Concentrated Potassium Chloride Solutions Research Articles

Insight on the inhibitive property of potassium ion on the stability of shale: a diffuse double-layer thickness (\u03ba\u22121) perspective

It is believed that potassium ions reduce the hydration energy and swelling of clays and thus promoting stability to shales. This belief was made based on volumetric and linear expansion data obtained from shale and KCl solutions interactions. However, swelling data alone is not adequate to mitigate wellbore instability in shale. Such data must be incorporated with mechanical and physicochemical data for complete and accurate wellbore instability analysis.This paper presents clear experimental evidence showing that concentrated potassium chloride solutions tend to suppress shale swelling as higher concentration of potassium ions collapses the diffuse double layer of clay particles causing shale shrinkage which confirms the notion that the Debye length (κ−1) decreases as the ionic concentration increases.Results show that there exists a KCl concentration threshold above which shale’s compressive strength deteriorates significantly. This concentration threshold was found to hover around 5% by weight. The amount of water and ions uptake into shale was quantified using gravimetric measurements. Significant potassium ions invasion into shale was experimentally measured as KCl solution concentration increased which proved the leaky nature of shale’s membrane. The reduction of shale’s compressive strength seems to be well correlated with the amount of ions uptake into shale. Moreover, data suggests that shale’s compressive strength was not significantly impacted by swelling. It was possible to gravimetrically separate osmotic water from associated water as shale interacted with KCl solutions. Results suggest that osmotic water is responsible for shale swelling since it is unattached to ions which makes it free to move around inside shale. On the other hand, data suggest that associated water does not contribute to shale swelling as it is bound to potassium ions which makes it unfree to move around. It is fair to state, based on our experimental data, that osmotic water is responsible for shale swelling while associated water contributes to shale’s compressive strength alteration.

Adaptive behavior of clinicians in response to an over-constrained patient safety policy on the administration of concentrated potassium chloride solutions

In response to fatal accidents involving concentrated potassium chloride (KCl) solutions, the Japanese hospital accreditation body released a safety policy in 2004 requiring the use of foolproof diluted KCl solutions throughout hospitals. However, the policy caused difficulties in treating seriously ill patients in critical care settings who require concentrated KCl solutions promptly. Resilient health care (RHC) provides a theoretical perspective for understanding how work is achieved in complex healthcare systems. ‘Work-as-imagined’ (WAI), as it should be done, and ‘work-as-done’ (WAD), as it actually takes place, are core concepts for understanding performance adjustment among individuals. This study aimed to investigate WAD regarding the administration of KCl solutions in the environment changed by WAI according to the authoritative policy.In 2017, we sent questionnaires to 346 critical care physicians. Topics included types of KCl products available in their units, administration methods, need for concentrated KCl solutions, hospital policies, and physician opinions. The response rate was 30.3% (105/346). Thirty-five physicians (33.3%) used conventional products out of compliance with the safety policy. Among 95 physicians using foolproof products, 69 (72.6%) obtained concentrated solutions from the products in an unsafe manner. The gap between WAI and WAD necessitated performance adjustments by physicians that introduced a new risk of adverse events despite the use of safer products.The study demonstrated that RHC theory can be used to inform the development and improvement of patient safety policies. Policy makers need to understand WAD when intervening in complex adaptive systems such as health care.

Cation capture and overcharging of a hydrophobized quartz surface in concentrated potassium chloride solutions

The paper presents experimental data indicating interesting new phenomena related to overcharging of a hydrophobic surface in concentrated potassium chloride solutions. We attribute these data to cation complexation and capture of the cations by the hydrophobic surface. The analysis of the mechanism of the detected phenomena is based on capillary electrokinetic and wettability studies and confirmed by SEM data and XPS spectra. It was found that cation capture/complexation takes prolonged time, being associated with hydrolysis of Si-O bonds in hydrophobic molecules and affected by salt concentration. In addition, the time necessary for reversal of the sign of ζ-potential when solutions with lower salt concentrations are pumped through the hydrophobic capillary is much longer than that required to simply replace the solution inside the capillary.

Potentiometric Cells with Liquid Junctions: A Combined Analytical and Computational Study

It is known that the electromotive force (emf) of cells with transference is dependent on an integral involving electrical transport numbers, t i , and chemical potentials. However, the origin of this integral, the conditions under which it is valid, its properties and utility are not well understood. This article aims to clarify such aspects. A general emf equation is derived in a manner in which the integral arises from the entropy production due to diffusion. Five important properties of the equation are recognized: (1) invariance with respect to the reference frame for t i measurements, (2) redundancy of single-ion activities, (3) lack of a potential function for the integral when the number of independent t i is greater than 1, (4) irrelevance of any metric on the junction 3-D space, and (5) invariance with respect to the free-diffusion time. As an application, the emf equation is tested for calibration of cells with dissimilar electrodes and junctions between the saturated potassium chloride solution and hydrogen chloride solutions in a range of concentration. It is found that (1) the standard emf can be estimated with a precision of about 0.1 mV for accurate enough data sets, and (2) the free-diffusion model is more appropriate for the flowing junctions than the continuous mixture model, although the difference between the two models is slight. In similar systems with less concentrated potassium chloride solutions, the free-diffusion mass density profiles are found to bear a sign of convective instability, because of which previously reported steady emfs for such cells may pertain to a changed solution composition in one of the two half-cells.

Development and characterization of glass matrix composites as porous coating film of a solid state reference electrode

For protection against leaching of the electrolyte reservoir of a solid state reference electrode a porous covering film was prepared and characterized. The porous covering film is based on a glass matrix composite and fired at 400 °C according to the thick-film-based structure of the reference electrode. Based on stability investigations on low sintering glasses in the range of pH 1.68 to pH 9.18 and in various concentrated potassium chloride solutions, a suitable zinc borate glass was selected. Using this glass and Al2O3 or ZrO2 oxide powders, various glass matrix composites were prepared and their sintering behavior was investigated in dependence on the amount of crystalline fraction up to 45 vol%. The shrinkage was measured by heating microscopy of powder compacts of cylindrical shape. In addition composite films on ZrO2 substrates screen-printed and at 400 °C fired were characterized in terms of their porosity by means of micro structural analysis and electrochemical deposition of copper. According to these investigations, suitable composites were selected as porous covering materials for the reference electrode and were tested therefore. The electrochemical characterization showed that the solid-state reference electrodes with porous covering films have a very good performance compared to conventional reference electrodes.

The introduction of safe practices for the administration of potassium chloride in hospitalised patients

BackgroundIncorrect intravenous administration of concentrated potassium chloride (KCl) solutions is potentially lethal. The Quality Agency for the Spanish National Health System has recommended safe practices to reduce this risk.PurposeTo describe...

Electrochemical transport properties of a cone-shaped nanopore: revisited

There are reports in the literature that a single cone-shaped nanopore generated in a polymer foil separating two equally concentrated dilute aqueous potassium chloride solutions can reach high and low stationary electrical conductivity states respectively depending on the sign of the applied electrical potential. On the basis of published data it has been argued (D. Woermann, Phys. Chem. Chem. Phys., 2003, 5, 1853) that this phenomenon can be understood in terms of a well established model describing the electrochemical transport properties of polyelectrolyte membranes (“model of the membrane with narrow pores”). In the present contribution experimental evidence is presented which gives strong support to these arguments using a model system. Based on the “model of the membrane with narrow pores” a composite membrane is constructed mimicking the structure and electrochemical function of an ensemble of conical nanopores. It is found that the characteristic electrochemical transport property of the composite membrane is that of a cone-shaped nanopore.

Rapid Correction of Hypokalemia: A Note of Caution

To the Editor — Kruse and Carlson 1 recently reported the results of their interesting study regarding the safety and efficacy of rapidly infusing concentrated potassium chloride solutions for the treatment of hypokalemia. They concluded that such an approach can be employed safely when administered cautiously in an intensive care unit. However, I believe that this conclusion may be premature. Due to the retrospective nature of the study, frequent serial serum potassium concentrations were not available during and after the infusions. Indeed, in some patients postinfusion serum samples were first obtained as late as 12 hours after completion of the infusion, and the majority were collected within 4 hours. This is an important shortcoming of the study. Cellular uptake of potassium loads provides the major early defense against hyperkalemia, particularly in patients with renal failure. 2 This cellular uptake of potassium, as well as its subsequent urinary excretion, is a

Electrical double layer studies of thiourea in concentrated potassium chloride solutions

Electrical double layer studies of thiourea in concentrated potassium chloride solutions

Electrical double layer studies of thiourea in concentrated potassium chloride solutions

Electrical double layer studies of thiourea in concentrated potassium chloride solutions

The heat of dehydration of concentrated sodium chloride and potassium chloride solutions

The molar heats of dehydration, ΔH¯dehyd., of concentrated sodium chloride and potassium chloride solutions were measured with a differential scanning calorimeter in the scanning and isothermal modes. The overall ΔH¯dehyd. was found to be 44.5 and 44.3 kJ mole−1 H2O for NaCl and KCl solutions respectively. There is an astonishing difference between concentrated NaCl and KCl solutions in the way water is lost. The number of fractions of heat dehydration were 2 for NaCl and 3 for KCl. The excess ΔH¯dehyd. was about 10 kJ mole−1 H2O for fraction II of NaCl, and 17 and 55 kJ mole−1 H2O for fractions II and III, respectively, of KCl.

Spike train structure following application of nociceptive potassium chloride solutions to the cat saphenous nerve

The structure of the spike train coding the nociceptive signal was investigated by a cross-correlation method. The action of nociceptive solutions of potassium chloride (125–1000 mM) on the saphenous nerve caused excitation of both myelinated and nonmyelinated fibers. The density of the spike train increased during the action of the stimulus up to a threshold sufficient for the appearance of nociceptive reflexes. The maximum of these reflexes coincided with the appearance of synchronous pulsations of discharges in the group of unmyelinated fibers. The nociceptive signal evoked by direct action of highly concentrated potassium chloride solutions on the nerve is thus coded by a high density of the spike train generated by the nerve fibers. Synchronous pulsations may be present in the spike train under these circumstances.

Analysis of Porous Electrodes with Sparingly Soluble Reactants: II . Variable Solution Properties, Convection, and Complexing

The galvanostatic operation of flooded porous electrodes employing metal/metal salt couples is analyzed. A model is developed for a single, circular pore configuration which accounts for the effects of differing equivalent volumes of the solid reactants. The model also includes effects of variation in solution properties and effects of complexing of the sparingly soluble salt with the bulk electrolyte anion. The couple in concentrated aqueous potassium hydroxide and the couple in concentrated potassium chloride solutions are considered. Overpotential is computed as a function of time for solid‐ film and solution‐diffusion versions of the model. The solid film model shows a linear overpotential‐time relationship and nearly uniform current distribution. The solution‐diffusion model shows a variety of overpotential‐time curves, based on different physical parameters. In general, anodic failure is caused by blockage of pores or by complete coverage of the metal surface by product crystallites. Cathodic failure is caused by low mass transport which leads to limiting currents in the electrode. The solution‐diffusion model may generate extremely nonuniform current distributions, often with maxima inside the pore. These persistent nonuniform current distributions are important in terms of the analysis of cycling behavior.

Activation of Medullary Neurons by Noxious Stimuli Applied to the Teeth

Nerve impulse activity was recorded from the descending tract of the trigeminal nerve before and after application of certain noxious stimuli to the exposed dentin of teeth. Heat, electric shocks, concentrated potassium chloride solutions, and negative pressure increased the firing frequency of a majority of the neurons monitored.

Properties of the Electrical Double Layer in Concentrated Potassium Chloride Solutions

Properties of the Electrical Double Layer in Concentrated Potassium Chloride Solutions