Low Cost GPS-Based System for Site-Specific Farming at Flat Terrains - Case Study

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): Low Cost GPS-Based System for Site-Specific Farming at Flat Terrains - Case Study. Manuscript ATOE 07 004. Vol. IX. July, 2007

Gas maldistribution in a fermenter stirred with multiple turbines

The study is focused on modeling of gas maldistribution of aerated liquid systems in a multiple impeller bioreactor. The phenomenon may or may not depend on column design. The latter case is dependent merely on bed fluid dynamics and could be treated by using the methodology of the residence time distribution (RTD) theory. Accordingly, a specific methodology is proposed, as follows: the fermenter has been modelled as a reactor network involving a combination of zones representing basic ideal flow patterns. The methodology is based on the wide-spread experimental gas tracer technique extended by a new systemic identification approach. The approach is based on a Mellinmodification of the Laplace transform over the relevant equations. The method allows zero-time solutions for identification analysis. Unlike the diffusion model approximation, the technique considered allows exact approximation of the RTD curves with circulation. The proposed transfer function represents adequately the bioreactor gas maldistribution thus allowing fast overview of the studied reaction and prompt feed back control on the physical situation

Direct Energy Production From Hydrogen Sulfide in Black Sea Water - Electrochemical Study

A sulfide driven fuel cell is proposed to clean the Black Sea with the simultaneous A sulfide driven fuel cell is proposed to clean the Black Sea with the simultaneous production of energy. The process is hopeful even at low sulfide concentrations, i.e.10 to 25 mg/l being close to the ones in the Black Sea water. The main problem for the practical application of this type of fuel cell are the low current and power densities. The measurement of the generated electric current compared to the sulfide depletion show that the most probable anode reaction is oxidation of sulfide to sulfate. It is evident that parasite competitive reactions oxidation of sulfide occurs in the anode compartment of the fuel cell. The pH measurements shows that the transfer of hydroxylic anions from the cathodic compartment to the anodic one across the separating membrane is not fast enough to compensate its drop in the anode compartment

Chern - Simons Gauge Field Theory of Two - Dimensional Ferromagnets

A Chern-Simons gauged Nonlinear Schr\"odinger Equation is derived from the continuous Heisenberg model in 2+1 dimensions. The corresponding planar magnets can be analyzed whithin the anyon theory. Thus, we show that static magnetic vortices correspond to the self-dual Chern - Simons solitons and are described by the Liouville equation. The related magnetic topological charge is associated with the electric charge of anyons. Furthermore, vortex - antivortex configurations are described by the sinh-Gordon equation and its conformally invariant extension. Physical consequences of these results are discussed.Comment: 15 pages, Plain TeX, Lecce, June 199

A Comparative Investigation of an in vitro and Clinical Test of the Bifidogenic Effect of an Infant Formula

The bifidogenic effect of an infant formula supplemented with inulin and fructooligosaccharides (4.0 g/l) was examined clinically and in vitro, and compared that of mature breast milk. In a 28-day clinical study, fecal samples of 21 infants, divided into two groups: one receiving the infant formula and the other breast milk, were microbiologically and biochemically examined. In the in vitro investigation, microbiological and biochemical changes in the infant formula and breast milk induced by the action of bifidobacteria isolated from infant feces were examined. There were no significant differences in the fecal numbers of lactobacilli, total aerobes, anaerobes or yeasts and fungi. In contrast, the bifidobacteria numbers in the stools increased significantly during the study in the infants receiving the supplemented formula. The comparative in vitro test showed that the bifidogenic effect was similar for infant formula and breast milk in terms of the number of bifidobacteria. Consumption of infant formula with added inulin and fructooligosaccharides stimulated the bifidogenic effect, both clinically and in vitro. The in vitro test can quickly and objectively determine the bifidogenic effect of infant formula and indicate their quality. However, a clinical test is necessary to determine the acceptance and biological value of infant formula