Key performance indicators – A new approach for specifying concrete and assessing state of health of concrete structure

The focus of this paper is to outline a method for consolidating and implementing the work on performance-based specification and testing. First part of the paper will review the mathematical significance of the variables used in common service life models. The aim is to identify a set of significant variables that influence the ingress of chloride ions into concrete. These variables are termed as Key Performance Indicators (KPI’s). This will also help to reduce the complexity of some of the service life models and make them more appealing for practicing engineers. The second part of the paper presents a plan for developing a database based on these KPI’s so that relationships can then be drawn between common concrete mix parameters and KPI’s. This will assist designers in specifying a concrete with adequate performance for a particular environment. This, collectively, is referred to as the KPI based approach and the concluding remarks will outline how the authors envisage the KPI theory to relate to performance assessment and monitoring.

An evaluation of palliative care services for cancer patients in the Southern Health and Social Services Board of Northern Ireland.

An interview study of 55 lay carers of people who died from cancer in the Southern Board of Northern Ireland was undertaken using a combination of closed-format and open-ended questions. The aim of the study was to evaluate palliative care services delivered in the last six months of their lives to cancer patients who died either at home or in hospital. Two-thirds of the deaths (36) occurred in the domestic home, 45 of the deceased were admitted as hospital inpatients, and the great majority were in receipt of community nursing (53) and general practitioner (54) services. Open-ended questions were used to allow respondents to give their views about services in some detail and their views about good and bad aspects of services were sought. While they were generally satisfied with services specific areas of difficulty were identified in each aspect of care addressed by the study. The most favourable assessments were made of community nursing with the greatest number of negative comments being made about inpatient hospital care. Differing interests between some of those who were dying and their lay carers were found in two areas: the receipt of help from nonfamily members and the information that the deceased received about their terminal status.

State detection of bond wires in IGBT modules using eddy current pulsed thermography

Insulated gate bipolar transistor (IGBT) modules are important safety critical components in electrical power systems. Bond wire lift-off, a plastic deformation between wire bond and adjacent layers of a device caused by repeated power/thermal cycles, is the most common failure mechanism in IGBT modules. For the early detection and characterization of such failures, it is important to constantly detect or monitor the health state of IGBT modules, and the state of bond wires in particular. This paper introduces eddy current pulsed thermography (ECPT), a nondestructive evaluation technique, for the state detection and characterization of bond wire lift-off in IGBT modules. After the introduction of the experimental ECPT system, numerical simulation work is reported. The presented simulations are based on the 3-D electromagnetic-thermal coupling finite-element method and analyze transient temperature distribution within the bond wires. This paper illustrates the thermal patterns of bond wires using inductive heating with different wire statuses (lifted-off or well bonded) under two excitation conditions: nonuniform and uniform magnetic field excitations. Experimental results show that uniform excitation of healthy bonding wires, using a Helmholtz coil, provides the same eddy currents on each, while different eddy currents are seen on faulty wires. Both experimental and numerical results show that ECPT can be used for the detection and characterization of bond wires in power semiconductors through the analysis of the transient heating patterns of the wires. The main impact of this paper is that it is the first time electromagnetic induction thermography, so-called ECPT, has been employed on power/electronic devices. Because of its capability of contactless inspection of multiple wires in a single pass, and as such it opens a wide field of investigation in power/electronic devices for failure detection, performance characterization, and health monitoring.