Internal Specification of Coarse Structure

1996 ◽  
pp. 73-112
Author(s):  
Ulrich Golze
Keyword(s):  
Coarse Structure

scholarly journals Coarse cohomology with twisted coefficients

2020 ◽  
Vol 70 (6) ◽  
pp. 1413-1444
Author(s):  
Elisa Hartmann
Keyword(s):  
Sheaf Cohomology ◽  
Grothendieck Topology ◽  
Coarse Structure ◽  
Relative Cohomology ◽  
Number Of Ends ◽  
Constant Coefficients ◽  
Coarse Space ◽  
Grothendieck Topologies

AbstractTo a coarse structure we associate a Grothendieck topology which is determined by coarse covers. A coarse map between coarse spaces gives rise to a morphism of Grothendieck topologies. This way we define sheaves and sheaf cohomology on coarse spaces. We obtain that sheaf cohomology is a functor on the coarse category: if two coarse maps are close they induce the same map in cohomology. There is a coarse version of a Mayer-Vietoris sequence and for every inclusion of coarse spaces there is a coarse version of relative cohomology. Cohomology with constant coefficients can be computed using the number of ends of a coarse space.

scholarly journals Extremal balleans

2019 ◽  
Vol 20 (1) ◽  
pp. 297
Author(s):  
Igor Protasov
Keyword(s):  
Coarse Structure ◽  
Unbounded Subset ◽  
Coarse Space ◽  
Extremal Properties

<p>A ballean (or coarse space) is a set endowed with a coarse structure. A ballean X is called normal if any two asymptotically disjoint subsets of X are asymptotically separated.  We say that a ballean X is ultra-normal (extremely normal) if any two unbounded subsets of X are not asymptotically disjoint (every unbounded subset of X is large).   Every maximal ballean is extremely normal and every extremely normal ballean is ultranormal, but the converse statements do not hold.   A normal ballean is ultranormal if and only if the Higson′s corona of X is a singleton.   A discrete ballean X is ultranormal if and only if X is maximal.  We construct a series of concrete balleans with extremal properties.</p>

scholarly journals Balleans, hyperballeans and ideals

2019 ◽  
Vol 20 (2) ◽  
pp. 431 ◽  
Author(s):  
Dikran Dikranjan ◽  
Igor Protasov ◽  
Ksenia Protasova ◽  
Nicolò Zava
Keyword(s):  
Boolean Algebra ◽  
Topological Space ◽  
Connected Components ◽  
Coarse Structure

<p>A ballean B (or a coarse structure) on a set X is a family of subsets of X called balls (or entourages of the diagonal in X × X) dened in such a way that B can be considered as the asymptotic counterpart of a uniform topological space. The aim of this paper is to study two concrete balleans dened by the ideals in the Boolean algebra of all subsets of X and their hyperballeans, with particular emphasis on their connectedness structure, more specically the number of their connected components.</p>

A model for the coarse structure of paramyosin filaments

1970 ◽  
Vol 53 (2) ◽  
pp. 181-203 ◽  
Author(s):  
A. Elliott ◽  
J. Lowy
Keyword(s):  
Coarse Structure

Structure of the Band Spectrum of CuCl Molecule. I. Additional Knowledge in the Coarse Structure

1961 ◽  
Vol 35 (3) ◽  
pp. 776-787 ◽  
Author(s):  
P. Ramakoteswara Rao ◽  
J. K. Brody
Keyword(s):  
Band Spectrum ◽  
Coarse Structure

Near Bandgap Optical Absorption Measurements on InGaAs/InP Strained Layers with Coarse Structure

1992 ◽  
Vol 263 ◽  
Author(s):  
P. Roura ◽  
J. Bosch ◽  
A. Cornet ◽  
F. Peiroi ◽  
J.R. Morante ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Absorption ◽  
Heavy Hole ◽  
Light Hole ◽  
Absorption Analysis ◽  
Strained Layers ◽  
Coarse Structure ◽  
Transmission Electron ◽  
Absorption Measurements

ABSTRACTOptical absorption measurements have been carried out on compressive InGaAs/FInP strained layers. It is shown that thoptical absorption analysis is a powerful technique in order to study the inhomogeneities of strained layers. The energetic dispersion of the heavy hole relative to the light hole subband σHH/σLH is related with the presence of the coarse structure seen in Transmission Electron Microscopy observations.

scholarly journals Phase Structure and Cyclic Deformation in Eutectic Tin-Lead Alloy: A Numerical Analysis

2000 ◽  
Vol 123 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Y.-L. Shen ◽  
W. Li ◽  
H. E. Fang
Keyword(s):  
Cyclic Deformation ◽  
Pure Shear ◽  
Micromechanical Modeling ◽  
Eutectic System ◽  
Lead Alloy ◽  
Two Phase ◽  
Damage Initiation ◽  
Coarse Structure ◽  
Numerical Result ◽  
Before And After

This study is devoted to providing a mechanistic rationale of coarsening induced failure in solder alloys during thermomechanical fatigue. Micromechanical modeling of cyclic deformation of eutectic tin-lead alloy was undertaken using the finite element method. The models consist of regularly arranged tin-rich and lead-rich phases, simulating the lamellar array and colony structure in a typical eutectic system. A fine structure and a coarse structure, bearing the same phase fraction but different in the aspect ratio of each lead-rich layer and in the number of lead-rich layers in each colony, are utilized for representing the microstructure before and after coarsening, respectively. Both phases are treated as elastic–plastic solids with their respective properties. For simplicity the creep effect is ignored without compromising the main objective of this study. Cyclic loading under pure shear and uniaxial conditions is modeled. It is found that both the fine and coarse structures exhibit essentially the same macroscopic stress–strain response. The coarse structure, however, shows a greater maximum effective plastic strain on a local scale throughout the deformation. The numerical result implies that, in a solder joint, a locally coarsened region may not be mechanically weaker than its surrounding, but it is subject to early damage initiation due to accumulated plasticity. Other implications regarding solder alloy failure and micromechanical modeling of two-phase materials are discussed.

Abrasive-Assisted Electroforming of Nickel on Translational Cathode

2013 ◽  
Vol 770 ◽  
pp. 145-149 ◽  
Author(s):  
Zeng Wei Zhu ◽  
Dong Wang ◽  
Jian Hua Ren
Keyword(s):  
Mechanical Properties ◽  
Current Density ◽  
Traditional Method ◽  
Coarse Structure ◽  
Electroforming Process ◽  
Nickel Deposits ◽  
Nickel Electroforming

Spherical abrasives were employed to polish the growing deposited layer during nickel electroforming process. On a translational flat cathode, nickel deposits with distinct polishing mark were obtained. It was found that the abrasive polishing can help to improve the microstructure and increase the mechanical properties of the nickel deposits. Compared with the deposits prepared with traditional method, the microstructure became more homogeneous and the microhardness increased nearly two times. The increase of current density led to coarse structure and lower microhardness.

scholarly journals The record of the diatom Cymbella australica (A.Schmidt) Cl. in water bodies of Kyiv (Ukraine)

Algologia ◽  
2021 ◽  
Vol 31 (3) ◽  
pp. 271-278
Author(s):  
G.G. Lilitska ◽  
Keyword(s):  
Cell Size ◽  
Water Bodies ◽  
Coarse Structure

The diatom Cymbella australica was found in some water bodies in research of the algaeflora of Kyiv. The Kyiv population of this species had some discrepancies with the diagnosis (Krammer, 2002) of cell size and coarse structure, which brought it closer to C. tumida (Bréb.) Van Heurck. However, the outlines of the sash clearly separated the Kyiv population of C. australica from C. tumida. It is proposed to expand the diagnosis of C. australica and to consider cell outlines as the only discriminatory feature between C. australica and C. tumida.

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