89 research outputs found

    Synthesis and characterization of cobalt based ferrite

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    Magnetoelectric (ME) materials have the ability to convert magnetic energy into electrical energy and/or vice versa. This work involves the study of structural, electrical and magnetic properties of (f)Ni(1-x)(Co/Mn)xFe2O4/Pb(Mg0.33Nb0.67)0.67 Ti0.33O3 nanocomposites, which have been successfully synthesized by chemical co-precipitation method. The presence of both phases in the composites were confirmed by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibration sample magnetometer (VSM). The variations of dielectric constant and loss tangent as a function of frequency as well as temperature were studied using two-point probe impedance analyzer. Temperature dependent dielectric constant shows diffused phase transition in magnetoelectric nanocomposites. The DC electrical resistivity measurements were carried out within the temperature range of 300 – 923 K. Variation of magnetoelectric voltage coefficient traces the path of magnetostriction as a function of magnetic field. All composites show peak behavior in magnetic field dependent on magnetoelectric voltage coefficient. The magnetoelectric (ME) powder nanocomposite system of (f) Ni(1-x)(Co/Mn)xFe2O4+ (1-f) Pb(Mg0.33Nb0.67)0.67Ti0.33O3 (with x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) and f = 0.15, has been successfully studied. The magnetoelectric coefficient for all the composites were measured using static magnetoelectric set up. All magnetic field dependent of magnetoelectric measurements show peak behaviour, which can be explained on the basis of magnetic field dependent variation of magnetostriction and piezomagnetic coefficient behavior. The strong compositional dependent of magnetoelectric voltage coefficient is a common feature for ferrite base nanocomposites. In this study the magnitude of the magnetoelectric coefficient is found to be higher with increasing amount of ferrite phase in nanocomposites samples. The magnetoelectric studies show that high resistive magnetic phase with high piezomagnetic coefficient in low magnetic field region is helpful to enhance the magnetoelectric coupling. The present data suggest that the magnetoelectric interaction depends on the magnetostriction behaviour, piezomagnetic coefficient, resistivity, content of constituent phases and connectivity between the phases

    Improve the Process of Enhancing Oil Recovery (EOR) by Applying Nanomagnetic Cobalt Ferrite Nanoparticles

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    In this paper we reported nano-crystalline cobalt ferrite powders were synthesized using co-precipitation method at 600 °C, 700 °C and 800 °C. The structural, morphological and magnetic properties of the powders were investigated by x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Infrared spectral analysis data between 200 and 1000 cm-1 defined the intrinsic cation vibrations of the characteristic spinel structure system. The saturation magnetization (Ms) and coercivity (Hc) of the CoFe2O4 were found to be in the range of 94-33 emu/g, which is still in the range of hard ferrite. The observed variation in saturation magnetization, coercivity and remanence magnetization as a function of increasing the temperature and grain size of samples. From this point of view, nano-scale size of nanoparticles makes them efficient for using in borehole stability maintaining for enhancing oil and gas recovery efficiency improvement. The large value of magnetic pressure (-2.95699) are expected to be useful in oil recovery applications. It has also been found that the choice of nanoparticles for application in oil recovery depends on nature, magnetic and electric properties of the reservoir rock

    Cu2+ and Al3+ co-substituted cobalt ferrite: structural analysis, morphology and magnetic properties

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    Cu-Al substituted Co ferrite nanopowders, Co1-xCux Fe2-x Alx O4 (0.0 ≤ x ≤ 0.8) were synthesized by the co-precipitation method. The effect of Cu-Al substitution on the structural and magnetic properties have been investigated. X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) are used for studying the effect of variation in the Cu-Al substitution and its impact on particle size, magnetic properties such as Ms and Hc. Cu-Al substitution occurs and produce a secondary phase, α-Fe2O3. The crystallite size of the powder calcined at 800°C was in the range of 19-26 nm. The lattice parameter decreases with increasing Cu-Al content. The nanostructural features were examined by FESEM images. Infrared absorption (IR) spectra shows two vibrational bands; at around 600 (v1) and 400 cm-1 (v2). They are attributed to the tetrahedral and octahedral group complexes of the spinel lattice, respectively. It was found that the physical and magnetic properties have changed with Cu-Al contents. The saturation magnetization decreases with the increase in Cu-Al substitution. The reduction of coercive force, saturation magnetization and magnetic moments are may be due to dilution of the magnetic interaction

    EVALUATION OF SOME CHENOPODIUM QUINOA CULTIVARS UNDER SALINE SOIL CONDITIONS IN EGYPT

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    This study aimed to evaluate seed yield, morphological variability and nutritional quality for two cultivars of Chenopodium quinoa under high saline soil conditions (ECe 22 dSm-1) in Egyptian Northeastern coast. Responses to salinity were greatly differed between the two cultivars. The Peruvian cultivar CICA produced seed yield significantly higher than Bolivian cultivar Real. CICA cultivar also showed significant high performances for most of morphological traits. Among the 10 morphological traits, leaves dry weight, shoot fresh weight and leaves fresh weight showed significant positive association with seed yield. No significant difference has been found between both cultivars for most seed quality traits except for the concentration of crude protein and crude fiber in seeds were significantly higher in CICA cultivar. Although CICA cultivar exhibited significantly higher sodium concentration in the leaves than that found in the leaves of Real cultivar, but it was much more efficient in restricting sodium uploading into seed. These results revealed that the Peruvian cultivar CICA seems to be adaptable and more suited to dry-saline soil in Northeastern coastal region of Egypt, as it gave considerable high seed yield with better quality in terms of high protein and fiber percentage and low Na concentration in seeds

    Quinoa in Egypt - plant density effects on seed yield and nutritional quality in marginal regions

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    Grain quinoa is a halophyte crop with potentially increasing cultivation area. Yet, no standards exist for optimum plant density in arid-regions. The aim of this work was to evaluate the effect of planting density on Peruvian valley type of Chenopodium quinoa Willd. cv. CICA from the standpoint of yield and seed quality in marginal area. Two Field experiments were conducted over two consecutive seasons viz., 2015-2016 in a marginal land at El-Fayoum oasis, Egypt with one quinoa cultivar and two planting densities namely, 56.000 plant ha-1(Low) and 167.000 plant ha(High). A complete randomized block design with six replicates was used. Seed yield increased by 34.7% with increase of plant density from 56.000 plant ha-1 to 167.000 plant ha-1. The increase of plant density significantly decreased weight of 1000-seeds and weight of hectoliter. Protein and ash concentrations in seeds increased at low planting density, whereas carbohydrate concentration decreased. However, there were no significant differences between the two planting densities on the seed concentration of the crude fiber or total fat. Regarding effects of plant density on mineral content in quinoa seeds, the calcium and magnesium contents significantly increased at low density compared with high planting density. Meanwhile, no significant effects of plant density on phosphorus, potassium, iron and zinc content in quinoa seeds were detected. Thus, the present study concludes that the plant density that gives higher seed yield is associated with significant reduction in seed quality in terms of protein content. On the other hand, low plant density significantly increased weight of 1000-seeds and hectoliter, which is reflected on the grain size. The latter is considered as a very important parameter for quinoa global market preference.Fil: Eisa, Sayed S.. Faculty Of Agriculture, Ain Shams University, Cairo; EgiptoFil: Abd El Samad, Emad H.. National Research Centre, Egypt; EgiptoFil: Hussin, Sayed A.. Faculty Of Agriculture, Ain Shams University, Cairo; EgiptoFil: Ali, Essam A.. Desert Research Center, Egypt; EgiptoFil: Ebrahim, Mohamed. Faculty Of Agriculture, Ain Shams University, Cairo; EgiptoFil: González, Juan Antonio. Fundación Miguel Lillo; ArgentinaFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Erazzú, Luis Ernesto. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: El Bordeny, Nasr E.. Faculty Of Agriculture, Ain Shams University, Cairo; EgiptoFil: Abdel-Ati, Ahmed A.. Desert Research Center, Egypt; Egipt

    Germanate oxide impacts on the optical and gamma radiation shielding properties of TeO2-ZnO-Li2O glass system

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    In this work, a series of tellurite glass combined with various concentrations of germanium oxide was fabricated according to the formula of (70-x)TeO2-xGeO2–20ZnO-10Li2O where x = 5, 10, 15 and 20 mol% via utilizing the melt-quench method for possible use in a radiation shielding applications. X-ray diffraction and Attenuated Total Reflectance Fourier Transform Infrared was employed to investigate the structure of the synthesized glasses. The density and Poisson's ratio for current samples reduced gradually from 5.221–5.008 g.cm−3 and 0.134–0.131, respectively, while the enhancement in bandgap values from 3.700–3.872 eV with addition of GeO2 is observed. The linear attenuation coefficient values at 0.015 MeV are 230.123 and 236.832 cm−1 for samples TG1 and TG4, respectively. Moreover, the lowest half-value layer attained via TG1 and raises from 0.0030 to 3.6684 cm while the highest HVL attained by TG4 and raises from 0.0029 to 3.9696 cm

    Incident type 2 diabetes attributable to suboptimal diet in 184 countries

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    The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.814.4 million) incident T2D cases, representing 70.3% (68.871.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.027.1%)), excess refined rice and wheat intake (24.6% (22.327.2%)) and excess processed meat intake (20.3% (18.323.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.487.7%)) and Latin America and the Caribbean (81.8% (80.183.4%)); and lowest proportional burdens were in South Asia (55.4% (52.160.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally. (c) 2023, The Author(s)

    Children's and adolescents' rising animal-source food intakes in 1990-2018 were impacted by age, region, parental education and urbanicity

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    Animal-source foods (ASF) provide nutrition for children and adolescents physical and cognitive development. Here, we use data from the Global Dietary Database and Bayesian hierarchical models to quantify global, regional and national ASF intakes between 1990 and 2018 by age group across 185 countries, representing 93% of the worlds child population. Mean ASF intake was 1.9 servings per day, representing 16% of children consuming at least three daily servings. Intake was similar between boys and girls, but higher among urban children with educated parents. Consumption varied by age from 0.6 at <1 year to 2.5 servings per day at 1519 years. Between 1990 and 2018, mean ASF intake increased by 0.5 servings per week, with increases in all regions except sub-Saharan Africa. In 2018, total ASF consumption was highest in Russia, Brazil, Mexico and Turkey, and lowest in Uganda, India, Kenya and Bangladesh. These findings can inform policy to address malnutrition through targeted ASF consumption programmes. (c) 2023, The Author(s)

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world
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