Opiate Prescription Practices and VPMS Use: Impacts of the Vermont Prescription Monitoring System

Introduction. Our project assessed prescriber use of the Vermont Prescription Monitoring System (VPMS) and collected suggestions for its improvement, and for reducing opiate diversion.https://scholarworks.uvm.edu/comphp_gallery/1083/thumbnail.jp

Characterisation of lead pipes used in the water industry: extrusion processing, alloy microstructure and their role in service failures

The issue of leakage within the water distribution system is one of importance not only at an economic level for the industry, but also as a result of an environmental agenda addressing issues of water sustainability. The present work is concerned with leakage from lead based assets, in particular distribution pipes. Very little is known about the failure mechanisms within lead based assets. The present paper presents the findings from a study in which lead samples from intact and failed pipes, sourced from the Thames Water area, have been examined. The failure mechanisms have been identified at the macroscopic level and the pipe microstructure has been characterised -aspects of the microstructure control particular properties of the pipe (e.g. strength, creep and fatigue behaviour) and so may contribute to the potential failure modes. The present study is the first stage in a programme of work designed to develop a better understanding of the failure modes in lead assets, leading to the formulation of a more effective condition assessment model

WEIBULL BASED METHODOLOGY FOR CONDITION ASSESSMENT OF CAST IRON WATER MAINS AND ITS APPLICATION

Abstract A qualitative and quantitative understanding of how cast iron water distribution pipes fail in service would facilitate a targeted approach to the management of rehabilitation in the water industry. This paper proposes a technique for assessing the condition of pipes, based on strength characteristics obtained from small samples; this offers an alternative way of estimating the likelihood of failure to current methodologies based on pit-depth measurements. Examination of recovered pipe samples indicates that the strength of the cast iron pipe reduces over time as a result of corrosion, although other time-dependent processes, such as fatigue, may also contribute to this degradation. Taken with previous work, this paper suggests that the variation in strength of small samples removed from cast iron water distribution pipes can be characterised using Weibull methods. It is argued that the Weibull modulus provides a useful indicator of the condition of the pipe. Using scaling arguments, inherent in the Weibull methodology, it is then possible to use data from small samples to predict the likely strength characteristics of water distribution pipes in the ground, which is reasoned to be a good measure of the potential performance of the pipe in service. The Weibull approach is applied to a number of different data sets obtained from testing samples extracted from a range of pipes, which have seen service at various locations in the Thames Water region. One of these data sets was from locations where failure had occurred in service. It is shown that the use of Weibull analysis can identify pipes in the network that have degraded the most significantly. A methodology is suggested whereby this information taken with other performance indicators can be used to identify the local regions where rehabilitation is required most urgently. Alternatively it can be used to identify those regions of the network which are in good condition and unlikely to need repair or replacement work

Properties and performance of recycled aggregates

The research work reported was carried out in 1987 as part of a four-year programme sponsored in part by the Institute of Demolition Engineers on the recycling of demolition debris. The physical and mechanical properties of crushed concrete and demolition debris from a variety of sources were examined to assess the suitability of these aggregates for use as granular sub-base materials. In particular, sieve analyses and compacted density tests were conducted, during the construction of a road in Portsmouth, to compare the use of crushed concrete and limestone as the upper part of the capping layer. The authors review recent research on the recycling of crushed aggregates, examining their physical and mechanical properties and gauging their suitability as sub-base materials for roads