A combined SNIFTIRS and XANES study of electrically polarised copper electrodes in DMSO and DMF solutions of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) ions

A SNIFTIRS (subtractively normalized interfacial Fourier transform infrared spectroscopy) and X-ray absorption spectroscopy (XAS) study of electrically polarized copper electrodes in six polar aprotic solvent-based systems is presented. In the systems investigated, i.e. dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) solutions containing pseudohalide species of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) codissolved with tetrabutylammonium perchlorate (TBAP), Cu was found to dissolve over a wide range of potentials to produce the corresponding Cu(I) pseudohalide and/or Cu(II) pseudohalide complex ion species. Insoluble deposited films were also observed at higher anodic applied potentials, thought to be CuSCN in the Cu/NCS⁻/DMSO or DMF systems, and solid K(SeCN)₃ in the Cu/NCSe⁻/DMSO or DMF systems respectively. The presence of the Cu(II) and/or Cu(I) oxidation states in complexes formed by polarization in Cu/pseudohalide ion systems in DMSO was clearly proven using XAS of cell solutions sampled after SNIFTIRS/electrical polarization experiments. In addition, Fourier transform infrared (FTIR) and X-ray absorption near edge spectroscopy (XANES) data obtained from model solutions prepared from mixing Cu(I) and/or Cu(II) salts with the respective pseudohalide ions in DMF and DMSO confirmed the speciation observed in the electrochemical experiments

Anodically polarized nickel electrodes in DMSO or DMF solutions of pseudohalide ions: IR spectroelectrochemical studies

A novel subtractively normalized interfacial Fourier transform infrared spectroscopic (SNIFTIRS) investigation of anodically polarized nickel electrodes in pseudohalide-containing DMF or DMSO solutions (i.e. OCN⁻, SCN⁻, SeCN⁻), in supporting electrolyte, tetrabutylammonium perchlorate (TBAP), is presented. In general, the data showed that nickel demonstrated irreversible anodic dissolution in all solutions studied at very high values of the applied potential, > +500 mV (AgCl/Ag). The predominant speciation of nickel in these systems was as complex ions consisting of Ni²⁺ ion complexed to pseudohalide ions and solvent molecules. Insoluble films and dissolved CO₂ were also detected, though mostly in the Ni/OCN⁻ systems studied. Ni(II)/pseudohalide complex ion species detected were modeled using solutions containing Ni²⁺ ion mixed with pseudohalide ion in different mole ratios. In general, the Ni/OCN⁻ electrochemical system behaved differently relative to those of Ni/SCN⁻ and Ni/SeCN⁻ due to the difference in colors observed in cell solutions after SNIFTIRS experiments which was mirrored in the model solutions. Ni(II)-cyanate species had a different, coordination geometry and gave a characteristic bright blue color due possibly to Ni(NCO)₄²⁻ ion while Ni(II) thiocyanate and selenocyanate complex ion species had octahedral coordination geometries containing solvent and one coordinated pseudohalide ion and formed greeny yellow solutions

Developments in the Youth Labour Market in Post-War Britain

This study aims to investigate post-war developments in the British youth labour market, with particular reference to both the behaviour of this group's unemployment through time and its distribution cross-sectionally. It is motivated by the concern expressed in virtually all quarters in recent years about the apparent failures of this particular market to provide an adequate introduction to working life for the young of the nation. This worry relates not only to the loss of current output that joblessness entails, but also to its potential longer term personal and social consequences

Performance of the Christchurch, New Zealand Cathedral during the M7.1 2010 Canterbury earthquake

The Catholic Cathedral is classified as a category 1 listed heritage building constructed largely of unreinforced stone masonry, and was significantly damaged in the recent Canterbury earthquakes of 2010 and 2011. In the 2010 event the building presented slight to moderta damage, meanwhile in the 2011 one experienced ground shaking in excess of its capacity leading to block failures and partial collapse of parts of the building, which left the building standing but still posing a significant hazard. In this paper we discuss the approach to develop the earthquake analysis of the building by 3D numerical simulations, and the results are compared/calibrated with the observed damage of the 2010 earthquake. Very accurate records were obtained during both earthquakes due to a record station located least than 80 m of distance from the building and used in the simulations. Moreover it is included in the model the soil structure interaction because it was observed that the ground and foundation played an important role on the seismic behavior of the structure. A very good agreement was found between the real observed damage and the nonlinear dynamic simulations described trough inelastic deformation (cracking) and building´s performance.University of AucklandPolytechnical University of Guadalajar

TransFormers for Extreme Environments: Projecting Favorable Micro-Environments Around Robots and Areas of Interest

Surviving Extreme Space Environments (EE) is one of NASAs Space Technology Grand Challenges; we propose a paradigm shift in addressing this challenge. TransFormers (TFs) transform a region of an extreme environment into a favorable micro-environment, projecting energy at the precise location where robots or humans operate. TFs often use shape transformation to control the energy projection

An X-ray absorption spectroscopy investigation of the coordination environment of electrogenerated Ni(ii)-pseudohalide complexes arising from the anodic polarization of Ni electrodes in DMSO solutions of NCO⁻ , NCS⁻ and NCSe⁻ ions

X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) were used to provide direct information in solution on the coordination state of electrogenerated products from anodically polarized nickel electrodes in pseudohalide-ion-containing dimethyl sulfoxide (DMSO) solvent (i.e. NCX⁻, X = O, S, Se) in the presence of a supporting electrolyte of tetrabutylammonium perchlorate (TBAP). Electrogenerated solutions and model solutions representative of the chemical speciation in electrolyzed systems (prepared by mixing Ni(II) and pseudohalide ion solutions in DMSO), were also examined. In general for Ni(II) interacting with NCS⁻ and NCSe⁻, the complex ion generated appears to be 6-coordinate [Ni(NCX)(DMSO)5]⁺, while EXAFS/XANES data of the Ni/cyanate system suggest an average coordination number of 5, which in reality is due to the electrogenerated solution containing a mixture of 4 coordinate (tetrahedral) [Ni(NCO)4]²⁻ and octahedral [Ni(DMSO)6]²⁺ species. These observations of the octahedral geometry for the Ni(II)/thiocyanate and Ni(II)/selenocyanate systems and 5-coordinate geometry in the Ni(II)/cyanate systems (being electrogenerated products of anodic polarisation of Ni in the DMSO-supported pseudohalide ion electrolytes) agree with the differences in colour observed between samples. EXAFS/XANES measurements combined with IR spectroelectrochemical analyses of solutions provide a versatile way of analyzing these electrochemical systems without the need for isolating compounds from the electrolyte