1,168 research outputs found

    Electron-spectroscopic investigation of metal-insulator transition in Sr2Ru1-xTixO4 (x=0.0-0.6)

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    We investigate the nature and origin of the metal-insulator transition in Sr2Ru1-xTixO4 as a function of increasing Ti content (x). Employing detailed core, valence, and conduction band studies with x-ray and ultraviolet photoelectron spectroscopies along with Bremsstrahlung isochromat spectroscopy, it is shown that a hard gap opens up for Ti content greater than equal to 0.2, while compositions with x<0.2 exhibit finite intensity at the Fermi energy. This establishes that the metal-insulator transition in this homovalent substituted series of compounds is driven by Coulomb interaction leading to the formation of a Mott gap, in contrast to transitions driven by disorder effects or band flling.Comment: Accepted for publication in Phys. Rev.

    New Samarium and Neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field

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    Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25 atomic percent of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of zero magnetization axis at low magnetic fields (less than 103 Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with no net magnetization and appreciable conduction electron polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of about 270 K, underscore the importance of these materials for potential applications in spintronics.Comment: 6 page text + 5 figure

    Direct Ionic Liquid Extractant Injection for Volatile Chemical Analysis - A Gas Chromatography Sampling Technique

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    A green sampling approach by direct injection of ionic liquid (IL) solvent containing a variety of analytes using programmable temperature vaporisation (PTV) injection with gas chromatography (GC) is presented. The method was developed using test mixtures of n-alkanes, n-alcohols and polyaromatic compounds, whilst back extraction of isolated compounds from the IL with organic solvent is not required. In the final method, 2 ÎŧL of IL, 1-butyl-3 methylimidazolium bis(trifluoromethylsulfonyl)amide containing analytes, was diluted to different volumes (ranging from 10 to 70%) with solvent then injected into the system. Several PTV injector parameters were investigated to ensure analyte volatilisation and transfer into the GC column. Concentration calibration curves (10–150 Îŧg mL−1 and 10–100 Îŧg mL−1 for n-alkanes and n-alcohols, respectively) were constructed, and showed addition of IL increased the peak area of each analyte, with good precision, and acceptable linearity with correlation coefficient, r2 > 0.93. This method was successfully applied in analysis of a polynuclear aromatic hydrocarbons (PAHs) mixture, with addition of IL in the mixture and suitable operation of the PTV injector. The method was also applied to eucalyptus leaf essential oil compounds as a test sample in a single drop microextraction experiment

    Implementation and delivery of group consultations for young people with diabetes in socioeconomically deprived, ethnically diverse settings

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    BACKGROUND: Young people with diabetes experience poor clinical and psychosocial outcomes, and consider the health service ill-equipped in meeting their needs. Improvements, including alternative consulting approaches, are required to improve care quality and patient engagement. We examined how group-based, outpatient diabetes consultations might be delivered to support young people (16-25 years old) in socio-economically deprived, ethnically diverse settings. METHODS: This multi-method, comparative study recruited a total of 135 young people with diabetes across two implementation and two comparison sites (2017-2019). Informed by a 'researcher-in-residence' approach and complexity theory, we used a combination of methods: (a) 31 qualitative interviews with young people and staff and ethnographic observation in group and individual clinics, (b) quantitative analysis of sociodemographic, clinical, service use, and patient enablement data, and (c) micro-costing analysis. RESULTS: Implementation sites delivered 29 group consultations in total. Overall mean attendance per session was low, but a core group of young people attended repeatedly. They reported feeling better understood and supported, gaining new learning from peers and clinicians, and being better prepared to normalise diabetes self-care. Yet, there were also instances where peer comparison proved difficult to manage. Group consultations challenged deeply embedded ways of thinking about care provision and required staff to work flexibly to achieve local tailoring, sustain continuity, and safely manage complex interdependencies with other care processes. Set-up and delivery were time-consuming and required in-depth clinical and relational knowledge of patients. Facilitation by an experienced youth worker was instrumental. There was indication that economic value could derive from preventing at least one unscheduled consultation annually. CONCLUSIONS: Group consulting can provide added value when tailored to meet local needs rather than following standardised approaches. This study illustrates the importance of adaptive capability and self-organisation when integrating new models of care, with young people as active partners in shaping service provision. TRIAL REGISTRATION: ISRCTN reference 27989430
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