Navigation Links
Following the leader can be a drag, according to student's research on flapping flags
Date:11/7/2008

From the Tour de France to NASCAR, competitors and fans know that speed is only part of the equation. Strategy -- and the ability to use elements like aerodynamic drafting, which makes it easier to follow closely behind a leader than to be out in front -- is also critical.

But in some cases, drafting happens in reverse: It's the leader of a pack who experiences reduced drag, while the followers encounter more resistance -- and have to expend more energy to keep up.

In research published in the Nov. 7 issue of Physical Review Letters (Vol. 101: No. 194502), Cornell fourth-year physics graduate student Leif Ristroph and New York University researcher Jun Zhang used a simple tabletop experiment to show that two or more flexible objects in a flow -- flags flapping in the wind, for example -- experience drag very differently than rigid objects in a similar flow.

The findings could help biologists understand a variety of phenomena, including why animals like fish and birds travel in groups.

"It's counterintuitive," said Ristroph. "People who have studied schooling fish and flocking birds always postulate that they flock because the ones downstream can save energy, and the guy who's at the front has to work harder. Here's a case where that gets turned on its head."

To test the effects of a flowing fluid on flexible objects, Ristroph created a thin film of soapy water -- the beginning of a giant soap bubble -- stretched between two fishing lines and constantly refreshed with a flow of water from the top. Into the membrane, he inserted pieces of thin rubber (the flags) -- attached to perpendicular wire "flagpoles."

To measure the forces on the flags as water flowed past them, Ristroph attached small mirrors -- actually microscope cover slips -- to the far ends of the "flagpoles." As the flags flapped in the flow, the slightly flexible poles moved correspondingly -- and by shining a laser light on the mirrors
'/>"/>

Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University Communications
Source:Eurekalert

Page: 1 2

Related biology news :

1. Researchers block damage to fetal brain following maternal alcohol consumption
2. Following traumatic brain injury, balanced nutrition saves lives
3. When following the leader can lead into the jaws of death
4. MNI researchers locate neurological basis of depression following sports concussion
5. Researchers take first steps towards spinal cord reconstruction following injury
6. LSU professor studies army-ant-following birds
7. Ecologist finds dire devastation of snake species following floods of 93, 95
8. Gender biases in leadership selection during competitions within and between groups
9. World leaders in infectious diseases convene to discuss emerging global viruses
10. Growing a garden of future environmental leaders
11. USGS Coalition to honor Reps. Dicks, Regula with Leadership Award
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/6/2015)... BOSTON and TELTOW, Germany ... the 2015 Siggraph Conference, SensoMotoric Instruments (SMI) ... augmented reality , based on Epson,s Moverio ... eye tracking platform. With this new solution, unprecedented quality ... multi-modal, hands-free interaction with context-sensitive displays. For the first ...
(Date:8/4/2015)... Research and ... addition of the "Digital Forensics Market ... (Computer Forensics, Network Forensics, Mobile Device Forensics, ... and Region - Global Forecast to 2020" ... By Component (Hardware, Software, and Service), Sub-Segment ...
(Date:7/31/2015)... de julho de 2015 A 10 a. ... será realizada pela BGI de 22-25 de outubro de 2015, ... A conferência está celebrando seu 10 o. aniversário ... se tornou uma das reuniões mais influentes do mundo ... mais dinâmicos, entusiastas e prazerosos. A ...
Breaking Biology News(10 mins):SMI Shows First Eye Tracking Upgrade for Augmented Reality Glasses 2SMI Shows First Eye Tracking Upgrade for Augmented Reality Glasses 3Digital Forensics Market - The Market Represents a Compound Annual Growth Rate (CAGR) of 11.3% From 2015 to 2020 2A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 2A 10a. Conferência Internacional sobre Genômica (ICG-10) será em outubro 3
... grains with solubles (DDGS) to growing pigs, many questions are ... "Previous research shows that while the amount of energy ... lower digestibility of energy in DDGS than in corn," said ... Department of Animal Sciences. "Our goal was to find out ...
... University of Pennsylvania biologists studying human reproduction ... factor to the maternal age-associated increase in aneuploidy, ... during reproductive cell division. Using naturally aging ... of reproductive life is most likely caused by ...
... who develop life-threatening bacterial infections, or septicemia, with insulin ... infection, if results of a new preliminary study can ... online ahead of print in Diabetes Care ... oxidative stress in study participants who had been injected ...
Cached Biology News:Swine researchers seek answers to fiber's low digestibility 2Why the biological clock? Penn study says aging reduces centromere cohesion, disrupts reproduction 2Insulin may reduce several inflammatory factors induced by bacterial infection 2
(Date:8/26/2015)... FRANCISCO , Aug. 26, 2015  Platform ... that it has received a $1.5M Phase II ... (NIH) to further develop its therapeutic agent to ... clinical need in end stage renal disease (ESRD) ... the National Institute of Diabetes and Digestive and ...
(Date:8/26/2015)... and BEIJING , August 26, 2015 ... Impressive Acheivements  DiaCardio wins 1 st place  ... The competition, led in Israel by venture ... startups from countries including the US, China , ... Latin America .  Impressive achievement for ...
(Date:8/26/2015)... -- After litigating and negotiating patent infringement claims ... United States patent RE43,651 (the ,651 ... the United States without any admission or concession ... As a result of the parties, settlement, the US District ... dismissed the case without prejudice. Under the ...
(Date:8/26/2015)... , ... August 26, 2015 , ... PRC Clinical, ... develop new business relationships with local sponsors in southern California. The Clinical Trial Management ... drug development processes and regulatory pathways., , Stem Cell ...
Breaking Biology Technology:Symic Biomedical Awarded $1.5MM NIH Phase II SBIR Grant to Develop its Proteoglycan Mimetic Therapeutics to Reduce Vascular Access Failures in ESRD 2Symic Biomedical Awarded $1.5MM NIH Phase II SBIR Grant to Develop its Proteoglycan Mimetic Therapeutics to Reduce Vascular Access Failures in ESRD 3Israeli Startup Takes First Place at Shengjing Global Innovation Awards 2015 2Israeli Startup Takes First Place at Shengjing Global Innovation Awards 2015 3Israeli Startup Takes First Place at Shengjing Global Innovation Awards 2015 4Israeli Startup Takes First Place at Shengjing Global Innovation Awards 2015 5Israeli Startup Takes First Place at Shengjing Global Innovation Awards 2015 6P2i Settles United States Litigation 2PRC Clinical To Attend Major Industry Conferences And Meet Sponsor Companies In The San Diego Biotech Hub 2PRC Clinical To Attend Major Industry Conferences And Meet Sponsor Companies In The San Diego Biotech Hub 3
... - N30 Pharma (N30), a,biopharmaceutical company focused on ... target endogenous,s-nitrosothiols, today announced a licensing agreement with ... use of a s-nitrosothiol drug,candidate. Financial terms of ... extremely pleased to announce this agreement. NitroMed is ...
... 29 IDM Pharma, Inc.,(Nasdaq: IDMI ), a ... announced today that Timothy P. Walbert,president and chief executive ... Conference in San Diego on Thursday, November 1, 2007,at ... Mar. A webcast of the presentation will be ...
... Monitor Offers Both Built-in ... Quality Controls, INDIANAPOLIS, Oct. 29 Roche ... controls and optional, external,liquid controls to help non-waived ... results for patients taking,blood thinner medication. The ...
Cached Biology Technology:IDM Pharma to Present at BIOCOM Investor Conference 2IDM Pharma to Present at BIOCOM Investor Conference 3Roche Diagnostics Launches CoaguChek XS Plus System to Provide New PT/INR Point-of-Care Solution for Non-Waived Anticoagulation Services 2Roche Diagnostics Launches CoaguChek XS Plus System to Provide New PT/INR Point-of-Care Solution for Non-Waived Anticoagulation Services 3Roche Diagnostics Launches CoaguChek XS Plus System to Provide New PT/INR Point-of-Care Solution for Non-Waived Anticoagulation Services 4
... Studio Enterprise is integrated informatics solution ... mechanisms and drug response modeling. This ... worlds largest knowledge base of biological ... MedScan module capable of extracting pathway-related ...
... Rapid-Screen cDNA Library Panels were designed for ... sets of PCRs to identify the desired ... performed in a 96-well "Master Plate," where ... clones. Having identified the positive well(s) by ...
Application: For use as a carrier in nucleic acid purification and precipitation. Physical form: Solution in 10 mM Tris HCl, pH 7.4, 1 mM EDTA Concentration: 9-11 mg/mL Physical Form: buffered aqu...
... Preparation Note: Prepared by a modification ... et al., Biotechnol. Bioeng., ... One unit will yield an A ... ml of water (1 cm light ...
Biology Products: