Liquefaction Behavior of Dense Sand Relating to the Degree of Saturation

2019 ◽  
pp. 879-886
Author(s):  
Khai Hoan Tran ◽  
Saber Imanzadeh ◽  
Said Taibi ◽  
Duy Lam Dao
Keyword(s):  
Degree Of Saturation ◽  
Dense Sand

INFLUENCE OF CULTIVATION DEGREE OF SOD-PODZOLIC SOIL ON RESPONSIVENESS OF SOWING PEAS TO NITROGEN NUTRITION LEVEL

2020 ◽  
Keyword(s):  
Podzolic Soil ◽  
Nitrogen Nutrition ◽  
Maximum Yield ◽  
Mineral Nitrogen ◽  
Degree Of Saturation ◽  
Cultivated Soil ◽  
Combined Use ◽  
Dry Soil ◽  
Microbial Preparation ◽  
Harvest Maturity

The article presents the results of a vegetation experiment on studying an effect of increasing doses of nitrogen (factor С - N0; No.o5; No.io; N015; No.2o; N0,25 g/kg of absolutely dry soil) and pre-sowing inoculation of seeds with biological preparation "Risotorphine" (factor В - no inoculation; by inoculation) on the formation of vegetative mass and grain yield ofpeas at cultivating in the conditions of a poorly cultivated (factor A0) and of a medium cultivated (factor A f sod-podzolic soil. Cultivation degree of soil was expressed by such criteria as power of an arable horizon, value of metabolic acidity and content of mobile phosphorus, a degree of saturation of soil with bases. For experience tab there were used Mitscher-lich cups with a capacity of 5 kg of absolutely dry soil (a.d.s.), in 16 repetitions of options. The experiments were conducted in the conditions of vegetation site on the territory of University Scientific Centre "Lipogorie" of FSBEI Perm GATA, guided by a science-based methodology. When harvesting peas for a green mass more intensive development and productivity of plants (23.3 and 58.9, 40.0, 78.8 g/cup, respectively) in the phase of stem branching and budding a beginning offlowering that is recorded for its use on the background of inoculation, usage of mineral nitrogen in a dose of 0.10 g/kg on a poorly cultivated soil and 0.15 g/kg a.d.s. on a medium cultivated soil. Applying of higher doses of nitrogen has a depressing effect on development of assimilating surface of pea plants on a poorly and a medium cultivated soil. When raising pea plants before harvest maturity of grain: in the conditions of a poorly cultivated soil for yield at the level of 7.92 g/cup, the process of carrying on only an inoculation of seed with microbial preparation "Rizotorfin" can be considered; in the medium cultivated soil varieties, plant peas impose higher requirements for the level of mineral nutrition the maximum yield in the experiment (which 9.22 g/cup), noted at a combined use of inoculation and mineral nitrogen in a dose of 0.20 g/kg a.d.s.

Ionic liquid-biosurfactant blends as effective dispersants for oil spills: Effect of carbon chain length and degree of saturation

2021 ◽  
pp. 117119
Author(s):  
Mansoor Ul Hassan Shah ◽  
Ambavaram Vijaya Bhaskar Reddy ◽  
Suzana Yusup ◽  
Masahiro Goto ◽  
Muhammad Moniruzzaman
Keyword(s):  
Ionic Liquid ◽  
Chain Length ◽  
Oil Spills ◽  
Carbon Chain ◽  
Degree Of Saturation ◽  
Carbon Chain Length

scholarly journals Dietary Fat Chain Length, Saturation, and PUFA Source Acutely Affect Diet-Induced Thermogenesis but Not Satiety in Adults in a Randomized, Crossover Trial

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2615
Author(s):  
Bret M. Rust ◽  
Susan K. Raatz ◽  
Shanon L. Casperson ◽  
Sara E. Duke ◽  
Matthew J. Picklo
Keyword(s):  
Energy Expenditure ◽  
Dietary Fatty Acids ◽  
Degree Of Saturation ◽  
Postprandial Period ◽  
Men And Women ◽  
Adult Men ◽  
Randomized Crossover Trial ◽  
Structural Differences ◽  
Diet Induced Thermogenesis ◽  
Postprandial Energy Expenditure

Structural differences in dietary fatty acids modify their rate of oxidation and effect on satiety, endpoints that may influence the development of obesity. This study tests the hypothesis that meals containing fat sources with elevated unsaturated fats will result in greater postprandial energy expenditure, fat oxidation, and satiety than meals containing fats with greater saturation. In a randomized, 5-way crossover design, healthy men and women (n = 23; age: 25.7 ± 6.6 years; BMI: 27.7 ± 3.8 kg/m2) consumed liquid meals containing 30 g of fat from heavy cream (HC), olive oil (OO), sunflower oil (SFO), flaxseed oil (FSO), and fish oil (FO). Energy expenditure and diet-induced thermogenesis (DIT) were determined by metabolic rate over a 240 min postprandial period. Serum concentrations of ghrelin, glucose, insulin, and triacylglycerol (TAG) were assessed. DIT induced by SFO was 5% lower than HC and FO (p = 0.04). Energy expenditure and substrate oxidation did not differ between fat sources. Postprandial TAG concentrations were significantly affected by fat source (p = 0.0001). Varying fat sources by the degree of saturation and PUFA type modified DIT but not satiety responses in normal to obese adult men and women.

scholarly journals Design of plate and screw anchors in dense sand: failure mechanism, capacity and deformation

2019 ◽  
Vol 92 ◽  
pp. 16010
Author(s):  
Benjamin Cerfontaine ◽  
Jonathan Knappett ◽  
Michael Brown ◽  
Aaron Bradshaw
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Failure Mechanism ◽  
Progressive Failure ◽  
Vertical Direction ◽  
Shear Plane ◽  
Design Methods ◽  
Embedment Depth ◽  
Limiting State ◽  
Dense Sand

Plate and screw anchors provide a significant uplift capacity and have multiple applications in both onshore and offshore geotechnical engineering. Uplift design methods are mostly based on semi-empirical approaches assuming a failure mechanism, a normal and a shear stress distribution at failure and empirical factors back-calculated against experimental data. However, these design methods are shown to under- or overpredict most of the existing larger scale experimental tests. Numerical FE simulations are undertaken to provide new insight into the failure mechanism and stress distribution which should be considered in anchor design in dense sand. Results show that a conical shallow wedge whose inclination to the vertical direction is equal to the dilation angle is a good approximation of the failure mechanism in sand. This shallow mechanism has been observed in each case for relative embedment ratios (depth/diameter) ranging from 1 to 9. However, the stress distribution varies non-linearly with depth, due to the soil deformability and progressive failure. A sharp peak of normal and shear stress can be identified close to the anchor edge, before a gradual decrease with increasing distance along the shear plane. The peak stress magnitude increases almost linearly with embedment depth at larger relative embedment ratios. Although further research is necessary, these results lay the basis for the development of a new generation of design criteria for determining anchor capacity at the ultimate limiting state.

Bearing Capacity of Foundations with Inclusion of Dense Sand Layer over Loose Sand Strata

2017 ◽  
Vol 17 (10) ◽  
pp. 06017018 ◽  
Author(s):  
Vishwas N. Khatri ◽  
Jyant Kumar ◽  
Shamim Akhtar
Keyword(s):  
Bearing Capacity ◽  
Loose Sand ◽  
Sand Layer ◽  
Dense Sand

Drained instability of sand in plane strain

2010 ◽  
Vol 47 (4) ◽  
pp. 400-412 ◽  
Author(s):  
Dariusz Wanatowski ◽  
Jian Chu ◽  
Wai Lay Loke
Keyword(s):  
Experimental Data ◽  
Plane Strain ◽  
Case Studies ◽  
Static Loading ◽  
State Parameter ◽  
Dam Failure ◽  
Triaxial Tests ◽  
Granular Soil ◽  
Laboratory Studies ◽  
Dense Sand

Flowslide or failure of loose granular soil slopes is often explained using liquefaction or instability data obtained from undrained triaxial tests. However, under static loading conditions, the assumption of an undrained condition is not realistic for sand, particularly clean sand. Case studies have indicated that instability of granular soil can occur under essentially drained conditions (e.g., the Wachusett Dam failure in 1907). Laboratory studies on Changi sand by Chu et al. in 2003 have shown that sand can become unstable under completely drained conditions. However, these studies were carried out under axisymmetric conditions and thus, cannot be applied directly to the analysis of slope failures. In this paper, experimental data obtained from plane-strain tests are presented to study the instability behaviour of loose and dense sand under plane-strain conditions. Based on these test data, the conditions for the occurrence of drained instability in plane strain are established. Using the modified state parameter, the conditions for instability under both axisymmetric and plane-strain conditions can be unified. A framework for interpreting the instability conditions of sandy slopes developed under axisymmetric conditions also extends into plane-strain conditions.

Controls on induced polarization in sandy unconsolidated sediments and application to aquifer characterization

Geophysics ◽  
2003 ◽  
Vol 68 (5) ◽  
pp. 1547-1558 ◽  
Author(s):  
L. D. Slater ◽  
D. R. Glaser
Keyword(s):  
Grain Size ◽  
Hydraulic Conductivity ◽  
Internal Surface ◽  
Ionic Mobility ◽  
Induced Polarization ◽  
Hysteretic Behavior ◽  
Degree Of Saturation ◽  
Unconsolidated Sediments ◽  
Fluid Conductivity ◽  
Grain Diameter

Resistivity and induced polarization (IP) measurements (0.1–1000 Hz) were made on clay‐free unconsolidated sediments from a sandy, alluvial aquifer in the Kansas River floodplain. The sensitivity of imaginary conductivity σ″, a fundamental IP measurement, to lithological parameters, fluid conductivity, and degree of saturation was assessed. The previously reported power law dependence of IP on surface area and grain size is clearly observed despite the narrow lithologic range encountered in this unconsolidated sedimentary sequence. The grain‐size σ″ relationship is effectively frequency independent between 0.1 and 100 Hz but depends on the representative grain diameter used. For the sediments examined here, d90, the grain diameter of the coarsest sediments in a sample, is well correlated with σ″. The distribution of the internal surface in the well‐sorted, sandy sediments investigated here is such that most of the sample weight is likely required to account for the majority of the internal surface. We find the predictive capability of the Börner model for hydraulic conductivity (K)estimation from IP measurements is limited when applied to this narrow lithologic range. The relatively weak dependence of σ″ on fluid conductivity (σw) observed for these sediments when saturated with an NaCl solution (0.06–10 S/m) is consistent with competing effects of surface charge density and surface ionic mobility on σ″ as previously inferred for sandstone. Importantly, IP parameters are a function of saturation and exhibit hysteretic behavior over a drainage and imbibition cycle. However, σ″ is less dependent than the real conductivity σ′ on saturation. In the case of evaporative drying, the σ″ saturation exponent is approximately half of the σ′ exponent. Crosshole IP imaging illustrates the potential for lithologic discrimination of unconsolidated sediments. A fining‐upward sequence correlates with an upward increase in normalized chargeability Mn, a field IP parameter proportional to σ″. The hydraulic conductivity distribution obtained from the Börner model discriminates a hydraulically conductive sand–gravel from overlying medium sand.

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