Day 1 :
TNO Technical Sciences, The Netherlands
Time : 9:15-10:00
Hartmut R Fischer is a Senior Research Scientist in TNO Technical Sciences and monitors materials’ performance and as such connected with all kinds of materials, their testing and evaluation with a focus on materials under extreme environments and the high end equipment applications. His areas of current activities are the assessment of pavement durability as well as adhesion and surface studies, the study and design of self-healing systems, the investigation and understanding of the micro structure of building materials leading to the design of modern building materials for applications under extreme circumstances. He acts as co-Promoter for PhD students and Mentor of Post-Docs at the TU Eindhoven and Delft in the areas polymer nanocomposites, self-healing systems and transport in porous media. He is also a referee for the German and Dutch Research Council as well as for about 40 scientific journals. He has authored 185 refereed publications, 35 patents and 8 book chapters.
Asphaltenes are a complex mixture of different molecules with similar chemical characteristics which are insoluble in aliphatic solvents (e.g. heptane) but soluble in aromatic ones (e.g. toluene). However, being also known as the ‘cholesterol’ of crude oil, they precipitate, adhere to surfaces and, in the worst cases, cause costly pipe blockages and alter the wetting characteristics of mineral surfaces within the reservoir, hindering oil recovery efficiency. Similar effects are also observed with respect to waxes. Even at very low concentrations in ‘good’ solvents, both still have a strong tendency to form nanoaggregates or nanocrystallites which transfer to micro- and macro-aggregates whose structure and formation remain largely unknown despite much research. Aggregation proceeds from specific strong interaction sites located at the periphery of the asphaltene molecules. They drive the reversible association in two-dimensional sheets, a morphology which is consistent with reported scattering and viscosity data. Precipitation eventually occurs, determined by van der Waals attractions between aggregates, when the solubility parameter of the solvent is shifted. In our current research, we have focused on the several steps to tackle this problem which can heavily impact the economic value of a project, especially in harsh sub-sea environments, where deposition can halt production altogether. For example, intervention costs for asphaltene removal for a land-based well up to $0.5 MM US translates to more than $3 MM US for off-shore well production, and the economic loss as a result of lost/delayed production can amount to $1.2 MM US per day. The ability to predict the occurrence and magnitude of asphaltene deposition in wellbores is critical to forecast the related flow assurance challenges for deep and ultradeep water production. We therefore have the goal to find a solution (chemical, mechanical or otherwise) namely to: a) Understand the issues and help characterize the problem, b) Prevent or inhibit deposition (asphaltene alone or in combination
Roma Tre University, Italy
Time : 10:00-10:45
Fabrizio Paolacci graduated in Civil Engineering in 1992 at the University of Rome "La Sapienza" and completed his PhD in Structural Engineering in 1997. He is currently working as an Assistant Professor in Structural Engineering at University Roma Tre, Department of Engineering. He gained a long standing experience in the management of research projects about experimental assessment of the seismic response of structures. He is currently PI of many European projects. From 2008 to 2013, he assumed the role of Scientific Coordinator of the Laboratory of Testing Materials and Structures of the Department of Structures of the University Roma Tre. He has received a Fellowship provided by CNR (National Research Council) for a research activity of six months at the Department of Civil and Environmental Engineering of University of California at Berkeley from September 1999 to February 2000 as a Visiting Scholar. He is author of more than 100 publications on international peer-reviewed journals and conferences.
Liquid steel storage tanks are strategic structures for industrial facilities and have been widely used both in nuclear and non-nuclear power plants. Typical damage to tanks occurred during past earthquakes such as cracking at the bottom plate, elastic or elastoplastic buckling of the tank wall, failure of the ground anchorage system and sloshing damage around the roof, etc. Due to their potential and substantial economic losses as well as environmental hazards, implementations of seismic isolation and energy dissipation systems have been recently extended to liquid storage tanks. Although the benefits of seismic isolation systems have been well known in reducing seismic demands of tanks; however, these benefits have been rarely investigated in literature in terms of reduction in the probability of failure. In this paper, a vulnerability-based design approach of a sliding concave bearing system for an existing elevated liquid steel storage tank is presented by evaluating the probability of exceeding specific limit states. Firstly, nonlinear time history analyses of a three dimensional stick model for the examined case study are performed using a set of ground motion records. Fragility curves of different failure modes of the tank are then obtained by the well-known cloud method. In the following, a seismic isolation system based on concave sliding bearings is proposed. The effectiveness of the isolation system in mitigating the seismic response of the tank is investigated by means of fragility curves. Finally, an optimization of design parameters for sliding concave bearings is determined based on the reduction of the tank vulnerability or the probability of failure.