scholarly journals Attachment strength of seed mucilage prevents seed dislodgement in high surface flow: a mechanistic investigation

2021 ◽  
Author(s):  
Vincent S. Pan ◽  
Cecilia Girvin ◽  
Eric F. LoPresti
Keyword(s):  
Water Flow ◽  
Mechanistic Model ◽  
High Surface ◽  
Surface Flow ◽  
Primary Role ◽  
Standard Deviation Increase ◽  
Fluid Resistance ◽  
Mechanistic Investigation ◽  
Attachment Strength ◽  
Seed Mucilage

Seed mucilage is a common and highly diverse trait shared among thousands of angiosperms. While long recognized that mucilage allows seeds to anchor to substrates (antitelechory), we still lack a mechanistic understanding of this process. We propose a mechanistic model of how mucilage affects substrate anchorage and fluid resistance, ultimately contributing to antitelechory. To test this model, we subjected mucilaginous seeds of 52 species, varying in eight measured seed traits, to a week of continuous water flow at a range of erosion potentials. Supporting our model, mucilage mass increased both dry and wet attachment strength, which explained time to erosion well. A standard deviation increase in log mucilage mass increased seed time to dislodgement by 280 times. Fluid resistance was largely dependent on speed of water flow and the seed's modified drag coefficient, but not the quality of the seed or seed mucilage. Neither mucilage expansion speed nor mucilage decay rate explained dislodgement potential well. Our results suggest that the high substrate anchorage strength is the primary role of mucilage in fostering seed establishment in highly erosive environments. In contrast, other seed and mucilage trait differences among species are of lesser importance to antitelechory.

scholarly journals CFD Code Validation against Stratified Air-Water Flow Experimental Data

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
F. Terzuoli ◽  
M. C. Galassi ◽  
D. Mazzini ◽  
F. D'Auria
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Water Flow ◽  
Nuclear Reactor ◽  
Cold Water ◽  
Three Dimensional ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Two Phase ◽  
Code Validation

Pressurized thermal shock (PTS) modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV) lifetime is the cold water emergency core cooling (ECC) injection into the cold leg during a loss of coolant accident (LOCA). Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM) Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs) code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX), and a research code (NEPTUNE CFD). The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling.

scholarly journals System Dynamic Model for Lake’s Water Flow: A Case Of Situ Binong, Cikarang, West Java, Indonesia

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Muchammad Chusnan Aprianto
Keyword(s):  
Water Resources ◽  
Dynamic System ◽  
Water Flow ◽  
Natural Water ◽  
Surface Flow ◽  
System Model ◽  
Domestic Waste ◽  
The Relationship ◽  
Lake Size

This study aims to develop a dynamic system model that describes the relationship ofwater, socio-economic, and water resources (lake size) sub-systems in Situ Binong. In addition,this study also aims to make predictions of water resources conditions (lake size) Situ Binong forthe next 5 years. The model is prepared using a dynamic system approach. The Situ Binong waterflow model is available water resources consisting of 3 sub-systems namely natural water flowsub-systems, socio-economic, and water resources Situ Binong. The result of the research showsthat the requirement of Situ Binong water resources every year is increasing so that the volume ofSitu Binong is decreasing. In addition, the volume of water resources Situ Binong influenced bysupply and demand. Supply comes from domestic waste and natural water flow such asprecipitation, infiltration and surface flow. While demand comes from WTP intake, irrigation, andevaporation.

Surface and volume flow of single gases and of binary gas mixtures in a microporous carbon membrane

1966 ◽  
Vol 290 (1423) ◽  
pp. 477-489 ◽  
Keyword(s):  
Permeability Coefficient ◽  
Competitive Adsorption ◽  
Diffusion Mechanism ◽  
High Surface ◽  
High Surface Area ◽  
Surface Flow ◽  
Volume Flow ◽  
Microporous Carbon ◽  
Carbon Membrane ◽  
Surface Hopping

Surface and volume flow have been studied in a microporous carbon membrane of high surface area for He, Ar, Na, Kr and CO 2 and for the mixtures Kr + N 2 and CO 2 + Kr. Although the adsorption extended beyond the range in which Henry’s law was valid, the permeability coefficient, K, remained independent of amount sorbed and isotherm curvature. For a given gas the permeability coefficient was also identical for the pure gas and for the gas in binary mixtures in which competitive adsorption was occurring. These results indicate that, in the range investigated, surface flow occurred by a random walk diffusion mechanism (surface hopping), rather than by a viscous flow mechanism . The products K√M ( M denoting molecular weight) show smooth correlations with parameters determining the adsorbability of the flowing gases.

scholarly journals Unveiling a Recycling-Sourced Mineral-Biocellulose Fibre Composite for Use in Combustion-Generated NOx Mitigation Forming Plant Nutrient: Meeting Sustainability Development Goals in the Circular Economy

2020 ◽  
Vol 10 (11) ◽  
pp. 3927
Author(s):  
Patrick Gane ◽  
Katarina Dimić-Mišić ◽  
Nemanja Barać ◽  
Monireh Imani ◽  
Djordje Janaćković ◽  
...  
Keyword(s):  
Circular Economy ◽  
Negative Impact ◽  
Fibre Composite ◽  
High Surface ◽  
High Surface Area ◽  
Calcium Nitrate ◽  
Surface Flow ◽  
Test Bed ◽  
Cellulose Fibres ◽  
Run Off

NOx is unavoidably emitted during combustion in air at high temperature and/or pressure, which, if exceeding recommended levels, has a negative impact on the population. The authors found that when moist, limestone (CaCO3) readily sorbs NO2 to form calcium nitrate, which provides the basis for developing a surface flow filter. The substrate was made from “over-recycled” cellulose fibres such as newsprint, magazines, or packaging fibre, which are too weak to be used in further recycling. The substrate was specially-coated with fine-ground calcium carbonate and micro-nano-fibrillated cellulose, which was used as a binder and essential humectant to avoid formation of a stagnant air layer. Pre-oxidation countered the action of denitrification bacteria colonising the cellulose substrate. The by-product CO2 produced in situ during carbonate to nitrate conversion was adsorbed by perlite, which is an inert high surface-area additive. After use, the nitrate-rich CaCO3-cellulose-based filter was proposed to be mulched into a run-off resistant soil fertiliser and micronutrient suitable, e.g., for renewable forestry within the circular economy. Belgrade, Serbia, which is a highly polluted city, was used as a laboratory test bed, and NO2 was successfully removed from an inlet of city air. A construct of street-side self-draughting or municipal/commercial transport vehicle-exterior motion-draught filter boxes is discussed.

scholarly journals Капиллярно-волновой варп-двигатель

2021 ◽  
Vol 47 (22) ◽  
pp. 13
Author(s):  
В.А. Александров
Keyword(s):  
Fluid Flow ◽  
Surface Water ◽  
Water Flow ◽  
Liquid Surface ◽  
Capillary Wave ◽  
Local Deformation ◽  
Surface Flow ◽  
Surface Water Flow

The generation of surface water flow in channels with sources and resonators of capillary oscillations is detected and investigated. Moving devices with a capillary-wave accelerator of the surface fluid flow are demonstrated. The surface flow of liquid in the channel is generated due to the local deformation of the liquid surface by capillary vibrations and the formation of an excess liquid surface on average near the source and the transport of this surface by waves.

scholarly journals Assessment of Wind and Vegetation Interactions in Constructed Wetlands

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1937
Author(s):  
Mohamed Moustafa ◽  
Naiming Wang
Keyword(s):  
Wind Speed ◽  
Nutrient Uptake ◽  
Water Flow ◽  
Meteorological Data ◽  
Biotic Interactions ◽  
Open Water ◽  
Surface Flow ◽  
Wet Season ◽  
Hydraulic Residence Time ◽  
Measured Velocity

Meteorological data from vegetated and un-vegetated wetlands during wet and dry seasons, were collected and analyzed to evaluate the role of wind and vegetation on wetlands’ hydrology. Wind speed diminished by as much as 40%, accompanied by a measurable change in wind directions in the vegetated compared to the open water site. Wind speed and direction means were significantly different (p < 0.001 and <0.01), for vegetated and non-vegetated wetland, respectively. Cattails (Typha sp.) and open water estimates of wind drag coefficients using the log wind profile, were 0.016 and 0.009 for dry season, and 0.012 and 0.005 for wet season, respectively. Wind set up near the wetland outlet was more pronounced at shallow water depth (<20 cm). Measured velocity profile during inflow discharge event with a wind speed of 0.53 ms−1, showed two-layer flows; wind-generated surface water flow opposite to a sub-surface inflow. This opposing surface flow increases hydraulic residence time and improve nutrient uptake. Conversely, wind-generated flows aligned with inflow discharges, accelerates water flow towards the outlet, reduce the duration of water-biotic interactions, and decrease nutrient uptake.

scholarly journals Evaluation of the HEC-HMS model for the hydrological simulation of a paramo basin

DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 338-344
Author(s):  
Luis Manuel Timbe Castro ◽  
Patricio Javier Crespo Sánchez ◽  
Juan José Cabrera-Balarezo
Keyword(s):  
Soil Moisture ◽  
Water Flow ◽  
Soil Surface ◽  
Surface Flow ◽  
Rainfall Distribution ◽  
Hydrological Simulation ◽  
Soil Moisture Accounting ◽  
Calibration And Validation ◽  
Daily Data ◽  
Monteith Equation

In this study, the performance of the HEC-HMS model was evaluated for the simulation of rain-runoff processes in a paramo basin of approximately 21. 8 km2, south of Ecuador. The calibration and validation comprises the period of July-2013 to June-2016 with daily data. The Soil Moisture Accounting (SMA) method was used to compute the water flow in the soil. For the rainfall distribution, the Thiessen method was used, while the Evapotranspiration was calculated with the Penman-Monteith equation. The results revealed that (1) 83% of the water infiltrates the soil while only 17% is retained in plants and the soil surface, (2) the water is retained for approximately 42 days before reaching the river and (3) that more than 60% of the flow corresponds to sub-surface flow.

Attachment strength of an adhesive nuisance mussel,limnoperna fortunei,against water flow

Biofouling ◽  
2001 ◽  
Vol 17 (4) ◽  
pp. 263-274 ◽  
Author(s):  
Keiji Nagaya ◽  
Yoshihiko Matsui ◽  
Hironobu Ohira ◽  
Akira Yuasa ◽  
Hiroyuki Yamamoto ◽  
...  
Keyword(s):  
Water Flow ◽  
Limnoperna Fortunei ◽  
Attachment Strength

scholarly journals Analysis of hull resistance of pushed barges in shallow water

2007 ◽  
Vol 14 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Tomasz Tabaczek ◽  
Jan Kulczyk ◽  
Maciej Zawiślak
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Viscous Liquid ◽  
Water Flow ◽  
Computer Software ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Numerical Calculations

Analysis of hull resistance of pushed barges in shallow water These authors performed a set of numerical calculations of water flow around pushed barges differing to each other by bow forms. The calculations were executed by means of FLUENT computer software. Turbulent free-surface flow of viscous liquid was considered. In this paper the calculated values of barge hull resistance split into bow, cylindrical and stern part components, have been compared and presented.

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