The Douro wine region: a cluster approach

The globalization of the wine industry needs to be perceived as a challenge and an opportunity to innovate by traditional European producers’ countries, like Portugal, characterized by a terroir model, that is, an economic structure supported by a large number of grape growers, small and medium wine firms and high public regulation, to compete in international markets. Using a cluster approach, this article presents the case of the most important Portuguese wine region, the Demarcated Douro Region (DDR), which is a strong reference of terroir and known for producing Port wine. To increase its competitiveness in the world wine market, the DDR needs to evolve from an organized to an innovative cluster.     

Application of Mid- and Near-Infrared Spectroscopy for the Control and Chemical Evaluation of Brine Solutions and Traditional Sea Salts

Mid- and near-infrared spectroscopy methodologies were explored for the analysis of brine solutions and traditional sea salt samples. Brine solutions from different salt pans, corresponding to different stages of sodium chloride crystallisation, were collected. A total of 61 dried and non-dried traditional sea salts were also analysed. Partial least squares regression with leave-one-out cross-validation strategy was applied for the calibration of inorganic constituents Ca²⁺, Mg²⁺ and K⁺, alkalinity as HCO ₃ ^? , SO ₄ ^2? , NO ₂ ^? and NO ₃ ^? and phosphate in brine solutions. Promising results were obtained with the near-infrared (NIR) methodology for brine solutions with coefficients of determination R ²?>?0.90 for Mg⁺², K⁺, HCO ₃ ^? and SO ₄ ^2? . Using mid-infrared, the calibration for H₂PO ₄ ^? was R ²?=?0.85. In relation to the sea salt samples, the strategy adopted was the re-sampling based cross-validation using different spectral pre-processing treatments. In this case, the calibrations using the two IR methodologies fell bellow acceptable levels for the techniques; however, by comparing the R ² coefficient, the results were slightly better when using the NIR spectra of dried sea samples. In general, these results open a new possibility for the IR applications and also bring an opportunity for continuing with the NIR characterization for dried sea salt samples.     

Evaluation of three different microbial inhibition tests for the detection of sulphamethazine residues in the edible tissues of rabbit

The aim of the present study was to evaluate three microbial inhibition tests (MIT) based on inhibition of growth of the test organisms: (a) four plate test (FPT) containing Bacillus subtilis BGA, (b) screening test for antibiotic residues (STAR) containing Bacillus stearothermophilus var. calidolactis_ATCC 10149 and (c) the Premi®Test containing Bacillus stearothermophilus var. calidolactis. The tests were used to determine sulphamethazine (SMZ) residues in edible tissues of rabbit after oral administration up to day 15 of the withdrawal period (WP). A solvent extraction procedure was used to enhance the capability of the tests to detect SMZ residues at or below the maximum residue limit (MRL). Para-aminobenzoic acid (PABA) was employed to previously identify SMZ residues in the first stage of the residue screening. The presence of SMZ residues in the samples was confirmed and quantified by a validated HPLC method. The Premi®Test detected SMZ residues in the muscle and heart tissue up to day 9 of the WP, and in the liver, lungs and kidneys up to day 10 of the WP. The STAR detected SMZ residues in the edible organs of rabbits up to day 8 of the WP. The kidneys were positive up to day 5 of the WP, the liver until day 4 of the WP and the lungs until day 3 of the WP. No SMZ residues were detected in the muscle and heart. By using the solvent extraction procedure, SMZ residues were detected in the muscle extract up to day 10 of the WP and the muscle was positive until day 6 of the WP. No detection sensitivity was observed using the FPT. After solvent extraction, SMZ residues were detected in the muscle extract until day 8 of the WP and the muscle was positive until day 3 of the WP. No positive results were detected after the addition of PABA into/onto the agar medium. PABA at a concentration of 10 µg ml^?1 completely reversed the inhibitory activity of SMZ and enabled reliable identification of SMZ in the examined samples. Using HPLC, SMZ was detected in the muscle samples until day 10 of WP (0.02 mg kg^?1) and in the liver until day 12 of the WP (0.09 mg kg^?1). The results obtained by the HPLC method and the limit of detection (LOD) of screening tests for SMZ (FPT 0.4 µg ml^?1, STAR 0.2 µg ml^?1, Premi® Test 0.05 µg ml^?1) allowed us to state that the most suitable screening tests for the detection of SMZ residues in the edible tissues of rabbits at level corresponding to the MRL of 0.1 mg kg^?1, established for sulphonamides, are the Premi®Test and STAR in conjunction with the solvent-extraction procedure.     

Strongly Photosensitive and Fluorescent F8T2 Electrospun Fibers

Electrospun fibers of poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐bithiophene] (F8T2) with exceptional electro‐optical performance are obtained. The I/T characteristics measured in fibers with 7–15 µm diameter and 1 mm length show a semiconductor behavior; their thermal activation energy is 0.5 eV and the dark conductivity at RT is 5 × 10^?9 (Ω cm)^?1. Besides exhibiting a photosensitivity of about 60 under white light illumination with a light power intensity of 25 mW · cm^?2, the fibers also attain RT photoluminescence in the cyan, yellow, and red wavelength range under ultraviolet, blue, and green light excitation, respectively. Optical microscope images of F8T2 reveal homogeneous electrospun fibers, which are in good agreement with the uniformly radial fluorescence observed.

     

Side information creation for efficient Wyner–Ziv video coding: Classifying and reviewing

Video coding technologies have played a major role in the explosion of large market digital video applications and services. In this context, the very popular MPEG-x and H-26x video coding standards adopted a predictive coding paradigm, where complex encoders exploit the data redundancy and irrelevancy to ‘control’ much simpler decoders. This codec paradigm fits well applications and services such as digital television and video storage where the decoder complexity is critical, but does not match well the requirements of emerging applications such as visual sensor networks where the encoder complexity is more critical. The Slepian–Wolf and Wyner–Ziv theorems brought the possibility to develop the so-called Wyner–Ziv video codecs, following a different coding paradigm where it is the task of the decoder, and not anymore of the encoder, to (fully or partly) exploit the video redundancy. Theoretically, Wyner–Ziv video coding does not incur in any compression performance penalty regarding the more traditional predictive coding paradigm (at least for certain conditions). In the context of Wyner–Ziv video codecs, the so-called side information, which is a decoder estimate of the original frame to code, plays a critical role in the overall compression performance. For this reason, much research effort has been invested in the past decade to develop increasingly more efficient side information creation methods. This paper has the main objective to review and evaluate the available side information methods after proposing a classification taxonomy to guide this review, allowing to achieve more solid conclusions and better identify the next relevant research challenges. After classifying the side information creation methods into four classes, notably guess, try, hint and learn, the review of the most important techniques in each class and the evaluation of some of them leads to the important conclusion that the side information creation methods provide better rate-distortion (RD) performance depending on the amount of temporal correlation in each video sequence. It became also clear that the best available Wyner–Ziv video coding solutions are almost systematically based on the learn approach. The best solutions are already able to systematically outperform the H.264/AVC Intra, and also the H.264/AVC zero-motion standard solutions for specific types of content.     

A reference-free 7-bit 500 MS/s pipeline ADC using current-mode reference shifting and quantizers with built-in thresholds

The pursuit for energy and area efficient circuits has become greater than ever. Low power and small area integrated circuits are in high demand today. Reference voltage circuitry for analog-to-digital conversion comprises 20–30 % of the overall power and area of the ADC. To this end, a fully differential 1.5-bit multiplying digital-to-analog converter (MDAC) precluding reference voltages, that can be employed in MDAC-based ADCs, is presented. Reference shifting is performed in current-mode and the gain of two is obtained by associating charged capacitors in series in the opamp’s feedback loop, achieving a unity feedback factor. Theoretical analyses of various nonideal effects of the reference shifting and gain of two are presented and confirmed with electrical level simulations. Furthermore, to avoid reference voltages in the local quantizers, an architecture with built-in thresholds is used. A proof of concept 1.5-bit/stage 7-bit 500 MS/s pipeline ADC is designed using the proposed MDAC in a standard digital 0.13 μm CMOS technology. The ADC achieves a peak SNDR and SFDR of 36.1 and 48.7 dB, respectively, while dissipating 12.7 mW from a single 1.2 V supply voltage, and it does not require external reference circuitry.     

Synthesis of 3D Silver-Graphene-Titanium Dioxide Composite via Aerosol Spray Pyrolysis for Sensitive Glucose Biosensor

A sensitive glucose biosensor was developed based on the adsorption of glucose oxidase by a three-dimensional silver-graphene-titanium dioxide (3D Ag-GR-TiO₂) composite electrode. Aerosol spray pyrolysis was employed to synthesize the 3D Ag-GR-TiO₂ composite using a colloidal mixture of a silver acetate precursor (C₂H₃AgO₂), graphene oxide, and TiO₂ nanoparticles. The effects of the operating temperature, gas flowrate, and TiO₂ concentration on the particle properties were investigated. The particle morphology of all 3D Ag-GR-TiO₂ composites was spherical in shape. The average sizes of composites could be controlled from 0.45 to 0.64 μm with the variation of process variables. Ag nanoparticles less than 10 nm in diameter were deposited on the surfaces of the TiO₂ nanoparticles and GR after a reduction process. The characteristics of the glucose biosensor fabricated with the as-prepared 3D Ag-GR-TiO₂ composite were assessed through cyclic voltammetry measurements. The biosensor exhibited a high current flow as well as clear redox peaks, resulting in a superior ability of the catalyst in terms of the electrochemical reactions. The highest sensitivity of glucose biosensor was obtained by 3D Ag-GR-TiO₂ composite, which was 12.2 μA/mM·cm², among 3D Ag-GR-TiO₂, 3D Ag-GR, and 3D GR-TiO₂ composites.

Copyright 2015 American Association for Aerosol Research     

The influence of polycaprolactone content on the surface properties of polyurethane networks

The aim of this work was to examine the influence of polycaprolactone (PCL) as a soft segment (SS) on the surface properties of polyurethane networks (PUNs). Five PUNs with different SS content (from 10 to 50 wt%) were prepared using Boltorn® aliphatic hyperbranched polyester of the second pseudo generation and isophorone diisocyanate as components of hard segments. The structure, hydrophobicity, wettability, and swelling behavior of these PUNs were investigated. Primarily, the obtained results showed that properties of prepared PUNs strongly depend on the content of SS that is, PCL. It has been established that the increase of SS content reduced the degree of hydrogen bonding in PUNs. Also, the increase of the SS content in PUNs induced appearance of more pronounced microphase separated morphology, better hydrophobicity and non-wetting with diiodomethane. Simultaneously, the increase of the SS content led to the decrease of contact angles with formamide, and surface free energy of the prepared PUNs. These PUNs show good surface properties that are required for their potential application such as coatings.     

Crystallization of Zirconium-Rich PLZT Thin Films Below 500°C

The general problem of processing zirconium-rich lead-lanthanum-zirconate-titanate (PLZT) thin films at the commonly used temperatures between 600 and 650 C is lead-oxide loss, leading to the formation of a non-ferroelectric, surface pyrochlore-type phase. To avoid lead-oxide losses due to sublimation and/or the interaction of the film with the substrate, it is desirable that the annealing temperatures are as low as possible. Our goal was to study and prepare perovskite PLZT 9.5/65/35 (Pb 0.858 La 0.095 Zr 0.65 Ti 0.35 O 3 ) thin films below 500 C. At 400 C the growth of the perovskite phase follows the parabolic law typical of diffusion controlled processes. During prolonged annealing growth continues until the limiting stoichiometry of the perovskite phase with regard to the PbO is reached. We conclude that, even at this low temperature the amount of PbO in the film is the critical factor in the crystallization of the perovskite phase.     

Junctionless MOSFETs with laterally graded-doping channel for analog/RF applications

In this paper, we propose a laterally graded-channel pseudo-junctionless (GPJL) MOSFET for analog/RF applications. We examine the dynamical performance of GPJL MOSFET and compare it with the common junctionless (JL) MOSFET architecture using a 2-D full-band electron Monte Carlo simulator (MC) with quantum correction. Our results indicate that the GPJL MOSFET outperforms the conventional JL MOSFET, yielding higher values of drain current (I _ds), transconductance (g _m), and cutoff frequency (f _t). Further, the emerging electric field and velocity distributions, as a consequence of the channel engineering introduced by the GPJL MOSFET, result in lower output conductance (g _ds) and higher early voltage (V _ea). The preeminence of the GPJL transistor over the JL transistor is further illustrated by showing improvements on the intrinsic voltage gain (A _vo) in the subthreshold regime, to as high as 61 %. These results indicate that our proposed GPJL MOSFET yields improvement in the analog/RF performance metrics as compared to JL MOSFETs.