A constitutive model of the deformation behaviour of twinning induced plasticity (TWIP) steel at different temperatures

The mechanical behaviour of Fe-18Mn-0.6C-1Al (wt%) TWIP steel was modelled in the temperature range from room temperature to 400°C. The proposed constitutive model was based on the Kocks-Mecking-Estrin (KME) model. The model parameters were determined using extensive experimental measurements of the physical parameters such as the dislocation mean free path and the volume fraction of twinned grains. More than 100 grains with a total area of ~300μm2 were examined at different strain levels over the entire stress-strain curve. Uniaxial tensile deformation of the TWIP steel was modelled for different deformation temperatures using a modelling approach which considers two distinct populations of grains: twinned and twin-free ones. A key point of the work was a meticulous experimental determination of the evolution of the volume fraction of twinned grains during uniaxial tensile deformation. This information was implemented in a phase-mixture model that yielded a very good agreement with the experimental tensile behaviour for the tested range of deformation temperatures. © 2014 Elsevier B.V.

Forming behaviour analysis and constitutive modelling of Ti-6Al-4V at room temperature.

 A constitutive model was proposed in this thesis and a promising approach for accurate prediction of forming behaviour of high strength titanium alloy sheet metal forming at room temperature is presented. Outcomes showed a potential solution of cold roll forming of this material for aerospace and automotive structural applications.

'Very inflated rhetoric polysyllables and so on': the public intellectual and jargon in the academy

The public intellectual, by their very definition, aims to reach a large sector of the public or publics. This requires proficiency, or at least the capacity to communicate in a variety of forms. As a large proportion of the public, to which the public intellectual appeals, is an online or cyber public, the importance of blogs in a computer-literate public cannot be under-estimated. The immediacy of the blog and the way in which an online presence facilitates immediate communication between the public and the public intellectual through the posting of comments online allow for a broad recognition of the intellectual in the public arena. My arguments will hinge on my interviews with contemporary American public intellectuals (Noam Chomsky, Howard Zinn, Todd Gitlin, Camille Paglia and Stephen Greenblatt) and their views on communication in a society experiencing a decline in the publication of print media.

Constitutive analysis of hot deformation behavior of a Ti6Al4V alloy using physical based model

The effect of deformation parameters on the flow behavior of a Ti6Al4V alloy has been studied to understand the deformation mechanisms during hot compression. Cylindrical samples with partially equiaxed grains were deformed in the α+β phase region at different thermo-mechanical conditions. To develop components with tailored properties, the physically based Estrin and Mecking (EM) model for the work hardening/dynamic recovery combined with the Avrami equation for dynamic recrystallization was used to predict the flow stress at varying process conditions. The EM model revealed good predictability up to the peak strain, however, at strain rates below 0.01s^-1, a higher B value was observed due to the reduced density of dislocation tangles. In contrast, the flow softening model revealed higher value of constants a and b at high strain rates due to the reduction in the volume fraction of dynamic recrystallization and larger peak strain. The predicted flow stress using the combined EM+Avrami model revealed good agreement with the measured flow stress resulted in very low average absolute relative error value. The microstructural analysis of the samples suggests the formation of coarse equiaxed grains together with the increased β phase fraction at low strain rate leads to a higher flow softening.

Mental health and human rights: the MI Principles - turning rhetoric into action

The purpose of this paper is to describe and explain General Assembly Resolution 46/119 United Nations Principles for the Protection of Persons with Mental Illness and for the Improvement for Mental Health Care and situate them in the current examination of mental health and human rights issues. The paper will provide country examples of human rights standards in mental healthcare, will exemplify some of the failures to use the MI Principles and comment on why this has occurred. The paper will also discuss the 'Principles to Respect': Initiative on Mental Health and Human Rights, a practical strategy to address the human rights standards of persons with mental illness.

Constitutive overexpression of the OsNAS gene family reveals single-gene strategies for effective iron- and zinc-biofortification of rice endosperm

Background
Rice is the primary source of food for billions of people in developing countries, yet the commonly consumed polished grain contains insufficient levels of the key micronutrients iron (Fe), zinc (Zn) and Vitamin A to meet daily dietary requirements. Experts estimate that a rice-based diet should contain 14.5 µg g−1 Fe in endosperm, the main constituent of polished grain, but breeding programs have failed to achieve even half of that value. Transgenic efforts to increase the Fe concentration of rice endosperm include expression of ferritin genes, nicotianamine synthase genes (NAS) or ferritin in conjunction with NAS genes, with results ranging from two-fold increases via single-gene approaches to six-fold increases via multi-gene approaches, yet no approach has reported 14.5 µg g−1 Fe in endosperm.

Methodology/Principal Findings
Three populations of rice were generated to constitutively overexpress OsNAS1, OsNAS2 or OsNAS3, respectively. Nicotianamine, Fe and Zn concentrations were significantly increased in unpolished grain of all three of the overexpression populations, relative to controls, with the highest concentrations in the OsNAS2 and OsNAS3 overexpression populations. Selected lines from each population had at least 10 µg g−1 Fe in polished grain and two OsNAS2 overexpression lines had 14 and 19 µg g−1 Fe in polished grain, representing up to four-fold increases in Fe concentration. Two-fold increases of Zn concentration were also observed in the OsNAS2 population. Synchrotron X-ray fluorescence spectroscopy demonstrated that OsNAS2 overexpression leads to significant enrichment of Fe and Zn in phosphorus-free regions of rice endosperm.

Conclusions
The OsNAS genes, particularly OsNAS2, show enormous potential for Fe and Zn biofortification of rice endosperm. The results demonstrate that rice cultivars overexpressing single rice OsNAS genes could provide a sustainable and genetically simple solution to Fe and Zn deficiency disorders affecting billions of people throughout the world.

Wavelet-Galerkin method for one-dimensional elastoplasticity and damage problems: Constitutive modeling and computational aspects

This work presents an analysis of the wavelet-Galerkin method for one-dimensional elastoplastic-damage problems. Time-stepping algorithm for non-linear dynamics is presented. Numerical treatment of the constitutive models is developed by the use of return-mapping algorithm. For spacial discretization we can use wavelet-Galerkin method instead of standard finite element method. This approach allows to locate singularities. The discrete formulation developed can be applied to the simulation of one-dimensional problems for elastic-plastic-damage models. (C) 2007 Elsevier B.V. All rights reserved.