scholarly journals Mathematical Modeling of the Bulk Density Property of Knitted Fabrics

Engineering ◽  
2022 ◽  
Vol 14 (01) ◽  
pp. 33-42
Author(s):  
Iroda Ibrohimovna Kamalova ◽  
Baxtiyor Farruxovich Mirusmanov ◽  
Juramirza Abdiramatovich Kayumov ◽  
Axtam Akramovich Qosimov ◽  
Muborak Nosir Qizi Yusupova
Keyword(s):  
Mathematical Modeling ◽  
Bulk Density ◽  
Density Property ◽  
Knitted Fabrics

scholarly journals Mathematical modeling of the drying of orange bagasse associating the convective method and infrared radiation

2015 ◽  
Vol 19 (12) ◽  
pp. 1178-1184 ◽  
Author(s):  
Carolina M. Sánchez-Sáenz ◽  
Vânia R. G. Nascimento ◽  
João D. Biagi ◽  
Rafael A. de Oliveira
Keyword(s):  
Mathematical Modeling ◽  
Activation Energy ◽  
Moisture Content ◽  
Bulk Density ◽  
Water Activity ◽  
Infrared Radiation ◽  
Arrhenius Equation ◽  
Drying Process ◽  
Drying Conditions ◽  
Central Composite

ABSTRACT Mathematical modeling enables dimensioning of dryers, optimization of drying conditions and the evaluation of process performance. The aim of this research was to describe the behavior of orange bagasse drying using Page's and Fick's second law models, and to assess activation energy (using Arrhenius equation), moisture content, water activity and bulk density of product at the end of the process. The drying experimental assays were performed in 2011 with convective air temperature between 36 and 64 ºC and infrared radiation application time in the range from 23 to 277 s in accordance with the experimental central composite rotatable design. Analysis of variance and F-test were applied to results. At the end of the drying process, moisture content was about 0.09 to 0.87 db and water activity was between 0.25 and 0.87. Bulk density did not vary under studied conditions. Empirical Page's model demonstrated better representation of experimental data than the Fick's model for spheres. Activation energy values were about 18.491; 14.975 and 11.421 kJ mol-1 for infrared application times of 60; 150 e 244 s, respectively.

Cerebral Blood Circulation in Premature Infants by Means of Mathematical Modeling

2015 ◽  
Vol 46 (S 01) ◽  
Author(s):  
R. Lampe ◽  
N. Botkin ◽  
V. Turova ◽  
T. Blumenstein ◽  
A. Alves-Pinto
Keyword(s):  
Mathematical Modeling ◽  
Premature Infants ◽  
Blood Circulation ◽  
Cerebral Blood Circulation

A novel approach to white liquor control in a continuous digester using the Box-Jenkins methodology to predict chip bulk density

TAPPI Journal ◽  
2015 ◽  
Vol 14 (6) ◽  
pp. 395-402
Author(s):  
FLÁVIO MARCELO CORREIA ◽  
JOSÉ VICENTE HALLAK D’ANGELO ◽  
SUELI APARECIDA MINGOTI
Keyword(s):  
Bulk Density ◽  
Moving Average ◽  
Pulp Mill ◽  
Statistical Decision ◽  
White Liquor ◽  
Novel Approach ◽  
Cooking Process ◽  
Eucalyptus Kraft Pulp ◽  
Relevant Variables ◽  
Kraft Cooking

Alkali charge is one of the most relevant variables in the continuous kraft cooking process. The white liquor mass flow rate can be determined by analyzing the chip bulk density fed to the process. At the mills, the total time for this analysis usually is greater than the residence time in the digester. This can lead to an increasing error in the mass of white liquor added relative to the specified alkali charge. This paper proposes a new approach using the Box-Jenkins methodology to develop a dynamic model for predicting chip bulk density. Industrial data were gathered on 1948 observations over a period of 12 months from a Kamyr continuous digester at a bleached eucalyptus kraft pulp mill in Brazil. Autoregressive integrated moving average (ARIMA) models were evaluated according to different statistical decision criteria, leading to the choice of ARIMA (2,0,2) as the best forecasting model, which was validated against a new dataset gathered during 2 months of operations. A combination of predictors has shown more accurate results compared to those obtained by laboratory analysis, allowing a reduction of around 25% of the chip bulk density error to the alkali addition amount.

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