droplet infiltration
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Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 791
Author(s):  
Zhongwei Liang ◽  
Xiaochu Liu ◽  
Tao Zou ◽  
Jinrui Xiao

As the high productive efficiency of sprinkler irrigation is largely based on balanced soil moisture distribution, it is essential to study the exact effectiveness of water droplet infiltration, which provides a theoretical basis for rationally scheduling the circulation efficiency of groundwater in agricultural irrigation performance. This research carried out adaptive prediction of the droplet infiltration effectiveness of sprinkler irrigation by using a novel approach of a regularized sparse autoencoder–adaptive network-based fuzzy inference system (RSAE–ANFIS), for the purpose of quantifying actual water droplet infiltration and effectiveness results of precision irrigation in various environmental conditions. The intelligent prediction experiment we implemented could be phased as: the demonstration of governing equations of droplet infiltration for sprinkler irrigation modeling; the measurement and computation of probability densities in water droplet infiltration; innovative establishment and working analysis of RSAE–ANFIS; and the adaptive prediction of infiltration effectiveness indexes, such as average soil moisture depth increment (θ, mm), irrigation infiltration efficiency (ea, %), irrigation turn duration efficiency (et, mm/min), and the uniformity coefficient of soil moisture infiltration (Cu, %), which were implemented to provide a comprehensive illustration for the effective scheduling of sprinkler irrigation. Result comparisons indicated that when jetting pressure (Pw) was 255.2 kPa, the impinge angle (Wa) was 42.5°, the water flow rate (Fa) was 0.67 kg/min, and continuous irrigation time (Tc) was 32.4 min (error tolerance = ±5%, the same as follows), thereby an optimum and stable effectiveness quality of sprinkler irrigation could be achieved, whereas average soil moisture depth increment (θ) was 57.6 mm, irrigation infiltration efficiency (ea) was 62.5%, irrigation turn duration efficiency (et) was 34.5 mm/min, and the uniformity coefficient of soil moisture infiltration (Cu) was 53.6%, accordingly. It could be concluded that the proposed approach of the regularized sparse autoencoder–adaptive network-based fuzzy inference system has outstanding predictive capability and possesses much better working superiority for infiltration effectiveness in accuracy and efficiency; meanwhile, a high agreement between the adaptive predicted and actual measured values of infiltration effectiveness could be obtained. This novel intelligent prediction system has been promoted constructively to improve the quality uniformity of sprinkler irrigation and, consequently, to facilitate the productive management of sprinkler irrigated agriculture.



2021 ◽  
Author(s):  
Thuc Nguyen ◽  
Gilboa Arye

<p>Surfactants have been long used to aid water infiltration into hydrophobic soils since it can reduce the surface tension of water and consequently, the contact angle (CA) form at the solid-liquid-air interface. The degree of soil hydrophobicity is commonly engaged with direct or indirect measurements of the apparent initial advancing CA which is not necessarily correlated with infiltration characteristics of aqueous surfactant solutions. The main objective of this study was to quantify the dynamics of surfactant drop penetration into hydrophobic soils. Three surfactants were examined: anionic (SDS), cationic (CTAB), and nonionic (TX100) at aqueous concentrations of 0.4, 0.8, 1, and 2 C/CMC (where C is the bulk concentration and CMC is critical micelle concentration). Sand with the particle size distribution of 100-210, 425-500, and 600-700 μm was hydrophobized using Leonardite (IHSS). Each run was initiated by placing a 30 μL droplet on the soil surface that was packed into quartz cuvette (2.5×2.5×4 cm). The droplet infiltration dynamics were monitored by an optical goniometer (OCA 20, DataPhysics, Germany), specifically, the drop height, drop base diameter, and CA as a function of time. Notable differences between droplet infiltration characteristics of the three surfactants could be observed. For a given particle fraction, the TX100 and SDS, at concentrations above and below the CMC, the CA and drop height decreased while the drop base diameter increased, suggesting that spreading took place during infiltration. For the CTAB, a significant lag-phase could be observed for all quantities, ranging from 100 to 1000. Following this phase, the drop height and CA showed a relatively gradual decrease while the base diameter exhibited minor changes, suggesting minor changes in solution spreading on the soil surface. Additional observation and interpretation on infiltration characteristics of aqueous surfactants solution will be presented and their implications for enhanced infiltration rate in hydrophobic soils will be discussed.    </p>



Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 251 ◽  
Author(s):  
Wen-Wan Chao ◽  
Shu-Ju Chen ◽  
Hui-Chen Peng ◽  
Jiunn-Wang Liao ◽  
Su-Tze Chou

(1) Background: Graptopetalum paraguayense E. Walther is a traditional Chinese herbal medicine. In our previous study, 50% ethanolic G. paraguayense extracts (GE50) demonstrated good antioxidant activity. (2) Methods: To investigate the hepatoprotective effects of GE50 on ethanol and carbon tetrachloride (CCl4) co-induced hepatic damage in rats, Sprague–Dawley rats were randomly divided into five groups (Control group; GE50 group, 0.25 g/100 g BW; EC group: Ethanol + CCl4, 1.25 mL 50% ethanol and 0.1 mL 20% CCl4/100 g BW; EC + GE50 group: Ethanol + CCl4 + GE50; EC + silymarin group: ethanol + CCl4 + silymarin, 20 mg/100 g BW) for six consecutive weeks. (3) Results: Compared with the control group, EC group significantly elevated the serum aspartate aminotransferase (AST), alanine aminitransferase (ALT), and lactate dehydrogenase (LDH). However, GE50 or silymarin treatment effectively reversed these changes. GE50 had a significant protective effect against ethanol + CCl4 induced lipid peroxidation and increased the levels of glutathione (GSH), vitamin C, E, total antioxidant status (TAS), and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and glutathione S-transferases (GST). Furthermore, in EC focal group, slight fat droplet infiltration was observed in the livers, while in the GE50 or silymarin treatment groups, decreased fat droplet infiltration. HPLC phytochemical profile of GE50 revealed the presence of gallic acid, flavone, genistin, daidzin, and quercetin. (4) Conclusions: The hepatoprotective activity of GE50 is proposed to occur through the synergic effects of its chemical component, namely, gallic acid, flavone, genistin, daidzin, and quercetin. Hence, G. paraguayense can be used as a complementary and alternative therapy in the prevention of alcohol + CCl4-induced liver injury.



2018 ◽  
Vol 32 (23) ◽  
pp. 1850272 ◽  
Author(s):  
Yuanyuan Wang ◽  
Pengfei Jia ◽  
Weidong Yang ◽  
Kai Peng ◽  
Sixiang Zhang

The purpose of this paper is to lessen the deviation of printing and to predict the nucleus size of binder droplet infiltration in three-dimensional printing (3DP) technology. The industrial CT is used to scan powders and the parameters of materials are calculated. A spherical model, which is based on the data from industrial CT scanning, predicts the nucleus size. The radius of the sphere is equal to the average radius of the sand particles. The spreading radius of binder droplet on the material is obtained by using the experimental method, and then the nucleus size is calculated by the equations. In order to do research on the process of droplet infiltration more intuitively, we analyze the effects of contact angle, porosity and drop height on the infiltration by using the software Comsol in the simulation. To verify the results of the simulation, the processes of infiltration are recorded by the high-speed digital video camera, and the nucleus size is observed by electron microscope. The study is important to conduct the infiltration experiments and provides a theoretical basis for optimization of process parameters in practical application.



2016 ◽  
Vol 11 (4) ◽  
pp. 155892501601100 ◽  
Author(s):  
Wei Liu ◽  
Fujun Xu ◽  
Nianhua Zhu ◽  
Shuang Wang

Carbon nano tube (CNT) yarn is an axially aligned CNT assembly. It has great potential many applications. In this study, the mechanical and electrical properties of the aerogel-spun CNT yarns and CNT/Polydimethylsiloxane (PDMS) composite yarns were investigated. The CNT/PDMS yarn was fabricated by droplet infiltration of PDMS solution into the aerogel-spun CNT yarn. The mechanical properties of the CNT/PDMS yarns were significantly improved with an average strength of 837.29 MPa and modulus of 3.66 GPa, over 100% improvement compared to the original CNT yarns. The electrical conductivity of the CNT/PDMS yarn increased from 1636 S/cm to 3555 S/cm. The electromechanical properties of CNT/PDMS yarns demonstrated that such CNT yarn could be suitable for strain sensors.



2016 ◽  
Vol 64 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Miroslav Fér ◽  
Martin Leue ◽  
Radka Kodešová ◽  
Horst H. Gerke ◽  
Ruth H. Ellerbrock

Abstract The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at−b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.







2011 ◽  
Vol 45 (22) ◽  
pp. 9666-9670 ◽  
Author(s):  
Christopher A. E. Hamlett ◽  
Neil J. Shirtcliffe ◽  
Glen McHale ◽  
Sujung Ahn ◽  
Robert Bryant ◽  
...  


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