No abstract

Limits of detection have been studied for several elements in aluminium and steel alloys, at atmospheric pressure in air, by use of the single and collinear double-pulse configurations of laser-induced breakdown spectroscopy. For this purpose, calibration plots were constructed for Mg, Al, Si, Ti, Cr, Mn, Fe, Ni, and Cu using a set of certified aluminium alloy samples and a set of certified steel samples. The investigation included optimization of the experimental conditions to furnish the best signal-to-noise ratio. Inter-pulse delay, gate width, and acquisition delay were studied. The detection limits for the elements of interest were calculated under the optimum conditions for the double-pulse configuration and compared with those obtained under the optimum conditions for single-pulse configuration. Significantly improved detection limits were achieved, for all the elements investigated, and in both aluminium and steel, by use of the double-pulse configuration. The experimental findings are discussed in terms of the measured plasma conditions (particle and electron density, and temperature).

Background: Breastfeeding and proper weaning contribute to achievement of the Sustainable Development Goals. In Egypt, by age 4-5 months, only 13% of infants are exclusively breastfed. A survey conducted in Egyptian hospitals concluded that many of the 10 steps to support successful breastfeeding were not executed correctly and other steps were not executed at all. Aims: To explore the patterns of feeding and weaning among infants in Egypt, and identify their determinants, to improve practice and promote children's nutritional status. Methods: A cross-sectional analytical study of 333 mother-infant pairs attending two primary healthcare (PHC) centres for vaccination sessions between April 2017 and June 2018. Mothers were interviewed using a structured questionnaire. Results: Almost all infants were born in hospitals. Exclusive breastfeeding was not widely practiced. Prelacteal feeding was a common malpractice. The majority of mothers initiated artificial feeding during the first month of life. Rural mothers tended to introduce different foods earlier than urban mothers did. Minimum dietary diversity was achieved by 50.9% of urban infants aged ≥ 6 months (≥ 4 food groups), compared with 25.9% of rural infants. Minimum recommended meal frequency for age was fulfilled for 51.9% of urban and 29.6% of rural infants. More than 85% of mothers expressed their need for additional knowledge, and more than half identified the PHC centre as the appropriate source for information. Conclusions: Our study reflects deficiency in maternal practice regarding breastfeeding and weaning, despite being regular visitors to the PHC centre.