Hydrostatic Collapse Tests of Full-Scale Pipeline Specimens With Thickness Metal Loss

The present paper deals with the subject of failure of deep-sea pipelines that have thickness metal-loss areas caused by corrosion and are subjected to high external hydrostatic pressure. An extensive research program was launched to observe failure modes, to examine existing and to develop prediction collapse equations, and to determine their accuracy. The program uses finite element modeling and external hydrostatic collapse tests of full-scale specimens. This paper presents and discusses the results of the first 20 collapse tests, which were performed in a new 103 MPa (15 ksi) hyperbaric chamber (760 mm internal diameter and 7200 mm length). The test results obtained with full scale specimens (324 mm external diameter and 23 mm thickness) made of low carbon steel API 5L X60 with external machined metal loss defects are used to verify the level of accuracy and conservatism of four analytical simple equations used to predict collapse of pipes with corrosion subjected to high external pressure.

General Tendencies of the Behaviour of Vegetables Developed in a Soil Contaminated with Heavy Metals

The paper presents experimental results obtained in the study of heavy metals transfer from soil to vegetables. The experiments for which the raw and statistically processed data are presented in this paper are preliminary experiments within an extensive research program of plant behaviour in soils contaminated with heavy metals. These experiments underlie the development of primary statistical mathematical models that are also presented in the paper. These experiments will also form the basis for far more consistent experiments that follow plants throughout the life cycle. The statistical mathematical models presented in this paper facilitate extracting important conclusions about how plants accumulate heavy metals as well as about the accumulation rate behaviour during experiments. Both experiments and mathematical models will form the basis of complex experiments and dynamic mathematical models in the next stage of research.

Capital stock in Spain and its distribution by territories (1964-2012)

Since 1995 the BBVA Foundation and the Ivie have been conducting an extensive research program on Spanish economic growth. The regularly-updated database "Capital stock in Spain and its distribution by territories" are the basis of this program, providing information on the accumulation of capital in Spain over the last four decades.

Dynamic Monitoring and Seismic Response of a Historic Masonry Tower

After the Italian earthquakes of May 2012, an extensive research program had been performed to assess the state of preservation of the tallest historic tower in Mantua, Italy. Subsequently, a continuous dynamic monitoring system was installed in the tower, with seismic and structural health monitoring purposes. After a brief description of the investigated tower and its state of preservation, the paper summarizes some results of the long-term dynamic monitoring.

Load Carrying Elements and Structural Modular Systems Made of Synthetic Fibres Reinforced Mineral Matrix Composite

The use of recyclable materials is a priority for the construction industry aiming to a sustainable development. Recent works have shown that calcium sulphate in the β anhydride III form which is a hydraulic binder manufactured from industrial wastes can partially replace ordinary Portland cement in construction elements. Alkali resistant glass fibres can be used as reinforcement for ecological mineral matrix in order to obtain a mineral composite material. In the framework of an extensive research program, load carrying elements and structural modular system entirely made of mineral composite material were designed, developed, tested, analyzed and implemented. The paper presents the selection of efficient mixes for a mineral matrix with convenient mechanical properties, good workability and encouraging prospects to be implemented in construction elements and full structural systems. The experimental work carried out confirms the suitability of this material for load bearing elements and modular building systems.

From Exxon to BP: Has Some Number Become Better than No Number?

On March 23, 1989, the Exxon Valdez ran aground in Alaska's Prince William Sound and released over 250,000 barrels of crude oil, resulting in 1300 miles of oiled shoreline. The Exxon spill ignited a debate about the appropriate compensation for damages suffered, and among economists, a debate concerning the adequacy of methods to value public goods, particularly when the good in question has limited direct use, such as the pristine natural environment of the spill region. The efficacy of stated preference methods generally, and contingent valuation in particular, is no mere academic debate. Billions of dollars are at stake. An influential symposium appearing in this journal in 1994 provided arguments for and against the credibility of these methods, and an extensive research program published in academic journals has continued to this day. This paper assesses what occurred in this academic literature between the Exxon spill and the BP disaster. We will rely on theoretical developments, neoclassical and behavioral paradigms, empirical and experimental evidence, and a clearer elucidation of validity criteria to provide a framework for readers to ponder the question of the validity of contingent valuation and, more generally, stated preference methods.

A CONNECTIONIST ABM OF SOCIAL CATEGORIZATION PROCESSES

This paper introduces a connectionist Agent-Based Model (cABM) that incorporates detailed, micro-level understanding of social influence processes derived from laboratory studies and that aims to contextualize these processes in such a way that it becomes possible to model multidirectional, dynamic influences in extended social networks. At the micro-level, agent processes are simulated by recurrent auto-associative networks, an architecture that has a proven ability to simulate a variety of individual psychological and memory processes [D. Van Rooy, F. Van Overwalle, T. Vanhoomissen, C. Labiouse and R. French, Psychol. Rev. 110, 536 (2003)]. At the macro-level, these individual networks are combined into a "community of networks" so that they can exchange their individual information with each other by transmitting information on the same concepts from one net to another. This essentially creates a network structure that reflects a social system in which (a collection of) nodes represent individual agents and the links between agents the mutual social influences that connect them [B. Hazlehurst, and E. Hutchins, Lang. Cogn. Process. 13, 373 (1998)]. The network structure itself is dynamic and shaped by the interactions between the individual agents through simple processes of social adaptation. Through simulations, the cABM generates a number of novel predictions that broadly address three main issues: (1) the consequences of the interaction between multiple sources and targets of social influence (2) the dynamic development of social influence over time and (3) collective and individual opinion trajectories over time. Some of the predictions regarding individual level processes have been tested and confirmed in laboratory experiments. In a extensive research program, data is currently being collected from real groups that will allow validating the predictions of cABM regarding aggregate outcomes.

Mechanical and Physical Properties of Nano-Metals

In the present work, an extensive research program has been undertaken to characterise a wide spectrum of properties of nano-metals. In particular, the effect of grain refinement on such properties as fatigue, corrosion and wear resistance, conductivity and thermal stability has been studied for various nano-metals (aluminium, copper and iron alloys). The results have revealed that nano-grain refinement also improves physical properties of single phase metals. A disadvantageous effect of large (micron sized) particles, which do not undergo refinement during the processing, has been also recognized.

Towards a New Limit State Function for Determining the Failure Pressure of a Pipeline Containing Mechanical Damage

Mechanical damage is generally considered to be damage that occurs to a pipeline when mechanical excavation, drilling, or boring equipment impinges on a buried pipeline creating scrapes, abrasions, gouges, punctures, and/or dents in the pipeline. Above ground pipelines may also be damaged in a similar manner from impacts by vehicles or projectiles or by willful acts of vandalism. In some cases, immediate failure will occur resulting in potentially catastrophic consequences. It is thus important to understand the conditions that would lead to such a failure in order to ensure that design parameters are selected such that immediate failures occur very rarely. In cases where the damage does not create an immediate failure or the release of gas, the concern generally is that a delayed failure will occur because the integrity of the pipeline has been significantly compromised. In such cases, the possibility is that repeated pressure fluctuations, small increases in pressure, or time-dependent creep will erode whatever margin of safety remains and a failure will ensue. Particularly unsettling are the cases in which damage of this nature is encountered through some form of inspection where the source of the damage and its time of creation are unknown. In such cases, the operator of the pipeline will generally not know what margin of safety remains. There are a number of models in existence that may be used to predict both instantaneous and delayed failures due to mechanical damage and indeed these have been used quite extensively as the basis of repair criteria and for determining safe pipeline operating conditions. Nonetheless, there are significant elements of uncertainty associated with these models and for this reason an adequate reserve factor needs to be incorporated or recourse must be made to probabilistic approaches that address such uncertainty. However, since pipelines are getting older and in some cases are being operated at higher pressures than they were previously, there is a requirement to obtain a better understanding of the significance of mechanical damage. In view of this Pipelines Research Council International (PRCI) and other research bodies, such as European Pipelines Research Group (EPRG), are taking a keen interest in this topic. To this end, PRCI have commissioned an extensive research program to investigate all key aspects of both instantaneous and delayed failures. Kiefner and Associates Incorporated (KAI) and Andrew Francis and Associated Ltd (AFAA) were commissioned to investigate the conditions that cause instantaneous failures. The purpose of this paper is to describe the approach that was adopted and the formulation of the new model that emerged from study. This model is being validated through testing which is currently ongoing.

Finn Kydland and Edward Prescott: Driving Forces behind Economic Cycles (2004 Nobel Prize in Economics)

The method of analyzing and modeling cyclical fluctuations of economy initiated by F. Kydland and E. Prescott - the 2004 Nobel Prize winners in Economics - is considered in the article. They proposed a new business cycle theory integrating the theory of long-run economic growth as well as the microeconomic theory of consumers and firms behavior. Simple version of general dynamic and stochastic macroeconomic model is described. The given approach which was formulated in their fundamental work "Time to Build and Aggregate Fluctuations" (1982) gave rise to an extensive research program and is still used as a basic instrument for investigating cyclical processes in economy nowadays.