Untersuchungen zum Fuellverhalten von mikrostrukturierten Formteilen beim Mikrospritzgiessen von Polymerschmelzen

The use of injection moulding for micro technology products is increasing steadily due to its economical and technical importance. A lot of products for medical, telecommunication or biotechnology applications require high precision combined with low production costs. LIGA technology allows the production of moulds for parts with sub millimetre precision. Micro injection moulding combines high automation and the processing of engineering polymers. Within this research the process of filling micro structured parts is investigated. Micro structured parts are parts with regular injection moulding size containing sections on the part which are structured in the sub-millimetre range. Further on software tools for the simulation of the filling process are used and investigated to evaluate the usability of such tools for micro injection moulding. This results lead to the definition of new specifications for simulation tools. (orig.)SIGLEAvailable from TIB Hannover: RA 5476(19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Understanding the Impact of Liquid Organic Fertilisation and Associated Application Techniques on N₂, N₂O and CO₂ Fluxes from Agricultural Soils

The prediction of liquid manure effects on N transformations in soils and the associated N2O and N2 fluxes is poor because previous investigations have mostly excluded N2. The objectives of this study were thus to quantify N2, N2O and CO2 fluxes, the source processes of N2O, N2O reduction and the depth distribution of moisture, NO3−, NH4+, water-extractable organic carbon concentration and pH in a laboratory incubation study with sandy arable soil using 15N tracing to quantify N processes and gaseous fluxes. The soil was amended with and without artificial slurry in various manure treatments (control, surface and injected) and incubated for 10 days at varying moisture levels, where the depth distribution of control parameters was determined twice during the experiment. Manure application was found to increase N2 and N2O fluxes from denitrification, with the highest fluxes occurring in the wet manure injection treatment (33 ± 32 mg N m−2 d−1 and 36.1 ± 39.1 mg N m−2 d−1, respectively), confirming that manure injection under wet conditions enhances denitrification and possibly also N2O fluxes. This study concluded that the current dataset is suitable as a first step towards improving the capability of biogeochemical models to predict manure application effects, but further studies with more soils and refined experiments are needed