scholarly journals Mathematical modeling of the foam-mat drying curves of guava pulp

2017 ◽  
Vol 21 (10) ◽  
pp. 721-725 ◽  
Author(s):  
Roberta M. G. Maciel ◽  
Marcos R. A. Afonso ◽  
José M. C. da Costa ◽  
Leandro S. Severo ◽  
Natália D. de Lima
Keyword(s):  
Experimental Data ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Albumin Concentration ◽  
Mean Square ◽  
Liquid Food ◽  
Chi Square ◽  
Foaming Agent ◽  
Chi Square Test ◽  
Drying Curves

ABSTRACT In foam-mat drying, the liquid food is foamed by the addition of a foaming agent, for example, albumin. The aim of this study was to evaluate the adjustment of mathematical models to foam mat drying curves of guava pulp. The fits were evaluated using samples with 4 and 8% albumin (m m-1) and drying temperatures of 75, 80 and 85 °C. The samples were placed on aluminum trays. Drying was carried out in a tray dryer. The Lewis, Page, Midilli and Logarithmic models were fitted to the experimental data and evaluated based on the coefficient of determination (R2), root-mean-square error (RMSE) and chi-square test. All models fitted well to experimental data and Midilli was the best. Albumin concentration and temperature influenced the drying rate; the lowest drying times occurred for the highest albumin concentration and highest drying temperature.

scholarly journals Drying kinetics of crushed mass of ‘jambu’: Effective diffusivity and activation energy

2018 ◽  
Vol 22 (7) ◽  
pp. 499-505 ◽  
Author(s):  
Francileni P. Gomes ◽  
Resende Osvaldo ◽  
Elisabete P. Sousa ◽  
Daneil E. C. de Oliveira ◽  
Francisco R. de Araújo Neto
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Agricultural Research ◽  
Effective Diffusion ◽  
Effective Diffusivity ◽  
Information Criterion ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Chi Square ◽  
Chi Square Test

ABSTRACT The aim of this paper was to analyze the drying kinetics, test the Akaike information criterion (AIC) and Schwarz’s Bayesian information criterion (BIC) in the selection of models, determine the effective diffusivity and activation energy of the crushed mass of ‘jambu’ leaves for different conditions of temperature and layer thicknesses. The experiment was carried out at the Food Laboratory of the Brazilian Agricultural Research Corporation (Embrapa) in Macapá-AP. Drying was carried out in air circulation oven with speed of 1.0 m s-1 at various temperatures (60, 70 and 80 ºC) and layer thicknesses (0.005 and 0.010 m). The experimental data were fitted to 11 mathematical models. Coefficient of determination (R2), mean relative error (P), mean estimated error (SE), Chi-square test (χ2), AIC and BIC were the selection criteria for the models. For the effective diffusivity, the Fick’s diffusion model was used considering the flat plate geometry. It was found that Midilli and Logarithmic models showed the best fit to the experimental data of drying kinetics. Effective diffusion coefficient increases with increment in the thickness of the material and with the temperature elevation. Activation energy of the material was of 16.61 kJ mol-1 for the thickness of 0.005 m, and 16.97 kJ mol-1 for the thickness of 0.010 m. AIC and BIC can be additionally included to select models of drying.

Drying Kinetics of Continuous and Intermittent Heat Pump Drying of Green Soybean Seeds

2017 ◽  
Vol 13 (11) ◽  
Author(s):  
Haibo Zhao ◽  
Zhao Yang ◽  
Zhichao Tao
Keyword(s):  
Experimental Data ◽  
Heat Pump ◽  
Drying Kinetics ◽  
Percentage Error ◽  
Drying Rate ◽  
Soybean Seeds ◽  
Mean Square ◽  
Chi Square ◽  
Heat Pump Drying ◽  
Kinetics Of

AbstractThis paper is concerned with drying kinetics and models of heat pump drying (HPD) of green soybean. Experiments were done for continuous and intermittent drying with intermittency of 1, 3 and 6. Drying rate decreases sharply in continuous HPD process, while circuitously in intermittent HPD process. Peak drying rate values appear in every drying period of intermittent drying and differ a lot because of different intermittent ratios. In addition, various mathematical models were investigated to describe the HPD kinetics of green soybean seeds. Fitting suitability of the experimental data by models was specified as comparing the coefficient of correlation (R2), mean absolute percentage error (EMD%), Chi-squareΧ2and root mean square error (ERMS). The page model and 23rd model were found to be the most suitable models in describing the continuous and intermittent drying of green soybeans, respectively.

scholarly journals Drying kinetics of ‘gueroba’ (Syagrus oleracea) fruit pulp

2021 ◽  
Vol 25 (1) ◽  
pp. 23-29
Author(s):  
Ana P. P. Jorge ◽  
Weder N. Ferreira Junior ◽  
Lígia C. de M. Silva ◽  
Daniel E. C. de Oliveira ◽  
Osvaldo Resende
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Effective Diffusion ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Chi Square ◽  
Adequate Model ◽  
Nonlinear Regression Models ◽  
Water Diffusivity ◽  
Chi Square Test

ABSTRACT The ‘Gueroba’ fruit can be used to produce flours with potential for the development of new products from the ‘Cerrado’ socio-biodiversity. The objective was to estimate the drying kinetics and determine the effective diffusion coefficient and activation energy for the pulp of ‘gueroba’ fruits subjected to different drying temperatures. ‘Gueroba’ fruits were manually pulped, removing the mesocarp with the epicarp, and this material was identified as the pulp. The material was subjected to oven drying at temperatures of 40, 50, 60 and 70 °C. Nonlinear regression models were fitted to the experimental data. The most adequate model was selected through the coefficient of determination, mean relative and estimated errors, Chi-square test, AIC and BIC. As the drying temperature increases, the processing time to achieve the same moisture content decreases, due to the increase in water diffusivity inside the product. The Midilli model showed the best fit to the experimental data obtained. The effective diffusion coefficients of the pulp of ‘gueroba’ fruits showed magnitudes between 3.11 x 10-9 to 5.84 x 10-9 m2 s-1 for temperatures from 40 to 70 °C. The activation energy of the process was 18.34 kJ mol-1.

scholarly journals The effect of processing method on drying kinetics of Petrovská klobása, an artisan fermented sausage

2012 ◽  
Vol 18 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Predrag Ikonic ◽  
Ljiljana Petrovic ◽  
Tatjana Tasic ◽  
Marija Jokanovic ◽  
Snezana Savatic ◽  
...  
Keyword(s):  
Experimental Data ◽  
Processing Method ◽  
Coefficient Of Determination ◽  
Mean Square ◽  
Chi Square ◽  
Fermented Sausage ◽  
Drying Characteristics ◽  
Dry Fermented Sausage ◽  
Drying Behaviour ◽  
Kinetics Of

The drying behaviour of dry-fermented sausage Petrovsk? klob?sa ripened in traditional and industrial conditions has been studied. Obtained results indicated that sausages dried in industrial room (batch I) had higher weight loss and lower water activity (aw) values than counterparts from traditional/artisanal production (batch T). Difference in drying intensity between internal and external fractions of sausages was much more marked for batch I. The experimental data of water content in Petrovsk? klob?sa, dried in respective conditions, were compared with values predicted by seven different mathematical models. Comparing the coefficient of determination (r2), root mean square error (ERMS) and the reduced chi-square (?2) values of all equations, it was concluded that the Page mathematical model satisfactorily represents drying characteristics of Petrovsk? klob?sa both in traditional (0.990; 2.22 x 10-2 and 6.01 x 10-4, respectively) and industrial conditions (0.995; 1.79 x 10-2; 3.91 x 10-4, respectively).

scholarly journals Kinetics of drying of basil leaves (Ocimum basilicum L.) in the infrared

2012 ◽  
Vol 16 (12) ◽  
pp. 1346-1352 ◽  
Author(s):  
Renata C. dos Reis ◽  
Ivano A. Devilla ◽  
Diego P. R. Ascheri ◽  
Ana C. O. Servulo ◽  
Athina B. M. Souza
Keyword(s):  
Experimental Data ◽  
Ocimum Basilicum ◽  
Coefficient Of Determination ◽  
Chisquare Test ◽  
The Mean ◽  
Drying Curves ◽  
The One ◽  
Increasing Temperature ◽  
Air Circulation ◽  
Kinetics Of

The objective of this paper was to model the drying curves of the leaves of basil (Ocimum basilicum L.) in the infrared at temperatures of 50, 60, 70 and 80 ºC and to evaluate the influence of drying temperature on the color of dried leaves. Drying was conducted in infrared dryer with temperature and greenhouse air circulation. Experimental data were fitted to eight mathematical models. The magnitude of the coefficient of determination (R²), the mean relative error (P), the estimated mean error (SE) and chisquare test (χ2) were used to verify the degree of fitness of the models. From the study it was concluded that: a) the behavior of the drying curves of basil leaves was similar to most agricultural products, the drying times in the infrared were less than the drying times in an oven with air circulation, b) the mathematical drying model proposed by Midilli et al. (2002) was the one which best adjusted to the experimental data, c) the diffusion coefficient ranged from 9.10 x 10-12 to 2.92 x 10-11 m² s-1 and d) the color of the samples was highly influenced by drying, becoming darker due to loss of chlorophyll with increasing temperature.

scholarly journals Methods and techniques of research motivation and satisfaction of employees

2021 ◽  
Vol 9 (2) ◽  
pp. 53-63
Author(s):  
Dragana Pešić-Jenačković
Keyword(s):  
Analysis Of Variance ◽  
Employee Motivation ◽  
Test Point ◽  
Coefficient Of Determination ◽  
Business Success ◽  
Chi Square ◽  
Methods And Techniques ◽  
Chi Square Test ◽  
Using Data ◽  
The Impact

Motivation and employee satisfaction are very important precondition for the effectiveness of work and the achievement of set goals for individuals and organizations. Consequently, continuous measurement of employee motivation and satisfaction is essential to improve company's efficiency and improve human resource use. The results of a well-planned, detailed and adequate methods and techniques of research on employee motivation and satisfaction can be applied to the design of various schemes in order to reduce absenteeism and employee turnover and overall business success. In this paper, the emphasis is on the methodology of researching employee motivation and satisfaction. In addition to the elaboration of questionnaires with scales for measuring the motivation and satisfaction of employees, it is explained in which situations, in which types of questions and answers, respectively, types of data, and how certain statistical techniques are applied, such as: T-test, One-factor analysis of variance (ANOVA), Chi-square test, Point-two-series correlations. Also, the importance of using the subsequent post hoc test (LSD comparison) in the analysis of variance, as well as the indicators of correlation, the strength of the impact, such as: phi correlation coefficient, Kramer's coefficient and contingency coefficient, is pointed out in the Chi-square test. In addition to the mentioned techniques and indicators from SPSS, the role of certain indicators (eta squared and coefficient of determination) is calculated, which are calculated using data from research results and with the help of certain formulas

The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1859-1866 ◽  
Author(s):  
Hui-Ling Wang ◽  
Zhao-Hui Yang ◽  
Jing Huang ◽  
Li-Ke Wang ◽  
Cheng-Liu Gou ◽  
...  
Keyword(s):  
Sample Thickness ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Dewatered Sludge ◽  
Drying Curves ◽  
Sludge Drying ◽  
The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

scholarly journals Enhanced sorption capacity of the metal-dye system from water effluents by using polish activated industrial waste

2020 ◽  
Author(s):  
Eleonora Sočo ◽  
Jan Kalembkiewicz
Keyword(s):  
Coal Fly Ash ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Coefficient Of Determination ◽  
Isotherm Models ◽  
Particle Model ◽  
Particle Diffusion ◽  
Hexadecyltrimethylammonium Bromide ◽  
Chi Square ◽  
Chi Square Test

Abstract The activated coal fly ash (FA) treated with NaOH and hexadecyltrimethylammonium bromide (HDTMABr) was used as adsorbent for removal of cadmium(II) ions and rhodamine B (RB) form an aqueous solution. Characterization of FA and FA-HDTMABr were done by using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The sorption equilibrium in the system were analysed by isotherm models, such as Freundlich, Langmuir, generalized Langmiur-Freundlich, Redlich-Peterson, Jovanović, extended Jovanović, Tóth, Fumkin-Fowler-Guggenheim, Fowler-Guggenheim-Jovanović-Freundlich, Temkin, Dubinin-Radushkevich, Halsey, Brunauer Emmett and Teller. The evaluation of fitting of the isotherms studied experimentally points was carried out by means of the reduced chi-square test and the coefficient of determination. The maximum monolayer adsorption capacity of the FA-HDTMABr was found to be 744 mg·g−1 and 666 mg·g−1 for Cd(II) and RB, respectively. The PFO, PSO, Elovich mass transfer, liquid film diffusion and intra-particle diffusion models were analysed. Sorption kinetics data were well fitted by PSO model. The Elovich and intra-particle model also revealed that there are two separate stages in the sorption process, namely, the external diffusion and the inter-particle diffusion.

scholarly journals Thin Layer Drying Kinetics Modelling of Curry Leaves (Murraya koenigii L.) in Cabinet Dryer

2018 ◽  
Vol 2 ◽  
pp. 53-58
Author(s):  
Arjun Ghimire ◽  
Nirajan Magar
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Effective Diffusivity ◽  
Coefficient Of Determination ◽  
Murraya Koenigii ◽  
Small Tree ◽  
Chi Square ◽  
Kinetics Modelling ◽  
Curry Leaves ◽  
Thin Layer Drying

Curry leaves (Murraya koenigii L.) are the sweet smelling leaves of small tree of Rutaceae family native to Southwest Asia. In this study, the effect of temperatures (50, 55 and 60°C) on the drying of curry leaves was investigated. The experimental data were fitted to six thin layer mathematical models (Newton, Page, Handerson and Pabis, logarithmic, two-term exponential and Midilli et al). The models were evaluated in terms of coefficient of determination (R2), chi square (χ2) and root mean square error (RMSE). The Midilli et al model was best fitted to the experimental data of all the models evaluated. The effective diffusivity was calculated using Fick's diffusion equation, and the value varied from 2.07×10-12 m2/s to 2.643×10-12 m2/s. The activation energy and the diffusivity constant were found to be 21.808 kJ/mol and 4.667×10-8 m2/s respectively.

scholarly journals Effects of Infrared-Assisted Refractance Window™ Drying on the Drying Kinetics, Microstructure, and Color of Physalis Fruit Purée

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 343
Author(s):  
Luis Puente-Díaz ◽  
Oliver Spolmann ◽  
Diego Nocetti ◽  
Liliana Zura-Bravo ◽  
Roberto Lemus-Mondaca
Keyword(s):  
Statistical Tests ◽  
Coefficient Of Determination ◽  
Drying Process ◽  
Chi Square ◽  
Ir Radiation ◽  
Drying Time ◽  
Drying Curves ◽  
Effective Diffusivities ◽  
Drying Conditions ◽  
Fruit Purée

The objective of this work was to study the influence of the drying temperature, infrared (IR) radiation assistance, and the Mylar™ film thickness during Physalis fruit purée drying by the Refractance Window™ (RW™) method. For this, a RW™ dryer layout with a regulated bath at working temperatures of 60, 75, and 90 °C, Mylar™ thicknesses of 0.19, 0.25, 0.30 mm and IR radiation of 250 W for assisting RW™ drying process was used. Experimental curves data were expressed in moisture ratio (MR) in order to obtain moisture effective diffusivities (non-assisted RW™: Deff = 2.7–10.1 × 10−10 m2/s and IR-assisted RW™: Deff = 4.2–13.4 × 10−10 m2/s) and further drying curves modeling (Page, Henderson–Pabis, Modified Henderson–Pabis, Two-Term, and Midilli–Kucuk models). The Midilli–Kucuk model obtained the best-fit quality on experimental curves regarding statistical tests applied (Coefficient of Determination (R2), Chi-Square (χ2) and Root Mean Square Error (RMSE). Microscopical observations were carried out to study the RW™ drying conditions effect on microstructural changes of Physalis fruit purée. The main findings of this work indicated that the use of IR-assisted RW™ drying effectively accelerates the drying process, which achieved a decrease drying time around 60%. Thus, this combined RW™ process is strongly influenced by the working temperature and IR-power applied, and slightly by Mylar™ thickness.

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