Interface pullout resistance of polymeric strips embedded in marginal tropical soils

Author(s):  
R.C. Pierozan ◽  
G.L.S. Araujo ◽  
E.M. Palmeira ◽  
C. Romanel ◽  
J.G. Zornberg
2013 ◽  
Vol 27 (3) ◽  
pp. 239-246 ◽  
Author(s):  
A.E. Ajayi ◽  
M.S. Dias Junior ◽  
N. Curi ◽  
I. Oladipo

Abstract This study aimed to investigate the mineralogy, moisture retention, and the compressive response of two agricultural soils from South West Nigeria. Undisturbed soil cores at the A and B horizons were collected and used in chemical and hydrophysical characterization and confined compression test. X-ray diffractograms of oriented fine clay fractions were also obtained. Our results indicate the prevalence of kaolinite minerals relating to the weathering process in these tropical soils. Moisture retention by the core samples was typically low with pre-compression stress values ranging from50 to 300 kPa at both sites. Analyses of the shape of the compression curves highlight the influence of soil moisture in shifts from the bi-linear to S-shaped models. Statistical homogeneity test of the load bearing capacity parameters showed that the soil mineralogy influences the response to loading by these soils. These observations provide a physical basis for the previous classification series of the soils in the studied area. We showed that the internal strength attributes of the soil could be inferred from the mineralogical properties and stress history. This could assist in decisions on sustainable mechanization in a datapoor environment.


Mycologia ◽  
1969 ◽  
Vol 61 (2) ◽  
pp. 264 ◽  
Author(s):  
D. P. Mahoney ◽  
L. H. Huang ◽  
M. P. Backus
Keyword(s):  

2021 ◽  
pp. 100220
Author(s):  
Juliana Teles Diniz Gonçalves ◽  
Marco Antonio Barsottelli Botelho ◽  
Sandro Lemos Machado ◽  
Leonides Guireli Netto

Sensors ◽  
2011 ◽  
Vol 11 (5) ◽  
pp. 4858-4874 ◽  
Author(s):  
Ali Fares ◽  
Farhat Abbas ◽  
Domingos Maria ◽  
Alan Mair
Keyword(s):  

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Sheng Tang ◽  
Kefeng Han ◽  
Ping He ◽  
...  

Nutrient requirements for single-season rice using the quantitative evaluation of the fertility of tropical soils (QUEFTS) model in China have been estimated in a previous study, which involved all the rice varieties; however, it is unclear whether a similar result can be obtained for different rice varieties. In this study, data were collected from field experiments conducted from 2016 to 2019 in Zhejiang Province, China. The dataset was separated into two parts: japonica/indica hybrid rice and japonica rice. To produce 1000 kg of grain, 13.5 kg N, 3.6 kg P, and 20.4 kg K were required in the above-ground plant dry matter for japonica/indica hybrid rice, and the corresponding internal efficiencies (IEs) were 74.0 kg grain per kg N, 279.1 kg grain per kg P, and 49.1 kg grain per kg K. For japonica rice, 17.6 kg N, 4.1 kg P, and 23.0 kg K were required to produce 1000 kg of grain, and the corresponding IEs were 56.8 kg grain per kg N, 244.6 kg grain per kg P, and 43.5 kg grain per kg K. Field validation experiments indicated that the QUEFTS model could be used to estimate nutrient uptake of different rice varieties. We suggest that variety should be taken into consideration when estimating nutrient uptake for rice using the QUEFTS model, which would improve this model.


1997 ◽  
Vol 69 (6) ◽  
pp. 1349-1372 ◽  
Author(s):  
K. D. Racke ◽  
M. W. Skidmore ◽  
D. J. Hamilton ◽  
J. B. Unsworth ◽  
J. Miyamoto ◽  
...  

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