Discrete Element Analysis

Liu, Q.S. et al. 2011. Discrete element analysis of effect of stress on equivalent permeability of fractured rock mass. Chinese Journal of Rock Mechanics and Engineering 30(01) 176-183. 

Elemental Speciation - New Approaches for Trace Element Analysis Discrete Sample Introduction Techniques for Inductively Coupled Plasma Mass Spectrometry... 

Therefore, the mesostructured tungsten sulfides MTS-W, MTS-M and MTS-C must consist of organic templates intercalated between condensed inorganic walls made up of layered WS2 and chain-like WS3. On the other hand. The product prepared at room temperature in aqueous solution (i.e. MTS-RT) mainly contains organic templates and discrete WS42 clusters. It should be noted that WS3is X-ray amorphous. Its presence in the mesostructured materials was further confirmed by the elemental analysis results of the products (Table 1). 

There have been some attempts to overcome the analysis of compaction problems, mostly by introducing numerical modeling approaches. The modeling approaches often used in compaction analysis are (a) phenomenological continuum models, (b) micromechanically based continuum models, and (c) discrete-element models. The parameters that should be analyzed when tableting is under development are as follows ... 

We present the major results established in the description of crazing and the recent developments in this field. Crazing has been investigated within continuum or discrete approaches (e.g., spring networks or molecular dynamics calculations to model the craze fibrils), which have provided phenomenological or physically based descriptions. Both are included in the presentation of the crazing process, since they will provide the basis for the recent cohesive surface model used to represent crazing in a finite element analysis [20-22],... 

Analysis schemes developed for identifying clay minerals in the TEM based on EDS spectra (e.g., Murdoch et al.100) are inappropriate for colloidal samples dispersed on polycarbonate filters due to complications associated with the various sample-beam-substrate interactions that differ dramatically from that of ideal samples or standards with smooth polished surfaces.94 96 101 102 Correction procedures that account for the influence of particle size and morphology on x-ray spectra have been widely available for some time,101102 but these techniques have not been applied to the analysis of environmental particulates. To overcome the limitation of quantitative elemental analysis, some research groups have compared the x-ray spectra for sample colloids to the spectra for various minerals of similar size and composition under the same instrumental and sample preparation conditions to calibrate instrumental response.7 24 93 Noting the resolution problems associated with SEM analysis of submicron colloids, several research groups have chosen TEM as the primary discrete particle analysis technique,21 52 103 104 or have combined TEM analysis techniques, such as electron diffraction and x-ray microanalysis, to confirm conclusions drawn from SEM surveys.7,93 105... 

The analysis of archaeological bone presents several problems which are encountered to a much lesser degree in the analysis of inorganic substances where often a discrete source is involved and where the matrix is not as open to contamination by the depositional environment. Nevertheless, bone is one of the most commonly found archaeological materials, and any inferences made from its trace elemental composition would certainly be useful. We relate herein our experiences with the trace element analysis of archaeological bone, the problems encountered in these analyses, and some of the conclusions that we have reached as the result of our measurements. 

Finite element analysis was carried out to study the validity of the evaluation formula derived in the previous section. The MMD specimen was discretized with 2-dimensional plane strain or 3-dimensional solid elements according to the purpose of the analysis, as shown in Fig. 4. The finite element code, MARC 2001, was used for the analysis. 

Elemental analysis mapping of discrete particles Trace elemental levels isotopic-ratio determinations (i.e. i)... 

Gethin DT, Ransing RS, Lewis RW, et al. Numerical comparison of a deformable discrete element model and an equivalent continuum analysis for the compaction of ductile porous material. Comput Struct 2001 79 1287-1294. 

The disperse phase is constituted by discrete elements. One of the main assumptions of our analysis is that the characteristic length scales of the elements are smaller than the characteristic length scale of the variation of properties of interest (i.e. chemical species concentration, temperature, continuous phase velocities). If this hypothesis holds, the particulate system can be described by a continuum or mean-field theory. Each element of the disperse phase is generally identified by a number of properties known as coordinates. Two elements are identical if they have identical values for their coordinates, otherwise elements are indistinguishable. Usually coordinates are classified as internal and external. External coordinates are spatial coordinates in fact, the position of the elements in physical space is not an internal property of the elements. Internal coordinates refer to more intimate properties of the elements such as their momenta (or velocities), their enthalpy... 

Finite element analysis involves the discretization of a geometry into smaller areas (in two-dimensional problems) or smaller volumes (in three-dimensional analyses). This discretization permits the solution of complicated boundary-value problems involving... 

Hybrid model of Discrete Fracture Network (DFN) and Discrete Element Method (DEM) for coupled stress-flow analysis of rock slope stability (Wang, 2000) ... 

Wang H. 2000. Hybrid model of discrete fracture network and discrete element method for rock slope stability analysis. J. of Hydrogeology Engineering Geology, Vol. 2, pp. 30-34. 

State that we cannot know all factors and processes that influence the values we observe for a certain wetland biogeochemical property. Simple statistical methods as a continuous response (regression analysis) or as a set of responses to discrete factors (analysis of variance, ANOVA) have been used extensively in wetland research, in order to relate elements in biogeochemical processes or determine the extent to which a particular factor may influence a process. 

This article, based on analysis of unloading of marble, with combinations of several methods, such as energy, acoustic emission and discrete element, comes to the following conclusions ... 

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