Galvanostatic Intermittent Titration Technique Reinvented: Part II. Experiments

Following a critical review of the galvanostatic intermittent titration technique in Part I, here we experimentally demonstrate how to extract chemical diffusivity with a modified method. We prepare dense bulk samples that ensure diffusion-limitation. We utilize the scaling with t relax + τ − t relax (t relax: relaxation time; τ: pulse duration), avoiding problems with composition-dependent overpotentials. The equilibrium Nernst voltage is measured separately using small porous particles. This separation between the diffusion measurement and the titration procedure is critical for performing each measurement in a reliable setting. We report the chemical diffusion coefficients of LixNi1/3Mn1/3Co1/3O2 and their activation energy. We extract ionic conductivity and compare it with total conductivity to confirm ion-limitation in chemical diffusion. The measurements suggest that the time scale for diffusion in typical Li-ion battery particles could be much shorter than that of the intercalation/deintercalation processes at the particle surface (Biot number less than 0.1).

Development of the methods for determination of the active components in acidic and alkaline detergents

The goal of the study is to develop methods for determination of the active components in acidic and alkaline detergents of complex composition. The objects of analysis are acidic (KATELON 202 – 208) and alkaline (KATELON 111 – 115) detergents of complex composition, which, in addition to easily detectable components (KOH and/or NaOH, HNO3, and H3PO4), contain weak organic acids (lactic, glycolic, acetic), including polybasic acids — aminotrimethylenephosphonic and diethylenetriaminepenta (methylenephosphonic) acids or salts — tetrasodium salt of glutamic acid N,N-diacetate, trisodium salt of methylglycine diacetic acid. An acid-base potentiometric titration was carried out for each of the listed objects and calculation formulas were derived to determine the concentration of the active substances (except for KATELON 115) in terms of nitric or phosphoric acid for acidic detergents or sodium or potassium hydroxide for alkaline detergents, respectively. A specific titration procedure (with indication of the sample weight, the pH value at the end of titration and corresponding calculation formula) is given in the application data sheet for each detergent along with the metrological characteristics of the methods.

The Influence of Probability Discounting on Escalation in Information Technology Projects

An experimental study was conducted with 17 experienced information technology (IT) project decision-makers. Each participated in a computer based simulation where they had to choose whether to continue an ongoing IT project despite negative feedback, (called escalation of commitment), or abandon it and sell the project as is. A titration procedure for sales price was manipulated over seven probability conditions for success of the project. The switching points where each participant would choose to sell the project instead of continuing development was determined, and probability discounting factors were calculated. The median switching point of the participant's subjective values of the project fit a hyperbolic discounting function well. An escalation factor was calculated and the results indicate that several participants in the study showed signs of escalation. These data demonstrate that the discounting framework may be a viable approach to understand the phenomenon of escalation in IT projects.

Determination of Quaternary Ammonium Compounds by Potentiometric Titration with an Ionic Surfactant Electrode: Single-Laboratory Validation

A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 11000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples.