Drying of Apple Slices in Combined Heat and Power (CHP) Dryer: Comparison of Mathematical Models and Neural Networks

2013 ◽  
Vol 8 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Seyed Hashem Samadi ◽  
Barat Ghobadian ◽  
GholamHassan Najafi ◽  
Ali Motevali ◽  
Saeid Faal
Keyword(s):  
Mathematical Models ◽  
Industrial Process ◽  
Combined Heat And Power ◽  
Suitable Model ◽  
Apple Slices ◽  
Different Temperatures ◽  
Drying Behavior ◽  
Artificial Neural Network Ann ◽  
Product Thickness ◽  
Apple Slice

Abstract Consuming a high amount of energy in industrial dryer makes the drying as an important and highly energy-intensive industrial process. In this study, the required energy for drying of apple slice was supplied from the outlet heat of an engine generation set exhaust. The drying behavior of apple slice was studied in a combined heat and power (CHP) dryer system at four engine load levels (25, 50, 75, and 100%) in order to provide different temperatures (50, 65, 80, and 95°C), and at three levels of drying product thickness (3, 5, and 7 mm) with the constant air flow velocity of 1 m/s. The empirical data from experiments with variants of semi-theoretical and empirical models were evaluated and finally, a suitable model proposed by Midilli et al. was selected to be the best model, as for as the RMSE, R2, and χ2 criterion is concerned. Comparing the results from implementing artificial neural network (ANN) and mathematical models, it was found that the dynamic ANNs is more powerful for modeling the drying process of apple slice in a CHP dryer system than static ANNs and mathematical models.

Influence of Drying Conditions and Mathematical Models on the Thin-Layer Drying of Mushrooms

2014 ◽  
Author(s):  
A. Stegou-Sagia ◽  
D. V. Fragkou
Keyword(s):  
Mass Transfer ◽  
Thin Layer ◽  
Mathematical Models ◽  
Drying Methods ◽  
Suitable Model ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Models ◽  
Drying Rates

In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers such as hot air cabinet dryer and fluidized bed dryer with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model.

Effect of Microstructural Characteristics of Electroless Nickel Metallisation on Solderability to Pb-Free Solder Alloys

2005 ◽  
Author(s):  
Changqing Liu ◽  
David A. Hutt ◽  
Dezhi Li ◽  
Paul P. Conway
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Bulk Composition ◽  
Industrial Process ◽  
Surface Characteristics ◽  
Electroless Nickel ◽  
X Ray ◽  
N2 Atmosphere ◽  
Different Temperatures ◽  
Free Solder

This paper aims to gain an insight into the correlation between the microstructure and surface composition of electroless Ni-P and its behaviour during soldering with Pb free alloys including Sn-3.8Ag-0.7Cu, Sn-3.5Ag and Sn-0.7Cu. Ni-P coatings with different P contents were produced through an industrial process on copper metal substrates. The surface morphology of these coatings was observed by Scanning Electron Microscopy (SEM) and the bulk composition was analyzed by means of Energy Dispersive X-ray analysis (EDX). The mechanical properties of the coatings were evaluated by nano-indentation testing under different maximum loads. However, to understand the behaviour of P in Ni-P coatings and deterioration of the coating surfaces during exposure to air, the surfaces of the coatings were also characterised by X-ray Photoelectron Spectroscopy (XPS) for storage at different temperatures. The dependence of the solderability of Ni-P coatings on the storage time and temperature was investigated by wetting balance testing, using an inactive or active flux with or without an inert N2 atmosphere. Finally, the solderability of Ni-P coatings to Pb free solders is correlated with their composition and microstructure (e.g. surface characteristics).

scholarly journals Developing mathematical models for global solar radiation intensity estimation at Shakardara, Kabul

2021 ◽  
Vol 4 (2) ◽  
pp. 133-138
Author(s):  
Abdul Basit Da’ie
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Mathematical Models ◽  
Radiation Intensity ◽  
Global Solar Radiation ◽  
Suitable Model ◽  
Intensity Estimation ◽  
Solar Radiation Intensity ◽  
Sunshine Hours ◽  
Atmospheric Data

Solar energy properties such as Global Solar Radiation (GSR) intensity could be determined in either methods, experimentally or theoretically. Unfortunately, in most countries including Afghanistan, the first method which is more acceptable, but due to the high cost, maintenance and calibration requirements is not available. Therefore, an alternative widely used way is the second one which is model developments based on the meteorological (atmospheric) data; specially the sunny hours. The aim of this study at Shakardara area is to estimate atmospheric transparency percentage on 2017, determining the angstrom model coefficients and to introduce a suitable model for global solar radiation prediction. The hourly observed solar radiation intensity H (WHm-2 ) and sunshine hours S (

scholarly journals Fitting mathematical models to lactation curves from holstein cows in the southwestern region of the state of Parana, Brazil

2015 ◽  
Vol 87 (1) ◽  
pp. 503-517 ◽  
Author(s):  
Abílio G.T. Ferreira ◽  
Douglas S. Henrique ◽  
Ricardo A.M. Vieira ◽  
Emilyn M. Maeda ◽  
Altair A. Valotto
Keyword(s):  
Mathematical Models ◽  
Milk Production ◽  
Information Criterion ◽  
The State ◽  
Holstein Cows ◽  
Suitable Model ◽  
Almost All ◽  
Quality Of Fit ◽  
Wood Model

The objective of this study was to evaluate four mathematical models with regards to their fit to lactation curves of Holstein cows from herds raised in the southwestern region of the state of Parana, Brazil. Initially, 42,281 milk production records from 2005 to 2011 were obtained from "Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH)". Data lacking dates of drying and total milk production at 305 days of lactation were excluded, resulting in a remaining 15,142 records corresponding to 2,441 Holstein cows. Data were sorted according to the parity order (ranging from one to six), and within each parity order the animals were divided into quartiles (Q25%, Q50%, Q75% and Q100%) corresponding to 305-day lactation yield. Within each parity order, for each quartile, four mathematical models were adjusted, two of which were predominantly empirical (Brody and Wood) whereas the other two presented more mechanistic characteristics (models Dijkstra and Pollott). The quality of fit was evaluated by the corrected Akaike information criterion. The Wood model showed the best fit in almost all evaluated situations and, therefore, may be considered as the most suitable model to describe, at least empirically, the lactation curves of Holstein cows raised in Southwestern Parana.

Numerical analysis of hemivariational inequalities in contact mechanics

Acta Numerica ◽  
2019 ◽  
Vol 28 ◽  
pp. 175-286 ◽  
Author(s):  
Weimin Han ◽  
Mircea Sofonea
Keyword(s):  
Numerical Analysis ◽  
Mathematical Models ◽  
Contact Mechanics ◽  
Numerical Solutions ◽  
Deformable Body ◽  
Industrial Process ◽  
Contact Problems ◽  
Hemivariational Inequalities ◽  
Uniqueness Results ◽  
Simulation Results

Contact phenomena arise in a variety of industrial process and engineering applications. For this reason, contact mechanics has attracted substantial attention from research communities. Mathematical problems from contact mechanics have been studied extensively for over half a century. Effort was initially focused on variational inequality formulations, and in the past ten years considerable effort has been devoted to contact problems in the form of hemivariational inequalities. This article surveys recent development in studies of hemivariational inequalities arising in contact mechanics. We focus on contact problems with elastic and viscoelastic materials, in the framework of linearized strain theory, with a particular emphasis on their numerical analysis. We begin by introducing three representative mathematical models which describe the contact between a deformable body in contact with a foundation, in static, history-dependent and dynamic cases. In weak formulations, the models we consider lead to various forms of hemivariational inequalities in which the unknown is either the displacement or the velocity field. Based on these examples, we introduce and study three abstract hemivariational inequalities for which we present existence and uniqueness results, together with convergence analysis and error estimates for numerical solutions. The results on the abstract hemivariational inequalities are general and can be applied to the study of a variety of problems in contact mechanics; in particular, they are applied to the three representative mathematical models. We present numerical simulation results giving numerical evidence on the theoretically predicted optimal convergence order; we also provide mechanical interpretations of simulation results.

Single Layer Drying Behavior of Apple Slices in a Microwave Dryer

2011 ◽  
Vol 312-315 ◽  
pp. 842-847 ◽  
Author(s):  
Soner Çelen ◽  
Kamil Kahveci ◽  
Ugur Akyol
Keyword(s):  
Microwave Power ◽  
Colour Change ◽  
Single Layer ◽  
Drying Time ◽  
Apple Slices ◽  
Drying Behavior ◽  
Drying Behaviour ◽  
Drying Conditions ◽  
Mean Square Errors ◽  
Microwave Dryer

In this study, the drying behaviour of single layer apple slices of 5mm thickness in a microwave dryer was investigated experimentally for four different microwave power levels (90 W, 180 W, 360 W and 600 W) and suitability of drying models available in the literature in simulating the drying behaviour of apple slices was determined by statistical analysis. The performance of these models was determined by comparing the coefficients of determination (R), reduced chi-squares (χ2) and root mean square errors (RMSE) of the models. The results show that drying time and energy consumption decreases considerably with increasing microwave power. The results also show that, among of the models proposed, the Verma et al. model gives the best fit with experimental data for all drying conditions considered. In order to determine the colour change of apple, a colour meter was also used in this study and found that L* and a* values were not significantly different from the values of the fresh apples.

EBSD Study of Substructure and Texture Formation in Dual-Phase Steel Sheets for Semi-Finished Products

2010 ◽  
Vol 160 ◽  
pp. 251-256 ◽  
Author(s):  
M. Masimov ◽  
N. Peranio ◽  
B. Springub ◽  
Franz Roters ◽  
Dierk Raabe
Keyword(s):  
Cold Rolling ◽  
Annealing Temperature ◽  
Texture Evolution ◽  
Industrial Process ◽  
Dual Phase ◽  
Technological Parameters ◽  
Dual Phase Steels ◽  
Final Annealing ◽  
Steel Sheets ◽  
Different Temperatures

Using SEM/EBSD the substructure and texture evolution in dual phase steels in the first steps of the process chain, i.e. hot rolling, cold rolling, and following annealing were characterized. In order to obtain dual phase steels with high ductility and high tensile strength an industrial process was reproduced by cold rolling of industrially hot rolled steel sheets of a thickness of 3.75 mm with ferrite and pearlite morphology down to a thickness of 1.75 mm and finally annealing at different temperatures. Such technique allows a compilation of ferrite and martensite morphology typical for dual phase steels. Due to the competition between recovery, recrystallization and phase trans-formation during annealing a variety of ferrite martensite morphologies was produced by promoting one of the mechanisms through the variation of technological parameters such as heating rate, intercritical annealing temperature, annealing time, cooling rate and the final annealing temperature. Annealing induced changes of the mechanical properties were determined by hardness measurements and are discussed on the basis of the results of the substructure investigations.

Osmotic Dehydration of Apple Slices Using a Sucrose/CaCl2 Combination To Control Spoilage Caused by Botrytis cinerea, Colletotrichum acutatum, and Penicillium expansum

2001 ◽  
Vol 64 (9) ◽  
pp. 1425-1429 ◽  
Author(s):  
CATHERINE O. CHARDONNET ◽  
CARL E. SAMS ◽  
WILLIAM S. CONWAY ◽  
JOHN R. MOUNT ◽  
FRANCES A. DRAUGHON
Keyword(s):  
Botrytis Cinerea ◽  
Calcium Uptake ◽  
Osmotic Dehydration ◽  
Penicillium Expansum ◽  
Colletotrichum Acutatum ◽  
Mass Ratio ◽  
Effective Combination ◽  
Sucrose Solutions ◽  
Apple Slices ◽  
Apple Slice

The efficacy of sucrose combined with CaCl2 during osmotic dehydration (OD) was tested for the control of Botrytis cinerea, Colletotrichum acutatum, and Penicillium expansum growth on lightly processed apple slices. The objective of this work was to determine whether the addition of CaCl2 in the osmotic solutions would limit the proliferation of fungal decay organisms. Slices were submitted to OD for 1 h at 25°C in solutions containing 5 to 65% sucrose. Calcium chloride was added to a similar set of sucrose solutions at 0 to 8%. Control slices were made of untreated slices, and slices were processed in water. The mass ratio of the slices did not vary when fruit pieces were processed in solutions containing 5 to 65% sucrose. These slices showed a high susceptibility to spoilage compared to the control slices not submitted to OD: a significant twofold and 60% increase in decay area caused by B. cinerea and P. expansum, respectively, was observed when slices were processed in 50% sucrose/0% CaCl2; C. acutatum showed a significant 50% increase in decay area when slices were processed in 20% sucrose/0% CaCl2. Calcium uptake was significantly increased when slices were processed in CaCl2 solutions, and the highest Ca content was observed when processed in 8% CaCl2, reaching 40 times that of the control slices processed in water. Calcium-treated slices were less susceptible to spoilage by all three pathogens, and the most effective combination in reducing apple slice spoilage was 20 to 30% sucrose combined with 2% CaCl2.

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