Choice Of Cell Size Research Articles

Evaluation of flotation circuits design using a novel approach

This paper presents a new approach for modelling and simulation of flotation circuits, which addresses the potential to increase metallurgical performance, selecting the best choice of cell size, number of cells per bank, cell design and operating conditions. For this purpose, a flotation simulator was built and calibrated using data from industrial sampling campaigns carried out in Chilean concentrators, using modern and large mechanical flotation cells.The simulator allowed for evaluating and comparing the metallurgical performance of different flotation circuits. For this purpose, alternative scenarios were analysed for a selected industrial circuit, where different cells arrangement (number and size of cells), launder designs (represented by the mean froth transport distance) and operating conditions (pulp residence time and froth depth) were evaluated.This new approach showed to be a useful and practical tool to evaluate metallurgical performance in large industrial flotation banks, being able to show the effect of different flotation process characteristics such as froth transport distances and operating conditions.

Thin-Wire Model Using Subcellular Extensions in the Finite-Difference Time-Domain Analysis of Thin and Lossy Insulated Cylindrical Structures in Lossy Media

Recently, a subcellular thin-wire model for the finite-difference time-domain (FDTD) simulation of resistively coated cylinders with lossless insulating and surrounding media was presented. In this paper, it is shown that this model can be extended to lossy cases. The material discontinuity between lossy insulating and surrounding media is corrected as the time-domain boundary condition. The convolution term of the boundary condition is solved by employing a recursive technique. Applying the contour-path integration to the FDTD unit cells around the wire, one may find the coarse-grid-based equation with the correction term and factors for the material discontinuity and the quasi-static field behavior around the wire. In the 2-D cylindrical coordinates with rotational symmetry, the validity of the proposed model is confirmed by an impedance analysis of insulated and resistive antennas according to the electrical properties of insulating and surrounding media, as well as the choice of cell size.

The Treatment of Thin Wires in the FDTD Method Using a Weighted Residuals Approach

In this contribution, the problem of accurately representing thin wires within the finite-difference time-domain (FDTD) mesh is addressed by means of a method based on the weighted residual (WR) interpretation of the FDTD algorithm. Results for wire dipoles and wire transmission lines, obtained using the proposed method, are presented and compared to those obtained using existing techniques. It is shown that the proposed method yields results which are more accurate and are less dependent on the choice of cell size than other approaches and, in addition, lends itself well to being extended for more complicated structures. Details of the calculation of the update equations are given.

2D ray-tracing model for indoor radio propagation at millimetre frequencies, and the study of diversity techniques

A deterministic approach to model radio propagation channels in complex environments and use the model to study diversity techniques is described. The simulation is based on geometric optics and uses ray-tracing techniques. The effects of all rectangular obstacles are considered by the model. Both reflection and refraction effects are taken into account. Simulation results are presented and the reliability of these results is examined by comparing them with those obtained from measurements at 60 GHz. Also it is shown that it is possible to minimise the simulation time of the model by an appropriate choice of cell size. The model is seen to be able to investigate delay spread in an environment in considerable detail. The performance of space, frequency and polarisation diversity is investigated by use of the model. The results show that space diversity is better than polarisation or frequency diversity in the environments examined.

Catchment infiltration II: Contributing areas

This study considers two issues of interest to the hydrologic and geographical information systems community. One deals with identifying the spatial distribution of infiltration and runoff contributing areas. The other addresses process modelling within a GIS framework. The study operates on the premise that partitioning of precipitation into runoff or infiltration depends on rainfall intensity and on soil properties. The problem is that neither local rainfall intensity, nor soil properties such as infiltration capacity and macroporosity are known well enough for all points of a catchment and need to be estimated. We infer local intensity from the interpolated distribution of cumulated rain depths over the catchment and record duration at the official met site. Measured values of sorptivity and hydraulic conductivity define infiltration. Negative head infiltration describes macroporosity. To scale‐up measured point values to larger areas and to model infiltration and macropore continuity at a catchment scale we use geostatistical kriging and conditional simulation together with standard GIS techniques of overlay manipulation. Results delineate areas contributing to runoff and infiltration and relate them to macroporosity. By intersecting overlays of precipitation with those of infiltration we create alternate GIS masks targeting specific portions of the watershed as either runoff or infiltration contributing zones. Choice of cell size and time interval define the scales of averaging for the application. Kriged surfaces illustrate the distribution of catchment infiltration, while conditional simulation provides a mechanism to define model uncertainty.

Estimation of density functionals

Given a sequence of independent random variables with densityf we estimate quantities θ of the form θ=∫ φ(f(x))dx, φ a known function, by inserting histograms and kernel density estimators for the unknownf. We obtain conditions for consistency and asymptotic normality and discuss the choice of cell size and bandwidth.

The use and abuse of image analysis in geophysical potential field interpretation

Images of geophysical potential field data are becoming more common as a result of the increased availability of image analysis systems. These data are processed using techniques originally developed for remotely sensed satellite imagery. In general, geophysicists are not familiar with such techniques and may apply them without due consideration. This can lead to abuses of the geophysical data and reduce the validity of the interpretation. This paper describes some critical processes which can introduce errors to the data. The production of a regular grid from scattered data is fundamental to image processing. The choice of cell size is paramount and must balance the spatial distribution of the data. The necessary scaling of data from real values into a byte format for display purposes can result in small anomalies being masked. Contrast stretching of grey level images is often applied but can alter the shape of anomalies by varying degrees and should be avoided. Filters are often used to produce shaded relief images but without due regard to their frequency response and the effect on images expanded to fill the display space. The generation of spurious numerical artefacts can be reduced by ensuring that the filter is applied at real precision to the original data grid. The resultant images can then be processed for display. The use of image analysis systems for data integration requires careful consideration of the sampling strategy and information content of each dataset. It is proposed that such procedures are more appropriately conducted on a geographic information system.

Choice of cell size in the cell theory of hydrate phase gas-water interactions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChoice of cell size in the cell theory of hydrate phase gas-water interactionsV. T. John and G. D. HolderCite this: J. Phys. Chem. 1981, 85, 13, 1811–1814Publication Date (Print):June 1, 1981Publication History Published online1 May 2002Published inissue 1 June 1981https://doi.org/10.1021/j150613a010RIGHTS & PERMISSIONSArticle Views155Altmetric-Citations37LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (492 KB) Get e-Alerts