Color image simulation for underwater optics

Underwater optical image simulation is a valuable tool for oceanic science, especially for the characterization of image processing techniques such as color restoration. In this context, simulating images with a correct color rendering is crucial. This paper presents an extension of existing image simulation models to RGB imaging. The influence of the spectral discretization of the model parameters on the color rendering of the simulated images is studied. It is especially shown that, if only RGB data of the scene chosen for simulations are available, a spectral reconstruction step prior to the simulations improves the image color rendering.     

Fingerprinting Biogenic Aldehydes through Pattern Recognition Analyses of Excitation–Emission Matrices

Biogenic carbonyls, especially aldehydes, have previously demonstrated their potential to serve as early diagnostic biomarkers for disease and injury that have not been fully realized owing, in part, to the lack of a rapid and simple point-of-care method for aldehyde identification. The ability to determine which carbonyl compound is elevated and not just the total aldehydic load may provide more disease- or injury-specific diagnostic information. Toward this end, a novel fluorophore is presented that is able to form a complex with biogenic carbonyls under catalyst-free conditions so as to give a fluorescent fingerprint of the resulting hydrazone. The successful identification of bound carbonyls was accomplished with a newly described algorithm that applied principal curvature analysis of excitation–emission matrices to reduce surface features to ellipse representations, followed by a pattern-matching routine. With this algorithm, carbonyls were identified over a range of concentrations, and mixture components were successfully parsed. Overall, the results presented lay the groundwork for novel implementations of chemometrics to low-cost, rapid, and simple-to-implement point-of-care diagnostics.     

Contribution of C. beijerinckii and C. sporogenes in association with C. tyrobutyricum to the butyric fermentation in Emmental type cheese

The relationship between C. tyrobutyricum, C. sporogenes and C. beijerinckii in experimental cheese conditions, and their influences on late-blowing and butyric fermentation, have been investigated. A molecular approach using a PCR-TTGE method in combination with conventional methods, such as microbiological and physico-chemical analysis, was performed to monitor the evolution of these clostridial species, simultaneously with the occurrence of cheese defects. Sixteen Emmental type cheeses were produced from milk inoculated with different clostridial spore associations. In all cheeses inoculated with C. tyrobutyricum, obvious signs of late blowing were detected. In cheeses inoculated with C. beijerinckii or C. sporogenes, a formation of holes in cheese body was observed, with a concomitant slight amount of butyric acid production. Even though C. beijerinckii and C. sporogenes were less metabolically active and less numerically important than C. tyrobutyricum in cheese as shown by TTGE profiles, the association of these species to C. tyrobutyricum enhanced the butyric fermentation and the cheese defects. The level of butyric content in ripened cheese increased to 268 mg 100 g(-1) in presence of C. tyrobutyricum, and reached a maximum of 414 mg 100 g(-1) in presence of the C. beijerinckii-C. tyrobutyricum (1:10) association. The propionic fermentation was also higher in cheese inoculated with C. tyrobutyricum, and was slowed down in presence of C. beijerinckii and C. sporogenes. From 30 days of ripening, a strong correlation between the chemical contents and the intensity of cheese defects was demonstrated. A chemical analysis of cheese associated with a molecular method for microbial spoilage investigation allows the prediction of the level of late blowing at early stages of ripening, and the understanding of the origin of the defect.     

Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction,Global Yield,Extraction Kinetics,Chemical Composition and Cost of Manufacturing

The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil) and non-food (bio fuel) applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS) simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols). Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF) as alternative solvent compared to hexane as petroleum solvent.     

Relevance and costs of large scale underground hydrogen storage in France

The study analyzes the techno-economic feasibility and business case of large-scale hydrogen underground storage in France. Potential regions for locating the storage cavity were assessed, as well as the anticipated hydrogen demand and renewable energy developments. The business case of salt caverns storage facility has been assessed both in 2025 and 2050, looking at several demand sectors, including mobility (FCEVs), hydrogen-consuming industries and what is defined as “Power-to-Gas”. The hourly operation of the cavern has been modeled. The electricity supply is restricted to wind and grid electricity only.The mobility market is clearly the key driver, both in quantity and economic terms, with an easier to achieve target cost (€4/kgH2, ex-storage). High utilization rates of electrolysers are necessary to reach profitability. A need for massive storage begins for a renewable penetration rate of 50%. The hydrogen costs varies from €4.5/kg to €6.6/kg H2, and the underground mass storage cost remains always under 5% of the overall costs.