El presente trabajo buscará dar cuenta de las características, identidades políticas y reivindicaciones del estudiantado la Universidad Obrera Nacional (UON) en el periodo fundacional esta casa estudios, que se extiende desde su apertura marzo 1953 hasta sanción ley 14.885/59, normativa mediante oficializa denominación “Universidad Tecnológica Nacional” (UTN) inclusión dentro régimen autarquía ...

abstract soil contamination by heavy metals is yet one of the most important environmental concerns. among heavy metals, nickel and cadmium have dangerous influences on human, animals and plants. the objective of this study was to derive a new model for simultaneous phytoextraction of ni and cd from contaminated soils. consequently, a macroscopic model was derived by combining yield reduction f...

Metal–olivine Fe–Ni exchange distribution coefficients were determined at 1500 8C over the pressure range of 1 to 9 GPa for solid and liquid alloy compositions. The metal alloy composition was varied with respect to the Fe/Ni ratio and the amount of dissolved carbon and sulfur. The Fe/Ni ratio of the metal phase exercises an important control on the abundance of Ni in the olivine. The Ni abunda...

In a 21-d chronic toxicity test in which an F0 generation of Daphnia magna were exposed to waterborne Ni, the no-observable-effect concentration (for survival, reproduction, and growth) was 42 microg Ni L(-1), or 58% of the measured 21-d median lethal concentration (LC50) of 71.9 microg Ni L(-1) (95% confidence interval, 56.5-95.0). Chronic exposure to 85 microg Ni L(-1) caused marked decreases...

The occurrence of nickel (Ni) deficiency of pecan [Carya illinoinensis (Wangenh.) K. Koch] in orchards is an increasingly common problem. There is uncertainly regarding the primary cause of the problem, as orchard soils have plenty of Ni. The influence of essential micronutrients on the endogenous bioavailability of Ni is unknown and is a possible factor triggering Ni deficiency. This study exa...

Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni) and ...

Exposure of the hyperaccumulator Alyssum lesbiacum to nickel (Ni) is known to result in a dose-dependent increase in xylem sap concentrations of Ni and the chelator free histidine (His). Addition of equimolar concentrations of exogenous L-His to an Ni-amended hydroponic rooting medium enhances Ni flux into the xylem in the nonaccumulator Alyssum montanum, and, as reported here, in Brassica junc...

As shown in the preceding chapter, simple binary eutectic Ni-Hf and Ni-Zr braze alloys can be used to successfully join In738 Ni-base superalloy. The joint gap must, however, be narrow (less than 0.15 mm in width) to allow capillary action to draw the filler metal into the joint. Such narrow joint gaps are usually only found in the manufacturing industry. In the repair industry, especially in I...

The formation and morphological evolution of germanides formed in a ternary Ni/Ta-interlayer/Ge system were examined by ex situ and in situ annealing experiments. The Ni germanide film formed in the Ni/Ta-interlayer/Ge system maintained continuity up to 550°C, whereas agglomeration of the Ni germanide occurred in the Ni/Ge system without Ta-interlayer. Through microstructural and chemical analy...

The non-sulfided Ni-PTA/Al2O3 catalyst was developed to produce green diesel from the hydroprocessing of Jatropha oil. The Ni-PTA/Al2O3 catalyst was prepared by one-pot synthesis of Ni/Al2O3 with the co-precipitation method and then impregnanting Ni/Al2O3 with PTA solution. The catalysts were characterized with BET, SEM-EDX, TEM, XRD, XPS, TGA and NH3-TPD. The Ni and W species of the Ni-PTA/Al2...