Microscopic Experimental Investigation on Shear Failure of Solder Joints

A microscopic investigation has been made on the shearing of one leaded and two lead-free solders by using an in situ SEM method. A shear lap joint specimen is designed and fabricated to accommodate a thin layer of solder alloy between copper strips. A non-contact method that measures strains in a very narrow area in the solder was applied. A laser grid was also used on the copper strip for measuring the back-face strain. Simultaneously micrographs at various stages were also taken. Where in situ measurements and micrographs are recorded they can reveal the continual development of damage and fracture mechanisms consistent with observations generated by low-cycle fatigue loading. This means that the shear test can be used as an alternative test to fatigue loading tests. By comparison, two lead-free solder specimens showed much smaller elongation to failure than the leaded solder, although all specimens showed similar sequence of events leading to final failure, including the boundary layer fracture phenomenon. The back-face strain indicator for the formation of a macro crack is due to the shifting of high stress concentration area from the joint-edge region to outside the joint region as revealed by a damage-coupled finite element procedure. The procedure also provides an estimate on the critical back-face strain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42763/1/10704_2004_Article_2311.pd

Comparing Dutch Case management care models for people with dementia and their caregivers: The design of the COMPAS study

<p>Abstract</p> <p>Background</p> <p>Dementia care in the Netherlands is shifting from fragmented, ad hoc care to more coordinated and personalised care. Case management contributes to this shift. The linkage model and a combination of intensive case management and joint agency care models were selected based on their emerging prominence in the Netherlands. It is unclear if these different forms of case management are more effective than usual care in improving or preserving the functioning and well-being at the patient and caregiver level and at the societal cost. The objective of this article is to describe the design of a study comparing these two case management care models against usual care. Clinical and cost outcomes are investigated while care processes and the facilitators and barriers for implementation of these models are considered.</p> <p>Design</p> <p>Mixed methods include a prospective, observational, controlled, cohort study among persons with dementia and their primary informal caregiver in regions of the Netherlands with and without case management including a qualitative process evaluation. Inclusion criteria for the cohort study are: community-dwelling individuals with a dementia diagnosis who are not terminally-ill or anticipate admission to a nursing home within 6 months and with an informal caregiver who speaks fluent Dutch. Person with dementia-informal caregiver dyads are followed for two years. The primary outcome measure is the Neuropsychiatric Inventory for the people with dementia and the General Health Questionnaire for their caregivers. Secondary outcomes include: quality of life and needs assessment in both persons with dementia and caregivers, activity of daily living, competence of care, and number of crises. Costs are measured from a societal perspective using cost diaries. Process indicators measure the quality of care from the participant’s perspective. The qualitative study uses purposive sampling methods to ensure a wide variation of respondents. Semi-structured interviews with stakeholders based on the theoretical model of adaptive implementation are planned.</p> <p>Discussion</p> <p>This study provides relevant insights into care processes, description of two case management models along with clinical and economic data from persons with dementia and caregivers to clarify important differences in two case management care models compared to usual care.</p

Development of the combined assessment of residential environments (CARE) profiles

Aim: This paper reports the development and initial testing of the combined assessment of residential environments (CARE) profiles, which identify the frequency of positive events over a specified time based on the perceptions of residents, relatives and staff in care home settings. Background: Despite the well-known benefits of positive events for subjective well-being, little is known about the nature of positive events experienced by residents, relatives and staff in care homes. There is also a dearth of tools capable of systematically evaluating how frequently these events occur in this context. Methods: The CARE profiles were developed and tested between February 2004 and June 2005 with a combined sample of 372 residents, relatives and staff drawn from 11 care homes. An Event Frequency Approach was adopted to create three questionnaires (residents, relatives and staff), each containing 30 consensually valid positive events. The thematic content of these events was balanced for each questionnaire using the Senses Framework as a theoretical model. Once completed, the CARE profiles were tested in four care homes. Results: Test data from the CARE profiles were used to produce a bar chart showing median frequencies of positive events experienced by residents, relatives and staff during the timeframe in question (e.g. 1 month). These profiles were shown to be internally consistent, with alpha scores ranging from 0·70 to 0·89 for residents, 0·91 to 0·94 for relatives and 0·78 to 0·92 for staff. Conclusion: We envisage that feedback from the CARE profiles will both reinforce good care home practice and identify areas for change based on the experiences of all major stakeholders. However, further development of the profiles is needed if the experiences of cognitively impaired residents are to be included in the assessment process.</p