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| YENICE,HAYATI. |
| Abstract: Drillability is influenced by many factors, including machine parameters and rock properties. The main machine parameters for drilling include rotational speed, thrust force, torque and flush pressure. The specific rock characteristics that affect penetration rate comprise uniaxial compressive strength (UCS), tensile strength, Young’s modulus, hardness and brittleness. In this study, drilling rate index (DRI) is attempted to predict based on UCS and Brazilian tensile strength (BTS) of rocks. Simple and multiple regression analyses have been carried out to determine the best measure of the relation between DRI and two geomechanical properties. The DRI value is strongly related to the uniaxial compressive strength and indirect tensile strength.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Drillability; Uniaxial compressive strength; Tensile strength; Regression analysis. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000500906 |
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| Seben Junior,Getulio de Freitas; Corá,José Eduardo; Lal,Rattan. |
| Abstract The objective of this work was to evaluate the physical quality of an Oxisol under no-tillage subjected to different crop rotations and crop sequences. The experiment was carried out in a clayey Oxisol, during six years, in a randomized complete block design, with strip plots and three replicates. The following physical indicators of soil quality were evaluated: soil density and carbon content, as well as mean weight diameter and tensile strength of aggregates. Treatments consisted of three summer crop rotations - corn/corn (Zea mays), soybean/soybean (Glycine max), and soybean/corn - and of seven second crops (crop sequences) - corn, sunflower (Helianthus annuus), oilseed radish (Raphanus sativus), pearl millet (Pennisetum americanum), pigeon pea... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carbon sequestration; Crop rotation; Diameter of aggregates; Soil density; Soil organic carbon; Tensile strength. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901568 |
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| Cagna,Camila P.; Calábria,Zieglenristen K. P.; Guedes Filho,Osvaldo; Pacheco,Leandro P.; Silva,Tonny J. A. da. |
| ABSTRACT Integration of forage grasses with grain crops, such as maize, allows maintaining soil cover. The objective of this study was to evaluate the tensile strength, friability, and stability of soil aggregates in the maize and forage grass intercropping under no-tillage system. The study used a completely randomized block design with seven treatments and three replications. Undisturbed soil samples were collected in two seasons (2015 and 2016) at 0–0.10 m and 0.10–0.20 m soil depth. The following properties of soil aggregates were measured: tensile strength (TS), friability (F), gravimetric moisture (GM), weighted mean diameter (WMD), geometric mean diameter (GMD), and aggregate stability index (ASI). The intercropping of maize with Urochloa... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aggregate stability index; Tensile strength; Soil physical quality. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000400512 |
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| Tuchtenhagen,Ivana Kruger; Lima,Cláudia Liane Rodrigues de; Bamberg,Adilson Luís; Guimarães,Rachel Muylaert Locks; Mansonia,Pulido-Moncada. |
| ABSTRACT The “Visual Evaluation of Soil Structure” (VESS) is a method used primarily to evaluate the soil structural quality of Oxisols in Brazil and secondly for more specific research, consultancy, and teaching purposes. Since the methodology was never applied and compared with laboratory evaluations of physical properties of hydromorphic soils of the Pampa biome in the south of Brazil, this study evaluated the use of VESS as a visual indicator of the structure quality of a typic eutrophic Albaqualf soil under native grassland, crop-livestock integration, no-tillage, and conventional management systems. Experimental areas with these different management systems were subjected to visual (VESS) and laboratory evaluation of the soil structure. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil degradation; Bulk density; Tensile strength; No-tillage; Conventional tillage. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100412 |
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