Search results for " DAMAGE"

Neurocognitive Developmental Disorders: A Real Challenge for Developmental Neuropsychology

2002

Ritz Model for Damage Analysis in Variable Angle Tow Composite Plates

2022

In this work, a Ritz method is developed for progressive damage analysis of multilayered variable angle tow (VAT) composite plates under geometrically non-linear strains. The proposed model adopts a first order shear deformation theory and considers geometric non-linearities through the von Karman assumptions. A meso-modelling approach based on Continuum Damage Mechanics is adopted for analysing the initiation and evolution of damage. The onset of damage is predicted using the Hashin’s criteria. Four damage indices are defined and computed for expressing the degradation of the mechanical properties of the material, both for fibers and matrix under either tension and compression loading. A s…

Interlaminar decohesion and inner-layer damage in composite structures

2008

Genotoxicity investigations on nanomaterials: methods, preparation and characterization of test material, potential artifacts and limitations--many q…

2008

Nanomaterials display novel properties to which most toxicologists have not consciously been exposed before the advent of their practical use. The same properties, small size and particular shape, large surface area and surface activity, which make nanomaterials attractive in many applications, may contribute to their toxicological profile. This review describes what is known about genotoxicity investigations on nanomaterials published in the openly available scientific literature to-date. The most frequently used test was the Comet assay: 19 studies, 14 with positive outcome. The second most frequently used test was the micronucleus test: 14 studies, 12 of them with positive outcome. The A…

A hybrid virtual–boundary element formulation for heterogeneous materials

2021

Abstract In this work, a hybrid formulation based on the conjoined use of the recently developed Virtual Element Method (VEM) and the Boundary Element Method (BEM) is proposed for the effective computational analysis of multi-region domains, representative of heterogeneous materials. VEM has been recently developed as a generalisation of the Finite Element Method (FEM) and it allows the straightforward employment of elements of general polygonal shape, maintaining a high level of accuracy. For its inherent features, it allows the use of meshes of general topology, including non-convex elements. On the other hand, BEM is an effective technique for the numerical solution of sets of boundary i…

Computer modelling of radiation damage in cation sublattice of corundum

1998

Results of quantum chemical computer simulations of close Frenkel defects in corundum crystals are presented and discussed. The conclusion is drawn that the energy barrier for a back recombination up to fourth nearest neighbours is less than 0.3 eV, i.e. such pairs should be unstable at temperatures above 40 K.

Congenital reduction in number of nephrons accelerates renal damage, and limits proximal tubular growth response to release of neonatal partial urete…

2012

Aim: to analyze the evolution of the response to persistent partial ureteral obstruction (PUO) and obstruction/release (PUO/Rel) in mice with 50% reduction in the number of nephrons from 21 days of age (time of weaning) to 42 days of age (adulthood). Methods: C57/BL6 wild-type (WT) and mice with oligosyndactylism and 50% reduction of nephron number (Os/+), were subjected to sham operation or PUO in the first 2 days of life. Additional mice underwent release of obstruction at 7 days (PUO-Rel). The study was performed in kidneys harvested at 21 and 42 days. Using histomorphometry, glomerular area (GA) was determined by PAS staining, and fractional proximal tubular (PT) mass and intact glomeru…

A symmetric nonlocal damage theory

2003

The paper presents a thermodynamically consistent formulation for nonlocal damage models. Nonlocal models have been recognized as a theoretically clean and computationally efficient approach to overcome the shortcomings arising in continuum media with softening. The main features of the presented formulation are: (i) relations derived by the free energy potential fully complying with nonlocal thermodynamic principles; (ii) nonlocal integral operator which is self-adjoint at every point of the solid, including zones near to the solid's boundary; (iii) capacity of regularizing the softening ill-posed continuum problem, restoring a meaningful nonlocal boundary value problem. In the present app…

A review of colour center and nanostructure creation in LiF under heavy ion irradiation

2015

A study of radiation damage in LiF crystals under irradiation with MeV–GeV energy ions, from 12C to 238U, at temperatures varying from 8 to 300 K, depending on the ion energy, energy loss and irradiation temperature, is presented. For light ions (12C, 14N) at low fluences, it is mainly color centers that are created. Increasing the fluence leads to the overlapping of tracks and the creation of more complex color centers, defect aggregates and dislocations. For ions with an energy loss above a threshold value (dE/dx = 10 keV nm−1) the tracks exhibit a central core damage region with a radius of 1–2 nm, surrounded by an extended halo which mainly contains single color centers. In this case, i…

Familial hypercholesterolæmia in children and adolescents: Gaining decades of life by optimizing detection and treatment

2015

Contains fulltext : 155263.pdf (Publisher’s version ) (Open Access) Familial hypercholesterolaemia (FH) is a common genetic cause of premature coronary heart disease (CHD). Globally, one baby is born with FH every minute. If diagnosed and treated early in childhood, individuals with FH can have normal life expectancy. This consensus paper aims to improve awareness of the need for early detection and management of FH children. Familial hypercholesterolaemia is diagnosed either on phenotypic criteria, i.e. an elevated low-density lipoprotein cholesterol (LDL-C) level plus a family history of elevated LDL-C, premature coronary artery disease and/or genetic diagnosis, or positive genetic testin…