Possibility to realize spin-orbit-induced correlated physics in iridium fluorides

Recent theoretical predictions of "unprecedented proximity" of the electronic ground state of iridium fluorides to the SU(2) symmetric $j_{\mathrm{eff}}=1/2$ limit, relevant for superconductivity in iridates, motivated us to investigate their crystal and electronic structure. To this aim, we performed high-resolution x-ray powder diffraction, Ir L$_3$-edge resonant inelastic x-ray scattering, and quantum chemical calculations on Rb$_2$[IrF$_6$] and other iridium fluorides. Our results are consistent with the Mott insulating scenario predicted by Birol and Haule [Phys. Rev. Lett. 114, 096403 (2015)], but we observe a sizable deviation of the $j_{\mathrm{eff}}=1/2$ state from the SU(2) symmetric limit. Interactions beyond the first coordination shell of iridium are negligible, hence the iridium fluorides do not show any magnetic ordering down to at least 20 K. A larger spin-orbit coupling in iridium fluorides compared to oxides is ascribed to a reduction of the degree of covalency, with consequences on the possibility to realize spin-orbit-induced strongly correlated physics in iridium fluorides

Global occurrence, chemical properties, and ecological impacts of e-wastes (IUPAC technical report)

The waste stream of obsolete electronic equipment grows exponentially, creating a worldwide pollution and resource problem. Electrical and electronic waste (e-waste) comprises a heterogeneous mix of glass, plastics (including flame retardants and other additives), metals (including rare earth elements) and metalloids. The e-waste issue is complex and multi-faceted. In examining the different aspects of e-waste, informal recycling in developing countries has been identified as a primary concern due to widespread illegal shipments, weak environmental as well as health and safety regulations, lack of technology and inadequate waste treatment structure. For example, Nigeria, Ghana, India, Pakistan and China have all been identified as hotspots for the disposal of e-waste. This article presents a critical examination on the chemical nature of e-waste and the resulting environmental impacts on, for example, microbial biodiversity, flora and fauna in e-waste recycling sites around the world. It highlights the different types of risk assessment approaches required when evaluating the ecological impact of e-waste. Additionally, it presents examples of chemistry playing a role in potential solutions. The information presented here will be informative to relevant stakeholders to devise integrated management strategies to tackle this global environmental concern

Victorian Audit of Surgical Mortality is associated with improved clinical outcomes

This study was presented at the Conjoint Medical Education seminar on revalidation held in March 2014 by the RACS in Melbourne.Background: Improved outcomes are desirable results of clinical audit. The aim of this study was to use data from the Victorian Audit of Surgical Mortality (VASM) and the Victorian Admitted Episodes Dataset (VAED) to highlight specific areas of clinical improvement and reduction in mortality over the duration of the audit process. Methods: This study used retrospective, observational data from VASM and VAED. VASM data were reported by participating public and private health services, the Coroner and self-reporting surgeons across Victoria. Aggregated VAED data were supplied by the Victorian Department of Health. Assessment of outcomes was performed using chi-squared trend analysis over successive annual audit periods. Because initial collection of data was incomplete in the recruitment phase, statistical analysis was confined to the last 3-year period, 2010–2013. Results: A 20% reduction in surgical mortality over the past 5 years has been identified from the VAED data. Progressive increase in both surgeon and hospital participation, significant reduction in both errors in management as perceived by assessors and increased direct consultant involvement in cases returned to theatre have been documented. Conclusions: The benefits of VASM are reflected in the association with a reduction of mortality and adverse clinical outcomes, which have clinical and financial benefits. It is a purely educational exercise and continued participation in this audit will ensure the highest standards of surgical care in Australia. This also highlights the valuable collaboration between the Victorian Department of Health and the RACS.C. Barry Beiles, Claudia Retegan and Guy J. Madder

Clinical management issues vary by specialty in the Victorian Audit of Surgical Mortality: a retrospective observational study

OBJECTIVE: Clinical management issues are contributory factors to mortality. The aim of this study was to use data from the Victorian Audit of Surgical Mortality (VASM), an educational peer-review process for surgeons, to discover differences in the incidence of these issues between surgical specialties in order to focus attention to areas of care that might be improved. DESIGN: This study used retrospectively analysed observational data from VASM. Clinical management issues between eight specialties were assessed using χ(2) analysis. DATA SOURCES: VASM data were reported by participating public and private health services, the Coroner and self-reporting surgeons across Victoria. RESULTS: A total of 2946 specific clinical issues as deficiencies of care were reported. 15% of cases had significant issues of care. The most common clinical management issue was the delay in delivery of treatment. Other clinical issues included the quality of communication and documentation, preoperative and postoperative care, adverse events and protocol issues. There were significant differences in issues between specialties. CONCLUSIONS: The clinical management issues presented across surgical specialties were similar; however, five issues of clinical care differed significantly in frequency across surgical specialties. The three main issues varying among specialties were complications after operation, communication and postoperative care. Addressing these clinical management issues via the peer-review process may impact positively on patient care

The behaviour of organic solvents containing C5-BTBP and CyMe4-BTBP at low irradiation doses

Low doses of gamma radiation were given to four different solvents containing C5-BTBP and CyMe4-BTBP, each molecule dissolved both in cyclohexanone and hexanol. Four corresponding solvents were kept unirradiated and used as references for the extraction experiments. Multiple samples were taken from both the irradiated solutions and the reference solutions at certain time intervals. The samples were used in extraction experiments with the radionuclides Am-241 and Eu-152. The protection against radiolysis of the extracting molecules by the diluent used for dissolution without adding a scavenger molecule was checked. The interplay between the diluent and the side group of the extracting molecule for protection against radiolysis was also studied by keeping the same type of core molecule for binding to the metal ions and varying the diluent and side group. The results were unexpected. The presence of a cyclic molecule as both a side group or diluent seems to keep the extraction of europium almost unaffected by radiolysis, while americium behaves differently from solvent to solvent. The diluent alone does not protect the extracting molecule. In some of the studied systems there is a distinct change in the extraction behaviour of Am between the irradiated and reference solutions, an effect that is however only present at the beginning of the experimental series. At later times the difference in distribution ratios between the irradiated and reference solution is constant. This phenomenon is found only when the side group and diluent are structurally dissimilar

Influence of dose rate on the radiolytic stability of a BTBP solvent for actinide(III)/lanthanide(III) separation

The recently developed ligand MF2-BTBP dissolved in cyclohexanone is a promising solvent for the group separation of trivalent actinides(Ill) from the lanthanides(Ill). Its high stability against nitric acid has been demonstrated recently. Since the solvent is also exposed to a continuously high radiation level in the counter current process, the radiolytic stability of the solvent was examined in this study. Irradiation experiments were carried out up to an absorbed dose of 100 kGy and the effect of the dose rate was investigated. The extraction behaviour for An(III)/Ln(III) separation was studied after radiolysis for evaluation. It was found that during high dose rate irradiation the extraction efficiency for both Am(III) and Eu(III) decreased significantly with increasing absorbed dose, whereas during the low dose rate irradiation the extraction efficiencies remained more or less at the same level

Influence of dose rate on the radiolytic stability of a BTBP solvent for actinide(III)/lanthanide(III) separation

The recently developed ligand MF2-BTBP dissolved in cyclohexanone is a promising solvent for the group separation of trivalent actinides(Ill) from the lanthanides(Ill). Its high stability against nitric acid has been demonstrated recently. Since the solvent is also exposed to a continuously high radiation level in the counter current process, the radiolytic stability of the solvent was examined in this study. Irradiation experiments were carried out up to an absorbed dose of 100 kGy and the effect of the dose rate was investigated. The extraction behaviour for An(III)/Ln(III) separation was studied after radiolysis for evaluation. It was found that during high dose rate irradiation the extraction efficiency for both Am(III) and Eu(III) decreased significantly with increasing absorbed dose, whereas during the low dose rate irradiation the extraction efficiencies remained more or less at the same level