ABSTRACT
Instron Residual Seal Force (IRSF) of glass vial/rubber closure systems was determined using an Instron 4501 Materials Testing System. Computer programs were written to process raw data and calculate IRSF values. Preliminary experiments indicated both the appearance of the stress-deformation curves and precision of the derived IRSF values were dependent on the internal dimensions and top surface geometry of the cap anvil. Therefore, a series of five cap anvils varying in shape and dimensions were machined to optimize performance and precision. Vials capped with West 4416/50 PURCOAT button closures or Helvoet compound 6207 lyophilization closures were tested with each cap anvil. Cap anvils with spherical top surfaces and narrow internal dimensions produced more precise results and more uniform stress-deformation curves than cap anvils with flat top surfaces and wider internal dimensions.
Subject(s)
Computer-Aided Design , Drug Packaging/methods , Electronic Data Processing , Equipment Design , Evaluation Studies as Topic , Freeze Drying , Models, Theoretical , Stress, MechanicalABSTRACT
The relevance of world system/dependency theory, and ecological-evolutionary theory for the population processes of currently developing nations is explored and evaluated by testing hypotheses drawn from models of fertility and fertility decline implied by them. Despite the preliminary and necessarily limited nature of the tests and measures, some support is found for hypotheses drawn from boh perspectives. Techno-economic heritage is found to affect fertility change directly, and world system status and techno-economic heritage are each found to affect fertility level and fertility change through independent effects on intervening variables. In addition, a significant interaction effect of techno-economic heritage and world system status on fertility level is found.
Subject(s)
Birth Rate , Developing Countries , Fertility , Research Design , Research , Statistics as Topic , Systems Analysis , Demography , Family Planning Services , Infant Mortality , Models, Theoretical , Mortality , Population , Population Dynamics , Social Change , Social PlanningABSTRACT
PIP: The current study departs from existing analyses by examining change in crude birthrates in a large sample of societies spanning all levels of development and by considering the effects of changes in independent variables on unit changes in fertility rates. It tests for the effects of levels and changes in female labor force representation and for effects of levels and changes in variables derived from classic demographic transition theory -- energy consumption per capita and child mortality. Additionally, it considers the possibility that these variables have differing impacts in least-developed (periphery) and developing (semiperiphery) nations than they had in already developed (core) nations. Data on dependent and independent variables were obtained from tables compiled by the World Bank (1980). In the 1st stage of the analysis, associations between coterminous trends in the dependent and independent variables were examined. To measure trends in fertility between 1960-77 the 1960 crude birthrates were sXrtracted from 1977 crude birthrates. Also obtained from the World Tables were child mortality rates (ages 1-4), female labor force representation (females per 100 persons in the labor force), and energy consumption per capita for both 1960 and 1977. Energy consumption per capita was chosen as the indicator of general development. Both 1960 values and changes between 1960 and 1977 were used as independent variables in the analysis. The blocks derived by Snyder and Kick (1979) were used to assign nations to either the core, semiperiphery, or periphery of the world system. It was possible to classify 93 of the original 100 cases, meaning only 7 cases were excluded in the analyses of subgroups. In the 2nd stage of the analysis, associations between fertility change and lagged changes in its proposed determinants were examined. Analysis of coterminous trends allowed for determining if overall trends in the dependent and independent variables were associated. All 3 theories underlying the hypotheses on causes of fertility change -- demographic transition theory, Caldwell's (1978) revision of the latter as it would be reflected in the economic status of women, and world system theory -- received some support, but it is argued that the evidence from the indirect test of Caldwell's theory of fertility decline was mixed, second, that a number of the results converged in their support for demographic transition theory, and third, that the overall pattern of findings failed to correspond well with expectations based on world system's theory.^ieng
