Numerical assessment of springback for the deep drawing process by level set interpolation using shape manifolds

In this paper, we introduce an original shape representation approach for post-springback characterization based on the automatic generation of parameterized level set functions. The central idea is the concept of the shape manifold representing the design domain in the reduced-order shape-space. Performing Proper Orthogonal Decomposition on the shapes followed by using the Diffuse Approximation allows us to efficiently reduce the problem dimensionality and to interpolate uniquely between admissible input shapes, while also determining the smallest number of parameters needed to characterize the final formed shape. We apply this methodology to the problem of springback assessment for the deep drawing operation of metal sheets.     

Real-time infinite horizon tracking with data fusion for augmented reality in a maritime operations context

In this paper, we propose a method for real-time horizon tracking (i.e., separation line between the sky and the sea) in a maritime operations context. We present the fusion of an image processing algorithm with the data obtained from the inertial measurement unit (IMU). The initial aim is to filter out environmental conditions using inertial information in order to combine a video stream with onboard electronic charts. This is achieved by the detection of the horizon with an image processing algorithm in an area defined by the IMU. We then present an evaluation of the algorithm with regard to the rate of detection of the horizon and the impact of the image resolution on the computational time. The purpose of developing this method is to create an augmented reality maritime operations application. We combine the video stream with electronic charts in a single display. We use the position of the horizon in the image to split the display into different areas. Then, we use transparency to display the video, the electronic charts or both.     

Identification,Synthesis, and Behavioral Activity of 5,11-Dimethylpentacosane,A Novel Sex Pheromone Component of the Greater Wax Moth,Galleria Mellonella (L.)

The greater wax moth, Galleria mellonella (L.), is a serious and widespread pest of the honeybee, Apis mellifera L. In contrast to most moths, for which long-range mate finding is mediated by female-produced sex pheromones, G. mellonella males attract conspecific females over long distances by emitting large amounts of a characteristic scent in combination with bursts of ultrasonic calls. The male scent for this species was previously identified as a blend of nonanal and undecanal. When these compounds were bioassayed, characteristic short-range sexual behavior, including wing fanning, was triggered in conspecific females, but the aldehyde blend failed to elicit attraction over longer distances. We identified, via analysis and synthesis, a third male-specific compound, 5,11-dimethylpentacosane. We show that it acts as a behavioral synergist to the aldehydes. In wind tunnel experiments, very few female moths responded to the aldehyde blend or to 5,11-dimethylpentacosane tested separately, but consistently showed orientation and source contact when a combination of all three compounds was applied. The level of attraction to the three-component mixture was still lower than that to male extract, indicating that the composition of compounds in the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. The identification of 5,11-dimethylpentacosane is an important step for the development of an efficient long-range attractant that will be integrated with other environmentally safe strategies to reduce damage to beehives caused by wax moths.     

Physical aging in polymers: Comparison of two ways of determining narayanaswamy's parameter

In this work, we have investigated by differential scanning calorimetry the enthalpy relaxation of two poly[methyl(α-n-alkyl)acrylates] in which it is possible to change the length of the two alkyl chains. In particular, we have evaluated the Narayanaswamy parameter, which controls relative contribution of temperature and of structure to the relaxation times, by two methods: Grenet's method (GM) and the peak-shift method (PSM). The data obtained show that both methods lead to equivalent results. Nevertheless, PSM requires fewer experiments than GM, and PSM appears to be more practical. The results obtained on the two acrylates show that the parameter x increases with the lateral chain length, that is to say, that the temperature effects increase as the length of the alkyl chain is increased.     

Application of ATR-FTIR for a rapid and simultaneous determination of sugars and organic acids in apricot fruit

A simple, fast and accurate Fourier transform mid-infrared spectroscopy method was developed for simultaneously determining sugar and organic acid contents in apricot fruit slurries using the attenuated total reflectance. The potential of this method coupled with chemometric techniques based on partial least squares was assessed by comparison with currently used enzymatic determination of sucrose, glucose, fructose, malic acid and citric acid. Fruits of eight contrasted cultivars harvested at different ripening stages were used in this study and randomly divided in a calibration set (505 apricots) and in a validation set (252 apricots). The most suitable region was found in the range between 1500 and 900 cm⁻¹. Good prediction performances were obtained (R² ? 0.74 and RMSEP ? 18%). Results concerning the prediction of other quality traits such as firmness, skin colour, ethylene production, soluble solids content and titratable acidity were discussed.     

Effect of freezing treatments and yeast amount on sensory and physical properties of sweet bakery products

The frozen bakery market has grown significantly in developed countries over the past decade.     

Rapid and non-destructive analysis of apricot fruit quality using FT-near-infrared spectroscopy

A non-destructive optical method based on near-infrared spectroscopy has been used for the evaluation of apricot fruit quality. Diffuse reflectance measurements (800–2500 nm), physical, physiological and biochemical measurements were performed individually on 877 apricot fruits from eight contrasted cultivars harvested at different ripening stages. Relationships between spectral wavelengths and quality attributes were evaluated by application of chemometric techniques based on partial least squares (PLS) on fruit set divided randomly into two groups: 598 fruits for calibration and 279 for validation. Good prediction performance was obtained for soluble solids and titratable acidity with correlation coefficients of 0.92 and 0.89 respectively and root mean square errors of prediction of 0.98% Brix and 3.62 meq 100 g⁻¹ FW respectively. For the other quality traits such as firmness, ethylene, individual sugars and organic acids, the prediction models were not satisfactorily accurate due to the high error of calibration and prediction.     

Comparing Al-SBA-15 Support and Pt/Al-SBA-15 Catalyst: Changes in Al Speciation and Acidic Properties Induced by the Introduction of Pt via Aqueous Medium

Differences between the acidic properties of silicoaluminic Pt-containing catalysts and those assessed on their parent supports have been reported in the literature and attributed to the presence of the metal nanoparticles and to their influence on the acid sites. It is shown here that for mesoporous materials containing various types of Al species, an alternative explanation can be proposed. ²⁷Al NMR spectroscopy, FTIR of adsorbed CO and probe catalytic tests suggest the redistribution of aluminium atoms upon contact of the parent support with the aqueous solution containing the Pt precursor. Upon contact with water and thermal treatment, strong and mild Brønsted sites (Si–O(H)–Al) transform into strong Lewis sites (isolated tetracoordinated Al atoms). As a consequence, it may not be straightforward to deduce the acidic properties of metal-containing catalysts supported on Al-containing mesoporous materials from those of the bare support, because the surface species may differ significantly.