Graphene phytotoxicity in the seedling stage of cabbage, tomato, red spinach, and lettuce

The effects of graphene on root and shoot growth, biomass, shape, cell death, and reactive oxygen species (ROS) of cabbage, tomato, red spinach, and lettuce, were investigated using a concentration range from 500 to 2000 mg/L. The results of the combined morphological and physiological analyses indicate that after 20 days of exposure under our experimental conditions, graphene significantly inhibited plant growth and biomass compared to a control. The number and size of leaves of the graphene-treated plants were reduced in a dose-dependent manner. Significant effects also were detected showing a concentration-dependent increase in ROS and cell death as well as visible symptoms of necrotic lesions, indicating graphene-induced adverse effects on cabbage, tomato, and red spinach mediated by oxidative stress necrosis. Little or no significant toxic effect was observed with lettuce seedlings under the same conditions. The potential effect of graphene largely depends on dose, exposure time, and plant species and deserves further attention.     

The carbon footprint and energy consumption of a commercially produced earthenware ceramic piece

The product carbon footprint quantifies the greenhouse gas (GHG) emissions during the life cycle of a product, from the extraction of raw materials, through the production, use and recycling, to the disposal of the used product.In this study, the carbon footprint of an ornamental earthenware ceramic piece has been estimated following the PAS 2050:2011 methodology, and the energy and GHG hotspots have been identified.The carbon footprint and the total energy consumption of the selected ceramic piece is 1.22 kg CO₂e per piece and 8.19 kWh, respectively.The manufacture represents almost 90% of the carbon footprint of the piece.The energy hotspots are natural gas production, biscuit firing and condensing boiler. Some measures to reduce the consumption of natural gas and electricity have been applied, such as the implementation of a gas pressure control system in the kilns and the mill lighting system optimization, respectively.     

Liquid phase sintering of ferrite of NiCuZn with low magnetic permeability for miniaturization

In this study, we synthesized ferrites with the formula Ni_0.5?xCu_xZn_0.5Fe₂O₄ and sintered them to x = 0, 0.1, 0.2 and 0.3 using the citrate precursor method. We then analyzed the sintered toroids by X-ray diffraction (XRD) with Rietveld refinement. Scanning electron microscopy (SEM) results showed there to be uniform grains in NiZn, abnormal grains at x = 0.2 with a remnant of the CuO liquid phase, and large grains at x = 0.3. We then analyzed the toroids by vibrating sample magnetometry (VSM). The hysteresis reached a saturation magnetization (Ms) value of 88.37 emu/g and a coercive field (Hc) of 0.0016 T. We calculated the Bohr magnetons using the Ms information and obtained the magnetic permeability with a vector network analyzer (VNA). The toroid with the remnant CuO phase showed relative permeability values of between 20 and 30 and low losses in a wide range of frequencies (10–50 MHz), which we attribute to the microstructure characteristics. Based on our results, this ferrite can be used in the miniaturization of magnetic components used in electro–electronic devices.     

Cordierite obtained from compositions containing kaolin waste,talc and magnesium oxide

The purpose of this study was to obtain cordierite from compositions containing kaolin waste (with different particle-size distributions), talc and magnesium oxide, for use in the production of refractory and insulating materials. The samples were characterized by means of the following techniques: chemical analysis by X-ray fluorescence, X-ray diffraction, particle size analysis and thermogravimetric and differential thermal analysis. The microstructure of the samples was analyzed using scanning electron microscopy. Rectangular test specimens (50 mm × 15 mm × 5 mm) were prepared by uniaxial pressing (13.0 MPa), dried at 110 °C/24 h and sintered at temperatures of 950, 1050, 1150, 1250 and 1350 °C. The mineralogical analysis revealed the beginning of the formation of characteristic peaks of cordierite phase at 1250 °C, and more intense peaks were identified at 1350 °C. The morphological analysis revealed rose-like and hexagonal tube-like crystals.     

Preparation of CoMoS catalysts for hydrodesulfurization using methylacetoacetate as a chelating agent

CoMoS/Al₂O₃ catalyst, which was prepared using Co(MeAA)₂·2H₂O as a new Co precursor, showed activity for hydrodesulfurization (HDS) higher than that of conventional catalysts, which were prepared using Co(NO₃)·6H₂O as a Co precursor and/or by adding ethylene-di-amine-tetra-acetic acid (EDTA) as a chelating agent. Catalyst of a similar activity was also obtained simply by impregnating a conventional CoMo/Al₂O₃ catalyst with an aqueous solution of methylacetoacetate (MeAA) followed by drying and sulfidation. The added MeAA reacted with Co to produce Co(MeAA)₂·2H₂O on the catalyst surface during impregnation step, such that the resulting catalyst became similar to one prepared by direct impregnation with Co(MeAA)₂·2H₂O. The in-situ synthesis of Co(MeAA)₂·2H₂O on the catalyst surface was advantageous over the method of directly adding the Co precursor to the impregnation solution because the former method did not use a basic material, which was required for the synthesis of the Co precursor. Furthermore, MeAA was soluble in water, whereas Co(MeAA)₂·2H₂O had to be dissolved in an organic solvent, e.g., 1,4-dioxane. The Co species in the MeAA-added catalysts were sulfided at temperatures higher than those of conventional catalysts, and consequently the former catalysts contained greater amounts of the HDS-active CoMoS phase than the latter.     

Thoracic epidural angiolipoma. Report of a case

Angiolipomas of the spine are rare (40 cases in the literature). When they are intraspinal, these masses are epidural in more than 90% of the cases. Angiolipomas are benign tumors containing vascular and mature adipose elements. The clinical symptomatology is non specific, but computed tomography and mostly MRI provide a precise diagnosis. With one additional case and a review of the literature, we define the main characteristics of these tumors.