White Rose Research Online
Este es el repositorio institucional de tres universidades del Reino Unido (York, Leeds y Sheffield), creado con el apoyo de SHERPA. Proporciona acceso a los artículos de investigación de las instituciones.
Status = In Press
Mostrando recursos 1 - 20 de 671
Creep curve measurement to support wear and adhesion modelling, using a continuously variable creep twin disc machine - Fletcher, D. I.; Lewis, S.
Predictive modelling of wear and adhesion at rolling-sliding contacts such as a railway rail and wheel depends on understanding the relationship between slip and shear force at the contact surface, i.e. the creep verses force curve. This paper describes a new approach to creep curve measurement using a twin disc machine running with a continuous programmed variation of creep, enabling an entire creep curve to be defined in a single experiment. The work focuses on very low levels of creep, ranging from zero to 1%, and shows clear correlation between the creep curve gradient and the full slip friction coefficient...
A new two-dimensional model of rolling-sliding contact creep curves for a range of lubrication types - Fletcher, D. I.
Experimentally determined creep curves for rolling-sliding contact in lubricated conditions are found to deviate greatly from the standard theory for two body contact. This paper presents a new model to represent coefficient of adhesion (also known as traction coefficient) and creep based on experimental data gathered for a range of railway rail-wheel contact conditions. The model developed is based on a 2D elastic foundation representation of a twin disc contact. This is used to quantify the creep curves in a similar manner to existing 3D models of real rail-wheel contacts undergoing partial slip for a range of lubrication conditions.
How to measure quality of life for cost effectiveness analyses in personality disorders? A systematic review. - Papaioannou, D.; Brazier, J.; Parry, G.
Objective: To assess the construct validity and responsiveness of four generic health related quality of life (HRQL) measures in personality disorders (PDs).
Methods: A systematic review was undertaken. Ten databases were searched and reference lists scrutinised to identify relevant studies. Relevant data were extracted accordingly. A narrative synthesis was performed of the evidence on construct validity including known groups validity (detecting differences in HRQL scores between two different groups), convergent validity (strength of association between generic HRQL and other measures (e.g. symptom) and responsiveness (differences in generic HRQL measure scores in responders/non-responders or correlation with changes in other measures).
Enhancing microbial iron reduction in hyperalkaline, chromium contaminated sediments by pH amendment - Whittleston, RA; Stewart, DI; Mortimer, RJG; Burke, IT
Soil collected from beneath a chromite ore processing residue (COPR) disposal site contained a diverse population of anaerobic alkaliphiles, despite receiving a continuous influx of a Cr(VI) contaminated, hyperalkaline leachate (pH 12.2). Chromium was found to have accumulated in this soil as a result of an abiotic reaction of Cr(VI) with Fe(II) present in the soil. This sediment associated Fe(II) was therefore acting as a natural reactive zone beneath the COPR and thereby preventing the spread of Cr(VI). In anaerobic microcosm experiments soil microorganisms were able to reduce nitrate at pH 11.2 coupled to the oxidation of electron donors derived...
Towards an agenda for post-carbon cities: Lessons from LILAC, the UK's first ecological, affordable, cohousing community - Chatterton, P
This paper explores an agenda towards post-carbon cities, extending and deepening established debates around low-carbon, sustainable cities in the process. The label post-carbon builds upon issues beyond those of greenhouse gas (GHG) emissions, energy conservation and climate change, adding a broader set of concerns including economic justice, behaviour change, wellbeing, land ownership, the role of capital and the state, and community self management. The paper draws upon a case-study of an embryonic post-carbon initiative due for completion in 2013 called Lilac. Based in Leeds, Lilac stands for Low Impact Living Affordable Community and is the first attempt to build an...
The stewardship of things: Property and responsibility in the management of manufactured goods - Lane, R.; Watson, M.
In the context of broad-based concerns about the need to move towards a more sustainable materials economy, particularly as they are expressed in debates around ecological modernisation (EM), we argue that product stewardship has radical potential as a means to promote significant change in the relationship between society and the material world. We focus on two important dimensions that have been neglected in approaches to product stewardship to date. Firstly, we argue that immanent within the basic concept of stewardship is a problematisation of dominant understandings of property ownership in neoliberal market economies. In the space opened up by notions...
On the Willingness to Pay for Rural Rail Service Level Changes - Johnson, DH; Nash, C; Jackson, J
In the context of current plans for public sector expenditure, cuts in the provision of regional and rural rail services may be under consideration. We show how it is possible to assess the values of different aspects of rural rail services to aid quantitative appraisal and management decision-making. To this end we conduct an SP experiment which values the provision of different levels of rural rail services and compares them with the values held for a replacement bus or coach service. While a number of studies have examined the field of rural rail services in the UK, and other studies...
Modelling of segmentation-driven vibration in machining - Taylor, C M; Turner, S; Papatheou, E; Sims, N D
Excessive vibration, such as chatter, is a common problem in machining processes. Meanwhile, numerous hard, brittle metals have been shown
to form segmented chips, also known as sawtooth chips, during machining.
In the literature, a cyclic cutting force has been demonstrated where
segmented chips are formed, with the force cycle corresponding to
the formation of segments. Segmented chip formation has been shown
to be linked to high vibration levels in turning and milling processes.
Additionally, it has been proposed that the amplitude of chatter
vibrations can be limited by interference between the tool flank
and wavy workpiece surface, a phenomenon known as tool-flank process
damping. In this contribution, a model...
A finite element method for active vibration control of uncertain structures - Morales, A.L.; Rongong, J.A.; Sims, N.D.
This work introduces a fuzzy design method using the finite element procedure to simulate and analyze active vibration control of structures subjected to uncertain parameters. The purpose of this work is to provide a tool for studying the influence of uncertainty propagation on both stability and performance of a vibration control system, whilst avoiding the need for computationally expensive probabilistic methods or complex robust control techniques. The proposed procedure applies a general and efficient strategy for computing fuzzy results to a sequence of finite element calculations. Finally, the applicability of the methodology is illustrated through some realistic case studies related...
The Return of Class War Conservatism? Housing under the UK Coalition Government - Hodkinson, SN; Robbins, G
The May 2010 election of a Conservative-dominated UK Coalition Government unleashed an unprecedented austerity drive under the auspices of “deficit reduction” in the wake of the global financial crisis. This article focuses on housing policy to show how the “cuts” are being used as an ideological cover for a far-reaching, market-driven restructuring of social welfare policy that amounts to a return of what Ralph Miliband called “class war conservatism”. We revisit the main ideological contours and materialist drivers of Thatcherism as a hegemonic strategy, discussing the central role played by housing privatisation in the neoliberal project that was continued, but...
Common scale valuations across different preference-based measures: estimation using rank data. - Alava Hernández, M,; Brazier, J,; Rowen, D,; Tsuchiya, A,
Background: Different preference-based measures (PBMs) used to estimate Quality Adjusted Life Years (QALYs) provide different utility values for the same patient. Differences are expected since values have been obtained using different samples, valuation techniques and descriptive systems. Previous studies have estimated the relationship be- tween pairs of PBMs using patient self-reported data. However, there is a need for an approach capable of generating values directly on a common scale for a range of PBMs using the same sample of general population respondents and valuation technique but keeping the advantages of the different descriptive systems.
Stonework - Edmonds, Mark Roland; Ferraby, Rose
A book exploring alternative narrative forms for understanding prehistoric stoneworking
Palestinians in Jordan : The Politics of Identity - Gandolfo, Luisa
The Palestinian community places Jordan in the unique demographical position of holding a minority stake in citizenship. In times of unrest the ratio is estimated at 80% Palestinian-Jordanian and 20% Jordanian; in peacetime, this is reduced to 50% for each. Accordingly, the dynamic between the communities is subject to political change, economic climate, the application and abrogation of human rights and the extent of integration achieved. Approaching from the perspective of political identity, the study differs from alternative publications in the field of Palestinian and Jordanian studies by affording an contemporary, provocative exploration of the legacies of the British Mandate,...