Bank Retreat and Streambank Morphology of a Meandering River during Summer and Single Flood Events in Northern Norway

In recent years, advanced methods for measuring riverbank migration have been used to understand the process of river planform evolution. However, the role of the so-called outer secondary cell in the hydraulic pattern in bank erosion remains unclear. For this purpose, a natural river meander with high curvature bends and steep riverbanks was chosen to quantify bank migration by high-resolution terrestrial laser scanning of three patches along two river bends in four time intervals. The first two time intervals were seasonal, from spring to autumn, and with relatively few water level changes, whereas the third and fourth time intervals were short, just before and after single flood peak events. The yielded point clouds were filtered and digital elevation models (DEMs) were created. These DEMs were used to analyze bank retreat, riverbank morphology, and slope gradient changes in order to understand the role of the outer secondary cell in these processes. In addition, it is shown that storm events causing short peaks in river discharge are less important for river migration than longer-lasting medium discharge

Bank Retreat and Streambank Morphology of a Meandering River during Summer and Single Flood Events in Northern Norway

In recent years, advanced methods for measuring riverbank migration have been used to understand the process of river planform evolution. However, the role of the so-called outer secondary cell in the hydraulic pattern in bank erosion remains unclear. For this purpose, a natural river meander with high curvature bends and steep riverbanks was chosen to quantify bank migration by high-resolution terrestrial laser scanning of three patches along two river bends in four time intervals. The first two time intervals were seasonal, from spring to autumn, and with relatively few water level changes, whereas the third and fourth time intervals were short, just before and after single flood peak events. The yielded point clouds were filtered and digital elevation models (DEMs) were created. These DEMs were used to analyze bank retreat, riverbank morphology, and slope gradient changes in order to understand the role of the outer secondary cell in these processes. In addition, it is shown that storm events causing short peaks in river discharge are less important for river migration than longer-lasting medium discharge

Freeze-drying with structured sublimation fronts : visualization with neutron imaging

The particular structure of the sublimation front in vacuum freeze-drying of porous media is, in most situations, not accessible at the pore scale. The classical measurement techniques access the process only globally. Knowledge about the structure of the front, however, is necessary for prescriptive analysis of freeze-drying, as it dictates not only drying velocity, drying time, and overall energy consumption, but also the material properties after drying. This is especially relevant in situations in which the freeze-drying process is carried out close to the collapse temperature of the product. We, therefore, study the sublimation of ice with neutron tomography and analyze the spatial formation of the dry space using the example of frozen cylindrical maltodextrin with drying parameters at the limit of material collapse. We show that the sublimation front forms unique fractal structures that differ strongly from the usual form of a flat front. Distinct dry fingers covering the sample, in addition to a fractal peripheral sublimation front, were observed. The findings are important for the understanding of freeze-drying processes and will serve as a basis for the development of microscale models of freeze-drying.DFG-Publikationsfonds 202

Incidence of infections due to third generation cephalosporin-resistant Enterobacteriaceae - a prospective multicentre cohort study in six German university hospitals

BackgroundInfections caused by third generation cephalosporin-resistant Enterobacteriaceae (3GCREB) are an increasing healthcare problem. We aim to describe the 3GCREB infection incidence and compare it to prevalence upon admission. In addition, we aim to describe infections caused by 3GCREB, which are also carbapenem resistant (CRE).MethodsIn 2014-2015, we performed prospective 3GCREB surveillance in clinically relevant patient specimens (screening specimens excluded). Infections counted as hospital-acquired (HAI) when the 3GCREB was detected after the third day following admission, otherwise as community-acquired infection (CAI).ResultsOf 578,420 hospitalized patients under surveillance, 3367 had a 3GCREB infection (0.58%). We observed a similar 3GCREB CAI and HAI incidence (0.28 and 0.31 per 100 patients, respectively). The most frequent pathogen was 3GCR E. coli, in CAI and HAI (0.15 and 0.12 per 100 patients). We observed a CRE CAI incidence of 0.006 and a HAI incidence of 0.008 per 100 patients (0.014 per 1000 patient days).ConclusionsComparing the known 3GCREB admission prevalence of the participating hospitals (9.5%) with the percentage of patients with a 3GCREB infection (0.58%), we conclude the prevalence of 3GCREB in university hospitals to be about 16 times higher than suggested when only patients with 3GCREB infections are considered. Moreover, we find the HAI and CAI incidence caused by CRE in Germany to be relatively low