Solar Carboreduction of Alumina under Vacuum

AbstractMain requirements for successful production of aluminum via carboreduction of alumina using solar vacuum reactors are sufficiently high reaction temperature, suitable low partial pressure of the product gases, fast heating and quenching at temperature low enough to prevent backward reaction. Based on these requests a batch solar reactor was modeled, designed, built and tested. Experimental results of the solar tests under different vacuum levels and temperature conditions will be presented. It will be shown that for reaction temperature, which is above the minimal temperature required for full conversion as predicted by thermodynamic calculations for appropriate pressure, the alumina to aluminum conversion is above 90%. Not reaching the full conversion can be explained by the byproducts formation during the initial preheating. At lower reaction temperatures and higher CO partial pressure by products can also be formed when reaching steady state condition both in the forward and backward reactions. This formation in the forward reaction is confirmed by the discovery of larger amounts of Al4C3, Al4CO4 solids as the residual byproducts in the reactants holder and higher alumina content in the deposits on the cold parts of the reactor that originated from the volatile Al2O produced in the forward reaction which during the deposition converts to alumina and aluminum. Decreasing the reaction temperature is accompanied by decreasing the temperature in the hot zone that causes the increasing of the deposit mass there with higher amount of Al4C3 and Al4CO4 produced in the backward reaction. Nano crystalline and amorphous morphology of the deposits in the cold zone caused by fast cooling will also be discussed

Prenatal Polycyclic Aromatic Hydrocarbon (PAH) Exposure and Child Behavior at Age 6–7 Years

Background: Airborne polycyclic aromatic hydrocarbons (PAH) are widespread urban air pollutants from fossil fuel burning and other combustion sources. We previously reported that a broad spectrum of combustion-related DNA adducts in cord blood was associated with attention problems at 6–7 years of age in the Columbia Center for Children’s Environmental Health (CCCEH) longitudinal cohort study

Expression of a rice chitinase gene in transgenic banana ('Gros Michel', AAA genome group) confers resistance to black leaf streak disease

Peer reviewe

Biochar successfully replaces activated charcoal for in vitro culture of two white poplar clones reducing ethylene concentration

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Interaction of Copper-Based Nanoparticles to Soil, Terrestrial, and Aquatic Systems: Critical Review of the State of the Science and Future Perspectives

In the past two decades, increased production and usage of metallic nanoparticles (NPs) has inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on the usage of NPs in everyday life and has become a matter of public health concern. Among the metallic NPs, Cu-based NPs have gained popularity due to their cost-effectiveness and multifarious promising uses. Several studies in the past represented the phytotoxicity of Cu-based NPs on plants. However, comprehensive knowledge is still lacking. Additionally, the impact of Cu-based NPs on soil organisms such as agriculturally important microbes, fungi, mycorrhiza, nematode, and earthworms are poorly studied. This review article critically analyses the literature data to achieve a more comprehensive knowledge on the toxicological profile of Cu-based NPs and increase our understanding of the effects of Cu-based NPs on aquatic and terrestrial plants as well as on soil microbial communities. The underlying mechanism of biotransformation of Cu-based NPs and the process of their penetration into plants has also been discussed herein. Overall, this review could provide valuable information to design rules and regulations for the safe disposal of Cu-based NPs into a sustainable environment

Molecular Control of Flower Development

The last decade has been an exciting period in plant molecular biology in general and in molecular studies of flower development in particular. The isolation of the first floral meristem identity and floral homeotic genes of Arabidopsis in the late 1980s—early ‘80s opened the way to in-depth studies of molecular aspects of floral development (Bowman et al., 1989; Coen et al., 1990; Sommer et al., 1990; Yanofsky et al., 1990). These investigations have led to insights into inflorescence and flower development in higher eudicotyledonous flowering plants, using mainly the predominant model of Arabidopsis thaliana (thale cress). The abundance of mutants, a relatively small genome, and easy transformation procedures have made this small plant a primary tool of modern plant biology. Among the ornamentals, Antirrhinum majus (snapdragon) and Petunia hybrida (petunia) are the best-characterized plants at the molecular level. As far as is known, flower development in these species follows genetic principles and mechanisms similar to those in Arabidopsis, although some differences exist in the details at the molecular level, and will be discussed later