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Sacrificial coatings, such as Zn and Cd, are used to protect steel against corrosion. During the electrodeposition of metals, hydrogen is evolved due to electrolysis. The evolved hydrogen may diffuse outward and become trapped in the substrate/coating interface or migrate inward into the steel lattice causing delayed embrittlement when the component is subjected to stress. This study reports two principal variables for Zn, Zn-Ni, and Cd coatings: (i) the quantity of hydrogen absorbed by the coating and substrate by vacuum thermal desorption and (ii) the permeability of the coating material to hydrogen by electrochemical permeation. The findings were analyzed in correlation with the microstructural characteristics of both the coating material and the coating/substrate interface. With Zn-Ni, both coating process and coating material combined to significantly reduce the risk of internal hydrogen embrittlement by (i) introducing the least amount of hydrogen during the electrodeposition process and (ii) by the ease with which hydrogen can be extracted by baking due to the presence of cracks in the coating. [ABSTRACT FROM AUTHOR]

An electrochemical method of fabrication of (NiCoCrAlY)/MgO/yttria-stabilized zirconia (YSZ) multilayered coating was proposed. This multilayered coat is expected to work as a thermal barrier coating for nickel superalloy substrates. The (NiCoCrAlY) layer was deposited using the electrophoretic deposition technique, the MgO layer was deposited by the electrolytic deposition technique and the YSZ layer was electrophoretically deposited. The process of depositing (NiCoCrAlY) alloy particles revealed that the electrophoretic technique can be used for particles with submicron dimensions. The MgO intermediate layer was introduced to accommodate the difference in thermal expansion coefficient between the YSZ ceramic and the NiCoCrAlY metal layers. [ABSTRACT FROM AUTHOR]

Considering the poor long-term success of current dietary and pharmacological interventions, we aimed to evaluate the potential effect of sodium tungstate in the treatment of grade I and II obesity ( identifier: NCT00555074). Prospective, randomized, placebo-controlled, double-blind, proof-of-concept study was carried out. Following a 2-week lead-in period, 30 obese (body mass index, BMI 30.0-39.9 kg/m), non-diabetic subjects were randomized to receive either sodium tungstate (100 mg bid) or placebo for 6 weeks. The primary study endpoint was the absolute change in body weight relative to the time of randomization. Treatment with sodium tungstate [−0.135 ± 0.268 kg (95% CI −0.686 to +0.416 kg)] was not associated with a significant weight loss compared to placebo [−0.063 ± 0.277 kg (95% CI −0.632 to +0.507 kg)] (p = 0.854). Likewise, treatment with sodium tungstate was not associated with significant changes in fat mass (DEXA), resting energy expenditure (indirect calorimetry) or caloric consumption (3-day food records). Our data do not support sodium tungstate as a pharmacological agent in the treatment of human obesity. [ABSTRACT FROM AUTHOR]

Abstract: For semi solid metal (SSM) slurries, in addition to the morphology, size, distribution and percentage of the solid phase particles, the microstructure of individual solid particles is another important parameter to be considered. This is particularly an issue when SSM billets are prepared by continuous stirring of the melt to temperatures below liquidus, as in the case of electromagnetic stirring of Al–Si alloys. Microstructural evolution of the electromagnetically stirred Al–Si alloy is investigated by means of optical and electron microscopy. Electron backscatter diffraction (EBSD) analysis of the stirred and unstirred cast billets has shown stirring to generate local misorientation within individual solid particles. This is an indication of growing dendrites undergoing plastic deformation during the course of SSM slurry preparation. The formation of dislocations and their subsequent rearrangement into subgrain boundaries has been shown by EBSD analysis and TEM studies of thin foil specimens respectively. [Copyright &y& Elsevier]

Results of an international intercomparison study (CCQM-P86) to assess the analytical capabilities of national metrology institutes (NMIs) and selected expert laboratories worldwide to accurately quantitate the mass fraction of selenomethionine (SeMet) and total Se in pharmaceutical tablets of selenised-yeast supplements (produced by Pharma Nord, Denmark) are presented. The study, jointly coordinated by LGC Ltd., UK, and the Institute for National Measurement Standards, National Research Council of Canada (NRCC), was conducted under the auspices of the Comité Consultatif pour la Quantité de Matière (CCQM) Inorganic Analysis Working Group and involved 15 laboratories (from 12 countries), of which ten were NMIs. Apart from a protocol for determination of moisture content and the provision of the certified reference material (CRM) SELM-1 to be used as the quality control sample, no sample preparation/extraction method was prescribed. A variety of approaches was thus used, including single-step and multiple-step enzymatic hydrolysis, enzymatic probe sonication and hydrolysis with methanesulfonic acid for SeMet, as well as microwave-assisted acid digestion and enzymatic probe sonication for total Se. For total Se, detection techniques included inductively coupled plasma (ICP) mass spectrometry (MS) with external calibration, standard additions or isotope dilution MS (IDMS), inductively coupled plasma optical emission spectrometry , flame atomic absorption spectrometry and instrumental neutron activation analysis. For determination of SeMet in the tablets, five NMIs and three academic/institute laboratories (of a total of five) relied upon measurements using IDMS. For species-specific IDMS measurements, an isotopically enriched standard of SeMet (76Se-enriched SeMet) was made available. A novel aspect of this study relies on the approach used to distinguish any errors which arise during analysis of a SeMet calibration solution from those which occur during analysis of the matrix. To help those participants undertaking SeMet analysis to do this, a blind sample in the form of a standard solution of natural abundance SeMet in 0.1 M HCl (with an expected value of 956 mg kg−1 SeMet) was provided. Both high-performance liquid chromatography (HPLC)–ICP-MS or gas chromatography (GC)–ICP-MS and GC-MS techniques were used for quantitation of SeMet. Several advances in analytical methods for determination of SeMet were identified, including the combined use of double IDMS with HPLC-ICP-MS following extraction with methanesulfonic acid and simplified two-step enzymatic hydrolysis with protease/lipase/driselase followed by HPLC-ICP-IDMS, both using a species-specific IDMS approach. Overall, satisfactory agreement amongst participants was achieved; results averaged 337.6 mg kg−1 ( n = 13, with a standard deviation of 9.7 mg kg−1) and 561.5 mg kg−1( n = 11, with a standard deviation of 44.3 mg kg−1) with median values of 337.6 and 575.0 mg kg−1 for total Se and SeMet, respectively. Recovery of SeMet from SELM-1 averaged 95.0% ( n = 9). The ability of NMIs and expert laboratories worldwide to deliver accurate results for total Se and SeMet in such materials (selensied-yeast tablets containing approximately 300 mg kg−1 Se) with 10% expanded uncertainty was demonstrated. The problems addressed in achieving accurate quantitation of SeMet in this product are representative of those encountered with a wide range of organometallic species in a number of common matrices. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]