4,210 research outputs found
Quantifying electronic correlation strength in a complex oxide: a combined DMFT and ARPES study of LaNiO
The electronic correlation strength is a basic quantity that characterizes
the physical properties of materials such as transition metal oxides.
Determining correlation strengths requires both precise definitions and a
careful comparison between experiment and theory. In this paper we define the
correlation strength via the magnitude of the electron self-energy near the
Fermi level. For the case of LaNiO, we obtain both the experimental and
theoretical mass enhancements by considering high resolution
angle-resolved photoemission spectroscopy (ARPES) measurements and density
functional + dynamical mean field theory (DFT + DMFT) calculations. We use
valence-band photoemission data to constrain the free parameters in the theory,
and demonstrate a quantitative agreement between the experiment and theory when
both the realistic crystal structure and strong electronic correlations are
taken into account. These results provide a benchmark for the accuracy of the
DFT+DMFT theoretical approach, and can serve as a test case when considering
other complex materials. By establishing the level of accuracy of the theory,
this work also will enable better quantitative predictions when engineering new
emergent properties in nickelate heterostructures.Comment: 10 pages, 5 figure
Dispersion and separation of nanostructured carbon in organic solvents
The present invention relates to dispersions of nanostructured carbon in organic solvents containing alkyl amide compounds and/or diamide compounds. The invention also relates to methods of dispersing nanostructured carbon in organic solvents and methods of mobilizing nanostructured carbon. Also disclosed are methods of determining the purity of nanostructured carbon
Interplay of Spin-Orbit Interactions, Dimensionality, and Octahedral Rotations in Semimetallic SrIrO
We employ reactive molecular-beam epitaxy to synthesize the metastable
perovskite SrIrO and utilize {\it in situ} angle-resolved photoemission
to reveal its electronic structure as an exotic narrow-band semimetal. We
discover remarkably narrow bands which originate from a confluence of strong
spin-orbit interactions, dimensionality, and both in- and out-of-plane IrO
octahedral rotations. The partial occupation of numerous bands with strongly
mixed orbital characters signals the breakdown of the single-band Mott picture
that characterizes its insulating two-dimensional counterpart,
SrIrO, illustrating the power of structure-property relations for
manipulating the subtle balance between spin-orbit interactions and
electron-electron interactions
Characterisation of the new EpCAM-specific antibody HO-3: implications for trifunctional antibody immunotherapy of cancer
Epithelial cell adhesion molecule EpCAM is a transmembrane glycoprotein that is frequently overexpressed in a variety of carcinomas. This pan-carcinoma antigen has served as the target for a plethora of immunotherapies. Innovative therapeutic approaches include the use of trifunctional antibodies (trAbs) that recruit and activate different types of immune effector cells at the tumour site. The trAb catumaxomab has dual specificity for EpCAM and CD3. In patients with malignant ascites, catumaxomab significantly increased the paracentesis-free interval, corroborating the high efficacy of this therapeutic antibody. Here, we characterised the monoclonal antibody (mAb) HO-3, that is, the EpCAM-binding arm of catumaxomab. Peptide mapping indicated that HO-3 recognises a discontinuous epitope, having three binding sites in the extracellular region of EpCAM. Studies with glycosylation-deficient mutants showed that mAb HO-3 recognised EpCAM independently of its glycosylation status. High-affinity binding was not only detected for mAb HO-3, but also for the monovalent EpCAM-binding arm of catumaxomab with an excellent KD of 5.6 × 10−10 M. Furthermore, trAb catumaxomab was at least a 1000-fold more effective in eliciting the eradication of tumour cells by effector peripheral blood mononuclear cells compared with mAb HO-3. These findings suggest the great therapeutic potential of trAbs and clearly speak in favour of EpCAM-directed cancer immunotherapies
Computational Fluid Dynamics (CFD) applications in rocket propulsion analysis and design
Computational Fluid Dynamics (CFD) has been used in recent applications to affect subcomponent designs in liquid propulsion rocket engines. This paper elucidates three such applications for turbine stage, pump stage, and combustor chamber geometries. Details of these applications include the development of a high turning airfoil for a gas generator (GG) powered, liquid oxygen (LOX) turbopump, single-stage turbine using CFD as an integral part of the design process. CFD application to pump stage design has emphasized analysis of inducers, impellers, and diffuser/volute sections. Improvements in pump stage impeller discharge flow uniformity have been seen through CFD optimization on coarse grid models. In the area of combustor design, recent CFD analysis of a film cooled ablating combustion chamber has been used to quantify the interaction between film cooling rate, chamber wall contraction angle, and geometry and their effects of these quantities on local wall temperature. The results are currently guiding combustion chamber design and coolant flow rate for an upcoming subcomponent test. Critical aspects of successful integration of CFD into the design cycle includes a close-coupling of CFD and design organizations, quick turnaround of parametric analyses once a baseline CFD benchmark has been established, and the use of CFD methodology and approaches that address pertinent design issues. In this latter area, some problem details can be simplified while retaining key physical aspects to maintain analytical integrity
Improved limits on nuebar emission from mu+ decay
We investigated mu+ decays at rest produced at the ISIS beam stop target.
Lepton flavor (LF) conservation has been tested by searching for \nueb via the
detection reaction p(\nueb,e+)n. No \nueb signal from LF violating mu+ decays
was identified. We extract upper limits of the branching ratio for the LF
violating decay mu+ -> e+ \nueb \nu compared to the Standard Model (SM) mu+ ->
e+ nue numub decay: BR < 0.9(1.7)x10^{-3} (90%CL) depending on the spectral
distribution of \nueb characterized by the Michel parameter rho=0.75 (0.0).
These results improve earlier limits by one order of magnitude and restrict
extensions of the SM in which \nueb emission from mu+ decay is allowed with
considerable strength. The decay \mupdeb as source for the \nueb signal
observed in the LSND experiment can be excluded.Comment: 10 pages, including 1 figure, 1 tabl
The quantum vacuum at the foundations of classical electrodynamics
In the classical theory of electromagnetism, the permittivity and the
permeability of free space are constants whose magnitudes do not seem to
possess any deeper physical meaning. By replacing the free space of classical
physics with the quantum notion of the vacuum, we speculate that the values of
the aforementioned constants could arise from the polarization and
magnetization of virtual pairs in vacuum. A classical dispersion model with
parameters determined by quantum and particle physics is employed to estimate
their values. We find the correct orders of magnitude. Additionally, our simple
assumptions yield an independent estimate for the number of charged elementary
particles based on the known values of the permittivity and the permeability,
and for the volume of a virtual pair. Such interpretation would provide an
intriguing connection between the celebrated theory of classical
electromagnetism and the quantum theory in the weak field limit.Comment: Accepted in Applied Physics B: Special Issue for the 50 years of the
laser. Comments are welcome
Mutual coupling effects on antenna radiation pattern: An experimental study applied to interferometric radiometers
The Erasmus programme for postgraduate education in orthodontics in Europe: an update of the guidelines
In 1989, the ERASMUS Bureau of the European Cultural Foundation of the Commission of the European Communities funded the development of a new 3-year curriculum for postgraduate education in orthodontics. The new curriculum was created by directors for orthodontic education representing 15 European countries. The curriculum entitled ‘Three years Postgraduate Programme in Orthodontics: the Final Report of the Erasmus Project' was published 1992. In 2012, the ‘Network of Erasmus Based European Orthodontic Programmes' developed and approved an updated version of the guidelines. The core programme consists of eight sections: general biological and medical subjects; basic orthodontic subjects; general orthodontic subjects; orthodontic techniques; interdisciplinary subjects; management of health and safety; practice management, administration, and ethics; extramural educational activities. The programme goals and objectives are described and the competencies to be reached are outlined. These guidelines may serve as a baseline for programme development and quality assessment for postgraduate programme directors, national associations, and governmental bodies and could assist future residents when selecting a postgraduate programm
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