Precise Numerical Solution of Soil Consolidation Effect

Department of Engineering Machanics, Nothwestern Polytechnical University, ChinaPromoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Energy Loss in Pulse Detonation Engine due to Fuel Viscosity

Fluid viscosity is a significant factor resulting in the energy loss in most fluid dynamical systems. To analyze the energy loss in the pulse detonation engine (PDE) due to the viscosity of the fuel, the energy loss in the Burgers model excited by periodic impulses is investigated based on the generalized multisymplectic method in this paper. Firstly, the single detonation energy is simplified as an impulse; thus the complex detonation process is simplified. And then, the symmetry of the Burgers model excited by periodic impulses is studied in the generalized multisymplectic framework and the energy loss expression is obtained. Finally, the energy loss in the Burgers model is investigated numerically. The results in this paper can be used to explain the difference between the theoretical performance and the experimental performance of the PDE partly. In addition, the analytical approach of this paper can be extended to the analysis of the energy loss in other fluid dynamic systems due to the fluid viscosity

Dynamic Analysis and Active Control of a Dielectric Elastomer Balloon Covered by a Protective Passive Layer

Dielectric elastomer (DE) balloons are intensively developed as sensors, actuators, and generators.  To ensure electrical safety, a DE balloon can be covered by an external passive layer. In this paper, the dynamic behaviours and active control for the DE balloon coupled with the passive layer are investigated. Based on the Hamilton’s principle, the dynamic model of the DE balloon covered by the passive layer is derived. With this coupled model, we demonstrate that three typical dynamic responses can appear and the transition among these dynamic behaviours can be achieved by altering the properties of the passive layer. The introduction of the passive layer is able to induce undesirable dynamic behaviours, which require to be controlled. Thus, we present two methods of control including proportional-derivative (PD) control and iterative learning control (ILC). We demonstrate that the undesirable dynamic responses can be effectively eliminated by the proposed methods of control. Particularly, control errors can be reduced by 2 or 3 orders of magnitude using the latter control method. We hope that the present analysis can improve the understanding of dynamic behaviours of a DE balloon covered by a passive layer and promote the control of undesirable dynamic responses

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data