54 research outputs found
Mobil and total forms of some transitional metal cations in food chain of black currants cultivation and processing
Romania has large natural possibilities through Western Plain, diligence and skill of residents in cultivation and processing of specific and quality horticultural products. In the world there are few areas where the climate, soil and diversity of spontaneous and cultivated flora can provide quality natural food products, with high nutritional value. The experimental results obtained for the heavy metal concentrations in the black currants cultivated on soils close to the C.E.T. Timisoara ash storage reveal higher concentrations for these elements. Higher concentrations for the toxic heavy metals (Cd, Pb) and for the potential toxic heavy metals (Zn, Cu) were identified in some vegetables, especially for leaf vegetables and for the root vegetables. Although some heavy metals were identified in higher concentrations, close to the toxic limits or higher, the mean values for these concentrations in the vegetables were in the range of normal limits. This fact demonstrate that the pollution of this areal is incipient and forward cannot be affirm that the heavy metal pollution process is evident, but this phenomenon could be amplified in the case of a prolonged anthropic impact, and without the specific agro-pedo-ameliorative measures. The classification of the non-polluted and polluted regions is achieved by multivariate analysis (PCA-principal component analysis) of the data using especially the Fe, Mn, Zn, and Cu concentration values for the first and second principal components, and Zn and Fe concentration values for the third principal component
Corrosion Investigations of Materials in Antimony–Tin and Antimony–Bismuth Alloys for Liquid Metal Batteries
Liquid metal batteries are discussed as stationary electrical energy storage for renewable energies, in order to compensate their fluctuating supply of energy. A liquid metal battery consists of three different liquids, which stay segregated due to density differences and mutual immiscibility. The negative electrode is the low-density liquid metal, and in our case sodium, a medium density molten salt, is the electrolyte and positive electrode is a high-density liquid metal. For the latter, Sb–Sn and Sb–Bi alloys are selected. However, one issue is the compatibility of structural materials with the used liquids. In a first step, the behavior of potential structural materials in Sb3Sn7 and SbBi9 at the temperature of 450 °C up to 750 h was tested. The results showed that the corrosion in SbBi9 was significantly less than in Sb3Sn7 and the most promising materials were molybdenum meta and Max-phase coatings
Influence of composition and heating schedules on compatibility of FeCrAl alloys with high-temperature steam
FeCrAl alloys are proposed and being intensively investigated as alternative
accident tolerant fuel (ATF) cladding for nuclear fission application. Herein,
the influence of major alloy elements (Cr and Al), reactive element effect and
heating schedules on the oxidation behavior of FeCrAl alloys in steam up to
1500{\deg}C was examined. In case of transient ramp tests, catastrophic
oxidation, i.e. rapid and complete consumption of the alloy, occurred during
temperature ramp up to above 1200{\deg}C for specific alloys. The maximum
compatible temperature of FeCrAl alloys in steam increases with raising Cr and
Al content, decreasing heating rates during ramp period and doping of yttrium.
Isothermal oxidation resulted in catastrophic oxidation at 1400{\deg}C for all
examined alloys. However, formation of a protective alumina scale at
1500{\deg}C was ascertained despite partial melting. The occurrence of
catastrophic oxidation seems to be controlled by dynamic competitive mechanisms
between mass transfer of Al from the substrate and transport of oxidizing gas
through the scale both toward the metal/oxide scale interface.Comment: Submitted to Journal of nuclear materials, accepted recentl
Evaluation of pulsed electric fields effect on the microalgae cell mechanical stability through high pressure homogenization
Pulsed Electric Fields, a known technique for permeabilization of cell membranes, can considerably foster intracellular component extraction from microalgae. However, it is currently uncertain in what way, apart from the cell membrane, the cell wall is affected during pulsation. In this study, fresh Auxenochlorella protothecoides and Chlorella vulgaris were subjected to treatment with pulsed electric fields and energy input of 1.5 MJ/kgDryWeight. Subsequently the biomass was fed into a High Pressure Homogenizer for 5 passes at 1500 bar. The percentage of intact cells after each pass was determined through cell counting and compared with Control biomass that underwent the same homogenization. No major difference on the disruption degree of pulsed and control samples was observed, indicating that the resistance to mechanical stress of the cell, a function of the cell wall, is not affected by pulsed electric fields. Scanning Electron Microscopy observation also showed no superficial or structural cell alteration after pulsation
Influence of composition and heating schedules on compatibility of FeCrAl alloys with high-temperature steam
Evaluation of pulsed electric fields effect on the microalgae cell mechanical stability through high pressure homogenization
Pulsed Electric Fields, a known technique for permeabilization of cell membranes, can considerably foster intracellular component extraction from microalgae. However, it is currently uncertain in what way, apart from the cell membrane, the cell wall is affected during pulsation. In this study, fresh Auxenochlorella protothecoides and Chlorella vulgaris were subjected to treatment with pulsed electric fields and energy input of 1.5 MJ/kgDryWeight. Subsequently the biomass was fed into a High Pressure Homogenizer for 5 passes at 1500 bar. The percentage of intact cells after each pass was determined through cell counting and compared with Control biomass that underwent the same homogenization. No major difference on the disruption degree of pulsed and control samples was observed, indicating that the resistance to mechanical stress of the cell, a function of the cell wall, is not affected by pulsed electric fields. Scanning Electron Microscopy observation also showed no superficial or structural cell alteration after pulsation
Characterization of Homemade Vanilla Ice Cream
The aim of this work was to achieve a screening on organoleptic and sensory characteristics, physical-chemical properties, microbial load and degree of contamination with heavy metals and arsenic of homemade vanilla ice cream. Dry substance ranged between 31.69% and 32.16%, all samples showing values below the 33% minimum eligibility. Regarding the acidity of the analyzed samples, they were within the legislative norms in force, showing values below 24°T. Also, analyzed  ice cream samples showed no microbial loads or contamination with heavy metals or arsenic
Influence of Si addition on the corrosion behaviour of 9 wt% Cr ferritic/martensitic steels exposed to oxygen-controlled molten Pb-Bi eutectic at 550 and 600 °C
Three 9 wt% Cr ferrite/martensite steels (two alloyed with Si) have been exposed to oxygen-controlled LBE at 550 and 600 °C, respectively. The passivating oxide scale consists of a spinel layer plus internal oxidation zone (IOZ). By adding Si, the thickness of spinel layer is decreased while the IOZ is enhanced. Moreover, a Si-rich oxide layer is observed underneath the spinel layer on Si-containing samples after 2000 h exposure at 600 °C. Besides, the less visible cracks/exfoliations on Si-containing samples indicate the positive role of Si addition on scale adherence
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