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Search Results: 1 - 10 of 3012 matches for " Daniele Foresti "
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Acoustophoretic Waltz: a Contactless Exothermal Reaction
Daniele Foresti,Dimos Poulikakos
Physics , 2013, DOI: 10.1063/1.4893545
Abstract: The fluid dynamics video shows the acoustophoretic handling of a metal sodium chunks and a water droplets before, during and after mixing. The violent exothermal reaction between solid and liquid introduces an additional phase (hydrogen gas). We developed a unique concept for using ultrasound to stably levitated and move along a plane multiple objects in air, independently from their electromagnetic nature and aspect ratio. This contactless material handling can be extended to hazardous, chemical or radioactive samples.
Exploiting a Geometrically Sampled Grid in the SRP-PHAT for Localization Improvement and Power Response Sensitivity Analysis
Daniele Salvati,Carlo Drioli,Gian Luca Foresti
Computer Science , 2015,
Abstract: The steered response power phase transform (SRP-PHAT) is a beamformer method very attractive in acoustic localization applications due to its robustness in reverberant environments. This paper presents a spatial grid design procedure, called the geometrically sampled grid (GSG), which aims at computing the spatial grid by taking into account the discrete sampling of time difference of arrival (TDOA) functions and the desired spatial resolution. A new SRP-PHAT localization algorithm based on the GSG method is also introduced. The proposed method exploits the intersections of the discrete hyperboloids representing the TDOA information domain of the sensor array, and projects the whole TDOA information on the space search grid. The GSG method thus allows to design the sampled spatial grid which represents the best search grid for a given sensor array, it allows to perform a sensitivity analysis of the array and to characterize its spatial localization accuracy, and it may assist the system designer in the reconfiguration of the array. Experimental results using both simulated data and real recordings show that the localization accuracy is substantially improved both for high and for low spatial resolution, and that it is closely related to the proposed power response sensitivity measure.
Arnaldo Sarti,Eugenio Foresti
Holos Environment , 2009,
Abstract: This paper presents and discusses the potential for use of pilot-scale anaerobic sequencing batch biofilm reactors (ASBBR) for the treatment of industrial wastewater containing high sulfate concentration. The pilot-scale ASBBR reactor (total volume=1.2 m3) containing biomass immobilized in inert support (mineral coal) was operated at sulfate loading rates varying from 0.15 to 1.90 kgSO4-2/cycle (cycle of 48h) corresponding to sulfate concentrations of 0.25 to 3.0 gSO4-2.L-1. Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. The mean sulfate removal efficiencies remained in the range of 88 to 92% in the several sulfate concentrations obtained from 92 operational cycles. As post-treatment unit for the generated effluents by the sulfate reduction was used another reactor ASBBR in pilot-scale (total volume=385,0 L) with same inert support for biomass immobilization and different granulometry. The mean COD removal (mean influent=1450 mg.L-1) achieved 88% and total sulfide concentrations (H2S, HS , S2 ) remained in the range of 41 to 71 mg.L-1 during the 35 operational cycles of 48 h. The results demonstrated that the use of ASBBR reactors is an alternative potential for the sulfate removal and as post-treatment of generated effluent. = Este trabalho apresenta e discute o potencial de uso de reatores anaeróbios operados em bateladas seqüenciais com biomassa imobilizada (ASBBR), em escala piloto, no tratamento de água residuária industrial contendo elevadas concentra es de sulfato. No ASBBR, com volume total de 1,2 m3, preenchido com carv o mineral (meio suporte) foram aplicadas cargas de sulfato de 0,15 a 1,90 kg/ciclo com dura o de ciclo de 48 h, correspondendo, respectivamente, às concentra es de sulfato no afluente de 0,25 a 3,0 g.L-1. O esgoto sanitário e etanol foram usados como doadores de elétrons para a redu o do sulfato. As eficiências médias na redu o de sulfato ficaram entre 88 e 92% nos 92 ciclos operacionais. Como pós-tratamento dos efluentes gerados pela redu o de sulfato empregou-se outro reator ASBBR com volume total de 385,0 L e mesmo meio suporte para imobiliza o da biomassa, mas com diferente granulometria. A remo o média de DQO (valor médio afluente: 1450 mg.L-1) foi de 88%, enquanto as concentra es de sulfetos totais (H2S, HS , S2 ) mantiveram-se entre a faixa de 41 e 71 mg.L-1 nos 35 ciclos operacionais de 48h. Os resultados obtidos permitiram concluir que o uso de reatores ASBBR constitui-se em potencial alternativa tanto para a remo o de sulfatos, como no pós-tratamento dos efluentes gerados.
A Multimodal Learning System for Individuals with Sensorial, Neuropsychological, and Relational Impairments
Sergio Canazza,Gian Luca Foresti
Journal of Sensors , 2013, DOI: 10.1155/2013/564864
Abstract: This paper presents a system for an interactive multimodal environment able (i) to train the listening comprehension in various populations of pupils, both Italian and immigrants, having different disabilities and (ii) to assess speech production and discrimination. The proposed system is the result of a research project focused on pupils with sensorial, neuropsychological, and relational impairments. The project involves innovative technological systems that the users (speech terabits psychologists and preprimary and primary schools teachers) could adopt for training and assessment of language and speech. Because the system is used in a real scenario (the Italian schools are often affected by poor funding for education and teachers without informatics skills), the guidelines adopted are low-cost technology; usability; customizable system; robustness. 1. Introduction Learning systems providing user interaction within physical spaces have been carried out over the years. However the high cost and the high complexity of the technologies used have always implied that their use by pupils in real context was limited to occasional visits or short periods of experimentation. Our aim is to provide an interactive multimodal environment (developed in C++) that can be integrated with the ordinary educational activities within the school. For this purpose, we use common technologies—such as webcams, microphones, and Microsoft Kinect sensors—in order (i) to provide tools that allow teachers to adapt or create autonomously the educational activities content to be carried out with the system and (ii) to implement a user interface for the management software that does not require specific computer skills. Our system implements the five different types of interaction stated by Moreno and Mayer [1]: (1) dialogue, (2) control, (3) manipulation, (4) search, and (5) navigation. Indeed, these five levels are very familiar during the everyday learning activity. Here are some examples: (1) a comparison/oral discussion in which the exchange of information is not unilateral, but the opportunities to the students to ask questions and express their opinions are given influencing the content of the lesson; (2) oral exposure in which the student has the ability to control the speed and to stop the explanation in order to benefit from the educational content at their own pace; (3) a scientific experiment that leaves the possibility for the student to test different parameters and see what happens; (4) the ability to independently seek information on a certain subject within a
Ten Years of the Central Italy Electromagnetic Network (CIEN) Continuous Monitoring  [PDF]
Cristiano Fidani, Daniele Marcelli
Open Journal of Earthquake Research (OJER) , 2017, DOI: 10.4236/ojer.2017.62004
Abstract: A test is being realised by means of a network of wide band electromagnetic detectors that continuously records the electric components of the electromagnetic field, ranging from a few of Hz to tens of kHz. The network has been operating in central Italy for more than ten years. The recorded signals from this network have been analysed in real time as well as their power spectrum contents. Time/frequency data have been saved for further analysis. The spectral contents have evidenced very distinct power spectrum signatures in ELF band that increase in intensity when strong seismic activity occurs near the stations, for example, at the time of Amatrice (M = 6) and Norcia (M = 6.5) earthquakes in 2016 when ten stations were operative, at the time of the Emilia (M = 6) earthquakes in 2012 when nine stations were operative, and at the time of the L’Aquila (M = 6.3) earthquakes in 2009 when only two stations were operative. Strong signals were also detected during the moderate Ancona (M = 5) earthquake in 2013 and by the recently installed Avigliano Umbro, Città di Castello and Gubbio stations in the Umbria region, during small seismic swarms (2 < M < 4) between 2013 and 2014. CIEN is presently composed of 16 stations and collect data from a multidisciplinary instrumentation.
Monitoring and Identification of the Seismically Isolated “Our Lady of Tears” Shrine in Syracuse  [PDF]
Daniele Losanno, Mariacristina Spizzuoco
Open Journal of Civil Engineering (OJCE) , 2018, DOI: 10.4236/ojce.2018.84028
Abstract: This paper describes the installation and management of the monitoring system of the “Our Lady of Tears Shrine” in Syracuse, whose dome is an imposing r.c. and prestressed r.c. structure of about 22,000 ton that was seismically isolated by flat sliding devices with hysteretic dampers. The monitoring system, representing an upgrading and improvement of an old system never made working, has some innovative features, because it allows to manage with the same dedicated hardware and software both the slow (thermal variations, relative humidity, wind direction and velocity) and the fast acquisitions (dynamic vibrations by wind and earthquake). The monitoring system was inserted among those structures maintained and controlled by the Seismic Observatory of Structures of the National Department of Civil Protection. Some records of low magnitude earthquakes allowed to validate the correct behaviour of the whole structure, as well as to make a dynamic identification of the complex construction and to calibrate a detailed finite element model of the Sanctuary, thus predicting isolators’ behaviour under design earthquake.
Self gravitating cosmic strings and the Alexandrov's inequality for Liouville-type equations
Daniele Bartolucci,Daniele Castorina
Mathematics , 2014,
Abstract: Motivated by the study of self gravitating cosmic strings, we pursue the well known method by C. Bandle to obtain a weak version of the classical Alexandrov's isoperimetric inequality. In fact we derive some quantitative estimates for weak subsolutions of a Liouville-type equation with conical singularities. Actually we succeed in generalizing previously known results, including Bol's inequality and pointwise estimates, to the case where the solutions solve the equation just in the sense of distributions. Next, we derive some \uv{new} pointwise estimates suitable to be applied to a class of singular cosmic string equations. Finally, interestingly enough, we apply these results to establish a minimal mass property for solutions of the cosmic string equation which are \uv{supersolutions} of the singular Liouville-type equation.
A global existence result for a Keller-Segel type system with supercritical initial data
Daniele Bartolucci,Daniele Castorina
Mathematics , 2015,
Abstract: We consider a parabolic-elliptic Keller-Segel type system, which is related to a simplified model of chemotaxis. Concerning the maximal range of existence of solutions, there are essentially two kinds of results: either global existence in time for general subcritical ($\|\rho_0\|_1<8\pi$) initial data, or blow--up in finite time for suitably chosen supercritical ($\|\rho_0\|_1>8\pi$) initial data with concentration around finitely many points. As a matter of fact there are no results claiming the existence of global solutions in the supercritical case. We solve this problem here and prove that, for a particular set of initial data which share large supercritical masses, the corresponding solution is global and uniformly bounded.
A tritrophic signal that attracts parasitoids to host-damaged plants withstands disruption by non-host herbivores
Matthias Erb, Nicolas Foresti, Ted CJ Turlings
BMC Plant Biology , 2010, DOI: 10.1186/1471-2229-10-247
Abstract: The parasitoid Cotesia marginiventris strongly preferred volatiles of plants infested with its host S. littoralis. Overall, the volatile emissions induced by S. littoralis and E. variegatus were similar, but higher levels of certain wound-released compounds may have allowed the wasps to specifically recognize plants infested by hosts. Expression levels of defense marker genes and further behavioral bioassays with the parasitoid showed that neither the physiological defense responses nor the attractiveness of S. littoralis infested plants were altered by simultaneous E. variegatus attack.Our findings imply that plant defense responses to herbivory can be more robust than generally assumed and that ensuing volatiles convey specific information about the type of herbivore that is attacking a plant, even in complex situations with multiple herbivores. Hence, the results of this study support the notion that herbivore-induced plant volatiles may be part of a plant's indirect defense stratagem.Predators and parasitoids are important natural enemies of herbivorous insects. By reducing the abundance of herbivores, they can help protect plants from damage. Parasitoids in particular can use herbivore-induced plant volatiles (HIPVs) as host-searching cues [1,2]. Such volatile-mediated tritrophic interactions have a considerable potential to shape ecosystem dynamics [3], but it remains unclear to what extend the plant signals are emitted by the plant to specifically attract natural enemies of herbivores [4]. If HIPVs are indeed emitted by the plant to attract the third tropic level, specificity of the signals should be an important aspect of the interactions [5]. This is particularly relevant under natural conditions, where plants are often attacked by non-hosts or by multiple herbivores simultaneously. While specialist parasitoids can distinguish between plants attacked by hosts and plants attacked by non-hosts using HIPV cues [6], the impact of non-hosts feeding on the same p
Cytotaxonomic diagnosis of Trichomycterus diabolus (Teleostei: Trichomycteridae) with comments about its evolutionary relationships with co-generic species
Torres, Rodrigo A.;Oliveira, Claudio;Foresti, Fausto;
Neotropical Ichthyology , 2004, DOI: 10.1590/S1679-62252004000300003
Abstract: the karyotype and the ag-nor location of a sample of trichomycterus diabolus collected in the córrego hortel? (botucatu, s?o paulo, brazil) are described. the species exhibited 2n=56 chromosomes (42 metacentrics, 12 submetacentrics and 2 subtelocentrics) and the nucleolus organizing region located near to the centromere on the long arm of the largest metacentric pair. the presence of 2n=56 chromosomes in t. diabolus is an interesting characteristic since until now all cis-andean species karyotyped presented 2n=54 chromosomes while almost all trans-andean species presented different diploid numbers. the possible origin of this unexpected karyotypic form is discussed.
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