Mode-coupling theory of the stress-tensor autocorrelation function of a dense binary fluid mixture

We present a generalized mode-coupling theory for a dense binary fluid mixture. The theory is used to calculate molecular-scale renormalizations to the stress-tensor autocorrelation function (STAF) and to the long-wavelength zero-frequency shear viscosity. As in the case of a dense simple fluid, we find that the STAF appears to decay as $t^{-3/2}$ over an intermediate range of time. The coefficient of this long-time tail is more than two orders of magnitude larger than that obtained from conventional mode-coupling theory. Our study focuses on the effect of compositional disorder on the decay of the STAF in a dense mixture.Comment: Published; withdrawn since ordering in the archive gives misleading impression of new publicatio

Simulation-based UAS Swarm Selection for Monitoring and Detection of Migrant Border Crossings

The European migration crisis reached critical levels in 2015 due to a major influx of migrants taking the journey across the Mediterranean to Italy, Greece, and other European coasts. Migration flow rates across the Mediterranean have dropped in recent years, but fatalities have increased and border pressure is still high. Recent operations by local governments, international agencies, and NGO organizations have saved many lives and improved data collection practices, yet they have not been fully successful in responding to the high volume of travel and unexpected rate spikes in migrant trips. Different Operational Constructs and asset strategies have been studied resulting in relevant organizations investing in Unmanned Aerial Systems (UAS) for monitoring and detection. However, many questions about the most effective deployment of these assets still remain. This study is centered on the development of a modeling and simulation environment, as well as a decision support tool for conducting system-of-systems comparisons of UAS swarm and surface fleet asset combinations. The environment is an agent-based simulation built in the In-House tool Janus, which leverages the NASAWorld-Wind SDK. The simulation tool and dashboard provide a trade-off environment for parametric analysis of swarm capabilities. A case study is performed for operations by the Italian Coast Guard off the coast of Libya. Results confirm the success of implementing UAS and coordinated swarm systems. Further analysis examines the trade-off of mission effectiveness and cost, with consideration of the resilience and robustness of the system-of-systems

A comparison of HDR brachytherapy and IMRT techniques for dose escalation in prostate cancer: A radiobiological modeling study

A course of one to three large fractions of high dose rate (HDR) interstitial brachytherapy is an attractive alternative to intensity modulated radiation therapy (IMRT) for delivering boost doses to the prostate in combination with additional external beam irradiation for intermediate risk disease. The purpose of this work is to quantitatively compare single-fraction HDR boosts to biologically equivalent fractionated IMRT boosts, assuming idealized image guided delivery (igIMRT) and conventional delivery (cIMRT). For nine prostate patients, both seven-field IMRT and HDR boosts were planned. The linear-quadratic model was used to compute biologically equivalent dose prescriptions. The cIMRT plan was evaluated as a static plan and with simulated random and setup errors. The authors conclude that HDR delivery produces a therapeutic ratio which is significantly better than the conventional IMRT and comparable to or better than the igIMRT delivery. For the HDR, the rectal gBEUD analysis is strongly influenced by high dose DVH tails. A saturation BED, beyond which no further injury can occur, must be assumed. Modeling of organ motion uncertainties yields mean outcomes similar to static plan outcomes