Optimization of chalcogenide glass in the As–Se–S system for automotive applications

Infrared transmitting glasses in the As–Se–S system have been optimized by taking in account specifications for automotive application. The As₂Se₃ glass has been chosen as the starting composition and sulfur is introduced in order to improve some optical and mechanical properties. As expected, the Sulfur introduction decreases the refractive index as well as its change as function of temperature. The relationship between the refractive index and the glass composition has been established. The thermal coefficient of refractive index for sulfur containing glasses can be lower than 4 × 10⁻⁵ K⁻¹, which is considerably lower than that of germanium, the most used infrared transmitting materials. Influence of sulfur on other properties has also been studied.     

Photovoltaic system simulation using a standard electronic circuit simulator

An approach to photovoltaic (PV) system simulation is presented based on the use of SPICE instead of using a specifically developed software package. SPICE models for PV cells, PV modules, lead-acid batteries and the rest of the main components of a PV system have been developed. A simulation example of a stand-alone PV system including measured irradiance data as an input is used to show some of the possibilities inherent in such an approach. Greater flexibility, quick access to all voltages and currents within the system and a simpler way of interfacing with standard electronic components are the main conclusions to be drawn from this work.     

Flowering as the Most Highly Sensitive Period of Grapevine (Vitis vinifera L. cv Mourvèdre) to the Botryosphaeria Dieback Agents Neofusicoccum parvum and Diplodia seriata Infection

Botryosphaeria dieback is a fungal grapevine trunk disease that currently represents a threat for viticulture worldwide because of the important economical losses due to reduced yield of affected plants and their premature death. Neofusicoccum parvum and Diplodia seriata are among the causal agents. Vine green stems were artificially infected with N. parvum or D. seriata at the onset of three different phenological stages (G stage (separated clusters), flowering and veraison). Highest mean lesion lengths were recorded at flowering. Major proteome changes associated to artificial infections during the three different phenological stages were also reported using two dimensional gel electrophoresis (2D)-based analysis. Twenty (G stage), 15 (flowering) and 13 (veraison) differentially expressed protein spots were subjected to nanoLC-MS/MS and a total of 247, 54 and 25 proteins were respectively identified. At flowering, a weaker response to the infection was likely activated as compared to the other stages, and some defense-related proteins were even down regulated (e.g., superoxide dismutase, major latex-like protein, and pathogenesis related protein 10). Globally, the flowering period seemed to represent the period of highest sensitivity of grapevine to Botryosphaeria dieback agent infection, possibly being related to the high metabolic activity in the inflorescences.     

Green extraction of natural products: concept and principles

The design of green and sustainable extraction methods of natural products is currently a hot research topic in the multidisciplinary area of applied chemistry, biology and technology. Herein we aimed to introduce the six principles of green-extraction, describing a multifaceted strategy to apply this concept at research and industrial level. The mainstay of this working protocol are new and innovative technologies, process intensification, agro-solvents and energy saving. The concept, principles and examples of green extraction here discussed, offer an updated glimpse of the huge technological effort that is being made and the diverse applications that are being developed.     

Ultrasound-assisted extraction of polyphenols (flavanone glycosides) from orange (Citrus sinensis L.) peel

The present study reports on the extraction of polyphenols especially flavanones from orange (Citrus sinensis L.) peel by using ethanol as a food grade solvent. After a preliminary study showing that the best yield of extraction was reached for a particle size of 2 cm², a response surface methodology (RSM) was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE) followed by a central composite design (CCD) approach. The statistical analysis revealed that the optimised conditions were a temperature of 40 °C, a sonication power of 150 W and a 4:1 (v/v) ethanol:water ratio. The high total phenolic content (275.8 mg of gallic acid equivalent/100 g FW), flavanone concentrations (70.3 mg of naringin and 205.2 mg of hesperidin/100 g FW) and extraction yield (10.9 %) obtained from optimised UAE proved its efficiency when compared with the conventional method. Furthermore, the antioxidant activity determined by the DPPH and ORAC tests confirmed the suitability of UAE for the preparation of antioxidant-rich plant extracts.     

Simple quantum information algorithms in cavity QED

Abstract

Cavity quantum electrodynamics has already proven to be a system capable of demonstrating basic tools in quantum information theory. By combining these tools, we show how simple quantum information protocols could be implemented. We will focus on the examples of the Grover search algorithm and quantum cloning.