Session C9: HDX-Monitoring in the Wupper, a Study of Fish-Migration

Abstract: The river Wupper is one of the prioritywaters catchment areas for anadromous and potamodromous fish in the German federal state North Rhine-Westfalia. The survey took place at a small hydropower facility named “Auer Kotten” and its different fish ways and protection facilities, like a vertical slot fish pass and a natural like rockpool channel, three different bypass types and a 12 mm-horizontal screen. Sixteen HDX-antennas were installed by Institute of Applied Ecology to identify the preferred migration routes of transponder tagged fish several species. An HDX-Antenna works like an electrified coil, which creates an electro magnetic field trough to the antenna. So tagged fish enter the antenna the transponder is activated and emits an individual code, which is registered by the antenna and archived by data logger time-, location- and individual-precise. In autumn 2013 nearly three-hundred silver eels were tagged intraabdominal with transponders and released upstream the hydropower plant in the Wupper. Additionally 999 smolts of Atlantic salmon were released in spring 2014. The preferred migration corridors as well as the time for passing the different facilities could be identified by a redetection of 77 % of the silver eel and 68 % of the salmon smolts. As one of the results it was shown that neither the two surface bypasses, nor the bottom bypass were used properly by the downstream migrating fish. In opposite the vertical slot fish pass and a episodically working gate next to the trash rack screen, to send debris into the trailwater were often passed, sometimes maybe forced. Moreover wild fish of different species were caught ca. 20 km downstream the “Auer Kotten” by electro-fishing, tagged and released to get information about the preferred upstream migration routes. Most of the so far redetected fish arrived in the trailwater of the turbine outlet, while just lamprey preferred to swim into the original river bed. The results of the survey points out that the HDX-technology is perfect for field studies on the migratory behaviour of fish, even an intensive maintenance is needed f. e. to protect the installations for demages caused by high floods

Characterizing the Bulk & Flow Behaviour of LS Polymer Powders

The properties of laser sintering (LS) powders affect processability and the quality of parts manufactured. This study compared three different methods used to quantify both the static and dynamic powder properties – a Revolution Powder Analyzer, FT-4 Powder Rheometer and Hausner Ratio. The aim of the work was to identify the most reliable method to characterize powder properties in correlation to the dynamic conditions that occur during LS. The experiments focused on different particle size distributions of a cryogenically ground polyurethane powder compared to a standard polyamide 12 LS material, PA2200. The results have led to a deeper understanding regarding powder interactions and therefore serve as input for material design and quality assurance.Mechanical Engineerin

Approach of optimized planning process for exoskeleton centered workplace design

Exoskeleton technology is used in manufacturing [1] to support the manipulation of heavy goods in production specific environments. After selecting the most suitable exoskeleton for each specific workstation [2] the next key step includes the optimization of the workplace design and adjustment of exoskeletons according to the workstation’s boundaries, conditions, and constraints. The described impacts with corresponding industry examples and methods should help to understand the influence from these new technology on strategic production objectives, e.g. sustainability, reduced cost, ergonomics, flexibility, quality, and so on. KPIs and their assessment methods are performed at all production scales: beginning from high level for whole production systems, over production processes, production lines and workplace influences, which are particularly used, applied and needed on task-level. Therefore, new exoskeleton based criteria and methods for process planning are discussed intensively. They are used to monitor and especially, to optimize the productions impacts by the planning department and responsible engineers by this presented generic approach. These work present exoskeleton specific impacts define resulting and relevant criteria and corresponding assessments methods. Based on the matching methodology ExoMatch [2] a suitable exoskeleton for the presented example workplace is (pre)selected. With known impacts, the influences and criteria as mentioned before, the novel planning and design approach helps to optimize processes and the workflow by rescheduling and in consideration of suitability, strength and weaknesses of exoskleleton centered workplaces. The content and relevance of this approach is based on experience from industry

Soil biotic processes remain remarkably stable after 100-year extreme weather events in experimental grassland and heath.

Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests that extreme weather events pose threats to ecosystem functioning, particularly to nutrient cycling and biomass production. These ecosystem functions depend strongly on below-ground biotic processes, including the activity and interactions among plants, soil fauna, and micro-organisms. Here, experimental grassland and heath communities of three phytodiversity levels were exposed either to a simulated single drought or to a heavy rainfall event. Both weather manipulations were repeated for two consecutive years. The magnitude of manipulations imitated the local 100-year extreme weather event. Heavy rainfall events increased below-ground plant biomass and stimulated soil enzyme activities as well as decomposition rates for both plant communities. In contrast, extreme drought did not reduce below-ground plant biomass and root length, soil enzyme activities, and cellulose decomposition rate. The low responsiveness of the measured ecosystem properties in face of the applied weather manipulations rendered the detection of significant interactions between weather events and phytodiversity impossible. Our data indicate on the one hand the close interaction between below ground plant parameters and microbial turnover processes in soil; on the other hand it shows that the plant–soil system can buffer against extreme drought events, at last for the period of investigation

An experimental study into the effects of bulk and flow behaviour of laser sintering polymer powders on resulting part properties

The properties of parts manufactured by laser sintering (LS) are, amongst others, influenced by the packing and flow efficiencies of the powders being processed. In particular, this study investigated the influence of the bulk and flow characteristics of two thermoplastic elastomers, present in three different particle size distributions (PSD), on the resulting part properties. The powder characteristics examined, were the packing and bulk density as well as the flow efficiency of the powder samples. The resulting part properties were evaluated in terms of their mechanical properties (tensile), surface quality and density. The results helped to validate the basic input from previous studies interconnecting the powder behaviour with the properties of sintered part's. The majority of the components with increased tensile properties were manufactured with powder fractions that showed enhanced bulk density and enriched flowability. The part's surface quality demonstrated a high dependence on the packing and the surface roughness of the raw powder bulk. A strong connection between the packing density of the powder bulk and the porosity of the sintered parts has been revealed for the observed polymers. In contrast to previous studies which have rarely taken into account the characteristics of the un-sintered powder and correlated them to the properties of components fabricated by LS, this work provided a novel approach describing the interconnection between the powder behaviour and the part properties