Dimensioning of aerated submerged fixed bed biofilm reactors based on a mathematical biofilm model applied to petrochemical wastewater – the link between theory and practice

The description of a biofilm mathematical model application for dimensioning an aerated fixed bed biofilm reactor (ASFBBR) for petrochemical wastewater polishing is presented. A simple one-dimensional model of biofilm, developed by P Harremöes, was chosen for this purpose. The model was calibrated and verified under conditions of oil-refinery effluent. The results of ASFBBR dimensioning on the basis of the biofilm model were compared with the bioreactor dimensions determined by application of load-based design rules for these systems (ATV standards). The differences resulting from two different approaches to ASFBBR design are analysed and discussed. The efficiency of the ASFBBR bioreactors, designed in two different ways, are then compared during dynamic simulation utilising the most advanced one-dimensional biofilm model developed by Wanner and Reichert (1996).Keywords: Biofilm modelling; petrochemical wastewater; biofilm reactor

Numerical Simulations of Torsional Alfv\'en Waves in Axisymmetric Solar Magnetic Flux Tubes

We investigate numerically Alfv\'en waves propagating along an axisymmetric and non-isothermal solar flux tube embedded in the solar atmosphere. The tube magnetic field is current-free and diverges with height, and the waves are excited by a periodic driver along the tube magnetic field lines. The main results are that the two wave variables, the velocity and magnetic field perturbations in the azimuthal direction, behave differently as a result of gradients of physical parameters along the tube. To explain these differences in the wave behavior, the time evolution of the wave variables and the resulting cutoff period for each wave variable are calculated, and used to determine regions in the solar chromosphere where strong wave reflection may occur.Comment: Submitted to Solar Physics (accepted

Spatiotemporal chaos: the microscopic perspective

PACS numbers: 05.45.JnInternational audienceExtended nonequilibrium systems can be studied in the framework of field theory or from dynamical systems perspective. Here we report numerical evidence that the sum of a well-defined number of instantaneous Lyapunov exponents for the complex Ginzburg-Landau equation is given by a simple function of the space average of the square of the macroscopic field. This relationship follows from an explicit formula for the time-dependent values of almost all the exponents

Towards symmetric scheme for superdense coding between multiparties

Recently Liu, Long, Tong and Li [Phys. Rev. A 65, 022304 (2002)] have proposed a scheme for superdense coding between multiparties. This scheme seems to be highly asymmetric in the sense that only one sender effectively exploits entanglement. We show that this scheme can be modified in order to allow more senders to benefit of the entanglement enhanced information transmission.Comment: 6 page

Classical and Quantum Fluctuation Theorems for Heat Exchange

The statistics of heat exchange between two classical or quantum finite systems initially prepared at different temperatures are shown to obey a fluctuation theorem.Comment: 4 pages, 1 included figure, to appear in Phys Rev Let

Artificial intelligence methods in diagnostics of coal-biomass blends co-combustion in pulverised coal burners

The paper presents technologies being developed in the Institute of Electronics and Information Technologies at Lublin University of Technology. They use optical sensors and artificial intelligence methods for process supervision and diagnostics. Research is aimed to develop a system allowing a parametric evaluation of the quality of pulverized coal burner operation. Due to the highly nonlinear nature of dependencies and lack of an analytical model, the artificial intelligence methods were used to estimate and classify the selected parameter, including a relatively new class of classification methods – artificial immunology algorithms. The article shows results for coal-shredded straw blends, yet the methodology may be applied for other types of blends.У роботі представлені технології, розроблені в Інституті електроніки та інформаційних технологій Люблінського технологічного університету. Вони використовують оптичні датчики та методи штучного інтелекту для контролю та діагностики процесу. Дослідження спрямовано на розробку системи, що дозволяє провести параметричну оцінку якості роботи пиловугільного пальника. Через високу нелінійну природу залежностей та відсутність аналітичної моделі для оцінки та класифікації обраного параметра були використані методи штучного інтелекту, включаючи відносно новий клас методів класифікації - алгоритми штучної імунології. У статті наведені результати для солом'яно-вугільних сумішей, але методологія може застосовуватися і для інших типів сумішей

Simulating In-situ Leaching Process Using COMSOL Multiphysics

The paper deals with simulation of in-situ uranium leaching technological process, collecting data for forecasting and leaching process control. It provides numerical simulation of uranium in-situ leaching (ISL) using Comsol Multiphysics software package application.Previous studies evaluated main hydrodynamic characteristics of wells and reservoirs, such as the coefficient of resistance and the saturation recovery; while this paper is concerned with determining the changes in process variables in the wells during operation