Speckle pattern formation in spatially limited optical systems

The dependences of statistical parameters inherent to speckle patterns on the object roughness and aperture size have been investigated. The experimental results that confirm theoretical dependence quality within the limits of errors were obtained. It has been shown that spatial finiteness of the optical system causes significant changes of transferred field

Determination of surface defects by using the wavefront scanner

The possibility of changes in the polarization state of the laser beam reflected from inhomogeneity with the refractive index gradient is theoretically shown, which allows separating the phase shifts related with relief inhomogeneities and local changes of the surface refractive index. Modification of the wavefront scanner for analyzing the wavefront of the laser beam reflected from the samples’ surface is considered. The main idea of the method is to use the focused laser beams with different polarizations for illuminating separate areas of the surface. The results of detecting test surfaces with different structures by the wavefront scanner are presented

The structure of interstitial lung diseases in children of the first two years of life

For the first time in Russia, the article provides data on interstitial lung diseases structure in children of the first two years of life, based on a series of observations of 68 patients with these rare diseases, as a part of multi-center ambispective study. Interstitial lung diseases in observed children included: Wilson-Mikity syndrome (23,4%), neuroendocrine hyperplasia of infancy (22%), bronchiolitis obliterans with organizing pneumonia (7,4%), primary pulmonary hypoplasia (1,5%), secondary pulmonary hypoplasia with Jeune syndrome (10,3%), secondary pulmonary hypoplasia with Edwards syndrome (2,9%), secondary pulmonary hypoplasia with other associated pathology (omphalocele - 1,5%, non-immune fetal hydrops - 1,5%), subpleural cysts in patients with Down syndrome (5,9%), congenital deficiency of surfactant protein B (1,5%), brain-lung- thyroid syndrome (2,9%), congenital alveolar-capillary dysplasia (1,5%), interstitial lung diseases with systemic diseases (Langerhans cell histiocytosis - 16,2%, Niemann-Pick disease - 1,5%). The article summarizes clinical features, the results of image diagnosis and disease outcomes. © 2015, Pediatria Ltd. All rights reserved

The structure of interstitial lung diseases in children of the first two years of life

For the first time in Russia, the article provides data on interstitial lung diseases structure in children of the first two years of life, based on a series of observations of 68 patients with these rare diseases, as a part of multi-center ambispective study. Interstitial lung diseases in observed children included: Wilson-Mikity syndrome (23,4%), neuroendocrine hyperplasia of infancy (22%), bronchiolitis obliterans with organizing pneumonia (7,4%), primary pulmonary hypoplasia (1,5%), secondary pulmonary hypoplasia with Jeune syndrome (10,3%), secondary pulmonary hypoplasia with Edwards syndrome (2,9%), secondary pulmonary hypoplasia with other associated pathology (omphalocele - 1,5%, non-immune fetal hydrops - 1,5%), subpleural cysts in patients with Down syndrome (5,9%), congenital deficiency of surfactant protein B (1,5%), brain-lung- thyroid syndrome (2,9%), congenital alveolar-capillary dysplasia (1,5%), interstitial lung diseases with systemic diseases (Langerhans cell histiocytosis - 16,2%, Niemann-Pick disease - 1,5%). The article summarizes clinical features, the results of image diagnosis and disease outcomes. © 2015, Pediatria Ltd. All rights reserved

Disruption prediction with artificial intelligence techniques in tokamak plasmas

In nuclear fusion reactors, plasmas are heated to very high temperatures of more than 100 million kelvin and, in so-called tokamaks, they are confined by magnetic fields in the shape of a torus. Light nuclei, such as deuterium and tritium, undergo a fusion reaction that releases energy, making fusion a promising option for a sustainable and clean energy source. Tokamak plasmas, however, are prone to disruptions as a result of a sudden collapse of the system terminating the fusion reactions. As disruptions lead to an abrupt loss of confinement, they can cause irreversible damage to present-day fusion devices and are expected to have a more devastating effect in future devices. Disruptions expected in the next-generation tokamak, ITER, for example, could cause electromagnetic forces larger than the weight of an Airbus A380. Furthermore, the thermal loads in such an event could exceed the melting threshold of the most resistant state-of-the-art materials by more than an order of magnitude. To prevent disruptions or at least mitigate their detrimental effects, empirical models obtained with artificial intelligence methods, of which an overview is given here, are commonly employed to predict their occurrence—and ideally give enough time to introduce counteracting measures

Enhanced performance in fusion plasmas through turbulence suppression by megaelectronvolt ions

© 2022, The Author(s), under exclusive licence to Springer Nature Limited.Alpha particles with energies on the order of megaelectronvolts will be the main source of plasma heating in future magnetic confinement fusion reactors. Instead of heating fuel ions, most of the energy of alpha particles is transferred to electrons in the plasma. Furthermore, alpha particles can also excite Alfvénic instabilities, which were previously considered to be detrimental to the performance of the fusion device. Here we report improved thermal ion confinement in the presence of megaelectronvolts ions and strong fast ion-driven Alfvénic instabilities in recent experiments on the Joint European Torus. Detailed transport analysis of these experiments reveals turbulence suppression through a complex multi-scale mechanism that generates large-scale zonal flows. This holds promise for more economical operation of fusion reactors with dominant alpha particle heating and ultimately cheaper fusion electricity.N