Long-Term Strength of Porous Geomaterials by a Micromechanical Model considering Alternate Wetting and Drying Condition

This study is devoted to determining the long-term strength of porous geomaterials under alternate wetting and drying condition by statical shakedown analysis. In the framework of micromechanics of porous materials, Gurson’s hollow sphere model with Drucker-Prager solid matrix is adopted as the representative volume element. The effects of alternate wetting and drying are considered as variable water pressure imposed on the inner boundary surface of the unit cell. The cyclic responses are separated as a pure hydrostatic part under compressive/tensive loads and an additional deviatoric part to capture shear effects. The reduction of the long-term strength due to inner water pressure is observed by the illustration of obtained macroscopic criteria with respect to various load parameters. In addition, the accuracy of the analytical solution is also verified by comparing to the results of FEM-based step-by-step computations.

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Failure process of acrylic polyurethane coating under alternate wetting and drying condition

Journal of Applied Polymer Science ◽

10.1002/app.41989 ◽

2015 ◽

Vol 132 (20) ◽

pp. n/a-n/a ◽

Cited By ~ 4

Author(s):

Yu Zuo ◽

Liang Zhang ◽

Xuhui Zhao ◽

Yuming Tang ◽

Xiaofeng Zhang

Keyword(s):

Failure Process ◽

Polyurethane Coating ◽

Wetting And Drying ◽

Alternate Wetting And Drying ◽

Drying Condition ◽

Acrylic Polyurethane

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Root Traits Enhancing Rice Grain Yield under Alternate Wetting and Drying Condition

Frontiers in Plant Science ◽

10.3389/fpls.2017.01879 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 15

Author(s):

Nitika Sandhu ◽

Sushil R. Subedi ◽

Ram B. Yadaw ◽

Bedanand Chaudhary ◽

Hari Prasai ◽

...

Keyword(s):

Grain Yield ◽

Root Traits ◽

Rice Grain ◽

Wetting And Drying ◽

Alternate Wetting And Drying ◽

Drying Condition

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Experimental Research on Creep Laws of High-Water Material under Real Pressure Water Environment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.705.350 ◽

2016 ◽

Vol 705 ◽

pp. 350-354

Author(s):

Hui Xie ◽

Ying Chen

Keyword(s):

Experimental Research ◽

Carrying Capacity ◽

Water Pressure ◽

Water Environment ◽

High Water ◽

Term Strength ◽

Steady Creep ◽

Creep Tests ◽

Pressure Water

High-water material is a kind of new inorganic nonmetal material which mainly used in coal mine goaf filling. In order to simulate the real stress conditions of this material in goaf filling, the creep tests of high-water material in real pressure water environment were conducted and the creep laws were also researched. The results showed that water environment was conductive to maintaining and developing the strength of high-water material, and pressure water environment can improve the carrying capacity and long-term strength of high-water material. The deformation of steady creep period decreased while water pressure increased. And strain increasing caused by axial compression was less than strain increasing caused by water pressure. The time needed from starting to steady creep period was longer when water pressure was bigger.

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Arsenic Accumulation in Rice Grain as Influenced by Water Management: Human Health Risk Assessment

Agronomy ◽

10.3390/agronomy11091741 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1741

Author(s):

Israt Jahan Harine ◽

Mohammad Rafiqul Islam ◽

Mahmud Hossain ◽

Hasina Afroz ◽

Rounok Jahan ◽

...

Keyword(s):

Water Management ◽

Health Risk ◽

Management Practices ◽

Human Health Risk ◽

Rice Grain ◽

Wetting And Drying ◽

Straw Yield ◽

Alternate Wetting And Drying ◽

Drying Condition ◽

1000 Grain Weight

Rice is a staple food for humans and a key source of soil arsenic (As) transfer to the human food chain. As a result, it is critical to develop ways for reducing As accumulation in rice. A pot experiment with seven different water management practices was done to examine the impacts of water management on rice (cv. BRRI dhan28) growth, yield, and As accumulation in rice grain. Any health risk due to As accumulation in rice grain was also determined. The soil used in the experiment was artificially contaminated with As and the source of As was sodium arsenate (Na2HAsO4 7H2O). Water management practices affect different plant growth and yield parameters including filled grains per panicle, unfilled grains per panicle, 1000-grain weight, grain yield and straw yield of rice. The number of filled grains per panicle and 1000-grain weight were found to be at their highest in the T7 (alternate wetting and drying) condition, whereas the number of unfilled grains per panicle was at its lowest in the same treatment. The T7 also demonstrated the highest grain yield (21.08 g/pot) and straw yield (22.02 g/pot), whereas the lowest values were noted in T1 (flooding throughout the growth period). The highest As concentration in rice grain (0.52 mg kg−1) was found in T1 and the lowest As concentration in grain (0.27 mg kg−1) was found in T7. Estimation of the human health risk revealed that the non-carcinogenic risks (HQ > 1) and carcinogenic risks (CR > 1.0 × 10−4) were greatly affected by different water regimes. The rice plant grown under alternate wetting and drying condition (T7) showed the lowest health risks compared to other water management practices. Thus, alternate wetting and drying conditions are a good water management strategy for increasing rice output while reducing arsenic buildup in rice grain.

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Dimensioning of Wide-Area Alternate Wetting and Drying (AWD) System for IoT-Based Automation

Sensors ◽

10.3390/s21186040 ◽

2021 ◽

Vol 21 (18) ◽

pp. 6040

Author(s):

Mushran Siddiqui ◽

Farhana Akther ◽

Gazi M. E. Rahman ◽

Mohammad Mamun Elahi ◽

Raqibul Mostafa ◽

...

Keyword(s):

Irrigation System ◽

Water Pressure ◽

Rice Production ◽

Wide Area ◽

External Control ◽

Physiological Data ◽

Small Scale ◽

Wetting And Drying ◽

Irrigated Rice ◽

Alternate Wetting And Drying

Water, one of the most valuable resources, is underutilized in irrigated rice production. The yield of rice, a staple food across the world, is highly dependent on having proper irrigation systems. Alternate wetting and drying (AWD) is an effective irrigation method mainly used for irrigated rice production. However, unattended, manual, small-scale, and discrete implementations cannot achieve the maximum benefit of AWD. Automation of large-scale (over 1000 acres) implementation of AWD can be carried out using wide-area wireless sensor network (WSN). An automated AWD system requires three different WSNs: one for water level and environmental monitoring, one for monitoring of the irrigation system, and another for controlling the irrigation system. Integration of these three different WSNs requires proper dimensioning of the AWD edge elements (sensor and actuator nodes) to reduce the deployment cost and make it scalable. Besides field-level monitoring, the integration of external control parameters, such as real-time weather forecasts, plant physiological data, and input from farmers, can further enhance the performance of the automated AWD system. Internet of Things (IoT) can be used to interface the WSNs with external data sources. This research focuses on the dimensioning of the AWD system for the multilayer WSN integration and the required algorithms for the closed loop control of the irrigation system using IoT. Implementation of the AWD for 25,000 acres is shown as a possible use case. Plastic pipes are proposed as the means to transport and control proper distribution of water in the field, which significantly helps to reduce conveyance loss. This system utilizes 250 pumps, grouped into 10 clusters, to ensure equal water distribution amongst the users (field owners) in the wide area. The proposed automation algorithm handles the complexity of maintaining proper water pressure throughout the pipe network, scheduling the pump, and controlling the water outlets. Mathematical models are presented for proper dimensioning of the AWD. A low-power and long-range sensor node is developed due to the lack of cellular data coverage in rural areas, and its functionality is tested using an IoT platform for small-scale field trials.

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