118 research outputs found
3D Virtual Microphone System - Sonda Microfonica ad Elevata Direttivita'
No full textSono descritte la teoria del nuovo sistema di ripresa e registrazione multicanale basato su 32 capsule posizionate su una sonda sferica e alcune applicazioni pratiche.
Con questo sistema si possono sintetizzare in tempo reale fino a 7 microfoni virtuali potendo scegliere dinamicamente la loro direttività (partendo da un omnidirezionale, passando ad un cardioide standard e arrivando ad un cardioide di ordine 6 ultradirettivo) e la loro posizione spaziale.
Un'interfaccia grafica ne permette il posizionamento ed il movimento su un'immagine video a 360°.
Il sistema è basato su un nuovo approccio matematico al calcolo della matrice di filtri FIR da convolvere in tempo reale con il segnale proveniente dalle capsule microfoniche; il tempo di latenza è ridotto grazie ad un processore di convoluzione partizionato
Sistema 3DVMS: da dove arriviamo...dove andiamo
No full textE' da decenni che si pensava ad un sistema audio che si comportasse come lo zoom di una telecamera, ovvero, non avvicinare il microfono a/l'attore, ma avvicinare la voce de/l'attore al microfono, senza che i due si muovessero! Si è riusciti nell'intento, e si sono ottenute evoluzioni da quel primo vagito
di idea, come il poter posizionare virtualmente i microfoni nello spazio, o il poter agganciare un soggetto con il microfono virtuale ma senza utilizzare
apparati hardware, oppure poter rifare ex-novo in postproduzione il lavoro eseguito in diretta, avendo a disposizione il grezzo della registrazione audio.
Ora il progetto a cui si pensa è più ambizioso: aumentare il numero di microfoni virtuali, cambiare l 'elettronica di riconoscimento del multiplex che
viaggia sul cavo ethernet, in poche parole cambiare la filosofia di utilizzo e del Sistema 30 VMS, che havisto la luce solo pochi anni fa
Habitat preference and flowering-time variation contribute to reproductive isolation between diploid and autotetraploid Anacamptis pyramidalis
No full textTetraploid lineages are typically reproductively isolated from their diploid ancestors by post-zygotic isolation via triploid sterility. Nevertheless, polyploids often also exhibit ecological divergence that could contribute to reproductive isolation from diploid ancestors. In this study, we disentangled the contribution of different forms of reproductive isolation between sympatric diploid and autotetraploid individuals of the food-deceptive orchid Anacamptis pyramidalis by quantifying the strength of seven reproductive barriers: three prepollination, one post-pollination prezygotic and three post-zygotic. The overall reproductive isolation between the two cytotypes was found very high, with a preponderant contribution of two prepollination barriers, that is phenological and microhabitat differences. Although the contribution of post-zygotic isolation (triploid sterility) is confirmed in our study, these results highlight that prepollination isolation, not necessarily involving pollinator preference, can represent a strong component of reproductive isolation between different cytotypes. Thus, in the context of polyploidy as quantum speciation, that generates reproductive isolation via triploid sterility, ecological divergence can strengthen the reproductive isolation between cytotypes, reducing the waste of gametes in low fitness interploidy crosses and thus favouring the initial establishment of the polyploid lineage. Under this light, speciation by polyploidy involves ecological processes and should not be strictly considered as a nonecological form of speciation
Carbon Nanomaterials in Electrochemical Detection
No full textHigh surface-to-volume ratio, high conductivity and electrocatalytic properties are some of the most interesting characteristics of carbon nanomaterials. Such exceptional properties have found a strong application in the field of electrochemical sensing. In this chapter we present the great relevance of the introduction of carbon nanomaterials, such as carbon nanotubes and graphene, for the development of new electrochemical sensors and biosensors. The possibility to exploit carbon nanomaterials for direct electrochemical sensing is illustrated. Furthermore, the easy modification of carbon materials with biomolecules enables the development of sophisticated and ultra-sensitive electrochemical sensors and biosensors for a plethora of important analytes and biomolecules, from DNA to cancer biomarkers. The possibility of coupling nanocarbon-based electrochemical sensors as detectors in separation techniques is briefly introduced. The most typical applications are described
Putative Signals of Generalist Plant Species Adaptation to Local Pollinator Communities and Abiotic Factors
No full textThe reproductive success of flowering plants with generalized pollination systems is influenced by interactions with a diverse pollinator community and abiotic factors. However, knowledge about the adaptative potential of plants to complex ecological networks and the underlying genetic mechanisms is still limited. Based on a pool-sequencing approach of 21 natural populations of Brassica incana in Southern Italy, we combined a genome-environmental association analysis with a genome scan for signals of population genomic differentiation to discover genetic variants associated with the ecological variation. We identified genomic regions putatively involved in the adaptation of B. incana to the identity of local pollinator functional categories and pollinator community composition. Interestingly, we observed several shared candidate genes associated with long-tongue bees, soil texture, and temperature variation. We established a genomic map of potential generalist flowering plant local adaptation to complex biotic interactions, and the importance of considering multiple environmental factors to describe the adaptive landscape of plant populations
Speech Quality Improvement of TV-Sets for Hearing-Impaired Older Adults
No full textFlat TV-sets sacrifice space for built-in loudspeakers and this implies a degradation of the speech quality, especially for hearing-impaired older adults. Many elderly people report having difficulty understanding speech on TV, even with hearing aids. In the study, a Transfer Function (TF) that improves the listening experience for the above categories of listeners is validated for Rai, the Italian TV broadcasting company. A Digital Audio Optimizer dynamically equalizes the sound level, in real-time, before the transmission to the broadcasting tower. It implements a TF that amplifies the frequency range between 14, which is more important for speech intelligibility, with a particular boosting of the one-third octave band of 4. Subjective tests of the proposed TF have been carried out in a laboratory in compliance with the standard ITU-R BS.1116-3 with 31 hearing-impaired older adults and a commercial flat-screen TV-set. Results showed a statistically significant slight improvement in the perceived audio quality of 24.3%, over three genres, i.e.", Speech"", Singing and Music" and "Sport". This work follows a previous study on 72 normal-hearing subjects where the same methodology was applied, which involved three commercial flat-screen TV-sets and the same genres. The perceived audio quality was judged improved by the 25.3% on average
Conical nanopore membranes: solvent shaping of nanopores
No full textWe have undertaken a systematic investigation of the influence of ethanol on
the shape of conical pores produced by the track-etch technique in
poly(ethylene terephthalate) films. We have found that the cone angle of the
conical nanopore generated is dependent on the amount of ethanol present in
an alkaline etching solution. By varying the percentage of ethanol in the etch
solution, precise control over the geometry of the conical nanopore and
nanomaterials templated within these pores can be attained. We prove this by
plating gold nanocones within the various conical nanopores prepared,
dissolving the membrane to liberate the nanocones, and imaging the
nanocones using scanning electron microscopy. The results of these
investigations are reported here
The assembly of two complete chloroplast genome in the orchid genus Ophrys reveals a phylogenetic pattern for the NDHF gene loss
No full text- …
