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:7/25/2014)... is a complex congenital central nervous system disease ... the neural tubes during the embryonic phase. Many ... fecal incontinence and neurocognitive retardation. Such problems decrease ... life. Researchers at Ankara Physical Medicine and Rehabilitation ... performance in children with SB, using the Pediatric ...
(Date:7/25/2014)... girls reach puberty is influenced by ,imprinted genes,a subset of ... gene. This is the first evidence that imprinted genes ... of this study were published today in the journal ... menarche, is a marker for the timing of puberty in ... varies between girls, is an inherited trait, and is linked ...
(Date:7/25/2014)... a molecular testing panel developed at UPMC greatly ... surgery for patients with thyroid nodules and cancer, ... Institute (UPCI), partner with UPMC CancerCenter., The test, ... other diagnostic testing agencies, improved the chances of ... percent, according to the study published this month ...
Breaking Biology News(10 mins):Could age of first period influence development of diseases in older women? 2Test increases odds of correct surgery for thyroid cancer patients 2Test increases odds of correct surgery for thyroid cancer patients 3
... European College of Neuropsychopharmacology (ECNP) is pleased to ... 2009 ECNP Neuropsychopharmacology Award in Basic Science Research ... into the neurochemical basis of substance addiction. ... in the field of neuropsychopharmacology and its closely ...
... Researchers have made significant advances in the treatment of metastatic ... treat successfully once it has started to spread according ... congress, ECCO 15 ESMO 34 [1], in Berlin on ... seen rapid and dramatic shrinking of metastatic tumours in patients ...
... research team at the National Institute of Standards and ... possible cancer therapy has uncovered a delicate balancing act ... says they should be. Just like individuals in a ... because they get close together, but not too close. ...
Cached Biology News:Trial of new treatment for advanced melanoma shows rapid shrinking of tumors 2Trial of new treatment for advanced melanoma shows rapid shrinking of tumors 3Therapeutic nanoparticles give new meaning to sugar-coating medicine 2
(Date:7/25/2014)... Sinovac Biotech Ltd. (Nasdaq: SVA ), a leading ... today announced that it will release its unaudited financial results ... close on Thursday, August 14, 2014 EDT. The Company will ... Friday, August 15, 2014, at 8:00 a.m. EDT (Friday, August ... the Company,s financial results and provide an update on recent ...
(Date:7/24/2014)... July 24, 2014 -- A novel combination of microscopy ... of Energy,s Oak Ridge National Laboratory an unprecedented look ... unusual physical and electrochemical properties. , The research ... affects the surface of a perovskite manganite, a complex ... new avenue to understand surface behavior could benefit researchers ...
(Date:7/24/2014)... , July 24, 2014  Now available is a ... Rehealth Regenerative Therapies , located in ... physically active people a new health option: stem ... of age, countless patients suffer from joint and muscle ... as muscle tears, torn rotator cuff, tennis elbow, and ...
(Date:7/24/2014)... -- ECC West Africa, LLC (ECC) signed a contract in ... Hospital (UCH) Ibadan Board of Management for the first ... and operate and maintain a new, state-of-the-art Cancer Institute ... first of the 4-phase project, ECC will conduct feasibility ... Ibadan intends to finance and develop the Cancer Institute ...
Breaking Biology Technology:Sinovac to Host Conference Call to Report Second Quarter 2014 Unaudited Financial Results 2ORNL study reveals new characteristics of complex oxide surfaces 2Stem Cells In Sports Injuries, Joints And Muscular Pain 2Stem Cells In Sports Injuries, Joints And Muscular Pain 3ECC Signs a Contract for the Finance, Design, and Construction of a Premier Cancer Institute in Ibadan, Nigeria 2
... Researcher Appreciation Event ... ... PHOENIX, Oct. 3 ThirdBiotech Inc., http://www.thirdbiotech.com, a biotechnology incubator ... Appreciation Event to be held on Thursday, October 23rd, 2008,between noon and ...
... http://www.amdl.com ),AMDL, Inc. (Amex: ADL ), a leading ... the US, today announced that the,Company will present at ... on Tuesday, October 7, 2008 at 10:30 a.m. ET. ... York Hotel in the Morosco Room., The Maxim ...
... Support R&D Efforts and Clinical Trials Advancing,the ... Oct. 3 Micromet, Inc. (Nasdaq:,MITI) ("Micromet" ... proprietary antibodies for the treatment of cancer, ... has closed its previously,announced $40 million private ...
Cached Biology Technology:First Annual Arizona Biotech Day Announced for October 23rd 2008 2First Annual Arizona Biotech Day Announced for October 23rd 2008 3AMDL, Inc. to Present at Maxim Group Growth Conference October 7, 2008 2AMDL, Inc. to Present at Maxim Group Growth Conference October 7, 2008 3Micromet Closes $40 Million Private Equity Placement 2Micromet Closes $40 Million Private Equity Placement 3Micromet Closes $40 Million Private Equity Placement 4
... It has been demonstrated that oxidative stress ... and cancer. Oxidative stress is the condition ... and physiological antioxidants exist leading to the ... response to oxidative stress is through several ...
... Human Serum-Single Donor • Human serum is ... found to be negative by a test ... Antibodies to Human Immunodeficiency Virus (Anti-HIV 1/2), ... Hepatitis B Surface Antigen (HbsAg) and Non-reactive ...
... Clean-up Micro Kit provides a fast and simple ... X-100 and other detergents from small samples of ... patented protein resin as an ion exchanger. Each ... of either acidic or basic protein.A complete kit ...
Compound(s) screened through any number of client selected assays. Client also selects number of concentrations and replicates....
Biology Products: