Numerical modeling of damage evolution of DP steels on the basis of X-ray tomography measurements

In order to couple the damage evolution and the stress state of DP steel grades, a new advanced GTN (Gurson-Tvergaard-Needleman) model was developed and implemented into a finite element code. This model is an extension of the original one. It takes into account the plastic anisotropy and the mixed (isotropic + kinematic) hardening of the matrix. Two different methods to compute the void volume fraction were developed and used within the constitutive equations. The first method is new and allows the accurate modeling of the observations of damage initiation and growth in DP steels measured using high-resolution X-ray absorption tomography ( [Bouaziz et al., 2008] and [Maire et al., 2008]). The second method is classic and assumes the additive decomposition of the total void volume fraction into a nucleation and a growth part. A parametric study is carried out to assess the effect of the kinematic hardening on some mechanical parameters such as the equivalent plastic strain, the triaxiality and the porosity. The numerical predictions are favorably compared to the experimental results.     

Interorganizational Dynamics and Characteristics of Critical Infrastructure Networks: The Study of Three Critical Infrastructures in the Greater Montreal Area

This study applies a strategic framework for assessing organizational and network resilience of 75 critical infrastructure (CI) players in the Greater Montreal area. It identifies the challenges to these CIs' resilience. Contingency analysis is used to describe the main tendencies regarding values, practices, rules and norms, communicational and decisional structures as well as the interdependencies and their institutional, normative and economic contexts. This article examines three well‐known CI networks: transportation, energy and telecommunication, comprising governmental, community and private‐sector organizations. To do so, we developed a survey instrument to collect data from hundreds of critical infrastructure managers. Our findings indicate discrepancies in internal and external resilience factors across organizational type, size and CI.     

Modulation of Lumen Formation by Microgeometrical Bioactive Cues and Migration Mode of Actin Machinery

How endothelial cells (ECs) express the particular filopodial or lamellipodial form of the actin machinery is critical to understanding EC functions such as angiogenesis and sprouting. It is not known how these mechanisms coordinately promote lumen formation of ECs. Here, adhesion molecules (RGD peptides) and inductor molecules (BMP‐2 mimetic peptides) are micropatterned onto polymer surfaces by a photolithographic technique to induce filopodial and lamellipodial migration modes. Firstly, the effects of peptide microgeometrical distribution on EC adhesion, orientation and morphogenesis are evaluated. Large micropatterns (100 μm) promote EC orientation without lumen formation, whereas small micropatterns (10–50 μm) elicit a collective cell organization and induce EC lumen formation, in the case of RGD peptides. Secondly, the correlation between EC actin machinery expression and EC self‐assembly into lumen formation is addressed. Only the filopodial migration mode (mimicked by RGD) but not lamellipodial migration mode (mimicked by BMP‐2) promotes EC lumen formation. This work gives a new concept for the design of biomaterials for tissue engineering and may provide new insight for angiogenesis inhibition on tumors.     

Casein micelles as a vehicle for iron fortification of foods

Casein micelles were loaded with iron to create a dispersible delivery format for insoluble iron by exposing milk at chilled temperatures to a high concentration of soluble iron (up to 20 mmol kg⁻¹ ferrous and ferric chloride). The loading was maximised by applying a pH-cycle to the fortified milk by means of carbonation. Upon acidification of fortified milk, no release of iron was observed, except at the highest concentration. Changes in the buffering capacity as a function of pH confirmed the formation of colloidal iron phosphates. Overall, most properties of the micelles did not change: hydration, protein distribution between soluble and colloidal phase remained constant, but zeta potential decreased slightly and curd formation upon renneting became much slower. The renneting behaviour could be improved by carbonation or storage at 30 °C for a day. Iron-fortified milk samples were stable under heating, except when fortification was achieved by means of 20 mmol kg⁻¹ ferric chloride. The most obvious difference of iron-fortified milk is its appearance: samples fortified with ferrous chloride were darker than control, whereas samples fortified with ferric chloride were more red/yellow.     

How does cognitive therapy prevent relapse in residual depression? Evidence from a controlled trial.

This study examined the cognitive mediation of relapse prevention by cognitive therapy (CT) in a trial of 158 patients with residual depression. Scores based on agreement with item content of 5 questionnaires of depression-related cognition provided no evidence for cognitive mediation. A measure of the form of response to those questionnaires, the number of times patients used extreme response categories ("totally agree" and "totally disagree"), showed significant and substantial prediction of relapse, differential response to CT, and conformity to mediational criteria. CT reduced relapse through reductions in absolutist, dichotomous thinking style. CT may prevent relapse by training patients to change the way that they process depression-related material rather than by changing belief in depressive thought content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of timber bending strength and in-member cross-sectional stiffness variation on the basis of local wood fibre orientation

Machine strength grading of structural timber is based upon relationships between so called indicating properties (IPs) and bending strength. However, such relationships applied on the market today are rather poor. In this paper, new IPs and a new grading method resulting in more precise strength predictions are presented. The local fibre orientation on face and edge surfaces of wooden boards was identified using high resolution laser scanning. In combination with knowledge regarding basic wood material properties for each investigated board, the grain angle information enabled a calculation of the variation of the local MOE in the longitudinal direction of the boards. By integration over cross-sections along the board, an edgewise bending stiffness profile and a longitudinal stiffness profile, respectively, were calculated. A new IP was defined as the lowest bending stiffness determined along the board. For a sample of 105 boards of Norway spruce of dimension 45 × 145 × 3,600 mm³, a coefficient of determination as high as 0.68–0.71 was achieved between this new IP and bending strength. For the same sample, the coefficient of determination between global MOE, based on the first longitudinal resonance frequency and the board density, and strength was only 0.59. Furthermore, it is shown that improved accuracy when determining the stiffness profiles of boards will lead to even better predictions of bending strength. The results thus motivate both an industrial implementation of the suggested method and further research aiming at more accurately determined board stiffness profiles.     

Aspects of reconfigurable and flexible fixtures

The design and manufacture of fixtures and other dedicated tooling for positioning of workpieces are among the major cost drivers in product industrialization. This has spurred research and commercial interest towards other fixturing solutions like reconfigurable fixtures, with the ability to be changed, or “reconfigured”, to suit different parts and products. When reconfiguring, the product interface not only has to be moved but moved to a desired position and orientation. Several different approaches have been used to move and position these devices, all with their own advantages and disadvantages. This article presents different methods used to position and reconfigure flexible fixture devices using a parallel kinematic device as a case. Discussing the different ways to reconfigure a flexible device, the article aims to arrange the techniques according to their key features.     

Reducing stigmatizing attitudes held by future health professionals: The person is the message.

This study represents a continuation of our efforts to identify a cost-effective, doable, practical intervention that, when added to the curriculum of future health professionals, results in the reduction of stigmatizing attitudes toward people living with mental illness. The authors reasoned that a personal presentation from a recovering person would, unlike previous educational efforts described, encompass the elements of personal relevance and inspiration and thus be effective. Measures of stigma, as well as of courtesy stigma, were used. The results support the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)