Serita Frey Professor of Natural Resources and the Environment (COLSA) travels to Argentina

The Center for International Education provided partial financial support for my sabbatical in Argentina during fall 2015. The specific goals of my trip to Argentina were to (1) visit and interact with a research group at the University of Buenos Aires, (2) explore potential research sites in the Patagonian steppe in southern Argentina, and (3) write several manuscripts and proposals

Space-time paraproducts for paracontrolled calculus, 3d-PAM and multiplicative Burgers equations

We sharpen in this work the tools of paracontrolled calculus in order to provide a complete analysis of the parabolic Anderson model equation and Burgers system with multiplicative noise, in a $3$-dimensional Riemannian setting, in either bounded or unbounded domains. With that aim in mind, we introduce a pair of intertwined space-time paraproducts on parabolic H\"older spaces, with good continuity, that happens to be pivotal and provides one of the building blocks of higher order paracontrolled calculus.Comment: v3, 56 pages. Different points about renormalisation matters have been clarified. Typos correcte

Studies of the major planet satellite systems

A summary is presented of the available data on the satellites of the major planets, including the currently most plausible models for several observed phenomena, for the planning of spacecraft missions to these objects. Some of the important questions likely to be solved by flyby and/or orbital missions to the giant planets are detailed, the importance of these studies to our understanding of the solar system as a whole is indicated

Stiff Polymers, Foams and Fiber Networks

We study the elasticity of fibrous materials composed of generalized stiff polymers. It is shown that in contrast to cellular foam-like structures affine strain fields are generically unstable. Instead, a subtle interplay between the architecture of the network and the elastic properties of its building blocks leads to intriguing mechanical properties with intermediate asymptotic scaling regimes. We present exhaustive numerical studies based on a finite element method complemented by scaling arguments.Comment: 4 pages, 5 figure

Elasticity of Stiff Polymer Networks

We study the elasticity of a two-dimensional random network of rigid rods (``Mikado model''). The essential features incorporated into the model are the anisotropic elasticity of the rods and the random geometry of the network. We show that there are three distinct scaling regimes, characterized by two distinct length scales on the elastic backbone. In addition to a critical rigidiy percolation region and a homogeneously elastic regime we find a novel intermediate scaling regime, where elasticity is dominated by bending deformations.Comment: 4 pages, 4 figure

Comparative planetology: Significance for terrestrial geology

The crustal evolution of the terrestrial planets increase in complexity and duration with increasing size and mass of the planet. The lunar and mercurian surfaces are largely the result of intense, post-differentiation impact bombardment and subsequent volcanic filling of major impact basins. Mars, being larger, has evolved further: crustal uplifts, rifting, and shield volcanoes have begun to modify its largely Moon-like surface. The Earth is the large end-number of this sequence, where modern plate tectonic processes have erased the earlier lunar and martian type of surfaces. Fundamental problems of the origin of terrestrial continents, ocean basins, and plate tectonics are now addressed within the context of the evolutionary pattern of the terrestrial planets

Development of new ecological footprint techniques applicable to consumer electronics

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In order to extend ecological footprint analysis (EFA) to electronic products, new methods had to be developed which associate the world average bioproductive space per capita and year - the fair Earth share - with an individual product. The problem analysed in this thesis is the need for an environmental assessment tool for electronic products, which uses natural capital accounting. This need arose because so far, electronic products were mainly assessed using life cycle analysis with a focus on toxicity. Since the ecological footprint (EF) is a sustainability indicator, the sustainability discussion and in particular its relevance and implications with regard to the EF is reviewed. The electronic products assessed in this thesis are a personal computer (PC) in an exploratory study, and three mobile phones (two main case studies and one updated case study). To establish the land areas used by the mined materials used in electronic products, a database was developed based on site specific data found in the literature, and on approximations from the density of materials and their overburden. A life cycle energy approach was used to determine the burdens from producing and using a mobile phone. In order to estimate energy requirements for materials for which no data was available, the relationship between abundance and rucksack / overburden values was used in a regression analysis. Direct land use data and results from the energy analysis were used as an inventory for the subsequent EFA. An EF time series was applied to represent a more accurate picture of PC and phone use. This was also necessary since the EF reflects the instantaneous rate (a snapshot) of resource consumption. Key results are that the EF of electronic products are much larger than their actual size and that different electronic products have different EF. Our methodology proved sensitive enough to reveal differences even in small electronic products, given the high benchmark of a fair Earth share, and useful in monitoring space-efficient technology