4,658 research outputs found
Topological superconductivity in the extended Kitaev-Heisenberg model
We study superconducting pairing in the doped Kitaev-Heisenberg model by
taking into account the recently proposed symmetric off-diagonal exchange
. By performing a mean-field analysis, we classify all possible
superconducting phases in terms of symmetry, explicitly taking into account
effects of spin-orbit coupling. Solving the resulting gap equations
self-consistently, we map out a phase diagram that involves several
topologically nontrivial states. For , we find a competition between
a time-reversal symmetry breaking chiral phase with Chern number and a
time-reversal symmetric nematic phase that breaks the rotational symmetry of
the lattice. On the other hand, for we find a time-reversal
symmetric phase that preserves all the lattice symmetries, thus yielding
clearly distinguishable experimental signatures for all superconducting phases.
Both of the time-reversal symmetric phases display a transition to a
non-trivial phase at high doping levels. Finally, we also
include a symmetry-allowed spin-orbit coupling kinetic energy and show that it
destroys a tentative symmetry protected topological order at lower doping
levels. However, it can be used to tune the time-reversal symmetric phases into
a non-trivial phase even at lower doping
CollegeMatchers, Inc: Business Plan & Market Overview
This thesis details the business plan of CollegeMatchers, Inc, including a market overview. CollegeMatchers is a quick, easy, and free on-campus marketplace, that strives to create self sustaining communities on campuses everywhere
Preparation And Characterization Of Meridionally Trischelated Rhenium(i) Terpyridine Dicarbonyl Complexes
Recent work has uncovered a synthetic route to a new series of meridionally coordinated tridentate terpyridine rhenium dicarbonyl complexes. The complex mer,cis-Re(tpy-κ3N)(CO)2Cl (1) undergoes facile chloride substitution to produce a variety of complexes of the type mer,cis-[Re(tpy-κ3N)(CO)2(L)]n, where L = CF3SO3 (2), CH3CN (3), CN (4), NC5H5 (5), PMe3 (6), PEt3 (7), PPh3 (8), P(OMe)3 (9), P(OEt)3 (10), P(OPh)3 (11) ), P(OiPr)3 (12), P(OMe)(Ph)2 (13). Complexes 1-13 absorb light throughout a significant portion of the visible spectrum. The electrochemistry of these compounds is discussed in relation to their observed π-acidity and their ability to significantly stabilize the lower oxidation state of rhenium relative to the tricarbonyl bipyridine systems. The complex mer,cis-Re(tpy-κ3N)(CO)2Cl (1) produces a first oxidation potential (reversible) that is 0.85 V (vs. SCE) less oxidizing relative to fac-Re(bpy)(CO)3Cl\u27s first oxidation potential (irreversible)
Detection of Interstellar C_2 and C_3 in the Small Magellanic Cloud
We report the detection of absorption from interstellar C_2 and C_3 toward
the moderately reddened star Sk 143, located in the near 'wing' region of the
SMC, in optical spectra obtained with the ESO VLT/UVES. These detections of C_2
(rotational levels J=0-8) and C_3 (J=0-12) absorption in the SMC are the first
beyond our Galaxy. The total abundances of C_2 and C_3 (relative to H_2) are
similar to those found in diffuse Galactic molecular clouds -- as previously
found for CH and CN -- despite the significantly lower average metallicity of
the SMC. Analysis of the rotational excitation of C_2 yields an estimated
kinetic temperature T_k ~ 25 K and a moderately high total hydrogen density n_H
~ 870 cm^-3 -- compared to the T_01 ~ 45 K and n_H ~ 85-300 cm^-3 obtained from
H_2. The populations of the lower rotational levels of C_3 are consistent with
an excitation temperature of about 34 K.Comment: accepted to MNRAS; 10 pages, 6 figure
A numerical investigation of laminar airfoil stall
The details of an interacting boundary layer algorithm capable of calculating large scale laminar separation past airfoils at low speeds is given. Rationale behind various convergence acceleration methods is given. It is shown that linear based acceleration methods are limited to 50% savings in convergence rate. A nonlinear extrapolation method is proposed and tested on two simple model problems. Savings exceed the 50% limitation of the previous methods. Boundary layer results for laminar flow past symmetric airfoils at zero incidence are presented as a test of the methods. Leading edge marginal separation results at finite Reynolds numbers are presented. Richardson extrapolation of successive calculations is used to improve accuracy. Results for a zero thickness uncambered plate at angle of attack are presented
Adeno-Associated Virus 8-Mediated Gene Therapy for Choroideremia: Preclinical Studies in in Vitro ind in Vivo Models
Choroideremia (CHM) is a slowly progressive X-linked retinal degeneration that results ultimately in total blindness due to loss of photoreceptors, retinal pigment epithelium, and choroid. CHM, the gene implicated in choroideremia, encodes Rab escort protein-1 (REP-1), which is involved in the post-translational activation via prenylation of Rab proteins. We evaluated AAV8.CBA.hCHM, a human CHM encoding recombinant adeno-associated virus serotype 8 (rAAV8) vector, which targets retinal cells efficiently, for therapeutic effect and safety in vitro and in vivo in a murine model of CHM. In vitro studies assayed the ability of the vector to produce functional REP-1 protein in established cell lines and in CHM patient derived primary fibroblasts. Assays included Western blots, immunofluorescent labeling, and a REP-1 functional assay which measured the ability of exogenous REP-1 to prenylate Rab proteins. The in vivo work used unilateral subretinal delivery of AAV8.hCHM to treat a murine model of CHM, with the effects of treatment evaluated with pupillometry, ophthalmoscopy, histology, and immunofluorescence analysis. The contralateral eye was treated with an AAV8.EGFP control. The results of the in vitro analysis demonstrated that the AAV8.CBA.hCHM vector was capable of inducing robust expression of REP-1 protein in a dose-responsive fashion in cultured cells, with the prenylation assay indicating that the exogenous REP-1 protein produced was capable of assisting in the activation of Rab proteins. This functional assay was also applied to CHM patient fibroblasts transduced with an AAV serotype 2 version of the vector and demonstrated that exogenous REP-1 produced in these cells was functional. The in vivo subretinal treatment of CHM mice with AAV8.CBA.hCHM resulted in the improvement of pupillary response in the treated eyes of some animals, as well as slowing of progression as judged by ophthalmoscopy. Histology of treated animals showed properly localized expression of human REP-1 and a significant improvement in outer retina health as determined by an increase in the thickness of the outer nuclear layer in treated eyes compared to controls. Combined, these results indicate that transduction with AAV8.CBA.hCHM reduces the biochemical and pathogenic defects in CHM both in vitro and in vivo and supports the application of AAV8 vectors in CHM gene therapy
Capture, Learning, and Synthesis of 3D Speaking Styles
Audio-driven 3D facial animation has been widely explored, but achieving
realistic, human-like performance is still unsolved. This is due to the lack of
available 3D datasets, models, and standard evaluation metrics. To address
this, we introduce a unique 4D face dataset with about 29 minutes of 4D scans
captured at 60 fps and synchronized audio from 12 speakers. We then train a
neural network on our dataset that factors identity from facial motion. The
learned model, VOCA (Voice Operated Character Animation) takes any speech
signal as input - even speech in languages other than English - and
realistically animates a wide range of adult faces. Conditioning on subject
labels during training allows the model to learn a variety of realistic
speaking styles. VOCA also provides animator controls to alter speaking style,
identity-dependent facial shape, and pose (i.e. head, jaw, and eyeball
rotations) during animation. To our knowledge, VOCA is the only realistic 3D
facial animation model that is readily applicable to unseen subjects without
retargeting. This makes VOCA suitable for tasks like in-game video, virtual
reality avatars, or any scenario in which the speaker, speech, or language is
not known in advance. We make the dataset and model available for research
purposes at http://voca.is.tue.mpg.de.Comment: To appear in CVPR 201
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