A superparamagnetic nanoparticle (SPN) is a nanometre-sized piece of a material that would, in bulk, be a permanent magnet. In the SPN the individual atomic spins are aligned via Pauli effects into a single giant moment that has easy orientations set by shape or magnetocrystalline anisotropy. Above a size-dependent blocking temperature Tb(V, τobs) , thermal fluctuations destroy the average mome...

Force-based atomistic-continuum hybrid methods are the only known pointwise consistent methods for coupling a general atomistic model to a finite element continuum model. For this reason, and due to their algorithmic simplicity, force-based coupling methods have become a popular class of atomistic-continuum hybrid models as well as other types of multiphysics models. However, the recently disco...

Residual force enhancement has been observed following active stretch of skeletal muscles and single fibres. However, there has been intense debate whether force enhancement is a sarcomeric property, or is associated with sarcomere length instability and the associated development of non-uniformities. Here, we studied force enhancement for the first time in isolated myofibrils (n=18) that, owin...

Muscle residual force enhancement has been observed in different muscle preparations for more than half a century. Nonetheless, its mechanism remains unclear; to date, there are three generally accepted hypotheses: 1) sarcomere length non-uniformity, 2) engagement of passive elements, and 3) an increased number of cross-bridges. The first hypothesis uses sarcomere non-homogeneity and instabilit...

Residual stress present in coupons used for fracture testing will influence the experimental determination of fracture toughness. Triaxial residual stress (e.g., due to welding) can alter both the driving force for fracture and the crack-tip constraint at a specified load, so that the apparent toughness of a coupon depends on the residual stress present. In this paper, we employ a micromechanic...

Herzog W. Mechanisms of enhanced force production in lengthening (eccentric) muscle contractions. J Appl Physiol 116: 1407–1417, 2014. First published February 21, 2013; doi:10.1152/japplphysiol.00069.2013.—In contrast to isometric and shortening contractions, many observations made on actively lengthening muscles cannot be readily explained with the sliding filament and cross-bridge theory. Sp...

Biological membranes have a central role in mediating the organization of membrane-curving proteins, a dynamic process that has proven to be challenging to probe experimentally. Using atomic force microscopy, we capture the hierarchically organized assemblies of Bin/amphiphysin/Rvs (BAR) proteins on supported lipid membranes. Their structure reveals distinct long linear aggregates of proteins, ...

all the producing and assembling processes exert residual stress on the pieces that may lead to structural failure. therefore, calculating the residual stress in such structures has been common in recent years. in this article, distribution of temperature and residual stress resulting from arc welding in three-pass butt joint in p91 austenitic stainless steel pipes is calculated and estimated u...