| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5641 |
| title | Experimental verification of the contaminant transport in the aquifer incorporating advection, dispersion and sorption processes |
| authors | Andrzej Aniszewski |
| pages | 195 — 212 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem52str195.pdf |
| keywords | advection, diffusion, reversible sorption, contaminant transport, numerical solution, site verification |
| affiliations | - Technical University of Szczecin, Chair of Sanitary Engineering, al. Piastów 50a, 70-310 Szczecin, Poland, e-mail: andrzej.aniszewski@ps.pl
|
| abstracts | The paper addresses the site verification of the practical 2D-mathematical model of conservative and passive contaminant transport in the groundwater stream incorporating also, except the advection and dispersion processes, the source (negative) term of reversible sorption. It is generally assumed, that local equilibrium conditions exist between the aqueous (free)-phase and the solid (sorption)-phase for the sorption process being considered. For such an equilibrium-controlled state, the term of reversible sorption can be described by the linear or non-linear adsorption (desorption) isotherms in relation to statics of this process. In this analysis the Freundlich equilibrium isotherm was accepted, which is also widely applied in practice. In this 2D-mathematical model the numerical solution (using the finite difference method), calculated values of the longitudinal and transverse dispersion coefficients (Dx, Dy) as well as the adsorption parameters (K, N) were used. To facilitate the numerical solutions, the modified calculation programme "PCCS-1" was also worked out. The calculated maximal values of chloride concentrations based on this model were compared with the measured chloride concentrations in those chosen for this verification piezometers installed in the natural aquifer. The calculated values of relative deviations (between the calculated and the measured concentrations in relation to the measured concentrations) proved the sufficient accuracy of the numerical solution of the contaminant transport model in groundwater stream presented with the non-linear source term representing the adsorption process. The calculations proved also the low adsorption capacity in the aquifer chosen for verification. The site verification of the presented 2D-mathematical model of contaminant transport in ground medium proved the possibility of practical usage of this model for engineering calculations of the contaminant concentration fields in the natural aquifers. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5642 |
| title | Theoretical analysis on experiments in transformation of deep-water-waves |
| authors | Wilde P. |
| pages | 213 — 242 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem52str213.pdf |
| keywords | water waves, stability, transformation, wave groups, Schrödinger differential equation |
| affiliations | - Institute of Hydro-Engineering of the Polish Academy of Sciences, ul. Kościerska 7, 80-328 Gdańsk, Poland, e-mail: p_wilde@ibwpan.gda.pl
|
| abstracts | The aim of the paper is to discuss the usefulness of the non-linear Schrödinger differential equation in the study of transformations of progressive deep water waves. Its solution compared with a regular Stokes type wave is essentially restricted to the first order approximation of the second one. The difference is that the Schrödinger equation introduces the concepts of a carrier wave and complex amplitude. In this way the dispersion relation of the third order Stokes expansion is taken into account. The analysis starts with regular, non breaking Stokes waves with large amplitudes as measured in our laboratory. The third order approximation is considered and compared with the corresponding solution of the Schrödinger equation. Then small periodic modifications are introduced in the time series fed into the control system of the generator. The approximation by trigonometric series is applied and the simplified analysis of superposition of very small modifications is used (higher powers of modifications are neglected). The Schrödinger non-linear equation is used in this analysis. The comparison of experimental and calculated envelopes is good, but for the surface elevations in space it is not as good. The approximation by trigonometric series is also applied to study the case of larger modifications. Finally the solutions of the Schrödinger equation corresponding to perfect solitons, are compared with the experimental data for cases where the measured surface elevations look almost like periodic solitons. This gives a reasonable approximation of the real behaviour in a very short space interval. It is not easy to get a good numerical description for the wave problem discussed as the waves are physically unstable. The results of the presented research will be used to establish an effective numerical procedure, stress the approximations introduced by the application of the Schrödinger differential equation and show how the theoretical solutions should be compared with the measured data. |
| attributes | [reviewed] [scientific] |
| language | en |
| points | 6 |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5643 |
| title | Modelling of concrete behaviour with a non-local continuum damage approach |
| authors | Jerzy Bobiński, Jacek Tejchman |
| pages | 243 — 263 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem52str243.pdf |
| keywords | characteristic length, concrete, crack, damage model, FEM, non-local theory |
| affiliations | - Gdańsk University of Technology Faculty of Civil and Environmental Engineering 80-952 Gdańsk, ul. Narutowicza 11/12, Poland, e-mails: bobin@pg.gda.pl, tejchmk@pg.gda.pl
|
| abstracts | The paper presents FE-results on the behaviour of concrete under plane strain conditions. The material was modelled using a simple isotropic damage continuum model. The model was enriched by non-local terms to avoid a pathological mesh-sensitivity and to obtain a well-posed rate boundary value problem. The constitutive model was used to simulate localization of deformation in 3 benchmark problems: a double-edge notched specimen under uniaxial tension and a notched beam under three- and four-point bending. Attention was laid on the effect of a characteristic length on the load-displacement curves and strain localization. The FE-results were compared with experiments and other numerical studies. |
| attributes | [reviewed] [scientific] |
| language | en |
| ATTRIBUTE | VALUE |
|---|
| type | A |
| database id | 5644 |
| title | Rheological properties of building gypsum fresh pastes |
| authors | Stanisław Klin |
| pages | 265 — 282 |
| full text link | http://www.ibwpan.gda.pl/storage/app/media/ahem/ahem52str265.pdf |
| keywords | gypsum, gypsum plaster, rheology, plastic viscosity, yield stress |
| affiliations | - Agricultural University of Wrocław, Institute of Environmental Engineering, Pl. Grunwaldzki 24, 50-363 Wrocław, Poland, e-mail: sklin@iis.ar.wroc.pl
|
| abstracts | The study presents results of laboratory tests of rheological properties of fresh pastes made of building gypsum at a wide range of water-gypsum ratios W/G = 0.4 - 1.5. The tests were carried out in a rotary-type viscosimeter RHEOTEST-2. The rheograms characterize dynamic changes in shearing stress τ of the gypsum pastes in the course of setting. By the addition of setting retarders rheostable gypsum pastes were obtained for the period of the experiments, which enabled the taking of rheograms of the shearing stress τ, described by analytical functions based on Bingham's and Herschel-Bulkley's plastic bodies. There were determined relations between the yield stress τ0 as well as plastic viscosity η and the W/G ratios. The results have considerable heuristic and practical values for rheology of fresh gypsum pastes. |
| attributes | [reviewed] [scientific] |
| language | en |
