When one hard steel ball collides with another, kinetic energy is conserved, even if the balls have different diameters. Why is kinetic energy conserved in such a collision, given that kinetic energy is not conserved when two unequal length steel springs or rods collide? Experimental results with bouncing balls, springs, and rods are presented, which reveal the answer. For colliding springs and...

We give a complete characterization of the possible response matrices at a fixed frequency of n-terminal electrical networks of inductors, capacitors, resistors and grounds, and of n-terminal discrete linear elastodynamic networks of springs and point masses, both in the three-dimensional case and in the two-dimensional case. Specifically we construct networks which realize any response matrix ...

A mesoscopic analytical model of wrinkling of Plain-Woven Composite Preforms (PWCPs) under the bias extension test is presented, based on a new instability analysis. The analysis is aimed to facilitate a better understanding of the nature of wrinkle formation in woven fabrics caused by large in-plane shear, while it accounts for the effect of fabric and process parameters on the onset of wrinkl...

Personality assessment among older adults: the value of personality questionnaires unraveled Gina Rossi, Joke Van den Broeck, Eva Dierckx, Daniel L. Segal & Sebastiaan P.J. van Alphen a Department of Clinical and Life Span Psychology, Vrije Universiteit Brussel (VUB), Brussel, Belgium b Alexian Brothers Hospital, Tienen, Belgium. c Psychology Department University of Colorado, Colorado Springs ...

I compiled information from the literature on 140 population outbreaks of 26 species of forest Lepidoptera that occurred between the years 1932 and 1992 in the Northern Hemisphere, including Asia, North America, and Europe. Considerable variation in the number of outbreaks occurred among years, with a tendency for outbreaks to be synchronous. Years of numerous outbreaks include 1948, 1956, 1964...

Answer me, mechanist, has Nature arranged all the springs of feeling in this animal to the end that he might not feel? Has he nerves that he may be incapable of suffering? Voltaire (1694-1778)

1Austin, J.A., Jr., Christie-Blick, N., Malone, M.J., et al., 1998. Proc. ODP, Init. Repts., 174A: College Station, TX (Ocean Drilling Program). 2Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, U.S.A. [email protected] 3University of Texas Institute for Geophysics, 4412 Spicewood Springs Road, Building 600, Aus...

We analyze theoretically the effects of excluded-volume interactions between motors on the dynamics of a cargo driven by multiple motors. The model considered shares much in common with others recently proposed in the literature, with the addition of direct interaction between motors and motor back steps. The cargo is assumed to follow a continuum Langevin dynamics, while individual motors evol...

Engineering surfaces that promote rapid drop detachment1,2 is of importance to a wide range of applications including anti-icing3-5, dropwise condensation6, and self-cleaning7-9. Here we show how superhydrophobic surfaces patterned with lattices of submillimetre-scale posts decorated with nano-textures can generate a counter-intuitive bouncing regime: drops spread on impact and then leave the s...

OBJECTIVE This secondary, qualitative analysis examined physician-patient interaction and patient-centered care in a random sample of encounters of 44 physicians in 18 family practices. METHODS Fieldworkers were trained in qualitative and quantitative data collection strategies including participatory observation, narrative description, interviewing techniques and note-taking regarding practi...