Water Salt Solutions Research Articles

Solution Uptake in Cylindrical Carbon-Fibre-Reinforced Polymer (CFRP) Tendons

Salt water exposure conditions relevant to carbon-fibre-reinforced polymer (CFRP) prestressed concrete structures in marine environments are investigated. The diffusion into relatively small diameter CFRP tendons can be a lengthy process so the prediction of the long-term moisture uptake using short-term experiments on thin films of epoxy would be advantageous. However, the fibre inclusions within a composite introduce complexities, and factors are typically required for correlation with pure epoxy specimens. Diffusion parameters based on moisture uptake result from CFRP tendons exposed to salt water solution at 20°C and 60°C are compared with those obtained using equivalent thin film specimens. The higher temperature is selected to accelerate the moisture uptake. It is found that the measured ratios of tendon and epoxy diffusivity were temperature dependent, and the combination of the higher temperature and salt solution leads to an increased propensity for moisture uptake in the tendon. Existing analytical models to predict the CFRP tendon diffusivity from that of a thin film of epoxy did not appear to capture the observed trends. However, predictions using a unit cell with a fibre interface zone suggest that this may be due to an increased diffusivity in the interphase region.

Interfacial characteristics of BIOfactor MTA and Biodentine with dentin.

The objective of this study was to characterize the interface between dentin and MTA-Angelus (Angelus, Londrina, Brasil), Biodentine (Septodont, France) and BIOfactor MTA (Imicryl, Konya, Turkey) using scanning electron microscopy (SEM), energy disperse X-ray spectroscopy (SEM-EDS) and confocal laser scanning microscopy (CLSM). Fifteen dentin segments were obtained from previously extracted single-rooted human teeth. Canal lumens were instrumented with diamond burs and then randomly filled with MTA-Angelus, Biodentine or BIOfactor MTA and placed in distilled water or Hanks' Balanced Salt Solution (HBSS) for 28-days. The samples were examined with SEM and the thickness of the interfacial layer measured. SEM-EDS analysis was performed to determine principal elemental composition of the material, dentin, and interfacial area. The marginal adaptation of cements to dentin was assessed by confocal microscopy and the percentage of material penetration was calculated. An interfacial layer was evident in approximately 70% of SEM images in both MTA-Angelus and BIOfactor samples. The thickness of interfacial layer was significantly higher in HBSS than in distilled water for all groups. MTA Angelus resulted in the thickest interfacial layer in distilled water while Biodentine had the thickest interfacial layer in HBSS. Calcium levels within the BIOfactor MTA-dentin interface were higher than both dentin and cement. Dentin penetration was higher in BIOfactor MTA and silicon was evident in all material-dentin interfaces. All calcium silicate-based materials promoted the formation of an interfacial layer. BIOfactor MTA exhibited promising characteristics with its good marginal adaptation even though it presented a moderately thick interfacial layer. RESEARCH HIGHLIGHTS: A distinguishable interfacial layer was observed in most of the samples within the BIOfactor MTA, MTA-Angelus and Biodentine groups. The elemental constitution of the interfacial layer was different from that of the calcium silicate based materials.

A call for disciplined patience instead of crystalloid infusion for the trauma patient

LAY SUMMARY Bleeding trauma patients require resuscitation with blood rather than an infusion of salt solution. However, a short delay often occurs from the time a resuscitation provider calls for blood and its availability. When facing a bleeding trauma patient with life-threatening low blood pressure, providers feel pressure to give immediately available salt-containing fluids. These fluids may help increase a patient’s blood pressure but will also decrease the body’s ability to deliver oxygen to organs and may increase bleeding and shock. It is proposed that providers maintain disciplined patience and wait for blood to be available rather than transfusing saltwater solutions.

Screening adsorbent-working solution pairs for adsorption-driven osmotic heat engines based on experimental water adsorption isotherm database and machine learning

Osmotic heat engines have attracted increasing attention in harvesting ultra-low temperature waste heat. In order to fill the gap in the high-throughput computational screening of adsorbent-aqueous salt solution working pairs for adsorption-driven osmotic heat engines, an experimental water adsorption isotherm database is constructed and eight common salt-water solutions are selected to identify the high-performance work pairs with system energy efficiency as evaluation indicator. The relationship between adsorbent properties, adsorbent structure characteristics and system performance is systematically analyzed. Results revealed that high working capacity and moderate adsorption enthalpy of adsorbents and large osmotic coefficients of salts are beneficial to energy efficiency. Adsorbents with larger accessible surface area, moderate available pore volume and critical pore diameter are favorable. Furthermore, regression machine learning is employed for achieving fast and accurate prediction of the system energy efficiency to accelerate screening. Genetic algorithm is adopted to search for the best-performing working pair properties.

Change in rapid salting kinetics and characteristics of hen egg yolks

A study of the dynamics of egg yolk salting clarified the diffusion of salt and the resulting changes in yolk quality and thereby provided guidance for better control of the final product. The effects of different salt contents in the salting solution (between 16 and 24%) on the mass transfer kinetics and egg yolk quality were analyzed during rapid salting. The results for the egg yolks showed that the changes in weight and water concentration decreased with increasing salt mass fraction, while the NaCl change increased. An increase in the salt content in the salting solution increased the effective diffusion coefficient ( D e ) of NaCl. Low-frequency nuclear magnetic resonance (LF-NMR) spectroscopy showed that higher salt content in the solution improved the amount of water transferred. The salted egg yolks treated in the 20–24% salting solutions had higher hardness, cohesiveness, oil yield and sandiness than those treated in other salting solutions. The samples salted in 16% solution had the highest values of the egg yolk index and CIELAB colorspace dimensions a* and b*. An analysis revealed statistically significant correlations between oil yield, sandiness, texture and color with D e . Taking oil yield and sandiness as the main indexes and comprehensively considering other sensory characteristics showed that 20% NaCl was the most suitable salt water solution for the rapid salting of hen egg yolks. ● The mass transfer and quality change of egg yolks increased with the salt content. ● The effective diffusion coefficient ( D e ) increased with salt content from 20 to 24%. ● T 23 , egg yolk index, springiness, cohesiveness, a* and b* decreased with salt content. ● T 22 , oil yield, sandiness, hardness, chewiness and L* increased with salt content. ● Oil yield, sandiness, texture and color were significantly correlated with the D e .

Stability of Detonation Nanodiamond Colloid with Respect to Inorganic Electrolytes and Anionic Surfactants and Solvation of the Particles Surface in DMSO–H2O Organo-Hydrosols

In this article, the stability of sols of detonated nanodiamonds, DND, with positively charged colloidal particles, is studied in different salt solutions in water–dimethyl sulfoxide (DMSO) binary systems containing 95 vol.% organic solvent. Additionally, several CCC values are determined in 95 vol.% acetonitrile for comparison. The critical coagulation concentrations (CCC) are determined using the dynamic light scattering technique and the Fuchs function. As coagulators, NaCl, NaBr, NaNO3, NaClO4, Nan-C8H17SO3, and Nan-C12H25OSO3 are used. Comparison of the CCC values in DMSO–H2O and CH3CN–H2O with those obtained in water allows us to make some conclusions. The variations of these values in different solvents are explained in terms of good and poor interfacial solvation of colloidal particles, “structural” contribution to the interparticle interaction energy, lyotropic series for anions, and more or less pronounced adsorption of surfactants. The study of the stability of DND hydrosol in solutions of anionic surfactants with different hydrocarbon tail length demonstrated the crucial role of adsorption in the coagulation process.

Effect of saltwater on the mechanical properties of basalt/carbon/glass-epoxy hybrid composites

The impact of environmental conditions on the mechanical properties of composites is critical for various industries, particularly marine. The paper examines the effect of saltwater conditions on the mechanical properties of basalt, carbon, and glass fibers/epoxy hybrid composites. The composite samples were manufactured using Vacuum Assisted Resin Transfer Molding (VARTM) and then immersed in saltwater solution before tests. The tests were performed using Instron 8801 with 100 kilonewtons (kN) capacity. The environmental effects on the mechanical properties were supported by the Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis of the water. The ICP-OES analysis result shows a transfer of ions from the fiber to the saltwater solution. As a result, the mass gain of all the samples increases with the conditioning period, while the tensile and flexural properties show degradation. Moreover, the hybrid composites show a gradual failure mode compared with non-hybrid composites. In addition, the failure modes and morphological analysis of the failed test samples were presented. Delamination, explosive failure, and fiber breakage characterize the tensile failure mode of basalt/epoxy (BE) and its hybrids. However, the glass/epoxy (GE) and carbon/epoxy (CE) show fractures in two or three sections. In addition, compressive failure, tensile failure, shear failures, delamination, and fiber breakage were detected in the flexural samples.

Improving the mechanical performance of adhesively bonded CFRP composite joints exposed to harsh mediums with the reinforcement of boron nanostructures

In this study, the degradation in the strength of adhesively bonded carbon fibre composite joints exposed to different harsh mediums was improved with the addition of silane-modified BN and B4C nanostructures. For this purpose, modified BN and B4C nanostructures were added to the structural adhesive, and then composite plates were bonded with the new reinforced adhesives to produce single lap joints. The produced joints were aged 480, 960, and 1440 h in distilled water, saltwater, sulphuric acid, and ultraviolet light mediums. The mechanical properties of the joints were determined by the tensile test after aging. Moreover, liquid absorption and SEM analyses were performed to observe the structural change in the adhesives. The results revealed that adding nanostructures into the epoxy matrix positively decreases the absorption of distilled water, saltwater, and sulphuric acid solutions. It was also observed that the failure loads of joints decreased depending on the severity of the damage caused by the aging mediums. The joints bonded with BN and B4C nanostructures reinforced adhesives decreased the damage experienced by limiting the harmful effects of the mediums. After 1440 h of aging in the distilled water medium, the composite joints reinforced with BN and B4C nanostructures carried approximately 40% and 37.6% higher loads, respectively, compared to the neat joint. Similarly, as a result of the aging in the UV medium, BN and B4C reinforced joints carried approximately 48.3% and 40.9% higher loads, respectively, while these ratios were determined as 39.7% and 36.7%, respectively, for the saltwater medium.

Mathematical Simulation of Crystal Growing in Water-Salt Solutions

Mathematical Simulation of Crystal Growing in Water-Salt Solutions

Reproducible and Repeatable Generation of 4-He, γ-rays, and Heat in Light and Heavy Waters at Room Temperature

The extraordinary claim of observing nuclear fusion products and excess heat during heavy water electrolysis at room temperature was sensationalized in 1989. Unfortunately, it was rejected quickly by scientific communities. At the last attempt to access the accuracy of the previous works in this field, a Google-funded team tried to examine all reported works with their corresponding conditions to confirm the claimed results. Finally, they found that there was no reasonable proof of nuclear fusion reactions under the reported conditions. Here, we introduced a method to apply a unique triggering potential waveform to a simple two micro-shaft system in both heavy and light concentrated salinity waters which resulted in detecting 4-helium, gamma rays, and heat repeatedly and reproducibly. In this work, two types of nuclear fusion reactions were observed: 1) A D + D fusion reaction in potassium halide salt solutions in heavy water and 2) a new type of fusion reaction in carbon-containing salt solutions in both light and heavy waters. In the latter type, it was proved that the existence of carbon atoms in an anion structure is critical to observe the 4-helium, gamma rays, and heat.

Experimental and numerical investigation of specific behaviour of fluoride ions during filtration of pure salt water solutions with titania membrane

This work addresses the specific interactions between titania membrane and fluoride anions during ultrafiltration operation. In general, the salt transmission increases with salt concentration when pure salt-water solutions are ultrafiltrated, except for fluoride-based salts observed in our study, for which transmission decreased at low concentrations. This phenomenon was only observed with titanium dioxide membrane. A numerical tool based on a physical description of ionic mass transfer in porous material (generalized Nernst-Planck approach) was used to explore the modification-induced changes due to fluoride anions. Numerical investigations showed a modification of the electric charge of the membrane surface in the pore at low fluoride concentrations. This phenomenon screened the electric effect in a completely reversible way, and then enhanced the ion mass transfer through the porous membrane. These modifications can be explained by the substitution of oxygen atom (providing the surface electric charge) with a fluoride ion which was screening the electric charge and facilitated the ion transfer.

Water, saltwater, and concrete leachate solution effects on durability of ambient‐temperature cure carbon‐epoxy composites

AbstractWet layup carbon epoxy composites are extensively used for rehabilitation of civil infrastructure. This study focuses on foundation building for understanding durability of such materials through long‐term (up to 5 years) hygrothermal aging in water, saltwater, and concrete leachate, solutions. Moisture uptake is described using a two‐stage model incorporating diffusion and relaxation/deterioration parameters with the concrete leachate solution showing further transitions and the highest value of the relaxation/deteriorative coefficient. Glass transition temperatures decreased with an increase in moisture content reaching an initial minimum followed by fluctuations and small increases with an increase in the time of exposure. Immersion in concrete leachate results in the largest decrease. Tan δ height shows an initial decrease followed by an increase and then a continued decrease indicative of an initial plasticization and post‐cure followed by deterioration at the resin and fiber–matrix levels. Although short‐term response in mechanical properties shows differences with immersion in water having the least effect, solution type had very little difference on residual mechanical characteristics at the end of the 60‐month period of immersion. The results emphasize the need for further understanding of competing effects in ambient‐cured composites and of the need for longer term testing for determination of design factors.

A comparison of pre-coated stock antireflection coating lenses in terms of transmission, durability and quality

Background: Antireflection coatings (ARCs) applied to ophthalmic plastic lenses must have a good quality base hard coat for the ARC to adhere to. The hard coating must be durable so as not to crack, craze or peel under different atmospheric conditions. The purpose of ARC is also to increase the transmission of light through the lenses and eliminate reflections.Aim: The aim of this research was to compare the quality of eight different pre-coated ARC stock lenses in terms of light transmission and durability.Setting: The measurements were taken in the physics laboratory at the University of Johannesburg.Methods: Eight different stock ARC lenses were obtained from different lens suppliers. The performances were assessed by measuring the light transmission through each lens, exposure to chemicals such as salt–water solution and adhesion and abrasion tests to assess the quality of the coatings.Results: The performance and quality of the different lenses differed slightly in terms of hardness, durability and quality. The lenses also differed slightly in average transmission percentage. The difference between the control lens and the highest average percentage transmission was 4.8%, and the lowest average transmission was 2.2%. The lens that performed the best overall was Crizal Forte and the worst was Precision.Conclusion: Not all lenses have the same quality of ARC applied and durable qualities. Quality control should be carried out regularly in batches so as to maintain high standards set out by the different suppliers.

Surfactant membranes architecture and performance: Effect of HLB value and concentration of non-ionic surfactants

This paper discusses a pioneering work on the effect of hydrophilic-lipophilic balance (HLB) values and non-ionic surfactant concentrations on the performance, architecture i.e. morphology and molecular orientation of polyethersulfone/polyether glycol (PES/PEG 600) for surfactant membrane. PES surfactant membranes were developed through phase inversion fabrication technique with the addition of non-ionic surfactants Triton X-100 (TX100) and Tween 20 (T20) into the polymer solution during formulation. The results of the experimental data conducted showed that 2 wt% increase in the concentration of non -ionic surfactants resulted increased in pure water permeated (PWP) flux and salt solution flux. T20 at 3 wt%, the surfactant membrane reached an highest PWP level of around 1200.67 L/m2 × h while showing an highest flux obtained at 31,692 L/m2 x h. Analysis of membrane structure construction from the morphological results of 3 wt% TX100 membrane having lower HLB value yielded highest rejection at 99.7% and became a booster to produce fine membrane structure, subsequently producing high performance surfactant membrane.

Probing Nuclear Dipole Moments and Magnetic Shielding Constants through 3-Helium NMR Spectroscopy

Multinuclear NMR studies of the gaseous mixtures that involve volatile compounds and 3He atoms are featured in this review. The precise analyses of 3He and other nuclei resonance frequencies show linear dependencies on gas density. Extrapolation of the gas phase results to the zero-pressure limit gives the ν0(3He) and ν0(nX) resonance frequencies of nuclei in a single 3-helium atom and nuclei in molecules at a given temperature. The NMR frequency comparison method provides an approach for determining different nuclear magnetic moments. The application of quantum chemical shielding calculations, which include a more complete and careful theoretical treatment, allows the shielding of isolated molecules to be achieved with great accuracy and precision. They are used for the evaluation of nuclear moments, without shielding impacts on the bare nuclei, for: 10/11B, 13C, 14N, 17O, 19F, 21Ne, 29Si, 31P, 33S, 35/37Cl, 33S, 83Kr, 129/131Xe, and 183W. On the other hand, new results of nuclear moments were used for the reevaluation of absolute nuclear magnetic shielding in the molecules under study. Additionally, 3He gas in water solutions of lithium and sodium salts was used for measuring 6/7Li and 23Na magnetic moments and reevaluating the shielding parameters of Li+ and Na+ water-solvated cations. In this paper, guest 3He atoms that play a role in probing the electron density in many host macromolecules are also presented.

НОВЫЕ ИНГИБИТОРЫ СОЛЕОТЛОЖЕНИЙ НА ОСНОВЕ МОДИФИЦИРОВАННЫХ ОТХОДОВ ПОЛИЭТИЛЕНТЕРЕФТАЛАТА

For the first time, the synthesis of new scaling inhibitors – esters of phosphoric acids, based on the reactions of phosphorylation of hydroxyethylterephthalamide with polyphosphoric acid, was theoretically substantiated and experimentally carried out. The esterification with polyphosphoric acid of bishydroxyethyterephthalamide was carried out at a temperature of 130-140°C for 4-6 hours. Bishydroxyethyl terephthalamide is a product of the aminolysis of polyethylene terephthalate, including in the form of production waste or recycling of polyethylene terephthalate. Using 1 H-, 31P spectroscopy the structure and composition of new reagents were proved. The inhibitory activity of phosphoric acid esters of bishydroxyethyl terephthalamide was studied on model water-salt solutions. It has been established that inhibitors have complex actions in relation to carbonate and sulfate deposits. An effective amount to inhibit sulfate scale is 2-10 ppm, carbonate scale 10-30 ppm. The degree of inhibition reaches 100%. Inhibitors can be recommended to protect pipelines from scale deposits during oil transportation.

Nafion Swelling in Salt Solutions in a Finite Sized Cell: Curious Phenomena Dependent on Sample Preparation Protocol.

When a membrane of Nafion swells in water, polymer fibers “unwind” into the adjoining liquid. They extend to a maximum of about ~300 μm. We explore features of Nafion nanostructure in several electrolyte solutions that occur when the swelling is constrained to a cell of size less than a distance of 300 μm. The constraint forces the polymer fibers to abut against the cell windows. The strongly amphiphilic character of the polymer leads to a shear stress field and the expulsion of water from the complex swollen fiber mixture. An air cavity is formed. It is known that Nafion membrane swelling is highly sensitive to small changes in ion concentration and exposure to shaking. Here we probe such changes further by studying the dynamics of the collapse of the induced cavity. Deionized water and aqueous salt solutions were investigated with Fourier IR spectrometry. The characteristic times of collapse differ for water and for the salt solutions. The dynamics of the cavity collapse differs for solutions prepared by via different dilution protocols. These results are surprising. They may have implications for the standardization of pharmaceutical preparation processes.

Recovery of water and reusable salt solution from reverse osmosis brine in textile industry: A case study

Textile industry is one of the major water-consuming sectors; therefore, developing methods for reusing water is essential. Processes including reverse osmosis (RO) have gained momentum recently and been widely used. However, concentrated streams (brine) generated from RO must be managed properly. In this study, a pilot-scale brine treatment system containing ozone oxidation, nanofiltration (NF), RO and ion exchange (IEX) was developed and operated to recover a high quality process water and salt solution to be reused in dyeing processes. It was revealed that 77% of the water and 66% of the salt solution (as NaCl) can be recovered and brine discharge can be reduced. With full-scale operation for one year, it is possible to achieve cost-savings by 176,256 USD with 115,000 m3 reused water and by 37,000 USD with 680 tons of recovered NaCl. Recovery of brine makes it possible to achieve sustainable production and zero liquid discharge concepts.

An experimental study of displacement flows in stationary and moving annuli for reverse circulation cementing applications

We present an experimental study of buoyant displacement flows in vertical narrow centric/eccentric annular configurations, representing the oilfield primary cementing process, from a fluid mechanics perspective. In this study, we consider the reverse circulation cementing case, i.e. the case in which the cementing fluids are pumped down from the surface into the annulus and the in-situ fluids are taken through the casing or tubing. The fluid proxies used to represent the industrial fluids are miscible, with different rheological behaviours, i.e. salt-water (Newtonian), Xanthan (shear-thinning) and Carbopol (viscoplastic) solutions, and they have various density contrasts. Our dimensional analysis and systematic simplifications allow us to describe the flow using five dimensionless numbers: m (viscosity ratio), Fr (densimetric Froude number, quantifying effects of the density difference or buoyancy), Re (Reynolds number, quantifying the effects of the imposed flow rate), e (eccentricity) and f (reciprocation frequency). We examine the effects of the aforementioned parameters in stationary and moving annuli, wherein we change the frequency of the inner pipe reciprocation motion, over a fixed amplitude. Using mainly high-speed camera imaging techniques, we analyse displacement flow patterns and mixing between the fluids. We show that the density-stable or density-unstable configurations, the non-Newtonian effects, and the annulus eccentricity exert a significant impact on the displacement flow features, which we explain through a detailed comparison between Newtonian and non-Newtonian displacements. In addition, we demonstrate that an interplay between the yield stress and the annulus motion can remarkably change the displacement flow behaviour, particularly the wall residual layer thicknesses of the displaced fluid. Finally, we quantify the effects of different flow parameters on the leading front velocity, representing the displacement efficiency in the reverse circulation cementing.

Thermoresponsive Ionic Liquid/Water Mixtures: From Nanostructuring to Phase Separation.

The thermodynamics, structures, and applications of thermoresponsive systems, consisting primarily of water solutions of organic salts, are reviewed. The focus is on organic salts of low melting temperatures, belonging to the ionic liquid (IL) family. The thermo-responsiveness is represented by a temperature driven transition between a homogeneous liquid state and a biphasic state, comprising an IL-rich phase and a solvent-rich phase, divided by a relatively sharp interface. Demixing occurs either with decreasing temperatures, developing from an upper critical solution temperature (UCST), or, less often, with increasing temperatures, arising from a lower critical solution temperature (LCST). In the former case, the enthalpy and entropy of mixing are both positive, and enthalpy prevails at low T. In the latter case, the enthalpy and entropy of mixing are both negative, and entropy drives the demixing with increasing T. Experiments and computer simulations highlight the contiguity of these phase separations with the nanoscale inhomogeneity (nanostructuring), displayed by several ILs and IL solutions. Current applications in extraction, separation, and catalysis are briefly reviewed. Moreover, future applications in forward osmosis desalination, low-enthalpy thermal storage, and water harvesting from the atmosphere are discussed in more detail.