Electroacoustic and Acoustic Attenuation Spectroscopy as New Tools for In Situ-Monitoring of Metal Oxide Precursor Preparation in Liquid Phase

The in situ-monitoring of a solid synthesis was realised by electroacoustic and acoustic attenuation spectroscopy. These techniques were applied to track the crystal growth of alumina precursor nanoparticles used as model compound. A commercially available set-up with a circular flow detector cell for joint electroacoustic and attenuation measurements was used. Course of zeta potential as well as particle growth was measured during continuous hydrolysis of dry Al-sec-butoxide in isopropanol. Zeta potential shows minima and maxima with increasing water amount, whereas particles start to grow significantly after a defined time of operation. In some experiments the synthesis was stopped ahead of time and the formed solids were additionally studied ex situ by characterisation methods such as solid-state NMR or transmission electron microscopy. Measured ultrasound data can be correlated to elemental processes during particle formation. First experiments on monitoring of synthesis scale-up show potential for future application of this technique.     

Sodium benzoate,potassium sorbate and sodium nitrite as silage additives

BACKGROUND: The hygienic quality of silage is important for animal health, animal production and food quality. The aim of this study was to evaluate the effect of five silage additive mixtures on yeast, mould, and clostridia growth and other silage quality criteria. The additives, composed of sodium nitrite, sodium benzoate and/or potassium sorbate, were used to treat a grass forage crop before ensiling. The silages were compared with untreated silage and silages treated with two commercial additives: Promyr NF (PNF), which is based on formic and propionic acid, and Kofasil Ultra (KU), a mixture of sodium nitrite, sodium benzoate, sodium propionate and hexamine. RESULTS: All tested additives significantly (P < 0.001) reduced butyric acid and ammonia‐N formation in low‐dry‐matter (DM) silages compared to the control. Only KU and the mixtures of 600 g sodium nitrite, 250 g sodium propionate, 750 g sodium benzoate (A1) and 250 g sodium nitrite with 1000 g sodium benzoate and 500 g potassium sorbate (A5) ton^?1 of fresh forage were found to reduce (P < 0.001) the presence of clostridia spores in low‐DM silages. In high‐DM silages, treatments A1, A5 and A2 (250 g sodium nitrite and 1000 g sodium benzoate) contained less (P < 0.02) yeast than the control and PNF, but not KU. All treated silages were aerobically stable. The concentrations of nitrate‐N in all silages and nitrite‐N in low‐DM were below the threshold level for feed at the end of storage. CONCLUSIONS: The additive mixtures A1 and particularly A5 improved silage quality at least to the same extent as commercial products, even though they contained no hexamine and less nitrite. Copyright © 2009 Society of Chemical Industry     

Substitutes for procedural fairness: Prototypical leaders are endorsed whether they are fair or not.

This article extends research on leader procedural fairness as well as the social identity model of leadership effectiveness (SIMOL) by demonstrating that leader prototypicality can act as a substitute for procedural fairness. Although procedural fairness in general and voice in particular have been found to have a robust positive influence on leader endorsement, the authors showed in an experimental scenario study and a correlational field study that the influence of voice on leader endorsement is substantially reduced when leaders are perceived as prototypical for the group that they lead and followers are highly identified with their group. Additionally, supportive of predictions of the SIMOL, leader prototypicality interacted with follower identification in predicting leader endorsement, such that prototypicality had a positive effect on leader endorsement, which was enhanced among high identifiers. Overall, these results suggest that leaders who are attuned to their followers' group identity can afford to go it alone, for the better or the worse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of external stress and plastic strain on morphological evolution of precipitates in Ni-based superalloys

An analytical method is proposed to investigate the morphological evolution of γ^′ precipitates in Ni-based superalloys. Two types of superalloys are considered with different ratio between the Young’s moduli of the precipitates and the matrix. Based on Eshelby’s equivalent inclusion theory and Mori–Tanaka’s mean field method the elastic energy is calculated as a function of the particle shape. The plastic strain induced by the formation of dislocation networks at the phase interface is taken into account. The results show that the external stress and the plastic matrix strain play a significant role for shape stability and the rafting mechanism of the precipitates. The elastic–plastic analysis provides a satisfactory explanation for all available experimental observations superalloys undergoing plastic creep.     

Cationic surfactants in laundry detergents and laundry aftertreatment aids

Cationic surfactants have a positively charged nitrogen atom and at least one hydrophobic, long-chain substituent in the molecule. Because of their fabric-softening and antistatic properties, they are used as active materials in fabric-softening agents. Suitable cationic surfactants are mostly quaternary ammonium salts, and to a lesser extent, imidazolinium salts with two long hydrophobic alkyl chains. Alkylated, partly ethoxylated polyamines, amine amides, ester amines and di-quaternary compounds also have recently been used or proposed. Fabric softeners generally are aqueous dispersions of distearyl dimethyl ammonium chloride or tallow alkylated imidazolinium derivatives in concentrations of 1–9%. Concentrated fabric softeners have recently been pushed into the market as double, triple or 10-fold concentrates. Fabric softeners used in the forms of acrosol sprays, pads or sheets, are not used in the washing machine but can be used in the laundry dryer. The combination of laundry detergent and fabric softener is a single product is impaired by anionic surfactants normally contained in laundry detergents because they react with the cationics to form neural salts. With the so-called soft detergents, one attempts to circumvent these difficulties by means of special formulations, e.g., with nonionics or by using definite physical-chemical mechanisms. They represent a compromise with regard to detergency performance and softening effect.     

Characterisation of sugar beet pectin fractions providing enhanced stability of anthocyanin-based natural blue food colourants

The bathochromic effect resulting from the addition of sugar beet pectin (SBP) to black currant juice, purified anthocyanins (ACN-E) and purified polyphenol extracts comprising both anthocyanins and non-anthocyanin phenolics (PP-E), respectively, were monitored by VIS spectroscopy at varying pH relevant to food formulations (pH 3.6–5.0). Furthermore, a low molecular pectic polysaccharide fraction (PPF) was isolated from SBP using 70% aqueous 2-propanol and further characterised with respect to its chemical composition and mineral content. The marked bathochromic effect was found to be due to the formation of anthocyanin–metal chelate complexes. Only at pH 5.0 SBP entailed a moderate bathochromic shift of 12 nm in model solutions containing ACN-E. This effect was enhanced in PPF model solutions resulting in a λ_max shift up to 50 nm, bringing about an intense blue colour. The bathochromic shift was boosted with increasing pH and upon purification of the anthocyanins. In contrast, after SBP and PPF addition to black currant juice, the bathochromic effect was almost annihilated. Model solutions were stored at 20 °C in the dark for 12 days, and optimum stability of the blue colour was observed at pH 5.0.     

Real-time multiplex PCR: An accurate method for the detection and quantification of 35S-CaMV promoter in genetically modified maize-containing food

A very sensitive and new real-time multiplex PCR method for the quantification of genetically modified (GM) maize crops in food materials was developed and validated for an ABI Prism 7700 Sequence Detection System. In the assay described, fluorescence-labelled TaqMan probes were chosen to detect the amplified DNA fragments during PCR. In this multiplex approach, maize-specific DNA (zein) and 35S-CaMV promoter-specific DNA fragments are amplified in the same tube. The method was tested for the detection and quantification of the four maize events that are approved in Europe and contain the 35S-CaMV promoter: Bt11, Bt176, Mon810 and T25 maize. Quantification was based on a standard curve prepared from certified maize flour reference material prepared by the Institute for Reference Materials and Measurements. Quantification within the range of the standard curve (0.05-1% GM maize) and up to 100% was possible. Repeatability of the method for each GM maize event was determined; coefficients of variations ranged from 28-40%. In addition, three internal Nestlé laboratories successfully applied this method and comparable results were obtained.     

Modelling of hot-carrier degradation and its application for analog design for reliability

An analytical CMOS transistor ageing model is presented and a new procedure that allows the extraction of its parameters are presented in this paper. Then, we show how this model can be used to forecast and understand the drifts of the main characteristics of a CMOS circuit. Further, we demonstrate that this model can also be used to help the analog designer to choose and/or modify a circuit in order to minimise the hot-carrier induced degradations. Finally, we use an ageing simulation tool realised in VHDL-AMS to validate the analytical study, and we present our first experimental results.     

Load prediction method for heat and electricity demand in buildings for the purpose of planning for mixed energy distribution systems

Energy planning for mixed energy distribution systems is important to increase the flexibility in the regional and national energy systems. Expected maximum loads, load profiles and yearly energy demands, all divided into heat and electricity purposes, are important input parameters to plan for the most economical, technical and environmental optimal energy distribution system for a planning area. First, this article presents a load prediction method which estimates heat and electricity load profiles for various building categories. The method is based on statistical analyses of hourly simultaneous measured district heat and electricity consumption in several buildings, as well as background information of the measured buildings. The heat load model is based on regression analyses, whereas the electricity load model is based on various statistical distributions. Second, a method for load aggregation based on the building categories’ load profiles is presented to estimate the maximum load demands, yearly load profiles, load duration profiles and yearly energy demands, all divided into heat and electricity purposes, for a planning area.