CONTEXT Understanding shifts in contraceptive method mix is key to helping policymakers, program managers and donor agencies meet current contraceptive demand and estimate future needs in developing countries. METHODS Data from Demographic and Health Surveys, Reproductive Health Surveys and other nationally representative surveys were analyzed to describe trends and shifts in method mix among...

the strength of concrete is a function of the proportions of the constituent materials, namely, cement, water, fine and coarse aggregates. the conventional methods used to determine the mix proportions that will yield the desired strength, are laborious, time consuming and expensive. in this paper, a mathematical method based on modified regression theory is formulated for the prediction of con...

Concrete mix design by the ACI method requires various material properties as the input. The effect of variation of these input parameters on mix proportions has been studied here, with reference to strength attainment in few cases. The sensitivity of the mix has been expressed by volume ratios of fine aggregate to coarse aggregate and cement to fine aggregate. It is found that inter-particle v...