Sugar-sweetened carbonated beverage consumption correlates with BMI, waist circumference, and poor dietary choices in school children

<p>Abstract</p> <p>Background</p> <p>The prevalence of obesity and overweight is increasing globally. Frequently coexisting with under-nutrition in developing countries, obesity is a major contributor to chronic disease, and will become a serious healthcare burden especially in countries with a larger percentage of youthful population. 35% of the population of Saudi Arabia are under the age of 16, and adult dietary preferences are often established during early childhood years. Our objective was to examine the dietary habits in relation to body-mass-index (BMI) and waist circumference (W_C), together with exercise and sleep patterns in a cohort of male and female Saudi school children, in order to ascertain whether dietary patterns are associated with obesity phenotypes in this population.</p> <p>Methods</p> <p>5033 boys and 4400 girls aged 10 to 19 years old participated in a designed Food Frequency Questionnaire. BMI and W_C measurements were obtained and correlated with dietary intake.</p> <p>Results</p> <p>The overall prevalence of overweight and obesity was 12.2% and 27.0% respectively, with boys having higher obesity rates than girls (P ≤ 0.001). W_C and BMI was positively correlated with sugar-sweetened carbonated beverage (SSCB) intake in boys only. The association between male BMI and SSCB consumption was significant in a multivariate regression model (P < 0.0001). SSCB intake was positively associated with poor dietary choices in both males and females. Fast food meal intake, savory snacks, iced desserts and total sugar consumption correlated with SSCB intake in both boys (r = 0.39, 0.13, 0.10 and 0.52 respectively, P < 0.001) and girls (r = 0.45, 0.23, 0.16 and 0.55 respectively, P < 0.001). Older children reported eating significantly less fruit and vegetables than younger children; and less eggs, fish and cereals. Conversely, consumption of SSCB and sugar-sweetened hot beverages were higher in older versus younger children (P < 0.001). BMI and W_C were negatively correlated with hours of night-time sleep and exercise in boys, but only with night time sleep in girls, who also showed the lowest frequency of exercise.</p> <p>Conclusions</p> <p>A higher intake of SSCB is associated with poor dietary choices. Male SSCB intake correlates with a higher W_C and BMI. Limiting exposure to SSCB could therefore have a large public health impact.</p

Polyurethane foam-based radar absorbing sandwich structures to evade detection

Polyurethane foam-based sandwich structures were developed for radar absorbing properties together with load bearing capability. The sandwich construction of radar absorbing structure comprised glass fiber epoxy matrix composite containing carbon black as front face skin, carbon fiber epoxy matrix composite as back face skin, and polyurethane foam reinforced with carbonyl iron or graphite powder as the core material. The quantity of carbon black in the front face skin composite was varied from 6 wt.% to 8 wt.%, while the loading of carbonyl iron and graphite powder in foam core was varied from 30 wt.% to 55 wt.% and 5 wt.% to 30 wt.%, respectively. The compression molding technique was used to prepare face skins and sandwich structures. Different combinations of the sandwich structures were characterized for a frequency range of 2–18 GHz using free space measurement method. The maximum attenuation of −31.85 dB was observed in a combination containing 6 wt.% carbon black in front face skin and 20 wt.% graphite powder in the foam core. The total reduction in radar cross-section demonstrated almost zero radar signature at nine different frequencies, whereas broad range attenuation of −10 dB was achieved. </jats:p

A comparative study on the performance of cementitious composites resilient to airfield conditions

With increasing advancement in military aircraft technology, concrete pavements at Australian airbases have been experiencing premature degradation as manifested by scaling. It occurs progressively on the surface of concrete and causes higher maintenance cost and disruption to aircraft operation. This study elucidates the underlying mechanisms of scaling and recommends some low-cost alternative cementitious composites resilient to the airbase operating conditions. To prepare those cement composites, Portland cement (PC) was treated with epoxy resin, acrylic emulsion (AE) and silica fume (SF). Moreover, fly ash (FA) based geopolymer was fabricated and used as another candidate. The resilience of geopolymer, epoxy-SF-cement, AE-SF-cement, and plain PC mortar (control) are examined after prolonged exposure to reproduced airfield environmental conditions. The exposures conditions are applied cyclically until surface scaling is formed. XRD (X-ray diffraction) and FTIR (Fourier transform infrared spectroscopy) analysis are performed to detect the decomposition of crystal lattices of mineral compounds and the degradation of covalent bonds in the cement composites. Also, changes in microstructures, loss of mass and percentages of decreases in the strength of the cement composites are determined. Scaling is developed on the plain PC mortars at the end of 2 months of exposure. However, no scaling is observed on the geopolymer, epoxy-SF-cement, and AE-SF-cement mortars even after 5 months of exposure. In comparison with all cement composites used in this study, the epoxy-SF-cement mortar retained the highest percentage of the strength and exhibited substantially better resistance to the exposure conditions used. Thus, this study recommends the epoxy-SF-cement composite to repair and rehabilitate scale concrete at military airbases. Besides, geopolymer can be used for regular construction at army airbases to combat the saponification problem noticed at an early age of exposures