Conversion
and alloying type negative electrodes attracted huge
attention in the present research on lithium/sodium-ion batteries
(LIBs/SIBs) due to the high capacity delivered. Among these, SnO
2
is investigated intensively in LIBs due to high cyclability,
low reaction potential, cost-effectiveness, and environmental friendliness.
Most of the LIB electrodes are explored in SIBs too due to expected
similar electrochemical performance. Though several LIB negative electrode
materials successfully worked in SIBs, bare SnO
2
shows
very poor electrochemical performance in SIB. The reason for this
difference is investigated here through combined
in operando
and
ex situ
X-ray absorption spectroscopy (XAS).
For this, the electrodes of SnO
2
(space group
P
4
2
/
mnm
synthesized via one-pot hydrothermal
method) were cycled in Na-ion and Li-ion half-cells. The Na/SnO
2
half-cell delivered a much lower discharge capacity than
the Li/SnO
2
half-cell. In addition, higher irreversibility
was observed for Na/SnO
2
half-cell during electrochemical
investigations compared to that for Li/SnO
2
half-cell.
In operando
XAS investigations on the Na/SnO
2
half-cell confirms incomplete conversion and alloying reactions
in the Na/SnO
2
half-cell, resulting in poor electrochemical
performance. The difference in the lithiation and sodiation mechanisms
of SnO
2
is discussed in detail.
BackgroundTo evaluate the efficacy, safety, pain perception and health-related quality of life (QoL) of percutaneous ethanol injection treatment (PEIT) as an alternative to thyroid surgery in symptomatic thyroid cysts.MethodsThirty consecutive patients (46 ± 10 years; 82 % women) with symptomatic benign thyroid cysts relapsed after drainage were included. In all cases, cytology prior to treatment, maximum cyst diameter and volume were determined. PEIT was conducted using the established procedure, and the volume of fluid removed and pain perceived by the patient were assessed. In each procedure, the volume of alcohol instilled was <2 ml. After follow-up, final cyst diameter and volume were determined and the persistence of symptoms and QoL were assessed by a questionnaire (SF-36).ResultsMean symptom duration was 10 ± 20 months. A single session of PEIT was required to complete the procedure in 45 % of patients, two in 31 % and three in 13 %. Mean initial maximum cyst diameter was 3.5 ± 1.0 cm and mean extracted liquid volume 61 ± 36 ml. During PEIT, 39 % of patients experienced virtually no pain, 43 % mild pain and 17 % moderate pain. No complications of PEIT were observed. After 12.1 ± 1.4 months of follow-up, cysts were reduced more than 70 % in volume in 86.3 % of patients, more than 80 % in 61.9 % and more than 90 % in 42 %. On the health-related QoL SF-36 questionnaire, patient scores 6 months post-PEIT did not differ significantly from those of the healthy Spanish population. With respect to cosmetic complaints or local symptoms of compression, PEIT-treated patients presented an initial score of 22 ± 8 and 13 ± 5 after treatment (p < 0.05).ConclusionsIn our experience, percutaneous ethanol injection has prove to be an effective, safe and well-tolerated first-line treatment of symptomatic thyroid cysts.
Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr.For further information see http://journals.iucr.org/services/authorrights.html Synchrotron radiation research is rapidly expanding with many new sources of radiation being created globally. Synchrotron radiation plays a leading role in pure science and in emerging technologies. The Journal of Synchrotron Radiation provides comprehensive coverage of the entire field of synchrotron radiation research including instrumentation, theory, computing and scientific applications in areas such as biology, nanoscience and materials science. Rapid publication ensures an up-to-date information resource for scientists and engineers in the field.Crystallography Journals Online is available from journals.iucr.org J. Synchrotron Rad. (2010 The mobility, bioavailability and toxicity of mercury in the environment strongly depend on the chemical species in which it is present in soil, sediments, water or air. In mining districts, differences in mobility and bioavailability of mercury mainly arise from the different type of mineralization and ore processing. In this work, synchrotron-based X-ray absorption near-edge spectroscopy (XANES) has been taken advantage of to study the speciation of mercury in geological samples from three of the largest European mercury mining districts: Almadé n (Spain), Idria (Slovenia) and Asturias (Spain). XANES has been complemented with a single extraction protocol for the determination of Hg mobility. Ore, calcines, dump material, soil, sediment and suspended particles from the three sites have been considered in the study. In the three sites, rather insoluble sulfide compounds (cinnabar and metacinnabar) were found to predominate. Minor amounts of more soluble mercury compounds (chlorides and sulfates) were also identified in some samples. Single extraction procedures have put forward a strong dependence of the mobility with the concentration of chlorides and sulfates. Differences in efficiency of roasting furnaces from the three sites have been found.
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