Oxide anodes in electro-organic oxidation. Oxidation of maleic addon tungsten oxide anodes

The electrochemical oxidation of maleic acid on tungsten anodes has been investigated. Glyoxal and carbon dioxide were the main products together with tartaric acid and acetaldehyde. Glyoxal is also obtained as the main product from the oxidation ofd-tartaric acid. Under the same conditions succinic acid is completely oxidized to carbon dioxide and water. The anodic dissolution of tungsten and the oxidation of water to oxygen become predominant in the final stages of the electrolyses.     

Mapping salt-marsh vegetation by multispectral and hyperspectral remote sensing

Tidal marshes are characterized by complex patterns both in their geomorphic and ecological features. Such patterns arise through the elaboration of a network structure driven by the tidal forcing and through the interaction between hydrodynamical, geophysical and ecological components (chiefly vegetation). Intertidal morphological and ecological structures possess characteristic extent (order of kilometers) and small-scale features (down to tens of centimeters) which are not simultaneously accessible through field observations, thus making remote sensing a necessary observation tool. This paper describes a set of remote sensing observations from several satellite and airborne platforms, the collection of concurrent ground reference data and the vegetation distributions that may be inferred from them, with specific application to the Lagoon of Venice (Italy). The data set comprises ROSIS, CASI, MIVIS, IKONOS and QuickBird acquisitions, which cover a wide range of spatial and spectral resolutions. We show that spatially-detailed and quantitatively reliable vegetation maps may be derived from remote sensing in tidal environments through unsupervised (K-means) and supervised algorithms (Maximum Likelihood and Spectral Angle Mapper). We find that, for the objective of intertidal vegetation classification, hyperspectral data contain largely redundant information. This in particular implies that a reduction of the spectral features is required for the application of the Maximum Likelihood classifier. A large number of experiments with different feature extraction/selection algorithms show that the use of four bands derived from Maximum Noise Fraction transforms and four RGBI broad bands obtained by spectral averaging yield very similar classification performances. The classifications from hyperspectral data are somewhat superior to those from multispectral data, but the close performance and the results of the features reduction experiments show that spatial resolution affects classification accuracy much more importantly than spectral resolution. Monitoring schemes of tidal environment vegetation may thus be based on high-resolution satellite acquisitions accompanied by systematic ancillary field observations at a relatively limited number of reference sites, with practical consequences of some relevance.     

Supercritical fluid extraction in sunflower seed technology

Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its protein fraction is also recognised as valuable for human consumption when suitably purified from polyphenols, which negatively affect colour and nutritional value. On this basis, a main research has been developed, with the aim of testing the technical feasibility of a supercritical fluid extraction (SFE) process involving a preliminary supercritical CO₂ (SC‐CO₂) extraction of oil from sunflower de‐hulled seeds, followed by the removal of polyphenols from de‐fatted meal by means of ethanol coupled with SC‐CO₂. The paper reports the experimental protocol followed, together with the kinetics of the extractions, knowledge of which allows the optimisation of working parameters and the determination of process yields.     

Decarbonizing cement plants via a fully integrated calcium looping-molten carbonate fuel cell process: Assessment of a model for fuel cell performance predictions under different operating conditions

This study is part of a comprehensive research devoted to the integration of a Calcium Looping (CaL) process with a Molten Carbonate Fuel Cell (MCFC) for the decarbonisation of a full-scale cement plant. In the proposed process, where the energy intensive oxy-combustion occurring in the CaL calciner is replaced with a conventional combustion in air. The CO₂-rich gas leaving the calciner is injected into the MCFC cathode while the anode side is fuelled by H₂-rich gases produced by a sorption-enhanced reforming (SER) process. The high CO₂-concentrated gas leaving the anode will be sent to valorisation processes and/or the CO₂ final disposal.Here we focus on modelling, simulation and characterization of the MCFC used as a device for CO₂ separation as well as electricity production, here considered as a process by-product. Polarization curves (I–V curves) and Electrochemical Impedance Spectroscopy (EIS) were measured to support the development and the calibration of a semi-empirical model obtained by theoretical consideration.The experimental campaign demonstrated that the fitted model is able to reproduce the real cell performance when varying the temperature, H₂ concentration, CO₂ concentration at anode and cathode respectively as well as CO₂ CaL capture rate.Indeed, the average difference between numerical and experimental results is always below 2%.Results also demonstrated that the MCFC can be usefully considered as an efficient CO₂ concentrator, with a CO₂ fraction at the anode outlet that is greater than 51% on a dry basis.     

Biogas trace compounds impact on high-temperature fuel cells short stack performance

Nowadays the most important issues for commercial SOFC systems are related to their durability and stability of performance both of which are affected by fuel feeding composition. The trace compounds contained in biogenous fuels can interact with SOFC components causing evident drops in performance and severely reducing the lifetime of the entire system. Due to the significant impact on SOFC performance from widely varying fuel inputs, the influence of trace compounds should be investigated in real case studies and practical applications. Anode deactivation and porous blocking electrodes are the main consequences that occur due to the presence of trace compounds impact.This work shows an experimental case study where the anode supported solid oxide fuel cells short stacks are fed with fuels containing trace compounds. These compounds were selected from the biological decomposition of organic matters. In addition, sulphur compounds were selected chlorine, aromatic compounds, terpenes, and carboxyl compounds were selected. The most deleterious impact on the stack was due to the sulphur action. However, chlorine compounds also affected the external part of the cell causing the stack to break due to the corrosion of the sealant.     

Microbiological and technological characterization of sourdoughs destined for bread-making with barley flour

The aim of the present study was the microbiological and technological characterization of laboratory- made sourdoughs for use in barley-flour-based bread-making. A defined multi-strain starter culture consisting of selected lactic acid bacteria (LAB) and yeasts from wheat sourdoughs was inoculated into three flour–water mixtures, composed of: (i) 100% wheat flour (ii) 50% wheat flour and 50% hull-less barley flour (composite flour); (iii) 100% hull-less barley flour. After two months of continuous propagation, the chemical characteristics of the three sourdoughs were investigated by measuring: pH, total titratable acidity and concentrations of various microbial metabolites by HPLC (i.e. lactic, acetic, phenyllactic and butyric acids and diacetyl). The microbial traits were studied through viable counts, isolation and typing of LAB and yeasts and PCR-DGGE analyses. Only Saccharomyces cerevisiae and Lactobacillus plantarum were detectable in the sourdoughs together with other lactobacilli species which were different depending on the type of flour blend used. The molecular typing of the isolates highlighted that only a few strains among those initially inoculated prevailed. The volume increases of the three types of sourdough were also investigated and a correlation was seen between an increase in the barley flour content and a reduction in the dough volume.     

Characterization of multifunctional nanosystems based on the avidin-nucleic acid interaction as signal enhancers in immuno-detection

The Avidin-Nucleic-Acids-Nano-Assembly (ANANAS) is a kind of soft poly avidin nanoparticle originating from the high affinity interaction between avidin and the nucleic acids. In this work we investigated the possibility of transforming ANANAS cores into stoichiometrically controlled multifunctional nanoparticles through a "one-pot" procedure, and we measured in a quantitative way their ability to work as reagents for enhanced immunodiagnostic detection. Initially, we measured the ANANAS loading capability for biotinylated proteins of different nature. About 200 molecules of biotin-horseradish-peroxidase (40KDa b-HRP) and 60 molecules of biotin-immunoglobulin-G (150KDa b-IgG) could be accommodated onto each nanoparticle, showing that steric limitations dictate the number of loadable entities. Stoichiometrically controlled functional assemblies were generated by mixing core particles with subsaturating amounts of b-HRP and b-IgG. When applied as detection reagents in an Enzyme-Linked-ImmunoSorbed-Assay (ELISA), these assemblies were up to two-orders of magnitude more sensitive than commercial HRP-based reagents. Assemblies of different composition displayed different efficacy, indicating that the system functionality can be fine-tuned. Within-assay variability (CV%), measured to assess if the assembly procedure is reproducible, was within 10%. Stability experiments demonstrated that the functionalyzed assemblies are stable in solution for more than one week. In principle, any biotinylated function can be loaded onto the core particle, whose high loading capacity and tunability may open the way toward further application in biomedicine.