Composition Of Constituent Materials Research Articles

Nanotoxicity of Emerging NMC-Family Energy Storage Nanomaterials

The increasing use of metal oxide materials has met with equal concern as regards associated health risks and environmental transference. NMC-family (LiNi_xCo_yMn_zO₂, where x+y+z=1) energy storage materials are complex transition metal oxides that are being rapidly deployed as replacements to the conventional lithium-ion batteries (LiBs) in the electric vehicle industry. Sustainable catalysis is another area of increasing study since multi-component oxides have a high propensity for cleaving strong chemicals such as the carbon-fluorine bond. NMC materials are mostly synthesized through different thermomechanical processes, with the final composition depending on the required properties in the derived nanostructures. The biological impact of NMC-type materials has been found to be dependent not just on the overall mass, but also on the mass distribution which could be in the form of micro or nanostructures. This study therefore assesses the toxicity effect of NMC-family nanoscale material for energy storage and catalysis, with a view to determining possible safety levels as regards the composition of constituent materials. Preliminary toxicity studies were conducted on inoculated S. oneidensis, B. subtilis and D. magna substrates exposed to NMC materials for time intervals ranging from 0 to 72h and found a direct relationship between the ease of release of Ni and Co ions and cellular respiration and growth. The chemical transformation of NMC nanomaterials was however found to favor an ion release of the order Li > Ni > Co > Mn, although this is an entirely slow process. Altering the configuration of NMC materials through Mn enrichment was also found to significantly reduce its dissolution and could be an important approach to preventing its release into the environment.

Geoarchaeological evidence for ritual closure of a kiva at Fourmile Ruin, Arizona

Geoarchaeological analyses, including soil micromorphology and chemistry, were used to characterize the deposition history of a fourteenth-century Pueblo ceremonial structure (or kiva) at Fourmile Ruin, east-central Arizona. These subterranean structures were often ritually “closed” by Pueblo societies through the burning of roofs and the deposition of special objects. These conspicuous markers are absent in the Fourmile Ruin kiva, but the composition of constituent materials and sedimentation processes nonetheless signal complex, highly-orchestrated closure activities. The study demonstrates the efficacy of geoarchaeological analyses of stratified deposits for modeling the subtle behaviors associated with the ritual closure and abandonment of sacred places.

Efficient representation of bidirectional reflectance distribution functions for metallic paints considering manufacturing parameters

Metallic paint has been widely used to provide for special visual appearance to various products so that photorealistic rendering of this material has been an important issue in the development of new products. We introduce a new approach that predicts the reflectance of metallic paint while considering manufacturing parameters. Our main idea is to simulate the appearance of various metallic paints having different composition of constituent materials by combination of measured bidirectional reflectance distribution functions and thereby to find a paint that provides optimal appearance of a product with appropriate composition of constituent materials. We mainly focused on two paint parameters, average size and density of aluminum flakes, because they significantly affect the appearance of metallic paint. We also present a compact representation to approximate a large size of measured data using a few curve functions. We demonstrate the efficiency and usability of our reflectance estimation method using some examples.