Proton-coupled electron transfer at SOFC electrodes.

Understanding the charge transfer processes at solid oxide fuel cell (SOFC) electrodes is critical to designing more efficient and robust materials. Activation losses at SOFC electrodes have been widely attributed to the ambipolar migration of charges at the mixed ionic-electronic conductor-gas interface. Empirical Butler-Volmer kinetics based on the transition state theory is often used to model the current-voltage relationship, where charged particles transfer classically over an energy barrier.

Operando Characterization and Theoretical Modeling of Metal|Electrolyte Interphase Growth Kinetics in Solid-State Batteries. Part I: Experiments.

To harness all of the benefits of solid-state battery (SSB) architectures in terms of energy density, their negative electrode should be an alkali metal. However, the high chemical potential of alkali metals makes them prone to reduce most solid electrolytes (SE), resulting in a decomposition layer called an interphase at the metal|SE interface. Quantitative information about the interphase chemical composition and rate of formation is challenging to obtain because the reaction occurs at a buried interface.

Operando Characterization and Theoretical Modeling of Metal|Electrolyte Interphase Growth Kinetics in Solid-State Batteries. Part II: Modeling.

Understanding the interfacial dynamics of batteries is crucial to control degradation and increase electrochemical performance and cycling life. If the chemical potential of a negative electrode material lies outside of the stability window of an electrolyte (either solid or liquid), a decomposition layer (interphase) will form at the interface. To better understand and control degradation at interfaces in batteries, theoretical models describing the rate of formation of these interphases are required.

Electric Fields and Charge Separation for Solid Oxide Fuel Cell Electrodes.

Activation losses at solid oxide fuel cell (SOFC) electrodes have been widely attributed to charge transfer at the electrode surface. The electrostatic nature of electrode-gas interactions allows us to study these phenomena by simulating an electric field across the electrode-gas interface, where we are able to describe the activation overpotential using density functional theory (DFT). The electrostatic responses to the electric field are used to approximate the behavior of an electrode under electrical bias and have found a correlation with experimental data for three different reduction reactions at mixed ionic-electronic conducting (MIEC) electrode surfaces (HO and CO on CeO; O on LaFeO).

Theory of the electrostatic surface potential and intrinsic dipole moments at the mixed ionic electronic conductor (MIEC)-gas interface.

The local activation overpotential describes the electrostatic potential shift away from equilibrium at an electrode/electrolyte interface. This electrostatic potential is not entirely satisfactory for describing the reaction kinetics of a mixed ionic-electronic conducting (MIEC) solid-oxide cell (SOC) electrode where charge transfer occurs at the electrode-gas interface. Using the theory of the electrostatic potential at the MIEC-gas interface as an electrochemical driving force, charge transfer at the ceria-gas interface has been modelled based on the intrinsic dipole potential of the adsorbate.

An unusual cause of a non-functioning stoma in an 87-year-old gentleman.

Gallstone ileus is a rare but significant cause of intestinal obstruction particularly among the elderly population. Symptoms are often vague and therefore a high suspicious index is required for successful diagnosis. In this report, we present the case of an 87-year-old gentleman with a background history of cholelithiasis and ileostomy for ulcerative colitis who was admitted with a 24-h history of his stoma not functioning.

Primary chemo-radiotherapy in the treatment of locally advanced and inflammatory breast cancer.

Background: The best management of large, diffuse or inflammatory breast cancers is uncertain and the place of radiotherapy and/or surgery is not clearly defined.

Methods: A cohort of 123 patients with non-metastatic locally advanced or inflammatory breast cancer 3 cm or more in diameter or T4, was treated between 1989 and 2006. All patients received primary chemotherapy followed by radiotherapy, 40 Gy in 15 fractions with 10 Gy boost.