Carbonation of steel slag for CO2 sequestration: leaching of products and reaction mechanisms

Carbonation of industrial alkaline residues can be used as a CO2 sequestration technology to reduce carbon dioxide emissions. In this study, steel slag samples were carbonated to a varying extent. Leaching experiments and geochemical modeling were used to identify solubility-controlling processes of major and trace elements, both with regard to carbonation mechanisms and the environmental properties of the (carbonated) steel slag. Carbonation was shown to reduce the leaching of alkaline earth metals (except Mg) by conversion of Ca-phases, such as portlandite, ettringite, and Ca-(Fe)-silicates into calcite, possibly containing traces of Ba and Sr. The leaching of vanadium increased substantially upon carbonation, probably due to the dissolution of a Ca-vanadate. The reactive surface area of Al- and Fe-(hydr)oxides increased with the carbonation degree, which tends to reduce the leaching of sorption-controlled trace elements. Sorption on Mn- (hydr)oxides was found to be required to adequately model the leaching of divalent cations, but was not influenced by carbonation. Consideration of these three distinct reactive surfaces and possible (surface) precipitation reactions resulted in adequate modeling predictions of oxyanion and trace metal leaching from (carbonated) steel slag. Hence, these surfaces exert a major influence on the environmental properties of both fresh and carbonated steel slag.     

Beer quality screening by FT-IR spectrometry: Impact of measurement strategies, data pre-processings and variable selection algorithms

In the presented research three measurement strategies of Fourier transform infrared (FT-IR) spectrometry (horizontal- and micro-attenuated total reflection (HATR and μATR, respectively) and a novel high throughput transmission (HTT)) in combination with extensive chemometric approach have been applied for analysis of beer. Fifty Belgian beer samples were analyzed: lager and white beers, dark and blonde ales, lambic and Trappist beers. Partial least square (PLS) regression was used for prediction of different physicochemical parameters of beer based on mid-IR data, modified with different spectral preprocessing and variable selection algorithms for higher prediction performance. It was found that HATR and μATR have the same prediction capability with a slight advantage of μATR and excellent correlations between spectra and reference values were demonstrated for original (R² 0.95), apparent (R² 0.89) and real (R² 0.95) extracts, real and apparent degrees of fermentation (R² 0.91 and 0.89), alcohol content (R² 0.94) and energetic value (R² 0.95). Good results (R² 0.83) were obtained from the HTT experiments for prediction of real extract and allow measurement of large sample numbers in short time (1 sample/minute) with further potential increase in a sample throughput and has the possibility for automation. The obtained results indicate that mid-IR spectrometry in combination with advanced pre-processing and variable selection methods is a valuable analytical tool for high throughput measurement of beer quality attributes and thus has potential for use in product development and quality control.     

Cloning, characterization and functionality of the orotidine-5'-phosphate decarboxylase gene (URA3) of the glycolipid-producing yeast Candida bombicola

Candida bombicola is a yeast species known to synthesize glycolipids. Although these glycolipids find several industrial, cosmetic and pharmaceutical applications, very little is known about the genetics of C. bombicola. A basic tool for genetic study and modification is the availability of an efficient transformation and selection system. In order to develop such a system, the URA3 gene of Candida bombicola was isolated using degenerate PCR and genomic walking. The gene encodes for an enzyme of 262 amino acids and shows high homology with the known orotidine-5'-phosphate decarboxylases of several other yeast species. The functionality of the gene was proved by complementation of a URA3-negative Saccharomyces cerevisiae strain.     

Effect of water and monoglyceride concentration on the behaviour of monoglyceride containing fat systems

The effect of water and monoglycerides on the structural behaviour of a selected fat system was investigated to explore their role in structure development of products like margarine and sponge cake. Firstly, the monoglyceride and triglyceride system was selected based on solid fat content (SFC) determination. This system was further investigated by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). Secondly, the role of water concentration in this system was investigated by SFC-determination and hardness measurements at different water concentrations. These investigations demonstrate clearly the important role of water, especially at lower concentrations. Finally, the influence of monoglycerides on droplet size distribution in margarines and on textural properties of sponge cakes was investigated. These investigations reveal a larger droplet size of monoglyceride containing margarines and a more dense and harder texture of sponge cakes containing monoglycerides.     

Nuclear power,climate change and energy security: Exploring British public attitudes

Public attitudes towards nuclear power in the UK have historically been deeply divided, but as concern about climate change and energy security has exerted an increasing influence on British energy policy, nuclear power has been reframed as a low-carbon technology. Previous research has suggested that a significant proportion of people may ‘reluctantly accept’ nuclear power as a means of addressing the greater threat of climate change. Drawing on the results of a national British survey (n=1822), the current study found that attitudes towards nuclear remain divided, with only a minority expressing unconditional acceptance. In general, people who expressed greater concern about climate change and energy security and possessed higher environmental values were less likely to favour nuclear power. However, when nuclear power was given an explicit ‘reluctant acceptance’ framing – allowing people to express their dislike for nuclear power alongside their conditional support – concerns about climate change and energy security became positive predictors of support for nuclear power. These findings suggest that concern about climate change and energy security will only increase acceptance of nuclear power under limited circumstances—specifically once other (preferred) options have been exhausted.     

Enhanced test methods to characterise automotive battery cells

This article evaluates the methods to characterise the behaviour of lithium ion cells of several chemistries and a nickel metal hydride cell for automotive applications like (plug-in) hybrid vehicles and battery electric vehicles. Although existing characterisation test methods are used, it was also indicated to combine test methods in order to speed up the test time and to create an improved comparability of the test results. Also, the existing capacity tests ignore that cells can be charged at several current rates. However, this is of interest for, e.g. fast charging and regenerative braking. Tests for high power and high energy application have been integrated in the enhanced method. The article explains the rationale to ameliorate the test methods. The test plan should make it possible to make an initial division in a group of cells purchased from several suppliers.