Salinity-Induced Density Stratification in Near-Laminar Open-Channel Flows

Salt tracer experiments are a cost-effective tool widely used in studies of flow and transport in free surface flows. Whereas in a large majority of rivers and streams, fully turbulent conditions achieve rapid vertical mixing of injected tracers, this is not necessarily the case with very low Reynolds number flows as encountered e.g., in wetland ponds. There, often laminar to near-laminar transitional flow regimes prevail, and the fact that solutions of elevated salinity are distinctly heavier than water may result in the development of stable density layers, trapping part of the salt tracer and distorting the breakthrough curve recorded at the outlet. In this study, the conditions under which density stratification develops due to salt injection are analyzed, and a criterion is presented which permits an intended salt tracer experiment to be judged at the planning stage already.     

Learning from New Product Development Projects: An Exploratory Study

Knowledge generation is a cornerstone of new product development, and post‐project reviews (PPRs) are widely recognized as a facilitator of project‐to‐project learning. Empirical research on PPRs is sparse, so this paper describes four in‐depth exploratory case studies that look at how PPRs are conducted and the learning that can result. The results indicate that appropriately managed PPRs can make a significant contribution to knowledge generation and exchange. In addition, the study indicates the urgent need for more research into this important area.     

Relative Numerousness Judgment and Summation in Young and Old Western Lowland Gorillas.

The relationship between age, relative numerousness judgment, and summation was investigated in 11 Western lowland gorillas (Gorilla gorilla gorilla). Experiments 1 and 2 evaluated the gorillas' ability to select the larger of 2 food quantities before and with training. The majority of gorillas did not reliably select the larger quantity in Experiment 1 until receiving training to do so in Experiment 2. Experiment 3 evaluated their ability to select the larger of 2 pairs of quantities. All gorillas selected the larger pair more often than chance, and the old were less accurate and slower than were the young. For most gorillas, performance in relative numerousness judgment with training and summation was comparable with previous reports in chimpanzees and orangutans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design and performance of solar powered absorption cooling systems in office buildings

The paper contributes to the system design of solar thermal absorption chillers. A full simulation model was developed for absorption cooling systems, combined with a stratified storage tank, steady-state or dynamic collector model and hourly resolved building loads. The model was validated with experimental data from various solar cooling plants.As the absorption chillers can be operated at reduced generator temperatures under partial load conditions, the control strategy has a strong influence on the solar thermal system design and performance. It could be shown that buildings with the same maximum cooling load, but very different load time series, require collector areas varying by more than a factor 2 to achieve the same solar fraction. Depending on control strategy, recooling temperature levels, location and cooling load time series, between 1.7 and 3.6 m² vacuum tube collectors per kW cooling load are required to cover 80% of the cooling load.The cost analysis shows that Southern European locations with higher cooling energy demand lead to significantly lower costs. For long operation hours, cooling costs are around 200 € MWh⁻¹ and about 280 € MWh⁻¹ for buildings with lower internal gains and shorter cooling periods. For a Southern German climate, the costs are more than double.     

Purification and characterisation of relevant natural and recombinant apple allergens

Apple (Malus domestica) is the most widely cultivated fruit crop in Europe and frequently causes allergic reactions with a variable degree of severity. So far, four apple allergens Mal d 1, Mal d 2, Mal d 3 and Mal d 4 have been identified. Mal d 1, a Bet v 1 related allergen, and Mal d 4, apple profilin, are sensitive to proteolytic degradation, whereas Mal d 2, a thaumatin-like protein and Mal d 3, a nonspecific lipid transfer protein, are rather stable to proteolytic processes. Mal d 1 and Mal d 4 were purified after expression in Escherichia coli expression system, while Mal d 2 and Mal d 3 were purified from apple fruit tissue. All purified proteins were subjected to detailed physicochemical characterisation to confirm their structural integrity and maintained IgE binding capacity. Detailed investigations of carbohydrate moieties of Mal d 2 demonstrated their involvement in the overall IgE binding capacity of this allergen. It was concluded that the folded structure and IgE binding capacity of all four allergens were preserved during purification.