Influence Of Ionic Composition Research Articles

Influence of ionic composition in aqueous solution on wettability of rock surface-experiment and economics evaluation

In this study, the influence of different ionic composition in aqueous solution on the minerals surface wettability was studied. The differences effect of monovalent ion and divalent ions onto the wettability alteration were studied. The anions were Cl- and SO42-. The SO42- could make the minerals surface more hydrophilic. Besides, the influence of NaCl, MgCl2, CaCl2, Na2SO4, K2SO4 and MgSO4 on the mineral wettability alteration were studied. The results indicated that divalent ions showed significant impact on the minerals wettability alteration, compared with monovalent ion. The reasons were due to the fact that divalent ions showed higher ions adsorption than monovalent ion, and divalent ions have higher effect on compressing the electric double layer. The static contact angle and dynamic contact angle were measured. Different heavy oils were studied, including heavy oil with 100 ppm, heavy oil, heavy oil without resins, heavy oil without asphaltenes. The results showed that the asphaltenes would make it difficult for the heavy oils to liberate from minerals, thus decreasing the oil drops contact angle. Then the resins would decrease the heavy oil contact angles. CaCl2/MgCl2 and K2SO4 have synergistic effect on the change of the minerals surface wettability. Atomic force microscope (AFM) measurement indicated that the ions would effectively decrease the interaction force on the surface of heavy oil-minerals, which was beneficial to the heavy oil liberation. The roughness measurement indicated that the different ions would effectively increase the minerals surface wettability.

Influence of ionic composition on minerals and source rocks: An investigation between carbonate-type and sulfate-type lacustrine sediments based on hydrochemical classification

The geochemical characteristics and distribution of saline lacustrine source rocks are shaped up by the environment and conditions under which they develop. Such environments, in turn, are often heavily influenced by various salt minerals and clay minerals. Therefore, the current study aims to investigate the potential impact of common salt minerals and clays on the formation and chemical changes of source rocks in salt lakes. Instead of relying on conventional classification methods that emphasize salinity, this study divides common petroleum-bearing saline lacustrine sedimentary basins into two types, the carbonate-type and the sulfate-type, based on the hydrochemistry of salt lakes. Experimental comparison of inorganic geochemistry between samples from modern and ancient saline lacustrine sedimentary systems revealed key differences in ion composition, and resultantly in the sedimentary sequences of salt minerals, the transformation of clay minerals, and the evolution of source rocks. It is found that CaCO3-bearing minerals are the first to precipitate in both types of salt lakes. However, secondary mineral deposition in carbonate-type saline lacustrine systems features the precipitation of Na2CO3-bearing alkaline minerals due to the depletion of Ca2+. Meanwhile, the clay in carbonate-type salt lakes contains a relatively high level of smectite and mixed-layer illite/smectite, as well as low content of illite, implying an impediment in smectite illitization. In contrast, sulfate-type salt lakes are enriched in Ca2+ but depleted in CO32−, leading to the abundant development of Ca-bearing sulfate mineral deposits such as gypsum. These geochemical differences could be responsible for the propensity of carbonate-type salt lakes to harbor well-developed oil shale, and for the tendency of source rocks deposited in sulfate-type lacustrine systems to produce oils at the immature stage.

Two Subtypes of Nicotinic Acetylcholine Receptors in Lymnaea stagnalis Neurons Control Chloride Conductance

Giant neurons of the mollusc Lymnaea stagnalis contain heterogeneous population of nicotinic acetylcholine receptors (nAChRs) according to their relative sensitivity to antagonists. All these receptors are involved in the total response to acetylcholine (ACh). To evaluate activity of different pharmacological agents correctly it is necessary to know ionic selectivity of nAChRs which participate in transmembrane ionic current. In this work we studied the influence of ionic composition of the external and intracellular solutions on the current amplitude and current–voltage relation under the action of ACh or other nAChR agonists on the identified neurons of the left and right parietal ganglia of Lymnaea. After non-permeable cation N-methyl-D-glucamine was completely substituted for external Na+ ions there were no changes in the current characteristics. After a 10-fold decrease in Cl–concentration in the external solution there was a considerable shift of the current–voltage curve to the right, outward currents at the holding potential (Vh) up to 30 mV were not observed. On the contrary, a 10-fold decrease of Cl– concentration in the intracellular solution led to a shift of the current–voltage curve to hyperpolarizing direction, the reversal potential shift was in the average –42 mV. When ACh and nicotinic agonists with higher selectivity towards vertebrate α7 neuronal nAChR type and one of the two subtypes of Lymnaea nAChRs were compared, no differences in changes of ionic current characteristics were found. Neurons with distinct relative fraction of one or another nAChR subtype reacted to Cl– concentration change in the same way. Our results support earlier data on Cl– mechanism of Lymnaea neuron responses to ACh and evidence identical ionic selectivity of the two nAChR subtypes in identified neurons tested.

Interaction of ions in water affects water quality of freshwater lake: a case study of major lakes of North India

The influence of ionic composition on the water chemistry and thereby on aquatic flora was investigated. Two major wetlands of North India were taken for the study. Quality parameters of the lakes showed the enrichment of the water especially in the month of September with higher values of P and BOD in almost all of the lakes viz., LSJ, LCH, LSN, and LHT as <5.0, 9.0, 1.0, 1.7 and <7.3, 6.0, 6.3, and 4.0, respectively. Statistically correlated values of the ions in the water quality showed an effect of one on another. An attempt has also been made to investigate if ionic constituent is one of the major causes affecting the aquatic floral diversity.

Characterization of the redox components of transplasma membrane electron transport system from Leishmania donovani promastigotes

An investigation has been made of the points of coupling of four nonpermeable electron acceptors e.g., alpha-lipoic acid (ALA), 5,5'-dithiobis (2-nitroaniline-N-sulphonic acid) (DTNS), 1,2-naphthoquinone-4-sulphonic acid (NQSA) and ferricyanide which are mainly reduced via an interaction with the redox sites present in the plasma membrane of Leishmania donovani promastigotes. ALA, DTNS, NQSA and ferricyanide reduction and part of O2 reduction is shown to take place on the exoplasmic face of the cell, for it is affected by external pH and agents that react with the external surface. Redox enzymes of the transplasma membrane electron transport system orderly transfer electron from one redox carrier to the next with the molecular oxygen as the final electron acceptor. The redox carriers mediate the transfer of electrons from metabolically generated reductant to nonpermeable electron acceptors and oxygen. At a pH of 6.4, respiration of Leishmania cells on glucose substrate shut down almost completely upon addition of an uncoupler FCCP and K+-ionophore valinomycin. The most pronounced effects on O2 uptake were obtained by treatment with antimycin A, 2-heptadecyl-4-hydroxyquinone-N-oxide, paracholoromercuribenzene sulphonic acid and trifluoperazine. Relatively smaller effects were obtained by treatment with potassium cyanide. Inhibition observed with respect to the reduction of the electron acceptors ALA, DTNS, NQSA and ferricyanide was not similar in most cases. The redox chain appears to be branched at several points and it is suggested that this redox chain incorporate iron-sulphur center, b-cytochromes, cyanide insensitive oxygen redox site, Na+ and K+ channel, capsaicin inhibited energy coupling site and trifluoperazine inhibited energy linked P-type ATPase. We analyzed the influence of ionic composition of the medium on reduction of electron acceptors in Leishmania donovani promastigotes. Our data suggest that K+ have some role for ALA reduction and Na+ for ferricyanide reduction. No significant effects were found with DTNS and NQSA reduction when Na+ or K+ was omitted from the medium. Stimulation of ALA, DTNS, NQSA and ferricyanide reduction was obtained by omitting Cl- from the medium. We propose that this redox system may be an energy source for control of membrane function in Leishmania cells.

Influence of ionic composition on NOM size and removal by ultrafiltration

In this study, the effects of Na+ and Ca2+ on the apparent MWt distribution and removal efficiency of NOM by deadend ultrafiltration were investigated. NOM samples from Singapore (reservoir-based), IHSS (river-based standard) and Biohumic (soil-based) were used. The effective particle sizes and MWt distributions of the NOM, with and without ions, were analyzed by light scattering and HPSEC, respectively. The effective size of the NOM was significantly reduced by increasing the Na+ concentration. This was robably due to coil-to-globule conversion and polyelectrolyte interaction, changing the NOM conformation from linear to spherical. However, increasing the concentration of Ca2+ showed competing effects. At relatively low concentrations of Ca2+, the size of the NOM was reduced, presumably by the mechanism attributed to Na+. As the concentration of Ca2+ was further increased the NOM size increased, due to aggregation or chelation between humic acid in the NOM and Ca2+ becoming the dominant factor. Ion interactions with NOM also had a significant impact on removal by ultrafiltration. With addition of Na+, the Singapore NOM retention decreased from 52% to 29%. In contrast, the retention of Biohumic NOM increased from 45% to around 70% with an increase in Ca2+ concentration.

Influence of Ionic Composition on Nitrate Retention by Nanofiltration

This study was developed to highlight the influence of the nature of the water to be treated on the efficiency of nitrate elimination by a commercial membrane. By modifying the pH and gradually increasing the complexity of the treated solutions (binary, ternary and then natural waters), we identified phenomena which govern the ion transfer across the membrane. We underline the influence on membrane selectivity of the hydration energy as well as the membrane–solute and the solute–solute interactions. The observations made with simple nitrated solutions (binary and ternary) were extrapolated and confirmed in experiments made on polluted or nitrates-doped waters.

Influence of ionic composition on acid-base regulation in rainbow trout (Oncorhynchus mykiss) exposed to environmental hypercapnia

The influence of ambient calcium, bicarbonate and chloride levels on acid-base regulation was investigated in rainbow trout acclimated and exposed to hypercapnia in five different water types. In soft water (low [Ca++] and [HCO3−]), compensation of the respiratory acidosis was slow and incomplete within 72h. High ambient [HCO3−] clearly improved extracellular HCO3− accumulation, and pH recovery was accomplished within 24h. This may result from stimulation of branchial HCO3− (influx)/Cl− (outflux) exchange. Elevation of ambient [Cl−] had a small, positive effect on pH compensation. High ambient [Ca++] improved the degree of pH compensation. Plasma [HCO3−] and [Cl−] showed an inverse 1:1 relationship in all acclimation groups, revealing an ubiquitous chloride-mediated acid-base regulation. Ventilation activity was increased by hypercapnia and only returned to control values in hard water (high [HCO3−]and [Ca++]). During progressive hypercapnia (up to 3% CO2), hard water acclimated fish obtained significantly higher plasma [HC03−] (51.2 mM) than fish acclimated to low [Ca++]/high [HCO3−] (44.7 mM). This suggests an additive effect of ambient Ca++ on plasma HCO3− accumulation. At levels of CO2 above 1%, some mortality was induced in low [Ca++]/high [HCO3−] water. Dying fish could be distinguished from surviving fish by an excessive Cl−loss and increasing extracellular anion gap.

The influence of ionic composition on the distribution of nematode species in springs of the province of Granada (Spain)

The ionic composition of 38 mineral springs in the province of Granada (Spain), and the distribution of 45 species of nematodes belonging to orders Monhysterida, Araeolaimida, Chromadorida and Enoplida were examined. Water chemistry is used to make two diagrams representing anionic and cationic composition. Diagrams for anionic composition (given the greater variance seen in the springs considered) are used to illustrate the distribution of individual species. The results obtained from species distribution and the correlation between species made it possible to group species which could be associated with springs where each of the anions considered predominated. A greater number of species groups was found to inhabit springs in which chloride concentrations was less than 50% of the total concentration of anions.

ChemInform Abstract: Influence of Ionic Composition on the Electrodissolution and Passivation of Iron Electrodes in Potassium Carbonate‐Bicarbonate Solutions in the 8.4‐10.5 pH Range at 25 °C.

AbstractFrom the experimental results, obtained by voltammetric and rotating disc electrode techniques, it is concluded that in the CO32‐/HCO3‐ buffer the kinetic response of iron in the potential range of the prepassive stage is principally determined by the HCO3‐ concentration.

The influence of ionic composition on the electrodissolution and passivation of iron electrodes in potassium carbonate-bicarbonate solutions in the 8.4–10.5 pH range at 25°C

The influence of ionic composition on the electrodissolution and passivation of iron electrodes in potassium carbonate/bicarbonate buffers is studied over the concentration range of anions compatible with the regulating capacity of the buffer, at 25°C, by using voltammetric and rotating disc electrode techniques. Data are discussed on the basis that the interaction between Fe 2+ and HCO 3 − ions plays an important role at the outer part of the passivating layer where the local pH resulting from the thickening of the passivating layer is determined by the coupling of different ionic equilibria.

The slow repolarization phase of the action potential in rat heart.

Intracellular action potentials and isometric force were measured from thin trabeculae of the right ventricle of rat heart. Characteristic for the action potential of rat myocardium is a short plateau and a slow final repolarization phase. We have studied the influence of ionic composition of the medium and of stimulation frequency on the slow phase of repolarization and its relation to peak force. The results confirmed a positive correlation between peak force and the duration of the slow phase of repolarization, as has been reported for other species. An increase of [Ca2+]o caused a shortening of the slow phase of repolarization when peak force was kept constant. In low [Na+]o peak force was increased and the slow phase of repolarization was shortened. Reperfusion with normal medium after a period in low [Na+]o induced a transient prolongation of the slow phase of repolarization and reduction of peak force. The transient lasted about 20 min. In the presence of the Ca2+ entry blocker nifedipine the action potential duration and peak force were reduced. Low [Na+]o caused less shortening of the slow phase of repolarization and a greater increase of peak force. The slow phase of repolarization was prolonged transiently following reperfusion at normal [Na+]o, but only during a few beats. These results are in agreement with the hypothesis that the slow phase of repolarization is due to an inward current generated by Na+-Ca2+ exchange, as latter mechanism is known to be sensitive to the intracellular and extracellular concentrations of both Na+ and Ca2+.

Influence of ionic composition, buffering agent, and pH on the histochemical demonstration of myofibrillar actomyosin ATPase

The influence of the composition of the preincubation medium on the histochemical demonstration of myofibrillar actomyosin ATPase, including a variety of carboxylic acid and non-carboxylic acid buffering compounds and neutral salts, was studied. In inorganic salt-free systems the rate of the activation of type I fibers and inactivation of type II fibers was accelerated when the carboxylic acids had longer chain length or multiple carboxyl groups. Of these factors, the number of carboxyl groups was dominant with a 100 mM citrate buffer producing a sharp differentiation between fiber types. In contrast, the time course of the response was exceptionally long in an acetate buffer. The time course of the ATPase reaction was also modified by other buffers at pH 4.60. The most notable were an ascorbate - glycine buffer system which produced little or no deviation from the alkaline preincubation staining pattern after prolonged preincubation and a pyrophosphate system which produced a rapid change. Neutral salts in the preincubation medium accelerated the time course of the inactivation - activation process with the order for the halogen salts of K+ being F- less than Cl- less than Br- less than I-, which is a progression by molecular weight. The only sequence for cations on the myofibrillar actomyosin ATPase was Li+ less than Na+ less than K+. The response to salts was concentration dependent. An interaction existed between buffering compound, type of salt, and pH. These experiments demonstrate that the histochemical differentiation of fiber types by the myofibrillar actomyosin ATPase reaction depends upon a modification of some component(s) of the myofibrillar complex that can be influenced by a number of factors.

Influence of ionic composition, buffering agent, and pH on the histochemical demonstration of myofibrillar actomyosin ATPase

Influence of ionic composition, buffering agent, and pH on the histochemical demonstration of myofibrillar actomyosin ATPase

Extractant Influence on the Relationship between Extractable Proteins and Cold Tolerance of Alfalfa

The influence of ionic composition and pH of extractant on the relationship between the extracted proteins and the cold tolerance of Vernal and Arizona Common alfalfa (Medicago sativa L.) was examined. Five environments were used to induce different tolerance levels. The quantity of protein extracted from plants was influenced by the hardening environment, cultivar, and ionic composition and pH of 29 extractants. Extractants with a pH below 6 generally extracted less protein.The measured cold tolerance of the plants was correlated with the quantity of protein detected in many of the 14 regions of the electrophoresis gel columns regardless of extractant but was most closely associated with the protein in either region 7 or 8 with nine of ten extractants.The magnitudes of cultivar and hardening effects on quantities of protein detected on various column regions were influenced by choice of extractant. This suggests that proper extractant selection may be vital for study of isozymes by electrophoresis.