383 research outputs found
Innovative antibacterial biocomposite films based on biomacromolecules and nanostructured zinc oxide
L'abstract è presente nell'allegato / the abstract is in the attachmen
Engineering interband tunneling in nanowires with diamond cubic or zincblende crystalline structure based on atomistic modeling
We present an investigation in the device parameter space of band-to-band
tunneling in nanowires with a diamond cubic or zincblende crystalline
structure. Results are obtained from quantum transport simulations based on
Non-Equilibrium Green's functions with a tight-binding atomistic Hamiltonian.
Interband tunneling is extremely sensitive to the longitudinal electric field,
to the nanowire cross section, through the gap, and to the material. We have
derived an approximate analytical expression for the transmission probability
based on WKB theory and on a proper choice of the effective interband tunneling
mass, which shows good agreement with results from atomistic quantum
simulation.Comment: 4 pages, 3 figures. Final version, published in IEEE Trans.
Nanotechnol. It differs from the previous arXiv version for the title and for
some changes in the text and in the reference
The Whole is More than the Sum of its Parts: Updates from the TURTLE Group Towards The Global Development of a Lunar Exploration Technology Adaptive Roadmap
Experimental validation of a SAR-Based RFID localization technique exploiting an automated handling system
The synthetic aperture radar (SAR) approach has attracted a considerable interest in the context of phase-based techniques for the localization of UHF-RFID passive tags. In this letter, the results of an extensive experimental activity are presented, when the reader antenna is moved in front of a set of static passive UHF-RFID tags by means of a planar handling system. Measured performance is evaluated with respect to several system parameters: tag number and typology, tag reciprocal distance and orientation, trajectory and speed of the moving reader antenna. It is shown that the SAR processing can guarantee an accurate two-dimensional localization of multiple tags, with a localization error comparable to the size of typical commercial tags, by using a single reader antenna and without the need for any reference tag
Antimicrobial Nano-Zinc Oxide Biocomposites for Wound Healing Applications: A Review
Chronic wounds are a major concern for global health, affecting millions of individuals worldwide. As their occurrence is correlated with age and age-related comorbidities, their incidence in the population is set to increase in the forthcoming years. This burden is further worsened by the rise of antimicrobial resistance (AMR), which causes wound infections that are increasingly hard to treat with current antibiotics. Antimicrobial bionanocomposites are an emerging class of materials that combine the biocompatibility and tissue-mimicking properties of biomacromolecules with the antimicrobial activity of metal or metal oxide nanoparticles. Among these nanostructured agents, zinc oxide (ZnO) is one of the most promising for its microbicidal effects and its anti-inflammatory properties, and as a source of essential zinc ions. This review analyses the most recent developments in the field of nano-ZnO–bionanocomposite (nZnO-BNC) materials—mainly in the form of films, but also hydrogel or electrospun bandages—from the different preparation techniques to their properties and antibacterial and wound-healing performances. The effect of nanostructured ZnO on the mechanical, water and gas barrier, swelling, optical, thermal, water affinity, and drug-release properties are examined and linked to the preparation methods. Antimicrobial assays over a wide range of bacterial strains are extensively surveyed, and wound-healing studies are finally considered to provide a comprehensive assessment framework. While early results are promising, a systematic and standardised testing procedure for the comparison of antibacterial properties is still lacking, partly because of a not-yet fully understood antimicrobial mechanism. This work, therefore, allowed, on one hand, the determination of the best strategies for the design, engineering, and application of n-ZnO-BNC, and, on the other hand, the identification of the current challenges and opportunities for future research
Dual-Band Integrated Antennas for DVB-T Receivers
An overview on compact Planar Inverted-F Antennas (PIFAs) that are suitable for monitor-equipped devices is presented. In particular, high efficiency PIFAs (without any dielectric layer) with a percentage bandwidth (%BW) greater than 59% (470–862 MHz DVB-T band) are considered. In this context, two PIFA configurations are reviewed, where a dual-band feature has been obtained, in the 3300–3800 MHz (14% percentage bandwidth) WiMAX and 2400–2484 MHz (2.7% percentage bandwidth) WLAN IEEE 802.11b,g frequency bands, respectively, to also guarantee web access to on-demand services. The two PIFAs fill an overall volume of  mm3 and  mm3, respectively. They are composed of a series of branches, properly dimensioned and separated to generate the required resonances. Finally, to show the extreme flexibility of the previous two configurations, a novel dual-band L-shape PIFA has been designed. A reflection coefficient less than −6 dB and −10 dB and an antenna gain of around 2 dBi and 6.3 dBi have been obtained in the 470–862 MHz DVB-T band and the 2400–2484 MHz WLAN band, respectively. The L-shape PIFA prototype can be obtained by properly cutting and folding a single metal sheet, thus resulting in a relatively low-cost and mechanically robust antenna configuration
Geomorphological map of the Lipari volcanic island (Aeolian Archipelago – Italy)
A 1:10,000-scale geomorphological map of the Lipari volcanic island (Aeolian Archipelago – Italy) is presented in this paper. The associated map, which includes volcanic and epivolcanic landforms, is obtained combining the available geological information with data derived from the analysis of a digital terrain model, integrated with aerial photographic observations and field surveys. The map shows that the location of the main volcanic morphologies is strongly controlled by local tectonic structures striking NNW-SSE, while the epivolcanic morphologies are mainly related to the continuous uplift induced by the prevalence of regional tectonic processes. The aim of this work is to provide an improved geomorphological map, with a reasonably comprehensive overview of the landforms present in the most densely populated island of the Aeolian Archipelago. This map can be also used as a support for future studies of land management on the island
Davison, Frederick
URSI International Symposium on Electromagnetic Theory (EMTS) (2019. San Diego)This paper presents the state-of-the-art on the synthesis techniques and technologies of the antennas for short-range radio links, when specific focusing/shaping of the radiated field in one or more regions close to the antenna itself (inside the antenna radiative near-field region) is required
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