Microstructure, Critical Behavior and Magnetocaloric Properties of Melt-Spun Ni51.82Mn32.37In15.81

Heusler alloy with an atomic composition of Ni51.82Mn32.37In15.81 was prepared by melt spinning from arc-melted ingots. X-ray diffraction, scanning electron microscopy and magnetic measurements were used to study the structural, microstructural and magnetic properties. The crystal structure consists of a mixture of B2 austenite (~50%) and 14M martensite (~50%). The alloy undergoes a second order magnetic transition at a Curie temperature of TcA=194.2 K. The hysteresis loop reveals the occurrence of exchange bias phenomenon at room temperature. The critical exponents β, γ and δ were estimated using modified Arrott plots, Kouvel–Fisher curves and critical isothermal analysis. The respective values are β=0.500±0.015, γ=1.282±0.055 and δ=3.003±0.002. The critical behaviour in ribbons is governed by the mean field model with a dominated long-range order of ferromagnetic interactions. The maximum entropy change, ∆SMmax, for an applied magnetic field of 5 T reaches an absolute value of 0.92 J/kg·K. The experimental results of entropy changes are in good agreement with those calculated using Landau theory

Vitamin A intake in school-aged children in Draa-Tafilalet oasis regions, southeastern of Morocco

Vitamin A has several important functions such as preventing childhood blindness and strengthening the immune system against common diseases in children. The purpose of the present work was to assess the nutritional intake of vitamin A in oasis school-age children. A cross-sectional survey was carried out among children enrolled in public primary education establishments. 4244 school-aged children were randomly selected to take part in the study. Data on dietary vitamin A intake was assessed by the 24-hour dietary recall. Socio-economic characteristics were got using an appropriate questionnaire. Over the entire sample, the median vitamin A intake was around 409.3 μg for girls and 294.5 μg for boys. The prevalence of insufficient vitamin A intake was observed in 58.3%. The prevalence of inadequate intake according to socio-demographic and economic characteristics shows girls tend to develop vitamin A deficiency compared to boys. Children from urban areas show significant percentages of inadequacy. School-aged children with illiterate parents with low monthly income were identified as at risk of having insufficient dietary intake of vitamin A. In conclusion, we have revealed an important level of inadequacy for vitamin A in the overall processed results that must be considered

Sun exposure, dressing habits, and vitamin D status in Morocco

Sunlight is the main source of vitamin D. Almost 80% of vitamin D3 is produced in the skin. The region of Draa Tafilalet benefits from long daily sunshine time. As such, vitamin D deficiency should be low in this region. However, dressing habits can highly influence vitamin D status. This study aimed to evaluate sun exposure and its relation to vitamin D status among the general population in the region of Draa-Tafilalet, Morocco. Clinical, biological, and sociodemographic data were obtained from 331 adults visiting local healthcare units during the summers of 2019 and 2020. Plasma 25(OH)D2/D3 was measured by immunofluorescence. The prevalence of vitamin D deficiency was 37.5%, while Vitamin D insufficiency represented 56.5%. Most of the studied population (76.4%) had restricting dressing habits and exposed only their faces. statistic tests showed a correlation of vitamin D levels with daily sun exposure (r= 0.308, p<0.001), dressing habits (p<0.001), age (r= -0.141, p=0.01), sex (p<0.001), physical activity level (p=0.003), and BMI (r= -0.298, p<0.001). The study showed a high prevalence of vitamin D deficiency in this region. Similarly, it exposed the effects of restricting clothes and low daily sun exposure on vitamin D status

Microstructure, Critical Behavior and Magnetocaloric Properties of Melt-Spun Ni_51.82Mn_32.37In_15.81

Heusler alloy with an atomic composition of Ni51.82Mn32.37In15.81 was prepared by melt spinning from arc-melted ingots. X-ray diffraction, scanning electron microscopy and magnetic measurements were used to study the structural, microstructural and magnetic properties. The crystal structure consists of a mixture of B2 austenite (~50%) and 14M martensite (~50%). The alloy undergoes a second order magnetic transition at a Curie temperature of TcA=194.2 K. The hysteresis loop reveals the occurrence of exchange bias phenomenon at room temperature. The critical exponents β, γ and δ were estimated using modified Arrott plots, Kouvel–Fisher curves and critical isothermal analysis. The respective values are β=0.500±0.015, γ=1.282±0.055 and δ=3.003±0.002. The critical behaviour in ribbons is governed by the mean field model with a dominated long-range order of ferromagnetic interactions. The maximum entropy change, ∆SMmax, for an applied magnetic field of 5 T reaches an absolute value of 0.92 J/kg·K. The experimental results of entropy changes are in good agreement with those calculated using Landau theory