A Critical Look at Strings

Following the invitation of the editors of Foundations of Physics, I give here a personal assessment of string theory, from the point of view of an outsider, and I compare it with the theory, methods, and expectations of my own field.     

A Series of Iron(II)-NHC Sensitizers with Remarkable Power Conversion Efficiency in Photoelectrochemical Cells**

A series of six new Fe(II)NHC-carboxylic sensitizers with their ancillary ligand decorated with functions of varied electronic properties have been designed with the aim to increase the metal-to- surface charge separation and light harvesting in iron-based dye-sensitized solar cells (DSSCs). ARM130 scored the highest efficiency ever reported for an iron-sensitized solar cell (1.83 %) using Mg²⁺ and NBu₄I-based electrolyte and a thick 20 μm TiO₂ anode. Computational modelling, transient absorption spectroscopy and electrochemical impedance spectroscopy (EIS) revealed that the electronic properties induced by the dimethoxyphenyl-substituted NHC ligand of ARM130 led to the best combination of electron injection yield and spectral sensitivity breadth.     

Synthesis and Characterization of 2d Ferromagnetic (RNH3)2CrX4 Containing Mixed-Halides,R = CnH2n+1, X = Br,C1

The bis(benzylammonium)tetrahalogenochromate(II), (C₆H₅CH₂NH₃)₂CrBr₃. ₃Cl₀. 7, has been synthesized and characterized. The crystal structure is related to that of K₂NiF₄. The compound is ferromagnetic and the Curie temperature T_C (T_C= 49 K) has been measured by a mutual inductance technique. The susceptibility increases sharply at T_C and then shows a drop-off below T_C, typical of a single-domain powder sample. The compound is found to behave as a typical 2D easy plane ferromagnet.     

Temporal evolution of DMS and DMSP in Antarctic Coastal Sea water

The temporal evolution of concentrations of dimethylsulphide (DMS), its precursor dimethylsulphoniopropionate (DMSP) and chlorophyll a is surveyed weekly in the water column and in a landfast ice core at a coastal station of Gerlache Inlet (Terra Nova Bay, Antarctica) from 27 November 2000 to 14 February 2001. The DMS and DMSP profile concentrations in the water column are similar and show a clear temporal trend, with minimum values (<0.7?nM) at all depths occurring on 27 November 2000 and maximum values (4.8 × 10²?nM for DMS and 1.8 × 10²?nM for DMSP) in surface water on 27 December 2000 for DMS and on 19 December 2000 for DMSP. When the sea-ice cover is present, the temporal evolution of DMSP closely follows that of chlorophyll a in the water column, supporting the idea that DMSP, and therefore DMS, has a phytoplanktonic origin. However, when the ice cover breaks up during the late austral summer, a second phytoplankton bloom occurs, while the DMSP concentration in the sea-water column remains very low. In the ice core, the results show higher concentrations of DMSP than those of the underlying sea water, highlighting the important role of sea ice in the sulphur cycle of the Antarctic ecosystem.     

Synthesis of (±)-10H-Phenothiazine-10-propanoyl-1′-myo-inositol

The synthesis of (±)10H-phenothiazine-10-propanoyl-1′-myo-inositol was accomplished in order to test it as inhibitor of phosphatidylinositol specfic phospholipase C (PI-PLC).     

Pb2+ Defects in perovskite-like KMgF3 crystals

Abstract

The physical properties of Pb²⁺ impurities in the perovskite-like lattice of KMgF₃ are very similar to those of (ns)² ions in alkali halides. The impurity inhomogeneous distribution leads to high dopant levels in the bottom region of the crystals, with a segregation coefficient equal to 0. 020. The optical features of the 336 nm emission support its attribution to luminescence of Pb²⁺ ions from the relaxed excited B state.     

A fast-neutron coincidence collar using liquid scintillators for fresh fuel verification

Journal of Radioanalytical and Nuclear Chemistry - The IAEA has developed a liquid scintillator-based system for the non-destructive assay of 235U in fresh fuel assemblies. The fast neutron...