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The presence of niobium in the alloy creates regions of intermetallic phases contained in Al54Nb45B7 amorphous alloy which becomes a potent heterogeneous nucleation on the substrate for nucleation with dendritic presence of aluminum oxides due to diffusive processes on the surface of the amorphous alloy Al54Nb45B7. This alloy is extremely low cost, but with applications in many sectors of the chemical and petrochemical industry in emphasis because its mechanical deformation is high due to the presence of (Nb or B) in the aluminum acting mainly as grain refiners to improve their mechanical and thermal properties by using the mechanical alloying. The combined use of Niobium and Boron (intermetallic phases are formed by adding powder of Al and Nb), instead of Niobium or Boron, individually, is a highly effective way to refine the grain size of alloy Al Nb-B in their microstructure without causing inconvenience in your network for unwanted deformations. To that end the present study compared the effect of grain refining promoted by the addition of niobium and the addition of Boron in Al54Nb45B5 obtained by high energy mill under argon atmosphere and analyzed by diffraction of X rays (XRD), scanning electron microscopy and Energy Dispersive (SEM / EDS). [ABSTRACT FROM AUTHOR]

The presence of niobium in the alloy creates regions of intermetallic phases contained in Al54Nb45B7 amorphous alloy which becomes a potent heterogeneous nucleation on the substrate for nucleation with dendritic presence of aluminum oxides due to diffusive processes on the surface of the amorphous alloy Al54Nb45B7. This alloy is extremely low cost, but with applications in many sectors of the chemical and petrochemical industry in emphasis because its mechanical deformation is high due to the presence of (Nb or B) in the aluminum acting mainly as grain refiners to improve their mechanical and thermal properties by using the mechanical alloying. The combined use of Niobium and Boron (intermetallic phases are formed by adding powder of Al and Nb), instead of Niobium or Boron, individually, is a highly effective way to refine the grain size of alloy Al Nb-B in their microstructure without causing inconvenience in your network for unwanted deformations. To that end the present study compared the effect of grain refining promoted by the addition of niobium and the addition of Boron in Al54Nb45B5 obtained by high energy mill under argon atmosphere and analyzed by diffraction of X rays (XRD), scanning electron microscopy and Energy Dispersive (SEM / EDS). [ABSTRACT FROM AUTHOR]

This study aims to investigate and characterize the amorphous alloy Co72Nb24B4 the catalytic oxidation of methanol in products that serve as primary reagents for organic synthesis, such as formaldehyde and other intermediate products. The technique for obtaining the amorphous alloy was electric arc smelting furnace. The amorphous alloy catalyst Co72Nb24B4 was characterized by XRD, SEM / EDS, BET and thermal analysis TGA and DTA. The objective of this work is to develop and study the application of amorphous alloy as catalysts and catalyst supports, due to its thick this oxide layer on its surface capable of oxidizing methanol and intermediates of methanol oxidation reaction. The amorphous alloy structure Co72Nb24B4 is still stable after the catalytic test, since the formation of intermetallic and amorphous phases are rich in active sites that are important for the catalytic processes at the surface of these amorphous materials. [ABSTRACT FROM AUTHOR]

Objective: To evaluate and systematize tongue color-related manifestations among patients with PCR-confirmed COVID-19 infection. Material and Methods: This retrospective study included analysis of tongue images obtained from patients with PCR-confirmed COVID-19 infection. Evaluation of coronavirus disease severity (mild, moderate, severe, critical) was provided, considering clinical symptomatology and results of laboratorial and instrumental diagnostic methods. Each picture was analyzed considering the parameters of color of the tongue and color of the tongue plaque by two dental specialists. Cochran-Armitage test for trend was used to evaluate associations between the tongue color and tongue plaque color, and coronavirus disease severity. Results: The most prevalent tongue colors were pale pink, red and dark red (burgundy color). A total of 64.29% of patients with mild disease demonstrated pale pink color of the tongue. Patients with moderate coronavirus disease were characterized with the adverse trend: 62.35% of them presented with red-colored tongue, while in 37.64% of cases, the tongue was pale pink. Severe COVID-19 patients, almost in 90% of the cases, had either red or burgundy color of the tongue. Conclusion: SARS-COV-2 infection is not manifested by tongue-targeted or tongue-specific signs and features; however, coronavirus disease itself provokes changes within the tongue color and tongue plaque color similar to those registered during other internal pathologies.

The present work aimed to characterize the microstructure of the icosahedral phase (quasicrystalline phase-f)of the system with stoichiometric composition of the quasicrystal Al67Cu26Fe15. The ternary alloy with nominal composition of Al67Cu26Fe15 was processed by High Power Mechanical Milling as a viable solid state processing method for producing various metastable and stable quasicrystalline phases. The structural characterization of the obtained samples was performed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the elemental composition was determined by dispersive energy spectroscopy (DES). On the surface of the quasicrystalline alloy, we can observe in the SEM the presence of -Al2O3 alumina, which contributes to the textural properties of the catalytic support, revealing its catalytic activity,aiming at a higher performance in methanol oxidation reactions. The diffraction patterns of Al67Cu26Fe15 showed the presence of w-Al7Cu2Fe, b-Al(Fe;Cu) and l-Al13Fe4 phases that coexist with the thermodynamic quasicrystalline phase-?. Finally, elemental analysis indicates that during alloy synthesis there is little variation of the ideal composition. The results indicate that alloys with high percentage of icosahedral phase can be obtained by casting in the air.