On the ill/well-posedness and nonlinear instability of the magneto-geostrophic equations

We consider an active scalar equation that is motivated by a model for magneto-geostrophic dynamics and the geodynamo. We prove that the non-diffusive equation is ill-posed in the sense of Hadamard in Sobolev spaces. In contrast, the critically diffusive equation is well-posed. In this case we give an example of a steady state that is nonlinearly unstable, and hence produces a dynamo effect in the sense of an exponentially growing magnetic field.Comment: We have modified the definition of Lipschitz well-posedness, in order to allow for a possible loss in regularity of the solution ma

Experimental Investigation on the Drying of Loosely-Packed and Heterogeneous Municipal Solid Waste

In this paper, experimental investigation on convective drying of mixed municipal solid wastes was conducted. The aim of this study was to determine the effect of temperature, change in composition and particle size on the overall drying rate coefficient and mass transfer coefficient. Particle size of the samples was determined and mass losses recorded with time when the samples were dried using convective dryer. Mass losses were used to determine moisture content, drying rate coefficient and mass transfer coefficient. Experimental results showing the effect of temperature, changes in the composition of organic waste and particle size were presented

Multiphoton absorption in amyloid protein fibres

Fibrillization of peptides leads to the formation of amyloid fibres, which, when in large aggregates, are responsible for diseases such as Alzheimer's and Parkinson's. Here, we show that amyloids have strong nonlinear optical absorption, which is not present in native non-fibrillized protein. Z-scan and pump-probe experiments indicate that insulin and lysozyme β-amyloids, as well as α-synuclein fibres, exhibit either two-photon, three-photon or higher multiphoton absorption processes, depending on the wavelength of light. We propose that the enhanced multiphoton absorption is due to a cooperative mechanism involving through-space dipolar coupling between excited states of aromatic amino acids densely packed in the fibrous structures. This finding will provide the opportunity to develop nonlinear optical techniques to detect and study amyloid structures and also suggests that new protein-based materials with sizable multiphoton absorption could be designed for specific applications in nanotechnology, photonics and optoelectronics

Analyzing the Efficiency of Using Different Chemical Compositions for Intensifying the Phytoextraction Processes of Mercury and Other Heavy Metals Based on Multivariate Image Tools

A method is proposed and multifactorial experiments are carried out to determine the effectiveness of various compositions of chemical additives for intensifying the processes of phytoextraction of mercury and other heavy metals from soils. White creeping clover (lat. Trifolium repens L.) is used as the object of experiment. As a result of a systematic analysis of the results of experiments using the tools of multivariate visualization of large data arrays in the form of various diagrams (petal, line, bubble, and thermal), the following was established: the presence of a positive effect of monoethanolamine salt of thioacetic acid and sodium thiosulfate on phytoextraction of mercury; a pronounced positive effect of Trilon B on the phytoextraction of heavy metals, simultaneously accompanied by a destructive effect on the growth and development of plants; a positive effect on the condition of plants of phytohormone and iron chelate supplements; and the ability of oxyethylidene diphosphonic acid to protect plants from the negative effects of heavy metals