134 research outputs found

    Preliminary results of investigations of possible ground deformation structures in the early christian basilica, ancient Lechaion harbour, Corinth, Greece.

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    Η Παλαιοχριστιανική Βασιλική Λεχαίου, Κόρινθος, κατασκευάστηκε στα τέλη του 5ου αι. μ.Χ. στον δυτικό βραχίονα του αρχαίου λιμανιού του Λεχαίου, και σύμφωνα με αρχαιολογικές ανασκαφές καταστράφηκε από την σεισμική δραστηριότητα του 551-552 μ.Χ.. Διάσπαρτα βυθίσματα και υβώματα που παρατηρήθηκαν στο δάπεδο της Βασιλικής αποτελούν ενδεικτικές δομές εδαφικής παραμόρφωσης η οποία πιθανόν να σχετίζεται με ρευστοποίηση εδάφους. Με στόχο την διερεύνηση της στρωματογραφίας και της δομής του υπεδάφους πραγματοποιήθηκαν γεωφυσικές διασκοπήσεις GPR και μετρήσεις αγωγιμότητας του εδάφους κατά μήκος δέκα επιλεγμένων τομών και συσχέτιση τους με τη στρωματογραφία όπως αυτή περιγράφεται από αρχαιολογικά σκάμματα. Τα αποτελέσματα της μελέτης είναι ενδεικτικά δομών παραμόρφωσης των υποκείμενων εδαφικών σχηματισμών με χαρακτηριστικά που επιτρέπουν την συσχέτιση των επιφανειακών δομών που παρατηρήθηκαν στο δάπεδο της Βασιλικής με το φαινόμενο της ρευστοποίησης εδάφους.The Early Christian Basilica of Lechaion, Corinth, located on the western jetty of the ancient Lechaion harbour, was constructed during the late 5th century AD and archaeological excavations suggest that it was destroyed by seismic activity during 551-552 AD. Numerous depressions and buckling structures observed on the Basilica floor are indicative of ground deformation structures, likely associated with liquefaction. In an attempt to investigate the subsurface soil structure, and stratigraphy, a GPR survey and horizontal distribution of ground conductivity along ten selected transects was carried out, supplemented by stratigraphic data as described by archaeological trenches. The results of the study revealed subsurface deformation features providing sufficient indications that allow us to suggest that the surface structures observed on the Basilica floor are the surface expression of earthquake-induced ground liquefaction

    “Availability is the poor cousin of marketing and pricing”: qualitative study of stakeholders’ views on policy priorities around tobacco and alcohol availability

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    Background: Reducing alcohol and tobacco availability is one potential way to reduce harm from these unhealthy commodities. This study explores key stakeholders’ views in relation to policy priorities and considerations for both alcohol and tobacco availability. Methods: We conducted semi-structured interviews with 14 stakeholders from alcohol and/or tobacco third sector organizations, government, public health and licensing in Scotland. Interviews explored their views on alcohol/tobacco availability, including its place in the policy landscape and experiences in gaining support for policies. Data were analyzed using thematic analysis. Results: Stakeholders believed that alcohol and tobacco availability have not received as much policy attention as pricing and marketing. Stakeholders highlighted the importance of public support and having sufficient evidence to inform policy. Key considerations for future policies include: drawing on lessons from tobacco control policies to address alcohol availability, considering different aspects of availability (especially online availability), ensuring policies reflect their local context, considering the impact of policies on children, and managing retailers’ involvement in the policy process. Conclusion: This study highlights key considerations for policies to address alcohol and tobacco availability. There is a need for more research to consider retailers’ views and provide greater detail on specific policy suggestions.</p

    Exploring the influence of local alcohol availability on drinking norms and practices: a qualitative scoping review

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    Introduction: High alcohol availability is related to increased alcohol consumption and harms. Existing quantitative research provides potential explanations for this relationship but there is little understanding of how people experience local alcohol availability. This is the first review to synthesise qualitative research exploring the relationship between alcohol availability and other factors in local alcohol environments. Methods: The scoping review includes qualitative studies exploring community‐level alcohol availability and other factors, facilitating the purchase and consumption of alcohol. We included studies focusing on children and adolescents as well as adults. Study findings were brought together using thematic analysis and the socio‐environmental context model, which explains how certain environments may facilitate drinking. Results: The review includes 34 articles. The majority of studies were conducted since 2012. Most studies were conducted in the United Kingdom, Australia and South Africa. The physical availability of alcohol and proximity to local amenities and temporal aspects, like late night opening hours, may be linked to social factors, such as normalisation of drinking and permissive drinking environments. The review highlights the importance of social and cultural factors in shaping interactions with local alcohol environments. Discussion and Conclusion: This qualitative scoping review advances understanding of the pathways linking alcohol availability and alcohol harms by showing that availability, accessibility and visibility of alcohol may contribute towards permissive drinking environments. Further research is needed to better understand how people experience alcohol availability in their local environment and how this can inform alcohol control policies

    Active Brownian Particles. From Individual to Collective Stochastic Dynamics

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    We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically powered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active particles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte

    From bore-soliton-splash to a new wave-to-wire wave-energy model

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    We explore extreme nonlinear water-wave amplification in a contraction or, analogously, wave amplification in crossing seas. The latter case can lead to extreme or rogue-wave formation at sea. First, amplification of a solitary-water-wave compound running into a contraction is disseminated experimentally in a wave tank. Maximum amplification in our bore–soliton–splash observed is circa tenfold. Subsequently, we summarise some nonlinear and numerical modelling approaches, validated for amplifying, contracting waves. These amplification phenomena observed have led us to develop a novel wave-energy device with wave amplification in a contraction used to enhance wave-activated buoy motion and magnetically induced energy generation. An experimental proof-of-principle shows that our wave-energy device works. Most importantly, we develop a novel wave-to-wire mathematical model of the combined wave hydrodynamics, wave-activated buoy motion and electric power generation by magnetic induction, from first principles, satisfying one grand variational principle in its conservative limit. Wave and buoy dynamics are coupled via a Lagrange multiplier, which boundary value at the waterline is in a subtle way solved explicitly by imposing incompressibility in a weak sense. Dissipative features, such as electrical wire resistance and nonlinear LED loads, are added a posteriori. New is also the intricate and compatible finite-element space–time discretisation of the linearised dynamics, guaranteeing numerical stability and the correct energy transfer between the three subsystems. Preliminary simulations of our simplified and linearised wave-energy model are encouraging and involve a first study of the resonant behaviour and parameter dependence of the device
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