Electrodeposition of Ni-P/SiC Composite Films with High Hardness

This chapter describes the effect of SiC particle concentrations on the metallic continuous phase of the coating and the effect of heat treatment on the crystalline structure, hardness, and wear resistance of electrodeposited Ni-P-SiC coatings. The deposits were obtained via electrodeposition onto an AISI 1018 steel electrode and then heat treated at various temperatures ranging from 300 °C to 600 °C for 60 min in air. The tribological characteristics studied included hardness, friction coefficient, and wear resistance. The results indicated that the dispersion of SiC particles in the metallic matrix improves coating tribological properties such as hardness and wear resistance while diminishing the friction coefficient. The Ni-P-SiC alloy was originally amorphous and was transformed into a mixture of amorphous and crystalline phases when was thermally treated in the range from 400 °C to 500 °C. This phase transformation was associated with the precipitation of a mixture of Ni3P intermetallic compound and pure Ni crystals. In addition, the results showed that the wear resistance of the Ni-P-SiC coating increased with hardness. The maximum hardness (1453.4 HV) was obtained when the Ni-P-SiC coatings were thermally treated at 500 °C

Systematic Physical Exercise and Spirulina maxima Supplementation Improves Body Composition, Cardiorespiratory Fitness, and Blood Lipid Profile: Correlations of a Randomized Double-Blind Controlled Trial

Cardiovascular diseases are part of the highly preventable chronic diseases associated with changes in lifestyle. Within them, physical activity, low-fat and high-fiber diets are distinguished as the main support for prevention, even when supplementation with nutraceuticals has become a very common practice. Fifty-two young sedentary men with excess body weight (body mass index (BMI) ≥ 25 kg·m−2) were enrolled in a randomized-crossover controlled trial [six weeks of a systematic physical exercise with Spirulina maxima or placebo supplementation (4.5 g·day−1)]. Body composition, blood lipid profile, and maximal oxygen uptake were determined pre/post intervention. Pairwise comparisons showed a significant improvement (p < 0.01) on blood lipid profile in the group of exercise plus Spirulina maxima. Moreover, correlations of absolute changes of BMI, body fat percentage, blood lipids and maximal oxygen uptake were statistically significant (p < 0.01). These results indicate that the Spirulina maxima supplementation could be acting in a synergistic way with exercise due to the enhanced effects on body composition, cardiorespiratory fitness, and blood lipid profile. This phenomenon should be considered to reduce risk of cardiovascular disorders

Fenton Discoloration of Ultrasonicated Purple Cactus Pear Juice

The aim of this study was to evaluate the stability of color, betaxanthin, and betacyanin pigments in the presence of Cu(II)-dependent hydroxyl radicals (HO•) from ultrasonicated purple cactus pear juice at amplitudes of 40%, 60%, and 80%, in comparison to untreated sample. L* parameter of juice treated at 40% and 80% amplitude for 25 and 15 min, respectively (11.3 and 9.3, respectively), were significantly higher compared to the control; b* and hue parameters of juice treated at 80%, 25 min showed values of 1.7 and 0.1, respectively. Color differences (ΔE) were lower (&lt;3) for juices treated at high amplitude (80%) and short times (3–5 min). Juice treated at 40% 15 min, 60% 25 min, 80% 15 and 25 min presented high values of betacyanins (281.7 mg·L−1, 255.9 mg·L−1, 294.4 mg·L−1, and 276.7 mg·L−1, respectively). Betaxanthin values were higher in the juices treated at 40% 5 min and 80% 15 and 25 min (154.2 mg·L−1, 135.2 mg·L−1, and 128.5 mg·L−1, respectively). Purple cactus pear juice exhibited significant chelating activity of copper ions and great stability when exposed to HO•