Negative sulfur-based electrodes and their application in battery cells: Dual-ion batteries as an example

Journal of Solid State Electrochemistry - In this work, a cell concept comprising of an anion intercalating graphite-based positive electrode (cathode) and an elemental sulfur-based negative...     

Injection of large-volume samples into wide-bore capillary columns

Some parameters (injected sample volume and the completeness of sample transfer) in the injection of large-volume gas-vapor and liquid samples into a wide-bore capillary column with intermediate sorption preconcentration were examined. It was demonstrated that this sample injection technique can be used in analytical practice.     

Positive and dead core solutions of singular BVPs for third-order differential equations

The paper discusses the existence of positive and dead core solutions of the singular differential equation (?(u^″))^′=λf(t,u,u^′,u^″) satisfying the boundary conditions u(0)=A, u(T)=A, min{u(t):t∈[0,T]}=0. Here λ is a nonnegative parameter, A is a positive constant and the Carathéodory function f(t,x,y,z) is singular at the value 0 of its space variable y.     

Computer-assisted proofs of special function identities related to Poisson integrals

As a by-product of his work, E. Symeonidis obtained in (Comment. Math. Univ. Carol. 44(3):437–460, 2003) indirect proofs of two interesting special function identities involving Gegenbauer polynomials. In (Muldoon, 2004 ) the question of direct proofs was posed. We answer this question by presenting proofs obtained with the help of computer algebra algorithms based on WZ theory.     

Lehmer -tuples

Generalizing a classical problem of Lehmer, in this paper we provide an asymptotic result for the number of Lehmer -tuples.

     

The heat equation with time-independent multiplicative stable Lévy noise

We study the heat equation with a random potential term. The potential is a one-sided stable noise, with positive jumps, which does not depend on time. To avoid singularities, we define the equation in terms of a construction similar to the Skorokhod integral or Wick product. We give a criterion for existence based on the dimension of the space variable, and the parameter p$p$ of the stable noise. Our arguments are different for p<1$p<1$ and p?1$p?1$.     

In vitro permeation of chromium species through porcine and human skin as determined by capillary electrophoresis–inductively coupled plasma–sector field mass spectrometry

Since the species that trigger chromium allergy are not yet known, it is important to gain more of an insight into the mechanism of chromium transport through the skin and into the relationship between chromium allergy and chromium species. In vitro permeation studies with porcine and human skin were performed using a Franz static diffusion cell. Investigations attempted to elucidate (i) which Cr compounds are able to permeate through skin, (ii) the influence the Cr concentration in the donor solution has on the Cr permeation, and (iii) the effect that the time of exposure to the donor solution has on Cr permeation. Capillary electrophoresis hyphenated to inductively coupled plasma–sector field mass spectrometry (CE–ICP–SFMS) was used to separate and quantify the Cr species in the receptor fluid. 50 mmol L⁻¹ phosphate buffer (pH 2.5) was used for CE separation, and two different electrophoretic runs were carried out (in the positive and negative modes). Pneumatic nebulization (PN)-ICP-SFMS was used in order to quantify the total amount of Cr absorbed by the skin after microwave-assisted acid digestion of the tissue. Cr(VI) was found to pass most easily through the skin. Nevertheless, Cr(VI) was also shown to be absorbed more efficiently by the skin than Cr(III), an observation attributed to a more pronounced rejection of the positively charged Cr(III) ions by the skin barrier. These results were in good agreement with in vitro permeation studies previously reported in the literature in which other analytical techniques were used. Differences observed in the permeation of Cr following the application of aqueous Cr donor solutions and Cr-containing simulated sweat donor solutions are also described.