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Auralization is a suitable method for the subjective evaluation of environmental noise. Due to its complexity, the plausible and immersive acoustic representation of outdoor scenarios in urban environments is an ongoing field of research. This work presents the design and implementation of a vehicle pass-by noise model with application in a real-time environmental noise auralization. The pass-by noise sources are implemented by procedural audio syntheses of engine and road-tyre noise with according directivities. In an audiovisual demonstration, the resulting source model is auralized considering the sound propagation phenomena in a virtual urban environment using the Virtual Acoustics framework.

Aggregates formed between organo-phosphoric acids and imine bases in aprotic solvents are the reactive intermediates in Brønsted acid organo-catalysis. Due to the strong hydrogen-bonding interaction of the acids in solution, multiple homo- and heteroaggregates are formed with profound effects on catalytic activity. Yet, due to the similar binding motifs-hydrogen-bonds-it is challenging to experimentally quantify the abundance of these aggregates in solution. Here we demonstrate that a combination of nuclear magnetic resonance (NMR) and dielectric relaxation spectroscopy (DRS) allows for accurate speciation of these aggregates in solution. We show that only by using the observables of both experiments heteroaggregates can be discriminated with simultaneously taking homoaggregation into account. Comparison of the association of diphenyl phosphoric acid and quinaldine or phenylquinaline in chloroform, dichloromethane, or tetrahydrofuran suggests that the basicity of the base largely determines the association of one acid and one base molecule to form an ion-pair. We find the ion-pair formation constants to be highest in chloroform, slightly lower in dichloromethane and lowest in tetrahydrofuran, which indicates that the hydrogen-bonding ability of the solvent also alters ion-pairing equilibria. We find evidence for the formation of multimers, consisting of one imine base and multiple diphenyl phosphoric acid molecules for both bases in all three solvents. This subsequent association of an acid to an ion-pair is however little affected by the nature of the base or the solvent. As such our findings provide routes to enhance the overall fraction of these multimers in solution, which have been reported to open new catalytic pathways.

In the context of acoustic urban planning, the use of noise mappings is a worldwide well-established practice. Therefore, the noise levels in an urban environment are calculated based on models of the sound sources, models of the physical sound propagation effects and the position of the receivers in the area of interest. However, the noise mapping method is limited to sound levels in frequency bands due to missing temporal and spectral information of the sound signals. This, in turn, leads to missing information about the qualitative sound properties, as they can be evaluated in psychoacoustic parameters. Beyond the scope of the classical noise mapping, auralization and physically-based simulation of sound fields can be applied to urban scenarios in the context of urban soundscape analysis. By supporting the auralization technology with a visual counterpart of the urban space, a plausible virtual representation of a real environment can be achieved. The presented framework combines the possibilities of the open-source auralization tool Virtual Acoustics with 3D visualization. In order to enable studies with natural human response or for public communication of urban design projects, those virtual scenes can be either reproduced with immersive technologies—such head-mounted displays (HMD)—or using online video platforms and traditional playback devices. The paper presents an overview of what physical principles can already be simulated, which technological considerations need to be taken into account, and how to set up such environment for auralization and visualization of urban scenes. We present the framework by the case study of IHTApark.

International audience; This essay’s aim is to present the current state of knowledge about the origins of the Roman town of Metz/Divodurum. In order to arrive at this, the literary sources and the results of urban archaeological excavations are used. The main research in the urban centre will be described, following a chronological and topographical rationale (Haut de Sainte-Croix hill, Citadelle hill, Outre-Seille area, Pontiffroy). The assumption being that the Roman town grew on the location of the oppidum (Haut de Sainte-Croix hill) with almost no interruption after the La Tène occupation, attention was focused on two areas which have been the object of recent excavations (Place de la République, excavated in 2009, the Citadelle hill and Paille-Maille Street excavated in 2012 in the Pontiffroy area) to offer instances for comparison. The data gathered give an illustration of the different kinds of housing and an evocation of the urban development and of the city’s limits after the Conquest.; L’objectif de cet article est de donner un état des connaissances sur les origines de la ville romaine de Metz/Divodurum. Pour y parvenir, les sources littéraires et le résultat des fouilles archéologiques urbaines sont employés. Les principales recherches dans le noyau urbain seront décrites en suivant une logique chronologique et topographique (colline du Haut de Sainte-Croix, colline de la Citadelle, secteur Outre-Seille, Pontiffroy). Le postulat étant que la ville romaine se développe à l’emplacement de l’oppidum (colline du Haut de Sainte-Croix) quasiment sans interruption depuis l’occupation laténienne, l’attention a été portée sur deux quartiers qui ont fait l’objet de fouilles récentes (place de la République, fouillée en 2009 sur la colline de la Citadelle et rue Paille-Maille, fouillée en 2012 dans le quartier du Pontiffroy) afin d’offrir des éléments de comparaison. Les données recueillies permettent d’illustrer les formes de l’habitat et d’évoquer le développement urbain et les limites de ville après la Conquête.