Comparative semi‐empirical modeling and physico‐functional analysis of hot‐air and vacuum dried puran powder

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Nilesh Balasaheb Kardile ◽  
Prabhat Kumar Nema ◽  
Barjinder Pal Kaur ◽  
Shubhangi Mahadeo Thakre
Keyword(s):  
Functional Analysis ◽  
Empirical Modeling ◽  
Hot Air ◽  
Semi Empirical

Study on Two-Phase Fuel Distributions in High-Speed Hot Transverse Air Stream

1986 ◽  
Vol 108 (3) ◽  
pp. 485-490
Author(s):  
Mao-lin Yang ◽  
Shan-jian Gu ◽  
Xiang-yi Li
Keyword(s):  
High Speed ◽  
Empirical Method ◽  
Mass Center ◽  
Two Phase ◽  
Fuel Distribution ◽  
Hot Air ◽  
Air Stream ◽  
Cold Stream ◽  
Fuel Evaporation ◽  
Semi Empirical

It was found that fuel distribution in a hot high-speed transverse air stream differed greatly from that in a cold stream. In a hot air stream there exist two-phase fuel distributions, and hence, two mass center lines extending downstream. Experimental results of fuel distributions are presented. By using the model of trajectory with diffusion and also considering the fuel evaporation, a semi-empirical method to predict two-phase fuel distributions has been developed.

scholarly journals Polyatomic Ion-Induced Electron Emission (IIEE) in Electrospray Thrusters

Aerospace ◽  
2020 ◽  
Vol 7 (11) ◽  
pp. 153
Author(s):  
Jared M. Magnusson ◽  
Adam L. Collins ◽  
Richard E. Wirz
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Complex Analysis ◽  
Secondary Electron Emission ◽  
State Theory ◽  
Empirical Modeling ◽  
Threshold Velocity ◽  
Molecular Ion ◽  
And Performance ◽  
Semi Empirical

To better characterize the lifetime and performance of electrospray thrusters, electron emission due to electrode impingement by the propellant cation 1-ethyl-3-methylimidazolium (EMI+) has been evaluated with semi-empirical modeling techniques. Results demonstrate that electron emission due to grid impingement by EMI+ cations becomes significant once EMI+ attains a threshold velocity of ∼9×105 cm s−1. The mean secondary electron yield, γ¯, exhibits strong linearity with respect to EMI+ velocity for typical electrospray operating regimes, and we present a simple linear fit equation corresponding to thruster potentials greater than 1 kV. The model chosen for our analysis was shown to be the most appropriate for molecular ion bombardments and is a useful tool in estimating IIEE yields in electrospray devices for molecular ion masses less than ∼1000 u and velocities greater than ∼106 cm s−1. Droplet-induced electron emission (DIEE) in electrospray thrusters was considered by treating a droplet as a macro-ion, with low charge-to-mass ratio, impacting a solid surface. This approach appears to oversimplify back-spray phenomena, meaning a more complex analysis is required. While semi-empirical models of IIEE, and the decades of solid state theory they are based upon, represent an invaluable advance in understanding secondary electron emission in electrospray devices, further progress would be gained by investigating the complex surfaces the electrodes acquire over their lifetimes and considering other possible emission processes.

SEMI-EMPIRICAL MODELING OF THE PHOTOSPHERE, CHROMOPSHERE, TRANSITION REGION, AND CORONA OF THE M-DWARF HOST STAR GJ 832

2016 ◽  
Vol 830 (2) ◽  
pp. 154 ◽  
Author(s):  
J. M. Fontenla ◽  
Jeffrey L. Linsky ◽  
Jesse Witbrod ◽  
Kevin France ◽  
A. Buccino ◽  
...  
Keyword(s):  
Transition Region ◽  
Empirical Modeling ◽  
Semi Empirical ◽  
M Dwarf

Semi-empirical modeling of the optical gap of amorphous hydrogenated nitrogenated carbon films

2000 ◽  
Vol 18 (5) ◽  
pp. 2466 ◽  
Author(s):  
Larissa L. E. Santo ◽  
Steven F. Durrant ◽  
Elidiane C. Rangel ◽  
Douglas S. Galvão ◽  
Mário A. Bica de Moraes
Keyword(s):  
Carbon Films ◽  
Empirical Modeling ◽  
Optical Gap ◽  
Semi Empirical ◽  
Nitrogenated Carbon

Theoretical and Empiriical Modeling of the Rheology of Fresh Cement Pastes

1992 ◽  
Vol 289 ◽  
Author(s):  
Gebran N. Karam
Keyword(s):  
Experimental Investigation ◽  
Rheological Properties ◽  
Empirical Model ◽  
General Framework ◽  
Theoretical Modeling ◽  
Empirical Modeling ◽  
Rheological Characteristics ◽  
Concentrated Suspensions ◽  
Cement Pastes ◽  
Semi Empirical

AbstractThe most important property of cements and concretes after strength is the workability, which is controlled by the rheological characteristics of the mix. Theoretical modeling having proved complicated and in some cases mathematically untractable, cement specialists have concentrated on empirical based models for the last two decades. The major theoretical contributions to date on the properties of colloidal and concentrated suspensions are summarized and a general framework for theoretical modeling of cement viscosity is established. The empirical modeling and the experimental investigation of the rheological properties of fresh cements are reviewed and discussed. A semi-empirical model is proposed and its validity tested in the interpretation of some published experimental results.

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