scholarly journals Fundamental mechanics of tooth fracture and wear: implications for humans and other primates

2021 ◽  
Vol 11 (5) ◽  
pp. 20200070
Author(s):  
Oscar Borrero-Lopez ◽  
Fernando Rodriguez-Rojas ◽  
Paul J. Constantino ◽  
Brian R. Lawn

Until recently, there had been little attempt in the literature to identify and quantify the underlying mechanics of tooth durability in terms of materials engineering concepts. In humans and most mammals, teeth must endure a lifetime of sustained occlusal mastication—they have to resist fracture and wear. It is well documented that teeth are resilient, but what are the unique features that make this possible? The present article surveys recent materials engineering research aimed at addressing this fundamental question. Elements that determine the mechanics and micromechanics of tooth fracture and wear are analysed: at the macrostructural level, the geometry of the enamel shell and cuspal configuration; and at the microstructural level, interfacial weakness and property gradients. Inferences concerning dietary history in relation to evolutionary pressures are discussed.

Author(s):  
P. J. Webster ◽  
Z. Chen ◽  
D. J. Hughes ◽  
A. Steuwer ◽  
B. Malard ◽  
...  

Large Central Scientific Facilities such as the ESRF (the European Synchrotron Radiation Facility) and ILL (the European centre for neutron research), were set up to provide scientists with the advanced facilities they need to exploit neutron and synchrotron X-ray beams for scientific research. Engineers also conduct research at these Facilities, but this is less common as most practicing engineers generally have little or no knowledge of neutron or X-ray scattering, or of their considerable potential for engineering research, model validation, material development and for fatigue and failure analysis. FaME38 is the new joint support Facility for Materials Engineering, located at ILL-ESRF, set up to encourage and to facilitate engineering research by engineers at these facilities. It provides a technical and knowledge centre, a materials support laboratory, and the additional equipment and resources that academic and industrial engineers need for materials engineering research to become practicable, efficient and routine. It enables engineers to add the most advanced scientific diffraction and imaging facilities to their portfolio of diagnostic tools. These include non-destructive internal and through-surface strain scanning, phase analysis, radiography and tomography of engineering components. Synchrotron X-ray and neutron diffraction strain mapping is particularly suited for the rigorous experimental, non-destructive, validation of Finite Element and other computer model codes used to predict residual stress fields that are critical to the performance and lifetimes of engineering components. This paper discusses the FaME38 facility and demonstrates its utility in gaining fundamental insight into mechanical engineering problems through examples, including studies of railway rails, welds and peened surfaces that demonstrate the potential of neutron of synchrotron X-ray strain scanning for the determination of residual stress fields in a variety of engineering materials and critical components.


2017 ◽  
Vol 53 (2) ◽  
pp. 243-264
Author(s):  
Jonas Svensson

Recent years have witnessed several examples of desecrations of copies of the Qur’an as a display of non-Muslim hostility against Muslims. The present article attempts to answer a fundamental question relating to this phenomenon: how do desecrators know what acts directed at the Qur’an are likely to offend Muslims? The suggestion put forward is that desecration is an act that can be understood across cultural and religious boundaries because it is based on shared, intuitive knowledge of what the sacredness of an object entails. This knowledge, in turn, rests upon certain mental operations involved in the process of sacralisation: i.e. when things are ‘set apart and forbidden’. When the mental processes of psychological essentialism and conceptual blending are combined, it results in a partial personification of the sacred object, providing inferences concerning which acts count as desecrations, i.e. acts that, had they been directed at a person, would cause harm, whether physical or psychological.


2016 ◽  
Vol 746 ◽  
pp. 012009 ◽  
Author(s):  
J Fenske ◽  
M Rouijaa ◽  
J Šaroun ◽  
R Kampmann ◽  
P Staron ◽  
...  

2003 ◽  
Vol 34 (4) ◽  
pp. 219-226 ◽  
Author(s):  
Bart Duriez ◽  
Claudia Appel ◽  
Dirk Hutsebaut

Abstract: Recently, Duriez, Fontaine and Hutsebaut (2000) and Fontaine, Duriez, Luyten and Hutsebaut (2003) constructed the Post-Critical Belief Scale in order to measure the two religiosity dimensions along which Wulff (1991 , 1997 ) summarized the various possible approaches to religion: Exclusion vs. Inclusion of Transcendence and Literal vs. Symbolic. In the present article, the German version of this scale is presented. Results obtained in a heterogeneous German sample (N = 216) suggest that the internal structure of the German version fits the internal structure of the original Dutch version. Moreover, the observed relation between the Literal vs. Symbolic dimension and racism, which was in line with previous studies ( Duriez, in press ), supports the external validity of the German version.


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