Urinal Dynamics

Bulletin of the American Physical Society
66th Annual Meeting of the APS Division of Fluid Dynamics
Volume 58, Number 18
Sunday, November 24, 2013, 5:11 PM–5:24 PM

Randy Hurd, Kip Hacking, Benjamin Haymore, Tadd Truscott

Brigham Young University

In response to harsh and repeated criticisms from our mothers and several failed relationships with women, we present the splash dynamics of a simulated human male urine stream impacting rigid and free surfaces. Our study aims to reduce undesired splashing that may result from lavatory usage. Experiments are performed at a pressure and flow rate that would be expected from healthy male subjects. For a rigid surface, the effects of stream breakup and surface impact angle on lateral and vertical droplet ejection distances are measured using high-speed photography and image processing. For free surface impact, the effects of velocity and fluid depth on droplet ejection distances are measured. Guided by our results, techniques for splash reduction are proposed.

http://meetings.aps.org/link/BAPS.2013.DFD.E9.3

Why does a beer bottle foam up after a sudden impact on its mouth?

Bulletin of the American Physical Society
66th Annual Meeting of the APS Division of Fluid Dynamics
Volume 58, Number 18
Sunday, November 24, 2013, 9:05 AM–9:18 AM

Javier Rodriguez-Rodriguez
Carlos III University of Madrid, Spain

Almudena Casado-Chacon
Carlos III University of Madrid, Spain

Daniel Fuster
CNRS (UMR 7190), Universite Pierre et Marie Curie, Institut Jean le Rond d'Alembert, France

A sudden vertical impact on the mouth of a beer bottle generates a compression wave that propagates through the glass towards the bottom. When this wave reaches the base of the bottle, it is transmitted to the liquid as an expansion wave that travels to free surface, where it bounces back as a compression wave. This train of expansion-compression waves drives the forced cavitation of existing air pockets, leading to their violent collapse. A cloud of very small daughter bubbles are generated upon these collapses, that expand much faster than their mothers due to their smaller size. These rapidly growing bubble clusters effectively act as buoyancy sources, what leads to the formation of bubble-laden plumes whose void fraction increases quickly by several orders of magnitude, eventually turning most of the beverage into foam. In this talk, we will analyze quantitatively these processes in order to explain the extremely high efficiency of the degasification process that occurs in the bottle within the few seconds that follow the impact.

This work has been supported by Spanish Ministries of Science and of Economy and Competitiveness through grants: DPI2008-06369 and DPI2011-28356-C03-02.

http://meetings.aps.org/link/BAPS.2013.DFD.A11.6

Energy Optimality in Novel Movement: Sideways Walking

The Ohio State University Department of Mechanical and Aerospace Engineering Honors Theses
November 2012
date available 2012-11-09T20:34:17Z
http://hdl.handle.net/1811/53177

Matthew Handford

Abstract

The theory of energy optimality states that humans naturally move in a manner that minimizes the energy that their bodies use. This theory has been shown to be approximately true for natural gaits but it has not been tested on many unnatural gaits. To test if this theory would work on novel gaits, we conducted an experiment to compare people’s natural preferred speed to their energy optimal speed as they walked sideways. Subjects were asked to choose a comfortable speed using while walking sideways which was then recorded as the preferred velocity. Then, using a portable metabolic measurement system (the Oxycon Mobile VO2 device), their metabolic energy usage was recorded at a variety of speeds. Using this data, energy optimal velocities were found and compared with preferred velocities. While these quantities didn’t match exactly, a person’s preferred speed could be predicted by the population’s optimal speed with an average absolute error of 0.117 m/s. With the caveat that the subject pool was small with high data variability, the mean optimal speed (0.592 m/s) differed from the preferred speeds by only about an average of 0.041 m/s. In future experimentation, we hope to investigate the effects of perception and prior experience and the length of time it takes to reach the energy optimal speed with the subjects’ natural movement.

Keywords

Human Locomotion; Energy; Walking; Optimality

http://hdl.handle.net/1811/53177

http://kb.osu.edu/dspace/handle/1811/53177

Too Impatient to Smell the Roses - Exposure to Fast Food Impedes Happiness

Social Psychological and Personality Science
November 14, 2013
doi: 10.1177/1948550613511498

Julian House, Sanford E. DeVoe, Chen-Bo Zhong

Rotman School of Management, University of Toronto, 105 St. George Street, Toronto, Ontario, Canada M5S3E6

Abstract

We tested whether exposure to the ultimate symbols of an impatience culture—fast food—undermines people’s ability to experience happiness from savoring pleasurable experiences. Study 1 found that the concentration of fast-food restaurants in individuals’ neighborhoods predicted their tendencies to savor. Study 2 revealed that exposure to fast-food primes impeded participants’ ability to derive happiness from pictures of natural beauty. Study 3 showed that priming fast food undermined positive emotional responses to a beautiful melody by inducing greater impatience, measured by both subjective perception of time passage and self-reports of impatience experienced during the music. Together, these studies show that as pervasive symbols of impatience, fast food can inhibit savoring, producing negative consequences for how we experience pleasurable events.

http://spp.sagepub.com/content/early/2013/11/13/1948550613511498.abstract

Is “Huh?” a Universal Word? Conversational Infrastructure and the Convergent Evolution of Linguistic Items

PLoS ONE 01/2013; 8(11):e78273
Published: November 8, 2013
DOI:10.1371/journal.pone.0078273

Mark Dingemanse, Francisco Torreira, N. J. Enfield

Language and Cognition Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
(N. J. Enfield, Centre for Language Studies, Radboud University, Nijmegen, The Netherlands)

Abstract

A word like Huh?–used as a repair initiator when, for example, one has not clearly heard what someone just said– is found in roughly the same form and function in spoken languages across the globe. We investigate it in naturally occurring conversations in ten languages and present evidence and arguments for two distinct claims: that Huh? is universal, and that it is a word. In support of the first, we show that the similarities in form and function of this interjection across languages are much greater than expected by chance. In support of the second claim we show that it is a lexical, conventionalised form that has to be learnt, unlike grunts or emotional cries. We discuss possible reasons for the cross-linguistic similarity and propose an account in terms of convergent evolution. Huh? is a universal word not because it is innate but because it is shaped by selective pressures in an interactional environment that all languages share: that of other-initiated repair. Our proposal enhances evolutionary models of language change by suggesting that conversational infrastructure can drive the convergent cultural evolution of linguistic items.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0078273

Rumor Diffusion in an Interests-Based Dynamic Social Network

The Scientific World Journal
Volume 2013 (2013), Article ID 824505, 10 pages
http://dx.doi.org/10.1155/2013/824505

Mingsheng Tang [1], Xinjun Mao [1], Zahia Guessoum [2], and Huiping Zhou [1]

[1] College of Computer, National University of Defense Technology, Changsha 410073, China
[2] LIP 6, Université Pierre et Marie Curie Paris, 75006 Paris, France

Received 12 July 2013; Accepted 3 November 2013

Academic Editors: H. M. Chamberlin and Y. Zhang

Copyright © 2013 Mingsheng Tang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

To research rumor diffusion in social friend network, based on interests, a dynamic friend network is proposed, which has the characteristics of clustering and community, and a diffusion model is also proposed. With this friend network and rumor diffusion model, based on the zombie-city model, some simulation experiments to analyze the characteristics of rumor diffusion in social friend networks have been conducted. The results show some interesting observations: (1) positive information may evolve to become a rumor through the diffusion process that people may modify the information by word of mouth; (2) with the same average degree, a random social network has a smaller clustering coefficient and is more beneficial for rumor diffusion than the dynamic friend network; (3) a rumor is spread more widely in a social network with a smaller global clustering coefficient than in a social network with a larger global clustering coefficient; and (4) a network with a smaller clustering coefficient has a larger efficiency.

http://www.hindawi.com/journals/tswj/2013/824505/

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3881697/

Reduced cognitive control in passionate lovers

Motivation and Emotion
November 2013
Published online: 02 November 2013
DOI 10.1007/s11031-013-9380-3

Henk van Steenbergen (1,2), Sandra J. E. Langeslag (3), Guido P. H. Band (1,2), Bernhard Hommel (1,2)

1. Leiden Institute for Brain and Cognition, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands
2. Leiden University Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands
3. Department of Psychology, University of Maryland, College Park, MD, USA

RUNNING HEAD: Love and control

Abstract

Passionate love is associated with intense changes in emotion and attention which are thought to play an important role in the early stages of romantic relationship formation. Although passionate love usually involves enhanced, near-obsessive attention to the beloved, anecdotal evidence suggest that the lover’s concentration for daily tasks like study and work may actually be impaired, suggesting reduced cognitive control. Affect might also contribute to changes in cognitive control. We examined the link between passionate love and cognitive control in a sample of students who had recently become involved in a romantic relationship. Intensity of passionate love as measured by the Passionate Love Scale was shown to correlate with decreased individual efficiency in cognitive control as measured in Stroop and flanker task performance. There was no evidence that affective changes mediate this effect. This study provides the first empirical evidence that passionate love in the early stages of romantic relationship is characterized by impaired cognitive control.

Keywords

Passionate love, Cognitive control, Flanker task, Stroop task, Passionate Love Scale (PLS)

http://link.springer.com/article/10.1007/s11031-013-9380-3

Chasing maximal performance: a cautionary tale from the celebrated jumping frogs of Calaveras County

J Exp Biol 216, 3947-3953
November 1, 2013
doi: 10.1242/​jeb.090357

H. C. Astley [1*], E. M. Abbott [**], E. Azizi [**], R. L. Marsh [2] and T. J. Roberts [1]

[1] Brown University, Department of Ecology and Evolutionary Biology, Providence, RI 02912, USA
[2] Northeastern University, Department of Biology, Boston, MA 02115, USA
[*] Author for correspondence at present address: Department of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
[**] Present address: Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, USA

Summary

Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: ‘rental’ frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, ‘professional’ teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates.

http://jeb.biologists.org/content/216/21/3947

Infertility in Star Trek

World Future Review
November, Winter 2012 vol. 4 no. 4 19-27
doi: 10.1177/194675671200400405

Victor Grech

Abstract

It is fair to say that Star Trek comprises a selfcontained subgenre within science fiction (SF). Over nearly 50 years, through six distinct television series, and eleven feature length films, the “Star Trek universe” envisioned by Gene Roddenberry has become arguably the world's most elaborate and widely recognized depiction of life in future times (covering roughly the twenty-second through the twenty-ninth centuries). In this article, situations involving infertility occurring in episodes from different Star Trek series are examined and some general conclusions offered concerning the perception of this problem and the variety of responses proposed.

STAR TREK; INFERTILITY; MEDICINE IN SCIENCE FICTION

http://wfr.sagepub.com/content/4/4/19.abstract