scholarly journals Simulation of Soil Compaction by a Tractor Passing

2021 ◽  
Vol 906 (1) ◽  
pp. 012105
Author(s):  
Pavla Bukovská ◽  
Patrik Burg ◽  
Vladimir Masán ◽  
Alice Cížková
Keyword(s):  
Cyclic Loading ◽  
Soil Compaction ◽  
Agricultural Soil ◽  
Elastic Behaviour ◽  
Soil Conditions ◽  
Vertical Deformation ◽  
Vertical Deflection ◽  
Loading Test ◽  
Final Level ◽  
Good Potential

Abstract Several methods for agricultural soil compaction evaluation are known. However, there is a lack of knowledge about a soil elasticity, which could be an important factor for final level of compaction. The paper deals with a possibility of evaluation of soil elasticity using automatic computerized oedometer. A simulation of tractor passing was performed as a part of research focused on the monitoring of soil conditions in vineyards. Cyclic loading test of five loading cycles (loading 300 kPa and un-loading 5 kPa) was performed and vertical deflection was observed, which changed in dependency on change of vertical stress. Course of vertical deformation indicates the ability of soil to relax when the load subsides. The paper presents pilot results, that show good potential of using oedometer for soil elasticity evaluating. Information on the elastic behaviour of soil will make it possible to design and apply means for improving soil elasticity and thus help to mitigate the effects of soil compaction.

Discrete element modeling of deformable pinewood chips in cyclic loading test

2019 ◽  
Vol 345 ◽  
pp. 1-14 ◽  
Author(s):  
Yidong Xia ◽  
Zhengshou Lai ◽  
Tyler Westover ◽  
Jordan Klinger ◽  
Hai Huang ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Discrete Element ◽  
Discrete Element Modeling ◽  
Loading Test ◽  
Cyclic Loading Test ◽  
Element Modeling

REGRESSION ANALYSES OF GRAIN YIELD OF CORN, LEVEL OF LEAF N P K AND SOIL CONDITIONS IN A LONG-TIME ROTATION EXPERIMENT ON BROOKSTON CLAY

1980 ◽  
Vol 60 (4) ◽  
pp. 599-611 ◽  
Author(s):  
V. A. DIRKS ◽  
E. F. BOLTON
Keyword(s):  
Soil Moisture ◽  
Grain Yield ◽  
Soil Compaction ◽  
Nutrient Level ◽  
Soil Conditions ◽  
Fertilizer Treatment ◽  
Long Time ◽  
Yield Difference ◽  
Soil Measurements ◽  
Leaf N

Regression and covariance analysis of a 13-yr rotation experiment of corn on Brookston clay soil showed that grain yield of corn could be related to each of nine other plant and soil measurements. Soil compaction as measured by bulk density was negatively associated with the level of leaf K in the plants, as well as available soil moisture. The major part of the yield difference between fertilized continuous corn and fertilized corn following alfalfa could be accounted for by multiple regression of grain yield on leaf N and K nutrient levels, soil compaction and soil moisture. Soil compaction was not affected or modified by fertilizer treatment. Response of corn grain yield to soil conditions, moisture and plant nutrient level appears to vary with rotation and fertilizer input.

scholarly journals Biomechanical comparison of medial sustainable nail and proximal femoral nail antirotation in the treatment of an unstable intertrochanteric fracture

2020 ◽  
Vol 9 (12) ◽  
pp. 840-847
Author(s):  
Shaobo Nie ◽  
Ming Li ◽  
Hui Ji ◽  
Zhirui Li ◽  
Wenwen Li ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Torsional Stiffness ◽  
Proximal Femoral Nail ◽  
Axial Stiffness ◽  
Intertrochanteric Fractures ◽  
Loading Test ◽  
Cyclic Loading Test ◽  
Femoral Nail ◽  
Unstable Intertrochanteric Fracture ◽  
The Mean

Aims Restoration of proximal medial femoral support is the keystone in the treatment of intertrochanteric fractures. None of the available implants are effective in constructing the medial femoral support. Medial sustainable nail (MSN-II) is a novel cephalomedullary nail designed for this. In this study, biomechanical difference between MSN-II and proximal femoral nail anti-rotation (PFNA-II) was compared to determine whether or not MSN-II can effectively reconstruct the medial femoral support. Methods A total of 36 synthetic femur models with simulated intertrochanteric fractures without medial support (AO/OTA 31-A2.3) were assigned to two groups with 18 specimens each for stabilization with MSN-II or PFNA-II. Each group was further divided into three subgroups of six specimens according to different experimental conditions respectively as follows: axial loading test; static torsional test; and cyclic loading test. Results The mean axial stiffness, vertical displacement, and maximum failure load of MSN-II were 258.47 N/mm (SD 42.27), 2.99 mm (SD 0.56), and 4,886 N (SD 525.31), respectively, while those of PFNA-II were 170.28 N/mm (SD 64.63), 4.86 mm (SD 1.66), and 3,870.87 N (SD 552.21), respectively. The mean torsional stiffness and failure torque of MSN-II were 1.72 N m/° (SD 0.61) and 16.54 N m (SD 7.06), respectively, while those of PFNA-II were 0.61 N m/° (SD 0.39) and 6.6 N m (SD 6.65), respectively. The displacement of MSN-II in each cycle point was less than that of PFNA-II in cyclic loading test. Significantly higher stiffness and less displacement were detected in the MSN-II group (p < 0.05). Conclusion The biomechanical performance of MSN-II was better than that of PFNA-II, suggesting that MSN-II may provide more effective mechanical support in the treatment of unstable intertrochanteric fractures. Cite this article: Bone Joint Res 2020;9(12):840–847.

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