Polymer based nanocomposites: synthetic strategies for hybrid materials

Associating the well known advantages of hybrid materials to the wide potential of nanomaterials, the new and featuring class of polymer nanocomposites turned into one of the most intensively researched areas. This review highlights recent developments in the field of the synthesis of polymer based nanocomposites. Important issues related to the surface modification of fillers, in order to promote the compatibility between the inorganic/organic components, are also reported. The enhancement of the physical properties and the potential applications of polymer nanocomposites are considered in typical examples, given for each synthetic method describe

Quantification of root nitrification capacity of bibb lettuce plants for use in a recirculating aquaculture system (RAS)

This research examined the feasibility of Bibb lettuce roots to provide a surface for nitrifying microbes to colonize, removing ammonia from wastewater. The work is geared towards sizing a rotational plant system to act as a natural biofilter to treat wastewater from the fish farming industry, making a recirculating natural system possible. It was observed that these natural, biotic surfaces provide a more suitable area for microbes to grow compared to inert materials. Nitrification rates were quantified, and were similar in magnitude to pre-experiment estimates. In addition, a correlation between Bibb lettuce leaf mass and root surface area was calculated, which greatly simplifies the calculation necessary to size a plant filtration unit

Receipt for bond, 1864

https://egrove.olemiss.edu/aldrichcorr_d/1017/thumbnail.jp

Media Coverage of Climate Change: Current Trends, Strengths, Weaknesses

human development, climate change

Cognitive Flexibility Hypertext as a Learning Environment in Economics: A Pedagogical Note

Instructional design in complex subjects requires the application of a sophisticated theory of cognition.* Instructional techniques and strategies that work at the knowledge and comprehension stages of cognitive development may actually inhibit learning at more advanced levels. Evaluation and synthesis require a different cognitive paradigm. The theory of cognitive flexibility is a case-based approach for the development of upper-level cognitive skills, particularly the ability to transfer knowledge to novel situations. This paper applies the theory of cognitive flexibility to instructional design in economics. An example from monetary economics illustrates the adaptation of cognitive flexibility hypertext to a knowledge management interface

Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe2_{2}As2_{2}

The iron-based high temperature superconductors exhibit a rich phase diagram reflecting a complex interplay between spin, lattice, and orbital degrees of freedom [1-4]. The nematic state observed in many of these compounds epitomizes this complexity, by entangling a real-space anisotropy in the spin fluctuation spectrum with ferro-orbital order and an orthorhombic lattice distortion [5-7]. A more subtle and much less explored facet of the interplay between these degrees of freedom arises from the sizable spin-orbit coupling present in these systems, which translates anisotropies in real space into anisotropies in spin space. Here, we present a new technique enabling nuclear magnetic resonance under precise tunable strain control, which reveals that upon application of a tetragonal symmetry-breaking strain field, the magnetic fluctuation spectrum in the paramagnetic phase of BaFe$_{2}$As$_{2}$ also acquires an anisotropic response in spin-space. Our results unveil a hitherto uncharted internal spin structure of the nematic order parameter, indicating that similar to liquid crystals, electronic nematic materials may offer a novel route to magneto-mechanical control.Comment: 11 pages, 5 figure

Graded-bandgap AlGaAs solar cells for AlGaAs/Ge cascade cells

Some p/n graded-bandgap Al(x)Ga(1-x)As solar cells were fabricated and show AMO conversion efficiencies in excess of 15 percent without antireflection (AR) coatings. The emitters of these cells are graded between 0.008 is less than or equal to x is less than or equal to 0.02 during growth of 0.25 to 0.30 micron thick layers. The keys to achieving this performance were careful selection of organometallic sources and scrubbing oxygen and water vapor from the AsH3 source. Source selection and growth were optimized using time-resolved photoluminescence. Preliminary radiation-resistance measurements show AlGaAs cells degraded less than GaAs cells at high 1 MeV electron fluences, and AlGaAs cells grown on GaAs and Ge substrates degrade comparably