Numerical study of an arcan tensile compression shear test in dynamic: application to bonded joints

This paper presents a numerical study of the Arcan TCS testing device under dynamic conditions. This test is commonly used to characterize the mechanical behavior of bonded joints subjected to combined quasi-static loadings. In this study, the question of its extensibility to dynamic loadings by the use of an impactor guided in a drop tower is investigated. A dedicated finite element model is built under the plane stress assumption. Stress distributions in the adhesive are analysed trought time ans space for several configurations

Photochromism of photoenolizable ketones in quinoline and 1,8-naphthyridine series studied by time-resolved absorption spectroscopy

For the two photochromic molecules, 3-benzoyl-2-benzyl-1-methyl-1H-quinolin-4-one (QC1) and 3-benzoyl-1,2-dibenzyl-1H-1,8-naphthyridin-4-one (QC18a) as well as the nonphotochromic 3-benzoyl-1-benzyl-2-methyl-1H-1,8-naphthyridin-4-one (QC18b), the full photochemical mechanism, which is based on the photoenolization process, has been elucidated using stationary and time-resolved spectroscopy techniques. After photoexcitation, the S1(n,*)-T1(n,*) ISC process involving the exocyclic carbonyl chromophore is demonstrated to occur. Subsequently, -hydrogen transfer proceeds very rapidly to give rise to the triplet photoenol with a probable 1,4-biradical structure. For all three molecules, the biradical is clearly detected and proved quantitatively to be the direct precursor of the colored form (photochromic compounds) or ground state starting material (nonphotochromic compound). Solvent effects for the three molecules studied may suggest the existence of intramolecular hydrogen bonding in both biradical and colored form species. Structural effects on the -hydrogen transfer rate and biradical decay are related to the photochromic performances

Assessment of executive functioning in children and young adults treated for frontal lobe tumours using ecologically valid tests

There is a lack of studies assessing executive functions (EF) using ecologically valid tests in children with frontal lobe lesions. This study aimed to (1) evaluate EF in children, adolescents and young adults treated for childhood frontal lobe tumours, (2) identify factors influencing performance, such as age at diagnosis or type of treatment, and (3) examine correlations between intellectual ability and classical and ecological tests of EF. Twenty-one patients, aged 8–27 years, treated for a childhood benign or malignant frontal lobe tumour, and 42 healthy controls (matched for gender, age and socio-economic status) were assessed using classical tests of EF, and the BADS-C ecological battery. Patients also underwent assessment of intellectual ability and parent and teacher ratings of the BRIEF questionnaire. IQ scores ranged from 45 to 125 (mean FSIQ = 84) and were lower in case of epilepsy, hydrocephalus and lower parental education. Patients displayed deficits in most, but not all measures of EF. Most classical and ecological measures of EF were strongly correlated to IQ. This study confirms the frequency of EF deficits in this population; it also highlights the utility of ecological measures of EF and some limitations of classical tests of EF in children