The directional contact distance of two ellipsoids: Coarse-grained potentials for anisotropic interactions

Copyright @ 2005 American Institute of Physics.We obtain the distance of closest approach of the surfaces of two arbitrary ellipsoids valid at any orientation and separation measured along their intercenter vector. This directional distance is derived from the elliptic contact function. The geometric meaning behind this approach is clarified. An elliptic pair potential for modeling arbitrary mixtures of elliptic particles, whether hard or soft, is proposed based on this distance. Comparisons with Gay-Berne potentials are discussed. Analytic expressions for the forces and torques acting on the elliptic particles are given.This research has been supported by GlaxoSmith-Klin

Predation on the Pupae of Saturniidae (Lepidoptera) by Gray Squirrels in Wisconsin

(excerpt) Owing to their large body size, the larvae and pupae ofgiant silkworm moths (Saturniidae) are ideal food for many animals. Winter predation on the pupae of Hyalophora cecropia (L.) in Illinois by birds (Waldbauer and Sternburg, Ecology 48:312-315, 1967) is a well known example

Parasitism of Female Neotibicen linnei (Hemiptera: Cicadidae) by Larvae of the Sarcophagid Fly Emblemasoma erro in Wisconsin

Herein it is reported an unusual case of parasitism of a female Neotibicen linnei (Smith and Grossbeck) by the sarcophagid Emblemasoma erro (Aldrich) in western Wisconsin. Sarcophagids typically attack male cicadas, locating them by the latter’s acoustical behavior. Some members of the dipteran family Sarcophagidae are parasitic on male cicadas (e.g. Soper et. al. 1976, Lakes-Harlan et. al. 2000, Faris et. al. 2008, Stucky 2015). Parasitoids such as Emblemasoma species are attracted to larviposit on male cicadas by responding to the latter’s acoustical signals (Tron et. al. 2016). Sarcophagids, therefore, are generally not attracted to mute female cicadas. In this brief communique, I report an unusual instance of a female of the cicada Neotibicen linnei being successfully parasitized by Emblemasoma erro in western Wisconsin

Internal report cluster 1: Urban freight innovations and solutions for sustainable deliveries (1/4)

Technical report about sustainable urban freight solutions, part 1 of

Different Melting Behavior in Pentane and Heptane Monolayers on Graphite; Molecular Dynamics Simulations

Molecular dynamics simulations are utilized to study the melting transition in pentane (C5H12) and heptane (C7H16), physisorbed onto the basal plane of graphite at near-monolayer coverages. Through use of the newest, optimized version of the anisotropic united-atom model (AUA4) to simulate both systems at two separate coverages, this study provides evidence that the melting transition for pentane and heptane monolayers are significantly different. Specifically, this study proposes a very rapid transition from the solid crystalline rectangular-centered (RC) phase to a fluid phase in pentane monolayers, whereas heptane monolayers exhibit a slower transition that involves a more gradual loss of RC order in the solid-fluid phase transition. Through a study of the melting behavior, encompassing variations where the formation of gauche defects in the alkyl chains are eliminated, this study proposes that this gradual melting behavior for heptane monolayers is a result of less orientational mobility of the heptane molecules in the solid RC phase, as compared to the pentane molecules. This idea is supported through a study of a nonane monolayer, which gives the gradual melting signature that heptane monolayers also seem to indicate. The results of this work are compared to previous experiment over pentane and heptane monolayers, and are found to be in good agreement

Earthquake Early Warning and Beyond: Systems Challenges in Smartphone-based Seismic Network

Earthquake Early Warning (EEW) systems can effectively reduce fatalities, injuries, and damages caused by earthquakes. Current EEW systems are mostly based on traditional seismic and geodetic networks, and exist only in a few countries due to the high cost of installing and maintaining such systems. The MyShake system takes a different approach and turns people's smartphones into portable seismic sensors to detect earthquake-like motions. However, to issue EEW messages with high accuracy and low latency in the real world, we need to address a number of challenges related to mobile computing. In this paper, we first summarize our experience building and deploying the MyShake system, then focus on two key challenges for smartphone-based EEW (sensing heterogeneity and user/system dynamics) and some preliminary exploration. We also discuss other challenges and new research directions associated with smartphone-based seismic network.Comment: 6 pages, conference paper, already accepted at hotmobile 201

Some comments on Monte Carlo and molecular dynamics methods

We highlight some links between molecular dynamics and Monte Carlo algorithms used to simulate condensed matter systems. Special attention is paid to the question of sampling the desired statistical ensemble

A simple method of calculating power-law velocity profile exponents from experimental data

Analytical expressions for the effects of compressibility and heat transfer on laminar and turbulent shape factors H have been developed. Solving the turbulent equation for the power law velocity profile exponent N has resulted in a simple technique by which the N values of experimental turbulent profiles can be calculated directly from the integral parameters. Thus the data plotting, curve fitting, and slope measuring, which is the normal technique of obtaining experimental N values, is eliminated. The N values obtained by this method should be within the accuracy with which they could be measured