Volatile compounds and bacterial community dynamics of chestnut-flour-based sourdoughs

The aims of this study were the monitoring of the microbial dynamics by means of a polyphasic approach based on conventional isolation techniques and PCR-DGGE-based methods in different chestnut-based sourdoughs and the evaluation of the impact of fermentation on volatile organic compounds formation during sourdoughs ripening. Members of the Lactobacillus plantarum group and Pediococcus pentosaceous dominated the sourdough ecosystems. Nevertheless, RAPD-PCR allowed recording a relevant genotypic biodiversity among strains coming from gluten-free flour combinations. Volatile compounds were characterised by GC/MS. A total of 59 volatile compounds were identified, mainly alcohols, esters, acids, aldehydes and ketones. Principal component analysis of samples at the beginning and at the end of ripening offered a good separation of the samples and highlighted the effect of fermentation on the sensorial profile.     

Production of functional probiotic, prebiotic, and synbiotic ice creams

In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.     

Global Asymptotic Stabilization of a Spinning Top With Torque Actuators Using Stereographic Projection

The dynamical equations for a spinning top are derived in which theorientation is specified by a complex variable using stereographic projectionof Poisson's equations. Necessary and sufficient conditions for Lyapunovstability of the uncontrolled motion of the spinning top are derived usingthe Energy-Casimir method. Control laws that globally asymptoticallystabilize the spinning top to the sleeping motion using two torque actuatorsare synthesized by employing techniques from the theory of systems in cascadeform and generalized using Hamilton-Jacobi-Bellman theory with zero dynamics.In short, this paper provides a nice example where the interplay betweendynamics and control leads to elegant and powerful results.     

Building trust in virtual teams

This paper presents a study of trust development in online courses. It reviews the concept of swift trust and examines changes in faculty roles as professors go online. An exploratory content analysis looks at indicators of the development of swift trust in the highest rated of a large number of online courses studied over a three year period, and contrasts these results with one of the poorest rated online courses. Establishing swift trust at the beginning of an online course appears to be related to subsequent course success. Strategies for trust formation are also suggested.     

Board-level multiterminal net assignment for the partial cross-bar architecture

This paper presents a satisfiability-based method for solving the board-level multiterminal net routing problem in the digital design of clos-folded field-programmable gate array (FPGA) based logic emulation systems. The approach transforms the FPGA board-level routing task into a Boolean equation. Any assignment of input variables that satisfies the equation specifies a valid routing. We use two of the fastest Boolean satisfiability (SAT) solvers: Chaff and DLMSAT to perform our experiments. Empirical results show that the method is time-efficient and applicable to large layout problem instances.     

Shelf life of fresh sausages stored under modified atmospheres

The aim of this study was to investigate differences in modified atmosphere packaging (MAP) for the improvement of the shelf life of fresh meat products. Three different conditions for preserving fresh sausages were tested: MAP1 (20% CO2, 70% O2, and 10% N2), MAP2 (40% CO2 and 60% O2), and MAP3 (40% CO2, 30% O2, and 30% N2). Samples from the MAP2 group had fewer spoilage bacteria, stable red color (no change of a* value), and good physical attributes (high water-holding capacity, little loss from cooking, and low shear force needed for cutting) compared with samples from other treatment groups. Thus, high concentrations of CO2 (40%) and O2 (60%) resulted in a longer shelf life for fresh sausages.     

Evaluation of smectite clays as nanofillers for the synthesis of nanocomposite polymer electrolytes for fuel cell applications

Synthetic and natural smectite clays, with different structural and physical parameters, were tested as nanofillers for the creation of Nafion nanocomposites. The solution intercalation method has been successfully applied for incorporation of layered materials into the polymer, while the effect of the solvent, temperature and filler loading were examined in order to determine the optimum conditions for the preparation of highly homogeneous composites.     

A review on aqueous gelcasting: A versatile and low-toxic technique to shape ceramics

This review aims to provide a comprehensive survey of recent low-toxic approaches used in the gelcasting process. In recent years, several natural gelling agents have been developed as possible alternatives to acrylamide systems, which were previously used extensively but are now rarely employed owing to their neurotoxicity.This work collects some successful case studies on aqueous gelcasting based on low-toxic or non-toxic gel-formers that have been applied to produce both dense and porous ceramics. Major innovations in the development of nanocomposite materials, transparent ceramics and microstructurally graded materials are discussed as well.     

Sorption thermodynamics of organic pollutants onto zeolitic tuff: Isosteric and standard enthalpy

The isotherms of sorption of six organic pollutants (benzyl alcohol, phenol, cyclohexanol, o-xylene, toluene and cyclohexane) from water solutions onto a zeolitic tuff (Si/Al ratio = 2.4) have been determined by batch experiments at 4; 14; 24 and 34C. Sorbitivity (amount of solute sorbed per unit dry mass sorbent at the equilibrium) was very low for all molecules tested, particularly so for the hydroxyl compounds. Comparison of Freundlich parameters and the values of isosteric and standard enthalpy as determined in the present study with analogous data for immobilized humic acid and humic acid-zeolite adducts confirms that the sorbing properties of the adducts are not the sum of its components.