Baking Pizza by Infrared Radiation and Conduction Heat Transfers and Mass Transfer in Unsteady State

2021 ◽  
pp. 157-164
Author(s):  
M. Kemal Atesmen
Keyword(s):  
Mass Transfer ◽  
Infrared Radiation ◽  
Unsteady State ◽  
Heat Transfers

Unsteady-state shear strategies to enhance mass-transfer for the implementation of ultrapermeable membranes in reverse osmosis: A review

Desalination ◽  
2015 ◽  
Vol 356 ◽  
pp. 328-348 ◽  
Author(s):  
Farhad Zamani ◽  
Jia Wei Chew ◽  
Ebrahim Akhondi ◽  
William B. Krantz ◽  
Anthony G. Fane
Keyword(s):  
Mass Transfer ◽  
Reverse Osmosis ◽  
Unsteady State ◽  
Enhance Mass

Mass Transfer Technique for Investigation of Heat Transfer by Jet-Impingement Systems

1972 ◽  
Vol 14 (6) ◽  
pp. 389-392 ◽  
Author(s):  
J. Ward ◽  
F. J. K. Ideriah ◽  
S. D. Probert ◽  
A. Duggan
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Jet Impingement ◽  
Impinging Jets ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Heat Transfers

The technique of using mass transfer measurements (by sublimation of naphthalene) together with the Chilton–Colburn analogy is shown to be feasible for evaluation of heat transfers from impinging jets. The method is then used to determine heat transfer coefficients at the burner walls in models of jet–impingement furnaces.

A Linear Driving Force (LDF) Approximation of Moisture Diffusion Kinetics in White Rice

2008 ◽  
Vol 4 (8) ◽  
Author(s):  
Abhishek Dutta ◽  
Anirban Chanda ◽  
Runu Chakraborty
Keyword(s):  
Mass Transfer ◽  
Finite Difference ◽  
Driving Force ◽  
Rice Grain ◽  
Unsteady State ◽  
Moisture Uptake ◽  
Linear Diffusion ◽  
White Rice ◽  
Linear Driving Force ◽  
Kinetics Of

Soaking characteristics of white rice grain in water are studied at 25, 40, 60, 70 and 80 °C. The kinetics of mass transfer are modeled using a linear driving force (LDF) approximation with constant diffusivity, which is capable of predicting the moisture ratio profile with time. This approximation is a relatively new approach in food engineering applications for systems in which the rate of mass transfer is controlled by intra-particle diffusion and nonlinear adsorption through porous adsorbent. The mass transfer is also modeled through Fick's law for unsteady-state diffusion using finite difference (FD) method, and compared with the LDF model. In general, the moisture uptake curves calculated with this new approximation compare favorably with the finite difference solution obtained in spherical coordinates, producing results of similar accuracy. Both the methods give a good agreement with the experimental data. The values of the effective diffusion coefficients are between 7.33×10-11 m2/s and 1.43×10-10 m2/s for a temperature of 25 and 80 °C respectively. Although gelatinization of starch is observed at a higher temperature which influences the increase in moisture content, the moisture uptake curves calculated with this new approximation compare favorably with the numerical solution of the non-linear diffusion equation. As such, it can be safely used to predict the unsteady-state moisture absorption kinetics of a rice grain, for the temperature range investigated.

Transient Wax Gel Formation Model for Shut-In Subsea Pipelines

2009 ◽  
Author(s):  
Chiedozie Ekweribe ◽  
Faruk Civan
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Carbon Number ◽  
Transient State ◽  
Transient Heat Transfer ◽  
Gel Formation ◽  
Unsteady State ◽  
Formation Model ◽  
Subsea Pipeline ◽  
Subsea Pipelines

Physics of wax gel formation during shut-in is analyzed and described over a cross-section of a typical subsea pipeline. Two regions are identified during this process: the liquid and gel regions. Phase transition is assumed to occur at the liquid-gel interface. Unsteady-state heat and mass transfer models are proposed for each region. Two diffusion streams are evaluated: the dissolved wax molecules moving from the pipe center towards the wall due to temperature gradient and subsequently concentration gradient and the wax molecules diffusing from the liquid-gel interface into the gel deposit. This model is essentially the modification of the model given by Bhat et al [1] which considered transient heat transfer and neglected mass transfer of wax molecules through the gel deposit and the model by Singh et al [2] which considered transient mass transfer of molecules with carbon numbers higher than the critical carbon number (CCN) necessary for wax diffusion into gel deposit but did not consider transient heat transfer effects during the cooling process. This paper presents a transient-state formulation circumventing the limitations of these previous models and better represents the true cooling and gelation process occurring in a shut-in subsea pipeline filled with waxy crude.

scholarly journals Binary S and MS Stars

1992 ◽  
Vol 151 ◽  
pp. 157-166
Author(s):  
Hollis R. Johnson
Keyword(s):  
Mass Transfer ◽  
White Dwarf ◽  
Infrared Radiation ◽  
Large Fraction ◽  
Circumstellar Dust ◽  
Agb Stars ◽  
Hot Gas ◽  
Popular View ◽  
Process Elements ◽  
Gas Cloud

We assemble and discuss evidence for binarity in S and MS stars - stars that are enriched in s-process elements. A popular view is that Tc-deficient S and MS stars are not thermally pulsing AGB stars but are mass-transfer binaries. We describe several methods used to test this hypothesis through a search for the putative white-dwarf companion: (1) periodic radial velocity variations, (2) direct observation of the hot companions with IUE, (3) evidence of a hot gas cloud (hotter than a chromosphere) in the system, and (4) evidence of circumstellar dust as revealed through infrared radiation. Results of these methods are compared. All evidence supports the idea that Tc-deficient S and MS stars are mass-transfer binaries, and a large fraction appear to be interactive.

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