Coupled reactive transport modeling - the program transport

The contribution presents the program Transport, which serves to simulation of column transport experiments. Its main function is not to predict results of experiments but to compare influence of individual physical and chemical processes to the experiment results. The one-dimensional advection-diffusion model is based on Finite Volume Method; it includes the triple porosity concept, sorption, retardation, and chemical reactions simulated using connected program React from The Geochemist‘s Workbench package or PhreeqC. Due to these geochemical programs, the user has extensive possibilities of chemistry simulation during transport. The program Transport simulates not only the processes inside the column but also preparation of entering solutions and measurement methods of outgoing solution parameters. Important part of the contribution would be demonstration of results of simulation of real transport column experiments recently realized at the Technical University of Liberec

Synchronous ATM Multiplexor Propertis Verifications

There are a lot of more or less sofisticated simulating tools oriented specifically on performance evaluation ATMnetwork components in practice [1]. Along academic methods simulations on cell level, there is apparent effort to model ATM traffic on higher abstractlevel [2]. The paper is pointed on description basic properties of simulating tool designed by means of programming language C#, and on operation test of ATM multiplexor computer model [3]. Operation test is verify by means of cell loss rate and celldelay evaluation

Synchronous and Asynchronous ATM Multiplexor Properties Comparsion

The article is aimed to ATM multiplexor computer model utilisation. Based on simulation runs we try to review aspects of use a synchronous and asynchronous ATM multiplexors. ATM multiplexor is the input queuing model with three inputs. Synchronous multiplexor works without an input priority. Multiplexor inputs are served periodically. Asynchronous multiplexor model supports several queuing and priority mechanisms. CLR and CTD are basic performance parameters. Input cell flows are generated as IPP sources. The article refers to [1] which verifies the ATM synchronous multiplexor model functionality

Magnetic accumulation of kinetic energy from a reciprocating mechanical system for a dynamic behaviour improvement

This paper presents a magnetic means of accumulating kinetic energy from a traversing rod (TR) used to guide yarn during winding processes on rotor spinning machines. A passive magnetic system for accumulating kinetic energy at the reversal points of reciprocating motion is introduced, and its unique repulsive magnetic force is described in relation to the specific traversing-motion characteristic. The magnetic damping force phenomenon and preconditions for its application in the machine are also defined and discussed. We also show magnetic field optimisation by means of pole-piece geometry modification to obtain a magnetic force characteristic that closely approximates the required motion characteristic. Thus, the efficiency of kinetic-energy accumulation at the reversal points of the reciprocating motion of the TR is increased. The utilisation of an eddy-current effect on the accumulator body to apply the magnetic-damping phenomenon for vibration reduction is also described. The results of this work demonstrate the promise of the system using modern rare-earth compound-based magnets applicable not only to the studied traversing system but also to various mechanical devices as a non-contact means of reducing deformation and vibration. The developed and experimentally verified mathematical models presented here represent a useful tool for further optimisation of specific applications in the field of mechanics. (C) 2019 Elsevier Ltd. All rights reserved

Dynamics of chemical and charge transfer reactions of molecular dications: VI: Reactions of C4H32+ with Kr, Xe, H2, N2, NO, NH3, C2H2, and CH4

International audienceReactions of the hydrocarbon dication C4H32+ with a series of atomic and molecular targets (Kr, Xe, N2, NO, NH3, C2H2, and CH4) were investigated in crossed-beam scattering and guided-beam (quadrupole–octopole–quadrupole, QOQ) experiments. Non-dissociative charge transfer (NDCT), leading to the product ion C4H3+, and proton transfer (PT), leading to the product ion C4H2+, were observed. In several systems, however, dissociative charge transfer (DCT) contributed significantly to the formation of the product ion C4H2+. Full scattering diagrams of the products C4H3 and C4H2+ were obtained for the reaction with acetylene. For the other systems, energy profiles of the products close to the angular maximum were obtained. The hydrocarbon products C4H2+ and C4H3+ were scattered mostly forward, suggesting an impulsive mechanism of their formation at the collision energies investigated; the only exception was proton transfer with H2, where the energy profile of C4H2+ indicated substantial backward scattering and formation of an intermediate. From relative translational energy distributions of the products, conclusions could be made about electronic states of the hydrocarbon cations formed in these reactions

OLYMPIA-LILBID: A new Approach for Calibrating Spaceborne Hypervelocity Ice Grain Detectors Using High-Resolution Mass Spectrometry

International audienc

OLYMPIA-LILBID: A new Approach for Calibrating Spaceborne Hypervelocity Ice Grain Detectors Using High-Resolution Mass Spectrometry

International audienc