research

Mechanics of microtubule buckling in living cells

Submitted by Teng Li on Thu, 03/06/2008 - 16:29

As the most rigid cytoskeletal filaments, microtubules bear compressive forces in living cells, balancing the tensile forces within the cytoskeleton to maintain the cell shape. It is often observed that, in living cells, microtubules under compression severely buckle into short wavelengths. By contrast, when compressed, isolated microtubules in vitro buckle into single long-wavelength arcs. The critical buckling force of the microtubules in vitro is two orders of magnitude lower than that of the microtubules in living cells.

iSIGHT and modeFRONTIER

Submitted by tianfa on Thu, 03/06/2008 - 06:32

research

hi all.

i'm not a researcher like allof you, i'm just a final year EEE student. i am seeking help for comparisons between iSIGHT and modeFRONTIER. if anybody can help i'ld be most grateful.

thank you and good day.

Multiwalled carbon nanotubes: the thicker, the softer

Submitted by Marino Arroyo on Sun, 03/02/2008 - 22:13

I. Arias and M. Arroyo, Size-Dependent Nonlinear Elastic Scaling of Multiwalled Carbon Nanotubes, Phys. Rev. Lett. 100, 085503 (2008).

Application of FEM in geotechnics

Submitted by Guest on Sat, 03/01/2008 - 23:54

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finite element methods

I am looking for specific research topics in applications of FEM in geotechnical engineering. It is just to gather some topics so as to pick the interesting one for my PHD.Anybody willing to share something on this? You can suggest any topic and of course few details will be helpful.

Journal Club Theme of March 1: Measuring Cellular Tractions

Submitted by Vesna Damljanovic on Sat, 03/01/2008 - 04:52

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inverse problems

cellular tractions

Cell tractions are the outcome of the complex process of cytoskeletal force generation that cell uses to maintain structural stability, to sense the physical environment and to propel itself. We are only now beginning to understand the process of cytoskeletal force generation, and we cannot yet say much about the losses in transmission through focal adhesion/integrin complexes (attachment ‘islands’ at the cell-substrate interface), but we can definitely measure the tractions that result from cytoskeletal force generation. The mechanics behind the measurement method might be of interest to the wider audience of iMechanica, as it involves an interesting inverse problem and different solution methods that have incited lively discussions in past years.

Predictive modeling schemes for wear in tribometers

Submitted by vh on Sat, 03/01/2008 - 01:07

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Study of wear in complex micro-mechanical components is often accomplished experimentally using a pin-

on-disc and twin-disc tribometer. The present paper proposes an approach that involves a computationally

efficient incremental implementation of Archard’s wear model on the global scale for modeling sliding and

slipping wear in such experiments. It will be shown that this fast simplistic numerical tool can be used to

identify the wear coefficient from pin-on-disc experimental data and also predict the wear depths within a

Not just another pillar compression paper

Submitted by Yanfei Gao on Fri, 02/29/2008 - 21:18

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We show that it is possible to distinguish between homogeneous and heterogeneous dislocation nucleation on the basis of differences in experimentally measured theoretical strengths. From nanoindentation tests, the critical shear stress for dislocation nucleation in two different Mo-alloy single crystals (Mo-3Nb and Mo-10Al-4Ni) is found to be ~1/8 of the shear modulus. The corresponding stress in uniaxially compressed Mo-10Al-4Ni micropillars is ~1/26 of the shear modulus.