Structural stability and local electronic properties of some EC synthesized magnetite nanopowders

Structural and electronic properties, oxidation and aging effect of electrochemically (EC) synthesized magnetite nanopowders (NPs) are studied by means of X–ray diffraction (XRD), X–ray absorption fine structure (XAFS) and X–ray magnetic circular dichroism (XMCD). The obtained results enabled to get a direct insight into the structure and electronic properties of Fe immediate surrounding and to elucidate the influence of preparation conditions on stoichiometry of NPs and their stability in ambient conditions. All investigated NPs are produced as non–stoichiometric Fe$_{3−δ}$O$_4$ oxide phases, with the lattice constant and the Fe$^{2+}$/Fe$^{3+}$ ratio both in–between the values for bulk maghemite and magnetite. NPs synthesized under smaller current density (J = 200 mA/dm$^2$) are more magnetite–alike, whereas larger current density (J = 1000 mA/dm$^2$) has led to formation of NPs closer to maghemite. Oxidation of magnetite–like NPs is slower, although in the course of time particles agglomerate and oxide penetrates into the core. Maghemite–like NPs oxidize much faster and the oxide layer which is confined close to the particles' surface protects the core from further oxidation. In all NPs the fist coordination around Fe is pretty stable against both temperature and oxidation process. The temperature change from 293 K to 20 K considerably affects the second coordination around Fe, which is most likely a consequence of the Verwey transition present in all investigated samples

Is WO3 catalyst for hydrogen desorption?

Magnesium hydride, as hydrogen storage material, meets the requirements such as high gravimetric hydrogen capacity (7,6 wt%), low cost and weight, abundance and H2 absorption/desorption cycling possibility. Given that the oxide additives show the good impact on desorption properties, mechanical milling of MgH2 with addition of 5, 10 and 15% wt. WO3 was performed. The microstructure and morphology of composites were analysed by XRD, PSD and SEM and correlated to hydrogen desorption properties which have been investigated by DSC. The results have shown that WO3 has a positive effect on the desorption kinetics as well as on the change of the desorption mechanism

Is WO3 catalyst for hydrogen desorption?

Magnesium hydride, as hydrogen storage material, meets the requirements such as high gravimetric hydrogen capacity (7,6 wt%), low cost and weight, abundance and H2 absorption/desorption cycling possibility. Given that the oxide additives show the good impact on desorption properties, mechanical milling of MgH2 with addition of 5, 10 and 15% wt. WO3 was performed. The microstructure and morphology of composites were analysed by XRD, PSD and SEM and correlated to hydrogen desorption properties which have been investigated by DSC. The results have shown that WO3 has a positive effect on the desorption kinetics as well as on the change of the desorption mechanism

Survey of electronic properties and local structures around Fe in selected multinary chalcogenides

Paper presents detailed studies of local and electronic structure around Fe in Cd0.97Fe0.03Te, Cd0.98Fe0.02Te0.97Se0.03 and Cd0.99Fe0.01Te0.91S0.09 multinary chalcogenides by means of X ray absorption fine structure XAFS , X ray magnetic circular dichroism XMCD and electron paramagnetic resonance EPR measurements. In addition, electronic consequences of Fe incorporation into CdTe semiconductor host were studied by means of first principles calculations. In order to improve accuracy of the calculated total energies, the band gaps and the band edge positions, special attention is paid to the treatment of exchange correlation interaction and the description of highly localized Fe 3d states. Also, the Bader theory of the topological properties of the electron charge density is used to access details of the nature, strength and distribution of the next nearest neighbour bonds. Local and electronic structure around Fe in Cd0.97Fe0.03Te and Cd0.98Fe0.02Te0.97Se0.03 systems have been found to exhibit similar characteristics, since the first coordination sphere around Fe comprises four Te atoms located at approximately the same distance. In Cd0.99Fe0.01Te0.91S0.09 system, however, local bimodal distribution of distances has been revealed, with one Fe Te bond replaced with much shorter Fe S bond, resulting in much stronger crystal field. Along with the crystal field effect, the spin orbit interaction has proven to play decisive role in determining the nature of Fe doped CdTe systems. While the systems with higher Fe concentrations 25 at. are intrinsic insulators, in systems with only 3.125 at. Fe one spin channel contributes to the density of states at the Fermi level, which makes them suitable for spin selective electronic transport application

Is WO3 catalyst for hydrogen desorption?

Magnesium hydride, as hydrogen storage material, meets the requirements such as high gravimetric hydrogen capacity (7,6 wt%), low cost and weight, abundance and H2 absorption/desorption cycling possibility. Given that the oxide additives show the good impact on desorption properties, mechanical milling of MgH2 with addition of 5, 10 and 15% wt. WO3 was performed. The microstructure and morphology of composites were analysed by XRD, PSD and SEM and correlated to hydrogen desorption properties which have been investigated by DSC. The results have shown that WO3 has a positive effect on the desorption kinetics as well as on the change of the desorption mechanism

Electrochemical sensors based on pyrophyllite

V Conference of The Serbian Society for Ceramic Materials, 5CSCS-2019, June 11-13, 2019, Belgrade, Serbi

cExternal beam radiation results in minimal changes in post void residual urine volumes during the treatment of clinically localized prostate cancer

<p>Abstract</p> <p>Background</p> <p>To evaluate the impact of external beam radiation therapy (XRT) on weekly ultrasound determined post-void residual (PVR) urine volumes in patients with prostate cancer.</p> <p>Methods</p> <p>125 patients received XRT for clinically localized prostate cancer. XRT was delivered to the prostate only (n = 66) or if the risk of lymph node involvement was greater than 10% to the whole pelvis followed by a prostate boost (n = 59). All patients were irradiated in the prone position in a custom hip-fix mobilization device with an empty bladder and rectum. PVR was obtained at baseline and weekly. Multiple clinical and treatment parameters were evaluated as predictors for weekly PVR changes.</p> <p>Results</p> <p>The mean patient age was 73.9 years with a mean pre-treatment prostate volume of 53.3 cc, a mean IPSS of 11.3 and a mean baseline PVR of 57.6 cc. During treatment, PVR decreased from baseline in both cohorts with the absolute difference within the limits of accuracy of the bladder scanner. Alpha-blockers did not predict for a lower PVR during treatment. There was no significant difference in mean PVR urine volumes or differences from baseline in either the prostate only or pelvic radiation groups (p = 0.664 and p = 0.458, respectively). Patients with a larger baseline PVR (>40 cc) had a greater reduction in PVR, although the greatest reduction was seen between weeks one and three. Patients with a small PVR (<40 cc) had no demonstrable change throughout treatment.</p> <p>Conclusion</p> <p>Prostate XRT results in clinically insignificant changes in weekly PVR volumes, suggesting that radiation induced bladder irritation does not substantially influence bladder residual urine volumes.</p

Public health in community pharmacy: a systematic review of pharmacist and consumer views

BACKGROUND The increasing involvement of pharmacists in public health will require changes in the behaviour of both pharmacists and the general public. A great deal of research has shown that attitudes and beliefs are important determinants of behaviour. This review aims to examine the beliefs and attitudes of pharmacists and consumers towards pharmaceutical public health in order to inform how best to support and improve this service. METHODS Five electronic databases were searched for articles published in English between 2001 and 2010. Titles and abstracts were screened by one researcher according to the inclusion criteria. Papers were included if they assessed pharmacy staff or consumer attitudes towards pharmaceutical public health. Full papers identified for inclusion were assessed by a second researcher and data were extracted by one researcher. RESULTS From the 5628 papers identified, 63 studies in 67 papers were included. Pharmacy staff: Most pharmacists viewed public health services as important and part of their role but secondary to medicine related roles. Pharmacists' confidence in providing public health services was on the whole average to low. Time was consistently identified as a barrier to providing public health services. Lack of an adequate counselling space, lack of demand and expectation of a negative reaction from customers were also reported by some pharmacists as barriers. A need for further training was identified in relation to a number of public health services. Consumers: Most pharmacy users had never been offered public health services by their pharmacist and did not expect to be offered. Consumers viewed pharmacists as appropriate providers of public health advice but had mixed views on the pharmacists' ability to do this. Satisfaction was found to be high in those that had experienced pharmaceutical public health. CONCLUSIONS There has been little change in customer and pharmacist attitudes since reviews conducted nearly 10 years previously. In order to improve the public health services provided in community pharmacy, training must aim to increase pharmacists' confidence in providing these services. Confident, well trained pharmacists should be able to offer public health service more proactively which is likely to have a positive impact on customer attitudes and health

The simple one-step solvothermal synthesis of nanostructurated VO2(B)

VO2(B) has been successfully synthesized by simple, facile and environmental friendly one-step solvothermal method using V2O5 and ethanol as a starting agent. Obtained micrometer-sized powder was composed from mutually welded nanosized rod-like, flat and snowflake structures. VO2(B) powder was tested for possible application as anode material for aqueous lithium ion batteries. Lithium intercalation/deintercalation reaction has been carried out by cyclic voltammetry in a saturated aqueous solution of LiNO3. At scan rate of 10 mV s(-1) very stable cyclic performance of such obtained VO2 was established with discharge capacity around 184 mAh g(-1). (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved