Permeability and frictional properties of halite-clay-quartz faults in marine-sediment: The role of compaction and shear

2016 ◽  
Vol 78 ◽  
pp. 222-235 ◽  
Author(s):  
Bryan M. Kaproth ◽  
Marek Kacewicz ◽  
Sankar Muhuri ◽  
Chris Marone
Keyword(s):  
Marine Sediment ◽  
Frictional Properties

scholarly journals The role of effective normal stress, frictional properties, and convergence rates in characteristics of simulated slow slip events

2015 ◽  
Vol 42 (4) ◽  
pp. 1061-1067 ◽  
Author(s):  
W. David Watkins ◽  
Harmony V. Colella ◽  
Michael R. Brudzinski ◽  
Keith B. Richards-Dinger ◽  
James H. Dieterich
Keyword(s):  
Normal Stress ◽  
Convergence Rates ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Frictional Properties ◽  
Effective Normal Stress

scholarly journals Diatom ooze—A large marine mercury sink

Science ◽  
2018 ◽  
Vol 361 (6404) ◽  
pp. 797-800 ◽  
Author(s):  
Sara Zaferani ◽  
Marta Pérez-Rodríguez ◽  
Harald Biester
Keyword(s):  
High Resolution ◽  
Southern Ocean ◽  
Marine Sediment ◽  
Crucial Role ◽  
Anthropogenic Pollution ◽  
Atmospheric Mercury ◽  
Mercury Accumulation ◽  
Accumulation Rates ◽  
Sediment Data

The role of algae for sequestration of atmospheric mercury in the ocean is largely unknown owing to a lack of marine sediment data. We used high-resolution cores from marine Antarctica to estimate Holocene global mercury accumulation in biogenic siliceous sediments (diatom ooze). Diatom ooze exhibits the highest mercury accumulation rates ever reported for the marine environment and provides a large sink of anthropogenic mercury, surpassing existing model estimates by as much as a factor of 7. Anthropogenic pollution of the Southern Ocean began ~150 years ago, and up to 20% of anthropogenic mercury emitted to the atmosphere may have been stored in diatom ooze. These findings reveal the crucial role of diatoms as a fast vector for mercury sequestration and diatom ooze as a large marine mercury sink.

Investigation into the effect of proteoglycan molecules on the tribological properties of cartilage joint tissues

1998 ◽  
Vol 212 (3) ◽  
pp. 177-182 ◽  
Author(s):  
J Pickard ◽  
E Ingham ◽  
J Egan ◽  
J Fisher
Keyword(s):  
Tribological Properties ◽  
Sliding Friction ◽  
Chondroitin Sulphate ◽  
Constant Load ◽  
Compression Tests ◽  
Bovine Articular Cartilage ◽  
Frictional Properties ◽  
Proteoglycan Content ◽  
Bovine Cartilage

The aim of this research was to investigate the role of the hydrophilic properties of the proteoglycan molecules within the cartilage matrix, on the tribological properties of joint tissues in the mixed and boundary lubricating regime. Bovine articular cartilage, bovine meniscus and bovine cartilage that had been degraded to remove the chondroitin sulphate from its proteoglycans were studied in order to investigate differences in their friction and compression responses. The tissues were tested on a sliding friction rig under nominal contact stresses of 0.5 and 4 MPa. The compression tests were carried out under a 0.8 MPa contact stress. The compression tests showed the cartilage and meniscus deforming at the same rates, but the degraded cartilage deformed more quickly to reach its equilibrium position in a shorter period of time. The friction tests carried out at a constant load revealed the friction of the meniscus rising more rapidly with loading time than the cartilage. The degraded cartilage followed an almost identical curve as the untreated cartilage. Although the reduced proteoglycan content of the degraded cartilage substantially altered the biphasic compression response, it did not have an effect on the frictional properties of the tissue.

Frictional properties and slip stability of active faults within carbonate–evaporite sequences: The role of dolomite and anhydrite

2013 ◽  
Vol 369-370 ◽  
pp. 220-232 ◽  
Author(s):  
Marco M. Scuderi ◽  
André R. Niemeijer ◽  
Cristiano Collettini ◽  
Chris Marone
Keyword(s):  
Active Faults ◽  
Frictional Properties

Effect of Texturing on the Friction Characteristic of Carbide and Steel Material by Grinding Process

2017 ◽  
Vol 887 ◽  
pp. 83-88
Author(s):  
Asma Perveen ◽  
Feng Liu
Keyword(s):  
Steel Surface ◽  
Friction Reduction ◽  
Grinding Wheel ◽  
Friction Behavior ◽  
Friction Characteristic ◽  
Frictional Properties ◽  
Steel Material ◽  
Steel Surfaces ◽  
Grooved Wheel

In this paper, friction behavior of textured carbide and steel surface has been studied in order to investigate the effect of different patterns. Several simple textures have been fabricated using straight groove grinding wheel. By microstructuring, various spacing and height of the structure, we investigate the role of topography in terms of friction characteristic. The change of friction behavior has been tailored by grinding operation using straight grooved wheel and evaluated in terms of friction. Friction values were measured by Tribometer. Frictional properties of textured carbide and steel surfaces were assessed with the help of parallel steel slider with 2000g normal force under dry condition using four different sliding speeds. It is found from the experiment that except 30° and 90° angle patterns, rest of the patterns on carbide surfaces show friction reduction which is roughly from 0.15 to 0.13. On the other hand, similar textured patterns can reduce the COF from 0.17 to 0.13 in case of steel surface.

scholarly journals The role of oceanographic processes and sedimentological settings on the deposition of microplastics in marine sediment: Icelandic waters

2021 ◽  
Vol 164 ◽  
pp. 111976
Author(s):  
Christine Loughlin ◽  
Ana R. Marques Mendes ◽  
Liam Morrison ◽  
Audrey Morley
Keyword(s):  
Marine Sediment ◽  
Icelandic Waters

scholarly journals The Effect of Addition of Nanoparticles, Especially ZrO2-Based, on Tribological Behavior of Lubricants

Lubricants ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 23 ◽  
Author(s):  
Adam Rylski ◽  
Krzysztof Siczek
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
The Other ◽  
Zro2 Nanoparticles ◽  
Lubrication Mechanism ◽  
Lithium Grease ◽  
Frictional Properties ◽  
The Difference ◽  
Ball On Disc

The aim of the paper was to discuss different effects, such as, among others, agglomeration of selected nanoparticles, particularly those from zirconia, on the tribological behavior of lubricants. The explanation of the difference between the concepts of ‘aggregation’ and ‘agglomeration’ for ZrO2 nanoparticles is included. The factors that influence such an agglomeration are considered. Classification and thickeners of grease, the role of additives therein, and characteristics of the lithium grease with and without ZrO2 additive are discussed in the paper. The role of nanoparticles, including those from ZrO2 utilized as additives to lubricants, particularly to the lithium grease, is also discussed. The methods of preparation of ZrO2 nanoparticles are described in the paper. The agglomeration of ZrO2 nanoparticles and methods to prevent it and the lubrication mechanism of the lithium nanogrease and its tribological evaluation are also discussed. Sample preparation and a ball-on disc tester for investigating of spinning friction are described. The effect of ZrO2 nanoparticles agglomeration on the frictional properties of the lithium grease is shown. The addition of 1 wt.% ZrO2 nanoparticles to pure lithium grease can decrease the friction coefficient to 50%. On the other hand, the agglomeration of ZrO2 nanoparticles in the lithium grease can increase twice the friction coefficient relative to that for the pure grease.

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