Size-dependent elastic moduli of platelike nanomaterials

2003 ◽  
Vol 93 (2) ◽  
pp. 1212-1218 ◽  
Author(s):  
C. T. Sun ◽  
Haitao Zhang
Keyword(s):  
Elastic Moduli ◽  
Size Dependent

scholarly journals THE SURFACE- AND SIZE-DEPENDENT ELASTIC MODULI OF NANOSTRUCTURES

2007 ◽  
Vol 14 (04) ◽  
pp. 667-670 ◽  
Author(s):  
JIAN-GANG GUO ◽  
YA-PU ZHAO
Keyword(s):  
Theoretical Model ◽  
Surface Energy ◽  
Continuum Model ◽  
Elastic Moduli ◽  
Three Dimensional ◽  
Surface Effects ◽  
Surface Relaxation ◽  
Size Dependent ◽  
Analytical Expressions

A theoretical model is presented to investigate the size-dependent elastic moduli of nanostructures with the effects of the surface relaxation surface energy taken into consideration. At nanoscale, due to the large ratios of the surface-to-volume, the surface effects, which include surface relaxation surface energy, etc., can play important roles. Thus, the elastic moduli of nanostructures become surface- and size-dependent. In the research, the three-dimensional continuum model of the nanofilm with the surface effects is investigated. The analytical expressions of five nonzero elastic moduli of the nanofilm are derived, and then the dependence of the elastic moduli is discussed on the surface effects and the characteristic dimensions of nanofilms.

Size-Dependent Elastic Moduli of FCC Crystal Nanofilms

2006 ◽  
Vol 924 ◽  
Author(s):  
Shih-Hsiang Chang ◽  
I-Ling Chang
Keyword(s):  
Young’S Modulus ◽  
Size Effects ◽  
Continuum Model ◽  
Elastic Moduli ◽  
Young's Modulus ◽  
Current Model ◽  
Continuum Theory ◽  
Thickness Direction ◽  
Size Dependent ◽  
Discrete Nature

ABSTRACTA semi-continuum model is constructed to study the size effects on the mechanical properties of face-cubic-center crystal structure nanofilms. Unlike the classical continuum theory, the current model directly takes the discrete nature in the thickness direction into consideration. In-plane and out-plane Poisson's ratios as well as in-plane Young's modulus are investigated with this model. It is found that the values of the Young's modulus and Poisson's ratio depend on the film thickness and approach the respective bulk values asymptotically.

Size-dependent elastic moduli and vibrational properties of fivefold twinned copper nanowires

2014 ◽  
Vol 25 (31) ◽  
pp. 315701 ◽  
Author(s):  
Y G Zheng ◽  
Y T Zhao ◽  
H F Ye ◽  
H W Zhang
Keyword(s):  
Elastic Moduli ◽  
Vibrational Properties ◽  
Copper Nanowires ◽  
Size Dependent

Numerical Evaluation of the Size-Dependent Elastic Properties of Cellular Polymers

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Gurudutt Chandrashekar ◽  
Chung-Souk Han
Keyword(s):  
Relative Density ◽  
Cell Size ◽  
Elastic Properties ◽  
Numerical Evaluation ◽  
Elastic Moduli ◽  
Size Dependence ◽  
Experimental Studies ◽  
Length Scale ◽  
Cellular Solid ◽  
Size Dependent

Several experimental studies have revealed that the size-dependent deformation in polymers at nano- to micro-meter length scales is significantly associated with elastic deformation. Such size-dependent deformation in polymers is expected to affect the in-plane macroscopic elastic properties of cellular polymers with micrometer-sized cells. A finite element (FE) formulation of a higher-order elasticity theory is applied to evaluate the in-plane macroscopic elastic properties of different polymer cellular geometries by varying the cell size from the macroscopic to micron length scale. For a given relative density of the cellular solid, a reduction in the cell size from the macroscopic to micron length scale resulted in geometry-specific variations in the in-plane macroscopic elastic moduli and Poisson's ratios. Furthermore, an increase in the relative density for a given cell size revealed variations in the size dependence of the elastic properties. The size dependence of elastic properties is interpreted based on the influence of rotation gradients with varying cell size of the cellular solid. Also, the evaluated size-dependent elastic properties are compared with the available analytical solutions from the literature.

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

Spindle scaling mechanisms

2020 ◽  
Vol 64 (2) ◽  
pp. 383-396
Author(s):  
Lara K. Krüger ◽  
Phong T. Tran
Keyword(s):  
Cell Size ◽  
Spindle Assembly ◽  
Dependent Manner ◽  
Post Translational Modification ◽  
Size Dependent ◽  
A Cell ◽  
Chromosome Separation ◽  
Spindle Elongation ◽  
Protein Gradients ◽  
Spindle Structure

Abstract The mitotic spindle robustly scales with cell size in a plethora of different organisms. During development and throughout evolution, the spindle adjusts to cell size in metazoans and yeast in order to ensure faithful chromosome separation. Spindle adjustment to cell size occurs by the scaling of spindle length, spindle shape and the velocity of spindle assembly and elongation. Different mechanisms, depending on spindle structure and organism, account for these scaling relationships. The limited availability of critical spindle components, protein gradients, sequestration of spindle components, or post-translational modification and differential expression levels have been implicated in the regulation of spindle length and the spindle assembly/elongation velocity in a cell size-dependent manner. In this review, we will discuss the phenomenon and mechanisms of spindle length, spindle shape and spindle elongation velocity scaling with cell size.

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