Use of Micronized Polyethylene Terephthalate (Pet) Waste in Asphalt Binder

The increase in living standards and social and economic development over the past three decades has increased the demand of waste discarded in the environment. In the last five years due to the widespread application of polyethylene terephthalate (PET) waste, improper disposal has become a serious problem in the maintenance of an environmental balance. Some additives have been developed during the last decades in order to improve the mechanical properties of asphalt binder according the rheological properties. This research aims to evaluate the implementation of PET in a modified binder. PET was mixed with the percentage of 4, 5, and 6 wt% within a binder. It was found that progressive addition PET increased pulp consistency and improved its elastic response. Addition of PET showed promise in antiaging action, as the higher oxidation levels decrease modified binders.     

Using two servovalves to improve pneumatic force control in industrial cylinders

Pneumatic actuation systems present several advantages like low cost, high force/volume ratios, and the absence of significant heat or magnetic field generation. However, its use in complex control tasks is hindered by their highly nonlinear behavior. This drawback is caused not only by the nonlinear behavior of phenomena like friction but also by the large variation of some of the system proprieties with the system state. One of such proprieties is the fluidic stiffness of the actuator, which may suffer significant changes with the piston velocity when the pressure dynamics of both actuator chambers are coupled due to the use of only one servovalve. This dependency can be eliminated if the pressure (or pneumatic force) inside each chamber is independently controlled using two servovalves. In this paper, two pneumatic force allocation strategies are proposed and analyzed. In the first one, the stiffness of the actuator becomes independent of the pneumatic force reference. In the second one, the pneumatic forces are devised to avoid early pressure saturation of the cylinder chambers. Based on an experimental test rig, both strategies are compared against each other and against the use of only one servovalve.     

Closed‐loop MIMO transceiver with space–time multilayer transmit selection

A closed‐loop multiple‐input multiple‐output (MIMO) transceiver combining space–time multilayer precoding and transmit selection is proposed. The transmitter design consists in optimizing the number of space–time transmit layers as well as the partitioning of the transmit antennas into the selected number of space–time layers. We show that this problem can be translated into jointly selecting, from a finite alphabet, two transmit matrices that define, respectively, the multilayer space–time code and the antenna mapping to be used. The parametrization of the proposed design takes into account all possible space–time layering schemes in between spatial multiplexing and transmit diversity for a fixed number of transmit antennas and linear precoder structure. Sufficient conditions for solution existence using a linear space–time zero forcing receiver are discussed. Simulation results compare the proposed transceiver with some MIMO schemes and corroborate the benefits of closed‐loop multilayer selection in terms of capacity and bit error rates. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of Probiotic Lactobacillus gasseri Strains of Breast-Fed Infant in a Murine Model

The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival in the gastrointestinal tract, and it has been associated with a variety of probiotic activities and roles, including the reduction of fecal mutagenic enzymes, the production of bacteriocins and the stimulation of macrophages immunomodulation. The aim of the study was to evaluate the effects of a pool of L. gasseri strains isolated from the feces of breastfed infants added in the human milk of healthy women. The milk was both pasteurized and unpasteurized, to verify the cell cytotoxicity of macrophages and to quantify the production of immunologic mediators such as IL-4, IL-6, IFN-γ, TNF-α, NO and oxygen intermediary compounds （H2O2）. The administration of raw human milk and pasteurized human milk to infants is a regular, encouraged practice in units of intensive therapy （UITs） and our present investigation verified the beneficial effect of addition of a pool of L. gasseri to pasteurized human milk （PHML）. Our results show that probiotic supplementation helped to maintain cell viability, reduced IL-6 and IFN-γ production and stimulated TNF-α, NO, H2O2, IL-4 production. Nevertheless, the results indicate that the addition of lactobacillus to human milk was not a determinant in the production of TNF-α. L. gasseri added to breast milk did not present a cytotoxic risk, and the addition ofL. gasseri to pasteurized milk of human milk bank would benefit newborns that depend on milk banks for the colonization of more desirable microbiota.     

Simultaneous determination of bisphenol A and bisphenol B in beverages and powdered infant formula by dispersive liquid-liquid micro-extraction and heart-cutting multidimensional gas chromatography-mass spectrometry

The purpose of this study was to establish a reliable, cost-effective, fast and simple method to quantify simultaneously both bisphenol A (BPA) and bisphenol B (BPB) in liquid food matrixes such as canned beverages (soft drinks and beers) and powdered infant formula using dispersive liquid-liquid micro-extraction (DLLME) with in-situ derivatisation coupled with heart-cutting gas chromatography-mass spectrometry (GC-MS). For the optimisation of the DLLME procedure different amounts of various extractive and dispersive solvents as well as different amounts of the derivative reagent were compared for their effects on extraction efficiency and yields. The optimised procedure consisted of the injection of a mixture containing tetrachloroethylene (extractant), acetonitrile (dispersant) and acetic anhydride (derivatising reagent) directly into an aliquot of beverage samples or into an aqueous extract of powdered milk samples obtained after a pretreatment of the samples. Given the compatibility of the solvents used, and the low volumes involved, the procedure was easily associated with GC-MS end-point determination, which was accomplished by means of an accurate GC dual column (heart-cutting) technique. Careful optimisation of heart-cutting GC-MS conditions, namely pressure of front and auxiliary inlets, have resulted in a good analytical performance. The linearity of the matrix-matched calibration curves was acceptable, with coefficients of determination (r2) always higher than 0.99. Average recoveries of the BPA and BPB spiked at two concentration levels into beverages and powdered infant formula ranged from 68% to 114% and the relative standard deviation (RSD) was <15%. The limits of detection (LOD) in canned beverages were 5.0 and 2.0 ng l(-1) for BPA and BPB, respectively, whereas LOD in powdered infant formula were 60.0 and 30.0 ng l(-1), respectively. The limits of quantification (LOQ) in canned beverages were 10.0 and 7.0 ng l-1 for BPA and BPB, respectively, whereas LOQ in powdered infant formula were 200.0 and 100.0 ng l(-1), respectively. BPA was detected in 21 of 30 canned beverages (ranging from 0.03 to 4.70 μg l(-1)) and in two of seven powdered infant formula samples (0.23 and 0.40 μg l(-1)) collected in Portugal. BPB was only detected in canned beverages being positive in 15 of 30 samples analysed (ranging from 0.06 to 0.17 μg l(-1)). This is the first report about the presence of BPA and BPB in canned beverages and powdered infant formula in the Portuguese market.     

Yacon (Smallanthus Sonchifolius): A Food with Multiple Functions

Functional foods are the focus of many studies worldwide. This is justified by the effects they have on public health and thus interest in elucidation of the mechanisms involved in their actions. The present review aims to broaden the discussions of the functional properties attributed to yacon (Smallanthus sonchifolius), considered a food with multiple functions since it possesses bioactive compounds (antimicrobial, antioxidant, and probiotic substances) that exert beneficial effects on the body. Although some studies have already demonstrated several of these functions, clinical evidence is scarce, making it necessary that more studies are conducted in this area. Still, since the availability of this food in the market is relatively new, its popularity depends on publications aimed at consumer education and development of new products by the food industry.     

Changes in Phenolic Compounds During Storage of Pasteurized Strawberry

This study aimed to establish mathematical models to describe changes in phenolics of pasteurized strawberry (Fragaria?×?ananassa Duch.) during storage at 23 °C for 90 days. Freshly cut strawberries cubes were pasteurized for 5 min in a water bath at 90 °C following a heating time of 15 min. Antioxidant activity, total phenolics, total anthocyanins, and individual phenolic compounds were assessed immediately before or after pasteurization and at regular time intervals during storage. The results indicated that (1) pasteurization did not affect (P?<?0.05) the concentrations of total phenolics or total anthocyanins, but significantly reduced the concentrations of quercetin-3-rutinoside, kaempferol, and cyanidin-3-glucoside, and increased the concentrations of (+)-catechin, (?)-epicatechin, epigallocatechin gallate, quercetin-3-galactoside, and ellagic acid; (2) changes in antioxidant capacity, total anthocyanin, and individual compounds during storage were described by a pseudo-first-order model with the exception of total phenolic and specifically kaempferol and ellagic acid which followed zero-order kinetic models. Pelargonidin-3-glucoside degraded at the highest rate (k?=?0.07 day^?1), followed by ellagic acid (k?=?0.004 day^?1) and kaempferol (k?=?0.003 day^?1). The rate constants can be used to predict phytochemical changes in strawberry products during storage.