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A methodology was developed to correlate field life with observed degradation for electronics modules. This procedure was developed by identifying common deterioration characteristics in field units, modeling observed trends and then developing a model to predict future deterioration trends. This particular method focused on the deterioration of solder joint strength due to solder fatigue and comparing these values with a threshold based on known electrical failures. A conditional probability density function was formulated and quantified for both random shear strength and the minimum shear strength within a module. The conditional probability density function characterized both the changing mean and variance for a normally distributed random shear strength. With this methodology, time or mileage (life) prediction is based on the probability that the minimum performance response is less than a defined failure threshold. The methodology described herein promises to be an effective product development tool as the effect of design changes on product life can be more quickly and easily evaluated. While the technique developed herein is applicable to all electronic designs, the method was developed with a particular focus on understanding these relationships for automotive (harsh environment) applications.

The solder joint reliability of ceramic chip resistors assembled to laminate substrates has been a long time concern for systems exposed to harsh environments. In this work, the thermal cycling reliability of several 2512 chip resistor lead‐free solder joint configurations has been investigated. In an initial study, a comparison has been made between the solder joint reliabilities obtained with components fabricated with both tin‐lead and pure tin solder terminations. In the main portion of the reliability testing, two temperature ranges (−40‐125°C and −40‐150°C) and five different solder alloys have been examined. The investigated solders include the normal eutectic Sn‐Ag‐Cu (SAC) alloy recommended by earlier studies (95.5Sn‐3.8Ag‐0.7Cu), and three variations of the lead‐free ternary SAC alloy that include small quaternary additions of bismuth and indium to enhance fatigue resistance.

Recently, an intermittent hot-pressing process had been developed and applied to produce bamboo bundle laminated veneer lumber (BLVL) joints with lengths of more than 6 m. According to our previous studies, there was a major difference in the physical and mechanical performance of hot-pressing joints and at adjacent positions on the lumber. In this paper, heat transfer and the effects of various aging temperatures on the mechanical performance of the joints of intermittent hot-pressed BLVLs were studied. During the hot-pressing process, there were noticeable different temperature changes on the board. In addition, degradation of the modulus of elasticity (MOE) and modulus of rupture (MOR) values on the joints was greater than that on the adjacent positions of the BLVLs, and the degradation increased with increasing aging temperature. Because of the low interfacial bonding strength of the joints caused by the pre-curing effect during the hot-pressing process, the MOR was more sensitive to hydrothermal conditions. Therefore, when BLVLs produced by intermittent hot-pressing are used as engineering components, the joints should be well-designed and arranged to avoid being used in the same cross-section.

We conducted an economic comparison of oral sumatriptan with oral caffeine/ergotamine in the treatment of patients with migraine. Cost-effectiveness, cost-utility and cost-benefit analyses were conducted from societal and health-departmental perspectives. A decision tree was used. Utilities were assigned to health states using the Quality of Well-Being Scale. Simple and probabilistic sensitivity analyses were also carried out. From a societal perspective, using sumatriptan instead of caffeine/ergotamine resulted in an incremental cost-effectiveness ratio of -25 Canadian dollars ($Can) per attack aborted, an incremental cost-utility ratio of -$Can7507 per quality-adjusted life-year (QALY), and a net economic benefit of $Can42 per patient per year (1995 values). From the perspective of the health department, the incremental cost-effectiveness ratio was $Can98 per attack aborted, the incremental cost-utility ratio was $Can29,366 per QALY; the grade of recommendation based on past decisions regarding health technology for adoption into health insurance plans was 'moderate'. Sensitivity analysis showed that the results were robust to relatively large changes in the input variables. The incremental health benefits obtained from using oral sumatriptan rather than oral caffeine/ergotamine were achieved at moderately acceptable incremental costs, if past decisions on the adoption of other health technologies are used as a guide.

This paper deals with pension fund investment in urban infrastructure projects. It is suggested that the potential returns (and risks) with such projects are significantly greater than fixed income products though they have long gestation periods like gilt-edge securities. Our argument begins with recent evidence collected from a Nippon Credit industry-sponsored research study of Australian infrastructure investment performance. Also analysed are the internal and external characteristics of various kinds of urban infrastructure projects, ranging from roads and bridges through to hospitals and urban development recognising that these characteristics are important in determining investors' likelihood of realising their expectations. It is shown that, notwithstanding the uncertainty endemic to these kinds of projects, a commonly desired form of financial intermediation is a formal contract binding the parties to one-another over the long-term (as much as twenty years or more). While no doubt valuable for many reasons, matching in effect the formal structure of bonds, it is suggested that these institutional structures can be more problematic than often understood once the world of short-term discrete contracts is left behind. At issue here is the management of these contracts given that investment performance is a function of both the level of management resources (relative to capital investment) and the expertise of those who operate such facilities over the long term.

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