Dynamics Of Physical Properties Research Articles

Dynamic Properties for BEC in an Optical Cavity with Atom-Photon Nonlinear Interaction

In this paper we investigate the dynamics of physical properties of the system introduced in Dimer et al. (Phys. Rev. A 75, 013804, 2007) and Zhao et al. (Phys. Rev. A 90, 023622, 2014) consisting of an ensemble of four-level atoms in Bose-Einstein condensate (BEC) state and a single-mode quantized field in which nonlinear interaction is taken into account. In fact, we start with a four-level atom and then explain how this model can be reduced to an effective two-level one via the adiabatic elimination. Also, our presentation is free of any classical approximation and so it is fully quantized. In this regard, we introduce the dynamical Hamiltonian of the system in terms of angular momentum operators and use the Dicke model to achieve the state of atomic sub-system. After obtaining the analytical solution of the state vector associated with the quantized BEC-field system, various physical properties such as atomic population inversion, quantum statistics of the field, squeezing in atomic and field subsystems as well as the degree of entanglement between the “BEC atoms” and the “photons” are numerically evaluated. It is shown that, the nonlinear interaction and other involved parameters in the presented model can dramatically affect the dynamics of the system. The collapse-revival phenomenon in the population inversion, Mandel parameter and atomic squeezing is a superb feature of the system which can be controlled by tuning the chosen parameters. Meanwhile, we propose an efficient way for the generation of sub-Poissonian and squeezed fields as well as squeezed atoms via nonlinear interaction of quantized filed with atomic BEC. In addition, it is found that, after the onset of interaction the system is always entangled. Altogether, under particular conditions, the approximated sudden death and then revival of entanglement can be observed.

The dynamics of physical properties, seed moisture content, market economics and post harvest management of six bean varieties (Phaseolus vulgaris) grown in the sub Saharan region in Africa

Managing grain moisture content is important because maximum economic return can be achieved by marketing at a certain moisture level of grain. Post-harvest management dictates that grains must be dried to certain levels to avoid development of fungal and insect problems, respiration and germination. However, over drying can also a lead to economic losses. Most farmers are aware of fungal development in moist grains but few are aware that they make less profit by over drying. Moreover, there are also bean varieties which genetically retain more water than others and hence can be safer and have more economic returns compared to others. But, this also should be matched to the rain pattern in a growing region. We compared six varieties of beans (KAT B1, KAT B9, and Kakunzu (KKZ), Rose Coco (GLP2/RCC), Kenya Tamu and KAT X56) grown in the South Eastern region of Kenya and found significant differences in dry moisture content, physical properties and grain weights. The Rose Coco and KAT X56 varieties had the highest moisture content retention but the KKZ variety the lowest. This explained why KKZ is favoured more by famers in arid areas with less rain during fruit maturation.

Investigation into the dynamics of physical properties of an epoxy resin during solidification

Results of experimental investigation into solidification of structures based on ED-20 epoxy resin with different contents of the polyethylene polyamine solidifier are presented. Continuous measurements using a specially developed automated system are presented. The data on changes of mechanical, acoustic, and electrical properties of epoxy amine compound during solidification are given.

Modal interpretation of quantum mechanics, measurements, and macroscopic behavior.

The modal interpretation explained here construes the mathematical formalism of quantum mechanics in terms of physical properties (``be-ables,'' ``existents'') in such a way that the property attribution reflects the mathematical structure as much as possible---no additional structure is superimposed on the formalism. We generalize the interpretation by specifying a dynamics of physical properties, and also extend it while replying to recent objections by Albert and Loewer 2 [Proceedings of the 1990 Biennial Meeting of the Philosophy of Science Association, edited by A. Fine, M. Forbes, and L. Wessels (Philosophy of Science Association, East Lansing, MI, 1990), Vol. 1, p. 277], and by Elby [Found. Phys. Lett. 6, 5 (1993)]. I also discuss questions relating to relativistic aspects and casuality.