A Comparative Analysis of the Kinetic Experiments in Polyethylene Pyrolysis

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Pravin Kannan ◽  
Salisu Ibrahim ◽  
K. Suresh Kumar Reddy ◽  
Ahmed Al Shoaibi ◽  
C. Srinivasakannan
Keyword(s):  
Kinetic Parameters ◽  
Heating Rate ◽  
Kinetic Data ◽  
Mass Transfer Resistance ◽  
Review Of Literature ◽  
Transfer Resistance ◽  
Lower Heating Rate ◽  
Polymer Pyrolysis ◽  
The Difference ◽  
Lower Heating

A review of literature has been conducted to survey the kinetic data of low-density polyethylene (LDPE) pyrolysis. The review reveals large variations in the reported global kinetic parameters. The cause of variation has been identified to be the difference in the experimental techniques, including thermogravimetric analysis (TGA) and non-TGA methods. Even within the nonisothermal TGA data, large variations have been observed at heating rate of 20 K/min, while the variations are insignificant at lower heating rate regimes (2–10 K/min), indicating the influence of heat/mass transfer resistance controlling the kinetics. Detailed analysis revealed that most of the current techniques are unable to capture all the relevant data necessary for estimating the kinetic parameters of the aforementioned process. The outcome of this review work thrusts the need for a better experimental technique to estimate the kinetic parameters of complex reactions, such as polymer pyrolysis.

Effect of Heating Rate on Sintered Microstructure of W-Cu Nanocomposite Powder Produced Using W-CuO Mixture

2004 ◽  
Vol 449-452 ◽  
pp. 1125-1128
Author(s):  
Dae Gun Kim ◽  
Gil Su Kim ◽  
Jin Chun Kim ◽  
Sung Tag Oh ◽  
Young Do Kim
Keyword(s):  
Heating Rate ◽  
Nanocomposite Powder ◽  
Lower Heating Rate ◽  
Nanocomposite Powders ◽  
Heating Up ◽  
Lower Heating

The sintered microstructure homogeneity of W-15wt%Cu nanocomposite powders prepared from W-CuO mixture was investigated. The increment of heating rate considerably affected the homogeneity of sintered microstructure. In case of the higher heating rate, the microstructure was more homogeneous than that of the lower heating rate by reason of Cu- exudation during heating-up process.

"Scan" behaviour in Podarcis muralis: the use of vantage points by an actively foraging lizard

1993 ◽  
Vol 14 (3) ◽  
pp. 247-259 ◽  
Author(s):  
Roger Avery ◽  
Annabel Basker ◽  
Claudia Corti
Keyword(s):  
Heating Rate ◽  
Rapid Heating ◽  
Thin Strip ◽  
Podarcis Muralis ◽  
Podarcis Sicula ◽  
Lacerta Viridis ◽  
Lower Heating Rate ◽  
Vantage Points ◽  
Rapid Heating Rate ◽  
Lower Heating

AbstractTwo adult Podarcis muralis whose normal movements incorporated the flat top of a wall, frequently paused so that they were looking outwards from an edge ("scan" posture), especially during longer (≥9 s) periods immobile. Investigations of the posture on raised wooden platforms in outdoor enclosures, using two juvenile lizards, showed that (1) lizards spent significantly more time on platforms than would be expected from random movement, and this was not because wood is a favoured substrate for basking; (2) lizards which were immobile on platforms spent significantly more time at edges than would be expected by chance; (3) body orientations at 67.5-112.5° to the edge were the most frequent and these were maintained for significantly longer periods than the remaining orientations; exceptions were from 0800-0900 h when orientation was often parallel to the edge facing the sun and from 1200-1300 h with only a thin strip of shade at 45°, into which the lizards fitted themselves. Lizards basking in the laboratory beneath a tungsten bulb at the edge of a raised platform adopted outward-facing orientations when the platform height was ≥6 mm. When presented with a choice between basking more effectively (i.e. rapid heating rate) or adopting the "scan" posture at an edge with a lower heating rate or with no heating, they opted for the former. Podarcis sicula, P. filfolensis, Lacerta viridis and L. vivipara all showed an excess of outward-facing orientations when the basking bulbs were place near edges of platforms, but Psammodromus hispanicus did not. Only the two Podarcis species, however, spent more time on raised platforms than would be expected by chance when basking was possible at many sites in an arena.

Characterization of kinetic parameters and mass transfer resistance in an aerobic fixed-bed reactor by in-situ respirometry

2019 ◽  
Vol 146 ◽  
pp. 194-202
Author(s):  
Alberto Ordaz ◽  
Rocio Ramirez ◽  
Gabriel R. Hernandez-Martinez ◽  
Manuel Carrión ◽  
Frédéric Thalasso
Keyword(s):  
Mass Transfer ◽  
Kinetic Parameters ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Mass Transfer Resistance ◽  
Transfer Resistance

Coalescence of Cu contacted nanoparticles with different heating rates: A molecular dynamics study

2016 ◽  
Vol 30 (30) ◽  
pp. 1650212 ◽  
Author(s):  
Qibin Li ◽  
Tao Fu ◽  
Tiefeng Peng ◽  
Xianghe Peng ◽  
Chao Liu ◽  
...  
Keyword(s):  
Heating Rate ◽  
Gyration Radius ◽  
Cu Nanoparticles ◽  
Heating Rates ◽  
Shrinkage Ratio ◽  
Initial Stage ◽  
Fundamental Understanding ◽  
Lower Heating Rate ◽  
And Diffusion ◽  
Lower Heating

The coalescence, the initial stage of sintering, of two contacted Cu nanoparticles is investigated under different heating rates of 700, 350 and 233 K/ns. The nanoparticles coalesced rapidly at the initial stage when the temperature of the system is low. Then, the nanoparticles collided softly in an equilibrium period. After the system was increased to a high temperature, the shrinkage ratio, gyration radius and atoms’ diffusion started to change dramatically. The lower heating rate can result in smaller shrinkage ratio, larger gyration radius and diffusion of atoms. However, the growth of sintering neck is hardly influenced by the heating rate. The results provide a theoretical guidance for the fundamental understanding and potential application regarding nanoparticle sintering.

Analysis of Heat and Mass Transfer Between a Desiccant-Air System in a Packed Tower

1987 ◽  
Vol 109 (2) ◽  
pp. 89-93 ◽  
Author(s):  
P. Gandhidasan ◽  
M. Rifat Ullah ◽  
C. F. Kettleborough
Keyword(s):  
Mass Transfer ◽  
Gas Phase ◽  
Heat And Mass Transfer ◽  
Packing Material ◽  
Mass Transfer Resistance ◽  
Liquid Desiccant ◽  
Governing Equations ◽  
Packed Tower ◽  
Transfer Resistance ◽  
Steady State Model

Heat and mass transfer analysis between a desiccant-air contact system in a packed tower has been studied in application to air dehumidification employing liquid desiccant, namely calcium chloride. Ceramic 2 in. Raschig rings are used as the packing material. To predict the tower performance, a steady-state model which considers the heat and mass transfer resistances of the gas phase and the mass transfer resistance of the liquid phase is developed. The governing equations are solved on a digital computer to simulate the performance of the tower. The various parameters such as the effect of liquid concentration and temperature, air temperature and humidity and the rates of flow of air and liquid affecting the tower performance have been discussed.

scholarly journals Reply to Comments on ‘Effect of heating rate on kinetic parameters of β-irradiated Li2B4O7:Cu,Ag,P in TSL measurements’

2009 ◽  
Vol 20 (5) ◽  
pp. 058002
Author(s):  
A (Turkler) Ege ◽  
E (Ekdal) Tekin ◽  
T Karali ◽  
N Can ◽  
M Prokić
Keyword(s):  
Kinetic Parameters ◽  
Heating Rate

Thermogravimetric Analysis of Glucose-Based and Fructose-Based Carbohydrates

2013 ◽  
Vol 805-806 ◽  
pp. 265-268 ◽  
Author(s):  
Fang Ming Cui ◽  
Xiao Yuan Zhang ◽  
Li Min Shang
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Kinetic Parameters ◽  
Degree Of Polymerization ◽  
Experiment Data ◽  
Pyrolysis Characteristics ◽  
The Difference ◽  
Kinetic Calculations

Thermogravimetric analysis (TGA) was employed to study the pyrolysis characteristics of four glucose-based and three fructose-based carbohydrates. Kinetic parameters were calculated based on the experiment data. The results indicated that the starting and maximal pyrolysis temperatures of the glucose-based carbohydrates were increased steadily as the rising of their degree of polymerization (DP). The fructose-based carbohydrates exhibited similar pyrolysis behaviors as the glucose-based carbohydrates, but the difference was smaller. Kinetic calculations revealed that the activation energy values of the glucose-based carbohydrates were higher than those of the fructose-based carbohydrates, indicating the glucose-based carbohydrates were more difficult to decompose than the fructose-based carbohydrates.

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