1,081 research outputs found

    Exploring GLIMPSE Bubble N107: Multiwavelength Observations and Simulations

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    Context. Bubble N107 was discovered in the infrared emission of dust in the Galactic Plane observed by the Spitzer Space Telescope (GLIMPSE survey: l ~ 51.0 deg, b ~ 0.1 deg). The bubble represents an example of shell-like structures found all over the Milky Way Galaxy. Aims. We aim to analyse the atomic and molecular components of N107, as well as its radio continuum emission. With the help of numerical simulations, we aim to estimate the bubble age and other parameters which cannot be derived directly from observations. Methods. From the observations of the HI (I-GALFA) and 13CO (GRS) lines we derive the bubble's kinematical distance and masses of the atomic and molecular components. With the algorithm DENDROFIND, we decompose molecular material into individual clumps. From the continuum observations at 1420 MHz (VGPS) and 327 MHz (WSRT), we derive the radio flux density and the spectral index. With the numerical code ring, we simulate the evolution of stellar-blown bubbles similar to N107. Results. The total HI mass associated with N107 is 5.4E3 Msun. The total mass of the molecular component (a mixture of cold gasses of H2, CO, He and heavier elements) is 1.3E5 Msun, from which 4.0E4 Msun is found along the bubble border. We identified 49 molecular clumps distributed along the bubble border, with the slope of the clump mass function of -1.1. The spectral index of -0.30 of a strong radio source located apparently within the bubble indicates nonthermal emission, hence part of the flux likely originates in a supernova remnant, not yet catalogued. The numerical simulations suggest N107 is likely less than 2.25 Myr old. Since first supernovae explode only after 3 Myr or later, no supernova remnant should be present within the bubble. It may be explained if there is a supernova remnant in the direction towards the bubble, however not associated with it.Comment: 15 pages, 11 figure

    THE MEANS OF SPECIAL ORIENTATION OF CHILDREN WITH VISUAL IMPAIRMENTS IN FAMILY EDUCATION CONDITIONS

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    In the article the main directions, theoretical-practical ways of development of spatial orientation of preschool children with visual development, and its necessity in family education conditions are presented. The aim of the research is to elaborate means, methods and conditions of their application for development of the ability of the spatial orientation of preschool children with visual impairments in family settings. To provide parents with visual knowledge is the result of implemented works.In the article the main directions, theoretical-practical ways of development of spatial orientation of preschool children with visual development, and its necessity in family education conditions are presented. The aim of the research is to elaborate means, methods and conditions of their application for development of the ability of the spatial orientation of preschool children with visual impairments in family settings. To provide parents with visual knowledge is the result of implemented works

    Multi-branch Convolutional Neural Network for Multiple Sclerosis Lesion Segmentation

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    In this paper, we present an automated approach for segmenting multiple sclerosis (MS) lesions from multi-modal brain magnetic resonance images. Our method is based on a deep end-to-end 2D convolutional neural network (CNN) for slice-based segmentation of 3D volumetric data. The proposed CNN includes a multi-branch downsampling path, which enables the network to encode information from multiple modalities separately. Multi-scale feature fusion blocks are proposed to combine feature maps from different modalities at different stages of the network. Then, multi-scale feature upsampling blocks are introduced to upsize combined feature maps to leverage information from lesion shape and location. We trained and tested the proposed model using orthogonal plane orientations of each 3D modality to exploit the contextual information in all directions. The proposed pipeline is evaluated on two different datasets: a private dataset including 37 MS patients and a publicly available dataset known as the ISBI 2015 longitudinal MS lesion segmentation challenge dataset, consisting of 14 MS patients. Considering the ISBI challenge, at the time of submission, our method was amongst the top performing solutions. On the private dataset, using the same array of performance metrics as in the ISBI challenge, the proposed approach shows high improvements in MS lesion segmentation compared with other publicly available tools.Comment: This paper has been accepted for publication in NeuroImag

    Description of nuclear octupole and quadrupole deformation close to the axial symmetry: Octupole vibrations in the X(5) nuclei 150Nd and 152Sm

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    The model, introduced in a previous paper, for the description of the octupole and quadrupole degrees of freedom in conditions close to the axial symmetry, is used to describe the negative-parity band based on the first octupole vibrational state in nuclei close to the critical point of the U(5) to SU(3) phase transition. The situation of 150Nd and 152Sm is discussed in detail. The positive parity levels of these nuclei, and also the in-band E2 transitions, are reasonably accounted for by the X(5) model. With simple assumptions on the nature of the octupole vibrations, it is possible to describe, with comparable accuracy, also the negative parity sector, without changing the description of the positive-parity part.Comment: 8 pages, 5 figure

    Analisa Kinerja Pneumatic Wave Energy Converter (WEC) Dengan Menggunakan Oscillating Water Column(OWC)

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    Sistem konversi energi gelombang laut merupakan sistem yang menangkap energi gelombang laut untuk dikonversi menjadi energi lain seperti energi listrik. Salah satu jenis wave energy converter (WEC) yang banyak digunakan diantaranya yaitu Oscillating Water Columnatau OWC. Prinsip kerja sistem WEC ini ialah mengubah pergerakan naik turunnya gelombang pada silinder kolom udara untuk menghasilkan udara bertekanan yang selanjutnya digunakan untuk menggerakkan turbin dan generator listrik. Penelitian ini ditujukan untuk dapat mengetahui kinerja dari Oscillating Water Column (OWC) dalam menangkap energi gelombang laut. Untuk dapat melakukan penelitian ini diperlukan beberapa perlatan yaitu pembuatan konfigurasi peralatan pembuat dan penangkapan gelombang yang terdiri dari pelampung dan silinder Oscillating Water Column (OWC). Percobaan ini dilakukan dengan cara memvariasikan panjang dan tinggi gelombang pada flow water channel dengan mengatur bukaan pada pneumatic speed control. Dari hasil percobaan diperoleh bahwa kinerja paling efektif diperoleh pada panjang gelombang 0.9 m dan tinggi gelombang 0.23m. Pada karakteristik gelombang tersebut diperoleh tekanan, kecepatan dan volume pada silinder Oscillating Water Column (OWC) sebesar 1.11 bar, 39.39 m/s dan 0.0057 m3. Dari hasil percobaan juga diperoleh waktu pengisian Pressure Vessel selama 100 menit dengan tekanan 3 Psi

    Description of nuclear octupole and quadrupole deformation close to the axial symmetry and phase transitions in the octupole mode

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    The dynamics of nuclear collective motion is investigated in the case of reflection-asymmetric shapes. The model is based on a new parameterization of the octupole and quadrupole degrees of freedom, valid for nuclei close to the axial symmetry. Amplitudes of oscillation in other degrees of freedom different from the axial ones are assumed to be small, but not frozen to zero. The case of nuclei which already possess a permanent quadrupole deformation is discussed in some more detail and a simple solution is obtained at the critical point of the phase transition between harmonic octupole oscillation and a permanent asymmetric shape. The results are compared with experimental data of the Thorium isotopic chain. The isotope Th-226 is found to be close to the critical point.Comment: 17 pages, 5 figures, 8 tables; 3 new references added, misprints correcte
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