Finite element modelling of crack detection tests

Four non-destructive tests for determining the length of fatigue cracks within the solder joints of a 2512 surface mount resistor are investigated. The sensitivity of the tests is obtained using finite element analysis with some experimental validation. Three of the tests are mechanically based and one is thermally based. The mechanical tests all operate by applying different loads to the PCB and monitoring the strain response at the top of the resistor. The thermal test operates by applying a heat source underneath the PCB, and monitoring the temperature response at the top of the resistor. From the modelling work done, two of these tests have shown to be sensitive to cracks. Some experimental results are presented but further work is required to fully validate the simulation results.

Assessing the performance of crack detection tests for solder joints

This paper presents both modelling and experimental test data to characterise the performance of four non-destructive tests. The focus is on determining the presence and rough magnitude of thermal fatigue cracks within the solder joints for a surface mount resistor on a strip of FR4 PCB. The tests all operate by applying mechanical loads to the PCB and monitoring the strain response at the top of the resistor. The modelling results show that of the four tests investigated, three are sensitive to the presence of a crack in the joint and its magnitude. Hence these tests show promise in being able to detect cracking caused by accelerated testing. The experimental data supports these results although more validation is required.

Managing alcohol related aggression in the emergency department (Part II)

Violence in the emergency department (ED) is a global problem. In our first paper, we highlighted the potential psychological effects of alcohol intoxication, the literatures discussion of alcohol related violence in the emergency department and the importance of developing positive nurse/service user relationships. In this second paper, we discuss personal and organisational strategies clinical nursing staff may consider appropriate to minimise the risk of assault when caring for service users projecting alcohol related aggression.

Managing alcohol related aggression in the emergency department (Part 1)

Internationally, violence in the emergency department (ED) is of a constant concern to emergency practitioners. Frequently, both original research papers and anecdotal reports emphasise the phenomenon of alcohol related aggression in the ED. In this first paper, we highlight the literatures discussion of alcohol related violence in the emergency department and the potential psychological effects of alcohol intoxication. In the second we offer personal and organisational strategies clinical nursing staff may consider appropriate to minimise the risk of assault when caring for service users projecting alcohol related aggression.