1,721,045 research outputs found
Wave-like Correlations versus Path Detection: Another Form of Complementarity
No full textThe two main foundational issues of quantum mechanics that have been discussed from since the birth of the theory are, apart from the measurement problem, the wave particle duality and the EPR correlations. We propose an experiment which could throw new light on these features, which have always been object of separate investigations, stressing the existence of a deep connection between them.
Wave particle duality is a puzzle that has given rise to all logically possible interpretations: Bohr tried to cast the problem in terms of a complementary relation between a wave-like and a particle-like behaviour; Heisenberg, Born, Pauli and Jordan considered the wave function as a mere mathematical tool for calculating probabilities of observations; de Broglie attributed a simultaneous reality to both waves and particles. In the present paper we propose a new way of considering the problem, firstly by showing the existence of a new property of quantum waves, the production of correlations at a distance in a way surprisingly reminiscent of EPR states, and secondly by stressing how the presence of such wave-like correlations is incompatible with the determination of the path followed by the particles.
We believe that our proposed experiment may support a realistic interpretation of the wave-particle duality, since both wave-like and particle-like aspects give rise to different and complementary predictions
On the Physical Reality of Quantum Waves
No full textThe main interpretations of the quantum-mechanical wave function are presented emphasizing how they can be divided into two ensembles: The ones that deny and the other ones that attribute a form of reality to quantum waves.
It is also shown why these waves cannot be classical and must be submitted to the restriction of the complementarity principle. Applying the concept of smooth complementarity, it is shown that there can be no reason to attribute reality only to the events and not to the wave or to the initial state of a given system.
Thereafter, an experiment proposed by the authors is presented, where it is shown that the wave-like behaviour allows predictions that are not allowed on the grounds of a particle-like behaviour. In conclusion, we upheld that quantum waves must be real even if they do not belong to the same ontological level of events, which connected with particle detections
Damage Detection and Localization on Real Structures Subjected to Strong Motion Earthquakes Using the Curvature Evolution Method: The Navelli (Italy) Case Study
Full text linkIn recent years, structural health monitoring (SHM) has received increasing interest from both research and professional engineering communities. This is due to the limitations related to the use of traditional methods based on visual inspection for a rapid and effective assessment of structures and infrastructures when compared with the great potential offered by newly developed automatic systems. Most of these kinds of systems allow the continuous estimation of structural modal properties that are strictly correlated to the mechanical characteristics of the monitored structure. These can change as a result of material deterioration and structural damage related to earthquake shaking. Furthermore, a suitable configuration of a dense sensor network in a real-time monitoring system can allow to detect and localize structural and non-structural damage by comparing the initial and a final state of the structure after a critical event, such as a relevant earthquake. In this paper, the modal curvature evaluation method, used for damage detection and localization on framed structures, considering the mode curvature variation due to strong earthquake shaking, is further developed. The modified approach is validated by numerical and experimental case studies. The extended procedure, named "Curvature Evolution Method" (CEM), reduces the required computing time and the uncertainties in the results. Furthermore, in this work, an empirical relationship between curvature variation and damage index has been defined for both bare and infilled frames
Enlarged vestibular aqueduct and Mondini Malformation: audiological, clinical, radiologic and genetic features
Full text linkPurpose: When referring to enlarged vestibular aqueduct (EVA) we should differentiate between nonsyndromic enlarged vestibular aqueduct (NSEVA) and Pendred Syndrome (PDS), a disease continuum associated with pathogenic sequence variants of Pendrin’s Gene (SLC26A4) in about half of the cases. The study was aimed to analyse the clinical and audiological features of a monocentric cohort of Caucasian patients with NSEVA/PDS, their genetic assessment and morphological inner ear features. Methods: We retrospectively reviewed the audiologic, genetic and anamnestic data of 66 patients with NSEVA/PDS followed by our audiology service. Results: SLC26A4 mutations was significantly correlated with the presence of PDS rather than NSEVA (p < 0.019), with the expression of inner ear malformations (p < 0.001) and with different severity of hearing loss (p = 0.001). Furthermore, patients with PDS showed significantly worse pure tone audiometry (PTA) than patients with NSEVA (p = 0.001). Anatomically normal ears presented significantly better PTA than ears associated with Mondini Malformation or isolated EVA (p < 0.001), but no statistically significative differences have been observed in PTA between patients with Mondini Malformation and isolated EVA. Conclusion: NSEVA/PDS must be investigated in all the congenital hearing loss, but also in progressive, late onset, stepwise forms. Even mixed or fluctuating hearing loss may constitute a sign of a NSEVA/PDS pathology. Our findings can confirm the important role of SLC26A4 mutations in determining the phenotype of isolated EVA/PDS, both for the type/degree of the malformation, the hearing impairment and the association with thyroid dysfunction
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