Unzipping bird feathers

The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments.

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Separating mechanism of dandelion (Taraxacum officinale) seed: Results from model analysis and separation force measurement

Wear ◽

10.1016/j.wear.2021.203846 ◽

2021 ◽

pp. 203846

Author(s):

Lixin Wang ◽

Shanshan Li ◽

Linlin Zhang

Keyword(s):

Force Measurement ◽

Taraxacum Officinale ◽

Model Analysis ◽

Separation Force

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Applying Simple Numerical Model to Predict Methane Emission from Landfill

Journal of Applied Sciences ◽

10.3923/jas.2007.1511.1515 ◽

2007 ◽

Vol 7 (11) ◽

pp. 1511-1515 ◽

Cited By ~ 6

Author(s):

Nader Shariatmad ◽

Mohammad Reza Sabour ◽

Hamidreza Kamalan ◽

Arash Mansouri ◽

Mostafa Abolfazlza

Keyword(s):

Numerical Model ◽

Methane Emission ◽

Simple Numerical Model

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A simple numerical model for the aeroelastic analysis of cable-stayed bridges

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/s0167-6105(99)00107-5 ◽

2000 ◽

Vol 84 (3) ◽

pp. 263-271 ◽

Cited By ~ 1

Author(s):

C.E.N. Mazzilli ◽

J.C. André ◽

M.E.S. Soares ◽

I.B. Ramos

Keyword(s):

Numerical Model ◽

Aeroelastic Analysis ◽

Simple Numerical Model ◽

Cable Stayed Bridges

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A Review of some Recent Radiation Fog Prediction Studies and the Results of Integrating a Simple Numerical Model to Predict Radiation Fog over Brunei

Pure and Applied Geophysics ◽

10.1007/s00024-003-8775-6 ◽

2003 ◽

Vol 160 (1-2) ◽

pp. 239-250 ◽

Cited By ~ 1

Author(s):

G.V. Rao ◽

J. O'Sullivan

Keyword(s):

Numerical Model ◽

Radiation Fog ◽

Fog Prediction ◽

Simple Numerical Model

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Development and use of a simple numerical model to quantify the impact of key photovoltaics system parameters on the levelized cost of electricity

2012 38th IEEE Photovoltaic Specialists Conference ◽

10.1109/pvsc.2012.6318200 ◽

2012 ◽

Cited By ~ 2

Author(s):

Moon Hee Kang ◽

Ajeet Rohatgi

Keyword(s):

Numerical Model ◽

Levelized Cost Of Electricity ◽

System Parameters ◽

Cost Of Electricity ◽

Levelized Cost ◽

The Impact ◽

Simple Numerical Model

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A new simple numerical model based on experimental scorch curve data fitting for the interpretation of sulphur vulcanization

Journal of Mathematical Chemistry ◽

10.1007/s10910-010-9689-z ◽

2010 ◽

Vol 48 (3) ◽

pp. 530-557 ◽

Cited By ~ 19

Author(s):

G. Milani ◽

F. Milani

Keyword(s):

Numerical Model ◽

Data Fitting ◽

Model Based ◽

Sulphur Vulcanization ◽

Simple Numerical Model

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An empirical statistical detection of non-ideal field distribution in a reverberation chamber confirmed by a simple numerical model based on image theory

annals of telecommunications - annales des télécommunications ◽

10.1007/s12243-011-0260-0 ◽

2011 ◽

Vol 66 (7-8) ◽

pp. 445-455 ◽

Cited By ~ 3

Author(s):

Emmanuel Amador ◽

Christophe Lemoine ◽

Philippe Besnier

Keyword(s):

Numerical Model ◽

Field Distribution ◽

Image Theory ◽

Reverberation Chamber ◽

Model Based ◽

Statistical Detection ◽

Simple Numerical Model

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INVESTIGATION OF STEEL FIBRE PULLOUT AND MODELING OF BRIDGING BEHAVIOUR IN SFRC

Engineering Structures and Technologies ◽

10.3846/2029882x.2012.729653 ◽

2012 ◽

Vol 4 (3) ◽

pp. 77-88

Author(s):

Ulvis Skadins ◽

Janis Brauns

Keyword(s):

Numerical Model ◽

Fibre Type ◽

Fracture Process ◽

Steel Fibre ◽

Test Results ◽

Average Force ◽

Pullout Tests ◽

Fibre Pullout ◽

Concrete Mix ◽

Pullout Behaviour

By adding fibres to concrete mix the objective is to bridge discrete cracks providing for some control to the fracture process and increase the fracture energy. Fibres become active mainly when cracking starts and deformation of the fibre occurs. Pullout tests with four types of fibres with different orientation, embedment lengths, and concrete strengths are performed to simulate the bridging process. Fibre pullout behaviour is analysed for relatively small slippage displacement to keep it close to real designing situations. The test results show significant effect of fibre type on pullout behaviour, nevertheless the effect is intangible on fibres inclined at 30 degrees or more. An effective displacement is introduced, derived from experimental force-slip curves, when fibre becomes involved in bridging. Based on the effective displacement and simplified average force-slip curves a numerical model is proposed to analyse the tensile stresses transferred by fibres crossing a crack.

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