Membrane processing of grape must for control of the alcohol content in fermented beverages

The great demand of beverages, both alcohol-free and with low alcohol content, is a great challenge for the production of beverages with controlled alcohol content through the use of sustainable enological practices. The present work addresses this challenge with the processing of grape must by reverse osmosis (RO) for must reconstitution with different sugar contents prior to the alcoholic fermentation. The original must came from grapes grown in Quinta do Quinto, in Santarém, collected after destemming and mechanic crushing, and preserved in a refrigerated chamber at -1.6 °C until processing by RO. The RO processing was carried out in Escola Superior Agrária de Santarém, with a pilot plant equipped with RO spiral wound modules, M38RO, from Alfa Laval, Denmark. The total membrane permeation area is 15 m2. The work pressure was 55 bar. The original must had 23.7 oBrix, a density of 1108 g.L-1, 15.2% (v/v) of probable alcohol, and a conductivity of 2.01 mS.cm-1. The must reconstitution was carried out, by mixing the concentrated grape must with the vegetal water produced by RO (permeate) to obtain beverages with a nominal alcohol content of 5%, 7%, 10% and 13% (v/v). The fermentation average temperature was between 18.2 and 19.7 °C, and the final density rounded about 993 g.cm-3. The beverages were analysed by different parameters, including total polyphenols, total anthocyanins, colour intensity and hue, the coordinates CIELab, alcohol content, total acidity, volatile acidity, pH, free SO2 and total SO2. The attributes of the beverage, corresponding to the visual appearance, aroma and taste senses, as well as the overall judgment were evaluated by the tasters. The proposed method can produce beverages with controlled low alcohol content. The decrease of the alcohol content led to lower content of polyphenols compounds which influenced the sensory evaluation.info:eu-repo/semantics/publishedVersio

Purely elastic flow instabilities in microscale cross-slot devices

We present an experimental investigation of viscoelastic fluid flow in a cross-slot microgeometry under low Reynolds number flow conditions. By using several viscoelastic fluids, we investigate the effects of the microchannel bounding walls and of the polymer solution concentration on the flow patterns. We demonstrate that for concentrated polymer solutions, the flow undergoes a bifurcation above a critical Weissenberg number (Wi) in which the flow becomes asymmetric but remains steady. The appearance of this elastic instability depends on the channel aspect ratio, defined as the ratio between the depth and the width of the channels. At high aspect ratios, when bounding wall effects are reduced, two types of elastic instabilities were observed, one in which the flow becomes asymmetric and steady, followed by a second instability at higher Wi, in which the flow becomes time-dependent. When the aspect ratio decreases, the bounding walls have a stabilizing effect preventing the occurrence of the steady asymmetric flow and postponing the transition to unsteady flow to higher Wi. For less concentrated solutions, the first elastic instability to steady asymmetric flow is absent and only the time-dependent flow instability is observed

Staining techniques for ageing tope shark, Galeorhinus galeus (Linnaeus, 1758), from the Azores : a comparison based on precision analysis.

A vertebrae sample of tope shark, Galeorhinus galeus (Linnaeus, 1758), stratified by sizeclasses,was used to test between different staining techniques of enhancing vertebral growth ring visibility. Four techniques were tested: alizarin red, silver nitrate and cobalt nitrate staining, and the “deep-coned vertebrae” technique. The latter was discarded due to its unsuitability for tope shark vertebrae. The cobalt nitrate original protocol was modified. Upon staining, each vertebra was subject to three replicated independent readings, by a single reader. Within-reader consistency and bias of growth ring counts determination were evaluated using four different precision indices: percent of agreement (PA), average percent error (APE), coefficient of variation (V) and index of precision (D). Results indicated that the vertebrae stained with the cobalt nitrate technique showed both better optic enhancement of growth rings and higher degree of count consistency, comparatively to the alizarin red and silver stained vertebrae. Conclusively, the cobalt nitrate was the most efficient staining technique upon tope shark vertebrae, among the methods tested herein

Bacterial growth and recovery on hospital biometric devices: effect of two types of disinfectants

Objectives: The aim of the study was to evaluate the presence of bacterial contamination on biometric identification devices in a public hospital; identify the species of bacteria implicated in the contamination and assess bacterial recovery after the use of 2 types of disinfectants: alcohol 70% and isopropyl alcohol chlorhexidine. Design: Before and after trial. Setting: Public hospital, tertiary referral center. Participants: All existing biometric identification devices in the hospital (n = 20). Methods: Collection of 2 microbiological samples from the fingerprint reading surface of biometric devices immediately before and after applying the solution with alcohol 70% and in separate time periods with isopropyl alcohol chlorhexidine. Results: It have been identified 21 different bacterial species in a total of 78 samples, mostly Staphylococcus epidermidis (32 samples) and S aureus (7 samples). S epidermidis was eliminated in 61.5% of the samples after disinfecting with alcohol 70% and in 92.3% of the samples disinfected with isopropyl alcohol chlorhexidine. S aureus was eliminated in 33.3% and 100% of the samples, respectively. We found no bacterial growth in 10% of the devices after disinfection with 70% alcohol and in 78.9% of devices after disinfection with isopropyl alcohol chlorhexidine. We also found that there was a decrease in the frequency of species isolated after using both disinfection solutions, although isopropyl alcohol chlorhexidine appeared to be more effective. Conclusions: The biometric identification devices used in this hospital seem to be safe regardless of the products used for its cleaning. The majority of the bacteria found are commensal skin microorganisms. We did not find pathogenic bacteria for immunocompetent individuals, in particular methicillin-resistant S aureus

25 and 50G optical access network deployment forecasts using bi-logistic curves

Different forecast scenarios for the 25G-PON and 50G-PON Globally for both ONT/ONU markets are presented based on modeling by a Bi-Logistic function with reference to GPON existing data.info:eu-repo/semantics/acceptedVersio

Bioconversion of cellulosic biomass wastes by Azorean hot spring bacterial consortia

ECO-BIO 2016Enzymatic hydrolysis of cellulose is a fundamental step in the carbon cycle and in the industrial bioconversion of biomass to biofuels. In nature cellulose hydrolysis is often catalysed by enzymes from complex microbial communities, nevertheless these studies are limited to a few isolates. Actually the production of biofuels from biomass became a necessity and novel pre-treatments are mandatory to be discovered. Thereby the study of cellulose hydrolysing bacterial communities is a step in achieving a sustainable future in biofuels development. We propose the stabilization of an aerobic thermophilic bacterial consortia (BC) with the ability to adapt and hydrolyse different cellulose-rich wastes. Decaying cellulosic residues were sampled inside Azorean hot springs. Samples were enriched in cellulosic selective medium at 60ºC with growth monitored quantifying DNA. Hydrolysis efficiency was monitored and enzymatic activity was detected using xylan and carboxymetylcellulose (CMC). 16S rRNA hypervariable regions V3/V4 were amplified for phylogenetic characterization of BC using 454 pyrosequencing. Selected BC was able to hydrolyse 50% of cellulose-rich plant mix material in 4 days. Besides hydrolysing low content lignin material as non-wood plants, newspaper and cardboard, the consortia was able to hydrolyse high lignin content material, with lower efficiency. Celulase and xylanase were present in BC and reducing sugars were shown to be higher, compared with control. The phylogenetic results showed a large diversity in the BC with Thermobacillus representing 44% of the consortia, followed by Symbiobacterium 25%, Brevibacillus 16%, Geobacillus 12% and Hipomicrobium 3%. Three Geobacillus species were identified; G. stearothermophilus, G.thermodenitrificans and G.debilis. Further work will comply the isolation of enzyme producing bacteria isolates from the consortia for the construction of new consortia taking in consideration the efficiency of cellulose rich wastes. These results suggest that bacterial communities can be an alternative pre-treatment method of green wastes to obtain molecules to biofuels production.info:eu-repo/semantics/publishedVersio

Degradable particulate composite reinforced with nanofibres for biomedical applications

Nanofibre-based structures and their composites are increasingly being studied for many biomedical applications, including tissue engineering scaffolds. These materials enable architectures resembling the extracellular matrix to be obtained. The search for optimized supports and carriers of cells is still a major challenge for the tissue engineering field. The main purpose of this work is to develop a novel composite structure that combines microparticles and nanofibres in reinforced polymeric microfibres. This innovative combination of materials is obtained by melting extrusion of a particulate composite reinforced with chitosan nanofibre meshes (0.05 wt.%) produced by the electrospinning technique. The reinforced microfibres were analysed by scanning electron microscopy and showed a considerable alignment of the chitosan nanofibres along the longitudinal main axis of the microfibre composite structure. The tensile mechanical properties revealed that the introduction of the nanofibre reinforcement in the particulate microfibre composite increased the tensile modulus by up to 70%. The various structures were subjected to swelling and degradation tests immersed in an isotonic saline solution at 37 C. The presence of chitosan nanofibres in the particulate microfibres enhances the water uptake by up to 24%. The combination of good mechanical properties and enhanced degradability of the developed structures is believed to have great potential for various biomedical applications, including three-dimensional fibre mesh scaffolds to be applied in the field of bone tissue engineering.This work was partially supported by the EU Integrated Project GENOSTEM (No. LSH503161) and by project Micro-Nano (POCI/CTM/48040/2002), financed by the Portuguese Foundation for Science and Technology (FCT). A.M. would like to thank FCT for his PhD grant (SFRH/BD/24382/2005)

Rheological behavior of human blood in uniaxial extensional flow

We present an investigation of the rheological behavior of whole human blood under uniaxial extensional flow. For that purpose, capillary breakup experiments were carried out by combining the slow retraction method, high-speed imaging techniques and an immiscible oil bath. The use of the oil bath was aimed at reducing liquid loss by evaporation and to reduce light refraction effects, thus allowing the visualization of the blood cells during the filament thinning. Extensional relaxation times were measured for whole blood samples collected from a total of thirteen healthy adult volunteers from both genders, with hematocrit levels between 38.7% and 46.3%. For this range of red blood cell concentrations, the variation of the extensional relaxation time is small, with the average extensional relaxation times measured in air and in oil being 114±30 μs and 259±47 μs, respectively. An increase of the red blood cells concentration leads to an increase of the bulk viscosity of the sample, which delays the thinning of the filament and consequently the time to breakup. In addition, blood aging was found to reduce the relaxation time while the absence of anticoagulant increases it significantly

Size also matters in biodegradable composite microfiber reinforced by chitosan nanofibers

Pioneer works on nanocomposites were focused in carbon nanofibers or nanotubes dispersed in epoxy matrix, a viscous liquid facilitating the compounding stage. The interest in developing new composites aimed for biomedical applications led us to design new nanocomposites based in biodegradable polymers with demonstrated biological performance. We report herein the development of micro-nano composites by extruding poly(butylene succinate) (PBS) microfibers with two different diameters, 200 and 500 m, reinforced with electrospun chitosan nanofibers. Analysis of the microfibers showed high levels of alignment of the reinforcing phase and excellent distribution of the nanofibers in the composite. Its geometry facilitates the development of orthotropy, maximizing the reinforcement in the axial fiber main axis. The biodegradable microfiber composites show an outstanding improvement of mechanical properties and of the kinetics of biodegradation, with very small fractions (0.05 and 0.1 wt.%) of electrospun chitosan nanofibers reinforcement. The high surface area-to-volume ratio of electrospun nanofibers combined with the increased water uptake capability of chitosan justify the accelerated kinetics of biodegradation of the composite as compared with the unfilled synthetic polymer.FCT -Fundação para a Ciência e a Tecnologi

Effects of age-related cognitive deficits on EEG phase coherence

Body and brain undergo several changes with aging. One of these changes is the loss of neuroplasticity, which leads to the decrease of cognitive abilities. Hence the necessity of stopping or reversing these changes is of utmost importance to contemporary society. In the present work, electroencephalogram (EEG) markers of cognitive decline are sought whilst the subjects perform the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young and elder participants. The results suggest that coherence on theta and alpha EEG rhythms decrease with aging and increase with performance. Additionally, theta phase coherence seems more sensitive to performance, while alpha synchronization appears as a potential ageing markerFCT-Foundation for Science and Technology and Compete Program with the project reference FCOMP-01-0124-FED ER-021145 (PTDC/SAU-ENB/118383/2010