scholarly journals Wall friction and Janssen effect in the solidification of suspensions

Soft Matter ◽  
2018 ◽  
Vol 14 (46) ◽  
pp. 9498-9510 ◽  
Author(s):  
Brice Saint-Michel ◽  
Marc Georgelin ◽  
Sylvain Deville ◽  
Alain Pocheau
Keyword(s):  
Solidification Front ◽  
Wall Friction ◽  
Compact Layer ◽  
Janssen Effect

Janssen effect on a compact layer of particles formed ahead of the solidification front of a freezing suspension.

Kinetics of compact layer formation and growth of 1,10-phenanthroline at the electrode surface

1990 ◽  
Vol 87 ◽  
pp. 1597-1607 ◽  
Author(s):  
L Benedetti ◽  
M Borsari ◽  
C Fontanesi ◽  
G Battistuzzi Gavioli
Keyword(s):  
Electrode Surface ◽  
Layer Formation ◽  
Compact Layer ◽  
Kinetics Of

The Influence of Disintegration of Hard Coal Varieties of Different Metamorphism Grade on the Amount of Sorbed Ethane / Wpływ rozdrobnienia odmian węgla kamiennego o różnym stopniu metamorfizmu na ilości sorbowanego etanu

2013 ◽  
Vol 58 (2) ◽  
pp. 449-463 ◽  
Author(s):  
Mieczysław Żyła ◽  
Agnieszka Dudzińska ◽  
Janusz Cygankiewicz
Keyword(s):  
Sorption Isotherms ◽  
Electron Donors ◽  
Hard Coal ◽  
Coal Surface ◽  
Compact Layer ◽  
Compact Structure ◽  
Small Surface ◽  
Mining Works ◽  
The Impact ◽  
Content Of Oxygen

Ethane constitutes an explosive gas. It most often accompanies methane realizing during exploitation and mining works. In this paper the results of ethane sorption have been discussed on three grain classes of six selected hard coal samples collected from active Polish coalmines. On the basis of obtained results, it has been stated that the tested hard coals prove differentiated sorption power with reference to ethane. Te extreme amount of ethane is sorbed by low carbonized hard coal from “Jaworzno” coalmine. This sort of coal shows great porosity, and great content of oxygen and moisture. The least amount of ethane is sorbed by hard coal from “Sośnica” coalmine. This sort of coal possesses relatively a great deal of ash contents. Together with the process of coal disintegration, the amount of sorbed ethane increases for all tested coal samples. Between tested coals there are three medium carbonized samples collected from “Pniówek”, “Chwałowice” “Zofiówka” coalmines which are characterized by small surface values counted according to model BET from nitrogen sorption isotherms determined at the temperature of 77.5 K. The samples of these three coals prove the highest, from between tested coals, increase of ethane sorption occurring together with their disintegration. These samples disintegrated to 0,063-0,075 mm grain class sorb ethane in the amount corresponding with the sorption quantity of low carbonized coal from “Jaworzno” coalmine in 0.5-0.7 mm grain class. It should be marked that the low carbonized samples collected from “Jaworzno” and Wesoła” coalmines possess large specific surface and great porosity and belong to coal group of “loose” spatial structure. Regarding profusion of sorbed ethane on disintegrated medium carbonized samples from “Pniówek”, “Zofiówka”, “Chwałowice” coalmines it can be supposed that in the process of coal disintegration, breaking their “compact’ structure occurs. Loosened structure of medium carbonized coals results in increasing accessibility of ethane particles to sorption centres both electron donors and electron acceptors which are present on hard coal surface. The surface sorption centre increase may result in formation a compact layer of ethane particles on coal surface. In the formed layer, not only the strengths of vertical binding of ethane particles with the coal surface appear but also the impact of horizontal strengths appears which forms a compact layer of sorbed ethane particles. The surface layer of ethane particles may lead to explosion.

Quantitative effects of projectile-launch tube wall friction on ballistic tange operation

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1709-1715
Author(s):  
Akihiro Sasoh ◽  
Shinji Ohba ◽  
Kazuyoshi Takayama
Keyword(s):  
Tube Wall ◽  
Wall Friction ◽  
Launch Tube

Modeling and performance analysis of dye-sensitized solar cell based on ZnO compact layer and TiO2 photoanode

2021 ◽  
Author(s):  
Ayodeji.Olalekan Salau ◽  
Ademola Stanford Olufemi ◽  
Gabriel Oluleye ◽  
Victor Adewale Owoeye ◽  
Isiaka Ismail
Keyword(s):  
Solar Cell ◽  
Performance Analysis ◽  
Dye Sensitized Solar Cell ◽  
Compact Layer ◽  
Dye Sensitized ◽  
And Performance ◽  
Tio2 Photoanode

scholarly journals Magnetic Janssen effect

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
L. Thorens ◽  
K. J. Måløy ◽  
M. Bourgoin ◽  
S. Santucci
Keyword(s):  
Magnetic Field ◽  
Dynamic Properties ◽  
Radial Force ◽  
Fine Tuning ◽  
Apparent Mass ◽  
Confined Geometries ◽  
Pairwise Interactions ◽  
Janssen Effect ◽  
Lateral Walls ◽  
Granular Column

AbstractA pile of grains, even when at rest in a silo, can display fascinating properties. One of the most celebrated is the Janssen effect, named after the pioneering engineer who explained the pressure saturation at the bottom of a container filled with corn. This surprising behavior arises because of frictional interactions between the grains through a disordered network of contacts, and the vessel lateral walls, which partially support the weight of the column, decreasing its apparent mass. Here, we demonstrate control over frictional interactions using ferromagnetic grains and an external magnetic field. We show that the anisotropic pairwise interactions between magnetized grains result in a radial force along the walls, whose amplitude and direction is fully determined by the applied magnetic field. Such magnetic Janssen effect allows for the fine tuning of the granular column apparent mass. Our findings pave the way towards the design of functional jammed materials in confined geometries, via a further control of both their static and dynamic properties.

Application of generalized Fourier heat conduction law on MHD viscoinelastic fluid flow over stretching surface

2019 ◽  
Vol 30 (6) ◽  
pp. 3481-3496 ◽  
Author(s):  
Arif Hussain ◽  
Muhammad Yousaf Malik ◽  
Mair Khan ◽  
Taimoor Salahuddin
Keyword(s):  
Heat Flux ◽  
Fluid Flow ◽  
Friction Factor ◽  
Numerical Technique ◽  
Wall Heat Flux ◽  
Constitutive Law ◽  
Wall Friction ◽  
Theoretical Physics ◽  
Stretching Surface ◽  
Content Type

Purpose The purpose of current flow configuration is to spotlights the thermophysical aspects of magnetohydrodynamics (MHD) viscoinelastic fluid flow over a stretching surface. Design/methodology/approach The fluid momentum problem is mathematically formulated by using the Prandtl–Eyring constitutive law. Also, the non-Fourier heat flux model is considered to disclose the heat transfer characteristics. The governing problem contains the nonlinear partial differential equations with appropriate boundary conditions. To facilitate the computation process, the governing problem is transmuted into dimensionless form via appropriate group of scaling transforms. The numerical technique shooting method is used to solve dimensionless boundary value problem. Findings The expressions for dimensionless velocity and temperature are found and investigated under different parametric conditions. The important features of fluid flow near the wall, i.e. wall friction factor and wall heat flux, are deliberated by altering the pertinent parameters. The impacts of governing parameters are highlighted in graphical as well as tabular manner against focused physical quantities (velocity, temperature, wall friction factor and wall heat flux). A comparison is presented to justify the computed results, it can be noticed that present results have quite resemblance with previous literature which led to confidence on the present computations. Originality/value The computed results are quite useful for researchers working in theoretical physics. Additionally, computed results are very useful in industry and daily-use processes.

scholarly journals Gross morphology and microstructure of type locality ossicles of Psephophorus polygonus Meyer, 1847 (Testudines, Dermochelyidae)

2013 ◽  
Vol 150 (5) ◽  
pp. 767-782 ◽  
Author(s):  
MASSIMO DELFINO ◽  
TORSTEN M. SCHEYER ◽  
FRANCESCO CHESI ◽  
TAMARA FLETCHER ◽  
RICHARD GEMEL ◽  
...  
Keyword(s):  
Middle Miocene ◽  
Ventral Surface ◽  
Dive Depth ◽  
Type Locality ◽  
Dermochelys Coriacea ◽  
Compact Layer ◽  
Leatherback Turtle ◽  
New Diagnosis ◽  
First Time ◽  
Growth Centres

AbstractPsephophorus polygonus Meyer, 1847, the first fossil leatherback turtle to be named, was described on the basis of shell ossicles from the middle Miocene (MN6–7/8?) of Slovakia. The whereabouts of this material is uncertain but a slab on display at the Naturhistorisches Museum Wien is considered the neotype. We rediscovered further type locality ossicles in four European institutions, re-evaluated their gross morphology and described for the first time their microstructure by comparing them with Dermochelys coriacea, the only living dermochelyid turtle. The gross morphology is congruent with that already described for P. polygonus, but with two significant exceptions: the ridged ossicles of P. polygonus may have a distinctly concave ventral surface as well as a tectiform shape in cross-section. They do not develop the external keel typical of many ossicles of D. coriacea. Both ridged and non-ridged ossicles of P. polygonus are characterized by compact diploe structures with an internal cortex consisting of a coarse fibrous meshwork, whereas the proportionately thinner ossicles of D. coriacea tend to lose the internal cortex, and thus their diploe, during ontogeny. The ossicles of both P. polygonus and D. coriacea differ from those of other lineages of amniotes whose carapace is composed of polygonal ossicles or platelets, in having growth centres situated at the plate centres just interior to the external bone surface and not within the cancellous core or closer to the internal compact layer. The new diagnosis of P. polygonus allows us to preliminarily re-evaluate the taxonomy of some of the Psephophorus-like species. Despite some macro- and micromorphological differences, it seems likely that Psephophorus was as cosmopolitan as extant Dermochelys and had a broadly similar ecology, with a possible difference concerning the dive depth.

Kinetics of Growth and Structure of Coatings Obtained on Sandelin Steels in the High-Temperature Galvanizing Process

2013 ◽  
Vol 212 ◽  
pp. 127-132 ◽  
Author(s):  
Henryk Kania
Keyword(s):  
High Temperature ◽  
Growth Kinetics ◽  
Structural Components ◽  
Compact Layer ◽  
Two Phase ◽  
Continuous Layer ◽  
Structure Of Coatings ◽  
Zinc Coatings ◽  
Kinetics Of ◽  
Diffuse Coating

In the paper the author presents the results of tests defining the characteristics of behaviour of Sandelin steel in the high-temperature galvanizing process. The growth kinetics of hot-dip zinc coatings on the substrate of 0.05% Si steel in the temperature range of 540-580°C has been established. The structure of the coatings and their phase composition have been developed and the chemical composition of structural components of the coating has be defined. It has been determined that the coating is composed of a compact layer δ1 and an area of a two-phase mixture of δ1 and Zn. The conducted tests confirmed the presence of phase Γ1 , which does not form a continuous layer but it forms individual precipitates which are irregular in shape. The growth kinetics of the coating indicates that an increase in temperature causes a decrease in the coating thickness, which might prove that dissolving processes prevailed over the processes of diffuse coating growth.

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