Manipulating Solid-Surface Properties with Polymeric Agents

1991 ◽  
Vol 249 ◽  
Author(s):  
H. Watanabe ◽  
S.S. Patel ◽  
J.F. Argillier ◽  
E.E. Parsonage ◽  
J. Mays ◽  
...  
Keyword(s):  
Surface Density ◽  
Stable State ◽  
Adsorbed Layer ◽  
Water Soluble ◽  
Interaction Forces ◽  
Interaction Range ◽  
Interparticle Potential ◽  
Copolymer Structure ◽  
The Relationship ◽  
Characteristic Measure

ABSTRACTColloidal processing offers a way to minimize undesired heterogeneities in the fabrication of advanced ceramics. Stable dispersions can be created by manipulation of interparticle potential. Adsorption of diblock copolymer amphiphiles provides a way to obtain long range repulsive interactions between particles, at comparatively low polymer coverage, thereby enabling suspension stabilization. In this study we investigate the relationship between copolymer structure and adsorbed layer characteristics, and specifically, the nature and range of interactions. We find that the surface density and interaction range are governed by a characteristic measure of the copolymer asymmetry. In the case of copolymers where one of the blocks is ionic, and therefore water soluble, we find a hysteresis in the interaction forces, indicating a meta-stable state of the polymer layer.

scholarly journals Associating Polymer Networks Based on Cyclodextrin Inclusion Compounds for Heavy Oil Recovery

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xi Li ◽  
Zheng Shu ◽  
Pingya Luo ◽  
Zhongbin Ye
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Polymer Networks ◽  
Adsorbed Layer ◽  
Water Soluble ◽  
Heavy Oil Recovery ◽  
Original Oil In Place ◽  
Hydrolyzed Polyacrylamide ◽  
The Relationship ◽  
Associating Polymer

This work evaluates an approach to improve the enhanced heavy oil recovery performance of hydrophobic associating polymer. A polymeric system based on water-soluble hydrophobic associating polymer (WSHAP) and cyclodextrin (CD) polymer was proposed in this work. Addition of CD polymer to WSHAP forms interpolymer bridges by inclusion of CD groups with hydrophobic tails, and thereby the network structure is strengthened. The proposed system offers good viscoelasticity, pronounced shear thinning, and interesting viscosity-temperature relations. Sand pack tests indicated that the proposed system can build high resistance factor during the propagation in porous media, and its moderate adsorption phenomenon was represented by the thickness of the adsorbed layer. The relationship between effective viscosity and oil recovery increment indicated that the proposed system can significantly reduce the residual oil saturation due to the “piston-like” propagation. The overall oil recovery was raised by 5.7 and 24.5% of the original oil in place compared with WSHAP and partially hydrolyzed polyacrylamide (HPAM), respectively.

Evolutionary game analysis of information sharing by institutional investors

2021 ◽  
pp. 1-9
Author(s):  
Hua Li ◽  
Qingqing Lou ◽  
Qiubai Sun ◽  
Bowen Li
Keyword(s):  
Information Sharing ◽  
Institutional Investors ◽  
Information Exchange ◽  
Evolutionary Game ◽  
Stable State ◽  
Point Of View ◽  
Game Model ◽  
Game Analysis ◽  
Relationship Network ◽  
The Relationship

In order to solve the conflict of interests of institutional investors, this paper uses evolutionary game model. From the point of view of information sharing, this paper discusses four different situations. Only when the sum of risk and cost is less than the penalty of free riding, the evolution of institutional investors will eventually incline to the stable state of information sharing. That is, the phenomenon of hugging. The research shows that the institutional investors are not independent of each other, but the relationship network of institutional investors for the purpose of information exchange. The content of this paper enriches the research on information sharing of institutional investors.

scholarly journals Experimental study of the interaction range and association rate of surface-attached cadherin 11

1998 ◽  
Vol 95 (16) ◽  
pp. 9256-9261 ◽  
Author(s):  
Anne Pierres ◽  
Hélène Feracci ◽  
Véronique Delmas ◽  
Anne-Marie Benoliel ◽  
Jean-Paul Thiery ◽  
...  
Keyword(s):  
Adhesion Molecules ◽  
Bond Formation ◽  
Slow Motion ◽  
Classical Type ◽  
Association Rate ◽  
Interaction Range ◽  
A Cell ◽  
Coated Surfaces ◽  
The Relationship

We describe a method allowing quantitative determination of the interaction range and association rate of individual surface-attached molecules. Spherical beads (1.4 μm radius) were coated with recombinant outer domains of the newly described classical type II cadherin 11, a cell adhesion molecule. Beads were driven along cadherin-coated surfaces with a hydrodynamic force of ≈1 pN, i.e., much less than the mechanical strength of many ligand-receptor bonds. Spheres displayed periods of slow motion interspersed with arrests of various duration. Particle position was monitored with 50 Hz frequency and 0.025 μm accuracy. Nearly 1 million positions were recorded and processed. Comparison between experimental and computer-simulated trajectories suggested that velocity fluctuations might be related quantitatively to Brownian motion perpendicular to the surface. The expected amplitude of this motion was of order of 100 nm. Theoretical analysis of the relationship between sphere acceleration and velocity allowed simultaneous determination of the wall shear rate and van der Waals attraction between spheres and surface. The Hamaker constant was estimated at 2.9 × 10−23 J. The frequency of bond formation was then determined as a function of sphere velocity. Experimental data were consistent with the view that the rate of association between a pair of adhesion molecules was ≈1.2 × 10−3 s−1 and the interaction range was ≈10 nm. It is concluded that the presented methodology allows sensitive measurement of sphere-to-surface interactions (with ≈10 fN sensitivity) as well as the effective range and rate of bond formation between individual adhesion molecules.

On the 3D Correlation between Myofibroblast Shape and Contraction

2021 ◽  
Author(s):  
Alex Khang ◽  
Emma Lejeune ◽  
Ali Abbaspour ◽  
Daniel Howsmon ◽  
Michael Sacks
Keyword(s):  
Cell Shape ◽  
Interstitial Cell ◽  
Stable State ◽  
Stress Fiber ◽  
Poly Ethylene Glycol ◽  
Critical Feature ◽  
Peg Hydrogels ◽  
Poly Ethylene ◽  
And Function ◽  
The Relationship

Abstract Cell shape is known to correlate closely with stress-fiber geometry and function, and is thus a critical feature of cell biophysical state. However, the relationship between myofibroblast shape and contraction is complex, even as well in regards to steady-state contractile level (basal tonus). At present, the relationship between myofibroblast shape and basal tonus in 3D is poorly understood. Herein, we utilize the aortic valve interstitial cell (AVICs) as a representative myofibroblast to investigate the relationship between basal tonus and overall cell shape. AVICs were embedded within 3D poly (ethylene glycol) (PEG) hydrogels containing degradable peptide crosslinkers, adhesive peptide sequences, and sub-micron fluorescent micro-spheres to track the local displacement field. We then developed a methodology to evaluate the correlation between overall AVIC shape and basal tonus induced contraction. We computed a volume averaged stretch tensor <U> for the volume occupied by the AVIC, which had three distinct eigenvalues (1.08, 0.99, and 0.89), suggesting that AVIC shape is a result of anisotropic contraction. Furthermore, the direction of maximum contraction correlated closely with the longest axis of a bounding ellipsoid enclosing the AVIC. As gel--imbedded AVIC are known to be in a stable state by three days of incubation used herein, this finding suggests that the overall quiescent AVIC shape is driven by the underlying stress-fiber directional structure and possibly contraction level.

Flow of Hydrophobically Modified Water-Soluble-Polymer Solutions in Porous Media: New Experimental Insights in the Diluted Regime

SPE Journal ◽  
2010 ◽  
Vol 16 (01) ◽  
pp. 43-54 ◽  
Author(s):  
Guillaume Dupuis ◽  
David Rousseau ◽  
René Tabary ◽  
Bruno Grassl
Keyword(s):  
Oil Recovery ◽  
Polymer Concentration ◽  
Adsorbed Layer ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Improved Oil Recovery ◽  
Water Soluble Polymers ◽  
Resistance Factors ◽  
Soluble Polymers ◽  
Hydrophobically Modified

Summary The specific molecular structure of hydrophobically modified water-soluble polymers (HMWSPs), also called hydrophobically associative polymers, gives them interesting thickening and surface-adsorption abilities compared with classical water-soluble polymers (WSPs), which could be useful in polymer-flooding and well-treatment operations. However, their strong adsorption obviously can impair their injectivity, and, conversely, the shear sensitivity of their gels can be detrimental to well treatments. Determining for which improved-oil-recovery (IOR) application HMWSPs are best suited, therefore, remains difficult. The aim of this work is to bring new insight regarding the interaction mechanisms between HMWSPs and rock matrix and the consequences concerning their propagation in reservoirs. A consistent set of HMWSPs with sulfonated polyacrylamide backbones and alkyl hydrophobic side chains together with an equivalent WSP was synthesized and fully characterized. HMWSP and WSP solutions were then injected in model granular packs. As expected, with HMWSPs, high resistance factors (or mobility reductions, Rm) were observed. Yet, within the limit of the injected volumes, the effluent showed the same viscosity and polymer concentration as the injected solutions. A first significant outcome concerns the specificities of the Rm curves during HMWSP injections. Rm increases took place in two steps. The first corresponded to the propagation of the viscous front, as observed with WSP, whereas the second was markedly delayed, occurring several pore volumes (PV) after the breakthrough. This result is not compatible with the classical picture of multilayer adsorption of HMWSPs but suggests that injectivity is controlled solely by the adsorption of minor polymeric species. This hypothesis was confirmed by reinjecting the collected effluents into fresh cores; no second-step Rm increases were observed. Brine injections in HMWSP-treated cores revealed high residual resistance factors (or irreversible permeability reductions, Rk), which can be attributed to the presence of thick polymer-adsorbed layers on the pore surface. Nevertheless, Rk values strongly decreased when increasing the brine-flow rate. This second significant outcome shows that the adsorbed-layer thickness is shear-controlled. These new results should lead to proposing new adapted filtration and injection procedures for HMWSPs, aimed, in particular, at improving their injectivity.

scholarly journals Pendulum with aerodynamic and viscous damping

2020 ◽  
Vol 3 (2) ◽  
pp. 43-47
Author(s):  
Herlin Soraya
Keyword(s):  
Differential Equations ◽  
Stable State ◽  
The State ◽  
Linear Differential Equations ◽  
Viscous Damping ◽  
Viscous Damper ◽  
Aerodynamic Damping ◽  
Non Linear ◽  
Linear Differential ◽  
The Relationship

In this paper we discuss about how the relationship between non-linear differential equations on aerodynamic damping with linearly viscous damping equations. And it turns out after analyzing that the changes that occur pendulum that changes from the start of the maximum state to a stable state takes time so that changes that occur until the state is stable, this change can be reduced with the use of viscous damper

scholarly journals Highly Water-Soluble Solid Dispersions of Honokiol: Preparation, Solubility, and Bioavailability Studies and Anti-Tumor Activity Evaluation

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 573 ◽  
Author(s):  
Wang ◽  
Wu ◽  
Wang ◽  
Wang ◽  
Zhao
Keyword(s):  
Water Solubility ◽  
Solid Dispersions ◽  
Drug Formulation ◽  
Water Soluble ◽  
Oral Drug ◽  
Diphenyltetrazolium Bromide ◽  
Soluble Solid ◽  
Artificial Gastric Juice ◽  
The Relationship ◽  
Anti Tumor Activity

Honokiol (HK), a well-tolerated natural product, has many multiple pharmacological activities. However, its poor water solubility and low bioavailability limit its clinical application and development. The aim of this research was to prepare the solid dispersion (SD) formulation of honokiol (HK) with poloxamer-188 (PLX) as the carrier, thereby improving its solubility and oral bioavailability. Firstly, by investigating the relationship between the addition amount of the PLX and the solubility of HK, and the effects of solid dispersions with different ratios of HK–PLX on the solubility of HK, we determined that the optimum ratio of PLX to HK was (1:4). Then, the HK–PLX (1:4) SD of HK was prepared using the solvent evaporation method. The morphology of the obtained HK–PLX (1:4) SD was different from that of free HK. The HK in the HK–PLX (1:4) SD existed in amorphous form and formed intermolecular hydrogen bonds with PLX. Additionally, the solubility values of the HK–PLX (1:4) SD were about 32.43 ± 0.36 mg/mL and 34.41 ± 0.38 mg/mL in artificial gastric juice (AGJ) and in artificial intestinal juice (AIJ), respectively. Compared with free HK, the release rate and the bioavailability was also substantially improved for HK in its SD form. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that the HK–PLX (1:4) SD showed higher inhibition of HepG2 cells than free HK. Taken together, the present study suggests that the HK–PLX (1:4) SD could become a new oral drug formulation with high bioavailability and could produce a better response for clinical applications of HK.

Effects of Activated Sludge Properties on Water Flux of Ultrafiltration Membrane Used for Human Excrement Treatment

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1601-1608 ◽  
Author(s):  
Takeshi Sato ◽  
Yasuhiko Ishii
Keyword(s):  
Activated Sludge ◽  
Water Flux ◽  
Stable State ◽  
Transmembrane Pressure ◽  
Test Plant ◽  
Average Pressure ◽  
Filtration Resistance ◽  
State Water ◽  
Sludge Properties ◽  
The Relationship

We studied the relationship between water flux of a UF membrane with MLSS, soluble COD, and the viscosity of activated sludge suspension in a human excrement treatment test plant utilizing UF membrane. The bench-scale plate and frame UF membrane test unit was operated for activated sludge suspension of 20~29 kg/m3 MLSS, 500-730 g/m3 soluble COD and 0.38-1.3 Pa·s viscosity under the conditions of 0.2-0.24 MPa average pressure and 2 m/s recirculating velocity. As a result, stable-state water flux was 0.55-1.65 m/D at 25°C. The relationship between filtration resistance R to transmembrane pressure drop ∆P, MLSS, COD, and viscosity η was expressed by the following equation: From this equation, we were able to predict R with an accuracy of ±24%. Soluble COD had the largest effect on water flux followed by MLSS. The effect of viscosity was relatively small.

Tolerance of Birdsfoot Trefoil (Lotus corniculatus) to 2,4-D

Weed Science ◽  
1986 ◽  
Vol 34 (3) ◽  
pp. 373-376 ◽  
Author(s):  
Cynthia Davis ◽  
Dean L. Linscott
Keyword(s):  
Protein Synthesis ◽  
Lotus Corniculatus ◽  
Water Soluble ◽  
Side Chain ◽  
Birdsfoot Trefoil ◽  
Tolerance Mechanisms ◽  
Differential Binding ◽  
Dichlorophenoxy Acetic Acid ◽  
The Relationship ◽  
Soluble Components

Translocation and metabolism of14C-2,4-D [(2,4-dichlorophenoxy)acetic acid] and effects of 2,4-D on protein synthesis were compared in ‘T–68’ (2,4-D tolerant) and ‘Viking’ (susceptible) birdsfoot trefoil (Lotus corniculatusL.) in an attempt to elucidate some tolerance mechanisms. After14C-2,4-D was applied to upper trifoliate leaves, significantly less 2,4-D was found in stems, in leaves below the treated leaves, and in roots of T–68 compared to Viking. More 2,4-D was bound to alcohol-insoluble cellular constituents of T–68 leaves, stems, and roots. When alcohol-soluble components were fractionated, slightly more14C water-soluble compounds were found in T–68, indicating further inactivation by glycosylation. No amino acid-2,4-D conjugates were found. The rate of14CO2evolution from14C-2,4-D treated seedlings in T–68 was five times that in Viking. Protein synthesis appeared to be more rapid in T–68 but the relationship to 2,4-D was not clear. In part, 2,4-D resistance in T–68 may result from its ability to inactivate 2,4-D by differential binding and conjugation and by side chain breakdown as indicated by14CO2release.

Prediction of forage dry matter and soluble carbohydrate content from analysis of expressed juice

1996 ◽  
Vol 1996 ◽  
pp. 234-234
Author(s):  
D.I.H. Jones ◽  
C.P. Freeman ◽  
J.R. Newbold ◽  
A.R. Fychan ◽  
Elspeth Jones ◽  
...  
Keyword(s):  
Dry Matter ◽  
Carbohydrate Content ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Silage Fermentation ◽  
Ultimate Objective ◽  
Water Soluble Carbohydrate ◽  
On Farm ◽  
The Relationship

The dry matter (DM) and water soluble carbohydrate (WSC) concentrations of forage are the main characteristics influencing the course of silage fermentation. Knowledge of these parameters would enable decisions to be made both on the need for additive and the type of additive likely to be most effective. Moreover, the degree of wilt could also be followed in wilted crops. The present study was directed to assessing the relationship between the composition of the crop and the volume and composition of the expressed juice. The ultimate objective was the development of on-farm methodology for predicting the ensiling characteristics of crops.

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