Measurements of monomer partitioning in emulsion copolymerization systems

A new apparatus to measure the equilibrium solvent activity in a multiphase system containing a particulated polymer is presented. An experimental procedure to determine the monomer partitioning in typical emulsion copolymerization systems is developed; the method is devised in a way that no phase separation between water and swollen polymer particles is required in order to determine the monomer content in each phase. The analytical technique used is quantitative gas chromatography, either of the vapor or of the liquid phases. Different monomers (styrene, methyl methacrylate, and vinyl acetate) and polymeric matrices (polystyrene and methyl methacrylate–vinyl acetate copolymer) are examined both above and below saturation conditions (corresponding to intervals II and III of an emulsion polymerization process). The experimental results are compared with predictions of a literature model. © 1996 John Wiley & Sons, Inc.     

Characterization of olive oil produced with a new enzyme processing aid

By carrying out olive oil extraction experiments with three olive varieties (Dritta, Coratina, and Leccino), a new processing cytolase enzyme aid was tested. The oils, obtained with the enzyme adjuvant upon extraction, were characterized (with respect to reference oils) by: (i) relatively higher content of natural antioxidants (free and linked phenols, ortho-diphenols, tocopherols), trans-2-hexenal, total aromatic substances, chlorophyllic pigments, and steroid hydrocarbons; (ii) slightly lower content of aliphatic alcohols, triterpene alcohols, triterpene dialcohols, β-sitosterol, and total sterols; (iii) slightly higher values of integral color index, resistance to autoxidation, and global quality indices; (iv) lower values of carotenoid color index, alcoholic index and some qualitative ratios, such as trans-2-hexenal/hexanal, trans-2-hexenal/total aroma, campesterol/stigmasterol; and (v) a higher sensory score. Hence, they exhibited better overall qualitative characteristics. The enzyme adjuvant, in addition, led to higher oil extraction outputs.     

Code Normalization for Self-Mutating Malware

Next-generation malware will adopt self-mutation to circumvent current malware detection techniques. The authors propose a strategy based on code normalization that reduces different instances of the same malware into a common form that can enable accurate detection.     

Sum–product graphical models

Machine Learning - This paper introduces a probabilistic architecture called sum–product graphical model (SPGM). SPGMs represent a class of probability distributions that combines, for the...     

Design of microalgal biomass production in a continuous photobioreactor: An integrated experimental and modeling approach

The industrial production of microalgae in continuous photobioreactors (PBRs) was investigated using an integrated experimental-modeling approach.     

Addition of transition metals to lithium intercalated fullerides enhances hydrogen storage properties

We report an innovative synthetic strategy based on the solid state reaction of fullerene C₆₀ with lithium-transition metals alloys (platinum and palladium), which provides transition metal-decorated lithium intercalated fullerides, with improved hydrogen storage properties. Compounds with Li₆Pt_0.11C₆₀ and Li₆Pd_0.07C₆₀ stoichiometry were obtained and investigated with manometric/calorimetric techniques which showed an 18% increase of the final H₂ absorbed amount with respect to pure Li₆C₆₀ (5.9 wt% H₂) and an improved absorption process kinetic. The absorption mechanism was investigated with X-rays diffraction which allowed to identify the formation of the hydrofullerides. Scanning Electron Microscopy was applied to gain information on transition metal distribution and detected the presence of platinum and palladium aggregates which are shown to perform a surface catalytic activity towards hydrogen molecule dissociation process.     

How probiotics face food stress: They get by with a little help

Abstract

The dietary consumption of probiotics in the form of pharmaceuticals or functional food can improve human health and contribute to disease prevention. However, the biological activity and health potential of food-delivered probiotics can be severely compromised by the stress conditions encountered by the microorganisms throughout the manufacture process, from probiotic preparation to their inclusion into food, subsequent storage and ingestion. Here, we give an account of the stress factors that can have major negative impacts on probiotic viability and functionality, with a focus on food-related environmental adverse conditions. We also describe some of the mechanisms elicited by the microbial cells to counteract these stresses and summarize a few relevant approaches proposed in literature to develop more robust and competitive probiotics by enhancing their stress tolerance, with the aim to improve the efficacy and health value of probiotic functional food.