Štúdium vplyvu chloridov a bromidov na kritickú micelovú koncentráciu a parciálny mólový objem kvartérnej amóniovej soli

The critical micelle concentration (CMC) of the selected surfactant belonging to quaternary ammonium salts with chemical designation N,N-dimethyl-N-(3-((1R,5S)-1,8,8-trimethyl-2,4-dioxo-3-azabicyclo[3.2.1]octane-3yl)propyl)hexadecane-1-amine bromide was determined. Simultaneously, the effect of the addition of various concentrations of NaCl, KCl, NaBr, and KBr salts on the CMC value of the substance was observed and compared with those obtained in an aqueous solution at T = 296,15 K. Based on the results obtained, it was concluded that NaCl and KCl salts decreased the critical micelle concentration, while NaBr and KBr salts did not support micellization and CMC values therefore increased. In the case of solutions of a substance in the salt environment, when compared to the substance's solution in distilled water, a decrease in partial molar volume was observed. From the concentration density dependencies of the substance, an ionization degree of α was determined. Finally, the molar Gibbs energy ∆G° was also calculated and found negative for all salt solutions, while increase with their increasing concentration.

The application of vapour equilibrium technique to control suction to study the shrinkage and water retention of compacted Claystone-Bentonite mixtures

Understanding soil shrinkage and retaining water is essential for learning more about the possibility of cracking of liner. Moreover, the factors that influence it are also important to know to improve the material tested as hazardous waste liners. The vapour equilibrium technique is widely used to control suction of compacted soils experiencing drying-wetting phenomena. It is considered to be inexpensive, simple, and has the ability to adequately control the suction applied to soil samples. This paper, therefore, describes its application in studying the shrinkage and water retention in compacted claystone-bentonite mixtures. This involved using five saturated salt solutions including potassium sulphate (K2SO4), potassium chloride (KCl), sodium chloride (NaCl), potassium carbonate (K2CO3), and magnesium chloride (MgCl2.6H2O). The sample was allowed to be in equilibrium with the relative humidity salt solution and a calliper was used to measure the dimensions every day up to when this was achieved. The results showed the bentonite in the mixture affects the amount of shrinkage and water retention while the sample’s initial moisture content was also found to be very influential on the magnitude of the primary and residual shrinkage. Moreover, the sample’s ability to hold water was almost the same without differentiating the initial water content at a total suction of more than 41084.91 kPa.

Anion-Cation Contrast of Small Molecule Solvation in Salt Solutions

Salts are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we...

Heat to Hydrogen by RED—Reviewing Membranes and Salts for the RED Heat Engine Concept

The Reverse electrodialysis heat engine (REDHE) combines a reverse electrodialysis stack for power generation with a thermal regeneration unit to restore the concentration difference of the salt solutions. Current approaches for converting low-temperature waste heat to electricity with REDHE have not yielded conversion efficiencies and profits that would allow for the industrialization of the technology. This review explores the concept of Heat-to-Hydrogen with REDHEs and maps crucial developments toward industrialization. We discuss current advances in membrane development that are vital for the breakthrough of the RED Heat Engine. In addition, the choice of salt is a crucial factor that has not received enough attention in the field. Based on ion properties relevant for both the transport through IEMs and the feasibility for regeneration, we pinpoint the most promising salts for use in REDHE, which we find to be KNO3, LiNO3, LiBr and LiCl. To further validate these results and compare the system performance with different salts, there is a demand for a comprehensive thermodynamic model of the REDHE that considers all its units. Guided by such a model, experimental studies can be designed to utilize the most favorable process conditions (e.g., salt solutions).

Synthesis and characterization of novel thermo- and salt-sensitive amphoteric terpolymers based on acrylamide derivatives

A novel linear amphoteric terpolymers based on neutral monomer — N-isopropylacrylamide (NIPAM), ani- onic monomer — 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), and cationic mono- mer — (3-acrylamidopropyl) trimethylammonium chloride (APTAC) were synthesized by free-radical polymerization in aqueous solution and characterized by methods of 1H NMR and FTIR spectroscopy, TGA, GPC, Dynamic light scattering (DLS) and zeta-potential. The thermal and salt sensitivity of amphoteric ternary polymers of various compositions, particularly, [NIPAM]:[AMPS]:[APTAC] = 90:2.5:7.5; 90:5:5; 90:7.5:2.5 mol.% were studied in aqueous and aqueous-salt solutions in the temperature range from 25 to 60 C and at the NaCl ionic strength  interval from 10–3 to 1M. It was found that due to hydrophobic/hydrophilic balance, the temperature dependent conformational and phase change of macromolecular chains becomes sensitive to salt addition and allows the fine-tuning of the phase transition. In aqueous and aqueous-salt solutions, the average hydrodynamic size of amphoteric terpolymers is varied from 8 to 300 nm exhibiting bimodal distribution at room temperature. The number average (Mn) and weight average (Mw) molecular weights, polydispersity index (PDI), and zeta-potentials of amphoteric terpolymers in aqueous solu- tions were determined

Crystallogenesis of bioliquid in the homoeopathy

The term “crystallogenesis” was primarily mentioned in 1730. I. Newton in his research “Optics”described a phenomenon of regular structure formation from salt solutions. The latter proved to be the origin of nowadays biocrystallography. Later crystallography has been also applied in pharmacy (medication synthesis) and forensic medicine (toxicology). Moreover, a number of clinically oriented works on crystallography have been issued. This method is simple and safe for investigated people and animals. The purpose of this new medico-biological science is to discover crystallogenesis mechanisms and further to work out the criteria for estimation of various substrates bioinformation and biocrystallisation management on the basis of up-to-date accomplishments in the homoeopathy.

Perioperative infusion therapy

Perioperative infusion support of surgical patients is the main and non-alternative element of treatment. At the same time, the tactics of infusion therapy continues to be the subject of study. Ideas about the optimal quantitative and qualitative composition of the fluid transfused to patients are being revised as ideas about the pathogenesis of critical conditions evolve. The basis of pathogenetic analysis of compensatory hemodynamic capabilities, as a point of application of infusion treatment, previously consisted mainly of invasive monitoring techniques, replaced in recent years by the control of routine parameters with proven high correlation with invasive ones. In current studies devoted to the problems of infusion correction of hemodynamic abnormalities, the most discussed issues are the applicability of isotonic and balanced polyionic crystalloids, less often colloidal solutions in various clinical situations, and the results of such studies do not always allow to unambiguously determine the choice of infusion media, and sometimes simply incomparable. Some researchers advocate the use of isotonic crystalloids, some works prove the best effectiveness of balanced salt solutions. With the volumes of treatment corresponding to the perioperative period, in most studies there are no differences in the effectiveness of the main composite groups of crystalloids at all. We see the reason for this in the peculiarities of randomization methods, when statistical limitations do not allow us to avoid discrete data analysis: their comparative grouping occurs according to the principle of selecting a target parameter, and all the others are classified as auxiliary or secondary. It seems to us that the involvement of arrays of data obtained in real clinical practice as a result of a combination of local theoretical and empirical ideas about corrective treatment regimens correlated with their effectiveness could smooth out the inconsistency of the results of such studies, especially since clinicians have a sample with a volemic load at their disposal, allowing them to predict the hemodynamic reaction of the patient's body to infusion and a set of routine parameters for more fine-tuning of therapy.

On saline infusion, clonus, molecules and forgotten scientists: Who was Dr Julius Sander (1840–1909)?

Zitterbewegungen des Fusses bei Dorsalflexion (shaking movements of the foot upon dorsal flexion) were observed independently from each other and described in the same issue of a German peer reviewed journal by Carl Westphal (1833–1890) at the Charité in Berlin and by Wilhelm Erb (1840–1921) in Heidelberg. While Westphal used the term Fussphaenomen, Erb is credited with coining the term clonus for the phenomenon. Both scientists are immortalized by various eponyms acknowledging their respective contributions to science. Little is known however about Julius Sander (1840–1909), in those days resident at Charité, who noticed the phenomenon and presented it to his superiors, Wilhelm Griesinger (1817 −1868) and Westphal. In addition to such observations, Sander made original contributions in resuscitation physiology while working with Hugo Kronecker (1839–1914). With Kronecker, Sander published observations on life saving transfusions with inorganic salt solutions in dogs “ Bemerkung über lebensrettende Transfusion mit anorganischer Salzlösung bei Hunden” a very early work on isovolemic fluid resuscitation. The purpose of this communication is to highlight Sander's scientific contributions and to shed some light on his life, of which a German Lexicon stated that after 1870 no information on him can be ascertained anymore.

Evaluation of In-Situ Generation of Nitrogen Gas for Foam Applications using Two Salt Solutions

Foams are used in many oil and gas applications including conformance control during EOR processes, fracturing, and acidizing operations. Foams are defined as dispersions of gas bubbles into a continuous liquid phase. Typically, foams are generated when an injection gas such as nitrogen, carbon dioxide, or flue gas is mixed with an injection fluid containing a foaming agent. This method, however, requires a gas source to be present for foams to be generated. The objective of this study is to evaluate a new alternative technique for foam generation using two salt solutions. Nitrogen gas is generated as a result of the reaction of the two salt solutions at specific conditions. This generated nitrogen gas is then used for foam generation in porous media. The foam generated using the two salt solutions is tested in a microfluidic device (rock-on-a-chip) to study the gas mobility reduction in porous media. A Foam rheometer apparatus is also used to measure foam apparent viscosity when the two salt solutions are mixed with a foaming agent. The results are compared with those obtained when nitrogen gas is injected into the system independently in the absence of the two salt solutions. Results reveal that the amount of added salts significantly impact the produced nitrogen volume. Additionally, the test conditions especially the temperature, significantly impacts the reaction rate. The rate of nitrogen gas generation is directly proportional to the temperature when tested at 25-80°C. In addition, experiments demonstrate that the foams generated using the two salt solutions reaction have almost identical characteristics as those produced when nitrogen gas is injected into the foam rheometer apparatus independently. Both methods generate the same foams with comparable foam apparent viscosity. In the microfluidic system, the foam obtained using the two salt solutions in the presence of a foaming agent shows excellent resistance to gas flow and subsequently exhibit large gas mobility reduction. This experimental study, for the first time, confirms the ability of the two salt solutions reaction to generate nitrogen gas spontaneously upon contact under certain conditions. The generated gas is used to generate foams in the presence of a foaming agent. This newly proposed technique of foam generation could significantly impact many oil and gas operations including conformance control during EOR processes, fracturing, and acid stimulation operations.