TeV Scale Lee-Wick Fields out of Large Extra Dimensional Gravity

We study the gravitational corrections to the Maxwell, Dirac and Klein-Gorden theories in the large extra dimension model in which the gravitons propagate in the (4+n)-dimensional bulk, while the gauge and matter fields are confined to the four-dimensional world. The corrections to the two-point Green's functions of the gauge and matter fields from the exchanges of virtual Kaluza-Klein gravitons are calculated in the gauge independent background field method. In the framework of effective field theory, we show that the modified one-loop renormalizable Lagrangian due to quantum gravitational effects contains a TeV scale Lee-Wick partner of every gauge and matter field as extra degrees of freedom in the theory. Thus the large extra dimension model of gravity provides a natural mechanism to the emergence of these exotic particles which were recently used to construct an extension of the Standard Model.Comment: 17 pages, 3 figures, references added, to appear in Phys. Rev.

The properties of kaonic nuclei in relativistic mean-field theory

The static properties of some possible light and moderate kaonic nuclei, from C to Ti, are studied in the relativistic mean-field theory. The 1s and 1p state binding energies of $K^-$ are in the range of $73\sim 96$ MeV and $22\sim 63$ MeV, respectively. The binding energies of 1p states increase monotonically with the nucleon number A. The upper limit of the widths are about $42\pm 14$ MeV for the 1s states, and about $71\pm 10$ MeV for the 1p states. The lower limit of the widths are about $12\pm 4$ MeV for the 1s states, and $21\pm 3$ MeV for the 1p states. If $V_{0}\leq 30$ MeV, the discrete $K^-$ bound states should be identified in experiment. The shrinkage effect is found in the possible kaonic nuclei. The interior nuclear density increases obviously, the densest center density is about $2.1\rho_{0}$.Comment: 9 pages, 2 tables and 1 figure, widths are considered, changes a lo

Integrating BIM with building performance analysis in project life-cycle

Adopting Building Information Modelling (BIM) in Building Performance Analysis (BPA) is becoming an emerging research area in the application of information technology in the Architecture, Engineering, and Construction (AEC) industry. To investigate the current state of research in the adoption of BIM in BPA, this study performed a holistic review consisting of a bibliometric analysis of existing literature, content analysis of selected studies, as well as follow-up qualitative discussion in BIM integration with BPA. The bibliometric analysis identified 60 relevant studies; the content analysis of these studies revealed the research focuses of BIM-enabled BPA, including interoperability, semantics, and sustainability rating systems; the qualitative discussion further highlighted the learning process throughout project delivery stages and addressed the potential gap between ‘as-designed’ building performance and ‘as-built’ performance. Overall, this study contributes to existing research by identifying key input attributes and workflow in BPA, reviewing the state-of-the-art research on BIM integration with BPA, and investigating the major research areas, namely, interoperability issues in BIM-enabled BPA within the context of life-cycle BPA

Performance evaluation of solar chimney in tunnel for passive ventilation and smoke exhaustion: A numerical approach

Solar chimney applied in building ventilation can passively regulate indoor air quality without electricity cost and carbon emissions, but its application in tunnel is limited. This study conducted a numerical modelling and theoretical analysis to investigate the volumetric flow rate through multi-channel solar chimney group in tunnel under normal and fire conditions. The influences of the solar chimney arrangements on ventilation and smoke exhaustion capacity were analyzed. Results show that the solar chimney group can afford natural ventilation in tunnel without compromising the performance of smoke exhaustion through shaft. With absorbed more solar energy, increasing cavity amount and cavity width can effectively improve the ventilation performance but limited effect on smoke exhaustion. The volumetric flow rate increases with cavity height and cavity depth that is proportional to hc1/3 and L2/3 under natural ventilation. The volumetric flow rate under natural ventilation and smoke exhaustion both increase with total chimney channel area. A theoretical model considering horizontally semi-parabolic temperature distribution inside each channel was developed to correlate the volumetric flow rate, the predictions agree reasonably with numerical results under normal and fire conditions. This study contributes to the application of solar chimney group in urban tunnels and guides extraction design