the simulation of distillation columns is an essential step in design, optimization, and rating. in this paper, a new procedure has been proposed for the initial estimation of column profiles based on modified kremser’s group method for simple and/or complex columns. the effect of this initialization algorithm on simulation procedure has been studied through two examples. the results show signi...

in this paper, a cfd model of syngas flow in slurry bubble column was developed. the model is based on an eulerian-eulerian approach and includes three phases: slurry of solid particles suspended in paraffin oil and syngas bubbles. numerical calculations carried out for catalyst particles, bubble coalescence and breakup included bubble-fluid drag force and interfacial area effects. also, the ef...

let a and b be n × m matrices. the matrix b is said to be g-row majorized (respectively g-column majorized) by a, if every row (respectively column) of b, is g-majorized by the corresponding row (respectively column) of a. in this paper all kinds of g-majorization are studied on mn,m, and the possible structure of their linear preservers will be found. also all linear operators t : mn,m ---> mn...

Commodity hardware is available in configurations with huge amounts of main memory and it is viable to keep large databases of enterprises in the RAM of one or a few machines. Additionally, a reunification of transactional and analytical systems has been proposed to enable operational reporting on the most recent data. In-memory column stores appeared in academia and industry as a solution to h...

Cost models are an essential part of database systems, as they are the basis of query performance optimization. Based on predictions made by cost models, the fastest query execution plan can be chosen and executed or algorithms can be tuned and optimized. In-memory databases shift the focus from disk to main memory accesses and CPU costs, compared to disk based systems where input and output co...

Distillation columns are complex processes for modeling and controlling. These columns are significant parts of most chemical industries for separation of components. Control of this process is essential for achieving certain purity for products with a minimum cost. However, nonlinearities, multivariable interaction, non-stationary behavior and severity of disturbances inside the column made th...

we first describe how to “fuzzify” the estimated binary columns to create a [0,1]-valued column. werefer to this [0,1] -valued column as the soft segmentation column of the noisy spectrogram column.similarly to the collection of soft segmentation columns as the soft segmentation image, or simply asthe soft segmentation. the band-dependent posterior probability that the hard segmentation columnv...

heavy metals due to their non biodegradability properties and can accumulate in living tissues, thus becoming concentrated throughout the food chain and can be readily absorbed into the human body. among them manganese was examined in this study as a pollutant. the aim of this study is the manganese removal from aqueous solution using a windy sand fixed bed column of sistan plain. flow rate, in...

We first describe how to “fuzzify” the estimated binary columns to create a [0,1]-valued column. Werefer to this [0,1] -valued column as the soft segmentation column of the noisy spectrogram column.Similarly to the collection of soft segmentation columns as the soft segmentation image, or simply asthe soft segmentation. The band-dependent posterior probability that the hard segmentation columnv...

The use of composite materials is an effective technique to enhance the capacity of reinforced concrete columns subjected to the seismic loading due to their high tensile strength. In this paper, numerical models are developed in order to predict the experimental behavior of square reinforced concrete columns strengthened by glass fiber reinforced polymer and steel bars and unstrengthened colum...