industry     

Influence of Oven-Drying Temperature on Physicochemical and Functional Properties of Date Fibre Concentrates

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence of oven-drying temperatures of date fibre concentrates (DFC) on their physicochemical and functional properties for possible use as a potential fibre source in the enrichment of food. DFC from 11 Tunisian date cultivars were dried at different temperatures (40, 50 and 60 °C) and analysed regarding proximate composition (moisture, ash, protein and lipids), physicochemical (water activity (a _w), pH) and functional properties (water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and emulsifying capacity (EC)). DFC dried at different temperatures showed interesting functional characteristics such as hydration properties, high OHC (2.73–4.60 g oil/g dry fibre) and EC (5.93–12.87%) values. Although drying temperatures promoted little modifications affecting the physicochemical properties of DFC, significant decreases in WHC, SC and EC of DFC were noticed at the highest temperature (60 °C) for most of the date varieties. The observed influence of drying temperature on functional DFC properties calls for the use of low temperature in order to obtain DFC as suitable food ingredient.     

Guided Mesh Normal Filtering

The joint bilateral filter is a variant of the standard bilateral filter, where the range kernel is evaluated using a guidance signal instead of the original signal. It has been successfully applied to various image processing problems, where it provides more flexibility than the standard bilateral filter to achieve high quality results. On the other hand, its success is heavily dependent on the guidance signal, which should ideally provide a robust estimation about the features of the output signal. Such a guidance signal is not always easy to construct. In this paper, we propose a novel mesh normal filtering framework based on the joint bilateral filter, with applications in mesh denoising. Our framework is designed as a two‐stage process: first, we apply joint bilateral filtering to the face normals, using a properly constructed normal field as the guidance; afterwards, the vertex positions are updated according to the filtered face normals. We compute the guidance normal on a face using a neighboring patch with the most consistent normal orientations, which provides a reliable estimation of the true normal even with a high‐level of noise. The effectiveness of our approach is validated by extensive experimental results.     

Three-dimensional solution structure of beta cryptogein, a beta elicitin secreted by a phytopathogenic fungus Phytophthora cryptogea

Cryptogein belongs to a new family of 10-kDa proteins called elicitins. Elicitins are necrotic and signaling proteins secreted by Phytophthora spp. responsible for the incompatible reaction and systemic hypersensitive-like necroses of diverse plant species leading to resistance against fungal or bacterial plant pathogens. The solution structure of beta cryptogein from Phytophthora cryptogea fungus was determined by using multidimensional heteronuclear nuclear magnetic resonance spectroscopy. A set of 18 structures was calculated using 1360 NOE-derived distance restraints and 40 dihedral angle restraints obtained from 3JHNH alpha couplings. The RMS deviation from the mean structure is 0.87 +/- 0.14 A for backbone atoms and 1.34 +/- 0.14 A for all the non-hydrogen atoms of residues 2 to 98. The structure of beta cryptogein reveals a novel protein fold, with five helices and a double-stranded beta-sheet facing an omega-loop. One edge of the beta-sheet and the adjacent face of the omega-loop form a hydrophobic cavity. This cavity made of highly conserved residues represents a plausible binding site. Residue 13, which has been identified from directed mutagenesis and natural sequence comparison studies as a key amino acid involved in the differential control of necrosis, is surface exposed and could contribute to the binding to a ligand or a receptor. The solution structure is close to the X-ray structure, with slight differences lightly due to the crystal packing.     

Direct physical factors and PGI2 and TXA2 secretions by a human endothelial cell line: in vitro investigation of pressure and shear stress applied independently or in synergy

The direct effect of two types of mechanical stress was measured through the prostacyclin (PGI2) and thromboxane A2 (TXA2) secretions by a confluent monolayer of cells from the EA.hy926 line. Eight values of constant pressure were applied in the gas phase above the culture medium, around atmospheric pressure taken as a control (0 mm Hg), from -500 to +760 mm Hg. Three amplitudes of sinewave modulated pressure (+/- 40; +/- 80; +/- 160 mm Hg) were explored at a frequency of 1 Hz. Modulated pressure (+/- 40 mm Hg) was also applied synergetically to a shear stress generated under steady state conditions by a rectilinear laminar motion of the medium. The cells remained adherent and exhibited unchanged morphology and viability. Constant pressure or depressure increased both PGI2 and TXA2 release but to an extent depending on the pressure value. Under pressure, the PGI2/TXA2 ratio was unchanged, but was higher under depressure, compared to the control. Pressure modulation strongly stimulated the secretion of PGI2 but had no effect on TXA2. Modulation strongly increased the PGI2/TXA2 ratio to a similar extent for the three amplitudes. Pressure-shear synergy enhanced secretion of PGI2 markedly more than shear stress alone, but the level reached was similar to the one induced by pressure modulation. No cumulative effect on the secretion of PGI2 was observed, whereas TXA2 synthesis undergoes a more than cumulative effect. The PGI2/TXA2 ratio remained unchanged under shear alone or under combined shear-pressure modulation but was higher with the modulated pressure alone. These results demonstrate that pressure has an outstanding effect on secretion that may be origin to local disturbances of the vascular system, thus inducing pathologies such as thrombosis or atherosclerosis.     

Genetic algorithms to solve the cover printing problem

Inspired by successful application of evolutionary algorithms to solving difficult optimization problems, we explore in this paper, the applicability of genetic algorithms (GAs) to the cover printing problem, which consists in the grouping of book covers on offset plates in order to minimize the total production cost. We combine GAs with a linear programming solver and we propose some innovative features such as the “unfixed two-point crossover operator” and the “binary stochastic sampling with replacement” for selection. Two approaches are proposed: an adapted genetic algorithm and a multiobjective genetic algorithm using the Pareto fitness genetic algorithm. The resulting solutions are compared. Some computational experiments have also been done to analyze the effects of different genetic operators on both algorithms.