Cationic and neutral ruthenium(II) complexes containing both arene or Cp* and functionalized aminophosphines. Application to hydrogenation of aromatic ketones

Hydrogen transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. For this aim, a series of novel Ru(II) complexes with the P-N-P ligands were synthesized starting from the complex [Ru(η⁶-p-cymene)(μ-Cl)Cl]₂ or [RuCp*Cl(COD)]. The complexes were fully characterized by analytical and spectroscopic methods. ³¹P-{¹H} NMR, DEPT, ¹H-¹³C HETCOR or ¹H-¹H COSY correlation experiments were used to confirm the spectral assignments. Complexes 5, 6 and 7 catalyze the transfer hydrogenation of acetophenone derivatives to 1-phenylethanol derivatives in the presence of iso-PrOH as the hydrogen source. Catalytic studies showed that all complexes are excellent catalytic precursors for the transfer hydrogenation of acetophenone derivatives in 0.1 M iso-PrOH solution. Notably 5 acts as an excellent catalyst giving the corresponding alcohols in excellent conversions up to 99% (TOF ≤ 492 h⁻¹).     

Comparison of pre-irradiation and mutual grafting of 2-chloroacrylonitrile on cellulose by gamma-irradiation

Radiation-induced graft polymerization is one of the best methods for obtaining materials with new properties. In this work, radiation grafting of 2-chloroacrylonitrile to cellulose by mutual and pre-irradiation grafting methods was investigated. The grafting yield was enhanced by applying the emulsion grafting method. The grafting yield determined in the above systems was observed as 27% at highest and 6% at lowest. The effects of concentration of monomer, reaction time and reaction temperature on grafting yield were studied. Evidence of grafting has been based on the comparative studies of cellulose and grafted cellulose by infrared spectroscopy, thermal analysis and contact angle measurement. Grafting enhances thermal stability of cellulose backbone.     

Hospital efficiency with risk adjusted mortality as undesirable output: the Turkish case

We analyze the operational performance of 202 Turkish rural general hospitals. To help improve performance on both input and output space, we adopt a directional distance approach. We treat a mortality based measure as a “needs indicator”. We derive pure technical, scale and output congestion inefficiency measures and show how they vary across size classes. We show that “reducing mortality” involves sacrificing some good outputs. This is a trade off that holds at the potential output level. Second stage regressions of the inefficiency scores against hospital and rural district level variables, pinpoint critical areas for performance improvement. In particular we show the relative scarcity of nurses is linked to output congestion.     

Boundary treatment effects on molecular dynamics simulations of interface thermal resistance

Molecular Dynamics simulations of heat conduction in liquid Argon confined in Silver nano-channels are performed subject to three different thermal conditions. Particularly, different surface temperatures are imposed on Silver domains using a thermostat in all and limited number of solid layers, resulting in heat flux in the liquid domain. Alternatively, energy is injected and extracted from solid layers to create a NVE liquid Argon system, which corresponds to heat flux specification. Imposition of a constant temperature region in the solid domain results in an unphysical temperature jump, indicating the presence of an artificial thermal resistance induced by the thermostat. Thermal resistance analyses for the components of each case are performed to distinguish the artificial and interface thermal resistance effects. Constant wall temperature simulations are shown to exhibit superposition of the artificial and interface thermal resistance values at the liquid/solid interface, while applying thermostat on wall layers sufficiently away from the liquid/solid interface results in consistent predictions of the interface thermal resistance. Injecting and extracting energy from each solid layer eliminates the artificial resistance. However, the method cannot directly specify a desired temperature difference between the two solid domains.     

Mathematics Anxiety and Preservice Elementary Teachers' Confidence to Teach Mathematics and Science

Sixty‐five preservice elementary teachers' math anxiety levels and confidence levels to teach elementary mathematics and science were measured. The confidence scores of subjects in different math anxiety groups were compared and the relationships between their math anxiety levels and confidence levels to teach mathematics and science were investigated. The results suggest that low math anxious preservice teachers are more confident to teach elementary mathematics and science than are their peers having higher levels of math anxiety. Negative correlations were found between preservice teachers' math anxiety and their confidence scores to teach elementary mathematics (r = ?.638) and between preservice teachers' math anxiety and their confidence scores to teach elementary science (r = ‐.417). Also, personal math and science teaching self‐efficacy scores of participants were found to be correlated at .01 level (r =.549).