scholarly journals Zirconia Effect on the Bioactivity and the Mechanical Properties of Calcium Magnesium Silicate Ceramics at (CaO+MgO)/SiO2 Molar Ratio Close to Unity

Author(s):  
Amira MM Amin ◽  
Emad MM Ewais ◽  
Yasser MZ Ahmed ◽  
Eman A Ashor ◽  
Ulrike Hess ◽  
...  
2015 ◽  
Vol 649 ◽  
pp. 1329-1338 ◽  
Author(s):  
Ishwar Prasad Sahu ◽  
Priya Chandrakar ◽  
R.N. Baghel ◽  
D.P. Bisen ◽  
Nameeta Brahme ◽  
...  

2017 ◽  
Vol 900 ◽  
pp. 35-39
Author(s):  
Cheng Chien Wang ◽  
Chih Lung Chiu ◽  
Jian Sheng Shen

The different amount of hydrophilic hydroxyl group, including 3, 5, 7 and 10 wt.% copoly (styrene-co - divinyl benzene – co - 2-hydroxylethylenemethacrylate) (poly (St-co-DVB- co -HEMA) s) nanoparticles were synthesized via microemulsion polymerization in the present paper. The average size of the poly (St-co-DVB-co-HEMA) s was ca. 44 nm after zetasizer (DLS) measurement and SEM observation. The characteristic peaks at 3200 ~3600 cm-1 in FTIR was assigned at hydroxyl group of HEMA unit. The NBR/poly (St-co-DVB-co-HEMA) s composites films with 250 μm thickness were prepared simply via latex mixing and followed by spinning coating. The mechanical properties of the poly (St-co-DVB-co-HEMA) s/rubber nanocomposites, including the tensile strength, modulus and elongation, were increased with that of increasing of poly (St-co-DVB-co-HEMA) s adding. In addition, as the poly (St-co-DVB-co-HEMA) s nanoparticles carried out with constant St/HEMA molar ratio of 97:3 and the DVB content in 10 wt.%, the elongation at break that up to more than 3500% and the ultimate stress increased from 0.2 MPa to 0.6 MPa. The poly (St-co-DVB-co-HEMA) s nanoparticles prepared by emulsion polymerization could be successfully enhanced the mechanical properties of rubber latex.


2021 ◽  
Vol 22 (1) ◽  
pp. 52-59
Author(s):  
O.A. Vrzhesinskaya ◽  
◽  
V.M. Kodentsova ◽  
N.A. Beketova ◽  
O.V. Kosheleva ◽  
...  

The diet of the majority of the population of Russia is characterized by an insufficient content of a number of micronutrients, including macro- and micronutrients. The aim of the study is to characterize in a rat model experiment the effect of combined nutritional deficiency of calcium, magnesium and iodine on the availability of other mineral substances, vitamin metabolism and biochemical parameters blood plasma. The lack of minerals in growing Wistar male rats with an initial body weight (51.4 ± 0.5) g was created for 23 days by halving of a calcium, magnesium and iodine in the salt mixture. Alimentary deficiency of calcium, magnesium and iodine in growing rats significantly and multidirectionally affected the metabolism of other minerals and vitamins, as well as a number of diagnostically significant indicators of blood and urine. In rats of the experimental group, the liver concentration of α-tocopherol, vitamin B1 and retinol palmitate decreased, the concentration of iron and zinc increased, the copper content in the whole brain decreased significantly. The molar ratio of γ- and α-tocopherols in blood plasma was increased, the concentration of the circulating form of vitamin D decreased. The ratio of AlAT / AsAT (de Ritis coefficient) markedly decreased due to increased activity of AlAT. Phosphate reabsorption decreased slightly. Increased urinary excretion of riboflavin was accompanied by a decrease in its concentration in blood plasma. The conclusion that insufficient intake of calcium, magnesium and iodine may disturb vitamin-mineral status of organism has been made.


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4071 ◽  
Author(s):  
Marcos Vinícius Mansano Sarto ◽  
Maria do Carmo Lana ◽  
Leandro Rampim ◽  
Jean Sérgio Rosset ◽  
Jaqueline Rocha Wobeto

<p>An improvement in soil chemical properties and crop development with silicate application has been confirmed in several plant species. The effects of silicate application on soil chemical properties and wheat growth were investigated in the present study. The experiment was carried out in 8-L plastic pots in a greenhouse. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha–1 of calcium/magnesium silicate), with four replications. The plant length, number of spikes per pot, shoot dry matter and grain yield, were measured after 115 days of wheat (<em>Triticum aestivum </em>L.) growth. Changes in the soil chemical properties (pH, H+ + Al3+, Al3+, P, K, Ca, Mg, Si, Cu, Zn, Fe and Mn) were analyzed after wheat harvest. Application of calcium/magnesium silicate reduces the potential acidity (H+ + Al3+) and Al3+ phytotoxic; and increases the soil pH, available Ca, Mg and Si, cation exchange capacity (CEC) and soil base saturation. Silicate application did not affect the available P, exchangeable K and availability of micronutrients (Cu, Zn, Fe and Mn) in the three soils. The application of calcium/magnesium silicate in an acid clayey Rhodic Hapludox improves the development and yield of wheat; however, the silicate application in soil with pH higher to 5.3 and high Si availability does not affect the agronomic characteristics and grain yield of wheat.</p><p><strong> </strong></p>


2019 ◽  
Vol 27 (2) ◽  
pp. 503-513
Author(s):  
Chun Hui Zhou ◽  
Shu Ting Xia ◽  
Sridhar Komarneni ◽  
Freeman Bwalya Kabwe ◽  
Gui Chen Jin ◽  
...  

2019 ◽  
Vol 40 (3) ◽  
pp. 1317
Author(s):  
Jaqueline Rocha Wobeto Sarto ◽  
Marcela Abbado Neres ◽  
Caroline Daiane Nath ◽  
Doglas Bassegio ◽  
Marcos Vinicius Mansano Sarto

Tropical soils are highly weathered, acidic, and low in silicon (Si) availability for plants. Si has been considered an essential nutrient for many grasses. Urochloa Convert HD364 is classified as a forage plant that accumulates Si, but the accumulation of this nutrient in the leaf can influence qualitative characteristics, fiber quality, plant architecture, and development of forage. In this study, we aimed to evaluate the production and nutritive value of Urochloa hybrid cultivar Convert HD364 (CIAT 36087) grown from soils collected in the state of Paraná, Brazil. The experiment was carried out in a greenhouse using 8-L plastic pots and three types of soil. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha-1 of calcium/magnesium silicate), with four replications. Application of CaSiO3 to the soil increases the concentration of Si in the leaves of Urochloa Convert HD364. The dry matter, crude protein and mineral matter, fiber quality, and digestibility of Urochloa were not influenced by the increase in Si levels in the leaves until 45 days after seeding. Forty-five days after planting, CaSiO3 did not interfere with the growth characteristics and production of Urochloa Convert HD364. There is no evidence that the increased Si levels in the leaf affected the production and nutritive value, especially fiber quality of Urochloa Convert HD364 until 45 days after sedding.


Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 50 ◽  
Author(s):  
Weidi He ◽  
Ying Zhou ◽  
Xiaolang Chen ◽  
Jianbing Guo ◽  
Dengfeng Zhou ◽  
...  

In this work, the ethylene-propylene-diene monomer/polypropylene (EPDM/PP) thermoplastic elastomer filled with intumescent flame retardants (IFR) is fabricated by melting blend. The IFR are constituted with melamine phosphate-pentaerythritol (MP/PER) by compounding and reactive extruding, respectively. The effects of two kinds of MP/PER with different contents on the thermal stability, flame retardancy, and mechanical properties of materials are investigated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94, cone calorimeter test (CCT), and scanning electron microscopy (SEM). FTIR results show that the reactive extruded MP/PER partly generates melamine pyrophosphate (MPP) compared with compound masterbatches. TGA data indicate that the best thermal stability is achieved when the molar ratio of MP/PER reaches 1.8. All the reactive samples show a higher flame retardancy than compound ones. The CCT results also exhibit the same trend as above in heat release and smoke production rate. The EPDM/PP composites filled with 30 and 35% reactive MP/PER exhibit the improved flame retardancy but become stiffer and more brittle. SEM photos display that better dispersion and smaller particle size are obtained for reactive samples.


2015 ◽  
Vol 37 (1) ◽  
pp. 85
Author(s):  
Ronald Vargas Orellana ◽  
Neide Pena Coto ◽  
Igor Studart Medeiros ◽  
Reinaldo Brito Dias

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