Role of anisotropic invariants in numerically modeling soft biological tissues as transversely isotropic hyperelastic materials: A comparative study

Shearing is induced in soft tissues in numerous physiological settings. The limited experimental data available suggest that a severe strain-stiffening effect occurs in the shear stress when soft biological tissues are subjected to simple shear in certain directions. This occurs at relatively small amounts of shear (when compared with the simple shear of rubbers). This effect is modelled within the framework of nonlinear elasticity by consideration of a class of incompressible anisotropic materials. Owing to the large stresses generated for relatively small amounts of shear, particular care must be exercised in order to maintain a homogeneous deformation state in the bulk of the specimen. The results obtained are relevant to the development of accurate shear test protocols for the determination of constitutive properties of soft tissues. It is also demonstrated that there is a fundamental ambiguity in determining the normal stresses in simple shear when soft tissues are modelled as incompressible hyperelastic materials owing to the arbitrary nature of the hydrostatic pressure term. Two physically well-motivated approaches to determining the pressure are presented here, and the resulting hydrostatic stresses are compared and contrasted. The possible generation of cavitational damage owing to critical hydrostatic stress levels is briefly discussed.

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Automated Estimation of Elastic Material Parameters of a Transversely Isotropic Material Using Asymmetric Indentation and Inverse Finite Element Analysis

Volume 3: Biomedical and Biotechnology Engineering ◽

10.1115/imece2015-51112 ◽

2015 ◽

Cited By ~ 3

Author(s):

Yuan Feng ◽

Chung-Hao Lee ◽

Lining Sun ◽

Ruth J. Okamoto ◽

Songbai Ji

Keyword(s):

Finite Element ◽

Soft Tissues ◽

Transverse Isotropy ◽

Transversely Isotropic ◽

Biological Tissues ◽

Fiber Reinforced ◽

Element Analysis ◽

Soft Biological Tissues ◽

Tissue Properties ◽

Brain White Matter

Anisotropy exists in many soft biological tissues. The most common anisotropy is transverse isotropy, which is typical for fiber-reinforced structures, such as the brain white matter, tendon and muscle. Although many methods have been proposed to determine tissue properties, techniques to characterize transversely isotropic materials remain limited. The goal of this study is to investigate the feasibility of asymmetric indentation coupled with numerical optimization based on inverse finite element (FE) simulation to characterize transversely isotropic soft biological tissues. The proposed approach combining indentation and optimization may provide a useful general framework to characterize a variety of fiber-reinforced soft tissues in the future.

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223 How can the role of N terminal pro B natriuretic peptide (NT-proBNP) be optimised in heart failure screening? A prospective observational comparative study

European Journal of Heart Failure Supplements ◽

10.1016/s1567-4215(04)90150-6 ◽

2004 ◽

Vol 3 (1) ◽

pp. 51 ◽

Cited By ~ 3

Author(s):

M ALBARJAS

Keyword(s):

Heart Failure ◽

Comparative Study ◽

Natriuretic Peptide

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Provision of Remedies for Violation of Economic, Social and Cultural Rights: A Comparative Study of the United Nations, Inter-American and African Human Rights Systems

African Journal of International and Comparative Law ◽

10.3366/ajicl.2020.0314 ◽

2020 ◽

Vol 28 (2) ◽

pp. 298-318

Author(s):

Roman Girma Teshome

Keyword(s):

Human Rights ◽

United Nations ◽

Comparative Study ◽

Economic Rights ◽

Regional Monitoring ◽

Cultural Rights ◽

The Past ◽

The United Nations ◽

To Receive

The effectiveness of human rights adjudicative procedures partly, if not most importantly, hinges upon the adequacy of the remedies they grant and the implementation of those remedies. This assertion also holds water with regard to the international and regional monitoring bodies established to receive individual complaints related to economic, social and cultural rights (hereinafter ‘ESC rights’ or ‘socio-economic rights’). Remedies can serve two major functions: they are meant, first, to rectify the pecuniary and non-pecuniary damage sustained by the particular victim, and second, to resolve systematic problems existing in the state machinery in order to ensure the non-repetition of the act. Hence, the role of remedies is not confined to correcting the past but also shaping the future by providing reforming measures a state has to undertake. The adequacy of remedies awarded by international and regional human rights bodies is also assessed based on these two benchmarks. The present article examines these issues in relation to individual complaint procedures that deal with the violation of ESC rights, with particular reference to the case laws of the three jurisdictions selected for this work, i.e. the United Nations, Inter-American and African Human Rights Systems.

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cAbdullah Yūsuf cAlī & Muhammad Asad: Two Approaches to the English Translation of the Qur'an

Journal of Qur anic Studies ◽

10.3366/jqs.2000.2.1.107 ◽

2000 ◽

Vol 2 (1) ◽

pp. 107-123 ◽

Cited By ~ 1

Author(s):

Muzaffar Iqbal

Keyword(s):

Twentieth Century ◽

Comparative Study ◽

Life Experiences ◽

Academic Career ◽

British India ◽

Human Understanding ◽

English Translations ◽

Political Milieu ◽

The Times

This article attempts to present a comparative study of the role of two twentieth-century English translations of the Qur'an: cAbdullah Yūsuf cAlī's The Meaning of the Glorious Qur'ān and Muḥammad Asad's The Message of the Qur'ān. No two men could have been more different in their background, social and political milieu and life experiences than Yūsuf cAlī and Asad. Yūsuf 'Alī was born and raised in British India and had a brilliant but traditional middle-class academic career. Asad traversed a vast cultural and geographical terrain: from a highly-disciplined childhood in Europe to the deserts of Arabia. Both men lived ‘intensely’ and with deep spiritual yearning. At some time in each of their lives they decided to embark upon the translation of the Qur'an. Their efforts have provided us with two incredibly rich monumental works, which both reflect their own unique approaches and the effects of the times and circumstances in which they lived. A comparative study of these two translations can provide rich insights into the exegesis and the phenomenon of human understanding of the divine text.

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