Wave Breaking Induced by Opposing Currents in Submerged Vegetation Canopies

Wave height attenuation in vegetation canopies is often all attributed to the drag force exerted by vegetation, whereas other potential dissipation process is often neglected. Previous studies without vegetation have found that opposing currents can induce wave breaking and greatly increase dissipation. It is not clear if similar process may...

Comparison of numerical predictions for early-age creep

Creep at early ages significantly affects the volumetric deformation of cementitious materials. Efficient modelling of early-age creep is a challenging task, mainly due to continuously evolving material properties (hydration) and other phenomena (e.g. autogenous shrinkage) taking place in parallel. Various methods were introduced during the past...

A 5×5 Microwave Permittivity Sensor Matrix in O.14-m CMOS

A 0.14-μ m CMOS 2-D permittivity imaging matrix prototype operating at microwave frequencies is presented. It comprises 25 permittivity-sensing pixels, each consisting of a sensing patch connected to a dedicated RF bridge. A trans-conduct-ance stage converts the imbalance voltage to a current signal, subsequently down-converted to an...

Short-term mudflat dynamics drive long-term cyclic salt marsh dynamics

Our study aims to enhance process understanding of the long-term (decadal and longer) cyclic marsh dynamics by identifying the mechanisms that translate large-scale physical forcing in the system into vegetation change, in particular (i) the initiation of lateral erosion on an expanding marsh, and (ii) the control of seedling establishment in...

Predicting long-term and short-term tidal flat morphodynamics using a dynamic equilibrium theory

Dynamic equilibrium theory is a fruitful concept, which we use to systematically explain the tidal flat morphodynamic response to tidal currents, wind waves, sediment supply, and other sedimentological drivers. This theory stems from a simple analytical model that derives the tide- or wave-dominated tidal flat morphology by assuming that...

Transition to turbulence in a qblique shock-wave/boundary-layer interaction at M=15

Direct numerical simulations are carried out for different forcing techniques to trigger transition during the interaction between an oblique shock-wave and a laminar boundary-layer at M = 1.5. Three forcing methods are used: a) forcing of oblique unstable modes, whose shape and behaviour are determined by the local linear stability theory, b)...

Windows of opportunity for salt marsh vegetation establishment on bare tidal flats: The importance of temporal and spatial variability in hydrodynamic forcing

Understanding the mechanisms limiting and facilitating salt marsh vegetation initial establishment is of widespread importance due to the many valuable services salt marsh ecosystems offer. Salt marsh dynamics have been investigated by many previous studies, but the mechanisms that enable or disable salt marsh initial establishment are still...

Tidal flat landscape formation and evolution

Tidal flat landscape formation and evolution are closely related to the biotic and abiotic processes that take place in the intertidal environments. Extensive studies have been carried out on the relevant agents such as hydrodynamics, sediment transport and the related ecosystem (vegetation and benthic communities) dynamics. However, the...

Coupled analysis of nonlinear sloshing and ship motions

Hydrodynamics of a 2D vessel including internal sloshing flows

Lysozyme and Penicillin Inhibit the Growth of Anaerobic Ammonium-Oxidizing Planctomycetes

Anaerobic ammonium-oxidizing (anammox) planctomycetes oxidize ammonium in the absence of molecular oxygen with nitrite as the electron acceptor. Although planctomycetes are generally assumed to lack peptidoglycan in their cell walls, recent genome data imply that the anammox bacteria have the genes necessary to synthesize peptidoglycan-like cell...

Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

Currently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentrations at mesophilic temperatures (25 to 40°C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater following carbon removal may lead to more-sustainable...

Drag coefficient of vegetation in flow modeling

Poster. The interaction between aquatic plants and hydrodynamic force and its implication on the long-term landscape development have received intention from ecology, geology and hydraulic engineering.

Rapid and Simple Cryopreservation of Anaerobic Ammonium-Oxidizing Bacteria

A quick and simple protocol for long-term cryopreservation of anaerobic ammonium-oxidizing bacteria (anammox bacteria) was developed. After 29 weeks of preservation at ?80°C, activity recovery for all tested cultures under at least one of the applied sets of preservation conditions was observed. Growth recovery was also demonstrated for a single...

Interaction between hydrodynamics and salt marsh dynamics: An example from Jiangsu coast

Salt marshes are distributed along more than 400 km of the Jiangsu coast in Eastern China, which are regarded as important habitats and serve as coastal protection as well. Previous research has proven that salt-marsh vegetation can reduce current velocity and dampen waves by its stems and leaves. Reversely, hydrodynamic forces also have a...

Receiver Windowing Design for Narrowband Interference Mitigation in MB-OFDM UWB System

In 2005, the WiMedia Alliance working with the European Computer Manufacturers Association (ECMA) announced the establishment of the WiMedia MB-OFDM (Multiband Orthogonal Frequency Division Multiplexing) UWB radio platform as their global UWB standard. It was also chosen as the physical layer (PHY) of high data rate wireless specifications for...

The influence of fresnel number and geometric parameters on the diffracted field of planar lamina