Tribo-corrosion properties of cobalt-based medical implant alloys in simulated biological environments

Tribological problems and corrosion degradation have been recognized as essential risks for total joint replacements, especially for all-metal arthroplasty. Few studies have focused on the interactions between tribology and corrosion (tribocorrosion) for implant materials. This paper addresses the importance of understanding tribocorrosion and the evaluation of such materials in simulated biological environments. Due to the complex effect of proteins on tribocorrosion, which has been demonstrated in previous studies, this study focuses towards understanding the effects of amino acids as aspects of material degradation. Dulbecco’s Modified Eagle’s Medium (DMEM) is a cell culture solution. It contains comparable amount and types of amino acids to normal synovial fluid in human joints. 0.36% NaCl solution was employed to isolate the biological species. Three materials were tested; High carbon (HC) CoCrMo (contains 0.19% carbon), low carbon (LC) CoCrMo (widely used materials for total joint replacement) and stainless steel UNS S31603 (316L). Integrated electrochemical tests supported by measurement of friction and near surface chemical analysis were carried out to enable their tribocorrosion behaviour to be fully characterized. As a general conclusion, amino acids were found to react with materials under tribological contacts and form complex organometallic/oxides which lubricate the metallic sample surface. Tribocorrosion plays a very important role in material degradation in the studied environments. HC CoCrMo shows superior wear, corrosion and tribocorrosion resistance – the material characteristics and their effect on the different tribocorrosion processes are discussed

Domestic UK retrofit challenge: Barriers, incentives and current performance leading into the green deal

Copyright @ 2012 Elsevier - The official published version can be accessed from the link below.This paper reviews the thermal performance of the existing UK housing stock, the main fabric efficiency incentive schemes and the barriers to obtaining deep energy and CO2 savings throughout the stock. The UK faces a major challenge to improve the thermal performance of its existing housing stock. Millions of dwellings possess ‘hard-to-treat’ solid walls and have glazing which is not cost effective to improve. A range of fabric efficiency incentive schemes exist, but many do not target the full range of private and social housing. From now on, the Green Deal will be the UK's key energy efficiency policy. However, the scheme is forecasted to have low consumer appeal and low incentives for investors. Moreover, calculated Green Deal loan repayments will be reliant upon estimated energy savings, yet it is claimed that retrofit measures may only be half as effective as anticipated due to a lack of monitoring, poor quality installation and the increased use of heating following refurbishment. Looking to Germany, there has been success through the Passivhaus standard, but the UK currently lacks appropriate skills and cost effective components to replicate this approach. In addition, the embodied energy in retrofit products and materials threatens to counter operational savings.This study is funded by the EPSRC, Brunel University and Buro Happold Ltd

National Evaluation of the Capacity Building Programme in English Local Government: Annex 4: Follow On Study of Progress in Seven Case Study Improvement Partnerships

This report is one of a series of outputs from the national evaluation of the Capacity Building Programme for local government in England (CBP), being undertaken by a team of researchers at the Policy Research Institute (PRI) at Leeds Metropolitan University and the Cities Research Unit at the University of West of England. This report summarises the findings from the second phase of fieldwork with regional and sub-regional Improvement Partnerships, established to facilitate capacity building and improvement activity in local authorities. The research underpinning this report was undertaken in seven case study Improvement Partnerships (see Section 2) in October and November 2006 and follows a similar – baseline – exercise undertaken during the same period during 2005. It thus both draws on the earlier research (see Section 3) and identifies evidence of progress and impact (see Section 10) since the baseline phase

National Evaluation of the Capacity Building Programme in English Local Government: Annex 1. Seven Case Studies: The Pilot Programme

This report presents the findings of the evaluation of the Capacity Building pilots. The evaluation of the pilots is part of the on-going evaluation of the Capacity Building Programme and has been undertaken in the early scoping phase of the main evaluation in order to capture key learning points and insights into the programme. It is intended that the ongoing evaluation of the Capacity Building Programme will be formative and assist in the development of the programme over time. In what follows the background to the pilots programme is discussed, highlighting the kinds of capacity building activities the pilots are engaged with and the link between the Capacity Building Programme and the CPA. The report outlines the structure and purpose of the pilots programme and the nature and characteristics of the different pilots that were undertaken. The seven case studies are then discussed in more detail in the main body of 1 Introduction | 5 the report. These are drawn together in key themes and findings which can be used to strengthen future project development

National Evaluation of the Capacity Building Programme in English Local Government: Overall Final Report

This report is one of a series of outputs from the National Evaluation of the Capacity Building Programme for local government in England (CBP), undertaken by a team of researchers at the Policy Research Institute (PRI) at Leeds Metropolitan University and the Cities Research Unit at the University of West of England. This report summarises the findings from all four key strands of the evaluation. Because of the difficulties associated with quantifying the capacity of local authorities, much less the sector, in relation to the dynamic roles and objectives that they pursue, the report focuses on what has worked, why and in what circumstances, rather than providing a definitive assessment of the extent of change of capacity building enabled by the CBP. The CBP was launched in 2003 as a joint Department for Communities and Local Government/Local Government Association (LGA) initiative to support capacity building and improvement activities within local authorities in England. The CBP has supported four main streams of improvement and capacity building activity in local authorities (see Section 1.2; p13)

Botulinum toxin-A for the treatment of overactive bladder: UK contributions

Background: Botulinum toxin-A (BoNT/A) is now established second-line management for refractory overactivebladder (OAB) and recognised in many incontinence guidelines and pathways. For those with neurogenic detrusoroveractivity secondary to spinal cord injury or multiple sclerosis, the toxin is currently licensed in certain parts of theworld, including the UK. It is an effective treatment in those in whom antimuscarinics and conservative measures havefailed who have symptoms of OAB and or detrusor overactivity (DO). Methods: Treatment can be given in an outpatient setting and can be administered under local anaesthesia. Its efficacylasts for between six and 12 months. Results: It has an acceptable safety profile with the biggest risk being urinary tract infection and difficulty emptying thebladder, necessitating clean intermittent self-catheterisation (CISC). Medium-term follow-up suggests repeated injectionsare also safe and efficacious. Conclusions: The mechanism of action of the toxin is more complicated than originally thought, and it seems likelythat it affects motor and sensory nerves of the bladder. In the last 10 years much of the progress of this treatment fromearly experimental trials to mainstream clinical use, and a better understanding of how it works in the bladder, are as aresult of research conducted in the UK. This review summarises the significant and substantial evidence for BoNT/A totreat refractory OAB from UK centres. © British Association of Urological Surgeons 2013

The Effect of Microseparation on Corrosion Rates of Metal-on-Metal Total Hip Replacements

The poor performance of Metal-on-Metal (MoM) bearings has to date been blamed on “adverse loading” conditions. Studies have focused on the effect of cup inclination and microseparation on gravimetric wear rates and highlighted the importance of surgical technique when implanting such devices. Up to four fold increase in the wear rates of MoM bearings subjected to microseparation has been reported during the bedding-in period. The contribution of corrosive processes to overall material degradation during adverse loading has not previously been investigated. In the present study 28 mm HC CoCrMo alloy Total Hip Replacements were tested to 1 Mcycles under standard gait and severe microseparation conditions in an electrochemically instrumented hip simulator. An order of magnitude increase in material lost as a result of oxidation was noted (0.234 to 2.044 mm3/Mcycle) during microseparation. Corrosive degradation may therefore be a much more significant contribution to poor bearing performance under adverse loading than previously considered

Removal processes for tributyltin during municipal wastewater treatment

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Springer.The fate and behaviour of tributyltin (TBT) at two wastewater treatment works was examined. Both sites had two inlet streams, and each utilised high rate biological filters (biofilters) on one the streams, before treatment of the combined flows on trickling filters, with one having additional tertiary processes, installed to remove ammonia and solids. The study was designed to determine if these processes enhanced the removal of TBT. Degradation of TBT was observed in one of the biofilters, possibly as a result of temperature and hydraulic loading. At the treatment works with tertiary processes, the mass flux showed the overall removal of TBT was 68 %, predominantly due to removal with solids in the primary settlement processes. However, overall removal of 95 % was observed in the conventional trickling filter works with 94 % of this due to biodegradation in the trickling filter. The two works both removed TBT, but at different treatment stages and by different processes. Differences in the form (solubility) of TBT in the influent may have attributed to this, although further understanding of factors controlling degradation would allow for a more complete assessment of the potential of biological processes to remove hazardous compounds from wastewaters.United Utilities PL