scholarly journals Studies on the Transport of Aromatic Solvents through Filled Natural Rubber

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Isaac O. Igwe ◽  
Obumneme E. Ezeani
Keyword(s):  
Particle Size ◽  
Weight Gain ◽  
Natural Rubber ◽  
Activation Energies ◽  
Free Energies ◽  
Snail Shell ◽  
Aromatic Solvents ◽  
Benzene Toluene ◽  
Powder Content ◽  
Shell Powder

The transport of three aromatic solvents (benzene, toluene and xylene) through snail shell powder filled natural rubber was studied at 313, 333, and 353 K by conventional weight-gain experiments. The effects of snail shell powder content, particle size, nature of solvent, and temperature on the transport characteristics of natural rubber were determined. The estimated Arrhenius activation energies for the processes of sorption, diffusion, and permeation showed that the activation energies were highest in xylene at all the filler contents investigated. The calculated enthalpies, and entropies of sorption were all positive for the solvents investigated. Similarly, the change in the estimated free energies of sorption were all positive; an indication of the non-spontaneity of the solubility of snail shell powder filled natural rubber in the aromatic solvents at 313 k.

scholarly journals Studies on Mechanical and End-Use Properties of Natural Rubber Filled with Snail Shell Powder

2011 ◽  
Vol 02 (07) ◽  
pp. 801-809 ◽  
Author(s):  
Isaac Ogbennaya Igwe ◽  
Augustina Adanna Ejim
Keyword(s):  
Natural Rubber ◽  
Snail Shell ◽  
End Use ◽  
Shell Powder

scholarly journals Analysis of tensile strength, microstructure, and fractograph of Al-Si with snail shell powder as reinforce agent

2021 ◽  
Vol 1034 (1) ◽  
pp. 012131
Author(s):  
Poppy Puspitasari ◽  
Galy Dwi Susilo ◽  
Aminnudin ◽  
Yanuar Rohmat Aji Pradana ◽  
Andika Bagus Nur Rahma Putra ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Snail Shell ◽  
Shell Powder

Study on explosion suppression of coal dust with different particle size by shell powder and NaHCO3

Fuel ◽  
2021 ◽  
Vol 306 ◽  
pp. 121709
Author(s):  
Xiangrui Wei ◽  
Yansong Zhang ◽  
Guangan Wu ◽  
Xinyan Zhang ◽  
Yaqing Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Coal Dust ◽  
Explosion Suppression ◽  
Shell Powder

Influence of particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract parameters of broiler starters

2009 ◽  
Vol 49 (8) ◽  
pp. 704 ◽  
Author(s):  
A. M. Amerah ◽  
V. Ravindran
Keyword(s):  
Particle Size ◽  
Weight Gain ◽  
Digestive Tract ◽  
Feed Intake ◽  
Coarse Particle ◽  
Hammer Mill ◽  
Particle Sizes ◽  
Broiler Performance ◽  
Nutrient Utilisation ◽  
Microbial Phytase

The aim of the present experiment was to examine the interaction between particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract development of broiler starters fed maize-based diets. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two maize particle sizes (medium and coarse) and two levels of phytase supplementation (without or with 500 phytase units/kg diet). The two particle sizes were achieved by grinding the whole maize in a hammer mill to pass through 3- and 7-mm screens, respectively. Broiler starter diets, based on maize and soybean meal, were formulated to meet recommended requirements for major nutrients, except phosphorus. Each of the four diets was fed ad libitum to six pens of eight male broilers each, from day 1 to day 21 post-hatching. Phytase supplementation increased (P < 0.001) the feed intake and weight gain, and lowered (P < 0.05) feed per gain in both medium and coarse particle size diets. Coarse grinding improved (P < 0.05) weight gain, but had no effect (P > 0.05) on feed intake and feed per gain. No interactions (P > 0.05) between phytase supplementation and particle size were observed for any of the performance parameters. Phytase supplementation increased (P < 0.001) ileal phosphorus digestibility and toe ash content of birds fed the medium particle size diet, but had no effect in those fed the coarse particle size diet. Apparent metabolisable energy and ileal digestibility of calcium and nitrogen were not influenced by particle size or phytase supplementation. The present findings suggest that the effectiveness of supplemental phytase on broiler performance is not influenced by the particle size of maize.

Pyrolysis of Methane to Higher Hydrocarbons: A Thermodynamic Study

1989 ◽  
Vol 42 (10) ◽  
pp. 1655 ◽  
Author(s):  
FP Larkins ◽  
AZ Khan
Keyword(s):  
Gas Phase ◽  
Pressure Range ◽  
Solid Carbon ◽  
Free Energies ◽  
Oxidation Of Methane ◽  
Conversion Of Methane ◽  
Equilibrium Conversion ◽  
Benzene Toluene ◽  
Higher Hydrocarbons ◽  
The Individual

Some basic thermodynamic parameters such as Gibbs free energies, enthalpies of reactions and equilibrium compositions of products from the pyrolysis and partial oxidation of methane to higher hydrocarbons in the gas phase have been determined within a consistent framework for the temperature range 800-1500 K and the pressure range 0.1-3 MPa , by using the CSIRO-SGTE THERMODATA system. It has been established that the pyrolysis of methane to higher hydrocarbons, e.g. acetylene, ethylene, ethane, prop-1-ene, propane, benzene, toluene, naphthalene, 1-methylnaphthalene and 2-methylnaphthalene, considered as separate reactions, is a highly endothermic reaction with the Gibbs free energies for the individual reactions being positive until 1300 K. The aromatics are thermodynamically most favoured with the equilibrium yields increasing with temperature. Addition of O2 lowers the heats of synthesis and the free energies for methane conversion but no enhancement in the equilibrium yields of hydrocarbons is observed. When solid carbon is allowed, it is the dominant product in all cases with the equilibrium yields for all hydrocarbons becoming negligible. Increasing the pressure at a particular temperature has more effect on the lowering of the equilibrium conversion of methane than on the suppression of solid carbon. Such data are valuable for understanding the conversion limits for methane into higher hydrocarbons.

Effect of Vulcanization Temperature and Different Fillers on the Properties of Efficiently Vulcanized Natural Rubber

1979 ◽  
Vol 52 (2) ◽  
pp. 263-277 ◽  
Author(s):  
R. Mukhopadyay ◽  
S. K. De
Keyword(s):  
Particle Size ◽  
Natural Rubber ◽  
Crosslinking Density ◽  
Filler Loading ◽  
Zinc Stearate ◽  
Curing Temperature ◽  
Abnormal Behavior ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reinforcing Fillers

Abstract The present work deals with effect of vulcanization temperature on the polymer-filler interaction parameter, vulcanizate structure, and the technical properties of efficiently vulcanized natural rubber stocks in the presence of different fillers. We have used carbon blacks of four different particle sizes (ISAF, HAF, SRF, FT), reinforcing silica, and whiting. In the case of black fillers, as the particle size increases, reversion resistance increases. For all fillers, an increase of curing temperature from 150 to 180°C caused a reduction in strength, modulus, hardness, resilience; and an increase in elongation at break, compression set, and heat build-up. However, the flexing properties and abrasion loss showed improvement at higher curing temperature. Kraus' plots indicate that increase of curing temperature caused reduction in polymer-filler attachment. At both curing temperatures, the activity of fillers follow the order, ISAF &gt; HAF &gt; SRF &gt; FT. Silica showed erratic behavior in that Kraus plots indicate nonreinforcement by the filler. Whiting also behaved abnormally with respect to Kraus plots; at lower filler loading, the system is nonadherent, becoming weakly adherent at higher concentrations. The abnormal behavior of silica-filled compounds has been explained on the basis of a reaction on the silica surface between silanol groups and zinc stearate. Westlinning and Wolff's αF values were found to be independent of curing temperature and characteristic of fillers only (the larger the particle size, the lower is the αF value). The increase in apparent crosslinking density in the case of reinforcing fillers is due to increased υr arising out of increased polymer-filler interaction. Therefore, the sulfur inefficiency parameters (E values) and zinc sulfide efficiency parameters (F values) become less significant in filled vulcanizates.

Effect of graphene oxide particle size on the tensile strength and stability of natural rubber graphene composite

2020 ◽  
Vol 262 ◽  
pp. 114762
Author(s):  
Lai Peng Lim ◽  
Joon Ching Juan ◽  
Nay Ming Huang ◽  
Leng Kian Goh ◽  
Fook Peng Leng ◽  
...  
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Natural Rubber ◽  
Oxide Particle ◽  
Graphene Composite ◽  
Oxide Particle Size
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