megastructures use of cfd turbulence models for the evaluation of wind induced fatigue loads

Abstract: The determination of time dependent wind actions on large civil steel structures by means of turbulence models for CFD allows an improved evaluation of the fatigue load spectrum. The purpose of this paper is to identify, from literature review, the flow characteristics required to conduct a proper assessment of a fatigue load spectrum, given that practical cases determine which are the properties of the flow to be relevant. Subsequently, some CFD turbulence models are presented in order to investigate their ability to provide the required outputs with an appropriate level of detail. The computational cost of the models is also considered

The Human Sweet Tooth

Humans love the taste of sugar and the word "sweet" is used to describe not only this basic taste quality but also something that is desirable or pleasurable, e.g., la dolce vita. Although sugar or sweetened foods are generally among the most preferred choices, not everyone likes sugar, especially at high concentrations. The focus of my group's research is to understand why some people have a sweet tooth and others do not. We have used genetic and molecular techniques in humans, rats, mice, cats and primates to understand the origins of sweet taste perception. Our studies demonstrate that there are two sweet receptor genes (TAS1R2 and TAS1R3), and alleles of one of the two genes predict the avidity with which some mammals drink sweet solutions. We also find a relationship between sweet and bitter perception. Children who are genetically more sensitive to bitter compounds report that very sweet solutions are more pleasant and they prefer sweet carbonated beverages more than milk, relative to less bitter-sensitive peers. Overall, people differ in their ability to perceive the basic tastes, and particular constellations of genes and experience may drive some people, but not others, toward a caries-inducing sweet diet. Future studies will be designed to understand how a genetic preference for sweet food and drink might contribute to the development of dental caries