Accurate sound synthesis of 3D object collisions in interactive virtual scenarios

Questa tesi affronta lo studio di algoritmi efficienti per la sintesi di suoni risultanti dalla collisione di oggetti generici, partendo da una descrizione fisica del problema. L'obiettivo della ricerca e' lo sviluppo di strumenti in grado di aumentare l'accuratezza del feedback uditivo in ambienti di realta' virtuale attraverso un approccio basato sulla fisica, senza il bisogno quindi di far riferimento a suoni pre-registrati. Data la loro versatilita' nel trattare geometrie complesse, i metodi agli elementi finiti (FEM) sono stati scelti per la discretizzazione spaziale di generici risonatori tridimensionali. Le risultanti equazioni discrete sono riarrangiate in modo da disaccoppiare i modi normali del sistema tramite l'utilizzo di tecniche di Analisi e Sintesi Modale. Queste tecniche, infatti, portano convenientemente ad algoritmi computazionalmente efficienti per la sintesi del suono. Implementazioni di esempio di tali algoritmi sono state sviluppate facendo uso solo di software open-source: questo materiale a corredo della tesi permette una migliore riproducibilita' dei risultati di questa tesi da parte di ricercatori aventi una preparazione nel campo della sintesi audio. I risultati originali presenti in questo lavoro includono: i tecniche efficienti basate sulla fisica che aiutano l'implementazione in tempo reale di algoritmi di sintesi del suono su hardware comune; ii un metodo per la gestione efficiente dei dati provenienti da analisi FEM che, assieme ad un modello espressivo per la dissipazione, permette di calcolare l'informazione caratterizzante un oggetto risonante e salvarla in una struttura dati compatta iii una trasformazione nel dominio discreto del tempo su due diverse rappresentazioni nello spazio degli stati di filtri digitali del secondo ordine, che permette il calcolo esatto di variabili derivate come la velocita' e l'energia di un risonatore anche quando semplici realizzazioni a soli poli sono impiegate i un'efficiente realizzazione multirate di un banco parallelo di risonatori, derivata usando una suddivisione con Quadrature-Mirror-Filters (QMF). Confrontata con lavori simili presenti in letteratura, questa realizzazione permette l'uso di eccitazione nonlineare in feedback per un banco di risonatori in multirate: l'idea chiave consiste nello svolgere un cambio di stato adattivo nel banco di risonatori, muovendo i risonatori dalla frequenza di campionamento elevata, usata per il processamento della fase transiente, ad un insieme di sottofrequenze ridotte usate durante l'evoluzione in stato libero del sistema.This thesis investigates efficient algorithms for the synthesis of sounds produced by colliding objects, starting from a physical description of the problem. The objective of this investigation is to provide tools capable of increasing the accuracy of the synthetic auditory feedback in virtual environments through a physics-based approach, hence without the need of pre-recorded sounds. Due to their versatility in dealing with complex geometries, Finite Element Methods (FEM) are chosen for the space-domain discretization of generic three-dimensional resonators. The resulting state-space representations are rearranged so as to decouple the normal modes in the corresponding equations, through the use of Modal Analysis/Synthesis techniques. Such techniques, in fact, conveniently lead to computationally efficient sound synthesis algorithms. The whole mathematical treatment develops until deriving such algorithms. Finally, implementation examples are provided which rely only on open-source software: this companion material guarantees the reproducibility of the results, and can be handled without much effort by most researchers having a background in sound processing. The original results presented in this work include: i efficient physics-based techniques that help implement real-time sound synthesis algorithms on common hardware; ii a method for the efficient management of FEM data which, by working together with an expressive damping model, allows to pre-compute the information characterizing a resonating object and then to store it in a compact data structure; iii a time-domain transformation of the state-space representation of second-order digital filters, allowing for the exact computation of dependent variables such as resonator velocity and energy, even when simple all-pole realizations are used; iv an efficient multirate realization of a parallel bank of resonators, which is derived using a Quadrature-Mirror-Filters (QMF) subdivision. Compared to similar works previously proposed in the literature, this realization allows for the nonlinear feedback excitation of a multirate filter bank: the key idea is to perform an adaptive state change in the resonator bank, by switching the sampling rate of the resonators from a common highest value, used while processing the initial transient of the signals at full bandwidth, to a set of lower values in ways to enable a multirate realization of the same bank during the steady state evolution of the signals

Designing on subjective tolerance to approximated piano reproductions

Results from three experiments are presented, showing that the perceived acoustic and vibrotactile quality of a reproduced piano does not require models simulating every aspect of the original instrument with great accuracy. It was found that high-quality loudspeaker array passive listening at the pianist's position admits distortions of the sound field. Furthermore, pianists during playing seem to compensate for errors in the auditory scene description. Finally, they are particularly sensitive to the existence of vibrotactile feedback on their fingers meanwhile tolerant about the precision with which this feedback is reproduced. Based on these results we are currently working on a lightweight portable physics-based digital piano design, that should improve upon the experience a pianist with no keyboards at hand makes when interacting with a touch-screen piano software running on smartphones and laptops

Ce-MBGs Loaded with Gentamicin: Characterization and In Vitro Evaluation

Mesoporous Bioactive Glasses (MBGs) are biomaterials widely used in tissue engineering, particularly for hard tissue regeneration. One of the most frequent postoperative complications following a biomaterial surgical implant is a bacterial infection, which usually requires treatment by the systemic administration of drugs (e.g., antibiotics). In order to develop biomaterials with antibiotic properties, we investigated cerium-doped MBGs (Ce-MBGs) as in situ-controlled drug delivery systems (DDSs) of gentamicin (Gen), a wide spectrum antibiotic commonly employed against bacteria responsible of postoperative infections. Here we report the optimization of Gen loading on MBGs and the evaluation of the antibacterial properties and of retention of bioactivity and antioxidant properties of the resulting materials. The Gen loading (up to 7%) was found to be independent from cerium content, and the optimized Gen-loaded Ce-MBGs retain significant bioactivity and antioxidant properties. The antibacterial efficacy was verified up to 10 days of controlled release. These properties make Gen-loaded Ce-MBGs interesting candidates for simultaneous hard tissue regeneration and in situ antibiotic release

Sarcoma risk and dioxin emissions from incinerators and industrial plants: a population-based case-control study (Italy)

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Microbial inactivation efficiency of supercritical CO2drying process

Conventional drying of spices, as hot air treatment, often needs an additional downstream inactivation step to decrease the microbial load of the dried product and improve its microbial safety and microbial quality. In this regard, the present work explored the possibility to dry and decontaminate food in a single step using supercritical carbon dioxide (scCO(2)) as a drying agent. A case study was focused on the drying of herbs and the antimicrobial effects were evaluated on the naturally present microbiota. For this purpose, experiments were carried out on coriander leaves using a high pressure vessel at 10 MPa, at two different temperatures (40 and 50 degrees C) with drying time of 0 and 150 min to establish the influence of each parameter on the microbial inactivation. Yeasts and molds appeared to be the least resistant to scCO(2) as they could never be detected after the treatment (<2 log CFU/g). Mesophilic bacteria were also significantly reduced, up to 4 log CFU/g, but remained above the limit of quantification. The quality of the dried product was comparable with the quality of air-dried samples in terms of phenolic constituents. Overall, the results indicated that scCO(2) drying was a promising green drying technique combining both drying and microbial inactivation in a single step with a relevant impact on safety and costs

Sustainability, non-financial, integrated, and value reporting (extended external reporting) : a conceptual framework and an agenda for future research

PURPOSE : This paper aims to develop a conceptual framework for extended external reporting (EER) influences (EERI), including sustainability, non-financial, integrated and value reporting. Using the Environmental Legitimacy, Accountability, and Proactivity (ELAP) framework as the base, we modify its proposed concepts and linkages using relevant conceptual models, prior reviews and findings of recent studies on EER. This paper presents contributions of the special issue on “non-financial and integrated reporting, governance and value creation” and avenues for future research. DESIGN/METHODOLOGY/APPROACH : Drawing on relevant conceptual models, prior reviews and recent EER studies, we reframed the ELAP framework into a framework that theorises the factors that affects, or are affected by, EER. FINDINGS : The EERI framework poses relationships between and within proactivity, external verification, accountability and legitimacy. It also consolidates possible determinants and consequences of EER. The papers published in this special issue contribute further insights on factors that influence reporting practices, processes and suggestions for capturing and communicating value creation information, and the value of integrated reports and assurance to capital providers. ORIGINALITY/VALUE : Along with the insights provided by papers in this special issue, the conceptual framework can be used to theorise influences of EER and guide future research.https://www.emerald.com/insight/publication/issn/2049-372Xhj2023Accountin

Prevalence and prognostic impact of non-cardiac co-morbidities in heart failure outpatients with preserved and reduced ejection fraction: a community-based study

Aim: To assess adverse outcomes attributable to non-cardiac co-morbidities and to compare their effects by left ventricular ejection fraction (LVEF) group [LVEF <50% (heart failure with reduced ejection fraction, HFrEF), LVEF 6550% (heart failure with preserved ejection fraction, HFpEF)] in a contemporary, unselected chronic heart failure population. Methods and results: This community-based cohort enrolled patients from October 2009 to December 2013. Adjusted hazard ratio (HR) and the population attributable fraction (PAF) were used to compare the contribution of 15 non-cardiac co-morbidities to adverse outcome. Overall, 2314 patients (mean age 77 \ub110 years, 57% men) were recruited [n = 941 (41%) HFrEF, n = 1373 (59%) HFpEF]. Non-cardiac co-morbidity rates were similarly high, except for obesity and hypertension which were more prevalent in HFpEF. At a median follow-up of 31 (interquartile range 16\u201341) months, 472 (20%) patients died. Adjusted mortality rates were not significantly different between the HFrEF and HFpEF groups. After adjustment, an increasing number of non-cardiac co-morbidities was associated with a higher risk for all-cause mortality [HR 1.25; 95% confidence interval (CI) 1.10\u20131.26; P < 0.001], all-cause hospitalization (HR 1.17; 95% CI 1.12\u20131.23; P < 0.001), heart failure hospitalization (HR 1.28; 95% CI 1.19\u20131.38; P < 0.001), non-cardiovascular hospitalization (HR 1.16; 95% CI 1.11\u20131.22; P < 0.001). The co-morbidities contributing to high PAF were: anaemia, chronic kidney disease, chronic obstructive pulmonary disease, diabetes mellitus, and peripheral artery disease. These findings were similar for HFrEF and HFpEF. Interaction analysis yielded similar results. Conclusions: In a contemporary community population with chronic heart failure, non-cardiac co-morbidities confer a similar contribution to outcomes in HFrEF and HFpEF. These observations suggest that quality improvement initiatives aimed at optimizing co-morbidities may be similarly effective in HFrEF and HFpEF

Hydrodechlorination of Aroclor 1260 in aqueous two-phase mixture catalyzed by biogenerated bimetallic catalysts

The PCBs are known recalcitrant and toxic pollutants and significant values of contamination could be found in water. PCBs can be hydrodechlorinated using Pd-based catalysts and hydrogen, but the research to identify more efficient heterogeneous catalysts, able to work in an aqueous phase, less sensible to deactivation and easily removable at the end of the treatment, remains a considerable interesting goal. A strain of Klebsiella oxytoca, DSM 29614, known to produce a specific exopolysaccaride (EPS), was grown in different media with sodium citrate or with sodium citrate plus ferric citrate, as sole energy and carbon sources under anaerobic conditions. The cultures were amended with 50 mg of palladium as Pd(NO3)2 to generate Pd-EPS (Pd content 13%) or FePd-EPS (Pd content 8.4%; Fe 7.4%) species which were secreted from the cells, isolated by treatment with a cold ethanol solution (70%) and dried under vacuum as powders. The catalytic ability of these mono- and bi-metallic species was tested in the hydrodechlorination reaction of the Aroclor 1260 PCBs mixture under aqueous biphasic conditions. Here we demonstrate that the degree of PCBs hydrodechlorination is dependent by the nature of catalyst and of base used to neutralize HCl produced, the bimetallic species being more active and an organic base resulting more effective. Working with a substrate/catalyst 8/1 molar ratio, at 3 MPa H2 and 60°C in 20 h a significant removal of highly chl orinated PCBs was obtained under the best conditions. The result seems promising for remediation of groundwater contaminated with PCBs

Impact of reboxetine plus oxybutynin treatment for obstructive sleep apnea on cardiovascular autonomic modulation

The combination of noradrenergic (reboxetine) plus antimuscarinic (oxybutynin) drugs (reb-oxy) reduced obstructive sleep apnea (OSA) severity but no data are available on its effects on cardiac autonomic modulation. We sought to evaluate the impact of 1-week reb-oxy treatment on cardiovascular autonomic control in OSA patients. OSA patients were randomized to a double-blind, crossover trial comparing 4 mg reboxetine plus 5 mg oxybutynin to a placebo for OSA treatment. Heart rate (HR) variability (HRV), ambulatory blood pressure (BP) monitoring (ABPM) over 24 h baseline and after treatment were performed. Baroreflex sensitivity was tested over beat-to-beat BP recordings. 16 subjects with (median [interquartile range]) age 57 [51–61] years and body mass index 30 [26–36]kg/m2 completed the study. The median nocturnal HR was 65 [60–69] bpm at baseline and increased to 69 [64–77] bpm on reb-oxy vs 66 [59–70] bpm on placebo (p = 0.02). The mean 24 h HR from ABPM was not different among treatment groups. Reb-oxy administration was not associated with any modification in HRV or BP. Reb-oxy increased the baroreflex sensitivity and did not induce orthostatic hypotension. In conclusion, administration of reb-oxy did not induce clinically relevant sympathetic overactivity over 1-week and, together with a reduction in OSA severity, it improved the baroreflex function