Prediction of ductile fracture in anisotropic steels for pipeline applications

Large diameter steel pipelines for gas transportation may experience extreme overloads due to external actions such as soil sliding, faults movements, third part interactions. In these scenarios the material undergoes severe plastic strains which locally may reach the fracture limits. Due to the manufacturing process, the steels used in such applications have an anisotropic behavior both for plasticity and fracture. In this paper two steel grades have been characterized in view of anisotropic plastic fracture. Fracture tests have been planned to characterize the fracture behavior under different stress states and in different directions to define the anisotropic sensitivity. Finite element modelling, incorporating an anisotropic plasticity formulation, has been used to calculate the local fracture parameters in the specimens and to define the complete ductile fracture locus. An uncoupled damage evolution law has been finally used to evaluate the fracture limits on real pipelines failed in full scale laboratory tests. The strain to fracture prediction has been verified by local strain measurements on the fractured pipes. The model robustness has been also verified on global parameter predictions, such us the burst pressur

An analysis of preferences of sixth grade elementary pupils in the field of language.

Thesis (Ed.M.)--Boston Universit

We are More Than our Executive Functions: on the Emotional and Situational Aspects of Criminal Responsibility and Punishment

In Responsible Brains (MIT Press, 2018), Hirstein, Sifferd and Fagan apply the language of cognitive neuroscience to dominant understandings of criminal responsibility in criminal law theory. The Authors make a compelling case that, under such dominant understandings, criminal responsibility eventually ‘translates’ into a minimal working set of executive functions (MWS) that are primarily mediated by the frontal lobes of the brain. In so arguing, the Authors seem to unquestioningly accept the law’s view of the “responsible person” as a mixture of cognitive capacities and mechanisms—thereby leaving aside other fundamental aspects of individuals’ human agency. This commentary article offers a critique of the Authors’ rationalist and individualist approach. The critique can be summarized through the following claim: We humans, as responsible beings, are more than our executive functions. This claim articulates through four main points of discussion: (1) role of emotions in moral judgments and behavior; (2) executive functions and normative criteria for legal insanity; (3) impact of adverse situational factors on executive functions; (4) Authors’ account of punishment and, especially, rehabilitation

Sustainability assessment of wheat production using Emergy

Sustainability of crop production has to be given high priority when global biomass resources are limited. Here emergy evaluation is applied in order to assess sustainability of crop production exemplified by winter wheat. Emergy evaluation takes into account all inputs involved in a production system (i.e. renewable and non-renewable, local and imported) and transforms them into a common measure of direct and indirect solar energy requirement. The evaluation of winter wheat production is conducted by comparing conventional and organic management on two soil types using Danish reference conditions. The resource use efficiency of wheat production per kg biomass is higher using conventional management practices. This is due to high yield based on large use of non-renewable resources. The environmental loading ratio from organic management practices is about a third of the conventional implying that the organic management can be considered more sustainable

Estimating and visualizing perceived accessibility to transportation and urban facilities

In this paper we present some estimated functions of residential location utility, perceived by individuals, varying with the distance from selected transportation and urban facilities, such as metro and train stations, highway and road junctions, as well as hospitals, green spaces and leisure centres. By summing up such functions we get a measure of the overall convenience of residing in different zones of a given study area, that we call “perceived accessibility”. The functions, estimated by means of SP-surveys, have been implemented into an accessibility Interactive Visualisation Tool (i.e. InViTo) and applied to case study of Rome (Italy). The application allows to validating the use of interactive visualization tools to measure accessibility and its potential usability to produce easy-to-read accessibility maps of urban scenarios of urban development

Chemical Looping for Combustion of Solid Biomass: A Review

Chemical looping combustion of solid biomass has the unique potential to generate energy with negative carbon emissions, while entailing an energy penalty compared to traditional combustion that is lower than that of the competing carbon capture technologies. In spite of these attractive features, research is still needed to bring the technology to a fully commercial level. The reason relies on a number of technological challenges mostly related to the oxygen carrier performance, its possible detrimental interaction with the biomass ash components, and the efficiency of the gas-solid contact with the biomass volatiles. This review is focused on these specific challenges which are particularly relevant when firing biomass rather than coal in a solid-based chemical looping combustion process. Special attention will be given to the most recent findings published on these aspects. Related performance evaluation by modeling, system integration, and techno-economic analysis will also be briefly reviewed

Future mobility and land use scenarios: Impact assessment with an urban case study

In recent years the interest in urban mobility has grown considerably, not only due to the local increase in negative externalities generated by transport, but also because recent technological innovations are offering effective solutions especially in urban context. In particular, the introduction of Connected and Automated Vehicles (CAVs) could radically change the mobility scenario allowing, on the one hand, a widespread diffusion of shared vehicles that could feed the stations of the mass rapid transit network, improving the attractiveness of Public Transportation (PT), and on the other, the implementation of Travel Demand Management (TDM) measures on large areas of the most densely urbanized (and congested) territory of a city, without reducing accessibility and creating social exclusion. The present study aims at evaluating, through a system of Land-Use Transportation Interaction (LUTI) models, the impacts on transport demand and on population and activities location, of transportation policies oriented to both enhancing PT and restricting the individual use of the car. The case study analyzed is represented by the urban area of Rome. Several scenarios have been simulated and compared by means of sustainability indicators. Preliminary results show that the improvement of PT services, combined with the introduction of car use restriction and car free areas, do induce not only a significant modal shift towards more sustainable transportation modes, but also a limitation of urban sprawl

The response of precipitation characteristics to global warming from climate projections

Abstract. We revisit the issue of the response of precipitation characteristics to global warming based on analyses of global and regional climate model projections for the 21st century. The prevailing response we identify can be summarized as follows: increase in the intensity of precipitation events and extremes, with the occurrence of events of "unprecedented" magnitude, i.e., a magnitude not found in the present-day climate; decrease in the number of light precipitation events and in wet spell lengths; and increase in the number of dry days and dry spell lengths. This response, which is mostly consistent across the models we analyzed, is tied to the difference between precipitation intensity responding to increases in local humidity conditions and circulations, especially for heavy and extreme events, and mean precipitation responding to slower increases in global evaporation. These changes in hydroclimatic characteristics have multiple and important impacts on the Earth's hydrologic cycle and on a variety of sectors. As examples we investigate effects on potential stress due to increases in dry and wet extremes, changes in precipitation interannual variability, and changes in the potential predictability of precipitation events. We also stress how the understanding of the hydroclimatic response to global warming can provide important insights into the fundamental behavior of precipitation processes, most noticeably tropical convection

An artificial neural network technique for downscaling GCM outputs to RCM spatial scale

Abstract. An Artificial Neural Network (ANN) approach is used to downscale ECHAM5 GCM temperature (T) and rainfall (R) fields to RegCM3 regional model scale over Europe. The main inputs to the neural network were the ECHAM5 fields and topography, and RegCM3 topography. An ANN trained for the period 1960–1980 was able to recreate the RegCM3 1981–2000 mean T and R fields with reasonable accuracy. The ANN showed an improvement over a simple lapse-rate correction method for T, although the ANN R field did not capture all the fine-scale detail of the RCM field. An ANN trained over a smaller area of Southern Europe was able to capture this detail with more precision. The ANN was unable to accurately recreate the RCM climate change (CC) signal between 1981–2000 and 2081–2100, and it is suggested that this is because the relationship between the GCM fields, RCM fields and topography is not constant with time and changing climate. An ANN trained with three ten-year "time-slices" was able to better reproduce the RCM CC signal, particularly for the full European domain. This approach shows encouraging results but will need further refinement before becoming a viable supplement to dynamical regional climate modelling of temperature and rainfall