Results 251 to 260 of about 409,759 (297)

Intrinsic nonaxisymmetric instabilities in galaxy rings

New Astronomy, 1997
Abstract We have investigated numerically the stability and temporal evolution of two-dimensional self-gravitating galaxy rings with flat rotation curves. The initial equilibrium models are composed of a polytropic fluid characterized by various polytropic indices (n = 0.5, 1, 1.5, 3, and 5) and embedded in a rigid scale-free logarithmic potential ...
Dimitris M. Christodoulou, John E. Cazes, Joel E. Tohline   +2 more
openaire   +1 more source

Intrinsic thermoacoustic instability of premixed flames

Combustion and Flame, 2015
Abstract The thermoacoustic stability of velocity sensitive premixed flames is investigated. A causal representation of the flow-flame-acoustic interactions reveals a flame-intrinsic feedback mechanism. The feedback loop may be described as follows: An upstream velocity disturbance induces a modulation of the heat release rate, which in turn ...
Thomas Emmert, Sebastian Bomberg, Wolfgang Polifke   +2 more
openaire   +1 more source

Control of intrinsic instability of superelastic deformation

International Journal of Plasticity, 2002
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Slutsker, Julia, Roytburd, Alexander L.
openaire   +3 more sources

Intrinsic instability of nanocrystalline metals

Acta Metallurgica et Materialia, 1992
Abstract With a macroscopic analysis, similar to Raj [ Acta metall. 38, 1413 (1990)], premelting at higher order grain junctions, especially at four grain junctions, is discussed. The calculation is applied to nanocrystalline (nc) metals. It is found that nc-metals become unstable at the critical temperature T c . This temperature can be regarded
openaire   +1 more source

Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite

Advanced Energy Materials, 2015
Organolead halide perovskites currently are the new front‐runners as light absorbers in hybrid solar cells, as they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution‐based fabrication routes. Long‐term stability remains a major obstacle for application on an industrial scale.
Conings Bert, Drijkoningen Jeroen, Gauquelin Nicolas, Babayigit Aslihan, D'Haen Jan, D'Olieslaeger Lien, Ethirajan Anitha, Verbeeck Jo, Manca Jean, Mosconi Edoardo, De Angelis Filippo, Boyen Hans Gerd   +11 more
openaire   +3 more sources

Intrinsic instability and nonuniformity of plastic deformation

International Journal of Plasticity, 1997
In agreement with works of D. C. Drucker and Ming Li in the early 1990s, where it was concluded that plastic deformation is an intrinsically unstable process in initially homogeneous materials that obey a nonassociated flow rule, it is shown here that using the observed small non-normality, the predicted critical hardening modulus for the onset of ...
Li, Ming, Richmond, O.
openaire   +1 more source

Intrinsic Instabilities Of Heavy Metal Fluoride Glasses

Optical Engineering, 1985
Heavy metal fluoride glasses (HMFG) are potentially useful as optical components in a wide range of devices. Their utilization has so far been delayed mainly because of insufficient material purity and inadequate processing conditions. However, as the result of numerous research efforts, these problems are gradually diminishing, and it now seems likely
A. J. Bruce, C. T. Moynihan, S. R. Loehr, S. M. Opalka, R. Mossadegh, N. L. Perazzo, N. P. Bansal, R. H. Doremus, M. G. Drexhage   +8 more
openaire   +1 more source

Intrinsic Instabilities of Curved Premixed Flames

Europhysics Letters (EPL), 1993
A study of instabilities occurring in downward-propagating curved premixed flames is undertaken, on the basis of a Michelson-Sivashinsky equation including gravity effects. Contrary to the qualitative idea of Zel'dovich et al. on flame stability (Combust. Sci.
openaire   +1 more source

Control of intrinsic thermoacoustic instabilities using hydrogen fuel

Proceedings of the Combustion Institute, 2021
Abstract This conceptual numerical study explores a possible strategy for control of unstable intrinsic thermoacoustic (ITA) modes. Control of the ITA feedback loop has not been discussed yet. We propose addition of hydrogen fuel as a means of control and investigate the effect of incremental addition to the fuel mixture on the stability of a laminar
Abdulla Ghani, Wolfgang Polifke
openaire   +1 more source

Intrinsic instability and entropy stabilization of grain boundaries

Physical Review Letters, 1990
A simple method is proposed to describe the thermodynamic properties of disordered grain boundaries in nanocrystalline metals and semiconductors. Based on a free-volume approach at negative pressure of the universal equation of state, the maximum free volume, thermal expansion coefficient, specific-heat capacity, and excess enthalpy, entropy, and free ...
openaire   +2 more sources