scholarly journals Mathematical Modelling of Water Absorption Kinetics Using Empirical and Phenomenological Models for Millets

2019 ◽  
Vol 8 (6) ◽  
pp. 1016-1021 ◽  
Keyword(s):  
Activation Energy ◽  
Water Absorption ◽  
Pearl Millet ◽  
Rate Constant ◽  
Finger Millet ◽  
Effective Diffusivity ◽  
Process Time ◽  
Absorption Kinetics ◽  
Experimental Conditions ◽  
Sigmoidal Model

Steeping is one of the major pre-treatment which can reduce anti-nutritional factors without losing dietary fibre and polyphenols unlike in dehulling. In the current study water absorption characteristics of pearl millet and finger millet during steeping at temperature 10°C, 20°C, 30°C, 40°C and 50°C were calculated. Two empirical and one phenomenological model were used to simulate water absorption kinetics. Both the Peleg model and Omoto model were found adequately capable to predict water uptake of pearl millet and finger millet under the designed experimental conditions with regression coefficient more than 0.96. Due to comparatively high variation in grain volume during the hydration process and longer process time, sigmoidal model cannot be utilized for calculation of effective diffusivity and activation energy. Peleg’s rate constant shows an inverse relationship with steeping temperature. The activation energy was calculated by substituting effective diffusivity with reciprocal of Peleg’s rate constant in Arrhenius equation and was found 25.97 kJ/mol and 32.36 kJ/mol respectively for pearl millet and finger millet.

scholarly journals Physical properties and water absorption kinetics of three varieties of Mucuna beans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ajibola B. Oyedeji ◽  
Olajide P. Sobukola ◽  
Ezekiel Green ◽  
Oluwafemi A. Adebo
Keyword(s):  
Physical Properties ◽  
Water Absorption ◽  
Rate Constant ◽  
Geometric Mean ◽  
Seed Mass ◽  
Activation Energies ◽  
Mucuna Pruriens ◽  
Absorption Kinetics ◽  
Kinetics Of ◽  
Soaking Temperature

AbstractThe physical properties and water absorption kinetics of three varieties of Mucuna beans (Mucuna pruriens, Mucuna rajada and Mucuna veracruz) were determined in this study. Physical properties including length, width, thickness, geometric mean diameter, sphericity, porosity, bulk density, area, volume and one thousand seed mass were calculated while hydration kinetics was studied by soaking Mucuna beans in water at 30 °C, 40 °C and 50 °C and measuring water uptake at 9 h interval. Peleg’s equation was used to model the hydration characteristics and Arrhenius equation was used to describe the effect of temperature on Peleg’s rate constant k1 and to obtain the activation energies for soaking. Significant variations were observed in almost all the physical properties of the different varieties, however, there were no significant differences (p < 0.05) in their thicknesses and bulk densities. The effectiveness of fit of Peleg’s model (R2) increased with increase in soaking temperature. Peleg’s rate constant k1 decreased with increase in soaking temperature while k2 increased with temperature increase. Activation energies of Mucuna pruriens, Mucuna rajada and Mucuna veracruz were 1613.24 kJ/mol, 747.95 kJ/mol and 2743.64 kJ/mol, respectively. This study provides useful information about the properties of three varieties of Mucuna beans that could be of importance to processors and engineers for process design and optimization.

Physical and nutritional qualities of extruded weaning foods containing sorghum, pearl millet, or finger millet blended with mung beans and nonfat dried milk

1996 ◽  
Vol 49 (3) ◽  
pp. 181-189 ◽  
Author(s):  
Nagappa G. Malleshi ◽  
Nirmala A. Hadimani ◽  
Rangaswami Chinnaswamy ◽  
Carol F. Klopfenstein
Keyword(s):  
Pearl Millet ◽  
Finger Millet ◽  
Weaning Foods ◽  
Nutritional Qualities

Theoretical analysis of water absorption kinetics of recycled aggregates immersed in water

2021 ◽  
Vol 302 ◽  
pp. 124156
Author(s):  
Kun Liang ◽  
Yingjie Hou ◽  
Jianchun Sun ◽  
Xiaoguang Li ◽  
Jiahong Bai ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Water Absorption ◽  
Recycled Aggregates ◽  
Absorption Kinetics ◽  
Kinetics Of

THE OXIDATION OF NITRITE AND IODATE IONS BY HYPOCHLORITE IONS

1961 ◽  
Vol 39 (8) ◽  
pp. 1645-1651 ◽  
Author(s):  
M. W. Lister ◽  
P. Rosenblum
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Rate Constant ◽  
Hypochlorous Acid ◽  
Slow Stage ◽  
Iodate Ions

The oxidation of nitrite ions and of iodate ions by hypochlorite ions in aqueous solution has been examined. The oxidation of nitrite is really a reaction of hypochlorous acid, with the slow stage HOCl + NO2− + H2O → H3O+ + Cl− + NO3−. The rate constant is given by log k = 7.36−6450/RT (time in minutes, and the activation energy in calories). The oxidation of iodate is chiefly a reaction of hypochlorite ions, probably ClO− + IO3− → Cl− + IO4−, although the rate is somewhat increased by a higher concentration of hydroxide ions. The rate constant is given by log k = 16.15−26,100/RT. These results are compared with other oxidations by hypochlorite ions, to see if any general trends are apparent.

Thermogravimetric devolatisation behavior of agricultural residue for generation of syngas

2021 ◽  
pp. 1-17
Author(s):  
Praveen Kumar ◽  
P.M.V. Subbarao ◽  
L.D. Kala ◽  
V.K. Vijay
Keyword(s):  
Activation Energy ◽  
Pearl Millet ◽  
Proximate Analysis ◽  
Thermochemical Conversion ◽  
Degradation Behavior ◽  
Ozawa Method ◽  
Thermogravimetric Method ◽  
Agricultural Residue ◽  
Tg Analysis ◽  
Tg And Dtg

Abstract The thermal degradation characteristics of eucalyptus, pearl millet cob, and corncob were investigated using non-isothermal thermogravimetric method. This investigation was performed with the objective of carrying out thermochemical conversion for obtaining syngas. TG and DTG analysis were carried out to understand thermal devolatisation behavior and estimation of various thermophysical properties of the biomasses. The degradation behavior was analysed in the light of lignocellulosic composition that was found to have definitive influence on degradation outcomes. TG analysis has been utilized to obtain proximate analysis of biomass. Activation energy using Flynn-Wall-Ozawa method have been estimated and found to be 201, 150 and 68 kJ mol−1 for eucalyptus, pearl millet cob, and corncob respectively. The TG analysis and activation energy together indicated that corncob is easiest for thermochemical conversion amongst the three biomasses. The TG curve also confirms the same.

scholarly journals Dynamics of platelet-activating-factor release and uptake in a human neutrophil suspension

1991 ◽  
Vol 278 (2) ◽  
pp. 453-459 ◽  
Author(s):  
M Cluzel ◽  
C A Rohde ◽  
D W MacGlashan ◽  
B J Undem ◽  
F H Chilton
Keyword(s):  
Cellular Uptake ◽  
Rate Constant ◽  
Exponential Function ◽  
Human Neutrophil ◽  
Platelet Activating Factor ◽  
Mathematical Functions ◽  
Experimental Conditions ◽  
Zero Baseline ◽  
Factor Release

The present study has examined the dynamics of platelet-activating-factor (PAF) synthesis, release and uptake in order to understand better the trafficking of PAF between cells and medium. Initial experiments indicated that the amount of PAF found on the outside of the cell remained constant well after the synthesis from a precursor had apparently stopped, and in spite of a continued capacity of the cell to take up and catabolize PAF. These results suggested that PAF produced and stored within the cell is eventually released to the outside of the cell at a rate proportional to that of cellular uptake. In order to estimate the amount of PAF released from the cell, the processes of PAF release and uptake were modelled using simple mathematical functions. It was found that, under the experimental conditions used in this study, the uptake of PAF could be expressed as an exponential function tending to a non-zero baseline. Utilizing this rate constant for the uptake of PAF with the amount of PAF outside the cell, the amount of total PAF released from the cell was estimated. Data from the model suggested PAF was released in amounts 10-fold higher than could actually be measured over 30 min. In fact, the model predicted more PAF could be released from the cell than is synthesized, suggesting that a portion of the PAF which is released is taken up and then released again to the outside of the cell. The potential for PAF and/or its intermediates to be recycled was verified by demonstrating that a large proportion of exogenously provided 1-alkyl-2-lyso-sn-glycero-3-phosphocholine is taken up by the neutrophil, converted into PAF and then released again by the cell. These results suggest that PAF trafficking between the cell and medium is complex and involves many processes, which include synthesis, release, uptake, catabolism and recycling.

scholarly journals Evaluation of Physico-Chemical, Nutritional, Mineral, Functional and Phytochemical Analysis in Functional and Nutraceutical Marked Cereals

2021 ◽  
pp. 114-124
Author(s):  
. Shilpa ◽  
Sangita Sood ◽  
Farhan Mohiuddin Bhat
Keyword(s):  
Protein Content ◽  
Pearl Millet ◽  
Finger Millet ◽  
Reducing Sugars ◽  
Neutral Detergent Fiber ◽  
Fibre Content ◽  
Phytochemical Analysis ◽  
Total Sugars ◽  
Physico Chemical ◽  
Insoluble Fibre

The present research was done to analyse the physico-chemical, Nutritional, Mineral, functional and phytochemical analysis in Functional cereals; oats, pearl millet, sorghum and finger millet. The protein content of the analyzed cereals varied from 7.45% to 14.69% with oats having higher concentration of protein content. The higher fibre content in oats accounted for its highest WAC while as the lowest fibre content in sorghum (2.35%) masked its WAC despite containing the highest carbohydrate content. Neutral detergent fiber that gives the measurement insoluble fibre was found highest in sorghum (11.29%) and lowest in pearl millet (5.56%). Total sugars comprising of reducing and non reducing sugars were found highest in pearl millet (2.88%) followed by sorghum (2.14%) and the least content was found in finger millet (1.69%). Oats were found to possess highest content of phosphorus (381.02mg/100g) and finger millet the lowest (8.21mg/100g). Resistant starch that is inaccessible to enzymes was found highest in oats (2.69g/100g) and lowest in sorghum (1.74g/100g).

scholarly journals Central Composite Design, Kinetic Model, Thermodynamics, and Chemical Composition of Pomelo (Citrus Maxima (Burm.) Merr.) Essential Oil Extraction by Steam Distillation

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2075
Author(s):  
Tan Phat Dao ◽  
Thanh Viet Nguyen ◽  
Thi Yen Nhi Tran ◽  
Xuan Tien Le ◽  
Ton Nu Thuy An ◽  
...  
Keyword(s):  
Activation Energy ◽  
Kinetic Model ◽  
Essential Oil ◽  
Rate Constant ◽  
Flow Rate ◽  
Steam Distillation ◽  
Extraction Process ◽  
Oil Extraction ◽  
Extraction Time ◽  
Pomelo Peel

Pomelo peel-derived essential oils have been gaining popularity due to greater demand for stress relief therapy or hair care therapy. In this study, we first performed optimization of parameters in the pomelo essential oil extraction process on a pilot scale to gain better insights for application in larger scale production. Then extraction kinetics, activation energy, thermodynamics, and essential oil quality during the extraction process were investigated during the steam distillation process. Three experimental conditions including material mass, steam flow rate, and extraction time were taken into consideration in response surface methodology (RSM) optimization. The optimal conditions were found as follows: sample weight of 422 g for one distillation batch, steam flow rate of 2.16 mL/min and extraction time of 106 min with the coefficient of determination R2 of 0.9812. The nonlinear kinetics demonstrated the compatibility of the kinetic model with simultaneous washing and unhindered diffusion with a washing rate constant of 0.1515 min−1 and a diffusion rate constant of 0.0236 min−1. The activation energy of the washing and diffusion process was 167.43 kJ.mol−1 and 96.25 kJ.mol−1, respectively. The thermodynamic value obtained at the ΔG° value was −35.02 kJ.mol−1. The quality of pomelo peel essential oil obtained by steam distillation was characterized by its high limonene content (96.996%), determined by GC-MS.

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