Influence of Salt Concentration and Type on Dielectric Permittivity of Rocks

Summary Ionic properties and concentration significantly influence the response of brine-saturated rocks to electromagnetic disturbance. However, the dielectric permittivity response of rocks under different ionic conditions is poorly described. This significantly limits the potential information that could be gained from dielectric permittivity measurements about the pore geometry and fluid content. The influence of salt concentration and type on broadband dielectric permittivity must be reliably quantified to enhance interpretation of dielectric permittivity measurements. The main objective of this paper is to quantify the influence of salt type and concentration on dielectric permittivity via experimental measurements and pore-scale simulations. We examine the impact of salt concentration and type on the dielectric permittivity of pore- and core-scale Berea sandstone (BS) samples. First, we perform frequency-domain dielectric permittivity simulations to quantify the response of the pore-scale models to electric field excitation. The frequency-domain dielectric permittivity simulator solves Maxwell’s equations under quasistatic conditions at discrete frequencies. We simulate the dielectric permittivity in the frequency range of 20 MHz to 3 GHz. We perform the simulations in samples saturated with NaCl, KCl, and MgCl2 brines. The salt concentration of the brine solutions ranges between 10 PPT and 100 PPT (parts per thousand). We fully saturate the samples with different brine solutions at varying salt concentrations for the core-scale analysis. In the core-scale domain, we use the brine solutions and salt concentrations assumed in the pore-scale analysis. The dielectric permittivity measurements were conducted using a network analyzer with a high-temperature coaxial probe setup in the frequency range of 300 MHz to 3 GHz. We observed that relative permittivity at 1 GHz increases with increasing salt concentration, irrespective of the brine type. However, the type of salt significantly controls the magnitude of the decrease in relative permittivity. After increasing the salt concentration from 10 PPT to 100 PPT, relative permittivity at 1 GHz increased by 11% and 7% when the samples were saturated with KCl and NaCl brine solutions, respectively; at 20 MHz, the same increase in salt concentration caused rock relative permittivity to increase by only 1% and 5% in the samples saturated with KCl and NaCl brines, respectively. The lower sensitivity of relative permittivity to salt concentration at 20 MHz compared to 1 GHz can be attributed to the combined influence of interfacial and orientational polarizations on rock dielectric permittivity. The impact of salt type on relative permittivity was negligible in samples saturated with 10 PPT brine solutions. Results demonstrated that taking the influence of salt concentration and type into account is critical for reliable interpretation of dielectric permittivity measurements. The novel contribution of this work is the documentation of how the saturating brine type influences the complex dielectric permittivity of the rocks. This work illuminates the extent to which the relative permittivity can be used for petrophysical analysis in cases where the formation brine salt concentration is uncertain. Additionally, the outcomes of this work will contribute to enhanced interpretation of dielectric permittivity measurements in formations with variable salt concentrations of formation water.

Influence of salt concentration on the salting kinetics of cod loin ( Gadus morhua) during brine salting

SummarySalt concentrations of brine above 10% are still commonly used in fish marinating process. The study has showed an increasing salt concentrations affect to adversely all the properties of marinated herring meat. Increase in salt concentration from 5% to 15% resulted in significantly (P < 0.05) decrease content of water, non‐protein nitrogen and products of protein hydrolysis. Consequently, weight yield of marinated fresh herring decreased from 83% to 74%. The most palatable marinades contained 2–3% NaCl in meat only. The higher salt concentrations applied significantly (P < 0.05) worsened the taste, texture and colour of marinated herring. Texture profile analyses (TPA), free hydroxyproline content and colour analyses (L*a*b) confirmed the negative influence of high salt concentration on the marinades quality. Frozen and thawed herring tissue showed greater sensitivity to salt. Namely, marinades from frozen fish contained by 0.3 more salt (P < 0.05), and the weight yield was by 2.3–10.3 percent point lower than from the fresh herring. Meat from frozen herring when matured has significantly (P < 0.05) lower sensory value, lower content of protein hydrolysis products, free hydroxyproline and higher parameter b* value of than the fresh one.

Little is known about how aqueous electrolyte exposure affects hydrated polymer relative permittivity and state of water properties. Increasing NaCl solution concentration (0.01, 0.1, and 1.0 mol/L) caused a cross-linked glycidyl and glycerol methacrylate-based copolymer to osmotically deswell and caused ion sorption to increase opposite to electrostatic theory and Maxwell Garnett equation predictions. The presence, due to salt solution equilibration, of ions in the polymer drove an increase in static permittivity compared to that of pure water-equilibrated equivalent water content samples. The influence of salt concentration on hydrated polymer dielectric permittivity properties was fundamentally different from its influence on aqueous electrolyte solutions where dielectric permittivity decreases as salt concentration increases. Generally, the amount of bulk-like water in the polymers decreased as salt concentration increased, but a maximum was observed in low water content (<7% by mass) polymers, suggesting that ions and water may compete for interactions with the polymer.

Fluid saturations and distributions, water salinity, pore structure, and porosity affect dielectric permittivity measurements. However, the conventional dielectric permittivity mixture models, such as Complex Refractive Index Model (CRIM) and Hanai-Bruggeman (HB) do not quantitatively include the cumulative effect of the aforementioned petrophysical properties. Moreover, the effect of salt concentration on multi-frequency dielectric permittivity measurements still needs to be investigated. The objectives of this paper are (a) to investigate the effect of salt concentration on complex multi-frequency dielectric permittivity responses in rocks with complex pore structure, (b) to develop a new workflow for estimating multi-frequency dielectric permittivity of rock samples taking into account the complexity of pore structure, different polarization mechanisms, porosity, water saturation, and salt concentration, and (c) to develop an inversion algorithm to simultaneously estimate water saturation and salinity from dielectric dispersion data. First, we conduct dielectric permittivity experiments on fully brine-saturated rock samples. Then, we change the salinity of the samples and perform dielectric permittivity experiments on the rock samples at different water salinity levels. Next, we develop a new rock-physics workflow which includes the combined effect of the aforementioned petrophysical properties. The new workflow calculates the multi-frequency complex dielectric permittivity responses of synthetic rock samples. Then, we use an automated inversion algorithm to simultaneously estimate water saturation and salinity of actual rock samples from the joint interpretation of the real and imaginary parts of multi-frequency dielectric permittivity measurements. We successfully verified the reliability of the new workflow in the core-scale domain using 12 different rock samples in the Barra Velha formation. The new workflow simultaneously estimated water saturation and salinity with average relative errors less than 12% and 14%, respectively. Moreover, we observed that the average relative errors between the experimentally observed and calculated dielectric permittivity that are obtained from the introduced mixture model, CRIM, and HB are 11%, 121%, and 26%, respectively. We demonstrated that the effect of salt concentration could have significant effects on dielectric permittivity responses up to 3 GHz and has to be reliably taken into account in interpretation of dielectric measurements. The multi-frequency joint interpretation of the real and imaginary parts of dielectric permittivity measurements makes the introduced workflow a robust interpretation technique in the presence of uncertainties in the estimates of the formation water salinity. Moreover, unlike the conventional dielectric mixture models, the introduced workflow honors the complexity of pore structure and composition, water salinity, and different polarization mechanisms.

Dielectric permittivity measurements are used across various geoscience-related applications for the purpose of determining soil moisture content, characterizing soil and rock properties, and monitoring geoprocesses. However, their accuracy is often compromised by the diverse composition of natural brines. A key aspect of interpreting dielectric permittivity measurements is having a reliable model for the saturating brine solution. It is unclear whether the existing models, typically based on single-salt NaCl solutions, fail to account for diverse ionic mixtures. We address this gap by developing a comprehensive dielectric model from an extensive experimental dataset of eight salts (i.e., NaCl, KCl, CaCl 2 , MgCl 2 , K 2 CO 3 , K 2 SO 4 , LiCl, NaBr). This dataset includes more than 200 measurements of both single salt solutions and complex mixtures. The results demonstrate that for brines dominated by Na + , Ca 2+ , and Cl - ions, a simple NaCl-based model can be used in practical applications in the absence of extended ionic analysis when the salt concentration is below 100 kilo parts per million (kppm). However, at salt concentrations above this threshold, the permittivity of the aqueous salt solution needs to be determined by considering the specific concentration of each constituent ion. For diverse multi-component brines, we propose a linear mixing rule that predicts static permittivity with a mean absolute percentage error of 0.7%. This work provides an experimentally grounded framework for bulk brine permittivity under controlled laboratory conditions (20.2 ± 0.1 °C, atmospheric pressure), serving as a foundational baseline for calibration standards used in hydrology, geosciences, and petroleum engineering applications.

This study was conducted to evaluate the growth of lactic acid bacteria and quality characteristics of Baechu kimchi prepared with four types of salt (Solar salt, Flower salt, Hanju salt, and Roasted salt) at two different concentrations (10, 15%) during storage. The quality characteristics of kimchi were examined by investigating acid production, growth of lactic acid bacteria, sensory properties, salinity, texture, and color characteristics. Baechu kimchi was fermented for 18 days at <TEX>$10^{\circ}C$</TEX>. The pH and total acidity did not change during storage according to type and concentration of salt. Growth of lactic acid bacteria was not affected by type of salt, whereas it was inhibited at 15% salt concentration after 9 days of fermentation. In the quantitative descriptive analysis of sensory properties, kimchi prepared with 10% salt showed significantly higher scores in term of overall acceptability (p<0.05). Meanwhile, there was no significant difference by type of salt. For texture characteristics, hardness of kimchi prepared with 10% salt was significantly higher than that with 20% salt. For color characteristics, L value (brightness) and b values (yellowness) of kimchi prepared with 10% salt increased during fermentation, whereas a value (redness) did not change by type and concentration of salt. The results of this study show that there were no considerable differences in quality characteristics of Baechu kimchi prepared with various types and concentrations of salt. However, Solar salt resulted in more favorable sensory properties and salinity of kimchi than any other types. Further, kimchi prepared with 10% salt showed significantly higher scores in terms of overall acceptability, growth of lactic acid bacteria, salinity, texture, and color characteristics.

Influence of salt concentration and pH value on the degradation of epoxy resin used in FRP bars under simulated marine conditions

Core Ideas Salinity adversely affected Kentucky bluegrass growth and performance. Chloride salts were more detrimental to Kentucky bluegrass than sulfate salts when applied at the same electrical conductivity. Kenblue had a higher growth rate than Moonlight’under the saline condition at the seedling stage; however, Moonlight outperformed Kenblue at the vegetative growth stage. The growth and functionality of turfgrasses are often challenged by high soil salinity. Previous research mainly focused on plant responses to Cl− salt–induced saline conditions (e.g., NaCl). However, in some regions, including California and North Dakota, in salt‐affected soils the predominant cation is Mg2+ and the predominant anion is SO42−. The responses of turfgrass species to such salinity conditions have not been well documented. In this research, the responses of Kentucky bluegrass (Poa pratensis L.) cultivars Kenblue and Moonlight at the seedling growth and the vegetative growth stages to different salt type (NaCl, Na2SO4, MgCl2, and MgSO4) and concentration (5–20 dS m−1) were investigated. Results showed that shoot dry weight (SDW), root dry weight (RDW), root length (RL), and visual quality of the two turf cultivars decreased with increasing salt concentration at both growth stages. Specific root length increased to 235.7% of the control at the seedling growth stage but decreased to 71.6% of the control at the same salt concentration at the vegetative growth stage. Under the saline condition, Kenblue showed higher SDW (52.1%), RDW (74.4%), and RL (20.6%) than Moonlight at the seedling growth stage; however, Moonlight performed better than Kenblue at the vegetative growth stage. The two turf cultivars were more tolerant to Na2SO4 and MgSO4 stress than to NaCl and MgCl2 stress. Our research indicates that turfgrass managers need to consider plant material (cultivar and growth stage), salt type, and salt concentration to develop a successful salinity management plan.

An important acidic protease, pepsin is synthesized and secreted in the gastric membrane in an inactive state called pepsinogen (PG) and has applications in the food and manufacturing industries, collagen extraction, gelatin extraction and in regulating digestibility. Fish processing waste can be used to produce commercially valuable byproducts such as pepsinogen. In the present study, the purification of pepsinogen from the stomach of red perch using aqueous two phase systems (ATPS) formed by polyethylene glycol (PEG) and salt at 4°C was optimized. The effects of salt type (MgSO4, (NH4)2SO4, Na3C6H5O7 and K2HPO4) and concentration (6, 7, 8, 9, 10, 11, 12, 13, 15, 17, 19%) on the partitioning of PG were studied and parameters including total volume (TV), volume ratio (VR), enzyme activity (AE), protein content (Cp), specific activity (SA), partition coefficient (Kp), purification fold (PF) and recovery yield (RY) were evaluated. Salt type and salt concentration had significant effects on each parameter. MgSO4, (NH4)2SO4, Na3C6H5O7 and K2HPO4 required different critical salt concentrations (9, 12, 12 and 10%, respectively) to form biphasic systems. TV and VR decreased with increased salt concentration since salt formed hydrogen bonds with water molecules and created a more compact and ordered water structure. AE, CP, SA, PF and RY showed a maximum increase with intermediate salt concentration, while KP had the opposite pattern. The highest TV and AE values were obtained at 12% (NH4)2SO4 while the highest SA and PF values were obtained at 12% MgSO4. The highest TV and Cp values were obtained at 12 and 15% Na3C6H5O7, respectively. (NH4)2SO4 at 15% concentration gave the highest RY (71.7%) and was selected as the optimum salt type and concentration. Thus, 15% (NH4)2SO4 18% PEG 1500 was the optimal ATPS combination and presented the best partition. The values of SA and PF and RY obtained with ATPS method were two fold higher than those obtained with the ammonium sulphate fractionation (ASF) method.

Water resource quality (WRQ) is affected by salt concentration and topographical position. Indeed, an increase in salt concentration, which decreases water availability for animal and plant nutrition, and lower altitude, which diminishes the potential for production of hydropower, negatively affects WRQ. Therefore, it is useful to develop indicators like osmotic power (OP) and hydraulic power (HP) to evaluate, respectively, the influence of salt concentration and topographical position on WRQ. The main objective of this work was to evaluate the WRQ in 11 hydrographical basins in peninsular Spain. In this paper, OP, HP and the total power (TP), obtained by adding OP to HP, were calculated at three different basin levels: • Height H25 (m) corresponding to 25% of total surface area of the basin • Height H50 (m) corresponding to 50% • Height H100 (m) corresponding to 100%. Results showed that OP, HP and TP values of water basins decreased from the northern to the southern parts of peninsular Spain, according to water scarcity and hydrographical characteristics of water basins. The higher OP, HP and TP values, the higher is WRQ of the basin. Therefore, TP, OP and HP can be used to evaluate WRQ at the administrative water basin level as a basis for water resource management. Indeed, these indicators can assist water managers and planners in deciding between inter-basin water transfers and water desalination, especially in countries where water is a scarce resource. Water SA Vol.31 (2) 2005: pp.199-208

The influence of salt concentration on the size and on the thermodynamic stability of interpolymer complexes composed of oppositely charged macroions having different affinity to solvent was studied from a theoretical viewpoint. It was shown that increasing salt concentration causes changes in the structure of complex particles. At low salt concentration, the particles preserve their structure and size. At a critical salt concentration, nScr, the particle size rises sharply to a slightly larger dimension. From this concentration, the macroions forming the interpolymer complex start to separate, and the complex is fully destroyed at a salt concentration nS*. After separation, the macroions coexist in solution and with further increase in salt concentration reduce their sizes according to the screening of polyion charges by salt ions. nScr and nS* depend on physical parameters such as the degree of polymerization of macroions, their degree of ionization, and macroion−solvent interaction parameters. Experime...

Linkage of pH, Anion and Cation Effects in Protein-Nucleic Acid Equilibria: Escherichia coli SSB Protein-Single Stranded Nucleic Acid Interactions

Iranian White cheese was manufactured from ultrafiltered cows' milk using different concentrations of salt consisting of 1, 2.5, 4% and salt free. Chemical composition, proteolysis, counts for lactic acid bacteria and sensory evaluation were examined during 90 d of ripening. It was found that the use of different salt concentrations significantly influenced all chemical composition, proteolysis, total number of lactic acid bacteria and sensory characteristics of the cheeses. Increasing the salt concentrations caused a proportional decrease in proteolysis determined by both urea-PAGE of caseins and RP-HPLC of peptides. With increased salt concentration, total number of lactic acid bacteria decreased. Cheeses with 1 and 2.5% salt were suitable and acceptable in odour and flavour that may be due to the proportional level of proteolysis products. In conclusion, reducing salt concentration from 4 to 2.5 and 1% had no ineligible effect on the quality and acceptability of the cheese.

The detection of methicillin resistance by the breakpoint method was examined using three different media containing varying quantities of added salt and 4 mg/L methicillin or 1 mg/L oxacillin. Three hundred clinical isolates of eight species of coagulase-negative staphylococci were tested. In 68 strains methicillin resistance was expressed only at certain salt concentrations and four distinct susceptibility phenotypes were observed. A correlation between the susceptibility phenotype and the species of the isolate was found. Testing on Columbia agar (CA) containing 4 mg/L methicillin with 0% and 4% added salt was required to detect resistance in all 68 strains. Resistance was detected less frequently using Balanced Sensitivity Test (BST) agar or Diagnostic Sensitivity Test (DST) agar containing methicillin or CA, BST or DST agar containing oxacillin. Increased production of beta-lactamase was shown to be an unlikely cause of MR in these strains. Disc sensitivity tests were performed on the 68 strains using five different media. Columbia agar gave optimum results as the other media gave enhanced zones of inhibition for some isolates. Further tests were performed on CA containing varying salt concentrations using both oxacillin and methicillin discs. A close relationship between the staphylococcal species, and the influence of increasing salt concentration on zone size was found. Discrepancies were noted between results obtained by breakpoint and the results obtained with methicillin discs particularly with Staphylococcus simulans and some Staphylococcus epidermidis strains. Results obtained with oxacillin discs more closely correlated with those obtained by breakpoint, but only when disc tests were performed on media with low and high salt content. To identify methicillin resistance in strains of CNS by disc tests, the use of Columbia agar with 0% and 5% added salt and oxacillin discs is recommended.