Breaking wave kinematics, local pressures, and forces on a tripod support structure

This paper presents breaking wave loads on a tripod structure from physical model tests and numerical simulations. The large scale model tests (1:12) are described as well as the validation of the three dimensional numerical model by comparison of CFD wave gauge data and pressures with measurements in the large wave flume inside and outside the impact area. Subsequently, the impact areas due to a broken wave, a curled wave front as well as for wave breaking directly at the structure with a partly vertical wave front are compared to each other. Line forces in terms of slamming coefficients with variation in time and space are derived from CFD results and the velocity distribution is presented at the onset of wave breaking. Finally, the results are briefly discussed in comparison to other slamming studies.German Federal Environment Ministry (BMU)/GIGAWIN

Comparison of drag and inertia coefficients for a circular cylinder in random waves derived from different methods

[No abstract available

Influence of Structural Elements on the Spatial Sediment Displacement around a Jacket-Type Offshore Foundation

This research advances the understanding of jacket-type platform induced local and global erosion and deposition processes for combined wave–current conditions. To this end, a laboratory study was carried out comparing the equilibrium scour depth for two structural designs that are differentiated in the geometrical distance of the structure’s lowest node to the seabed. Measurements of local scour depths over time have been conducted with echo sounding transducers. An empirical approach is proposed to predict the final scour depths as a function of the node distance to the seabed. Additionally, 3D laser scans have been performed to obtain the digital elevation model of the surrounding sediment bed. Novel methodologies were developed to describe and easily compare the relative volume change of the sediment bed per surface area due to structure–seabed interaction, enabling spatial analyses of highly complex erosion and deposition patterns. The seabed sediment mobility around the structure is found to be highly sensitive to a change in node distance. The decrease of the node distance results in a higher erosion depth of sediment underneath the structure of up to 26%, especially for current-dominated conditions, as well as an increased deposition of sediment downstream of the structure over a distance of up to 6.5 times the footprint length. The results of this study highlight the requirement to consider the interaction of the structure with the surrounding seabed within the design process of offshore structures, to mitigate potential impacts on the marine environment stemming from the extensive sediment displacement and increased sediment mobility

Synergism of microwaves and ultrasound for advanced biorefineries

AbstractConventional energy sources are limited and non-renewable and their consumption contributes to greenhouse gas emissions. The world is in need of advanced biorefineries to meet ever growing energy demands associated with population growth and economic development. An advanced biorefinery should use renewable and sustainable (both in quality and quantity) feedstock that gives rise to higher energy gains with minimum non-renewable energy and resource consumption. Development of advanced biorefineries is currently encircled by two major issues. The first issue is to ensure adequate biofuel feedstock supplies while the second issue is to develop resource-efficient technologies for the feedstock conversion to maximize energy and economic and environmental benefits. While microalgae, microbial derived oils, and agricultural biomass and other energy crops show great potential for meeting current energy demands in a sustainable manner, process intensification and associated synergism can improve the resource utilization efficiency. Synergism of process intensification tools is important to increase energy efficiency, reduce chemical utilization and associated environmental impacts, and finally process economics. Among the many process intensification methods, this commentary provides a perspective on the essential role of MWs and US and their synergy in biofuel production. Individual, sequential, and simultaneous applications of MWs and US irradiations can be utilized for process intensification of various biofuels production and selective recovery of high value bioproducts. Process related barriers, namely mass and heat transfer limitations, can be eliminated by this synergism while improving the reaction efficiency and overall process economics significantly. In this article, a brief review focused on recent developments in MW and US mediated process intensification for biofuel synthesis and associated issues in their synergism followed by a discussion on current challenges and future prospective is presented

Role and Impact of Hydrograph Shape on Tidal Current-Induced Scour in Physical-Modelling Environments

For physical model tests, the time-varying characteristics of tidal currents are often simplified by a hydrograph following a shape of a unidirectional current or by resolving the tidal velocity signal into discrete steps of constant flow velocity. The influence of this generalization of the hydrograph’s shape on the scouring process in tidal currents has not yet been investigated systematically, further increasing the uncertainty in the prediction of scour depth and rate. Therefore, hydraulic model tests were carried out to investigate and quantify the influence of the hydrograph shape on the scouring processes under tidal currents. Several different hydrographs including those with continuously changing velocities, constant unidirectional currents, square-tide velocities and stepped velocity time series were analyzed. Results show that the scouring process in tidal currents is characterized by concurrent sediment backfilling and displacement which can only be reproduced by hydrographs that incorporate a varying flow direction. However, if only a correct representation of final scour depths is of interest, similar scour depths as in tidal currents might be achieved by a constant, unidirectional current, provided that a suitable flow velocity is selected. The effective flow work approach was found capable to identify such suitable hydraulic loads with reasonable practical accuracy

Volume-based assessment of erosion patterns around a hydrodynamic transparent offshore structure

The present article presents results of a laboratory study on the assessment of erosion patterns around a hydrodynamic transparent offshore foundation exposed to combined waves and currents. The model tests were conducted under irregular, long-crested waves in a scale of 1:30 in a wave-current basin. A terrestrial 3D laser scanner was used to acquire data of the sediment surface around the foundation structure. Tests have been conducted systematically varying from wave- to current-dominated conditions. Different volume analyzing methods are introduced, which can be related for any offshore or coastal structure to disclose physical processes in complex erosion patterns. Empirical formulations are proposed for the quantification of spatially eroded sediment volumes and scour depths in the near-field and vicinity of the structure. Findings from the present study agree well with in-situ data stemming from the field. Contrasting spatial erosion development between experimental and in-situ data determines a stable maximum of erosion intensity at a distance of 1.25 A, 1.25 times the structure’s footprint A, as well as a global scour extent of 2.1–2.7 A within the present study and about 2.7–2.8 A from the field. By this means, a structure-induced environmental footprint as a measure for erosion of sediment affecting marine habitat is quantified

Growth independent rhamnolipid production from glucose using the non-pathogenic Pseudomonas putida KT2440

<p>Abstract</p> <p>Background</p> <p>Rhamnolipids are potent biosurfactants with high potential for industrial applications. However, rhamnolipids are currently produced with the opportunistic pathogen <it>Pseudomonas aeruginosa </it>during growth on hydrophobic substrates such as plant oils. The heterologous production of rhamnolipids entails two essential advantages: Disconnecting the rhamnolipid biosynthesis from the complex quorum sensing regulation and the opportunity of avoiding pathogenic production strains, in particular <it>P. aeruginosa</it>. In addition, separation of rhamnolipids from fatty acids is difficult and hence costly.</p> <p>Results</p> <p>Here, the metabolic engineering of a rhamnolipid producing <it>Pseudomonas putida </it>KT2440, a strain certified as safety strain using glucose as carbon source to avoid cumbersome product purification, is reported. Notably, <it>P. putida </it>KT2440 features almost no changes in growth rate and lag-phase in the presence of high concentrations of rhamnolipids (> 90 g/L) in contrast to the industrially important bacteria <it>Bacillus subtilis, Corynebacterium glutamicum</it>, and <it>Escherichia coli. P. putida </it>KT2440 expressing the <it>rhlAB</it>-genes from <it>P. aeruginosa </it>PAO1 produces mono-rhamnolipids of <it>P. aeruginosa </it>PAO1 type (mainly C₁₀:C₁₀). The metabolic network was optimized in silico for rhamnolipid synthesis from glucose. In addition, a first genetic optimization, the removal of polyhydroxyalkanoate formation as competing pathway, was implemented. The final strain had production rates in the range of <it>P. aeruginosa </it>PAO1 at yields of about 0.15 g/g_glucosecorresponding to 32% of the theoretical optimum. What's more, rhamnolipid production was independent from biomass formation, a trait that can be exploited for high rhamnolipid production without high biomass formation.</p> <p>Conclusions</p> <p>A functional alternative to the pathogenic rhamnolipid producer <it>P. aeruginosa </it>was constructed and characterized. <it>P. putida </it>KT24C1 pVLT31_<it>rhlAB </it>featured the highest yield and titer reported from heterologous rhamnolipid producers with glucose as carbon source. Notably, rhamnolipid production was uncoupled from biomass formation, which allows optimal distribution of resources towards rhamnolipid synthesis. The results are discussed in the context of rational strain engineering by using the concepts of synthetic biology like chassis cells and orthogonality, thereby avoiding the complex regulatory programs of rhamnolipid production existing in the natural producer <it>P. aeruginosa</it>.</p

Observing the oceanic heat flux toward retreating outlet glaciers in NE-Greenland

Warming of subsurface water of Atlantic origin has been suggested to be a major driver of the ongoing retreat of marine terminating glaciers around the coast of Greenland. In recent years, also the outlet glaciers of the Northeast Greenland Ice Stream have undergone major changes leading to an increased mass flux from the ice sheet into the ocean. Both, the thinning of the 80-km long floating tongue of the 79 North Glacier and the collapse of the floating tongue of the adjacent Zachariæ Isstrøm have been attributed to increasing ocean temperatures. However, it has been unclear whether the bathymetry was sufficiently deep to allow warm Atlantic water to reach Zachariæ Isstrøm. Here we report on the first station-based bathymetric and oceanographic measurements carried out in summers 2016 and 2017 close to the calving front of Zachariæ Isstrøm. They reveal 1°C-warm waters of Atlantic origin in a layer between 300 to 600-m depth to be in direct contact with the calving front of the glacier. Also, 12-month long mooring based observations demonstrate Atlantic origin waters to flush the cavity beneath the 79 North Glacier causing high basal melt rates along the 80-km-long glacier base. Based on moored measurements further offshore on the Northeast Greenland continental shelf we discuss the processes that govern the oceanic heat transport toward both glaciers. A better understanding of these processes is relevant to distinguish short-term variability from long-term changes in the oceanic heat flux toward the glaciers

Development of a highly effective combination monoclonal antibody therapy against Herpes simplex virus.

BACKGROUND Infections with Herpes simplex virus (HSV)-1 or -2 usually present as mild chronic recurrent disease, however in rare cases can result in life-threatening conditions with a large spectrum of pathology. Monoclonal antibody therapy has great potential especially to treat infections with virus resistant to standard therapies. HDIT101, a humanized IgG targeting HSV-1/2 gB was previously investigated in phase 2 clinical trials. The aim of this study was to develop a next-generation therapy by combining different antiviral monoclonal antibodies. METHODS A lymph-node derived phage display library (LYNDAL) was screened against recombinant gB from Herpes simplex virus (HSV) -1 and HDIT102 scFv was selected for its binding characteristics using bio-layer interferometry. HDIT102 was further developed as fully human IgG and tested alone or in combination with HDIT101, a clinically tested humanized anti-HSV IgG, in vitro and in vivo. T-cell stimulating activities by antigen-presenting cells treated with IgG-HSV immune complexes were analyzed using primary human cells. To determine the epitopes, the cryo-EM structures of HDIT101 or HDIT102 Fab bound to HSV-1F as well as HSV-2G gB protein were solved at resolutions < 3.5 Å. RESULTS HDIT102 Fab showed strong binding to HSV-1F gB with Kd of 8.95 × 10-11 M and to HSV-2G gB with Kd of 3.29 × 10-11 M. Neutralization of cell-free virus and inhibition of cell-to-cell spread were comparable between HDIT101 and HDIT102. Both antibodies induced internalization of gB from the cell surface into acidic endosomes by binding distinct epitopes in domain I of gB and compete for binding. CryoEM analyses revealed the ability to form heterogenic immune complexes consisting of two HDIT102 and one HDIT101 Fab bound to one gB trimeric molecule. Both antibodies mediated antibody-dependent phagocytosis by antigen presenting cells which stimulated autologous T-cell activation. In vivo, the combination of HDIT101 and HDIT102 demonstrated synergistic effects on survival and clinical outcome in immunocompetent BALB/cOlaHsd mice. CONCLUSION This biochemical and immunological study showcases the potential of an effective combination therapy with two monoclonal anti-gB IgGs for the treatment of HSV-1/2 induced disease conditions

Sektionskonzept Meta(daten), Terminologien und Provenienz zur Einrichtung einer Sektion im Verein Nationale Forschungsdateninfrastruktur (NFDI) e.V

Die Sektion befasst sich mit den Themenbereichen (Meta)daten, Terminologien und Provenienz. Aufgabenfelder der Sektion umfassen organisatorische Aspekte (Kollaboration, Wissenstransfer), inhaltliche Aspekte (z.B. Modellierung/Ontologien) und infrastrukturelle Perspektiven (Entwicklung von Standards / Basisdiensten). Eine der wesentlichen Aufgaben der Sektion wird sein, die Arbeit der NFDI-Konsortien im Bereich (Meta)daten, Terminologien und Provenienz entlang der FAIR Kriterien wechselseitig sichtbar zu machen, zu harmonisieren und nachnutzbar zu machen. Hierbei wird die Sektion in enger Rückkopplung mit den Sektionen “Common Infrastructures” sowie “Ethical, Social and Legal Aspects” insbesondere die Themenbereiche Terminologien und Provenienz bearbeiten. (1) Im Themenbereich Metadaten und Forschungsdaten - im Folgenden kurz (Meta)daten - beschäftigt sich die Sektion mit Fragen zur (Meta-)daten-Harmonisierung, Auffindbarkeit von Daten, allgemeine Daten- und Metadaten-Standards mit Blick auf ein mögliches NFDI-Kernmetadatenformat sowie Formatumwandlungen und Persistent-Identifier-Systemen. (2) Im Themenbereich Terminologien beschäftigt sich die Sektion mit community- und disziplinenübergreifenden Definitionen von Top-Level Ontologien und Mappings von Ontologien sowie Best Practices zur Modellierung von Terminologien, Vokabularen und Ontologien sowie darauf aufbauenden Diensten zur Datenintegration (z.B. Terminology Service, Knowledge Graphs etc.). (3) Im Themenbereich Provenienz befasst sich die Sektion mit rechtlichen, technischen und kulturellen Aspekten des Entstehungskontextes von (Meta)daten (z.B. im Rahmen von Experimenten, Laborbüchern, Digitalisierungsprozessen etc.) und entwirft Vorschläge für einheitliche und nachvollziehbare Dokumentationsverfahren zur Beantwortung der Fragen nach dem was, wo, wann, wer, wie und warum der Datenerzeugung und Datenprozessierung. Hierbei entwickelt die Sektion Empfehlungen für die Abbildung der Provenienz in einem möglichen NFDI-Kernmetadatenformat