5,227 research outputs found

    Radio-frequency Bloch-transistor electrometer

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    A quantum-limited electrometer based on charge modulation of the Josephson supercurrent in the Bloch transistor inserted into a superconducting ring is proposed. As this ring is inductive coupled to a high-Q resonance tank circuit, the variations of the charge on the transistor island (input signal) are converted into variations of amplitude and phase of radio-frequency oscillations in the tank. These variations are amplified and then detected. The output noise, the back-action fluctuations and their cross-correlation are computed. It is shown that our device enables measurements of the charge with a sensitivity which is determined by the energy resolution of its amplifier, that can be reduced down to the standard quantum limit of \hbar/2. On the basis of this setup a "back-action-evading" scheme of the charge measurements is proposed.Comment: 5 pages incl. 2 figure

    Modeling of electricity consumption in the systems with smart equipment

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    Big data is the foundation of modern energy management systems. There are two energy consumption models where systems are one of the consumers with intelligent equipment: static and dynamic. The dynamic model uses a two-tariff closed-loop accounting scheme, which implies changes in tariffs based on the analysis of current consumption. The results of an experimental study of both models using energy consumption data are presented. The influence of the number of such devices on the possibility of achieving uniform consumption when using the second model is shown. Usage of machine learning for generation a consumption forecast based on time series is show

    Laser Stripping for the PS2 Charge-Exchange Injection System

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    Laser stripping for an H- injection system into the proposed PS2 accelerator could provide an attractive alternative to the use of a conventional stripping foil. In this paper possible concepts for a 4 GeV laser stripping system are outlined and compared, using either laser or magnetic initial stripping steps and a resonant excitation of the intermediate H0 atom, followed by a final magnetic stripping. Issues of laser power, overall efficiency and emittance growth are discussed

    Parity nonconservation effects in the photodesintegration of polarized deuterons

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    P-odd correlations in the deuteron photodesintegration are considered. The π\pi-meson exchange is not operative in the case of unpolarized deuterons. For polarized deuterons a P-odd correlation due to the π\pi-meson exchange is about 3×1093 \times 10^{-9}. Short-distance P-odd contributions exceed essentially than the contribution of the π\pi-meson exchange.Comment: 12 pages, Latex, 3 figure

    Resonance Absorption of Light By Subwavelength Diffractive Gratings

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    Diffraction of light of a visible spectral range by subwavelength metal gratings is investigated theoretically and experimentally. The influence of different grating parameters (filling factor, shape and depth, material, angle of incidence, wavelength and polarization of radiation) on diffraction efficiency is investigated. The conditions are found under which there are only zero diffraction order and the minus first order. It is established that the zero order can be suppressed by selecting the depth and shape of the grating relief. High diffraction efficiency in the -1st order is observed with increasing depth of the grating relief (more than 70% at a depth h = 80 nm). It is shown that under certain conditions an effect of plasmon resonance occurs, at which there is a complete absorption of the incident radiation. The considered optical elements can be used in systems for image processing, projection displays, in the development of a variety of sensors, etc. Keywords: subwavelength grating, diffraction efficiency, plasmon resonanc

    The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

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    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications

    NEW DATA ON AGE AND NATURE OF CARBONIZATION WITHIN SOUTHERN FLANK OF THE BAIKAL LEDGE OF THE SIBERIAN CRATON BASEMENT

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    The Baikal ledge rock formations in the Siberian craton structure are included in the Akitkan mobile belt which is considered as the Late Paleoproterozoic independent island arc system moved up to the ancient basement during the terrains amalgamation 1.91–2.00 Ga ago (Fig. 1) [Rosen, 2003; Gladkochub et al., 2009; Didenko et al., 2013].The Baikal ledge rock formations in the Siberian craton structure are included in the Akitkan mobile belt which is considered as the Late Paleoproterozoic independent island arc system moved up to the ancient basement during the terrains amalgamation 1.91–2.00 Ga ago (Fig. 1) [Rosen, 2003; Gladkochub et al., 2009; Didenko et al., 2013]

    Segmentation of anatomical structures of the heart based on echocardiography

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    Nowadays, many practical applications in the field of medical image processing require valid and reliable segmentation of images in the capacity of input data. Some of the commonly used imaging techniques are ultrasound, CT, and MRI. However, the main difference between the other medical imaging equipment and EchoCG is that it is safer, low cost, non-invasive and non-traumatic. Three-dimensional EchoCG is a non-invasive imaging modality that is complementary and supplementary to two-dimensional imaging and can be used to examine the cardiovascular function and anatomy in different medical settings. The challenging problems, presented by EchoCG image processing, such as speckle phenomena, noise, temporary non-stationarity of processes, unsharp boundaries, attenuation, etc. forced us to consider and compare existing methods and then to develop an innovative approach that can tackle the problems connected with clinical applications. Actual studies are related to the analysis and development of a cardiac parameters automatic detection system by EchoCG that will provide new data on the dynamics of changes in cardiac parameters and improve the accuracy and reliability of the diagnosis. Research study in image segmentation has highlighted the capabilities of image-based methods for medical applications. The focus of the research is both theoretical and practical aspects of the application of the methods. Some of the segmentation approaches can be interesting for the imaging and medical community. Performance evaluation is carried out by comparing the borders, obtained from the considered methods to those manually prescribed by a medical specialist. Promising results demonstrate the possibilities and the limitations of each technique for image segmentation problems. The developed approach allows: to eliminate errors in calculating the geometric parameters of the heart; perform the necessary conditions, such as speed, accuracy, reliability; build a master model that will be an indispensable assistant for operations on a beating heart
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