Equilibrium morphology and scour evolution at blunt nosed chevrons

2021 ◽  
Author(s):  
Deep Roy ◽  
Simone Pagliara
Keyword(s):  
Equilibrium Morphology

Transition alpha structure in beta-isomorphous Nb-Hf alloys

1987 ◽  
Vol 45 ◽  
pp. 232-233
Author(s):  
R.W. Carpenter ◽  
Changhai Li ◽  
David J. Smith
Keyword(s):  
Solid Solution ◽  
Solution Phase ◽  
Miscibility Gap ◽  
Large Strains ◽  
Solid Solution Phase ◽  
Two Phase ◽  
Diffuse Intensity ◽  
Metastable Form ◽  
The Matrix ◽  
Equilibrium Morphology

Binary Nb-Hf alloys exhibit a wide bcc solid solution phase field at temperatures above the Hfα→ß transition (2023K) and a two phase bcc+hcp field at lower temperatures. The β solvus exhibits a small slope above about 1500K, suggesting the possible existence of a miscibility gap. An earlier investigation showed that two morphological forms of precipitate occur during the bcc→hcp transformation. The equilibrium morphology is rod-type with axes along <113> bcc. The crystallographic habit of the rod precipitate follows the Burgers relations: {110}||{0001}, <112> || <1010>. The earlier metastable form, transition α, occurs as thin discs with {100} habit. The {100} discs induce large strains in the matrix. Selected area diffraction examination of regions ∼2 microns in diameter containing many disc precipitates showed that, a diffuse intensity distribution whose symmetry resembled the distribution of equilibrium α Bragg spots was associated with the disc precipitate.

scholarly journals Emergence and Migration of a Nearshore Bar: Sediment Flux and Morphological Change on a Multi-Barred Beach in the Great Lakes

2007 ◽  
Vol 60 (1) ◽  
pp. 31-47 ◽  
Author(s):  
Brian Greenwood ◽  
Allana Permanand-Schwartz ◽  
Christopher A. Houser
Keyword(s):  
Great Lakes ◽  
Suspended Sediment ◽  
Surf Zone ◽  
Sandy Beaches ◽  
Sediment Flux ◽  
Accommodation Space ◽  
Longshore Transport ◽  
Sediment Balance ◽  
And Migration ◽  
Equilibrium Morphology

Abstract Burley Beach (southeastern Lake Huron) exhibits a multi-barred shoreface, the long-term equilibrium morphology characteristic of many low angle, sandy beaches in the Canadian Great Lakes. During a single major storm, a new bar emerged 50-60 m offshore as an irregular trough-crest form, through differential erosion of an existing shore terrace. Emergence, bar growth and offshore migration were associated with: (a) an overall negative sediment balance in the inner surf zone initially (‑2.30 m3>/m beach width), but with a large positive sediment balance (+5.10 m3/m) subsequent to the storm peak and during the storm decay; (b) progradation of the beach step to produce a new shore terrace; and (c) offshore migration of the two outer bars to provide the accommodation space necessary for the new bar. The primary transport mechanisms accounting for emergence of the new bar, its growth and migration were: (a) the mean cross-shore currents (undertow), which always transported suspended sediment offshore; and (b) the onshore transport of suspended sediment by incident gravity wave frequencies early in the storm and subsequently by infragravity waves (at the storm peak and the decay period). The longshore transport of sediment was significant in terms of the gross transport, although the net result was only a small transport to the south-west (historic littoral transport direction). It did not cause bar initiation, but it may have supplied some of the sediment for bar growth. The primary mechanism for bar initiation and growth was the cross-shore displacement of sediment by wave-driven (oscillatory) transport and cross-shore mean currents (undertow).

The equilibrium morphology of WC particles – A combined ab initio and experimental study

2011 ◽  
Vol 59 (9) ◽  
pp. 3748-3757 ◽  
Author(s):  
Yang Zhong ◽  
Hong Zhu ◽  
Leon L. Shaw ◽  
R. Ramprasad
Keyword(s):  
Experimental Study ◽  
Ab Initio ◽  
Equilibrium Morphology

Many-Scale Simulation of ABS/PC Blends for the Automotive Industry

2006 ◽  
Vol 51 ◽  
pp. 134-139
Author(s):  
Maurizio Fermeglia ◽  
Marco Ferrone ◽  
Paolo Cosoli ◽  
Maria Silvia Paneni ◽  
Roberta Venica ◽  
...  
Keyword(s):  
Automotive Industry ◽  
Mesoscale Model ◽  
Coefficient Of Thermal Expansion ◽  
Multiscale Simulation ◽  
Polymer Chains ◽  
Structure Property ◽  
Definition Of ◽  
Equilibrium Morphology ◽  
Post Industrial ◽  
Land Filling

Industrial scraps cannot be reused in an advantageous way, mainly because of their degradation. When possible, rejects are added to the virgin material for new molding, although the amount of recycled block copolymer cannot exceed 15% of moldable material to obtain good final performances. The remaining amount of scraps then follows three different routes: i) employment in very poor applications, ii) land filling, and iii) thermal treatment. For this reason, post industrial rejects constitute a major problem both from the standpoint of the European legislation and policy, and from the economic side where enterprises are concerned. In this work we have applied a multiscale simulation approach to study the nanostructured equilibrium morphology of blends consisting of mainly recycled block copolymers of special interest in the automotive industry. The main goal was the definition of the possible causes leading to incompatibility due to non virgin materials. In particular, starting from atomistic-based simulations we derived a procedure to 1) describe in appropriate fashion the polymer chains in terms of the relevant Gaussian models, and 2) determine the relevant Flory-Huggins interaction parameters. Finally, we coupled mesoscale model with finite elements codes to obtain a quantified structure-property relationship for mechanical modulus and coefficient of thermal expansion.

scholarly journals Equilibrium scour morphology downstream of rock sills under unsteady flow conditions

2018 ◽  
Vol 40 ◽  
pp. 03004 ◽  
Author(s):  
Stefano Pagliara ◽  
Michele Palermo
Keyword(s):  
Unsteady Flow ◽  
Experimental Tests ◽  
Peak Discharge ◽  
Flow Conditions ◽  
Different Shapes ◽  
Equilibrium Morphology ◽  
Inflow Discharge ◽  
Inflow Conditions ◽  
Scour Morphology ◽  
Correct Design

The present study aims to analyze the equilibrium scour morphology occurring downstream of rock-made sills with different shapes, under different inflow conditions. Namely, experimental tests were conducted under both steady and unsteady flow conditions. In this last case, the peak discharge was kept the same as the respective base tests performed for steady flow conditions. The scour evolution was carefully monitored, as well as the main characteristic lengths of the scour hole (e.g., maximum scour depth and axial length). The inflow discharge characteristics were varied, i.e., the maximum peak discharge was reached by adopting different hydrographs, in order to test their influence on the equilibrium morphology. Experimental results showed significant similitudes in terms of equilibrium scour morphology between steady and unsteady flow conditions when the hydrograph duration is enough long. The results of the present study can be useful for a correct design of such structure typology in usual applications.

scholarly journals Low Symmetry Polymorph of Hydroxyapatite. Theoretical Equilibrium Morphology of the Monoclinic Ca5(OH)(PO4)3

2014 ◽  
Vol 14 (6) ◽  
pp. 2846-2852 ◽  
Author(s):  
Dino Aquilano ◽  
Marco Bruno ◽  
Marco Rubbo ◽  
Francesco Roberto Massaro ◽  
Linda Pastero
Keyword(s):  
Equilibrium Morphology ◽  
Low Symmetry

Computer Simulation of the Equilibrium Morphology of Zirconia Nanocrystals

2015 ◽  
Vol 245 ◽  
pp. 3-7
Author(s):  
Andrey N. Chibisov
Keyword(s):  
Computer Simulation ◽  
Zirconium Oxide ◽  
Theoretical Calculations ◽  
Structure And Morphology ◽  
Cubic Phases ◽  
Equilibrium Morphology

The paper presents the theoretical calculations of the structure and morphology of ZrO2nanocrystals. The equilibrium morphology shapes of tetragonal and cubic nanocrystals were determined. It was shown that the equilibrium morphology was determined by an appropriate set of faces of tetragonal and cubic phases of zirconium oxide.

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