scholarly journals Morphology and Rheological Properties of Polyacrylamide/Bentonite Organic Crosslinking Composite Gel

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3648
Author(s):  
Jun Li ◽  
Wen Zhou ◽  
Zhilin Qi ◽  
Taotao Luo ◽  
Wende Yan ◽  
...  
Keyword(s):  
Particle Size ◽  
Shear Stress ◽  
Crosslinking Agent ◽  
Shear Thinning ◽  
Polymer Gel ◽  
Water Control ◽  
Size Change ◽  
Start Up ◽  
Composite Gel ◽  
Crosslinker Content

The use of polymer gel for water control and oil addition is a common technical method in oilfield development. The polymer and hydrated bentonite react under the action of an organic crosslinking agent to form a composite gel. The particle-size change and microstructure of the composite gel were analyzed via shear thinning, thixotropic, viscoelastic, and start-up stress rheology experiments. The experimental results show that the polyacrylamide/bentonite organic crosslinked composite gel was a gel system with bentonite as the core aggregate structure, and the large particle-size distribution was mostly increased with increasing crosslinker content. The composite gel presented shear thinning characteristics, the content of bentonite or crosslinking agent was increased, and the shear resistance was stronger at a high shear rate. The composite gel exhibited positive thixotropic properties, and the thixotropy increased with increasing bentonite content. The composite gel had good viscoelastic characteristics, the elastic characteristics of the composite gel showed more significantly with bentonite increases, and the viscosity of the composite gel showed its characteristics more significantly with the crosslinking agent increased. After loading at a rate on the composite gel, the shear stress increased significantly with time and reached its maximum value, and then the shear stress decreased and gradually stabilized.

Physical and bacterial processes affecting suspended particulate matter in a tidal river

1998 ◽  
Vol 38 (6) ◽  
pp. 327-335
Author(s):  
Yasunori Kozuki ◽  
Yoshihiko Hosoi ◽  
Hitoshi Murakami ◽  
Katuhiro Kawamoto
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
River Mouth ◽  
Tidal River ◽  
Natural Soil ◽  
Size Change ◽  
Run Off ◽  
Suspended Particulate ◽  
And Behavior

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.

Investigation on the Rheological Behavior of Polyamide6/Montmorillonite Nanocomposites by Reactive Extrusion

2011 ◽  
Vol 233-235 ◽  
pp. 1998-2001 ◽  
Author(s):  
Ming Zhao ◽  
Xiao Zhong Lu ◽  
Kai Gu ◽  
Xiao Min Sun ◽  
Chang Qing Ji
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Reactive Extrusion ◽  
Shear Thinning ◽  
Experimental Results ◽  
Montmorillonite Nanocomposites

The rheological behavior of PA6/montmorillonite(MMT) by reactive extrusion was investigated using cone-and-plate rheometer. The experimental results indicated that PA6/MMT exhibited shear-thinning behavior. The shear stress of both neat PA6 and PA6/MMT increased with the increase in the shear rate. The reduction of the viscous activation energy with the increase of shear stress reflected PA6/MMT can be processed over a wider temperature.

scholarly journals Start-up shear flow of a shear-thinning fluid that approximates the response of viscoplastic fluids

2022 ◽  
Vol 412 ◽  
pp. 126571
Author(s):  
Sai Manikiran Garimella ◽  
Mohan Anand ◽  
Kumbakonam R. Rajagopal
Keyword(s):  
Shear Flow ◽  
Shear Thinning ◽  
Viscoplastic Fluids ◽  
Start Up ◽  
Shear Thinning Fluid

Numerical Analysis of Size Reduction of Municipal Solid Waste Particles on the Traveling Grate of a Waste-to-Energy Combustion Chamber

2006 ◽  
Author(s):  
Masato Nakamura ◽  
Marco J. Castaldi ◽  
Nickolas J. Themelis
Keyword(s):  
Particle Size ◽  
Municipal Solid Waste ◽  
Combustion Chamber ◽  
Solid Waste ◽  
Size Reduction ◽  
Waste To Energy ◽  
Size Change ◽  
Model Combining ◽  
Shrinking Core ◽  
Waste Particles

The size reduction of municipal solid waste (MSW) particles on the reverse acting traveling grate of a waste-to-energy (WTE) combustion chamber was estimated by means of a numerical model combining the particle size distributions (PSD) of MSW and combustion residues and the Shrinking Core Model (SCM). This new integrated model was used to simulate the particle behavior on the grate. During their travel on the moving grate, the sizes of the particles are reduced by combustion, breakage, and compaction. This study shows the calculation of the particle size change using this model and comparison of the numerically derived PSDs of MSW and ash particles with experimental data. There is good agreement between calculated and measured values.

Investigation of the Particle Size Change of a La(Ni, Fe)O3 as a Cathode

2019 ◽  
Vol 35 (1) ◽  
pp. 2313-2319 ◽  
Author(s):  
Yoshiteru Yoshida ◽  
Reiichi Chiba ◽  
T. Komatsu ◽  
Masayuki Yokoo ◽  
Katsuya Hayashi ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Change

Effect of Shear Stress on Granulation in Oxygen Aerobic Upflow Sludge Bed Reactors

1992 ◽  
Vol 26 (3-4) ◽  
pp. 601-605 ◽  
Author(s):  
H.-S. Shin ◽  
K.-H. Lim ◽  
H.-S. Park
Keyword(s):  
Shear Stress ◽  
Morphological Study ◽  
Loading Rate ◽  
Granular Sludge ◽  
Treatment Method ◽  
The Self ◽  
High Rate ◽  
Synthetic Wastewater ◽  
Filamentous Bacteria ◽  
Start Up

Aerobic upflow sludge blanket(AUSB) process is a new biological wastewater treatment method applying the concept of the self-immobilization to activated sludge. Two sets of AUSB system with different mixing velocities of 3 rpm(R1) and 6 rpm(R2) were operated for high-rate treatment of synthetic wastewater. The COD removal efficiency in R2 was higher than R1 at the same loading rate up to 7 kg/m3·day. However, in R1, the sludge bulking was observed at the end of the experiment. The chocolate colored granules were formed about 5 days after the start-up. The morphological study on the granular sludge consortia was made with both scanning electron and optical microscopes. The granules were 0.5-2.5 mm in diameter and mainly consisted of bacteria with pili-like appendages and filamentous bacteria, which were thought to be Sphaerotilus natans and Beggiatoa. In R1, the long multicellular filaments causing bulking were prevalent in the granule, while in R2 overgrowth of filamentous bacteria was prevented with appropriate shear stress resulting in higher MLSS density. Experimental results indicated that granulation could be controlled by physical stress on granular sludge.

scholarly journals Design of insulin-loaded alginate nanoparticles: Influence of the calcium ion on polymer gel matrix properties

2006 ◽  
Vol 12 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Catarina Reis ◽  
R.J. Neufeld ◽  
António Ribeiro ◽  
Francisco Veiga
Keyword(s):  
Particle Size ◽  
Calcium Ions ◽  
Oral Delivery ◽  
Encapsulation Efficiency ◽  
Particle Production ◽  
Calcium Salt ◽  
Mass Relation ◽  
Polymer Gel ◽  
Oil Emulsion ◽  
Water In Oil Emulsion

Alginate-based nanoparticles were produced by dispersing alginate aqueous solution containing an insoluble calcium salt within mineral oil forming a water-in-oil emulsion. Subsequently, alginate gelled upon contact with the calcium ions due to the physical cross-linking between the carboxylate anions of the alginate and the calcium ions. The influence of the calcium salt, added in varying amounts, on gel integrity and on particle size was investigated. The efficiency of encapsulating active biological compounds by nanoparticles was also assayed. The calcium concentration was seen to be a crucial parameter in particle production, influencing the particle size, the viscosity of the solutions at different stages of the emulsification/gelation process and, finally, the encapsulation efficiency. The most appropriate mass relation between calcium and alginate was 7% (w/w). Under this condition, the smallest mean diameter obtained was 2.604 ? 2.141 ?m combined with the narrowest range of particle sizes. The encapsulation efficiency of insulin was over 71 %. These previous characteristics appear to be best suited for producing small, well-dispersed and stable nanoparticles with high encapsulation of insulin. This particulate system may be considered as a promising carrier for the oral delivery of insulin.

Study on Incipient Motion of Consolidated Cohesive Fine Sediment

2012 ◽  
Vol 204-208 ◽  
pp. 354-358
Author(s):  
Jun Wang ◽  
Wei Guo ◽  
Hai Tao Xu ◽  
Zhong Wu Jin ◽  
Yin Jun Zhou
Keyword(s):  
Particle Size ◽  
Shear Stress ◽  
Critical Shear Stress ◽  
Fine Sediment ◽  
Weight Increase ◽  
Unit Weight ◽  
Incipient Motion ◽  
Mean Particle Size ◽  
Dry Unit Weight ◽  
The One

The incipient motion mechanism of cohesive fine sediment is different to the one of non-cohesive sediment. It is related to the consolidation while being influenced by the dry unit weight and particle size. By means of the rectangle piping flume, the influence mechanism of dry unit weight and particle size to critical shear stress of cohesive fine sediment is studied. Experimental results show that on the condition of consolidation, the influence of dry unit weight to incipient motion is divided into two different stages, one is that when dry unit weight increase quickly, but the influence to incipient motion is not greatly, another is that when dry unit weight increase slowly, but the influence to incipient motion is very greatly, the critical dry unit weight to two stages decline as mean particle size decrease. So the mean particle size is finer, the degree of dry unit weight influence to critical shear stress is stronger, and the incipient motion is more difficult when consolidation last longer; it is also shown consolidation is more disadvantageous to incipient motion.

Rheology and fluid loss of a polyacrylamide-based micro-gel particles in a water-based drilling fluid

2020 ◽  
Vol 10 (5) ◽  
pp. 657-662
Author(s):  
Gang Wang ◽  
Honghai Fan ◽  
Guancheng Jiang ◽  
Wanjun Li ◽  
Yu Ye ◽  
...  
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Drilling Fluid ◽  
Crosslinking Agent ◽  
Fluid Loss ◽  
Temperature Property ◽  
Water Based ◽  
The Cross

In this paper, the cross-linked micro-gel polymer between acrylamide (AM) and N, N-Methylenebisacrylamide (MBA) was synthesized by dispersion polymerization. The initiator and crosslinking agent concentration were used to control the particle size of micro-gel polymer. The filtration property and mechanism of micro-gel were investigated comprehensively. The characteristics of micro-gel were checked by means of Fourier transform infrared spectroscopy, thermogravimetry, transmission electron microscopy, and particle size distribution, respectively. The results indicated that the cross-linked micro-gel polymer exhibited several outstanding merits, such as thermal stability (up to 200 °C), filtration control and rheological property. Microstructure analysis and particle size distribution examinations showed that the scale of micro-gel polymer was micro, which is in accord with design. Rheological tests demonstrated that the nonlinear structure of micro-gel polymer showed less impact on the apparent viscosity. The anti-high temperature property of micro-gel polymer was better than poly anioniccellulose (PAC) and asphalt widely applied in drilling fluid for anti-high temperature fluid-loss additive. As a result, the cross-linked micro-gel polymer had great potential to be applied in high temperature water-based mud.

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