Analysis of photometric observations of the variable HS 2231+2441

The paper analyzes photometric observations and determines the parameters of a young precataclesmic variable with the subdwarf B, HS 2231+2441. During differential processing of observations, the light curves of the object in the V and R bands were constructed. Their model analysis was carried using models of irradiated stellar atmospheres with the combined consideration of the effects of reflection and nonsphericity of the components. As a result of the optimal description of the observed light curves, some of the parameters of the system were redefined: the inclination angle and semi-major axis of the orbit, the radii and masses of the components of HS 2231+2441. The resulting set of parameters is in good agreement with modern ideas about the characteristics of such systems.

Optimal approaches to manage power system decarbonation

To overcome the negative environemental impact of the actual power system, an optimal description of quasi-static electromagnetics relying on a reversible interpretation of the Faraday’s law is given. Due to the overabundance of carbon-free energy sources, this description makes it possible to consider an evolution towards an energy system favoring low-carbon technologies. The management for changing is then explored through a simplified linear-programming problem and an analogy with phase transitions in physics is drawn.

Equilibrium studies of the sequential removal of Reactive Blue 19 dye and lead (II) on rapeseed waste

This study investigates the effect of pollutant initial concentration on the sequential biosorptive removal of Reactive blue 19 dye and Pb(II) ions on rapeseed waste. The initial concentrations of both organic and inorganic pollutants positively influence the sequential biosorption of the dye and metal ion under study on rapeseed meal waste. The most significant increase was found in the removal of Reactive blue 19 dye by using rapeseed previously loaded with lead ions. In this case, the increase of the initial concentration from 15 mg/L to 100 mg/L results in an increase of the biosorption capacity of almost 6.8 times. Taking into account the frequent quantification of the wastewater treatment efficiency through the biosorption capacity generated from equilibrium studies, the obtained experimental data have been modelled by using five two-parameters (Langmuir, Freundlich, Halsey, Temkin and Harkins-Jura) and five three-parameters (Sips, Redlich-Peterson, Toth, modified BET and Hill) nonlinear isotherms. Linearized forms of Langmuir and Freundlich were also discussed. The optimal description for the sequential biosorption of the reactive dye is provided by the Hill and Langmuir isotherms, whereas the retention of lead on rapeseed waste is provided by the Freundlich isotherm.

A Biotracing Model of Salmonella in the Pork Production Chain

In biotracing systems, downstream chain information and model-based approaches are used to trace the sources of microbial contamination in a food chain. This article includes the results of a biotracing model for Salmonella in the pork slaughter process chain. A Bayesian belief network model was used in which information on the Salmonella level at different locations in the slaughterhouse were used in combination with prior knowledge about the dynamics of Salmonella throughout the slaughter line. Data collected in a Dutch slaughterhouse were used to specify prior beliefs about the model inputs and to iteratively refine the distributions of the parameters in the model to obtain an optimal description of that specific slaughterhouse. The primary purpose of the model is to trace the sources of contamination for individual Salmonella-positive carcasses at the end of the slaughter line. The model results indicated that house flora on or in the carcass splitter was the source of contamination for many carcasses, especially for those that carried contamination on the cutting side. The results also indicated that the parameter values of the model may be subject to temporal variation and can be used as a tool to provide estimates of such trends. This model illustrates the concept of biotracing, gives insight into the dynamics of Salmonella in the slaughter line, and indicates the sites in the line where data collection is most effective for biotracing. This biotracing model was implemented as an interactive computer application, which is a step in the process toward an operational biotracing system by which a stakeholder can initiate immediate responses to Salmonella contamination and other hazards in the pork slaughterhouse.