Production of Ag−ZnO powders by hot mechanochemical processing

Ag–CdO composites are still one of the most commonly used electrical contact materials in low-voltage applications owing to their excellent electrical and mechanical properties. Nevertheless, considering the restriction on using Cd due to its toxicity, it is necessary to find alternative materials that can replace these composites. In this study, the synthesis of Ag?ZnO alloys from Ag?Zn solid solutions was investigated by hot mechanochemical processing. The hot mechanochemical processing was conducted in a modified attritor mill at 138 °C under flowing O₂ at 1200 cm³/min for 3.0 h. The microstructure and phase evolution were investigated using X-ray diffractometry, field emission gun scanning electron microscopy and transmission electron microscopy. The results suggest that it is possible to complete the oxidation of Ag?Zn solid solution by hot mechanochemical processing at a low temperature and short time. This novel synthesis route can produce Ag?ZnO composites with a homogeneous distribution of nanoscale ZnO precipitates, which is impossible to achieve using the conventional material processing methods. Considering the fact that the fundamental approach to improving electric contact material performance resides in obtaining uniform dispersion of the second-phase in the Ag matrix, this new processing route could open the possibility for Ag?ZnO composites to replace non-environmentally friendly Ag?CdO.     

The influence of breed on the organoleptic characteristics of Zamorano sheep’s raw milk cheese and its assessment by instrumental analysis

The aim of this study was to investigate the effects of three different somatic cell count (SCC) values on the sensory characteristics of sheep’s milk cheeses from the Castellana and Churra breeds (allowed for Protected Designation of Origin Zamorano cheese manufacture) and the Assaf breed (foreign), determined by typical consumers and instrumentally. The results show that the sensory characteristics of hardness, intensity of taste, and pungency reflect a significant influence of the SCCs of the original milk whereas breed significantly affects colour intensity and hardness (Warner‐Bratzler maximum shear force; WBSF). The instrumental parameters most closely related to the assessments of the typical consumers were WBSF and the value of a*, for hardness and colour respectively.     

Decrease in laser ablation threshold for epithelial tissue microsurgery in a living Drosophila embryo during dorsal closure

In this work, we use a two‐photon fluorescence microscope for combined imaging and laser tissue ablation of a living Drosophila Melanogaster embryo. By using tightly focused near‐infrared femtosecond pulses at MHz repetition rate and of sub‐nanojoule energy we are able to produce microsurgery on the epithelial tissue within a Drosophila embryo at the final stages of its embryonic development. Ablation was performed on labelled and unlabelled embryos during and after dorsal closure. We observed that ablation of GFP‐labelled tissue required lower energy deposition than unlabelled tissue ensuring that the tissue ablation is mediated by multiphoton absorption of Green Fluorescent Protein (GFP). In addition, the energy deposition to produce ablation is further decreased during dorsal closure. These results show the presence of additional tensile forces on the tissue during dorsal closure. Furthermore, an increased activity of actin near the laser wounds was observed as the tissue heals.     

Identification of and relationships among a number of teinturier grapevines that expanded across Europe in the early 20th century

Background and Aims: The arrival in Europe of powdery mildew (1845), phylloxera (1863) and mildew (1878) led to great interest in grapevine varieties less sensitive to these diseases, but still producing good quality wine. Standing out was a small group of teinturier vines that were once much appreciated for the colour their grapes brought to wines because of their pigmented skins and pulp. The aim of the present work was to determine the true identity of nine teinturier grapevine varieties that were collected from different vine‐growing areas of northern and north‐western Spain under local names. Methods and Results: This study combined the ampelographic characterisation of the leaves and the use of molecular markers (simple sequence repeats) to allow some of these varieties to be identified, the existence of a number of synonyms to be established and the relationships among some of these grapevines to be determined. Conclusions: Most of the teinturier varieties studied are related to the internationally known cultivars Morrastrel Bouschet, Alicante Bouschet, Petit Bouschet and Jacquez. The origin of the teinturier variety collected with the local name Folla Redonda is still unknown. Significance of the Study: The information provided by this research helps define the origin of commercially important teinturier varieties and may be helpful in their identification and selection for cultivation in certain vine‐growing areas.     

DIELECTRIC AND PHASE TRANSITION PROPERTIES OF GD DOPED PbZr0.53Ti0.47O3

ABSTRACT

PbZr_0.53Ti_0.47O₃ (PZT53/47) doped with 0.6% wt. Gd₂O₃ was synthesized following the solid state reaction technique. X-ray diffraction indicated a rhombohedral structure. The grain size distribution was centered at 3 μ m with grains as big as 6 μ m. Dielectric studies in the 100 Hz to 1 MHz and the 25 to 450°C frequency and temperature ranges, yielded values above 40,000 for the relative permittivity. The transition temperature decreased from 386°C for the undoped ceramic to 352°C. Hysteresis loops were taken at 23°C and applied electric fields up to 17 kV/cm. The radial electromechanical coupling-factor was 0.12.     

In-port-plug transmission line design of the ITER plasma position reflectometer

This work describes the microwave design of the transmission line housed in the in-port-plug region of the ITER plasma position reflectometer(PPR). The design of the components of the inport-plug reflectometers(located in equatorial port-plug 10(EPP10) and in upper-port-plug 01(UPP01)) is presented. Using a 3 D ray tracing code, the spatial position and optimum orientation angles of each set of emission and detection antennas were determined. A feasible path was then created from the obtained antenna positions and orientations to the primary vacuum window.Oversized tall waveguides were chosen to reduce ohmic losses. Due to space constraints in the ITER crowded environment, bends in oversized waveguides were unavoidable, and thus mode conversion was produced. To keep mode conversion losses at bay, hyperbolic secant curvature bends had to be used whenever possible. However, E-plane bends in tall waveguides proved to be especially critical, making it necessary to employ other approaches when higher bending angles were needed. Mode conversion results were obtained by evaluating the mode coupling equations. Ohmic losses have also been computed and their results compared with commercial simulators, obtaining a perfect agreement.