Evaluation of dynamic explicit mpm formulations for unsaturated soils

Many applications in geohazards prevention involve large deformations of unsaturated soils, e.g. rainfall induced landslides, embankment collapses due to wetting etc. These phenomena can be investigated with multiphase implementations of the Material Point Method (MPM) able to account for the behaviour of unsaturated soils. This paper compares two formulations: (i) afully coupled three-phase formulation(3P)in which the governing equations are derived from the momentum balance and the mass balance equations of solid, liquid and gas phase assuming non-zero gas pressure,the primary unknowns are the absolute accelerationsof the phases (aS–aL–aG formulation); (ii)a simplified approachthatneglectsthe momentum balance equation of the gas(2P_s).Potentialities and limitations of these approaches are highlighted consideringa 1D infiltration problem.Despite the introduced simplifications, the simplified formulation gives reasonably good results in many engineering cases

Introduction to Focus Section: The Geographies of Crime and Policing in the Global Countryside

This focus section aims to identify, conceptualize, and understand the emerging geographies of rural crime, in particularthose of globalized rural crime, and evaluate their impact on different rural places. Contributions to this focus sectionreflect an interdisciplinary array of fields from geography, economy, and criminology to rural studies, fully engaged withpertinent theories and state-of-the-art literature. The focus section also critically examines how security and policing ofrural areas is delivered by existing and emerging agencies, drawing from evidence from different country contexts inBrazil, the United States, the United Kingdom, and Sweden.QC 20220117</p

Aim, scope, conceptual framework and definitions

Mobility is a basic requirement of modern society. Distance separates individuals’ homes from places where they work, shop, do business, undertake leisure and recreational activities, and socially interact. Public transit plays a key role in reducing social exclusion by offering access to these fundamental life activities. For example, in Sweden and in Great Britain, one-quarter of households do not own a car (SIKA, 2008; DfT, 2012). Moreover, access to a car is not equally distributed amongst the population, and varies by age, gender, ethnicity and socio-economic status. Particular groups are more reliant on public transportation than others (Kunieda and Gauthier, 2007; Raphael et al. 2006). Furthermore, there are obvious environmental benefits in promoting public transport as a means of sustainable travel (Steg and Gifford, 2005). Since public transportation is a cornerstone of sustainable development, passengers deserve convenient and reliable transportation systems. However, getting people to use public transportation systems is not just a matter of making them efficient and cost effective. Passengers need to feel safe not just at stops and stations but also during their entire journey. Transportation systems encompass more than buses, trains and infrastructure. They constitute actual transit environments in which individuals spend time on a daily basis and are, therefore, important settings in everyday life. Indeed, one in five Europeans spend on average more than two hours a day commuting in these transit environments (Stepstone, 2012)

Theoretical perspectives of safety and security in transit environments

This chapter discusses the extant theories used to explain safety and security in transit environments, which are set out within the conceptual framework identified in the previous chapter. A number of theoretical perspectives have been developed to explain the prevalence of crime, disorder and associated fear in society. None of these are without criticism, and none have been developed explicitly for the purpose of explaining safety and security on public transport systems. This section examines current security and criminological theories, and ideas and perspectives from other fields and disciplines, to ascertain their utility for explaining safety and security specifically in the context of public transportation. The aim is to translate these theories into an integrated and theory-led conceptual framework within which safety and security on public transport systems can readily be examined

Practical challenges and new research frontiers for safety and security in transit environments

This chapter brings together this edited volume, and highlights and summarizes the main findings presented in the book, based on each of the preceding five sections. It examines the conceptual framework, and the main findings that arise from each section. These include safety and security at the transit node, the journey, links to the surrounding settings and the perspective of the user. It provides an overview of why safety and security is challenging and complex, and discusses the utility of the conceptual framework in tackling this. It then suggests new research frontiers for safety in transit environments, before concluding with some recommendations for future policy

Crime at the intersection of rail and retail

This chapter examines shoplifting at rail station shops over a 12 month period in England and Wales. Key findings were: shoplifting is concentrated at particular stations; the top 20 stations account for 85% of shoplifting. Clear temporal patterns were evident; shoplifting was higher on weekdays and during holidays with higher levels of travel; shoplifting is lower when there is a reduced rail service. There was no clear relationship between shoplifting rates outside of a station at shops nearby, and shoplifting within a rail station. It is suggested a correlation may occur for medium and smaller size stations. Large stations may attract offenders in their own right without other shops being nearby. The similarities observed between shoplifting patterns at rail stations and those at non-rail station shops suggest the learning from successful crime prevention measures applied outside of the rail environment could successfully transferred to rail stations

Romanian ancient gold objects provenance studies using micro-beam methods: the case of "Pietroasa" hoard

Abstract Five fragments of ancient gold objects belonging to Pietroasa "Closca cu Puii de Aur" ("The Golden Brood Hen with Its Chickens") Romanian hoard were analysed using the micro-PIXE (particle induced X-ray emission) technique. The purpose of the study was to gain some more knowledge regarding the metal provenance by determining the presence of PGE (Platinum Group Elements) and other high-temperature melting point trace elements (Ta, Nb, Cr) at a micrometric scale. Ta and Nb inclusions (micrometric areas of composition different from the surroundings) on three samples and Pd inclusions on one sample were found. The measurements led to some conclusions for the possible gold ore sources of Pietroasa treasury: the South-Ural Mountains, Nubia (Sudan) and/or Anatolian deposits and Roman imperial coins

Editorial: crime patterns in time and space: the dynamics of crime opportunities in urban areas

The routine activity approach and associated crime pattern theory emphasise how crime emerges from spatio-temporal routines. In order to understand this crime should be studied in both space and time. However, the bulk of research into crime patterns and related activities has investigated the spatial distributions of crime, neglecting the temporal dimension. Specifically, disaggregation of crime by place and by time, for example hour of day, day of week, month of year, season, or school day versus none school day, is extremely relevant to theory. Modern data make such spatio-temporal disaggregation increasingly feasible, as exemplified in this special issue. First, much larger data files allow disaggregation of crime data into temporal and spatial slices. Second, new forms of data are generated by modern technologies, allowing innovative and new forms of analyses. Crime pattern analyses and routine activity inquiries are now able to explore avenues not previously available. The unique collection of nine papers in this thematic issue specifically examine spatio-temporal patterns of crime to; demonstrate the value of this approach for advancing knowledge in the field; consider how this informs our theoretical understanding of the manifestations of crime in time and space; to consider the prevention implications of this; and to raise awareness of the need for further spatio-temporal research into crime event