2,025 research outputs found

    Systematic approach to the growth of high-quality single crystals of Sr3Ru2O7

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    We describe a simple procedure for optimising the growth condition for high-quality single crystals of the strontium ruthenate perovskites using an image furnace. The procedure involves carefully measuring the mass lost during crystal growth in order to predict the optimal initial atomic ratio. Using this approach we have succeeded in growing crystals of Sr3Ru 2O7 with a residual resistivity as low as 0.25 ΌΩ cm. The procedure we describe here is expected to be useful for other systems when a standard travelling-solvent floating-zone method cannot be used because of high volatility of a constituent material. © 2004 Elsevier B.V. All rights reserved

    The influence of image interactivity upon user engagement when using mobile touch screens

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    Touch screens are a key component of consumer mobile devices such as smartphones and tablets, as well as an increasingly common self-service component of information retrieval on fixed screens and mobile devices in-store. The ubiquity of touch screens in daily life increases consumer accessibility and extended use for shopping, whilst software innovations have increased the functionality of touch screens, for example the extent to which images respond to fingertip control. This study examines how users engage with interactive visual rotation and tactile simulation features while browsing fashion clothing products on touch screen devices and thus contributes to retail touch screen research that previously focused on in-store kiosks and window displays. Findings show that three dimensions of user engagement (endurability, novelty and felt involvement) are positively influenced by both forms of manipulation. In order to examine the extent to which touch screen user engagement varies with individual preferences for an in-store experience, the paper also examines whether user engagement outcomes are mediated by an individual's need for physical touch. Findings indicate that the need for touch does not explain the variance between individuals. We conclude that touch screen technology complements the physical retail environment

    Hall coefficient anomaly in the low-temperature high-field phase of Sr3Ru2O7

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    We report a study of the Hall effect of high-purity Sr3Ru2O7 single crystals. We establish an empirical correlation between the onset of its unusual low-temperature, high-field phase and a pronounced dip in the fielddependent Hall coefficient. Unlike the order parameter obtained from measurements of anisotropic resistivity, which is affected by the formation of domains, the Hall effect feature seems to reflect the nature of the ordering within a single domain. We checked for violations of the Onsager relations for the off-diagonal components of the resistivity tensor but do not detect any. We compare our observations to those on materials that have long-wavelength spin structures, and discuss them in relation to a growing body of theoretical work on the nature of the low-temperature phase in Sr3Ru2O7

    z+: Neutron cross section separation from wide-angle uniaxial polarization analysis from wide-angle uniaxial polarization analysis

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    We introduce a simple method to extract the nuclear coherent and isotope incoherent, spin incoherent, and magnetic neutron scattering cross section components from powder scattering data measured using a single neutron beam polarization direction and a position-sensitive detector with large out-of-plane coverage. The method draws inspiration from polarized small-angle neutron scattering and contrasts with conventional so-called “ xyz” polarization analysis on wide-angle instruments, which requires measurements with three orthogonal polarization directions. The viability of the method is demonstrated on both simulated and experimental data for the classical “spin ice” system Ho2Ti2O7, the latter from the linear energy transfer direct geometry spectrometer at the International Science Information Service facility. The cross section components can be reproduced with good fidelity by either fitting the out-of-plane angle dependence around a Debye–Scherrer cone or grouping the data by angle and performing a matrix inversion. The limitations of the method and its practical uses are discussed

    The Sister-Chromatid Exchange Assay in Human Cells

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    The semiconservative nature of DNA replication allows the differential labeling of sister chromatids that isthe fundamental requirement to perform the sister-chromatid exchange (SCE) assay. SCE assay is apowerful technique to visually detect the physical exchange of DNA between sister chromatids. SCEscould result as a consequence of DNA damage repair by homologous recombination (HR) during DNAreplication. Here, we provide the detailed protocol to perform the SCE assay in cultured human cells. Cellsare exposed to the thymidine analog 5-bromo-20-deoxyuridine (BrdU) during two cell cycles, resulting inthe two sister chromatids having differential incorporation of the analog. After metaphase spreads prepara-tion and further processing, SCEs are nicely visualized under the microscope

    Suppression of field-induced spin density wave order in Sr_{3}Ru_{2}O_{7} with pressure

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    Measuring the resistivity of high-purity single crystals of Sr_{3}Ru_{2}O_{7} under pressure, we find strong evidence that the field-induced spin density wave phase at the H ∄ c metamagnetic transition is suppressed at a surprisingly low pressure of ∌ 3 ± 1 kbar. This offers the possibility of studying a bare quasi-two-dimensional spin density wave quantum critical point, testing the T → 0 K limit of theories of Planckian dissipation and quantum criticality. Preliminary attempts to fit ρ(T) with a quantum critical spin fluctuation model, while encouraging, reveal a need for further, complementary measurements

    Use of Balloon-Tipped Catheters in the Critically Ill Child

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    A retrospective study of our experience in the placement of 19 consecutive balloon-tipped catheters in the pulmonary artery of 18 children disclosed that the procedure can be performed with relative ease in the intensive care unit without the aid of fluoroscopy. Insertion of the catheters was not associated with any serious complications. Catheter malfunction, however, occurred in 9 of 18 patients: balloon rupture in 6 and clot formation in 3. Comparison of pulmonary capillary pressure through a balloon-tipped catheter and venous pressure through a central venous line indicates that, in the absence of significant pulmonary disease requiring high positive end expiratory pressure, or significant left heart dysfunction, a central venous pressure line is frequently adequate for monitoring right heart pressures and as a guidance to fluid therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67256/2/10.1177_000992288202100302.pd

    The operationalized psychodynamic diagnostics system. Clinical relevance, reliability and validity

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    In this paper, we present a multiaxial system for psychodynamic diagnosis, which has attained wide usage in Germany in the last 10 years. First we will discuss the 4 operationalized psychodynamic diagnostics (OPD) axes: illness experience and treatment assumptions, relationships, mental conflicts, and structure, then clinical applications will be outlined. Focus psychodynamic formulations can be employed both with inpatients and with outpatients. Studies show good reliability in a research context and acceptable reliability for clinical purposes. Validity will be separately summarized as content, criterion, and construct validity. Validity studies indicate good validity for the individual axes. Numerous studies on the OPD indicate areas of possible improvement, for example for clinical purposes the OPD should be more practically formulated
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