Modelling Wetting and Drying Processes in Hydraulic Models

On carbonizing phenolic resins, the development of porous structure takes place which influences the transport properties of carbonized materials. To give a true picture of this effect, specimens in the shape of plates were prepared and carbonized at various temperatures. The carbonizates obtained were studied by adsorption methods, electron microscopy, and mercury porosimetry. Diffusivities were evaluated in terms of measuring the kinetics of wetting and drying. It was found out that the porous structure of specimens in different stages of carbonization is formed mostly by micropores whose volumes were within 0.06 to 0.22 cm3/g. The maximum micropore volume is reached at the temperature of 750 °C. The dependence of diffusivity on the carbonization temperature is nearly constant at first, begins to increase in the vicinity of 400 °C, and at 600 °C attains its maximum. The experimental results reached are in agreement with the conception of the development and gradual closing of the microporous structure in the course of carbonization. The dependence of diffusivity on temperature can be expressed by the Arrhenius equation. In this connection, two possible models of mass transport were discussed.

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A Conflict between Traditional Flood Measures and Maintaining River Ecosystems? A Case Study Based upon the River Lærdal, Norway

Water ◽

10.3390/w13141884 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1884

Author(s):

Ana Juárez ◽

Knut Alfredsen ◽

Morten Stickler ◽

Ana Adeva-Bustos ◽

Rodrigo Suárez ◽

...

Keyword(s):

Remote Sensing Data ◽

Freshwater Ecosystems ◽

River Channel ◽

Flood Mitigation ◽

Mitigation Measures ◽

Flood Events ◽

Protection Measures ◽

River Ecosystems ◽

Hydraulic Models

Floods are among the most damaging of natural disasters, and flood events are expected to increase in magnitude and frequency with the effects of climate change and changes in land use. As a consequence, much focus has been placed on the engineering of structural flood mitigation measures in rivers. Traditional flood protection measures, such as levees and dredging of the river channel, threaten floodplains and river ecosystems, but during the last decade, sustainable reconciliation of freshwater ecosystems has increased. However, we still find many areas where these traditional measures are proposed, and it is challenging to find tools for evaluation of different measures and quantification of the possible impacts. In this paper, we focus on the river Lærdal in Norway to (i) present the dilemma between traditional flood measures and maintaining river ecosystems and (ii) quantify the efficiency and impact of different solutions based on 2D hydraulic models, remote sensing data, economics, and landscape metrics. Our results show that flood measures may be in serious conflict with environmental protection and legislation to preserve biodiversity and key nature types.

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X‐ray tomography analysis of soil biopores structure under wetting and drying cycles

European Journal of Soil Science ◽

10.1111/ejss.13119 ◽

2021 ◽

Author(s):

Sougueh Cheik ◽

Pascal Jouquet ◽

Jean‐Luc Maeght ◽

Yvan Capowiez ◽

T.M. Tran ◽

...

Keyword(s):

Wetting And Drying ◽

X Ray ◽

Wetting And Drying Cycles ◽

Tomography Analysis

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Moisture performance of interior insulated brick wall segments subjected to wetting and drying – A laboratory investigation

Building and Environment ◽

10.1016/j.buildenv.2020.107488 ◽

2020 ◽

pp. 107488

Author(s):

Jon Ivar Knarud ◽

Stig Geving ◽

Tore Kvande

Keyword(s):

Laboratory Investigation ◽

Brick Wall ◽

Wetting And Drying ◽

Moisture Performance

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Differential effects of wetting and drying on soil CO2 concentration and flux in near-surface vs. deep soil layers

Biogeochemistry ◽

10.1007/s10533-020-00658-7 ◽

2020 ◽

Vol 148 (3) ◽

pp. 255-269 ◽

Cited By ~ 2

Author(s):

Kyungjin Min ◽

Asmeret Asefaw Berhe ◽

Chau Minh Khoi ◽

Hella van Asperen ◽

Jeroen Gillabel ◽

...

Keyword(s):

Co2 Concentration ◽

Soil Co2 ◽

Deep Soil ◽

Wetting And Drying ◽

Near Surface ◽

Soil Layers ◽

Differential Effects ◽

Soil Co2 Concentration

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Impact of Organic Amendment with Alternate Wetting and Drying Irrigation on Rice Yield, Water Use Efficiency and Physicochemical Properties of Soil

Agronomy ◽

10.3390/agronomy11081529 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1529

Author(s):

Ahmad Numery Ashfaqul Haque ◽

Md. Kamal Uddin ◽

Muhammad Firdaus Sulaiman ◽

Adibah Mohd Amin ◽

Mahmud Hossain ◽

...

Keyword(s):

Physicochemical Properties ◽

Water Use Efficiency ◽

Water Use ◽

Organic Amendment ◽

Rice Yield ◽

Organic Amendments ◽

Irrigation Regime ◽

Wetting And Drying ◽

Use Efficiency ◽

Properties Of Soil

A pot experiment was executed to investigate the impact of biochar and compost with water-saving irrigation on the rice yield, water use efficiency, and physicochemical properties of soil. Two irrigation regimes—namely alternate wetting and drying (AWD) and continuous flooding (CF)—and four types of organic amendments (OA)—namely rice husk biochar (RHB), oil palm empty fruit bunch biochar (EFBB), compost and a control—were applied to evaluate their effects. Under the AWD irrigation regime, the maximum grain was produced by RHB (241.12 g), whereas under the same organic amendments, both AWD and CF produced a similar grain yield. Under the same organic amendment, a significantly higher water use efficiency (WUE) was observed from the AWD irrigation with RHB (6.30 g L−1) and EFBB (5.80 g L−1). Within the same irrigation regime, soil pH, cation exchange capacity, total carbon, total nitrogen and available phosphorus were enhanced due to the incorporation of biochar and compost, while higher soil exchangeable potassium was observed under CF irrigation for all treatments. RHB and EFBB significantly reduced the soil bulk density (up to 20.70%) and increased porosity (up to 16.70%) under both irrigation regimes. The results imply that the use of biochar with AWD irrigation could enhance the nutrient uptake and physicochemical properties of soil and allow rice to produce a greater yield with less water consumption.

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