Modeling Grain Crushing and Debonding of Soils

2000 ◽  
Author(s):  
Jaroslav Feda
Keyword(s):  
Grain Crushing

scholarly journals On the progressive nature of grain crushing

2017 ◽  
Vol 140 ◽  
pp. 07006 ◽  
Author(s):  
Matteo O. Ciantia ◽  
Gema Piñero ◽  
Jian Zhu ◽  
Tom Shire
Keyword(s):  
Grain Crushing

WHEAT GRAIN CRUSHING TECHNOLOGY MODERNIZATION

2021 ◽  
pp. 216-222
Author(s):  
Nikita A. Khramovskikh ◽  
Victor N. Nevzorov ◽  
Igor V. Matskevich ◽  
Marina A. Yanova ◽  
Alexander I. Mashanov
Keyword(s):  
Wheat Grain ◽  
Grain Crushing

Creep behavior in Virginia Beach sand

2013 ◽  
Vol 50 (11) ◽  
pp. 1159-1178 ◽  
Author(s):  
Hamid Karimpour ◽  
Poul V. Lade
Keyword(s):  
Triaxial Compression ◽  
Initial Response ◽  
Grain Structure ◽  
Beach Sand ◽  
Static Fatigue ◽  
Compression Tests ◽  
Time Effects ◽  
Grain Crushing ◽  
Virginia Beach ◽  
Confining Pressures

Triaxial compression tests were performed on dense specimens of Virginia Beach sand at low and high confining pressures to study time effects that relate to grain crushing due to static fatigue or delayed fracture. Experiments to study effects of loading strain rate on subsequent creep showed negligible time effects and no grain crushing at low confining pressures, while tests at high confining pressures indicated increasing amounts of creep with increasing initial loading strain rates and with increasing deviator stress at creep. Investigation of effects of grain-size distribution indicated stiffer initial response and smaller amounts of creep for more uniformly graded soils at high confining pressures. The experimental results showed that structuration effects were not present in the dense Virginia Beach sand. A long-term creep test at high confining pressure indicated continuous creep with no indication of its termination. Sieve analyses following each triaxial test showed that grain crushing, as quantified by Hardin’s relative breakage factor, was proportional to energy input and amount of creep observed for each soil specimen. The creep is due to the time-dependent static fatigue by which the grains crush and cause rearrangement of the grain structure, and this is the reason behind the time effects in granular materials.

scholarly journals Satellite data interpretation of causes and controls on groundwater-seawater flow directions, Merseyside, UK: implications for assessing saline intrusions

2005 ◽  
Vol 2 (3) ◽  
pp. 887-916 ◽  
Author(s):  
S. Mukherjee ◽  
E. A. Mohammad ◽  
R. H. Worden
Keyword(s):  
Satellite Data ◽  
Intertidal Zone ◽  
Near Infrared ◽  
Water Movement ◽  
Coastal Region ◽  
Chloride Concentration ◽  
Fault Zones ◽  
Fault Rocks ◽  
Grain Crushing ◽  
Clay Deposits

Abstract. Groundwater in the Triassic Sherwood Sandstone aquifer, Liverpool, UK, has locally elevated chloride concentrations (~4000 mg/l) in parts of the coastal region although there is freshwater right up to the coast line in other areas. The aquifer is cut my numerous faults with vertical displacements of as much 300 m. SPOT satellite data have been used for the Merseyside area of Liverpool. The satellite data revealed and confirmed the location of some of the main faults since the fault zones of the aquifer have low permeability (due to grain crushing, cataclasis, and clay smearing). Where fault zones outcrop at the surface, below the well-developed regolith, there is locally elevated soil water and thus anomalous vegetation patterns in comparison to unfaulted and highly porous aquifer. The ability to identify fault zones by this satellite-based method strongly suggests that they are at least partially sealing, sub-vertical features in the aquifer. Digitally enhanced and processed satellite data were used to define the relative proportions of sand and clay in the near-coastal (inter-tidal) part of the Mersey estuary. Sand-dominated sediment has higher pixel values in comparison with clay deposits in the near infrared spectral region (NIR). Where open and weathered fault rocks crop out at the surface near the intertidal zone, water movement in these potential surface water conduits is limited where the intertidal zone is clay-dominated since clay will plug the conduit. Where these weathered and open fault-rocks crop out against sand-dominated parts of the coastline, fresh water outflux into the seawater has been imaged using the satellite data. Furthermore, the high and low chloride concentration parts of the aquifer are separated by major, sub-vertical fault zones and have allowed a very steep water table gradient to remain in the aquifer.

scholarly journals Evaluation of sand grain crushing in the sand dollar Mellita tenuis (Echinoidea: Echinodermata)

2009 ◽  
Vol 7 ◽  
pp. 261-268 ◽  
Author(s):  
RC Challener ◽  
MF Miller ◽  
DJ Furbish ◽  
J McClintock
Keyword(s):  
Sand Dollar ◽  
Grain Crushing ◽  
Mellita Tenuis

scholarly journals Distribution, microphysical properties, and tectonic controls of deformation bands in the Miocene subduction wedge (Whakataki Formation) of the Hikurangi subduction zone

Solid Earth ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 141-170
Author(s):  
Kathryn E. Elphick ◽  
Craig R. Sloss ◽  
Klaus Regenauer-Lieb ◽  
Christoph E. Schrank
Keyword(s):  
Microstructural Analysis ◽  
Shear Bands ◽  
Normal Faults ◽  
Pore Collapse ◽  
Deformation Bands ◽  
Progressive Deformation ◽  
Compaction Bands ◽  
Microphysical Properties ◽  
Sealing Capacity ◽  
Grain Crushing

Abstract. We analyse deformation bands related to horizontal contraction with an intermittent period of horizontal extension in Miocene turbidites of the Whakataki Formation south of Castlepoint, Wairarapa, North Island, New Zealand. In the Whakataki Formation, three sets of cataclastic deformation bands are identified: (1) normal-sense compactional shear bands (CSBs), (2) reverse-sense CSBs, and (3) reverse-sense shear-enhanced compaction bands (SECBs). During extension, CSBs are associated with normal faults. When propagating through clay-rich interbeds, extensional bands are characterised by clay smear and grain size reduction. During contraction, sandstone-dominated sequences host SECBs, and rare CSBs, that are generally distributed in pervasive patterns. A quantitative spacing analysis shows that most outcrops are characterised by mixed spatial distributions of deformation bands, interpreted as a consequence of overprint due to progressive deformation or distinct multiple generations of deformation bands from different deformation phases. As many deformation bands are parallel to adjacent juvenile normal faults and reverse faults, bands are likely precursors to faults. With progressive deformation, the linkage of distributed deformation bands across sedimentary beds occurs to form through-going faults. During this process, bands associated with the wall-, tip-, and interaction-damage zones overprint earlier distributions resulting in complex spatial patterns. Regularly spaced bands are pervasively distributed when far away from faults. Microstructural analysis shows that all deformation bands form by inelastic pore collapse and grain crushing with an absolute reduction in porosity relative to the host rock between 5 % and 14 %. Hence, deformation bands likely act as fluid flow barriers. Faults and their associated damage zones exhibit a spacing of 9 m on the scale of 10 km and are more commonly observed in areas characterised by higher mudstone-to-sandstone ratios. As a result, extensive clay smear is common in these faults, enhancing the sealing capacity of faults. Therefore, the formation of deformation bands and faults leads to progressive flow compartmentalisation from the scale of 9 m down to about 10 cm – the typical spacing of distributed, regularly spaced deformation bands.

scholarly journals Evaluation of crushing grains of different cultures by bucket elevator

2015 ◽  
Vol 5 (1) ◽  
pp. 244-249
Author(s):  
Шатохин ◽  
Ivan Shatokhin ◽  
Парфенов ◽  
Aleksey Parfenov
Keyword(s):  
Relative Increase ◽  
Physical Damage ◽  
Grain Yields ◽  
Adverse Conditions ◽  
Grain Crushing ◽  
Grain Handling ◽  
Bucket Elevator ◽  
Processing Line ◽  
Different Cultures

One of the factors ensuring sufficient grain is the use of high quality seeds for sowing and harvest preservation at all stages of production. In this case, important value has such indicator of quality of grain, as its damage. According to many researchers grain passing through the machines during post-harvest processing, often has more physical damage than the incoming for processing. When used for sowing seeds is mechanically damaged grain yields is sharply reduced. Under adverse conditions 1 % of injured seeds leads to lower grain yields for 30-50 kg / ha. In this connection, we evaluated the quality of grain handling in terms of crushing of various cultures on the production line of winnowing machine ЗАВ-40 in LLC "Fakel" of Petropavlovsky district of the Voronezh region. The results of crushing grain in bucket elevators during its processing at grain cleaning unit ЗАВ-40 are presented. Also the results of the relative increase in grain crushing in bucket elevators during its processing at grain cleaning unit ЗАВ-40 are presented. It has been established that the considered processing line of postharvest processing of grain should be improved by reducing the number of elevators, or, in extreme cases, opportunities to modernize the elevator in order to reduce damage to the grain should be sought. Moreover, these activities will be particularly significant in the processing of grain and seeds with low strength of the casing, which can be attributed, and sunflower. This fact suggests that the farms must have grain cleaning units not only for the processing of food and seed grain, but also sunflower.

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