8 research outputs found

    Developments in hot-filament metal oxide deposition (HFMOD)

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    Hot-filament metal oxide deposition (HFMOD) is a variant of conventional hot-filament chemical vapor deposition (HFCVD) recently developed in our laboratory and successfully used to obtain high-quality, uniform films of MOx WOx and VOx. The method employs the controlled oxidation of a filament of a transition metal heated to 1000 degrees C or more in a rarefied oxygen atmosphere (typically, of about 1 Pa). Metal oxide vapor formed on the surface of the filament is transported a few centimetres to deposit on a suitable substrate. Key system parameters include the choice of filament material and diameter, the applied current and the partial pressures of oxygen in the chamber. Relatively high film deposition rates, such as 31 nm min(-1) for MoOx, are obtained. The film stoichiometry depends on the exact deposition conditions. MoOx films, for example, present a mixture of MoO2 and MoO3 phases, as revealed by XPS. As determined by Li+ intercalation using an electrochemical cell, these films also show a colouration efficiency of 19.5 cm(2) C-1 at a wavelength of 700 nm. MOx and WOx films are promising in applications involving electrochromism and characteristics of their colouring/bleaching cycles are presented. The chemical composition and structure of VOx films examined using IRRAS (infrared reflection-absorption spectroscopy), RBS (Rutherford backscattering spectrometry) and XPS (X-ray photoelectron spectrometry) are also presented. (c) 2007 Elsevier B.V. All rights reserved

    Infrared spectroscopy investigation of various plasma-deposited polymer films irradiated with 170 keV He+ ions

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    This work illustrates the advantages of using p-polarized radiation at an incidence angle of 70 degrees in contrast to the conventional unpolarized beam at normal (or near-normal) incidence for the infrared spectroscopic study of polycarbosilane, polysilazane and polysiloxane thin films synthesized by plasma enhanced chemical vapor deposition (PECVD) and subsequently irradiated with 170 keV He+ ions at fluences from 1 x 10(14) to 1 x 10(16) cm(-2). Several bands not seen using the conventional mode could be observed in the polarized mode. (c) 2006 Elsevier B.V. All rights reserved

    Comparative study on MoO3 and HxMoO3 nanobelts : structure and electric transport

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    In this study, the suspension of MoO3 nanobelts was first prepared in a hydrothermal way from Mo powders and H2O2 solution, which could be transformed into the suspension of HxMoO3 nanobelts under an acidic condition using N2H4 ·H2O as the reducing agent. Three paper-form samples made from MoO3 and HxMoO3 nanobelts (low or high hydrogen content) were then fabricated via a vacuum filtration method, followed by their structural comparative analysis such as FESEM, XRD, Raman spectra, and XPS, etc. The measurement of electric resistances at room temperature shows that the conductance of HxMoO3 nanobelts is greatly improved because of hydrogen doping. The temperature-dependent resistances of HxMoO3 nanobelts agree with the exponential correlation, supporting that the conducting carriers are the quasi-free electrons released from Mo5+. In addition, the formation process of HxMoO3 nanobelts from MoO3 nanobelts is also discussed

    An international SUrvey on non-iNvaSive tecHniques to assess the mIcrocirculation in patients with RayNaud'€™s phEnomenon (SUNSHINE survey)

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    To canvas opinion concerning the role of non-invasive techniques in the assessment of patients with Raynaud's phenomenon (Rp) in clinical and research settings: four nailfold capillaroscopy methods [videocapillaroscopy (NVC), dermoscopy, stereomicroscopy, digital USB microscopy], four laser Doppler methods (laser Doppler flowmetry, imaging, anemometry/velocimetry, laser speckle contrast analysis), thermographic imaging, and upper limb arterial Doppler ultrasound. Emails with a link to the survey were sent to physicians from the European Scleroderma Trials and Research group (EUSTAR), the EULAR Study Group on Microcirculation in Rheumatic Diseases (SG_MC/RD) and members of the pediatric rheumatology Email board. The main descriptive analysis related to physicians looking after adult patients, with some analysis also of opinions from paediatric rheumatologists. 106 'adult physicians' responded (a response rate of 25.8%), of whom 68.9% were European, and 81.1% practising for more than 10 years. Nineteen paediatricians responded. The most widely available technique was NVC (72.7%). Nailfold capillaroscopy was most frequently performed by the physician him/herself, using different types of equipment relating to availability. Most rheumatologists reported high levels of appropriateness for NVC in both clinical and research settings for global assessment and differential diagnosis of Rp. Other techniques were less used. Of all the different techniques, nailfold capillaroscopy was the one most used in both clinical and research settings by adult physicians, the majority of whom use NVC in their everyday practice. The low proportion of clinicians using other techniques suggests that these are currently mainly research tools, available only in specialist centres

    An international SUrvey on non-iNvaSive tecHniques to assess the mIcrocirculation in patients with RayNaud'\u80\u99s phEnomenon (SUNSHINE survey)

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    To canvas opinion concerning the role of non-invasive techniques in the assessment of patients with Raynaud's phenomenon (Rp) in clinical and research settings: four nailfold capillaroscopy methods [videocapillaroscopy (NVC), dermoscopy, stereomicroscopy, digital USB microscopy], four laser Doppler methods (laser Doppler flowmetry, imaging, anemometry/velocimetry, laser speckle contrast analysis), thermographic imaging, and upper limb arterial Doppler ultrasound. Emails with a link to the survey were sent to physicians from the European Scleroderma Trials and Research group (EUSTAR), the EULAR Study Group on Microcirculation in Rheumatic Diseases (SG_MC/RD) and members of the pediatric rheumatology Email board. The main descriptive analysis related to physicians looking after adult patients, with some analysis also of opinions from paediatric rheumatologists. 106 'adult physicians' responded (a response rate of 25.8%), of whom 68.9% were European, and 81.1% practising for more than 10 years. Nineteen paediatricians responded. The most widely available technique was NVC (72.7%). Nailfold capillaroscopy was most frequently performed by the physician him/herself, using different types of equipment relating to availability. Most rheumatologists reported high levels of appropriateness for NVC in both clinical and research settings for global assessment and differential diagnosis of Rp. Other techniques were less used. Of all the different techniques, nailfold capillaroscopy was the one most used in both clinical and research settings by adult physicians, the majority of whom use NVC in their everyday practice. The low proportion of clinicians using other techniques suggests that these are currently mainly research tools, available only in specialist centres
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