creep at nanoscale! why??

I hope we could start a discussion here..for more see the following articles in JOM.

http://www.springerlink.com/content/y783g1r4q31nj275/

http://www.tms.org/pubs/journals/jom/jombyIssue.aspx?issue=JOM\2011\September

and

http://www.sciencedirect.com/science/article/pii/S0921509310008750

Using a new experimental setup have now proved that one could actually draw a thermal conductivity-strain relationship in the same way as stress-strain relation!

What remains to be seen is that whether this relationship is tensorial or not! Details are in the paper..

Correlating Microscale Thermal Conductivity of Heavily-Doped Silicon With Simultaneous Measurements of Stress," has been published online today, 20 October 2011, in Journal of Engineering Materials and Technology (Vol.133, Iss.4):

URL: http://link.aip.org/link/?JYT/133/041013
DOI: 10.1115/1.4004699

We all know most atomistic simulations in nanomechanics are performed on ideal materials that are not produced in laboratory and most experiments in nanomechanics are performed on materials that cannot be analyzed using atomistic simulations. Atomistic simulations indeed have a great capability in revealing a material's behavior with only constitutive law being used is that in the form of interatomic potential. The strain rate in atomistic simulations is of the order of 100000000 per sec which has not yet been achieved in any experiment or in a practical application.

Expected starting date: April 01, 2008 (if no issue with work VISA for international applicants) 

Salary: Negotiable

Duration: One year with a possibility of another year's extension subjected to availability of funds.

Reponsiblity: Work with two graduate students and one faculty in a core group focussed on experimental and simulation based bio-nanomechanical analyses of biomaterials. We are in need of a PhD with sound knowledge of fundementals related to the "keywords/tags" in the message to execute the research plans in a fast manner. We have in-house availability of the state of the art in computational as well as experimental resources.  Please email me at vikas.tomar@nd.edu with your CV to discuss more. Thanks.

A post-doc position is available at the University of Notre Dame in Aerospace and Mechanical Engineering. The project focuses on nanocomposite deformation modeling and performing corresponding experiments using primarily atomic force microscope and X-ray diffractometer. Initial position is for one-year and is extensible for another year contingent upon continued funding. The position offers attractive collaborative opportunities with national labs and material synthesis groups across different universities. Salary is negotiable. Please contact me (vikas.tomar@nd.edu) for more details. The tentative start date is May 01, 2008. Thank You.

Fracture in bone is a complex process that depends on the volume fraction (the relative fraction of bone tissue vs. void space), the architecture (the geometrical arrangement of the tissue), the mechanical properties of the bone tissue itself, and the applied loads. Theoretical approaches to the fracture of porous materials have been developed but their application to bone may be limited as they assume homogeneity of both the structure and the underlying material. The adaptation of the mechanical properties of bone to its loading history results in substantial heterogeneity of mechanical properties primarily due to the wide range of loads applied in the skeleton. Furthermore, bone diseases as well as pharmaceutical treatments for bone diseases can also affect the heterogeneity of material properties. All the above effects are intricately linked with bone micro-structure which incorporates collagen and mineral at the nanoscale in widely varying topological manners. With a wide ranging heterogeneity in length-scales of bone fracture it becomes imperative that fracture and failure analyses of bones are carried out at multiple lengthscales using a combination of modeling and experimental approaches. In this mini-symposium computational, experimental, and theoretical presentation of research on analyzing fracture of cortical as well as cancellous bone architectures are solicited. Presentations on computational and theoretical method development, experimental behavior characterization, and forming a link between theory and experiments are all strongly encouraged.

The mechanical, thermal, electrical, and chemical behaviors of nanostructured materials such as nanocrystalline materials, nanowires, nanofilms, and nanotubes have been increasingly studied with advanced simulation techniques such as the molecular dynamics (MD) method and its various variants including the Car-Parrinello method, Monte Carlo method, the tight-binding MD method, and first principle methods. However, quite often the analyses neglect the correlations among the different types of behaviors of the materials. Characterization of such correlations necessitates multiphysics approaches in modeling, simulation, and experiments. Examples include fatigue of nanocrystalline materials in corrosive environments, piezoelectric behavior of nanowires, and thermal-mechanical coupling of the behavior of nanobelts. With advances in the development of nanomaterials, there is a strong need to quantify material behavior accounting for multiphysics processes in a coupled manner. This symposium is intended to bring together researchers in multiphysics modeling, simulation and experiments of nanomaterials and nanostructured materials. The focus is primarily on a survey of the state of the art in molecular level multiphysics modeling, simulation, and experiments. Presentations on method development, behavior characterization, atomistic description, and continuum representation are all strongly encouraged.  (USNCCM website)