scholarly journals Energy dissipation and recovery in a simple model with reversible cross-links

2015 ◽  
Vol 91 (3) ◽  
Author(s):  
S. Soran Nabavi ◽  
Peter Fratzl ◽  
Markus A. Hartmann
Keyword(s):  
Energy Dissipation ◽  
Simple Model ◽  
Cross Links

scholarly journals Elasticity and energy dissipation in the double network hydrogel adhesive of the slug Arion subfuscus

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190201 ◽  
Author(s):  
T.-M. Fung ◽  
C. Gallego Lazo ◽  
A. M. Smith
Keyword(s):  
Energy Dissipation ◽  
Time Course ◽  
Tensile Tests ◽  
Cyclic Stress ◽  
Mechanical Tests ◽  
Double Network ◽  
Ph Values ◽  
Arion Subfuscus ◽  
Synthetic Adhesives ◽  
Cross Links

The slug Arion subfuscus produces a mucus-based defensive secretion that is remarkably tough. This glue appears to be a double network hydrogel, gaining its toughness through the synergistic actions of two networks of polymers, a relatively stiff network and a relatively deformable network. The double network mechanism has great potential to guide the development of synthetic adhesives. Mechanical tests were performed to analyse key predictions of the mechanism. Stress relaxation tests and tensile tests support the presence of stable cross-links. Cyclic stress–strain tests demonstrate that the glue dissipates a great deal of energy through the failure of these cross-links as sacrificial bonds. Energy dissipation by failure of sacrificial bonds rather than viscous processes is supported by the minimal effect of the time course of the experiments on the measured properties. These sacrificial bonds appear able to reform within minutes after failure. Finally, the glue's stiffness decreases at pH values below 5.5, whereas magnesium and calcium rapidly dissociate from the glue at all pH values tested. Thus, these ions may not be the primary cross-linkers generating the glue's stiffness. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

scholarly journals Dynamical Magnetic Energy Release of Current Loops in the Corona: Effects of Toroidal Forces

1989 ◽  
Vol 104 (2) ◽  
pp. 293-296
Author(s):  
James Chen
Keyword(s):  
Energy Dissipation ◽  
Simple Model ◽  
Range Of Motion ◽  
Energy Release ◽  
Magnetic Energy ◽  
Current Loop ◽  
Magnetic Current ◽  
Wide Range ◽  
A Current ◽  
Magnetic Energy Release

AbstractWe discuss a mechanism whereby a current loop embedded in plasmas such as the solar and stellar coronae can dissipate magnetic energy without resistive effects or reconnection. This mechanism arises from the motion of magnetic/current structures driven by “toroidal forces”. Using a simple model loop, we show that it can exhibit a wide range of motion with correspondingly wide range of magnetic energy dissipation rates. For example, a loop with ~20G can attain expansion velocities of ~1200km s–1 under solar coronal conditions, dissipating ~1032erg in a few tens of minutes.

scholarly journals Dissipation In Quantum Mechanics

1966 ◽  
Vol 19 (5) ◽  
pp. 587
Keyword(s):  
Quantum Mechanics ◽  
Energy Dissipation ◽  
Simple Model ◽  
Electromagnetic Mode ◽  
Weakly Coupled

The energy dissipation of an electromagnetic mode, weakly coupled to a solid, is derived for a simple model. The result differs in significant detail from that previously obtained by a different method. Reasons for the discrepancy are given, with referenc

Applicability of a particularly simple model to nonlinear elasticity of slide-ring gels with movable cross-links as revealed by unequal biaxial deformation

2014 ◽  
Vol 141 (13) ◽  
pp. 134906 ◽  
Author(s):  
Yuuki Kondo ◽  
Kenji Urayama ◽  
Masatoshi Kidowaki ◽  
Koichi Mayumi ◽  
Toshikazu Takigawa ◽  
...  
Keyword(s):  
Simple Model ◽  
Nonlinear Elasticity ◽  
Biaxial Deformation ◽  
Cross Links

scholarly journals Energy Absorbed by Composite Conical Structures in Axial Crushing

2014 ◽  
Vol 23 (1) ◽  
pp. 096369351402300 ◽  
Author(s):  
Simonetta Boria ◽  
Silvia Pettinari
Keyword(s):  
Energy Dissipation ◽  
Simple Model ◽  
Kinetic Energy ◽  
Energy Absorption ◽  
Analytical Approach ◽  
Method Comparison ◽  
Total Displacement ◽  
Thin Walled ◽  
Theory And Experiments ◽  
Conical Structures

Recently crashworthiness trend is the use of thin-walled composite impact attenuators in specific vehicle zones, ensuring kinetic energy absorption. The present paper addresses the composite conical structures design using an analytical approach for predicting energy dissipation in a controlled way. A balance of internal energies involved in the absorption and external force yields the average crush load and the total displacement through a numerical method. Comparison between theory and experiments shows the efficiency of the proposed relatively simple model for predicting energy absorption of axially collapsing composite shells.

Derailment of Trains

1994 ◽  
Vol 22 (3) ◽  
pp. 165-176 ◽  
Author(s):  
J. Roorda ◽  
B. Gracie
Keyword(s):  
Energy Dissipation ◽  
Simple Model ◽  
Dynamic Process ◽  
Model Parameters ◽  
Complex Dynamic ◽  
Friction Forces

A simple model of train derailments reduces a complex dynamic process to a recursive series of statics and geometry calculations accompanied by computation of energy dissipation by ground friction forces. A calibration of the model parameters ensures a good fit to reality. Some derailment characteristics can be predicted.

Study of eukaryotic flagellar components by cryo-electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 98-101
Author(s):  
John M. Murray ◽  
Rob Ward
Keyword(s):  
Electron Microscopy ◽  
Primary Motion ◽  
Cryo Electron Microscopy ◽  
Cross Links ◽  
Cilia And Flagella

The eukaryotic flagellum is constructed from 11 parallel tubular elements arranged as 9 peripheral fibers (doublet microtubules) and 2 central fibers (singlet microtubules). The primary motion generating component has been found to be arranged as axially periodic “arms” bridging the adjacent doublets. The dynein, comprising the arms, has been isolated and characterized from several different cilia and flagella. Various radial and azimuthal cross-links stabilize the axially aligned microtubules, and probably play some role in controlling the form of the flagella beat cycle.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

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