Nutzungsanalyse des Bike-Sharing-Angebots in Stuttgart: Werkstattbericht zu Möglichkeiten der Nutzbarmachung frei verfügbarer Stationsdaten

Leihfahrräder prägen heutzutage in vielen Städten den öffentlichen (Verkehrs-) Raum mit - auch in Stuttgart. Bike-Sharing Systeme wie "RegioRadStuttgart" leisten einen Beitrag zur Reduktion des motorisierten Individualverkehrs und zur Entlastung des öffentlichen Personennahverkehrs. In Stuttgart wird das Angebot an Leihfahrrädern und Rückgabestationen stetig ausgebaut und optimiert. Für eine zielgerichtete Weiterentwicklung ist es wichtig die Nutzung dahingehend möglichst detailliert zu evaluieren. Dank einer frei verfügbaren Schnittstelle (API) des Anbieters können die benötigten Daten abgerufen und analysiert werden. Im vorliegenden Werkstattbericht werden Einblicke in die hierfür angewandte Methodik und Auswertungsmöglichkeiten gegeben sowie erste Ergebnisse der Nutzungsanalyse vorgestellt

Meta-Analysis of Geomorphodynamics in the Western Lower Bakırçay Plain (Aegean Region, Turkey)

The relation between human activities, climate variability, and geomorphodynamics in the Mediterranean region is widely discussed. For the western lower Bakırçay plain in the ancient Pergamon Micro-Region, geoarchaeological studies have shown changes in geomorphodynamics primarily on a site-basis. We reconstruct past geomorphodynamics in the area based on a meta-analysis of 108 (14)C-ages obtained from 25 sediment sequences mainly from colluvial and alluvial deposits by analyzing cumulative probability functions of the (14)C-ages. Accounting for biases in the database, we applied different approaches and compared the empirical probability functions with simulated functions. Reconstructed geomorphodynamics in the western lower Bakırçay plain during the Holocene principally coincide with a trend of climate-driven sensitivity to erosion and population dynamics in the eastern Mediterranean, but are also related to the local settlement history. Our data analysis shows that transformations of the Pergamon Micro-Region between the Hellenistic and Roman Imperial times is contemporary to increasing geomorphodynamics that peak in Roman Imperial times. However, a cause–effect relationship between geomorphodynamics and settlement dynamics should be further evaluated. A comparison with data from other settlement centers in Anatolia shows that a coincidence between the peak in geomorphodynamics and a peak in settlement activity are not obvious and may be influenced by soil conservation measures, preferred settlement location, and inherited soil exhaustio

Über den Wunsch lieber im Umland zu wohnen: Einblicke aus der Stuttgarter Bürgerumfrage

Stuttgarterinnen und Stuttgarter zieht es zuletzt vermehrt ins Umland. Über die Ursachen ist jedoch kaum etwas bekannt. Entsprechend befasst sich dieser Beitrag mit den Faktoren, die einen Einfluss auf den Wunsch haben lieber im Umland zu wohnen. Die Studie bedient sich dazu der Bürgerumfrage aus dem Jahr 2019. Die Beurteilung der Lebensqualität erweist sich als stärkster Treiber. Darüber hinaus stellt die Zufriedenheit mit der Wohngegend eine einflussreiche Erklärung dar. Ohne Erklärungskraft sind die berücksichtigten äußeren Bedingungen Luftqualität, Lärmbelastung, Wohnungsangebot und Mieten. Diese werden von der Bevölkerung zwar als Problem wahrgenommen, die Vorteile, die das Wohnen in Stuttgart mit sich bringt, scheinen aber zu überwiegen. Zumindest äußern jene Befragte nicht vermehrt den Wunsch lieber im Umland zu wohnen

Holocene geomorphodynamics of a rural catchment in the Pergamon micro-region (eastern Mediterranean)

The Pergamon micro-region (western Türkiye) has experienced several phases of increased geomorphodynamics during the Holocene. However, the role of local–regional human activities during a transformation between Hellenism and the Roman Imperial period and supra-regional climate fluctuations is still under discussion. Five sediment profiles from the alluvial fan of the rural Deliktaş catchment are analyzed and radiocarbon-dated to provide a sedimentological record covering the Holocene. Our results indicate seven phases of changing sediment dynamics. Five Holocene cycles of coarse- and fine-textured fan sediment deposition covered the paleochannel deposits of the Çaylak creek, and the floodplain sediments of the receiving Geyikli river which aggraded toward the piedmont during the Mid-Holocene. The landscape became stable on the Deliktaş fan and Geyikli floodplain at least ca. 4–3.4 cal ka BP as indicated by paleosols. These paleosols were again buried by fan sediments marking the first phase of accelerated geomorphodynamics during the Late Holocene. Both the local onset of human activities and the regional Mid-Holocene aridization with rapid climate changes play a role. The increased number of archeological sites and high human pressure on the environment during the Hellenistic–Roman transformation in the Deliktaş area and Pergamon micro-region were hypothesized to contribute to a phase of increased geomorphodynamic activity during the last 2.5 ka. This, however, is less apparent in our record. Our study emphasizes the importance of both, the climatic system and rural-urban cultural history, on landscape development, suggesting potential responses of locally diverse geomorphodynamics on regional-scale transformation in the eastern Mediterranean

Were climatic forcings the main driver for mid-holocene changes in settlement dynamics on the Varamin Plain (Central Iranian Plateau)?

Settlement crises in ancient cultures of Western Asia are commonly thought to be caused by climatic events such as severe droughts. However, the insufficient climate proxy situation in this region challenges the inference of clear relationships between climate and settlement dynamics. We investigate the Holocene climatic changes on the Varamin Plain in the context of the climatic history of Western Central Asia by using a transient comprehensive Earth System Model simulation (8 ka BP to pre-industrial), a high-resolution regional snapshot simulation and a synthesis of pollen-based climate reconstructions. In line with the reconstructions, the models reveal only slightly varying mean climatic conditions on the Varamin Plain but indicate substantial changes in seasonality during the Holocene. Increased precipitation during spring, combined with lower temperature and potentially stronger snow accumulation on the upstream Alborz mountains may have led to an increased water supply on the alluvial fan during the vegetation period and thus to more favourable conditions for agricultural production during the Mid-Holocene compared to modern times. According to the model, dry periods on the Central Iranian Plateau are related to particularly weak Westerly winds, fostering the subsidence in the mid-troposphere and hampering precipitation over the region. The model reveals that dry periods have spatially heterogenous manifestations, thus explaining why they do not appear in all proxy records in the wider study region. In fact, the climatic signal may depend on local environmental conditions. The interaction of the topography with the atmospheric circulation leads to additional spatial heterogeneity. Although our results provide several indications for a connection between climate and settlement dynamics, the small overall changes in moisture call into question whether climate is the main driver for settlement discontinuities on the Central Iranian Plateau. To shed further light on this issue, more high-resolution long-term proxy records are needed

Graphene-based thermopneumatic generator for on-board pressure supply of soft robots

Various fields, including medical and human interaction robots, gain advantages from the development of bioinspired soft actuators. Many recently developed grippers are pneumatics that require external pressure supply systems, thereby limiting the autonomy of these robots. This necessitates the development of scalable and efficient on-board pressure generation systems. While conventional air compression systems are hard to miniaturize, thermopneumatic systems that joule-heat a transducer material to generate pressure present a promising alternative. However, the transducer materials of previously reported thermopneumatic systems demonstrate high heat capacities and limited surface area resulting in long response times and low operation frequencies. This study presents a thermopneumatic pressure generator using aerographene, a highly porous (>99.99 %) network of interconnected graphene microtubes, as lightweight and low heat capacity transducer material. An aerographene pressurizer module (AGPM) can pressurize a reservoir of 4.2 cm3 to about ~140 mbar in 50 ms. Periodic operation of the AGPM for 10 s at 0.66 Hz can further increase the pressure in the reservoir to ~360 mbar. It is demonstrated that multiple AGPMs can be operated parallelly or in series for improved performance. For example, three parallelly operated AGPMs can generate pressure pulses of ~215 mbar. Connecting AGPMs in series increases the maximum pressure achievable by the system. It is shown that three AGPMs working in series can pressurize the reservoir to ~2000 mbar in about 2.5 min. The AGPM's minimalistic design can be easily adapted to circuit boards, making the concept a promising fit for the on-board pressure supply of soft robots.Comment: Author Affiliation: Functional Nanomaterials, Department of Materials Science, Kiel University, Germany; Corresponding Authors: Dr.-Ing. Fabian Sch\"utt ([email protected]), Prof. Dr. Rainer Adelung ([email protected]

Mid- to Late Holocene geomorphodynamics in a long-term settled mountain catchment in the Pergamon micro-region, western Turkey

From 300 BC to AD 300, the city of Pergamon underwent a profound transformation that impacted the rural settlement patterns and the concomitant geomorphodynamics. We present a geoarchaeological study in a long-term settled catchment in the Pergamon micro-region to disentangle the Holocene geomorphodynamics and triggering factors, for example, climate change and human activity. The analyses of eight radiocarbon-dated sediment profiles from the Tekkedere alluvial fan and its catchment indicate four principal sedimentation phases. Phase 1 (ca. 6.2 to 5–4 ka) is dominated by the floodplain aggradation of the receiving Bakırçay River, which is followed by the formation of floodplain soils (phase 2). Substantial geomorphodynamic changes occurred around 4 ka (phase 3), when the edge of the floodplain was buried by fan sediments of the tributary Tekkedere creek. This is attributed to supraregional aridization and rapid climate change events, superimposed by the onset of local human activities. Repeated cycles of coarse- and fine-textured fan sediments with age inversions after ca. 3.8 ka and valley infills younger than 1300 yr BP indicate the strong erosion and redeposition of sediments in phase 4. These increased geomorphodynamics may coincide with the changing settlement pattern and thus reflect human–environment interactions

Criticality Metrics for Automated Driving: A Review and Suitability Analysis of the State of the Art

The large-scale deployment of automated vehicles on public roads has the potential to vastly change the transportation modalities of today's society. Although this pursuit has been initiated decades ago, there still exist open challenges in reliably ensuring that such vehicles operate safely in open contexts. While functional safety is a well-established concept, the question of measuring the behavioral safety of a vehicle remains subject to research. One way to both objectively and computationally analyze traffic conflicts is the development and utilization of so-called criticality metrics. Contemporary approaches have leveraged the potential of criticality metrics in various applications related to automated driving, e.g. for computationally assessing the dynamic risk or filtering large data sets to build scenario catalogs. As a prerequisite to systematically choose adequate criticality metrics for such applications, we extensively review the state of the art of criticality metrics, their properties, and their applications in the context of automated driving. Based on this review, we propose a suitability analysis as a methodical tool to be used by practitioners. Both the proposed method and the state of the art review can then be harnessed to select well-suited measurement tools that cover an application's requirements, as demonstrated by an exemplary execution of the analysis. Ultimately, efficient, valid, and reliable measurements of an automated vehicle's safety performance are a key requirement for demonstrating its trustworthiness

On the plasma permeability of highly porous ceramic framework materials using polymers as marker materials

Highly porous framework materials are of large interest due to their broad potential for application, for example, as sensors or catalysts. A new approach is presented to investigate, how deep plasma species can penetrate such materials. For this purpose, a polymer (ethylene propylene diene monomere rubber) is used as marker material and covered with the porous material during plasma exposure. Water contact-angle and X-ray photoelectron spectroscopy measurements are used to identify changes in the polymer surface, originating from the interaction of plasma species with the polymer. The method is demonstrated by studying the plasma permeability of tetrapodal zinc oxide framework materials with a porosity of about 90% in an oxygen low-pressure capacitively coupled plasma. Significant differences in the penetration depth ranging from roughly 1.6–4 mm are found for different densities of the material and different treatment conditions

Development and analysis of the Soil Water Infiltration Global database

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it