A micromechanical interpretation of the capillary effect of unsaturated granular material in a pendular state

2014 ◽  
pp. 1563-1568
Author(s):  
Ji-Peng Wang ◽  
Xia Li ◽  
Hai-Sui Yu
Keyword(s):  
Granular Material ◽  
Capillary Effect ◽  
Pendular State

Ultra-Rapid Freezing of Isolated Skeletal Muscle Fibers

1977 ◽  
Vol 35 ◽  
pp. 576-577
Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Granular Material ◽  
Nuclear Envelope ◽  
Intracellular Calcium ◽  
Ruthenium Red ◽  
Threshold Concentration ◽  
Rapid Freezing ◽  
Frog Skeletal Muscle ◽  
Electrical Isolation

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Stress fields in granular material and implications for performance of robot locomotion over granular media

2015 ◽  
Vol 8 (1) ◽  
pp. 2005-2009
Author(s):  
Diandong Ren ◽  
Lance M. Leslie ◽  
Congbin Fu
Keyword(s):  
Mechanical Properties ◽  
Granular Material ◽  
Granular Media ◽  
Rotation Frequency ◽  
Legged Locomotion ◽  
Working Environment ◽  
Navier Stokes ◽  
Maximum Speed ◽  
Sigmoid Curve ◽  
Multi Body

 Legged locomotion of robots has advantages in reducing payload in contexts such as travel over deserts or in planet surfaces. A recent study (Li et al. 2013) partially addresses this issue by examining legged locomotion over granular media (GM). However, they miss one extremely significant fact. When the robot’s wheels (legs) run over GM, the granules are set into motion. Hence, unlike the study of Li et al. (2013), the viscosity of the GM must be included to simulate the kinematic energy loss in striking and passing through the GM. Here the locomotion in their experiments is re-examined using an advanced Navier-Stokes framework with a parameterized granular viscosity. It is found that the performance efficiency of a robot, measured by the maximum speed attainable, follows a six-parameter sigmoid curve when plotted against rotating frequency. A correct scaling for the turning point of the sigmoid curve involves the footprint size, rotation frequency and weight of the robot. Our proposed granular response to a load, or the ‘influencing domain’ concept points out that there is no hydrostatic balance within granular material. The balance is a synergic action of multi-body solids. A solid (of whatever density) may stay in equilibrium at an arbitrary depth inside the GM. It is shown that there exists only a minimum set-in depth and there is no maximum or optimal depth. The set-in depth of a moving robot is a combination of its weight, footprint, thrusting/stroking frequency, surface property of the legs against GM with which it has direct contact, and internal mechanical properties of the GM. If the vehicle’s working environment is known, the wheel-granular interaction and the granular mechanical properties can be grouped together. The unitless combination of the other three can form invariants to scale the performance of various designs of wheels/legs. Wider wheel/leg widths increase the maximum achievable speed if all other parameters are unchanged.

scholarly journals Research on the Constitutive Model for Granular Material

2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Wei Zhen-hai ◽  
Wang Meng-shu ◽  
Zhang Ding-li
Keyword(s):  
Constitutive Model ◽  
Granular Material

scholarly journals Capillary Effect Enhancement in a Plastic Capillary Tube by Nanostructured Surface

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 628
Author(s):  
Kazuma Kurihara ◽  
Ryohei Hokari ◽  
Naoki Takada
Keyword(s):  
Plasma Treatment ◽  
Capillary Tube ◽  
Capillary Effect ◽  
Nanostructured Surface ◽  
Nanostructure Fabrication ◽  
Wetting Properties ◽  
Treatment Processes ◽  
Standard Solution ◽  
The Cost ◽  
Plastic Surfaces

We investigated the enhancement of the capillary effect in a plastic capillary tube using only a nanostructured surface. Since plastic is a hydrophobic material, the capillary effect does not emerge without an additional coating or plasma treatment process. Therefore, capillary effect enhancement by the nanostructure fabrication method is expected to reduce the cost and minimise the contamination produced in the human body. By combining a hydrophilic nylon resin and a nanostructure at the tip of the plastic pipette, we could confirm that the capillary effect was produced solely by the tube fabrication process. The produced capillary effect increased linearly with increasing nanostructure height when a standard solution with a surface tension of 70 mN·m−1 was used. Thus, we can conclude that including the plastic part with nanostructure can be useful for biomedical applications. In addition, we suggest that the proposed method is highly effective in controlling the wetting properties of plastic surfaces, compared to the typical coating or plasma treatment processes.

scholarly journals Force chains in crystalline and frustrated packings of uniform spheres visualized by stress-birefringence

Soft Matter ◽  
2021 ◽  
Author(s):  
David Fischer ◽  
Ralf Stannarius ◽  
Karsten Tell ◽  
Peidong Yu ◽  
Matthias Sperl
Keyword(s):  
Granular Material ◽  
Force Chains ◽  
Force Networks ◽  
The Stability

Force networks play an important role in the stability of configurations when granular material is packed into a container. These networks can redirect part of the weight of grains inside...

Sign in / Sign up

Export Citation Format

Share Document