Three-dimensional numerical investigation on micro-meter droplet impact and penetration into the porous media with different velocities

Droplets impacting and penetration into porous media is commonly seen in natural and engineering processes, in which the kinetics and capillary effect are of great importance to the lateral spreading and vertical penetration. In this study, a three-dimensional numerical simulation method was proposed to study the micro-meter droplet impact and penetration into the porous media. It is found that both the lateral spread and vertical penetration occur on the millisecond timescale and larger velocity will enhance the lateral spreading but have little influence on the penetration time and depth. The direct numerical method proposed in this study can be applied to predict the actual spreading and penetration status in the droplet-powder system and further insight into the droplet-powder interaction.

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Structure and function of neural networks in the retina

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102213 ◽

1988 ◽

Vol 46 ◽

pp. 26-27

Author(s):

Peter Sterling

Keyword(s):

Ganglion Cells ◽

Three Dimensional ◽

Structure And Function ◽

Synaptic Connections ◽

Visual Axis ◽

One Dimensional ◽

Cat Retina ◽

Ultrathin Sections ◽

And Function ◽

Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

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Immiscible three-dimensional fingering in porous media: A weakly nonlinear analysis

Physical Review Fluids ◽

10.1103/physrevfluids.3.034002 ◽

2018 ◽

Vol 3 (3) ◽

Cited By ~ 3

Author(s):

Rodolfo Brandão ◽

Eduardo O. Dias ◽

José A. Miranda

Keyword(s):

Porous Media ◽

Nonlinear Analysis ◽

Three Dimensional ◽

Weakly Nonlinear ◽

Weakly Nonlinear Analysis

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Completely non-fused electron acceptor with 3D-interpenetrated crystalline structure enables efficient and stable organic solar cell

Nature Communications ◽

10.1038/s41467-021-25394-w ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lijiao Ma ◽

Shaoqing Zhang ◽

Jincheng Zhu ◽

Jingwen Wang ◽

Junzhen Ren ◽

...

Keyword(s):

Organic Solar Cell ◽

Low Cost ◽

Three Dimensional ◽

Molecular Geometry ◽

Interpenetrating Network ◽

Fused Ring ◽

Molecule Design ◽

End Capping ◽

Conversion Efficiencies ◽

Insight Into

AbstractNon-fullerene acceptors (NFAs) based on non-fused conjugated structures have more potential to realize low-cost organic photovoltaic (OPV) cells. However, their power conversion efficiencies (PCEs) are much lower than those of the fused-ring NFAs. Herein, a new bithiophene-based non-fused core (TT-Pi) featuring good planarity as well as large steric hindrance was designed, based on which a completely non-fused NFA, A4T-16, was developed. The single-crystal result of A4T-16 reveals that a three-dimensional interpenetrating network can be formed due to the compact π–π stacking between the adjacent end-capping groups. A high PCE of 15.2% is achieved based on PBDB-TF:A4T-16, which is the highest value for the cells based on the non-fused NFAs. Notably, the device retains ~84% of its initial PCE after 1300 h under the simulated AM 1.5 G illumination (100 mW cm−2). Overall, this work provides insight into molecule design of the non-fused NFAs from the aspect of molecular geometry control.

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Numerical Study of Three-Dimensional Surface Jets Emerging from a Fishway Entrance Slot

Water ◽

10.3390/w13081079 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1079

Author(s):

Lena Mahl ◽

Patrick Heneka ◽

Martin Henning ◽

Roman B. Weichert

Keyword(s):

Boundary Conditions ◽

Turbulent Flows ◽

Numerical Study ◽

Three Dimensional ◽

Free Water ◽

Lateral Wall ◽

Lateral Spreading ◽

Propagation Length ◽

Vertical Slot ◽

Surface Jets

The efficiency of a fishway is determined by the ability of immigrating fish to follow its attraction flow (i.e., its jet) to locate and enter the fishway entrance. The hydraulic characteristics of fishway entrance jets can be simplified using findings from widely investigated surface jets produced by shaped nozzles. However, the effect of the different boundary conditions of fishway entrance jets (characterized by vertical entrance slots) compared to nozzle jets must be considered. We investigate the downstream propagation of attraction jets from the vertical slot of a fishway entrance into a quiescent tailrace, considering the following boundary conditions not considered for nozzle jets: (1) slot geometry, (2) turbulence characteristics of the approach flow to the slot, and (3) presence of a lateral wall downstream of the slot. We quantify the effect of these boundary conditions using three-dimensional hydrodynamic-numeric flow simulations with DES and RANS turbulence models and a volume-of-fluid method (VoF) to simulate the free water surface. In addition, we compare jet propagation with existing analytical methods for describing jet propagations from nozzles. We show that a turbulent and inhomogeneous approach flow towards a vertical slot reduces the propagation length of the slot jet in the tailrace due to increased lateral spreading compared to that of a jet produced by a shaped nozzle. An additional lateral wall in the tailrace reduces lateral spreading and significantly increases the propagation length. For highly turbulent flows at fishway entrances, the RANS model tends to overestimate the jet propagation compared to the transient DES model.

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Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

Open Geosciences ◽

10.1515/geo-2020-0168 ◽

2020 ◽

Vol 12 (1) ◽

pp. 703-717

Author(s):

Yin Wei ◽

Wang Jiaqi ◽

Bai Xiaomin ◽

Sun Wenjie ◽

Zhou Zheyuan

Keyword(s):

Numerical Simulation ◽

Control Strategy ◽

Three Dimensional ◽

Simulation Method ◽

Mine Pressure ◽

Hydraulic Support ◽

Transition Area ◽

Pressure Concentration ◽

Strata Behavior ◽

And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

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Heat transfer and entropy generation analysis of three-dimensional nanofluids flow in a cylindrical annulus filled with porous media

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2021.105240 ◽

2021 ◽

Vol 124 ◽

pp. 105240

Author(s):

Adel Miles ◽

Rachid Bessaïh

Keyword(s):

Heat Transfer ◽

Porous Media ◽

Entropy Generation ◽

Three Dimensional ◽

Cylindrical Annulus

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Dynamics with Cattaneo–Christov heat and mass flux theory of bioconvection Oldroyd-B nanofluid

Advances in Mechanical Engineering ◽

10.1177/1687814020930464 ◽

2020 ◽

Vol 12 (8) ◽

pp. 168781402093046 ◽

Cited By ~ 2

Author(s):

Noor Saeed Khan ◽

Qayyum Shah ◽

Arif Sohail

Keyword(s):

Mass Transfer ◽

Porous Media ◽

Differential Equations ◽

Mass Flux ◽

Homotopy Analysis Method ◽

Two Dimensional ◽

Analysis Method ◽

Homotopy Analysis ◽

Transfer Flow ◽

Insight Into

Entropy generation in bioconvection two-dimensional steady incompressible non-Newtonian Oldroyd-B nanofluid with Cattaneo–Christov heat and mass flux theory is investigated. The Darcy–Forchheimer law is used to study heat and mass transfer flow and microorganisms motion in porous media. Using appropriate similarity variables, the partial differential equations are transformed into ordinary differential equations which are then solved by homotopy analysis method. For an insight into the problem, the effects of various parameters on different profiles are shown in different graphs.

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The distribution of myosin II in Dictyostelium discoideum slug cells.

The Journal of Cell Biology ◽

10.1083/jcb.115.5.1267 ◽

1991 ◽

Vol 115 (5) ◽

pp. 1267-1274 ◽

Cited By ~ 12

Author(s):

S Eliott ◽

P H Vardy ◽

K L Williams

Keyword(s):

Cell Motility ◽

Dictyostelium Discoideum ◽

Immunofluorescence Microscopy ◽

Molecular Genetic ◽

Myosin Ii ◽

Three Dimensional ◽

Homogeneous Distribution ◽

Multicellular Development ◽

Insight Into

While the role of myosin II in muscle contraction has been well characterized, less is known about the role of myosin II in non-muscle cells. Recent molecular genetic experiments on Dictyostelium discoideum show that myosin II is necessary for cytokinesis and multicellular development. Here we use immunofluorescence microscopy with monoclonal and polyclonal antimyosin antibodies to visualize myosin II in cells of the multicellular D. discoideum slug. A subpopulation of peripheral and anterior cells label brightly with antimyosin II antibodies, and many of these cells display a polarized intracellular distribution of myosin II. Other cells in the slug label less brightly and their cytoplasm displays a more homogeneous distribution of myosin II. These results provide insight into cell motility within a three-dimensional tissue and they are discussed in relation to the possible roles of myosin II in multicellular development.

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