Reduction of Surfactant Retention in Limestones Using Sodium Hydroxide

SPE Journal ◽  
2018 ◽  
Vol 24 (01) ◽  
pp. 92-115 ◽  
Author(s):  
D.. Wang ◽  
M.. Maubert ◽  
G. A. Pope ◽  
P. J. Liyanage ◽  
S. H. Jang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Sodium Hydroxide ◽  
Anionic Surfactants ◽  
Geochemical Modeling ◽  
Low Molecular Weight ◽  
Low Concentrations ◽  
Reservoir Conditions ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Indiana Limestone

Summary Geochemical modeling was used to design and conduct a series of alkaline/surfactant/polymer (ASP) coreflood experiments to measure the surfactant retention in limestone cores using sodium hydroxide (NaOH) as the alkali. Surfactant/polymer (SP) coreflood experiments were conducted under the same conditions for comparison. NaOH has been used for ASP floods of sandstones, but these are the first experiments to test it for ASP floods of limestones. Two studies performed under different reservoir conditions showed that NaOH significantly reduced the surfactant retention in Indiana Limestone. An ASP solution with 0.3 wt% NaOH has a pH of approximately 12.6 at 25°C. The high pH increases the negative surface charge of the carbonate, which favors lower adsorption of anionic surfactants. Another advantage of NaOH is that low concentrations of only approximately 0.3 wt% can be used because of its low molecular weight and its low consumption in limestones. Most reservoir carbonates contain gypsum or anhydrite, and therefore sodium carbonate (Na2CO3) will be consumed by the precipitation of calcium carbonate (CaCO3). As shown in the two studies, NaOH can be used in limestone reservoirs containing gypsum or anhydrite.

scholarly journals Effects of Chitosan onCandida albicans: Conditions for Its Antifungal Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Antonio Peña ◽  
Norma Silvia Sánchez ◽  
Martha Calahorra
Keyword(s):  
Yeast Cells ◽  
Low Molecular Weight ◽  
Extracellular Acidification ◽  
Pathogenic Yeast ◽  
Inhibition Of Growth ◽  
Low Concentrations ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
High Concentrations ◽  
Transmembrane Potential Difference

The effects of low molecular weight (96.5 KDa) chitosan on the pathogenic yeastCandida albicanswere studied. Low concentrations of chitosan, around 2.5 to 10 μg·mL−1produced (a) an efflux of K+and stimulation of extracellular acidification, (b) an inhibition of Rb+uptake, (c) an increased transmembrane potential difference of the cells, and (d) an increased uptake of Ca2+. It is proposed that these effects are due to a decrease of the negative surface charge of the cells resulting from a strong binding of the polymer to the cells. At higher concentrations, besides the efflux of K+, it produced (a) a large efflux of phosphates and material absorbing at 260 nm, (b) a decreased uptake of Ca2+, (c) an inhibition of fermentation and respiration, and (d) the inhibition of growth. The effects depend on the medium used and the amount of cells, but in YPD high concentrations close to 1 mg·mL−1are required to produce the disruption of the cell membrane, the efflux of protein, and the growth inhibition. Besides the findings at low chitosan concentrations, this work provides an insight of the conditions required for chitosan to act as a fungistatic or antifungal and proposes a method for the permeabilization of yeast cells.

Low concentrations of intravenous polygelines promote low-molecular weight proteinuria

2003 ◽  
Vol 33 (11) ◽  
pp. 962-968 ◽  
Author(s):  
B. A. J. Veldman ◽  
H. L. E. Schepkens ◽  
G. Vervoort ◽  
I. Klasen ◽  
J. F. M. Wetzels
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Low Molecular Weight Proteinuria ◽  
Low Concentrations

The effect of a Rhizoctonia solani phytotoxin on potatoes

1976 ◽  
Vol 54 (22) ◽  
pp. 2536-2540 ◽  
Author(s):  
J. A. Frank ◽  
S. K. Francis
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Rhizoctonia Solani ◽  
Liquid Culture ◽  
Phenylacetic Acid ◽  
Low Molecular Weight ◽  
Leaf Margin ◽  
Disease Symptoms ◽  
Low Concentrations ◽  
Root Necrosis

Rhizoctonia solani produces a nonenzymatic, low-molecular-weight phytotoxin in liquid culture. Many of the disease symptoms on potato attributed to this pathogen can be induced with this toxin. These include root necrosis and stolon pruning, leaf curling, stunting, and leaf margin chlorosis. In cases of extreme susceptibility, the plants could be killed within 1 week. The toxin has similar effects on radish, beet, and corn seedlings and acts as a growth hormone in low concentrations. A technique was designed to evaluate potato clones for their resistance to the root necrosis phase of the disease syndrome. With additional purification, the toxic fraction was identified as phenylacetic acid and its metahydroxylated derivative.

scholarly journals Surface properties related to concanavalin A-induced agglutination. A comparative study of several Entamoeba strains.

1977 ◽  
Vol 145 (3) ◽  
pp. 652-665 ◽  
Author(s):  
D Trissl ◽  
A Martínez-Palomo ◽  
C Argüello ◽  
M de la Torre ◽  
R de la Hoz
Keyword(s):  
Surface Properties ◽  
Concanavalin A ◽  
Room Temperature ◽  
Lectin Binding ◽  
Cationized Ferritin ◽  
Con A ◽  
Low Concentrations ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Axenic Strains

Pathogenic strains of Entamoeba histolytica are more easily agglutinated with concanavalin A (Con A) than strains isolated from human asymptomatic carriers. All three pathogenic strains studied here were found to agglutinate with low concentrations of Con A in contrast to various nonpathogenic axenic strains of amebas, characterized by their ability to grow at room temperature. Our present observations suggest that the extreme susceptibility of pathogenic strains of E. histolytica to agglutinate with Con A is related to their higher capacity for lectin binding and to their lack of detectable repulsive charges at the cell surface. The amount of fluorescein-tagged Con A bound to the surface was much higher in pathogenic strains. Only nonpathogenic strains showed a detectable negative surface charge as studied both by means of cell microelectrophoresis and by labeling cells with cationized ferritin at 0 degrees C. The mobility of surface Con A receptors estimated as the percentage of caps was comparable in all strains. Results of one strain cultured in axenic and monoxenic conditions suggested that bacteria can modify the behaviour of E. histolytica trophozoites by altering surface properties of the amebas.

HIGH CONCENTRATIONS OF HEPARIN ARE MORE INHIBITORY TO PLATE- AGGREGATION IN-VITRO THAN ARE LOW MOLECULAR WEIGHT HEPARINS AND HEPARINOIDS AT THE SAME CONCENTRATION

1987 ◽  
Author(s):  
H Messmore ◽  
B Griffin ◽  
J Seghatchian ◽  
E Coyne
Keyword(s):  
Molecular Weight ◽  
Heparan Sulfate ◽  
Dermatan Sulfate ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Low Molecular Weight ◽  
Low Concentrations ◽  
High Concentrations ◽  
Induced Aggregation

Other investigators have shown that heparin in the usual therapeutic range (0.1-0.5 units/ml) has an enhancing effect on ADP aggregation and an inhibitory effect on collagen and thrombin induced aggregation. The effects of low molecular weight heparin (LMWH)and heparinoids (dermatan sulfate, heparan sulfate) on platelet aggregation have not been as extensivelystudied. We have utilized citrated platelet rich plasma (3.2%citrate-whole blood 1:9) drawn in plastic and adjusted to a final platelet count of 250,000/ul. A Bio-Data 4 channgl aggregometer was utilized with constantstirring at 37 C. The reaction was allowed to run for 20 minutes. Platelet rich plasma was supplemented 1:9 with saline or heparin and various agonists were then added ifno aggregation occurred. ADP, collagen, thrombin, ristocetin and serum from patients with heparin inudced thrombocytopenia (HIT) were utilized as agonists. Heparin was substituted at concentrations of 0.1 to 500 units per ml and various LMWH and heparinoids were substituted in equivalent anti-Xa or gravimetric concentrations. At low concentrations no inhibitory effect on any ofthe agonists was observed with any of the heparins or heparinoids. At concentrations of heparin of 100 u/ml or greater, all agonists were inhibited. At equivalent concentrations of five different LMWH (Cy 216, Cy 222, Pk 10169, Kabi 2165 and pentasaccharide) inhibition did notoccur at all or at very high concentions only. Dermatan sulfate and heparan sulfate inhibited only at high concentrations. HIT serum could not aggregate platelets with dermatan sulfate or pentasaccharide atany concentrations, but it was a good agonist with the other heparins and heparinoids.

scholarly journals Inhibition of adenosine triphosphatase, 5-hydroxytryptamine transport and proton-translocation activities of resealed chromaffin-granule ‘ghosts’

1980 ◽  
Vol 190 (2) ◽  
pp. 273-282 ◽  
Author(s):  
David K. Apps ◽  
James G. Pryde ◽  
Raul Sutton ◽  
John H. Phillips
Keyword(s):  
Molecular Weight ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Proton Translocation ◽  
Low Molecular Weight ◽  
Chromaffin Granule ◽  
Low Concentrations ◽  
Tributyltin Chloride ◽  
Granule Membrane ◽  
Chromaffin Granule Ghosts

1. Highly purified resealed chromaffin-granule ‘ghosts’ were assayed for ATPase and ATP-driven H+-translocation and 5-hydroxytryptamine-uptake activities, and for 5-hydroxytryptamine uptake driven by an imposed transmembrane H+-gradient. The effects of several inhibitors on these activities were studied. 2. Dicyclohexylcarbodi-imide inhibits all of these activities, but not in parallel; at low concentrations it decreases the permeability of the membrane to protons. 3. 4-Chloro-7-nitrobenzofuran (Nbf-Cl) and silicotungstate inhibit ATP-dependent activities, without effect on 5-hydroxytryptamine uptake driven by an imposed H+-gradient. 4. Tributyltin chloride inhibits all of the activities. 5. Treatment of the ‘ghosts’ with low concentrations of urea inhibits 5-hydroxytryptamine uptake and ATP-dependent generation of a transmembrane H+-gradient, without inhibiting ATPase activity. 6. Nbf-Cl and silicotungstate are without effect on the rate of leakage of 5-hydroxytryptamine from preloaded ‘ghosts’, whereas dicyclohexylcarbodi-imide and tributyltin chloride accelerate the rate of leakage. 7. Treatment of the membranes with 14C-labelled Nbf-Cl labels several proteins; membranes treated with dicyclohexyl[14C]carbodi-imide are labelled predominantly in a protein of low molecular weight, which may be analogous to the mitochondrial H+-conducting proteolipid. 8. It is concluded that Nbf-Cl and silicotungstate inhibit the H+-translocating ATPase of the granule membrane; that dicyclohexylcarbodi-imide inhibits the ATPase, and inhibits 5-hydroxytryptamine accumulation by accelerating leakage of the amine; and that the effects of tributyltin chloride are due to inhibition of the ATPase, and collapse of the transmembrane H+-gradient through OH−-anion exchange.

Carboxymethy Chitosan Grafted Ricinoleic Acid Group for Nanopesticide Carriers

2011 ◽  
Vol 236-238 ◽  
pp. 1783-1788 ◽  
Author(s):  
Bo Hua Feng ◽  
Zi Yong Zhang
Keyword(s):  
Molecular Weight ◽  
Surface Charge ◽  
Ricinoleic Acid ◽  
Spherical Shape ◽  
Acid Group ◽  
Polydispersity Index ◽  
Surface Shape ◽  
Botanical Insecticide ◽  
Negative Surface ◽  
Negative Surface Charge

A new chitosan derivate (CMC-g-RA) was prepared by grafting ricinoleic acid anhydride (RA) on carboxymethy chitosan (CMC) molecules. The reaction factors such as molecular weight, mole ratio of anhydride to amino, temperature and solvent were examined. Nanoparticles were obtained by blending botanical insecticide capsaicin (Cap) and CMC-g-RA. Surface shape, particle size, polydispersity index, surface charge, LE and stability of Cap/CMC-g-RA nanoparticles were characterized. The results showed that lower molecular weight was of advantage to higher degree of RA substitution. CMC-g-RA and Cap formed drug delivery nanoparticles with spherical shape and negative surface charge in water. The increased concentration of drug or carrier resulted in higher zeta potential and narrower polydispersity index (PDI) of Cap/CMC-g-RA. The loading efficiency (LE) of nanoparticles was up to 0.86, which provided efficiently protection for Cap, extended drug releasing period and dosage.

A New Family of Anionic Surfactants for Enhanced-Oil-Recovery Applications

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 829-840 ◽  
Author(s):  
Bo Gao ◽  
Mukul M. Sharma
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Gemini Surfactants ◽  
Anionic Surfactants ◽  
Interfacial Properties ◽  
Single Chain ◽  
New Family ◽  
Low Concentrations ◽  
Reservoir Conditions ◽  
Hydrophobic Tail

Summary A new family of anionic surfactants that has great potential for enhanced-oil-recovery (EOR) applications was synthesized and characterized in our laboratory. The unique and versatile structure of these surfactants has endowed them with properties that are attractive for EOR. A detailed experimental study was carried out and is presented here on the oil/water and solid/water interfacial properties of seven novel molecules. The interfacial properties of this series of seven anionic surfactants with different lengths of hydrophobic tail and linking spacer group show systematic trends in interfacial tension (IFT) and static adsorption density with changes in solution conditions. These molecules showed excellent aqueous stability even in high-salinity and hard brines. Ultralow IFT (ULIFT) values were measured at low surfactant concentrations. The synthesized Gemini surfactants also showed lower maximal adsorption densities than the conventional single-chain surfactants. The results from this study showed the potential of using these surfactants at low concentrations and in harsh reservoir conditions.

Electrophoretic mobility of microsomes from rat liver

1977 ◽  
Vol 23 (1) ◽  
pp. 285-297
Author(s):  
D. Blad ◽  
L. Winqvist ◽  
G. Dallner
Keyword(s):  
Electrophoretic Mobility ◽  
Liver Microsomes ◽  
Protein Species ◽  
Electrophoretic Mobilities ◽  
Low Concentrations ◽  
Structural Differences ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
And Control ◽  
Phosphate Groups

The electrophoretic mobilities of rough and smooth microsomes were studied using free electrophoresis in a sucrose gradient. Rough microsomes have a higher net negative surface charge but removal of the ribosomes decreases their mobility to that of smooth microsomes. Treatment with neuraminidase and phospholipases C and D does not affect the mobility of total smooth microsomes, but this mobility is increased by approximately 20% after trypsin and papain treatment and by approximately 12% after phospholipase A treatment. Further treatment of trypsin-digested smooth microsomes with phospholipase C re-establishes the original mobility. This effect is not caused by the removal of lipid phosphate groups, but by the liberation of negatively charged protein species that are normally buried under trypsin-sensitive proteins. Low concentrations of trypsin also solubilize enzyme proteins from smooth liver microsomes of phenobarbital-treated rats, but the electrophoretic mobility is not increased, indicating structural differences between induced and control membranes.

Sign in / Sign up

Export Citation Format

Share Document