The effect of recycled polymer addition on the thermorheological behavior of modified lubricating greases

2012 ◽  
Vol 53 (4) ◽  
pp. 818-826 ◽  
Author(s):  
J.E. Martín-Alfonso ◽  
C. Valencia ◽  
M.C. Sánchez ◽  
J.M. Franco ◽  
C. Gallegos
Keyword(s):  
Polymer Addition ◽  
Thermorheological Behavior ◽  
Recycled Polymer

The Use of Rheology for Sludge Characterization

1982 ◽  
Vol 14 (6-7) ◽  
pp. 475-489 ◽  
Author(s):  
H W Campbell ◽  
P J Crescuolo
Keyword(s):  
Particle Size ◽  
Sewage Sludge ◽  
Test Procedures ◽  
Particle Size Reduction ◽  
Rotational Viscometer ◽  
Polymer Addition ◽  
Rheological Measurements ◽  
Acceleration Rate ◽  
Sludge Characterization ◽  
Potential Use

Rheological measurements were conducted on a variety of anaerobically digested sewage sludges to evaluate the potential use of rheology in describing the effects of chemical conditioning on the physical characteristics of sludges. The objectives of the study were to evaluate the influence of the method of chemical conditioning on rheological measurements; to determine the response of the viscometer system to changes in the instrument variables; and to evaluate interrelationships between rheology and other physical properties. All rheological measurements were made using a coaxial rotational viscometer. Evaluation of a variety of test procedures identified that both the method of adding chemical conditioners, and the acceleration rate of the rotational viscometer, could significantly alter the shape of the rheograms. A suggested methodology was identified and selected samples were analyzed in triplicate to test the reproducibility of the procedures. Existing mathematical models do not adequately describe the variety of flow behaviour patterns observed with sewage sludge. The concepts of yield stress and apparent viscosity also have limited value due to problems of definition and calculation. A parameter termed the “instantaneous viscosity”, defined as the derivative of the flow curve, is suggested as being more suitable for describing sludge behaviour. The relationships between chemical conditioning, particle size distribution and applied shear were explored. As polymer addition increased, the sludge particles became more susceptible to shear breakup. The extent of particle size reduction was a function of the rate of shear and the time during which the shear was maintained.

Solvent recycling of polypropylene: 1. Properties of the recycled polymer

Polymer ◽  
1979 ◽  
Vol 20 (3) ◽  
pp. 333-336 ◽  
Author(s):  
W.R. Murphy ◽  
M.S. Otterburn ◽  
J.A. Ward
Keyword(s):  
Recycled Polymer

Effect of surfactant on alum sludge conditioning and dewaterability

2000 ◽  
Vol 41 (8) ◽  
pp. 17-22 ◽  
Author(s):  
J. Ruhsing Pan ◽  
C. Huang ◽  
C. Gang Fu
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Flotation Process ◽  
Polymer Addition ◽  
Sludge Disposal ◽  
Alum Sludge ◽  
Sludge Conditioning ◽  
Increasing Demand ◽  
Co Precipitation

Sludge disposal has become a new challenge for the Taiwan government due to the increasing demand for better quality and greater quantity of water. In some water treatment plants, surfactant has been applied in the flotation process to improve its performance, which suggests the use of surfactant in sludge conditioning. In this study, effects of surfactants on the conditioning of the alum sludge collected from Feng-Yuan Water Treatment Plant were investigated. Surfactants of various charges, namely CTAB and SDS, were added to sludge samples in various amounts, and their effects on sludge dewaterability were evaluated. Surfactants were also added with either cationic or anionic polymers to better understand their effects on the mechanism of sludge conditioning and the feasibility as coagulant aid.Experimental results indicate that applying surfactants alone in sludge system decrease the filterability of sludge, but increase the sludge dewatering rate at optimum dosage. Cationic surfactant was proven possible as conditioning aid for the cationic polymer. The order of surfactant and polymer addition is the key to additive function. On the other hand, when the polymer of opposite charge was added with the surfactant, co-precipitation occurred which resulted in decreased filterability and dewaterability.

scholarly journals Hydration and Microwave Curing Temperature Interactions of Repair Mortars

2021 ◽  
Vol 03 (04) ◽  
pp. 1-1
Author(s):  
Pal S. Mangat ◽  
◽  
Shahriar Abubakri ◽  
Konstantinos Grigoriadis ◽  
Vincenzo Starinieri ◽  
...  
Keyword(s):  
Portland Cement ◽  
Heat Of Hydration ◽  
Curing Temperature ◽  
Early Age ◽  
Normal Density ◽  
Concrete Repair ◽  
Microwave Curing ◽  
Polymer Addition ◽  
Curing Period ◽  
Repair Materials

Microwave curing of repair patches provides an energy efficient technique for rapid concrete repair. It has serious economic potential due to time and energy saving especially for repairs in cold weather which can cause work stoppages. However, the high temperatures resulting from the combination of microwave exposure and accelerated hydration of cementitious repair materials need to be investigated to prevent potential durability problems in concrete patch repairs. This paper investigates the time and magnitude of the peak hydration temperature during microwave curing (MC) of six cement based concrete repair materials and a CEM II mortar. Repair material specimens were microwave cured to a surface temperature of 40-45 °C while their internal and surface temperatures were monitored. Their internal temperature was further monitored up to 24 hours in order to determine the effect of microwave curing on the heat of hydration. The results show that a short period of early age microwave curing increases the hydration temperature and brings forward the peak heat of hydration time relative to the control specimens which are continuously exposed to ambient conditions (20 °C, 60% RH). The peak heat of hydration of normal density, rapid hardening Portland cement based repair materials with either pfa or polymer addition almost merges with the end of microwave curing period. Similarly, lightweight polymer modified repair materials also develop heat of hydration rapidly which almost merges with the end of microwave curing period. The peak heat of hydration of normal density ordinary Portland cement based repair materials, with and without polymer addition, occurs during the post microwave curing period. The sum of the microwave curing and heat of hydration temperatures can easily exceed the limit of about 70 °C in some materials at very early age, which can cause durability problems.

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