99 research outputs found
The mechanism of steady friction between seabed pipelines and clay soils
No full textThe large-amplitude lateral soil resistance between an on-bottom pipeline and the seabed is an important design parameter in assessing pipeline behaviour during lateral thermal buckling or under the impact of a submarine slide. This paper describes a series of centrifuge model tests that shed light on the underlying behaviour during large-amplitude lateral pipe movement. It is shown that at large displacements the lateral response is governed predominantly by the passive resistance of the growing berm of soil ahead of the pipe. Using a new analysis of this growing soil berm, based on conservation of volume, the 'local' embedment of the pipe relative to the top of the idealised soil berm is defined. In this way, the normalised lateral pipe-soil resistance, H/suD, from tests encompassing a range of pipe weights and initial embedments follows a single trend line. This idealisation of the response is more consistent than the usual terminology of a pipe-soil friction factor.</p
Failure mechanisms in soft soil berms during lateral buckling of pipelines: A centrifuge modelling study using PIV analysis
No full textMechanisms of pipe embedment and lateral breakout on soft clay
No full textPipelines laid on the seabed expand and contract during operating cycles as a result of thermal loading, which can lead to lateral buckling. Analysis of this behaviour requires assessment of the vertical penetration and lateral breakout responses. This paper reports centrifuge modelling of these processes, using advanced image analysis techniques to observe the soil deformation. Simple mechanisms are fitted to the observed deformation patterns, allowing the mobilized soil strength to be back-calculated. The vertical embedment mechanisms closely match plasticity solutions. Even if heave is accounted for, the penetration resistance is slightly higher than calculations based on the undrained strength inferred from a T-bar penetrometer. This discrepancy can be attributed to the additional remoulding and softening during steady flow around a T-bar compared to shallow pipe penetration. The lateral breakout response is brittle, and the peak resistance is governed by the available tensile resistance behind the pipe. During steady lateral sweeping the pipe rises close to the original soil surface. At this stage the resistance is governed by the growth of a soil berm ahead of the pipe. Accurate assessment of the near-surface soil strength is difficult, hampering the use of theoretical solutions.</p
Upper bound plasticity analysis of a partially-embedded pipe under combined vertical and horizontal loading
No full textSeabed pipelines undergo temperature cycles that create axial load which can be relieved through controlled lateral buckling. The prediction of lateral buckling in design requires accurate assessment of the lateral breakout resistance. This Technical Note describes upper bound plasticity analysis of a partially-embedded pipe on undrained soil. The purpose is to generate failure envelopes for vertical and horizontal loading to provide a theoretical basis for estimating breakout resistance. The following cases have been considered: smooth and rough pipes, with and without separation at the rear face of the pipe. The envelopes are similar to those developed previously for surface foundations, but capture additional effects that are due to the curved geometry of the pipe surface. The breakout resistance and the movement of the pipe at failure are strongly influenced by the separation condition. Pipe roughness and soil self-weight have a relatively minor effect on breakout resistance. Existing empirical expressions usually assume a linear variation in breakout resistance with embedment and vertical load. This theoretical analysis demonstrates that these relationships are non-linear. The resulting envelopes provide a more rigorous basis for predicting the breakout resistance of partially-embedded pipelines.</p
On the Sherlocks, Jane Coleman and County Kildare in the Eighteen Forties
No full textIn the late 1980s and early 1990s the author acquired about 30,000 letters written mainly in the 1840s. These pertained to estates throughout Ireland managed by the firm of James Robert Stewart and Joseph Kincaid, hereafter denoted SK. Until the letters – called the SK correspondence in what follows – became the author’s property, they had not seen light of day since the 1840s. Addressed mainly to the firm’s office in Dublin, they were written by landlords, tenants, the partners in SK, local agents, etc. After about 200 years in operation as a land agency, the firm in which members of the Stewart family were the principal partners – Messrs J. R. Stewart & Son(s) from the mid- 1880s onwards – ceased operations in the mid-1980s. Since 1994 the author has been researching the SK correspondence of the 1840s. It gives many new insights into economic and social conditions in Ireland during the decade of the great famine, and into the operation of Ireland’s most important land agency during those years. It is intended ultimately to publish details on several of the estates managed by SK in a study more comprehensive than the present article, in book form. The proposed title is Landlords, tenants, famine: business of an Irish land agency in the 1840s, a draft of which has now been completed. A majority of the letters in that study are on themes some of which one might expect - rents, distraint (seizure of assets in lieu of rent); ‘voluntary’ surrender of land in return for ‘compensation’ upon quitting quietly; formal ejectment (a matter of last resort on estates managed by SK); landlordassisted emigration (on a scale much more extensive than most historians of Ireland in the 1840s appear to believe); petitions from tenants; complaints by tenants, both about other tenants and about local agents; landlord-financed and other relief of distress both before and during the great famine; major works of improvement (on almost all of the estates managed by SK which have been investigated in detail in the draft book); applications by SK, on behalf of landlords, for government loans to finance improvements; recommendations of agricultural advisers hired by SK, etc. Thus, most of the SK correspondence is about aspects of estate management. But the firm of SK was not only a manager of land. The correspondence reveals only two estates in Kildare, each of them relatively small, managed by SK in the 1840s. These were the lands of the Sherlocks near Naas and of Jane Coleman in the Kilcullen district. The correspondence on these properties differs substantively from most of those discussed in detail in the draft of Landlords, tenants, famine: first, it is relatively small in quantity, and secondly, it contains relatively little on the core aspects of estate management indicated above. Much of that on the Sherlocks focuses on misfortunes among family members, while the correspondence on Jane Coleman highlights the benevolence of that proprietor.
Gambling among Oregon incarcerated
No full textJeffrey Marotta, Ph.D., Problem Gambling Solutions, Inc., Tyree Dingle, M.S., Pacific University.Title from PDF cover (viewed on August 25, 2021).This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 34-38).Research support was provided by Problem Gambling Solutions, Inc. under contract number 146824.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
R. V. Dingle Ostracod Collection: Natural History Museum, London
No full textThe collection was donated to the Natural History Museum (NHM) between 2009 and 2011 and consists of 2534 slides. It comprises mainly marine ostracods of Jurassic to Holocene age from southern Africa (and its adjacent oceans), Antarctica and New Zealand. There is also a small collection of Quaternary non-marine ostracods from southwestern Africa, two sets of DSDP/ODP ostracods from the Southern Ocean, and one set of Cape Roberts Drilling Project (CRDP) ostracods from Victoria Land, East Antarctica. The individual slides in this collection have been computer registered. Further details of these can be found by inputting seach criteria based on information given in the paper to the NHM’s on-line catalogue at http://www.nhm.ac.uk/research-curation/collections/departmental-collections/palaeontology-collections/search/index.php.© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 4.0 License.NHM Repositor
Altruism as a Signal of Status
No full textTitle: Altruism as a Signal of Status, Author: Greg Dingle, Location: ThodeFrom an evolutionary point of view, it is difficult to explain the existence
of altruism that is not directed at kin or at friends. But humans
demonstrate this form of altruism commonly, in such ways as donating to
charity or heroically saving another's life. One explanation of these
behaviours that is still consistent with evolutionary theory is the idea that
altruism may function as a signal. Altruists gain a positive reputation
through their deeds that may ultimately return to increase their biological
fitness. Here I test this idea in a variety of ways, focusing on altruism as a
signal of status. In the laboratory, I conducted an experiment where
participants had the incentive to signal their personal wealth to others. In
another experiment, I manipulated participants' relative status in an
attempt to reduce costly conflict between participants. Outside the
laboratory, I investigated the connection between heroism and
reproductive success through a sample of WWI heroes. The background,
methods, and conclusions of these studies are detailed within.ThesisMaster of Science (MS
Having a lot of a good thing: multiple important group memberships as a source of self-esteem.
No full textCopyright: © 2015 Jetten et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedMembership in important social groups can promote a positive identity. We propose and test an identity resource model in which personal self-esteem is boosted by membership in additional important social groups. Belonging to multiple important group memberships predicts personal self-esteem in children (Study 1a), older adults (Study 1b), and former residents of a homeless shelter (Study 1c). Study 2 shows that the effects of multiple important group memberships on personal self-esteem are not reducible to number of interpersonal ties. Studies 3a and 3b provide longitudinal evidence that multiple important group memberships predict personal self-esteem over time. Studies 4 and 5 show that collective self-esteem mediates this effect, suggesting that membership in multiple important groups boosts personal self-esteem because people take pride in, and derive meaning from, important group memberships. Discussion focuses on when and why important group memberships act as a social resource that fuels personal self-esteem.This study was supported by 1. Australian Research Council Future Fellowship (FT110100238) awarded to Jolanda Jetten (see http://www.arc.gov.au) 2. Australian Research Council Linkage Grant (LP110200437) to Jolanda Jetten and Genevieve Dingle (see http://www.arc.gov.au) 3. support from the Canadian Institute for Advanced Research Social Interactions, Identity and Well-Being Program to Nyla Branscombe, S. Alexander Haslam, and Catherine Haslam (see http://www.cifar.ca)
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