Compressive properties and least limiting water range of plough layer and plough pan in sugarcane fields

Author(s):  
Renato P. Lima ◽  
Mário M. Rolim ◽  
Daniel da Dantas ◽  
Anderson R. Silva ◽  
Edwardo A. S. Mendonça
2021 ◽  
pp. 003072702110018
Author(s):  
Benhui Wei ◽  
Suoyi Han ◽  
Guohao He

Smash-ridging cultivation is an efficient farming method that was recently developed in China. The technique involves vertically cutting by using a spiral drill, causing the soil to ‘suspend’ as ridges, thereby breaking through the traditional plough pan, and thickening the plough layer up to 30–50 cm. Smash-ridging cultivation has effectively improved soil quality and has increased the water and nutrient retention capacity. Loose soil enables the plant’s root system to optimally develop and more efficiently absorb nutrients. This facilitates the growth of the above ground parts of plant, leading to a significant increase in crop yield. This method has been successfully applied on 40 crops and tested in 26 provinces. The yield increase within a single season ranges from 10.0% to 54.8%. This technique may have a positive and extensive impact on food safety and agricultural production in China and the rest of the world.


2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.


2020 ◽  
Vol 35 (23-24) ◽  
pp. 3157-3169
Author(s):  
Qingyuan Xu ◽  
Shuguang Li ◽  
Runsheng Hu ◽  
Mengmeng Liu ◽  
Dong Wang ◽  
...  

Abstract


Author(s):  
V. А. Shevchenko ◽  
A. V. Nefedov ◽  
A. V. Ilinskiy ◽  
А. Е. Morozov

Long-term observations of the drained soil of peat-podzolic-gley light loam on ancient alluvial sands state on the example of the meliorative object "Tinky-2" showed that under the influence of agricultural use in the soil, the organic matter mineralization processes are accelerated. During the drainage process, the soil evolutionarily suffered the following changes: the peat layer was compacted, humified and mineralized, which was a reason of the transformation them into the humus horizon. Based on the monitoring studies results it was established that during 21 intensive use years the peat layer thickness was decreased by 74.5% and amounted to 5.51 inch, which in the following 20 years was decreased to a layer of 1.18 inch, and for another 14 years it became a homogeneous humus horizon containing difficulty identifiable plant remains. For half a century, the bulk density increased by 6 times and the total moisture capacity of the soil decreased by 3.6 times. Other indicators were changed significantly. So, the ash content by 2016 increased from 11.2% to 52.7%. It was a reason of the plough-layer decreasing and it mixes with the mineral sand horizon during plowing. It should also be noted that the total nitrogen content in the soil decreased by 1.13%, and total carbon by 15.3% from 1982 to 2016. The dynamics of changes in the soil acidity, phosphorus and potassium content is associated with the introduction of calcareous, organic and mineral fertilizers in the 1980s. The unsystematic exploitation of such soils leads to decrease in the agricultural products productivity and increase in energy costs. When planning these soils usage in agricultural production, it is necessary to develop and implement modern melioration technologies and techniques aimed to increase soil fertility.


Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.


2021 ◽  
Vol 162 ◽  
pp. 107549
Author(s):  
Weichao Yang ◽  
Xufeng Zhang ◽  
Bing Pan ◽  
Bin Ding ◽  
Binjun Fei ◽  
...  

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