Multifunction MMIC For Miniaturized Solid State Switch Matrix

This paper describes a new multifunction MMIC expressly designed for a reconfiguration matrix equipment.This MMIC has been developed using a standard PHEMT process and includes two switches,a totally switchable-off amplifier and a temperature compensation circuit.The complete circuit has also been designed to interface a standard CMOS control level. Performed simulations and obtained results demonstrate the effectiveness of this approach in reaching compactness and reliability of satellite equipment

Ku & C Band solid state switch matrix for satellite payloads using LTCC multilayer substrate

This paper describes the design and development of Ku and C band solid state switch matrix for multimedia satellite payloads. The design, through the use of advanced packaging techniques, allows significant savings on mass and volume with respect to traditional electromechanical switches while guaranteeing a comparable reliability

Using Augmented and Virtual Reality for teaching scientific disciplines

This paper aims at synthesizing the literature on the use of AR and VR for teaching scientific disciplines to identify strengths and weaknesses for student’s learning. Articles published in peer reviewed journals has been searched on Google Scholar from 2018. The results highlighted a great variety of studies’ methodology, field of applications, technology, target groups and outcomes. The growing interest in this topic is due to the emerging benefits for learning achievements, attitudes and motivations. Further studies are necessary to understand the type of technologies to be used in different contexts and to focus on learners’ characteristics, and its impact on learning outcomes. It is necessary to improve students’ and teachers’ digital competence, supporting them in designing educational intervention for the acquisition of scientific skills

Antioxidative defence mechanisms in two grapevine (Vitis vinifera L.) cultivars grown under boron excess in the irrigation water

The aim of this study was to investigate the impact of B excess on the antioxidative defence system in two grapevine cultivars differently sensitive to B, in order to evaluate in which way the different sensitivity was correlated to the activation of defence mechanisms. Two-year-old Vitis vinifera L. plants (‘Merlot’ and ‘Sangiovese’), grafted on the same rootstock, were subjected to B treatment as potted vines, and biochemical determinations were employed to evaluate the antioxidative response. Compared to ‘Sangiovese’, ‘Merlot’ showed a much higher B accumulation and both leaf and peroxidative damages. In B-treated ‘Sangiovese’ the activity of superoxide dismutase did not change compared to control leaves, whereas in ‘Merlot’ a dramatic decrease in the enzyme activity was observed. B increased reduced ascorbate pools in both cultivars, but ascorbate peroxidase activity was enhanced only in ‘Merlot’. In this latter cv. an enhancement of total phenols was also observed. ‘Merlot’ showed a lower ability to contrast B accumulation in leaves than ‘Sangiovese’ evidencing a higher oxidative stress. Even if defence mechanisms were generally activated in ‘Merlot’, they did not counteract efficiently metabolic damages likely due to the dramatic decrease in superoxide dismutase, the first enzyme involved in the detoxification of oxygen radicals

Mobile learning for the integration of groups that risk being marginalized

Social inclusion and cohesion are two of the objectives that the European Union has very often proclaimed in its documents, in the past ten years. At the same time, community policies have emphasized the role that ICTs can play to encourage and support participation and integration opportunities of disadvantaged citizens. Within this context, the ENSEMBLE project, presented here, aims at developing a strategy of use of ICTs to promote socio-cultural integration of immigrant citizens by using technologies such as MP3 players and mobile phones, and by experimenting instructional methods and communication models suitable for the adopted instruments. The present paper focuses particularly on the educational communication design of MMS messages

Uncovering the host galaxy of the γ\gamma-ray-emitting narrow-line Seyfert 1 galaxy FBQS J1644+2619

The discovery of $\gamma$-ray emission from radio-loud narrow-line Seyfert 1 (NLSy1) galaxies has questioned the need for large black hole masses (> 10$^8$ M$_{\odot}$) to launch relativistic jets. We present near-infrared data of the $\gamma$-ray-emitting NLSy1 FBQS J1644+2619 that were collected using the camera CIRCE (Canarias InfraRed Camera Experiment) at the 10.4-m Gran Telescopio Canarias to investigate the structural properties of its host galaxy and to infer the black hole mass. The 2D surface brightness profile is modelled by the combination of a nuclear and a bulge component with a S\'ersic profile with index $n$ = 3.7, indicative of an elliptical galaxy. The structural parameters of the host are consistent with the correlations of effective radius and surface brightness against absolute magnitude measured for elliptical galaxies. From the bulge luminosity, we estimated a black hole mass of (2.1$\pm$0.2) $\times$10$^8$ M$_{\odot}$, consistent with the values characterizing radio-loud active galactic nuclei.Comment: 5 pages, 3 figures, 1 table. Monthly Notices of the Royal Astronomical Society Letter, Vol. 469, L11-L1

Hemp Biomass Pretreatment and Fermentation with non- Saccharomyces Yeasts: Xylose Valorization to Xylitol

Hemp hurds are the main byproduct from hemp fibers supply chain and they could represent valuable feedstock of lignocellulosic biomass for biorefineries. The industrial hemp variety "Carmagnola", is characterized by low amounts of ash and high amount of carbohydrates. Alpha-cellulose (44% w/w), hemicellulose (25%), and lignin (23%) were fractionated using an organosolv pretreatment. The enzymatic hydrolysis of the cellulose fraction yielded up to 60% of glucose, that can easily find application as substrate for industrial fermentations. On the other hand, the black liquor originating from hemicellulose contains mainly xylose and minor amounts of other sugars. In the perspective of finding an application of black liquor, 50 yeasts belonging to 24 ascomycetous species were screened both in aerobiosis and anaerobiosis for the production of ethanol and the sugar alcohols xylitol and arabitol from xylose. Pichia fermentans WC 1507, Wickerhamomyces anomalus WC 1501, and Kluyveromyces bacillosporus WC 1404 were found to consume xylose, yielding xylitol in aerobic conditions. In particular, aerobic flask cultures of P. fermentans WC 1507 containing 120 g/L xylose showed the highest xylitol production values, yielding 63.5 g/L xylitol with a YP/S of 71.5%. Black liquor, exploited as a carbon source, has been successfully utilized by the three selected yeast strains at a concentration of 20 g/L in the culture medium, resulting in comparable or higher yields of biomass and xylitol compared to the medium containing pure xylose. A higher concentration of black liquor in the culture medium (to reach 120 g/l of xylose) has determined an inhibition of the growth of yeasts indicating the need for treatments for the removal of inhibitors. These preliminary results can be considered promising for the microbial valorization of lignocellulosic hemp feedstock toward the production of xylitol

Photosynthetic responses to salinity in two obligate halophytes: Sesuvium portulacastrum and Tecticornia indica

Abstract Seedlings of the obligate halophytes Sesuvium portulacastrum L. and Tecticornia indica (Willd.) subsp. indica were grown with 0, 200, or 400 mM NaCl for 13 weeks to investigate whether salt tolerance was related to maintenance of adequate photosynthetic activity and pigment equipment. Both species showed growth optimum at 200 mM NaCl and better tissue hydration under salinity but different photosynthetic response to salinity. CO2 assimilation rate and stomatal conductance of S. portulacastrum were highest at 200 mM NaCl, while in T. indica they decreased with salinity. Pigment content increased under salinity in both species. The de-epoxidation state in S. portulacastrum suggests the need for energy dissipation at 400 mM NaCl, while its salt-induced decline in T. indica, despite the reduced photochemistry, suggests the involvement of adaptive mechanisms other than the xanthophyll cycle