The knowledge about membrane contactors is growing rapidly but is still insufficient for a reliable designing. This paper presents a new type of membrane contactors that are integrated with one of the following ways of separation by using absorbents, micelles, flocculants, functionalized polymers, molecular imprints, or other methods that are based on aggregation. The article discusses methods for designing multi-stage cascade, usually counter-current. At every stage of this cascade, relevant aggregates are retained by the membrane, while the permeate passes freely through membrane. The process takes place in the membrane boundary layer with a local cross-flow of the permeate and the retentate. So the whole system can be called a cross-counter-current. The process kinetics, k, must be coordinated with the permeate flux, J, and the rate of surface renewal of the sorbent on the membrane surface, s. This can be done by using ordinary back-flushing or relevant hydrodynamic method of sweeping, such as: turbulences, shear stresses or lifting forces. A surface renewal model has been applied to adjust the optimal process conditions to sorbent kinetics. The experimental results confirmed the correctness of the model and its suitability for design of the new type of contactors.

The article analyzes museum representations of communism in Poland from the perspective of exhibition strategies influencing the public understanding of the past. Over the past forty years, Western museums have increasingly moved away from the affirmative model of presenting the past, dominating since the nineteenth century, towards critical paradigms and even those pro-moting social activism. The analysis of Polish exhibitions devoted to recent history carried out from this perspective allows us to reveal the functions fulfilled by museum institutions in the Polish social and political reality.

A strong nostalgia for “the good old days” is a cultural phenomenon underway throughout the countries of Central and Eastern Europe. The filter of nostalgia “tames” communism, though it does not negate its absurdities and inconveniences. Only in exceptional cases does nostalgia mean a genuine desire to restore the past. Nonetheless, the very fact of a swelling nostalgia for communist times is symptomatic and indicates that despite strong public support for the narratives of the transformation in the post-communist countries, there are also narratives created in a bottom-up manner and managed by small and often private museum institutions. The musealization of post-communist nostalgia is a widespread process, but it differs in the various countries of the region. This article will analyze examples of nostalgic museum exhibitions in Poland and the former East Germany. Based on the study of these cases, the author attempts to describe the importance of such exhibitions for the public.

The article is a critical analysis of an exhibition entitled The Primer that was opened at the State Museum at Majdanek in 2003. Tomasz Pietrasiewicz’s project is not a classic historical exhibition and the aim of the article is to prove its innovative character.