Time filter

Source Type

Lodz, Poland

Lodz University of Technology was created in 1945 and has developed into one of the biggest technical universities in Poland. Originally located in an old factory building, today covering nearly 200,000 sq. meters in over 70 separate buildings, the majority of them situated in the main University area. Approximately 21,000 students are currently studying at the University. The educational and scientific tasks of the University are carried out by about 3,000 staff members. Wikipedia.

Heim D.,Technical University of Lodz
Renewable Energy

The role of advanced isothermal heat storage systems in buildings is discussed. A storage system encapsulated with phase change materials in which energy is absorbed in the hot period and released in the cold period is analyzed. The thermal behaviour of isothermal heat storage composites is examined using numerical techniques. Two methods of heat transfer with latent heat storage are described in the first part. Based on the initial results, the "effective heat capacity" method was selected and implemented into ESP-r. Numerical studies on the effect of isothermal storage of solar energy in specific building material components are discussed in the second part. Numerical simulations were conducted for two cases of multi-zone, highly glazed and naturally ventilated passive solar buildings. PCM-impregnated gypsum plasterboard was used as an internal room lining in the first case study and transparent insulation material combined with PCM was applied for the external south-oriented wall in the second case study. The behaviour of a TIM-PCM wall and its influence on the internal surface temperature are estimated. Air, surface and resultant temperatures are compared with a "no-PCM" case for both case studies and the diurnal and the seasonal latent heat storage effect is analyzed. © 2009 Elsevier Ltd. All rights reserved. Source

Kaminski M.M.,Technical University of Lodz
Computational Mechanics

The main aim of this paper is to present an algorithm and the solution to the nonlinear plasticity problems with random parameters. This methodology is based on the finite element method covering physical and geometrical nonlinearities and, on the other hand, on the generalized nth order stochastic perturbation method. The perturbation approach resulting from the Taylor series expansion with uncertain parameters is provided in two different ways: (i) via the straightforward differentiation of the initial incremental equation and (ii) using the modified response surface method. This methodology is illustrated with the analysis of the elasto-plastic plane trusswith randomYoung's modulus leading to the determination of the probabilistic moments by the hybrid stochastic symbolic-finite element method computations. © Springer-Verlag 2009. Source

Koniorczyk M.,Technical University of Lodz
International Journal of Heat and Mass Transfer

Crystallizing salt changes the inner pore structure of materials. MIP tests of cement mortar and brick saturated with NaCl, CaCl2, Na 2SO4 solutions were performed. The changes of porosity, pore size distribution and pore shape (ink-bottle type pores) were investigated by performing two intrusion-extrusion cycles. The crystallization pressure bursts the mezopores. During salt crystallization the additional heat is released, which must be considered in energy conservation equation of multiphase domain. The model of coupled heat, moisture and salt transport considering the salt crystallization is presented. The key factor while modeling the salt crystallization is the kinetics of salt phase change, which is approximated in the presented research by means of Freundlich non-equilibrium isotherms. In order to calculate the solution supersaturation ratio the short and long range ions interaction was taken into account applying the Pitzer model. The mathematical model was solved using FEM and FDM and some practical examples were calculated and discussed. It was proved that the higher rate order appears in the kinetic law the higher crystallization pressure might be generated. The approximation procedures were tested numerically. © 2011 Elsevier Ltd. All rights reserved. Source

Lodyga-Chruscinska E.,Technical University of Lodz
Coordination Chemistry Reviews

The 1,5-disubstituted tetrazole ring a mimetic of the cis-amide bond is an unique element modifying the ability of peptides to chelate copper(II) ions. The position of the tetrazole ring system in the peptide backbone plays a critical role in the stabilization of the metallopeptide molecule. The insertion of a tetrazole between amide groups leads to enhancing the stability of the complex and to obtaining a very effective peptide chelating agent. These findings can provide important information for modeling biologically relevant peptide-metal binding sites. Some aspects of biological activity of tetrazole modified exogenous opioid peptides in the presence of copper(II) ions are also presented in this review. © 2011 Elsevier B.V. Source

The discussion in this paper is closely related to our idea of a type-2 linguistic summary of a database presented by Niewiadomski [A. Niewiadomski, A type-2 fuzzy approach to linguistic summarization of data, IEEE Trans. Fuzzy Syst., vol.16, no.1, pp. 198213, Feb. 2008], which is intended to be an efficient tool of knowledge discovery from large databases. In that approach, we put emphasis on algorithms and applications of type-2 fuzzy sets in summarizing databases. Hence, we have implicitly assumed and considered linguistic expressions represented by sets in discrete (or even finite) universes of discourse. Now, in this paper, we discuss more thoroughly some of the properties and formal aspects of both discrete and continuous type-2 fuzzy sets that represent the elements of linguistic summaries, i.e., quantifiers, summarizers, and/or qualifiers. We underline differences between type-2 fuzzy sets in finite and in infinite (usually continuous) universes of discourse and, henceforth, between their cardinalities and similar measures, which are used in evaluating the goodness (quality) of type-2 linguistic summaries. In addition, we define new imprecision measures of linguistic expressions represented by type-2 fuzzy sets, and propose a definition of the cylindric extension of a type-2 fuzzy set. Finally, we apply these new concepts to generalize algorithms of type-2 linguistic summarization and propose some new features in comparison to our previous approach [A. Niewiadomski, A type-2 fuzzy approach to linguistic summarization of data, IEEE Trans. Fuzzy Syst., vol. 16, no. 1, pp. 198213, Feb. 2008]. © 2010 IEEE. Source

Discover hidden collaborations