The purpose of this Guest Editorial is to suggest a theoretically sound and empirically supported skeletal narrative for the place of German cities in the geohistory of Europe.
1 Which First Geography of Cities in Europe?
We have been bequeathed alternative stories from Max Weber and Henri Pirenne for the urban geography of medieval European cities. Weber’s more political approach offered a historical global view contrasting the ‘occidental’ city where ‘city air makes man free’ to the ‘oriental city’ where this was not the case. His historical geography of
The selected techniques were reviewed and their technological aspects were characterized in the context of multi-phase flow for biogas production. The conditions of anaerobic fermentation for pig slurry in a mono-substrate reactor with skeleton bed were analysed. The required technical and technological criteria for producing raw biogas were indicated.
Design and construction of the mono-substrate model, biogas flow reactor, developed for cooperation with livestock buildings of various sizes and power from 2.5 kW to 40 kW. The installation has the form of a sealed fermentation tank filled with a skeletal deposit constituting a peculiar spatial system with regular shapes and a rough surface.
Incorporating a plant in such a production cycle that enables the entire slurry stream to be directed from the cowshed or pig house underrun channels to the reactor operating in the flow mode, where anaerobic digestion will take place, allows to obtain a biogas.
The paper presents preliminary results of experimental investigations in the field of hydrodynamic substrate mixing system for biogas flow assessment by the adhesive bed in the context of biogas production. The aim of the study was to assessment and shows the influence of the Reynolds number on the biogas resistance factor for the fermentation process in mono-substrate reactor with adhesive deposit. The measurement results indicate a clear effect of the Reynolds number in relation to the descending flow resistance coefficient for the adhesive bed.
Ecol. Manag., 109: 1-7.
Kucza J., 2005. Teoretyczne i praktyczne aspekty obliczania zapasu wody w glebach leśnych. Cz. 2. Gleby szkieletowe. (Theoretical and practical aspects of calculating water resources in forest soils. Part II. Skeletal soils). Sylwan 149, 10: 35-46.
Kucza J., 2007. Właściwości hydrologiczne materii organicznej gleb leśnych na przykładzie gleb pod świerczynami istebniańskimi. (Hydrological properties of organic matter of forest soils as exemplified by soils under Istebna stands of Norway spruce