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Aufsatz

Negotiating weights for burden sharing rules in international climate negotiations: an empirical analysis
(2020-11-03)
We have collected data from a world-wide survey among COP delegates to empirically investigate preferences for certain burden sharing rules among key groups in a setting that reflects the possibility of observing concessions from negotiating partners. In our survey, the participants had the opportunity to select and combine up to eight (pre-defined) burden sharing rules and to assign relative weights to the selected rules in their preferred bundle. We examine whether such a mechanism helps to overcome the currently ...
Aufsatz

Wet sieving versus dry crushing: Soil microaggregates reveal different physical structure, bacterial diversity and organic matter composition in a clay gradient
(2020-06-18)
Soil microaggregates contain particles of different sizes, which may affect their potential to store organic carbon (OC). A variety of methods can be used to isolate microaggregates from the larger soil structures, among which wet sieving approaches are widely employed. We developed a novel dry crushing method that isolates microaggregates along failure planes due to mechanical stresses rather than hydraulic pressures and compared the mechanical stability, OC contents and microbial community composition between ...
Aufsatz

Annual industrial and commercial heat load profiles: modeling based on k-Means clustering and regression analysis
(2021-05-20)
An accurate method to predict annual heat load profiles is fundamental to many studies, e.g., preliminary design or potential studies on renewable heating systems. This study presents a method to predict annual heat load profiles with a daily resolution for industry and commerce, based on an analysis of 797 natural gas load profiles (≥1.5 GWh/a). To derive heat load profiles, these natural gas load profiles are normalized and those with a potentially non-linear relationship between heat demand and natural gas consumption ...
Aufsatz

Disentangling the complexity of socio-cultural values of temporary rivers
(2021-05-20)
In the last decade, an awareness towards temporary rivers has increased globally in response to drying climates and growing human demand for water. However, social perceptions of temporary rivers have rarely been incorporated in their science and management. In this study, we advance an understanding of the socio-cultural values of temporary rivers principally in a European context. We used an ecosystem services-based approach for a participatory and deliberative exercise with 16 researchers and managers. Our results ...
Aufsatz

Seasonal effects in the long-term correction of short-term wind measurements using reanalysis data
(2021-11-21)
Measure–correlate–predict (MCP) approaches are often used to correct wind measurements to the long-term wind conditions on-site. This paper investigates systematic errors in MCP-based long-term corrections which occur if the measurement on-site covers only a few months (seasonal biases). In this context, two common linear MCP methods are tested and compared with regard to accuracy in mean, variance, and turbine energy production – namely, variance ratio (VR) and linear regression with residuals (LR). Wind measurement ...
Aufsatz

Energy and Exergy Based Thermal Analysis of a Solar Assisted Yogurt Processing Unit
(2022-06-01)
Energy and exergy based thermal analysis was conducted for a solar assisted yogurt processing unit capable of performing required heating and cooling processes in a single container. The system consisted of a round-shaped fermentation chamber connected with a hot water storage tank coupled with an evacuated tube collector and a pillow plate at the bottom of the chamber for cooling through a PV-operated refrigeration unit. Experiments were conducted using three different volumes of cow’s raw milk (30, 40, and 50 L). ...
Aufsatz

Static Grid Equivalent Models Based on Artificial Neural Networks
(2021-12-30)
Power systems are rapidly and significantly changing due to the increasing penetration of distributed energy resources (DERs) and the rapid growth of widespread grid interconnections. An increasing number of grid operators is thus interested in the reduced equivalent representation of a large, interconnected power system to reduce the amount of required computational resources and data exchange, e.g., between grid operators. However, state-of-the-art grid equivalents become more and more inapplicable since they are ...
Aufsatz

Extended Nodal Admittance Matrix Based Stability Analysis of HVDC Connected AC Grids
(2022-05-23)
Motivated by emerging HVDC oscillation issues resulted from the interaction with AC grids, impedance-based stability analysis has become an attractive approach in the de-risking studies due to the capability of black-box modelling and clear physical meaning. However, impedance-based stability assessment of HVDC is typically conducted either from the AC side or from the DC side, without fully considering both AC and DC grid dynamics, thus impairs evaluation accuracy. In this paper, the nodal admittance matrix based ...
Aufsatz

Cold Load Pickup Model Adequacy for Power System Restoration Studies
(2022-10-18)
When a grid section is re-energized after an interruption, the load behaviour can be significantly different from normal operation. In this manuscript, the impact of the phenomenon—known as cold load pickup—is investigated by evaluating 31 time series measured after network outages in Austria and Germany. Its impact on power system restoration and the adequacy of the most common type of simplified model for such investigations is assessed by the time domain simulation of a restoration setting involving the parallel ...