Probiotic foods: consumer perception and attitudes

The objective of this study was to evaluate the perception and the attitudes towards probiotic foods of the population in the city of Rio de Janeiro, Brazil. Four hundred and twenty (100.0%) people were interviewed in small-, medium- and large-sized supermarkets located in various parts of the city of Rio de Janeiro. One hundred and twenty-two (29.05%) people defined probiotic foods correctly. Ninety-one (21.67%) were unable to mention a single example of a probiotic food. The results of this study indicate the need for an elementary easy-to-understand educational programme using accessible language in order to fix the concepts related to these products.     

On the reaction mechanism of the chemical activation of Quercus Agrifolia char by alkaline hydroxides

Activation of Quercus Agrifolia char with NaOH and KOH using a rotary batch reactor is presented in this work. Several samples of activated carbon showing a very high degree of activation with predominance of microporosity were obtained. Nitrogen and argon were used as gaseous media in the activation procedure. Samples were evaluated using nitrogen adsorption applying BET and DR equation for porosity assessment. The existence of CN⁻ in activated samples suggests the occurrence of not previously reported chemical reactions in this process and could be an indication of the involvement of N₂ in the chemical reaction. Following these results, some additional chemical reactions are proposed as part of the reaction mechanism for MeOH-C-N₂ system.     

Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.)

BACKGROUND: Horseradish plants (Armoracia rusticana) contain high concentrations of glucosinolates. Former studies have revealed that Armoracia plants cultivated in vitro have markedly lower glucosinolate concentrations than those grown in soils. Yet, these studies neglected that the sulfate concentration in the growth medium may have had a strong impact on glucosinolate metabolism. Accordingly, in this study horseradish in vitro plants were cultivated with differing sulfate concentrations and the glucosinolate concentrations were quantified by ion pair HPLC. RESULTS: Cultivation in 1.7 mmol L^?1 sulfate (as used in the prior studies) resulted in the accumulation of 16.2 µmol g^?1 DW glucosinolates, while the glucosinolate concentration increased to more than 23 µmol g^?1 DW when 23.5 mmol L^?1 sulfate was used in the medium. Correspondingly, the glucosinolate concentration decreased to 1.6 µmol g^?1 DW when sulfate concentration was lowered to 0.2 mmol L^?1. CONCLUSION: Since the glucosinolate accumulation in relation to the sulfate concentration follows a typical saturation curve, we deduce that the availability of sulfate determines the glucosinolate concentration in horseradish in vitro plants. © 2012 Society of Chemical Industry     

15—INTERACTIVE COMPUTER-ASSISTED DESIGN OF CIRCULAR WEFT-KNITTING MACHINES

An interactive computer system used for the visualization of a circular weft-knitting-machine head is described. The system consists of a series of computer packages, which the designer, sitting at the graphics display, uses to build up progressively information describing the weft-knitting machine. The computer packages use Fortran and the graphics language GINO–F and were designed by using a Digital Equipment Corporation PDP 10 computer. One of the most significant advantages of the system is that it enables the machine designer to change the display quickly, for example, to alter positions of the thread guide or the stitch draw. It is also possible to have a display of resulting yarn tensions that occur as the needle passes through the knitting cycle. Work is proceeding to develop the system to generate tapes for numerically controlled machining of the knitting cams.     

Design of robust and ductile FRP structures incorporating ductile adhesive joints

A design concept for engineering structures consisting of brittle FRP components and ductile adhesive joints is proposed. The elastoplastic adhesive joints provide system ductility that compensates for the material ductility that FRP composites lack. In the elastic phase, the adhesive offers sufficient stiffness to provide continuity of stiffness over the joint, thus meeting the short- and long-term serviceability requirements for the structure. In the plastic phase, the adhesive develops a uniform stress distribution along the overlap length, thereby enabling sufficient joint rotation to provide an internal force redistribution that increases structural safety and robustness. The application of the design concept to a two-span FRP beam system with an elastoplastic hinge at mid-support showed an increase in structural robustness of almost 140% compared to a continuous FRP beam. FRP structures designed according to the proposed concept exhibit much higher structural safety than brittle structures without force-redistribution capacity.     

In situ Mechanical Testing Reveals Periodic Buckle Nucleation and Propagation in Carbon Nanotube Bundles

Uniaxial compression studies are performed on 50‐µm‐diameter bundles of nominally vertical, intertwined carbon nanotubes grown via chemical vapor deposition from a photolithographically defined catalyst. The inhomogeneous microstructure is examined, demonstrating density and tube orientation gradients, believed to play a role in the unique periodic buckling deformation mechanism. Through in situ uniaxial compression experiments it is discovered that the characteristic bottom‐to‐top sequential buckling proceeds by first nucleating on the bundle surface and subsequently propagating laterally through the bundle, gradually collapsing the entire structure. The effects of strain rate are explored, and storage and loss stiffnesses are analyzed in the context of energy dissipation.