Ni–W–P electrodeposits were synthesized in a Hull cell in order to simulate the obtainment under industrial conditions. Complete coverage of panels was accomplished by applying total currents of 1.0 and 2.0 A. Panels obtained with a current of 1.0 A appeared brighter. The best compositional uniformities, as determined by Energy Dispersive Spectrometer (EDS) occurred in the current density ranges of 0.6 to 3.0 A dm−2 and 1.6 to 6.0 A dm−2 obtained with 1.0 and 2.0 A, respectively. However, the best morphological characteristics, as determined by Scanning Electro Microscope (SEM), were observed in those obtained with a total current of 1.0 A. Analysis of corrosion resistance by Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Linear Polarization (PLP) in NaCl have shown significant variations in the amount of corrosion potential, polarization resistance, and even total impedance. The alloys exhibited amorphous character (XRD) and crystallized above 400 °C to Ni and Ni3P phases, and possibly Ni–W, with a subsequent increase in hardness. The results suggest that under industrial conditions, current density variations due to the large and complex geometric shapes of substrates lead to formation of distinct alloys. Furthermore, these materials are potential substitutes for chromium deposits in many applications.

O objetivo deste trabalho foi investigar as características físico-químicas e o comportamento reológico de alguns méis florais de espécies de plantas silvestres encontradas no bioma caatinga, assim como, correlacionar as viscosidades dos méis com sua composição química. Neste sentido, cinco méis com predominância floral de plantas típicas da caatinga visitadas por abelhas melíferas foram analisadas. Os resultados mostraram que o teor de umidade dos méis variou entre 17,45 e 21,50 g/100g. As amostras exibiram maiores teores de frutose (37,58 - 43.95 g/100g) e menores teores de glicose (27.41 - 33.80 g/100g). A razão glicose/água variou entre 1,55 e 1,80. Os teores de sacarose, com exeção das amostras de mel de Croton campestris, exibiram valores acima do mais alto teor permitido pela legislação brasileira (6,0 g/100g). Os teores de cinza variaram entre 0,02 e 0,19%. Os teores de sólidos insolúveis ficaram acima de 0,1 g/100g. A condutividade elétrica variou entre 144,90 e 412,55 µS.cm–1. Todas as amostras de mel comportaram-se como fluidos Newtonianos. Os valores das viscosidades, medidos a 293 K, ficaram entre 1,90 e 8,55 Pa.s. Um modelo matemático empírico, adaptado do modelo de Arrhenius, fornece uma boa descrição da viscosidade dos méis como função dos efeitos combinados da temperatura e do teor de umidade.

The aim of this paper was to investigate the physicochemical characteristics and rheological behavior of some floral honeys from species of wild plants found in the Caatinga biome, as well as, correlate honey viscosities with its chemical composition. Thus, five honeys with floral predominance of typical plants foraged by honeybees in Caatinga were analyzed. Results showed that moisture content of honeys ranged from 17.45 to 21.50 g/100g. The samples exhibited higher fructose content (37.58 - 43.95 g/100g) and lower glucose content (27.41- 33.80 g/100g). The glucose-water ratio ranged from 1.55 to 1.80. Sucrose contents, excluding Croton campestris honey sample, exhibited values above the highest sucrose content (6.0 g/100g) allowed by Brazilian norm. The ash content ranged from 0.02 to 0.19 %. The insoluble solids content were above 0.1 g/100 g. The electrical conductivity ranged between 144.90 and 412.55 µS.cm–1. All the honey samples behaved as Newtonian fluids. The viscosity values, measured at 293 K, varied from 1.90 to 8.55 Pa.s. An empirical mathematical model adapted from the Arrhenius model provides a good description of honey viscosity as a function of combined effects of temperature and moisture content.