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 "Dhar, A." wg kryterium: Autor

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-6 z 6
    Tytuł:
    Effect of capillarity on fourth order nonlinear evolution equation for two Stokes wave trains in deep water in the presence of air flowing over water
    Autorzy:
    Dhar, A. K.
    Mondal, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/265884.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    nonlinear evolution equation
    surface capillary gravity wave
    stability
    grawitacja
    fala kapilarna
    równania nieliniowe
    Opis:
    Fourth order nonlinear evolution equations, which are a good starting point for the study of nonlinear water waves, are derived for deep water surface capillary gravity waves in the presence of second waves in which air is blowing over water. Here it is assumed that the space variation of the amplitude takes place only in a direction along which the group velocity projection of the two waves overlap. A stability analysis is made for a uniform wave train in the presence of a second wave train. Graphs are plotted for the maximum growth rate of instability wave number at marginal stability and wave number separation of fastest growing sideband component against wave steepness. Significant improvements are noticed from the results obtained from the two coupled third order nonlinear Schrödinger equations.
    Źródło:
    International Journal of Applied Mechanics and Engineering; 2015, 20, 2; 267-282
    1734-4492
    2353-9003
    Pojawia się w:
    International Journal of Applied Mechanics and Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modulational instability of obliquely interacting capillary-gravity waves over infinite depth
    Autorzy:
    Manna, S.
    Dhar, A. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/38629088.pdf
    Data publikacji:
    2021
    Wydawca:
    Instytut Podstawowych Problemów Techniki PAN
    Tematy:
    nonlinear Schrödinger equation
    crossing sea states
    capillary-gravity waves
    modulational instability
    Opis:
    Two coupled time-dependent two dimensional nonlinear Schrödinger equations have been derived using multiscale expansion for two nonlinearly interacting capillary-gravity waves over an infinite depth of water. These equations are then utilised to discuss the modulational (Benjamin-Feir) instability of two Stokes wavetrains due to unidirectional and bidirectional perturbations. It is found from the graphs and the three-dimensional contour plots that the rate of growth of instability for two wave packets interacting obliquely is higher than the instance of modulation of one wave packet. We have likewise examined the influence of capillarity on modulational instability.
    Źródło:
    Archives of Mechanics; 2021, 73, 5-6; 583-598
    0373-2029
    Pojawia się w:
    Archives of Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fourth order nonlinear evolution equation for interfacial gravity waves in the presence of air flowing over water and a basic current shear
    Autorzy:
    Majumder, D. P.
    Dhar, A. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/265668.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    nonlinear evolution equation
    basic current shear
    Stokes gravity wave
    równania nieliniowe
    przepływy Stokes'a
    grawitacja
    Opis:
    A fourth order nonlinear evolution equation, which is a good starting point for the study of nonlinear water waves as first pointed out by Dysthe (1979) is derived for gravity waves propagating at the interface of two superposed fluids of infinite depth in the presence of air flowing over water and a basic current shear. A stability analysis is then made for a uniform Stokes gravity wave train. Graphs are plotted for the maximum growth rate of instability and for wave number at marginal stability against wave steepness for different values of air flow velocity and basic current shears. Significant deviations are noticed from the results obtained from the third order evolution equation, which is the nonlinear Schrödinger equation.
    Źródło:
    International Journal of Applied Mechanics and Engineering; 2015, 20, 3; 517-530
    1734-4492
    2353-9003
    Pojawia się w:
    International Journal of Applied Mechanics and Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of randomness on the stability of capillary gravity waves in the presence of air flowing over water
    Autorzy:
    Majumder, D. P.
    Dhar, A. K.
    Powiązania:
    https://bibliotekanauki.pl/articles/265777.pdf
    Data publikacji:
    2015
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    capillary gravity waves
    randomness
    evolution equation
    instability
    fala grawitacyjna
    przypadkowość
    niestabilność
    Opis:
    A nonlinear spectral transport equation for the narrow band Gaussian random surface wave trains is derived from a fourth order nonlinear evolution equation, which is a good starting point for the study of nonlinear water waves. The effect of randomness on the stability of deep water capillary gravity waves in the presence of air flowing over water is investigated. The stability is then considered for an initial homogenous wave spectrum having a simple normal form to small oblique long wave length perturbations for a range of spectral widths. An expression for the growth rate of instability is obtained; in which a higher order contribution comes from the fourth order term in the evolution equation, which is responsible for wave induced mean flow. This higher order contribution produces a decrease in the growth rate. The growth rate of instability is found to decrease with the increase of spectral width and the instability disappears if the spectral width increases beyond a certain critical value, which is not influenced by the fourth order term in the evolution equation.
    Źródło:
    International Journal of Applied Mechanics and Engineering; 2015, 20, 4; 835-855
    1734-4492
    2353-9003
    Pojawia się w:
    International Journal of Applied Mechanics and Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stand structure and natural regeneration of Taxus baccata at "Stiwollgraben" in Austria
    Autorzy:
    Dhar, A
    Ruprecht, H.
    Klumpp, R.
    Vacik, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/41025.pdf
    Data publikacji:
    2006
    Wydawca:
    Polska Akademia Nauk. Instytut Dendrologii PAN
    Tematy:
    English yew
    Taxus baccata
    yew
    tree species
    Austria
    gene conservation
    natural regeneration forest
    stand structure
    population structure
    vitality
    yew decline
    Opis:
    English yew (Taxus baccata L.) is a rare tree species in Austria and gene conservation forests reserves are used to maintain English yew populations by silvicultural treatments. This paper describes the current situation of an English yew population at “Stiwollgraben”in Austria with regard to stand structure, vitality and natural regeneration. The area is one of the most important sites in Austria as it consists of 2236 yews.The vitality condition of the yew is very good, and more than 79% of the yews have been assessed as very vital to vital. The potentiality for natural regeneration (13019 one-year seedlings ha–1) is very high, but not all height classes are represented. This indicates a high survival ability of English yew at this site. Three different treatment strategies are described to maintain the yew population. The future effects of these treatments are discussed in the light of the environmental requirements of English yew.
    Źródło:
    Dendrobiology; 2006, 56; 19-26
    1641-1307
    Pojawia się w:
    Dendrobiology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Erbium and Al2O3 nanocrystals-doped silica optical fibers
    Autorzy:
    Kasik, I.
    Podrazky, O.
    Mrazek, J.
    Cajzl, J.
    Aubrecht, J.
    Probostova, J.
    Peterka, P.
    Honzatko, P.
    Dhar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/201901.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    włókna optyczne
    nanokryształy
    doping ziem rzadkich
    luminescencja
    optical fibers
    nanocrystals
    rare-earth doping
    luminescence
    Opis:
    Fibre lasers and inherently rare-earth-doped optical fibers nowadays pass through a new period of their progress aiming at high efficiency of systems and their high power. In this paper, we deal with the preparation of silica fibers doped with erbium and Al2O3 nanocrystals and the characterization of their optical properties. The fibers were prepared by the extended Modified Chemical Vapor Deposition (MCVD) method from starting chlorides or oxide nanopowders. Conventional as well as modified approaches led to a nanocrystalline mullite phase formation in the fiber cores in which erbium is dissolved. The proposed modified approach based on starting nanopowders led to improved geometry of preforms and fibers and consequently to the improvement of their background attenuation. Such nanocrystal -doped fibers can be used for ASE sources. Further improvement of fiber optical properties can be expected.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 4; 641-646
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-6 z 6

      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