Search results for "wt"

Thermodynamics and continuum fracture mechanics for nonlocal-elastic plastic materials

2002

Nonlocal elasticity is used as an improved elasticity model which engenders no crack-tip stress singularities and thus makes applicable the classical stress-based failure criteria. Considering nonlocal-elastic plastic materials exposed to softening by particle decohesion in a process surface and to subsequent surface separation by fracture, fracture mechanics is addressed within the framework of irreversible internal-variable thermodynamics in the hypothesis of small strains and arbitrary (but sufficiently regular) fracture surface (crack surface plus process surface). The state equations and the energy dissipation densities are derived for the bulk material and for the process surface, for…

Crack growth analysis at adhesive–adherent interface in bonded joints under mixed mode I/II

2008

The propagation of an interface crack subjected to mixed mode I/II was investigated for two 2024-T351 aluminum thin layers joined by means of DP760 epoxy adhesive produced by 3M©. On the basis of beam theory, an analytical expression for computing the energy release rate is presented for the mixed-mode end loaded split (MMELS) test. The analytical strain energy release rate was compared by finite element (FE) analysis using the virtual crack closure technique (VCCT). Several fatigue crack growth tests were carried out in a plane bending machine to compare the experimental energy release rates to those of the analytical and FE solutions. Experimental results showed the relationship between t…

Genetic and morphometric variation of Mediterranean hake, Merluccius merluccius, in the Strait of Sicily (Central Mediterranean)

2004

Allozyme, morphometric and growth analyses were applied to samples collected in the Strait of Sicily (central Mediterranean Sea) to test the hypothesis of the existence of a unique hake stock (Merluccius merluccius) in the study area. The level of genetic variation was detected from five polymorphic loci (ADH*, PGI-1*, PGI-2*, PGM*, SOD-1*). The average observed heterozygosity amounted to 0.421, while the average expected was 0.353. Weir & Cockerham statistics showed no heterogeneity, except for the single PGI? locus (theta = 0.011; P 0.05). Morphometric analyses revealed some differentiation. Females showed different relationships in six out of eight morphometric indices with total length,…

Larval fish assemblages in the central Mediterranean Sea: spatio-temporal dynamics and biological effects on early life stage of Sardinella aurita (P…

Some Considerations on the Sustainable Urban Development in Romania

2015

Abstract (Promoting an integrated approach is important for sustainable urban development. Most priorities identified during 2007-2013 were not achieved due to the global financial crisis, but also because of the lack of mature projects concerning regional development. As during the previous period, much development needs remain unresolved, including the level of high pollution in the urban areas, vacant, unused and degraded urban areas corresponding to the cities of Romania, as well as valuable resources of cultural heritage which are poorly capitalized. ROP continues during 2014-2020 with a strategic vision on regional development in Romania, contained in the 2007-2013 National Developmen…

Revisiting the Trade-off Between Risk and Incentives: The Shocking Effect of Random Shocks?

2019

Despite its central role in the theory of incentives, empirical evidence of a trade-off between risk and incentives remains scarce. We reexamine this trade-off in a workplace lab environment and find that, in line with theory, principals increase fixed pay while lowering performance pay when the relationship between effort and output is noisier. Unexpectedly, agents produce substantially more in the noisy environment than in the baseline despite weaker incentives. In addition, principals’ earnings are significantly higher in the noisy environment. We show that these findings can be accounted for when agents maximize a non-CARA utility function or when they exhibit loss aversion. Data and t…

Managing satisfaction in cultural events: Exploring the role of core and peripheral product

2017

1.INTRODUCTIONSatisfaction is a key concept within the marketing discipline and specifically within the area of consumer behaviour. Satisfaction in the arts is mostly derived from a combination of three elements: the subjective and experiential aspects of the cultural product, the quality of the venue and the quality of the associated peripheral services (Hume, 2008a). According to this author, studies on satisfaction with cultural events are key to understanding customer motives to repurchase subscription which can increase the arts organization's profitability, this being a main goal of the currently complex entertainment arena.This study focuses on satisfaction among visitors of an art e…

Fish welfare in aquaculture: From physiology to molecular activities and new tools for study innovative diets, social and spatial stress

2022

Guaranteeing a high quality of life for animals has recently become a matter of increasing concern. Welfare assessment has been well-developed for terrestrial species, mainly for those kept in captivity, but the current state of the art is less well-characterized for aquatic animals. The classical methodologies utilised to date, such as the kind of behavioural observation widely used for terrestrial animals, are not appropriate for improving our knowledge of the well-being of aquatic animals if used alone, mainly due to the large number of species and the difficulty of obtaining comparative results among the different taxa of interest. Among different approaches, the evaluation of internal …

Mutation of a critical tryptophan to lysine in avidin or streptavidin may explain why sea urchin fibropellin adopts an avidin-like domain

1999

Sea urchin fibropellins are epidermal growth factor homologues that harbor a C-terminal domain, similar in sequence to hen egg-white avidin and bacterial streptavidin. The fibropellin sequence was used as a conceptual template for mutation of designated conserved tryptophan residues in the biotin-binding sites of the tetrameric proteins, avidin and streptavidin. Three different mutations of avidin, Trp-110-Lys, Trp-70-Arg and the double mutant, were expressed in a baculovirus-infected insect cell system. A mutant of streptavidin, Trp-120-Lys, was similarly expressed. The homologous tryptophan to lysine (W--K) mutations of avidin and streptavidin were both capable of binding biotin and bioti…

The effect of elastic strain on the microstructure of free surfaces of stressed minerals in contact with an aqueous solution

2001

The influence of gradients in bulk elastic strain energy on the dissolution and growth behaviour of minerals in rocks is commonly considered negligible. We experimentally observed, however, that regular arrays of macroscopically visible etch grooves may develop on the originally smooth free surfaces of soluble crystals held in an undersaturated aqueous solution if the crystals are only elastically stressed. These grooves are oriented perpendicular to the compressive stress. They disappear soon after the stress is taken off. The formation of the grooves is well explained by recent theories on the instability of the surface of stressed solids. Development of such instabilities could significa…