Two simple systems with cold atoms: quantum chaos tests and nonequilibrium dynamics

This article is an attempt to provide a link between the quantum nonequilibrium dynamics of cold gases and fifty years of progress in the lowdimensional quantum chaos. We identify two atomic systems lying on the interface: two interacting atoms in a harmonic multimode waveguide and an interacting two-component Bose-Bose mixture in a double-well potential. In particular, we study the level spacing distribution, the wavefunction statistics, the eigenstate thermalization, and the ability to thermalize in a relaxation process as such.Comment: 18 pages, 9 figure

Effect of Mean Exicitation Energy of Water on Proton Range Uncertainties

One of the challenges in proton therapy planning is the range uncertainty. This uncertainty comes from two essential factors. The CT-calibration in one side and the semi-empirical model of deriving the stopping power (SP) in the other side. The latter is dominant by the intrinsic basic physics uncertainty in the so called the mean excitation energy. Range uncertainty due to the CT-calibration is generally taken as 3.5 % of proton to generate the Planning Target Volume PTV, which translating to adding a distal margin of 7-10 mm. The current study is focus on studying the effect of mean excitation energy of water on proton range uncertainties. To do this, we study two different model of calculating the I-values, the published and used I-values in the clinical treatment as it is stated in ICRU report 49 namely 75eV , and the suggested Janni\u27s I values which is equal to 81.75 eV. The preliminary result of the comparison between the mass stopping power shows that the suggested Janni\u27s I-values differed in so far as 1-1.5 % from the ICRU (49) values which used in the treatment planning for both the soft and bony tissues

Optical engineering of polymer materials and composites for simultaneous color and thermal management

© 2019 Optical Society of America. Sustainable architecture requires development of new materials with tailored optical, mechanical, and thermal properties to provide both aesthetic appeal and energy-saving functionalities. Polymers and polymer-based composites emerge as promising lightweight and conformable materials whose optical spectra can be engineered to achieve both goals. Here, we report on the development of new types of organic-inorganic films composed of ultrahigh molecular weight polyethylene with a variety of organic and inorganic nano- and micro-scale inclusions. The films simultaneously provide ultra-light weight, conformability, either visual coloring or transparency on demand, and passive thermal management via both conduction and radiation. The lightweight semi-crystalline polymer matrix yields thermal conductivity exceeding that of many metals, allowing for the lateral heat spreading and hot spots mitigation in the cases of partial illumination of films by sunlight. It also yields excellent broadband transparency, allowing for the opportunities to shape the spectral response of composite materials via targeted addition of inclusions with tailored optical spectra. We demonstrate a variety of dark- and bright-colored composite samples that exhibit reduced temperatures under direct illumination by sunlight, and outline strategies for materials design to further improve material performance