Infant and Young Child Feeding Practices among Mothers in Lahore, Pakistan: A Cross-Sectional Study

Background: Inadequate child feeding practices lead to malnutrition, higher under-five mortality rates and adverse effects on quality of life. This study aimed to assess the breastfeeding and complementary feeding practices of mothers as well as the influence of various sociodemographic factors on them in local families of Lahore. Methods: This is a cross-sectional, descriptive study. It was conducted in CMH (Combined Military Hospital), Lahore in 2018. It comprises a sample of 203 mothers with children of at least two years of age, from various urban areas of Lahore. The subjects were selected on the basis of the inclusion criteria. Mothers with psychiatric illnesses and children with congenital anomalies were excluded from the study. Mothers were approached in the paediatric outpatient departments of four tertiary care hospitals of Lahore. Responses were recorded using a modified version of the Action Contre La Faim (ACF) questionnaire. Independent sample t-test and chi-square test were applied for analysis of the data. Results: Early initiation of breastfeeding within one hour from birth was observed in 83.3% children. Most children were administered colostrum (69.5%). The rate of exclusive breastfeeding for the first six months was 45.3%.  A child was being breastfed 8.21 ± 6.67 (mean ± SD) times a day. Maternal educational status, total number of adults in a household, and access to free healthcare were identified as important factors influencing the practice of breastfeeding. Porridge, khichdi, eggs, fruit and yoghurt were the most frequently used complementary foods. Conclusions: A high rate of an early start of breastfeeding and a low rate of exclusive breastfeeding for at least six months were predominant in our population. Administration of colostrum was observed in approximately two-thirds of the study participants. Education of the mother, type of the family system (nuclear or combined), and access to free healthcare strongly influence the breastfeeding practices.

Modeling of Damage Growth in Frp Composites With Stress Raisers Such As Holes and Notches

Fibre reinforced polymer composite panels are preferred in high performance structural panels because they are strong, stiff and light. Stress raisers such as holes or notches (for accessibility, mechanical joining, and routing of cables etc.) may be present in any engineering structure and composite structures are no exception. Theoretically, a stress raiser is simply a localization of high stress-strain concentrations quantified by the Stress Concentration Factor (SCF). It is well established in literature and engineering practice that stress-strain concentrations due to holes or notches, unless accompanied by local plastic strain hardening, reduce the apparent strength of the panels. Since SCF is a function of elastic properties of the material, so in isotropic materials, the SCF is defined with elastic SCF (entails elastic properties within the elastic range of material) and plastic SCF (entails elastic properties in the plastic range of material). However, literature is scarce of such definition for the case of anisotropic/orthotropic materials, where the SCF is also a function of its elastic properties. Contrary to isotropic homogenous materials, composite panels offer a very complex structure, where fibres are generally regarded as brittle which deform elastically to final failure exhibiting either slight or no linear deformation. Whereas matrices generally experience plastic deformation hence the failure strain in matrics is far higher than the fibres. Additionally, once a composite panel containing a hole is subjected to tensile loading, tangential stress at the periphery of the hole in a perpendicular direction to the load axis attains a magnitude three times the far field stress under plane stress conditions. However, in a composite panel, the location and magnitude of the maximum stress are at the periphery of the hole changes with the fibre orientation and stacking sequence, therefore designers opt for large safety margins. This study has been performed to investigate the pre-damaged SCF and progressive-damaged SCF for anisotropic/orthotropic material analogous to elastic and plastic deformations in isotropic material respectively. The study presents a novel technique of calculating progressive-damaged SCF which evaluates the changing SCF in response to the progressive damage development within the composite panel. Finite Element (FE) representations simulate delamination damage using cohesive elements and in-plane damage using continuum damage mechanics. In the first part of the study, test coupons have been formulated under static conditions to consider important influencing factors on the SCF for the case of the composite panel containing a central circular hole subjected to tensile loading and compared with the already published literature. Later, several xii FE coupons have been formulated to precisely investigate the pre-damaged SCF and progressivedamaged SCF for the composite panel. During the study, the investigations of pre-damaged SCF and progressive-damaged SCF have also been performed using analytical and experimental approaches where applicable. The FE results are found in good agreement with the analytical and experimental results. The study provides a novel systematic FE approach for the estimation of progressive-damaged SCF for a composite panel, which has not been reported in the literature before. Certainly, the study proposes a paradigm shift in design philosophy which at present is limited to no-damage philosophy especially in aerospace, where the weight savings due to less generous safety factors are significant.