Luminescence Properties of Sm2+-Activated Barium Chloroborates

The luminescence properties of Sm2+-activated stoichiometric and non-stoichiometric Ba2B5O9Cl were investigated from 16 to 450 K. In stoichiometric Ba2B5O9Cl, the emission spectra of Sm2+ are composed of 4f6-4f6 transitions over the 16-450K temperature range studied. Luminescence was observed from Sm2+ in four inequivalent cationic sites at 16K andtwo inequivalent sites at room temperature. In the non-stoichiometric compound, the emission is characterized by 4f6-4f6 transitions at low temperature and 4f->5d1-4f6 transitions at high temperature. The Sm2+ doped into the Ca2+ and Sr 2+ analogues in the M2B5O9Cl series shows the broadband 4f->5d1-4f6 luminescence in both the stoichiometric and non-stoichiometric compounds due to the increased ligand field caused by the smaller ionic radii of the metal ions

Glyphosate in waters and soils from genetically modified canola cultivation in Parkes, NSW, Australia

Investigations were conducted of farmland from the Parkes region of New South Wales, Australia, cultivated with genetically modified canola, involving the determination of glyphosate (N-(phosphonomethyl)glycine) concentrations in water and soils, and its sorption. The soils are classified as loam under the USDA system (clay 13.8-15.8%, silt 39-43%, sand 41.2-47.2%). Firstly, a low-cost fluorometric method was developed for the analysis of glyphosate in waters and soils, calibrated against analytical standards and spectrophotometric and enzyme-linked immunosorbent assay (ELISA) methods. Soil and water samples were then collected using the NEPM sampling protocol into glass containers, chilled and analysed within two weeks. The samples were collected in multiple episodes, taking account of glyphosate and pesticide crop applications. The soil and water physical and chemical properties were characterised, and glyphosate levels were determined. Field concentrations of glyphosate ranged between 0.01 - 0.067 mg/L in water and 0.10 - 0.575 mg/kg in soil. The aqueous levels lie below Australian and international drinking water guidelines, but reach a Canadian freshwater guideline. Glyphosate levels varied with time of application and rainfall events. Glyphosate sorption isotherms were also constructed by batch tests on several soils, and were fitted with Freundlich and Langmuir isotherms. Desorption tests indicated 25% to 58% of soil glyphosate is extractable by 0.1M KH2PO4

Memory of low magnetic fields in persistent spectral hole-burning of the 2 E← 4 A 2 spin-flip transition in NaMgAl(oxalate) 3 · 9H 2 O:Cr(III)

The effects of weak magnetic fields (<16 mT) in persistent non-photochemical spectral hole-burning of the R1-line (2E → 4A2 transition) in NaMgAl(oxalate)3 · 9H2O : Cr(III) are reported. The observed hole patterns can be quantitatively rationalized wi

Massive enhancement of persistent spectral hole-burning in the R-lines of NaMgAl(oxalate) 3 · 9H 2 O:Cr(III) by partial deuteration

Partial deuteration of NaMgAl(oxalate)3· 9H2O:Cr(III) (0.5%) increases the quantum efficiency for persistent spectral hole-burning in the R1-line by three orders of magnitude. A 50% deuterated crystal shows an impressive initial hole-burning efficiency

Zeeman Effects in Transient Spectral Hole-Burning of the R 1 Line of NaMgAl(Oxalate) 3 ·9H 2 O/Cr(III) in Low Magnetic Fields

Transient spectral hole-burning experiments, using diode lasers, in minute external magnetic fields of <16 mT are reported for the lower-energy 2E ← 4A2 spin-flip transition of NaMgAl(oxalate)3·9H2O/Cr(III). Ground- and excited-state g factors can be

Revisiting the crystal structure and thermal properties of NaMgAl(oxalate) sub>3 •9H 2 O/Cr(III): an extraordinary spectral hole-burning material

We have reinvestigated the crystal structure and thermal properties of NaMgAl(oxalate)3•9H2O. In the thermal gravimetric analysis the steps of dehydration and decomposition/oxidation yield a mass change that is commensurate with 9 water molecules of hy