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| Registros recuperados: 12 | |
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| Kamandar, Mohammad Reza; Massah, Jafar. |
| The knowing of the shearing properties of buxus stalk have important role in the design and fabricate of buxus pruning machine. A series of laboratory tests were conducted to measure the shear force, shear consumption energy and shear strength of stem internodes of buxus stalk under impact cutting at four loading rates: 1, 2, 3 and 4 m/s, three internodes: fifth, tenth and fifteenth and moisture content level 72% wet base. In this test, the stalk specimens were served in impact cutting process by using a special cutting test apparatus that was designed, fabricated, and calibrated. To define the impact cutting force of buxus stem, the apparatus was attached with beam type load cell and shear blade. The variance analysis of the data results showed that the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Buxus stem; Impact cutting; Shear energy; Shear force; Shear strength. |
| Ano: 2018 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/4237 |
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| Azadbakht, Mohsen; Ghajarjazi, Ehsan; Barzanooni, Esmat; Pourbagher, Roghayeh; Tajari, Neda. |
| Three irrigation regimes, 6, 12 and 18 days, the distance between seeds in four levels: 5,10, 15 and 20 cm (density, respectively, 80, 40, 27 and 20 plants per m2) and a row spacing of 25 cm was considered that was tested in a randomized complete block design with three replications. The results showed that the effect of irrigation on cutting force, shear strength and energy per unit area was meaningful at 5% level and the effect of plant density on cutting force was meaningful at 1% level, but was not meaningful on shear strength. Also showed interaction between irrigation and plant density on cutting force, shear strength and energy per unit area is not meaningful. It was observed that the effect of irrigation and plant density on the length, diameter... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Azivash; Plant density; Shear strength; Irrigation regime. |
| Ano: 2015 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3340 |
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| Azadbakht, Mohsen; Torshizi, Mohammad Vahedi; Ziaratban, Armin; Ghajarjazi, Ehsan. |
| In this study, at first the shear parameters including the maximum shear force, shear strength, shear energy and power consumption of canola stem were calculated through force-deformation curve; and then these mechanical properties were determined and predicted using artificial neural network. For the tests, testing machine Instron (Model Santam STM-5) with 50 N load cell was used. Stems were cut at 3 diameter levels (1 to 3, 3 to 5 and more than 5 mm), 3 cutting speed levels (75, 115 and 150 mm/min ), 3 cutting angles (0°, 30° and 60°) and three replicates. Cutting parameters including maximum cutting force, shear strength; cutting energy; consumed power and cutting work were examined. Tests lasted for each stem until the full cut. Data... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Canola; Cutting energy; Stem; Shear strength; Power consumption; Artificial Neural Network (ANN). |
| Ano: 2016 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3785 |
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| Vanneste, Maarten; Sultan, Nabil; Garziglia, Sebastien; Forsberg, Carl Fredrik; L'Heureux, Jean-sebastien. |
| In this paper, we present the current practice of investigations of seafloor instabilities and deformation processes, based on extensive research conducted over the last years, which sets the scene for future research activities in this field. The mapping of the continental margins and coastal areas with ever increasing resolution systematically reveals evidence of instabilities and deformation processes, both active and palaeo-features. In order to properly assess the hazards and risks related to these features, an integrated and multi-disciplinary approach is essential, but challenging. Such an approach consists of combining field data (geophysics, geology, sedimentology, geochemistry and geotechnical data) with numerical simulations constrained by... |
| Tipo: Text |
Palavras-chave: Marine geotechnics; Slope stability; Sediment failures; Fluid flow; Shear strength; Marine geophysics; Monitoring; Excess pore pressure; Site investigations. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28378/26692.pdf |
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| Sultan, Nabil; Garziglia, Sebastien. |
| Multi-phase fluid conditions encountered in geotechnical and geo-environmental problems have led to the development of models that account for the influence of gas solubility and compressibility on the behaviour of soils of various grain sizes. Yet, no consideration has been given to damages related to the nucleation and growth of gas bubbles in fine-grained soils. The purpose of this paper is to present a Cam Clay based constitutive model extended to incorporate such detrimental effects on gassy soils. This is achieved by deriving an analytical expression relating the preconsolidation pressure to a damage parameter dependent on the gas content. That expression is coupled to a deviatoric yield surface accounting for inherent and stress-induced anisotropy.... |
| Tipo: Text |
Palavras-chave: Compressibility; Constitutive relations; Offshore engineering; Shear strength. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00245/35621/34133.pdf |
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| Sultan, Nabil; Cattaneo, Antonio; Urgeles, R; Lee, H; Locat, J; Trincardi, F; Berne, Serge; Canals, M; Lafuerza, S. |
| This study is among the first to examine the genesis of the seafloor and subsurface undulations on the Adriatic continental shelf by integrating stratigraphic information and in situ and laboratory geotechnical measurements. Interpretation of sediment behavior is based on a 32-m-long borehole crossing ( 1) a possible shear plane and ( 2) a silty clay layer at about 20 m below seafloor (mbsf) on which sediment undulations are rooted and could be interpreted as a potential weak layer succession. Our main results in terms of triggering mechanism for the observed undulations show that under an earthquake, liquefaction and/or failure of the silty-clay sediments ( weak layer) leading to deformation of the upper more cohesive sediments is possible only when such... |
| Tipo: Text |
Palavras-chave: Sediment deformation; Shear strength; Earthquake; Adriatic shelf. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4105.pdf |
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| Winters, W. J.; Wilcox-cline, R. W.; Long, P.; Dewri, S. K.; Kumar, P.; Stern, L.; Kerr, L.. |
| The sediment characteristics of hydrate-bearing reservoirs profoundly affect the formation, distribution, and morphology of gas hydrate. The presence and type of gas, porewater chemistry, fluid migration, and subbottom temperature may govern the hydrate formation process, but it is the host sediment that commonly dictates final hydrate habit, and whether hydrate may be economically developed. In this paper, the physical properties of hydrate-bearing regions offshore eastern India (Krishna-Godavari and Mahanadi Basins) and the Andaman Islands, determined from Expedition NGHP-01 cores, are compared to each other, well logs, and published results of other hydrate reservoirs. Properties from the hydrate-free Kerala-Konkan basin off the west coast of India are... |
| Tipo: Text |
Palavras-chave: Physical properties; Gas hydrate; Porosity; Atterberg limits; Consolidation; Permeability; Shear strength; Scanning electron microscopy. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00289/40036/38799.pdf |
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| Vanoudheusden, Emilie; Sultan, Nabil; Cochonat, Pierre. |
| The COSTA target areas exhibit different slope failure events, which reflect different triggering mechanisms including gas hydrates dissociation. Gas hydrates stability law depends on temperature, pore pressure, gas chemistry, and pore water salinity. Any change in the equilibrium parameters may convert the hydrate to gas plus water, causing significant weakening of the sediment, and generating a rise of pore pressure. A significant consequence of the hydrate melting is the gas production, which alters significantly the behaviour and mechanical properties of the marine sediments and could be very hazardous when the sediment is unloaded in undrained conditions. The behaviour of the unsaturated marine sediment has to be accurately identified in order to... |
| Tipo: Text |
Palavras-chave: Shear strength; Andrained behaviour; Triaxial tests; Capillary pressure; Unsaturated sediment. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-701.pdf |
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| Sultan, Nabil; Cui, Y. -j.; Delage, P.. |
| An underground research laboratory (URL) has been excavated in a deposit of Boom clay at a depth of 223 m by the SCK-CEN Belgian organisation near the city of Mol. This URL is devoted to research into nuclear waste disposal. This paper presents the results of an investigation carried out in the triaxial apparatus on specimens that were trimmed from blocks extracted during excavation sequences in the URL. In order to characterise the mechanical behaviour of the natural Boom clay and to examine the effect of initial and induced anisotropy on its constitutive behaviour, two series of triaxial tests were carried out. Special attention was devoted to the yield behaviour and the effects of stress history. Experimental results showed a clear relation between the... |
| Tipo: Text |
Palavras-chave: Anisotropy; Clays; Constitutive relations; Elasticity; Laboratory tests; Plasticity; Shear strength. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12414/9530.pdf |
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| Sultan, Nabil; Cochonat, Pierre; Bourillet, Jean-francois; Cayocca, Florence. |
| This article presents a methodology developed to evaluate the instability of submarine slopes that extend over a large area. Special attention was paid to (1) the complex geometry (bathymetry) and the expanse of the slope, (2) the heterogeneity of the sediment, and (3) the distribution of the pore pressure. The safety factor was considered as a spatially varying quantity. The General Formulation (GLE, Fredlund and Krahn 1977), which fully satisfies equilibrium conditions, was used for evaluating the stability of the marine slope. The submarine slope failure, which occurred on 16 October 1979 during the construction of the new Nice airport, was studied in order to test the developed model. Geotechnical parameters were taken from experimental tests carried... |
| Tipo: Text |
Palavras-chave: Shear strength; Slope stability; Safety factor; Marine sediment; Finite element; Finite difference; Failure. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-698.pdf |
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| Registros recuperados: 12 | |
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