Contrasting Surface Behavior of Rh (111) and Pt (111) Electrodes

Low energy electron diffraction and voltammetric measurements of the Rh(lll) electrode were conducted and compared with the corresponding surface and electrochemical characteristics of Pt (111). Rhodium is unstable upon exposure to water vapor or liquid water, but retains its well-defined character after immersion to aqueous media. This is reflected in the voltammetric behavior of the clean surface, as well as the manner in which carbon monoxide and iodine are adsorbed from solution. That is, a monolayer of an oxygen-containing species, assembled into (2X2) surface structure, can either be reduced by the voltammetric treatment or replaced by adsorbing solution components without causing system disorder. The voltammetry of the Rh (111) electrode, while exhibiting the main features of several metallic single crystal surfaces, differs significantly from that of platinum electrodes normalized to the same 2D geometry. From the voltam- me\u27ric behavior, it is concluded that adsorption of high energy hydrogen is not taking place on Rh (111). Equally important, the packing density and the surface structure of the Rh(lll) — CO differs from its Pt(lll) — CO analog. While iodine chemisorption from the gas phase leads to the development of several surface structures known from the corresponding platinum work, preferential formation of the_Pt (111) (V3 X V3)R30°—I structure against the Pt(lll)(V7X V7)R19.1°—I was demonstrated. Both electronic and structural factors contribute to the contrasting surface behavior brought to focus in this work

The neutral real interest rate: An updated view of r*

The neutral real rate of interest (r*) is a key variable for assessing the tightness of monetary policy. The neutral real interest rate has by all accounts fallen substantially over the past three decades, amid slowing productivity growth, an ageing population, increased inequality and increased demand for safe and liquid assets along with lower investment demand. Updated model estimates and long-term market rates support Norges Bank’s assessment that the neutral real money market rate lays between -0.5 and 0.5 percent. Going forward, a further rise in life expectancy might suggest a continued very low r*, while increased public investment in defence and the climate transition, as well as the phasing out of asset purchase programmes by the large central banks may pull up on r*.publishedVersio

Integrin-mediated adhesion promotes centrosome separation in early mitosis

Integrin-mediated adhesion to the extracellular matrix is a key regulator of the cell cycle, as demonstrated for the passage of the G1/S checkpoint and the completion of cytokinetic abscission. Here, integrin-dependent regulation of the cell cycle in G2 and early M phases was investigated. The progression through the G2 and M phases was monitored by live-cell imaging and immunofluorescence staining in adherent and non-adherent fibroblast cells. Non-adherent cells, as well as adherent cells lacking FAK activity due to suppressed expression or pharmacological inhibition, exhibited a prolonged G2 phase and severely defect centrosome separation, resulting in delayed progress through the early mitotic stages. The activation of the critical mitotic regulator PLK1 and its indirect target Eg5, a kinesin-family motor protein driving the centrosome separation, were reduced in the cells lacking FAK activity. Furthermore, the absence of integrin adhesion or FAK activity destabilized the structural integrity of centrosomes and often caused detachment of pericentriolar material from the centrioles. These data identify a novel adhesion-dependent mechanism by which integrins via FAK and PLK1 contribute to the regulation of the cell cycle in the G2 and early M phases, and to the maintenance of genome integrity

Den nøytrale realrenten: Et oppdatert syn på r*

Den nøytrale realrenten (r*) er en sentral størrelse for å kunne vurdere stramheten i pengepolitikken. Den nøytrale realrenten har etter alt å dømme falt betydelig de siste tre tiårene, drevet av avtakende produktivitetsvekst, aldring av befolkningen, økt ulikhet, økt etterspørsel etter sikre og likvide aktiva sammen med lavere investeringsetterspørsel. Oppdaterte modellestimater og lange markedsrenter støtter oppunder Norges Banks vurdering av at nøytral reell pengemarkedsrente ligger mellom -0,5 og 0,5 prosent. Fremover kan videre økning i forventet levealder trekke i retning av fortsatt svært lav r*, mens økte offentlige investeringer i forsvar og klimaomstilling og nedfasing av aktivakjøpsprogrammer hos de store sentralbankene kan bidra til å trekke opp r*.publishedVersio

Variational multiscale approximation of the one-dimensional forced Burgers equation: the role of orthogonal subgrid scales in turbulence modeling

This is the accepted version of the following article: [Bayona C, Baiges J, Codina R. Variational multi-scale approximation of the one-dimensional forced Burgers equation: the role of orthogonal subgrid scales in turbulence modeling. Int J Numer Meth Fluids. 2018;86:313–328. https://doi.org/10.1002/fld.4420], which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/fld.4420/fullA numerical approximation for the one-dimensional Burgers equation is proposed by means of the orthogonal subgrid scales–variational multiscale (OSGS-VMS) method. We evaluate the role of the variational subscales in describing the Burgers “turbulence” phenomena. Particularly, we seek to clarify the interaction between the subscales and the resolved scales when the former are defined to be orthogonal to the finite-dimensional space. Direct numerical simulation is used to evaluate the resulting OSGS-VMS energy spectra. The comparison against a large eddy simulation model is presented for numerical discretizations in which the grid is not capable of solving the small scales. An accurate approximation to the phenomena of turbulence is obtained with the addition of the purely dissipative numerical terms given by the OSGS-VMS method without any modification of the continuous problem.Peer ReviewedPostprint (author's final draft

Electrochemical Reduction of Perchlorate Ions

The electrochemical reduction of perchlorate ions is surveyed in the light of experimental results. The indications of the occurrence of perchlorate reduction in voltammetry, chronoamperometry, and in experiments applying the radiotracer method, the electrochemical bending beam technique, and impedance spectroscopy are presented. Some possible mechanisms of the complicated reduction processes are discussed. Environmental aspects and some methods for perchlorate removal and wastewater treatment are briefly summarized