Condensed Matter

1508 Submissions

[4] viXra:1508.0208 [pdf] submitted on 2015-08-26 00:59:39

Analogous Viscosity Equations of Granular Powders Based on Eyring’s Rate Process Theory and Free Volume Concept

Authors: Tian Hao
Comments: Pages. published RSC Advances , 2015, 5, 95318-95333

Granular powders can be successfully treated with kinetic theory and statistical mechanics that are typically applicable to thermal systems, though the granular powders are athermal systems and the conventional environmental temperature is too weak to drive particles to move. Once the granular temperature is analogously defined in line with that in thermodynamics, viscosity concept of thermal systems is naturally borrowed to describe the flowability of granular powders in this article. Eyring’s rate process theory and free volume concept, which have been proved to be very powerful in dealing with many thermally activated phenomena in a wide variety of fields, are utilized to derive viscosity equations of granular powders under a simple shear. The obtained viscosity equations are examined only with empirical experimental observations in describing powder flowability, due to the lack of instruments and methodology for directly determining the viscosity of granular materials. The continuous shear thickening rather than the discontinuous shear thickening are predicted and found to be dependent on shear rate, the cohesive energy between particles, and the particle volume fraction, though the discontinuous shear thickening may still occur if certain conditions are met during shear, such as local particle volume fractions approach to the jamming point created by the shear induced inhomogeneity. A fundamental mechanism on how dry granular powders flow is proposed on the basis of what are demonstrated from the viscosity equations.The work presented in this article may lay a foundation to scale powder flowability in a more fundamental and consistent manner, at least providing an approach to consistently define the viscosity of granular powders. Since the same approaches are employed to derive the viscosity equations of granular powders as used to derive viscosity equations of liquids, colloidal suspensions, and polymeric materials, both athermal and thermal systems are thus unified with a single methodology.
Category: Condensed Matter

[3] viXra:1508.0182 [pdf] replaced on 2016-08-01 23:55:08

Defining Temperatures of Granular Powders Analogously with Thermodynamics to Understand the Jamming Phenomena

Authors: Tian Hao
Comments: 34 Pages.

For the purpose of applying laws or principles originated from thermal systems to granular athermal systems, we may need to properly define the critical “temperature” concept in granular powders. The conventional environmental temperature in thermal systems is too weak to drive movements of particles in granular powders and cannot function as a thermal energy indicator. For maintaining the same functionality as in thermal systems, the temperature in granular powders is defined analogously and uniformly in this article. The newly defined granular temperature is utilized to describe and explain one of the most important phenomena observed in granular powders, the jamming transition, by introducing jamming temperature and jamming volume fraction concepts. The predictions from the equations of the jamming volume fractions for several cases like granular powders under shear or vibration are in line with experimental observations and empirical solutions in powder handlings. The goal of this article is to establish similar concepts in granular powders, allowing granular powders to be described with common laws or principles we are familiar with in thermal systems. Our intention is to build a bridge between thermal systems and granular powders to account for many similarities already found between these two systems.
Category: Condensed Matter

[2] viXra:1508.0129 [pdf] submitted on 2015-08-17 06:01:13

London-Proca-Hirsch Equations for Electrodynamics of Superconductors on Cantor Sets

Authors: Victor Christianto
Comments: 11 Pages. This paper has been submitted to Prespacetime Journal for review. Your comments are welcome

In a recent paper published at Advances in High Energy Physics (AHEP) journal, Yang Zhao et al. derived Maxwell equations on Cantor sets from the local fractional vector calculus. It can be shown that Maxwell equations on Cantor sets in a fractal bounded domain give efficiency and accuracy for describing the fractal electric and magnetic fields. However, so far there is no derivation of equations for electrodynamics of superconductor on Cantor sets. Therefore, in this paper I present for the first time a derivation of London-Proca-Hirsch equations on Cantor sets. The name of London-Proca-Hirsch is proposed because the equations were based on modifying Proca and London-Hirsch’s theory of electrodynamics of superconductor. Considering that Proca equations may be used to explain electromagnetic effects in superconductor, I suggest that the proposed London-Proca-Hirsch equations on Cantor sets can describe electromagnetic of fractal superconductors. It is hoped that this paper may stimulate further investigations and experiments in particular for fractal superconductor. It may be expected to have some impact to fractal cosmology modeling too.
Category: Condensed Matter

[1] viXra:1508.0126 [pdf] submitted on 2015-08-16 12:33:45

Point Mass Model for Predicting 2-D Particles Motion Modes in Vertical Rotation Drum

Authors: Sparisoma Viridi, Siti Nurul Khotimah, Yulia Yopy Mardiansyah
Comments: 4 pages, 5 figures, conference paper

Motion modes of pseudo 2-d granular particles in vertical rotation drum is modeled using point mass motion considering only friction, normal, and gravitation forces. Two schemes in evaluating the forces are used, i.e. dynamics in 2-d linear and 1-d angular motions. Finite difference method implementing Euler scheme is used to solve the equation of motion.
Category: Condensed Matter