scholarly journals Strain Accommodations among Twin Variants in Ti and Mg

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 453
Author(s):  
Ping Zhou ◽  
Guo-Zhen Zhu
Keyword(s):  
Mechanical Property ◽  
Great Influence ◽  
Local Strain ◽  
Deformation Texture ◽  
Variant Selection ◽  
Slip Systems ◽  
Twinning Shear ◽  
Active Variant ◽  
Shed Light ◽  
Selection Of

The selection of twin variants has a great influence on deformation texture and mechanical property in hcp metals where slip systems are limited and twinning types are abundant during deformation. Local strain accommodations among twin variants are considered to shed light on variant selection rules in Ti and Mg alloys. Five kinds of strain accommodations are discussed in terms of different regions that are affected by the twinning shear of primary twin. These regions contain (I) the whole sample, (II) neighboring grain, (III) adjacent primary twin in neighboring grain, (IV) adjoining primary twin within the same parent grain, and (V) multi-generation of twinning inside the primary twin. For a potentially active variant, its operation needs not only relatively higher resolved shear stress but also easily accommodated strain by immediate vicinity. Many of the non-Schmid behaviors could be elucidated by local strain accommodations that variants with relatively higher SFs hard to be accommodated are absent, while those with relatively lower SFs but could be easily accommodated are present.

The Adult as Foe or Friend?: Childism in Guus Kuijer's Criticism and Fiction

2013 ◽  
Vol 6 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Vanessa Joosen
Keyword(s):  
Children's Literature ◽  
Children’S Literature ◽  
Age Groups ◽  
Children's Books ◽  
Children’S Books ◽  
Memorial Award ◽  
Adult Reader ◽  
Shed Light ◽  
Selection Of

Compared to the attention that children's literature scholars have paid to the construction of childhood in children's literature and the role of adults as authors, mediators and readers of children's books, few researchers have made a systematic study of adults as characters in children's books. This article analyses the construction of adulthood in a selection of texts by the Dutch author and Astrid Lindgren Memorial Award winner Guus Kuijer and connects them with Elisabeth Young-Bruehl's recent concept of ‘childism’ – a form of prejudice targeted against children. Whereas Kuijer published a severe critique of adulthood in Het geminachte kind [The despised child] (1980), in his literary works he explores a variety of positions that adults can take towards children, with varying degrees of childist features. Such a systematic and comparative analysis of the way grown-ups are characterised in children's texts helps to shed light on a didactic potential that materialises in different adult subject positions. After all, not only literary and artistic aspects of children's literature may be aimed at the adult reader (as well as the child), but also the didactic aspect of children's books can cross over between different age groups.

Tax evasion in the medical profession An Empirical Study in the General Tax Authority in Iraq

2019 ◽  
Vol 118 (11) ◽  
pp. 80-88
Author(s):  
Ramyar Rzgar Ahmed ◽  
Hawkar Qasim Birdawod ◽  
S. Rabiyathul Basariya
Keyword(s):  
Tax Evasion ◽  
Income Tax ◽  
Medical Profession ◽  
Great Influence ◽  
Tax Law ◽  
Degree Of Confidence ◽  
Medical Professions ◽  
Shed Light

The study dealt with tax evasion in the medical profession, where the problem was the existence of many cases of tax evasion, especially tax evasion in the income tax of medical professions. The aim of the study is to try to shed light on the phenomenon of tax evasion and the role of the tax authority in the development of controls and means that reduce the phenomenon of tax evasion. The most important results of the low level of tax awareness and lack of knowledge of the tax law and the unwillingness to read it and the sense of taxpayers unfairness of the tax all lead to an increase in cases of tax evasion and in suggested tightening control and follow-up on the offices of auditors, through the investigation and auditing The reports of certified accountants and the use of computers for this purpose in order to raise the degree of confidence in these reports and bring them closer to the required truth and coordination and cooperation with the Union of Accountants and Auditors and inform them about each case of violations of the auditors and accountants N because of its great influence in the rejection of the organization of the accounts and not to ratify fake accounts lead to show taxpayers accounts on a non-truth in order to tax evasion.

Veiling Esther, Unveiling Her Story

2018 ◽  
Author(s):  
Adam J. Silverstein
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Case Studies ◽  
Muslim World ◽  
Historical Narratives ◽  
Modern Times ◽  
Religious Background ◽  
Literary Context ◽  
Shed Light ◽  
Selection Of

This book examines the ways in which the biblical book of Esther was read, understood, and used in Muslim lands, from ancient to modern times. It zeroes-in on a selection of case studies, covering works from various periods and regions of the Muslim world, including the Qur’an, premodern historical chronicles and literary works, the writings of a nineteenth-century Shia feminist, a twentieth-century Iranian dictionary, and others. These case studies demonstrate that Muslim sources contain valuable materials on Esther, which shed light both on the Esther story itself and on the Muslim peoples and cultures that received it. The book argues that Muslim sources preserve important, pre-Islamic materials on Esther that have not survived elsewhere, some of which offer answers to ancient questions about Esther, such as the meaning of Haman’s epithet in the Greek versions of the story, the reason why Mordecai refused to prostrate himself before Haman, and the literary context of the “plot of the eunuchs” to kill the Persian king. Furthermore, throughout the book we will see how each author’s cultural and religious background influenced his or her understanding and retelling of the Esther story: In particular, it will be shown that Persian Muslims (and Jews) were often forced to reconcile or choose between the conflicting historical narratives provided by their religious and cultural heritages respectively.

A Mathematical Model for Competing Failure Modes in Strain Cycle Fatigue

2006 ◽  
Vol 129 (2) ◽  
pp. 293-303 ◽  
Author(s):  
Gerald T. Cashman
Keyword(s):  
Failure Modes ◽  
High Stress ◽  
Local Strain ◽  
Initiation Site ◽  
Weakest Link ◽  
Strain Relationship ◽  
Powder Metallurgy Alloy ◽  
Link Model ◽  
Cyclic Plastic Strain ◽  
Selection Of

Elevated temperature data for powder metallurgy alloy René 95 generated in vacuum are presented to demonstrate that the life differences observed between surface and internally initiated failures are due to an environmental effect. The transition in behavior from a mode at low stress dominated by internal initiations to a surface dominated mode at high stress is quantitatively described in terms of both a weakest-link model and a local strain relationship. A fatigue failure mechanism is provided that explains that the natural selection of initiation site is based upon the concept that the site displaying the highest local cyclic plastic strain is the location where fatigue initiates.

Strain compatibility effect on the variant selection of connected twins in magnesium

2015 ◽  
Vol 76 ◽  
pp. 71-76 ◽  
Author(s):  
Changfa Guo ◽  
Renlong Xin ◽  
Jianbin Xu ◽  
Bo Song ◽  
Qing Liu
Keyword(s):  
Compatibility Effect ◽  
Variant Selection ◽  
Strain Compatibility ◽  
Selection Of

A novel method for predicting variant selection of {101¯2} twins in pure hafnium

2021 ◽  
pp. 130738
Author(s):  
Yingdong Zhang ◽  
Geping Li ◽  
Fusen Yuan ◽  
Fuzhou Han ◽  
Muhammad Ali ◽  
...  
Keyword(s):  
Variant Selection ◽  
Novel Method ◽  
Selection Of

Application of a Genetic Algorithm to Concept Variant Selection

2006 ◽  
Author(s):  
Ryan S. Hutcheson ◽  
Robert L. Jordan ◽  
Robert B. Stone ◽  
Janis P. Terpenny ◽  
Xiaomeng Chang
Keyword(s):  
Genetic Algorithm ◽  
Product Development ◽  
Solution Space ◽  
Variant Selection ◽  
Functional Modeling ◽  
Detailed Design ◽  
Modeling Techniques ◽  
Break Even Point ◽  
Future Work ◽  
Selection Of

This paper outlines a framework for applying a genetic algorithm to the selection of component variants between the conceptual and detailed design stages of product development. A genetic algorithm (GA) is defined for the problem and an example is presented that demonstrates its application and usefulness. Functional modeling techniques are used to formulate the design problem and generate the chromosomes that are evaluated with the algorithm. In the presented example, suitable GA parameters and the break-even point where the GA surpassed an enumerated search of the same solution space were found. Recommend uses of the GA along with limitations of the method and future work are presented as well.

The Optimal Selection of Extrusion Parameters of As-Cast TC27 Titanium Alloy Based on Processing-Map

2017 ◽  
Vol 898 ◽  
pp. 1134-1139
Author(s):  
Xue Fei Li ◽  
Ai Xue Sha ◽  
Xu Huang ◽  
Li Jun Huang
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Processing Map ◽  
True Strain ◽  
Great Influence ◽  
Stable Condition ◽  
Dynamic Materials ◽  
Dynamic Materials Model ◽  
Selection Of

The hot deformation behavior of TC27 titanium alloy at the temperatures of 900-1150 °C and the strain rate of 0.01-10 s-1, the height reduction of 70%, was investigated in the isothermal compression test to identify the optimal extrusion parameters. The processing-map of TC27 titanium alloy was constructed based on dynamic materials model (DMM) and principle of Prasad*s instability. The conclusion shows that temperature and strain rate of deformation had a great influence on flow stress. At the beginning of deformation, the flow stress increased quickly with the augment of true strain and decreased slowly after flow stress reaching to the maximum value. Finally, flow stress tended to relatively stable condition. The flow stress decreased with the increase of temperature and increased with the increase of strain rate. The TC27 titanium alloy was sensitive to temperature and strain rate. Processing-map exhibited two peak efficiencies of power dissipation; one peak was 49% at 900°C/0.01 s-1, which dynamic recovery occured. The other peak was also 49% at 1050 °C /0.01s-1, which dynamic recrystallization occured in the domain. Besides, there were two instability areas in the processing-map which should be avoided during the extrusion. Therefore, in order to obtain the satisfactory properties, the parameters that 1050 °C and 0.01 s-1 were selected in the extrusion.

Variant selection of {10-12}-{10-12} double twins during the tensile deformation of an AZ31 Mg alloy

2017 ◽  
Vol 700 ◽  
pp. 226-233 ◽  
Author(s):  
Renlong Xin ◽  
Changfa Guo ◽  
John J. Jonas ◽  
Gang Chen ◽  
Qing Liu
Keyword(s):  
Tensile Deformation ◽  
Mg Alloy ◽  
Variant Selection ◽  
Az31 Mg Alloy ◽  
Selection Of

scholarly journals Deformation Texture Evolution in Flat Profile AlMgSi Extrusions: Experiments, FEM, and Crystal Plasticity Modeling

2021 ◽  
Vol 8 ◽  
Author(s):  
Tomas Manik ◽  
Knut Marthinsen ◽  
Kai Zhang ◽  
Arash Imani Aria ◽  
Bjørn Holmedal
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Crystal Plasticity ◽  
Texture Evolution ◽  
Rate Sensitivity ◽  
Deformation Texture ◽  
Fiber Texture ◽  
Electron Back Scatter Diffraction ◽  
Slip Systems ◽  
Flat Profile

In the present work, the deformation textures during flat profile extrusion from round billets of an AA6063 and an AA6082 aluminium alloy have been numerically modeled by coupling FEM flow simulations and crystal plasticity simulations and compared to experimentally measured textures obtained by electron back-scatter diffraction (EBSD). The AA6063 alloy was extruded at a relatively low temperature (350°C), while the AA6082 alloy, containing dispersoids that prevent recrystallization, was extruded at a higher temperature (500°C). Both alloys were water quenched at the exit of the die, to maintain the deformation texture after extrusion. In the center of the profiles, both alloys exhibit a conventional β-fiber texture and the Cube component, which was significantly stronger at the highest extrusion temperature. The classical full-constraint (FC)-Taylor and the Alamel grain cluster model were employed for the texture predictions. Both models were implemented using the regularized single crystal yield surface. This approach enables activation of any number and type of slip systems, as well as accounting for strain rate sensitivity, which are important at 350°C and 500°C. The strength of the nonoctahedral slips and the strain-rate sensitivity were varied by a global optimization algorithm. At 350°C, a good fit could be obtained both with the FC Taylor and the Alamel model, although the Alamel model clearly performs the best. However, even with rate sensitivity and nonoctahedral slip systems invoked, none of the models are capable of predicting the strong Cube component observed experimentally at 500°C.

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