Accuracy of mercury-alloy proportioning systems.
To measure the reproducible accuracy of some commercially available mercury/alloy proportioning systems, a study was made of several mercury dispensers, alloy pellets, and disposable capsules. This study included a consideration of some human variables that were introduced in manipulating the systems. Most of the systems that were tested provided acceptable accuracy when used correctly.
Plasticity of Amalgam Mixes
The plasticity of an amalgam mix prior to and during condensation could have a significant influence on the homogeneity and adaptation of the amalgam restoration. One of the difficulties in investigating the possible significance of mix plasticity is the absence of a quantitative test to measure this property. Presently used tests include such subjective evaluations as rolling the amalgam mix into a rope, dropping the mix from a certain height to a flat surface, rolling the mix between the fingers, or sensing the way in which the mix behaves under forces of condensation. In view of the possible significance of mix plasticity, it was the purpose of this investigation to devise and evaluate a test to quantitate mix plasticity and to determine subsequently the influence of various factors on this property. No attempt was made at this time to determine either a value for optimum plasticity or a difference of plasticity that might be significant to the efficacy of the amalgam restoration. A study to demonstrate the true significance of the property of mix plasticity would necessarily follow the establishment of a valid test. Thus, the objective of this investigation was the development and evaluation of a plasticity test only.
The uprising of the marginalised: a socio-economic perspective of the Syrian uprising
More than three years after the outbreak of protests in a number of Arab countries, the role of socio-economic factors in these events is attracting more attention. One of the cases that needs more research is Syria. More than three years into the Syrian uprising, the socio-economic roots of the protest movement that became one of the bloodiest civil conflicts in the history of the Middle East need to be examined. While it has been observed that the Syrian uprising, contrary to some ‘Arab Spring’ countries, has been an uprising of more marginalised social groups with a strong role played by poorer segments in the society, particularly rural and rural-to-urban migrants, the socio-economic explanation for this is still underdeveloped. This paper aims at contributing to a better understanding of this issue by examining the political and socio-economic compromise that underlined the rule of the Ba’th party in Syria for four decades and unpacking how a combination of internal and external shifts that started in the 1990s and intensified in the 2000s led to the erosion of this compromise, providing the background to the events that began in 2011.