Acoustic positioning using multiple microphone arrays

Passive acoustic techniques are presented to solve the localization problem of a sound source in three-dimensional space using off-the-shelf hardware. Multiple microphone arrays are employed, which operate independently, in estimating the direction of arrival of sound, or, equivalently, a direction vector from the array's geometric center towards the source. Direction vectors and array centers are communicated to a central processor, where the source is localized by finding the intersection of the direction lines defined by the direction vectors and the associated array centers. The performance of the method in the air is demonstrated experimentally and compared with a state-of-the-art method that requires centralized digitization of the signals from the microphones of all the arrays.     

Microstuctural analysis and determination of PM10 emission sources in an industrial Mediterranean city

Scientists are interested in knowing more about the control of sources which contribute to environmental pollution. Air pollution has two main sources: anthropogenic and natural sources. The natural contributions to environmental pollution can be assessed, but cannot be totally controlled. while the emissions from the anthropogenic sources can be controlled. These air pollutants can be dispersed and transferred by winds in the atmosphere. The focus area of this study is the Mediterranean basin. The most important winds in this area are the land and sea breezes. Scanning Electron Microscopy (SEM) was applied to characterize the morphology of the PM10 samples in order to identify possible emission sources for the occuring pollution. Energy Dispersive X-ray Spectroscopy (EDS) was performed for the elemental analysis and chemical characterization of the PM10 samples. The analysis showed that the PM10 samples can be divided into three different groups: the samples containing mineral phases, the compounds from combustion processes and the particles emitted from high-temperature processes.      

Studying Physiological Synchrony in Couple Therapy through Partial Directed Coherence: Associations with the Therapeutic Alliance and Meaning Construction

In line with the growing recognition of the role of embodiment, affect and implicit processes in psychotherapy, several recent studies examine the role of physiological synchrony in the process and outcome of psychotherapy. This study aims to introduce Partial Directed Coherence (PDC) as a novel approach to calculating psychophysiological synchrony and examine its potential to contribute to our understanding of the therapy process. The study adopts a single-case, mixed-method design and examines physiological synchrony in one-couple therapy in relation to the therapeutic alliance and a narrative analysis of meaning construction in the sessions. Interpersonal Physiological Synchrony (IPS) was calculated, via a windowed approach, through PDC of a Heart Rate Variability-derived physiological index, which was measured in the third and penultimate sessions. Our mixed-method analysis shows that PDC quantified significant moments of IPS within and across the sessions, modeling the characteristics of interpersonal interaction as well as the effects of therapy on the interactional dynamics. The findings of this study point to the complex interplay between explicit and implicit levels of interaction and the potential contribution of including physiological synchrony in the study of interactional processes in psychotherapy.     

Nanomaterials in Cementitious Composites: An Update

This review is an update about the addition of nanomaterials in cementitious composites in order to improve their performance. The most common used nanomaterials for cementitious materials are carbon nanotubes, nanocellulose, nanographene, graphene oxide, nanosilica and nanoTiO₂. All these nanomaterials can improve the physical, mechanical, thermal and electrical properties of cementitious composites, for example increase their compressive and tensile strength, accelerate hydration, decrease porosity and enhance fire resistance. Cement based materials have a very complex nanostructure consisting of hydration products, crystals, unhydrated cement particles and nanoporosity where traditional reinforcement, which is at the macro and micro scale, is not effective. Nanomaterials can reinforce the nanoscale, which wasn’t possible heretofore, enhancing the performance of the cementitious matrix.     

Studies of an Fe9 tridiminished icosahedron

The synthesis and structural characterization of a nonanuclear FeIII cage complex is reported. The nine iron centers in [Fe9(mu3-O)4(O3PPh)3(O2CCMe3)13] lie on the vertices of an incomplete icosahedron, with the P atoms of triphenylphosphonate at the other three vertices. The paramagnetic core therefore describes a tridiminished icosahedron. Magnetic studies suggest an S=1/2 ground state for the molecule. Analysis of exchange paths and the susceptibility data point to the interpretation that the cluster can be divided into two nearly decoupled sections: an {Fe6O3} section, with an S=0 ground state, in which three oxo-centered triangles bound a central triangle that is not oxo-centered; and an {Fe3O} triangle with S=1/2. The analysis of the susceptibility data leads to a Heisenberg model based on three significant antiferromagnetic exchange interactions, with values of 173.7 cm-1 in the {Fe3O} triangle, and 30.9 and 19.1 cm-1 within the {Fe6O3} section, while the exchange between them is <1 cm-1. With these assignments, the theoretical low-temperature differential susceptibility is also in very good agreement with measurements up to 50 T. Magnetic measurements in the milli-kelvin range reveal striking hysteresis loops and magnetization reversals associated with a Landau-Zener-Stückelberg (LZS) transition as enhanced by the occurrence of a phonon bottleneck.     

Inference of a minimum size boolean function from examples by using a new efficient branch-and-bound approach

This paper deals with the problem of identifying a hidden Boolean function : 0, 1' 0, 1 from positive and negative examples. This problem is of paramount importance in many real life applications of artificial intelligence. The method proposed in this paper is based on a branch-and-bound approach. This approach is an expansion of some earlier work (Triantaphyllouet al., 1994). Computational results, comparing the new method with one based on Karmakar's interior point method, suggest that the new method is very efficient.     

Electronic and geometric structure analysis of neutral and anionic metal nitric chalcogens: The case of MNX series (M=Li,Na, Be and X=O,S, Se,Te)

Coupled cluster and multireference configuration approaches are employed to study the electronic and geometric structures of mono-coordinated complexes of lithium, sodium, and beryllium with nitric oxide and its isovalent NS, NSe, and NTe species. Ground and low-lying excited states were examined for both linear-bonded and side-bonded isomers. We show that the ionic M⁺NX⁻ (M=Li, Na, Be and X=O, S, Se, Te) picture is a more natural representation and can account for the symmetry of the low−lying electronic states as Σ⁻, Δ, and Σ⁺, the smaller excitation energies and the larger binding energies for heavier X. An additional electron binds to the positively charged Li and Na terminal creating stable anions. The electron affinity (EA) of LiNX and NaNX species is in the 0.5–0.8 eV range. Despite the negative EA of beryllium and the very small EA of NO, the BeNO molecule has an EA of ~1.0 eV, which is increased to ~1.5 eV for the heavier BeNX species. This is attributed to the fact that the additional electron goes to the beryllium end for BeNO but to a π(MN) π*(NX) orbital of the rest species. Our accurate results contradict previous findings and serve as a guide for future experimental studies. © 2019 Wiley Periodicals, Inc.