Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "channels" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-8 z 8
    Tytuł:
    Modeling the phenomena accompanying the condensation of environmentally friendly refrigerants in mini-channels
    Autorzy:
    Kuczyński, Waldemar
    Powiązania:
    https://bibliotekanauki.pl/articles/2204074.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    refrigerants
    condensation
    mini-channels
    Opis:
    This paper presents the results of an experimental study and mathematical modeling of the effect of dynamic instabilities on the condensation phase transformation of the refrigerants homogeneous R134a and its replacement in the form of isomers R1234yf and R1234ze and R404A or R507 and R448A in pipe mini-channels. In the case of homogeneous chlorofluorocarbons (CFCs), it is the 1234 isomers that are envisioned as substitutes for the withdrawn ones with high ozone depletion potential and global warming potential. For zeotropic and azeotropic mixtures, for example, these are R507 or R448A. The paper presents a dimensional analysis procedure based on the Buckingham Π theorem to develop a regression velocity model of pressure dynamic instabilities. The experimental part of the work was carried out with the use of tubular mini-channels with internal diameter 1.40–3.3 mm.
    Źródło:
    Archives of Thermodynamics; 2023, 44, 1; 121--137
    1231-0956
    2083-6023
    Pojawia się w:
    Archives of Thermodynamics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On a New Approach to SNR Estimation of BPSK Signals
    Autorzy:
    Moazzeni, T.
    Amei, A.
    Ma, J.
    Jiang, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/227148.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    digital communication
    statistical analysis
    AWGN channels
    Opis:
    Signal-to-noise ratio (SNR) information is required in many communication receivers and their proper operation is, to a large extent, related to the SNR estimation techniques they employ. Most of the available SNR estimators are based on approaches that either require large observation length or suffer from high computation complexity. In this paper, we propose a low complexity, yet accurate SNR estimation technique that is sufficient to yield meaningful estimation for short data records. It is shown that our estimator is fairly close to the (CRLB) for high SNR values. Numerical results also confirm that, in terms of convergence speed, the proposed technique outperforms the popular moment based method, M2M4.
    Źródło:
    International Journal of Electronics and Telecommunications; 2012, 58, 3; 273-278
    2300-1933
    Pojawia się w:
    International Journal of Electronics and Telecommunications
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Power Allocation for Energy-Harvesting-based Fading Cognitive Multiple Access Channels : with or without Successive Interference Cancellation
    Autorzy:
    Li, Q.
    Xu, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/963855.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    cognitive radio
    power allocation
    multiple access channels
    energy harvesting
    Opis:
    This paper considers a fading cognitive multiple access channel (CMAC), where multiple secondary users (SUs), who share the spectrum with a primary user (PU), transmit to a cognitive base station (CBS). A power station is assumed to harvest energy from the nature and then provide power to the SUs. We investigate the power allocation problems for such a CMAC to maximize the SU sum rate under the interference power constraint, the sum transmit power constraint and the peak transmit power constraint of each individual SU. In particular, two scenarios are considered: with successive interference cancellation (SIC) and without SIC. For the first scenario, the optimal power allocation algorithm is derived. For the second scenario, a heuristic algorithm is proposed. We show that the proposed algorithm with SIC outperforms the algorithm without SIC in terms of the SU sum rate, while the algorithm without SIC outperforms the algorithm with SIC in terms of the number of admitted SUs for a high sum transmit power limit and a low peak transmit power limit of each individual SU.
    Źródło:
    International Journal of Electronics and Telecommunications; 2017, 63, 1; 65-72
    2300-1933
    Pojawia się w:
    International Journal of Electronics and Telecommunications
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Shaping of Panel Materials in Light Direction Design
    Autorzy:
    Urzędowski, A.
    Wójcicka-Migasiuk, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/354766.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    reflective materials
    illumination channels
    surface shaping
    reflection
    non-imaging optics
    Opis:
    Abstract The paper presents the methodology of the analysis of the materials used in solar energy conversion, and an elaborated example with simulations of obtained results. Material properties are selected in relation to the need of sunlight illumination applications in civil constructions. This process is presented , starting from the analysis of some aspects of solar radiation, through the calculations of lens curvature and leading to the execution of simulations in different conditions. Graphical presentation of the phenomenon, it can visualize the process of shaping curves. The materials such as glass, polymers, metals, and gases have been discussed. Particular attention was paid to the results of the transmission of materials, their reflection and absorption of solar radiation. Moreover, the research problems of illumination and reflection in multi-layer structures used for civil constructions have been presented.
    Źródło:
    Archives of Metallurgy and Materials; 2016, 61, 2B; 941-945
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of the possibilities of using composite structural c-channels as lining for an arch support in mining excavation
    Autorzy:
    Rotkegel, Marek
    Korol, Jerzy
    Sobczak, Dagmara
    Powiązania:
    https://bibliotekanauki.pl/articles/2073872.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    wyrobisko chodnikowe
    profil konstrukcyjny
    bezpieczeństwo górnicze
    górnicza obudowa powłokowa
    research
    lining
    arch support
    composite c-channels
    Opis:
    The article is the result of a project aimed at developing and implementing a design of composite accessories for support in excavations located in underground hard coal mines. The research team verified the possibility of using elements made of prefabricated composite structural profile as an alternative to steel and reinforced concrete lining elements used to improve support’s stability and protect against rockfall. This paper includes a research experiment on the possibilities of using a composite C-profile element as lining made in the pultrusion technology with a longitudinal position of the roving. The prefabricated structural profiles were adapted to the function by designing seatings for fitting the flanges for arch support’s V-profiles. Prototypes of these elements were subjected to bench tests in compliance with the guidelines for testing mesh linings. In addition, computer simulations using the finite element method were carried out. The values obtained during the tests were compared with the requirements for lightweight mesh and included the Polish standard PN-G-15050 and reinforced A-type concrete lining defined in the standard PN-G-06021. The team determined the areas where material strength exceeded and the structure was damaged. Despite the limited quantity of laboratory tests and lack of field tests in actual mining conditions, it was possible to address the argument of the research and determine whether it is possible to use C-profile made in the pultrusion technology as a lining element.
    Źródło:
    Archives of Mining Sciences; 2021, 66, 3; 437--455
    0860-7001
    Pojawia się w:
    Archives of Mining Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Inverse Problem for Looped River Networks – Lower Oder River Case Study
    Autorzy:
    Kurnatowski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/204959.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    kanały otwarte
    sieci zapętlone
    współczynnik chropowatości
    Odra
    open channels
    looped networks
    inverse problem
    roughness coefficient
    lower Oder river
    Opis:
    Identification of coefficients determining flow resistance, in particular Manning’s roughness coefficients, is one of the possible inverse problems of mathematical modeling of flow distribution in looped river networks. The paper presents the solution of this problem for the lower Oder River network consisting of 78 branches connected by 62 nodes. Using results of six sets of flow measurements at particular network branches it was demonstrated that the application of iterative algorithm for roughness coeffi cients identification on the basis of the sensitivity-equation method leads to the explicit solution for all network branches, independent from initial values of identifi ed coefficients.
    Źródło:
    Archives of Environmental Protection; 2013, 39, 1; 105-118
    2083-4772
    2083-4810
    Pojawia się w:
    Archives of Environmental Protection
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Facies anatomy of a progradational submarine channelized lobe complex: semi-quantitative analysis of the Ropianka Formation (Campanian-Paleocene) in Hucisko Jawornickie section, Skole Nappe, Polish Carpathians
    Autorzy:
    Łapcik, Piotr
    Powiązania:
    https://bibliotekanauki.pl/articles/138693.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    deep-marine turbidites
    depositional lobes
    submarine channels
    dynamic stratigraphy
    facies analysis
    Markov chain analysis
    turbidyty
    loby depozycyjne
    kanały podmorskie
    stratygrafia dynamiczna
    analiza facjalna
    łańcuch Markova
    Opis:
    This study is a detailed lithofacies analysis of the Wiar and Leszczyny members of the deep-marine Ropianka Formation (Campanian–Paleocene) exposed in the Hucisko Jawornickie section of the Skole Nappe, Polish Carpathian Flysch. The sedimentary succession (>400 m thick) represents a channelized lobe complex that prograded at the base of submarine slope. Seven sedimentary facies are recognized as a record of the principal modes of sediment deposition. Based on their stratigraphic grouping and grain-size trends, six facies associations are distinguished as representing specific sub-environments of the depositional system: distributary channels, channel-mouth lobes, channel levees, crevasses and interlobe basin plain with crevasse splays. The individual facies associations are characterized statistically and their internal facies organization is analysed by the method of embedded Markov chains to reveal the time pattern of depositional processes. The environmental changes indicated by the vertical succession of facies associations are attributed to the autogenic processes of the distributary channel shifting within an aggrading lobe area and the lateral switching of depositional lobes. Eustatic influences are likely, but difficult to ascertain with poor biostratigraphic data. The bulk basinward advance of the base-of-slope system was probably due to a pulse of the tectonic narrowing of the synclinal Skole Basin.
    Źródło:
    Acta Geologica Polonica; 2019, 69, 1; 111-141
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fusion reaction study of halo system by quantum mechanical-based model for ⁶He+⁶⁴Zn, ⁸B+⁵⁸Ni and 8He+¹⁹⁷Au systems
    Autorzy:
    Abd Madhi, Maryam H.
    Majeed, Fouad A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2086832.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    semi-classical treatment
    fusion barrier distribution
    halo nuclei
    fusion cross-section
    continuum discretized coupled channels
    półklasyczne działanie
    dystrybucja bariery termojądrowej
    jądro halo
    przekrój fuzji
    kanał sprzężony
    Opis:
    In the current work the calculations of the reaction cross-section of total fusion σ fus, the fusion barrier distribution D fus, and the probability P fus were achieved for systems ⁶He+⁶⁴Zn, ⁸B+⁵⁸Ni and ⁸He+¹⁹⁷Au which involve halo nuclei by using a semiclassical approach. The semiclassical and quantum mechanics treatments comprise the approximation of WKB for describing the relative motion among projectile nuclei and target nuclei, and the method of CDCC (Continuum Discretized Coupled Channel) for describing the intrinsic motion for the projectile and target nuclei. Our semiclassical calculations yielded findings that were compared to obtainable experimental data as well as quantum mechanics calculations. For fusion cross-sections σ fus below and above the Coulomb barrier Vb, the quantum mechanics coupled channels are very similar, according to the experimental results.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 4; e137734, 1--6
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies