4,159 research outputs found
Electron Electric Dipole Moment induced by Octet-Colored Scalars
An appended sector of two octet-colored scalars, each an electroweak doublet,
is an interesting extension of the simple two Higgs doublet model motivated by
the minimal flavor violation. Their rich CP violating interaction gives rise to
a sizable electron electric dipole moment, besides the quark electric dipole
moment via the two-loop contribution of Barr-Zee mechanism.Comment: 8 pages, 2 figure
Delayed presentation of cerebellar and spinal cord infarction as a complication of computed tomography-guided transthoracic lung biopsy: a case report
INTRODUCTION: Computed tomography-guided transthoracic needle biopsy is a common diagnostic procedure that is associated with various complications including pneumothorax, parenchymal hemorrhage, and hemoptysis. A systemic air embolism is a very rare (0.06 to 0.21%) but potentially fatal complication. CASE PRESENTATION: A 70-year-old Korean male was admitted to our hospital for evaluation of a solitary pulmonary nodule located adjacent to the right inferior pulmonary vein in the medial basal segment of the right lower lobe. A computed tomography-guided needle biopsy was performed by a radiologist using a coaxial needle. A computed tomography image obtained immediately after the biopsy showed intraluminal free air in the proximal ascending aorta. He complained of a mild electrical current sensation in both lower extremities. After three hours he complained of neurological deficit in both lower extremities as well as voiding difficulty. The brain and spine magnetic resonance images showed a right cerebellar and spinal cord infarction at the T8-10 levels. CONCLUSIONS: We report a case of air embolism to the cerebellum and spinal cord causing infarction presenting with an initial symptom of mild electrical current sensation in both lower extremities during the transthoracic needle biopsy. For this potentially fatal complication, early recognition, followed by prompt therapy is critical to reducing morbidity and mortality
Low energy proton-proton scattering in effective field theory
Low energy proton-proton scattering is studied in pionless effective field
theory. Employing the dimensional regularization and MS-bar and power
divergence subtraction schemes for loop calculation, we calculate the
scattering amplitude in 1S0 channel up to next-to-next-to leading order and fix
low-energy constants that appear in the amplitude by effective range
parameters. We study regularization scheme and scale dependence in separation
of Coulomb interaction from the scattering length and effective range for the
S-wave proton-proton scattering.Comment: 23 pages, 6 eps figures, revised considerably, accepted for
publication in Phys. Rev.
Competing spin-fluctuations in SrRuO and their tuning through epitaxial strain
In this study, we report the magnetic energy landscape of Sr2RuO4 employing
the generalized Bloch approach within density functional theory. We identify
the two dominant magnetic instabilities, ferromagnetic and spin-density-wave,
together with other predominant instabilities. We show that epitaxial strain
can change the overall magnetic tendency of the system, and tune the relative
weight of the various magnetic instabilities in the system. Especially, the
balance between spin-density wave and ferromagnetic instabilities can be
controlled by the strain, and, eventually can lead to the new magnetic phases
as well as superconducting phases with possibly altered pairing channels. Our
findings are compared with previous theoretical models and experimental reports
for the various magnetic features of the system and offer a first-principles
explanation to them
Tunable electronic and magnetic phases in layered ruthenates: SrRuO3-SrTiO3 heterostructure upon strain
Layered ruthenates are a unique class of systems which manifests a variety of
electronic and magnetic features emerged from competing energy scales. At the
heart of such features lies the multi-orbital physics, especially, the
orbital-selective behavior. Here, we propose that the SrRuO3-SrTiO3
heterostructure is a highly tunable platform to obtain the various emergent
properties. Employing the density functional theory plus dynamical mean-field
theory, we thoroughly investigate the orbital-dependent physics of the system
and identify the competing magnetic fluctuations. We show that the epitaxial
strain drives the system towards multi-orbital or orbital selective Mott phases
from the Hund metal regime. At the same time, the two different types of static
magnetism are stabilized, ferromagnetism and checkerboard antiferromagnetism,
from the competition with the spin-density wave instability.Comment: 5 pages, 3 figures in the main text, Supplemental Material is
include
Development of Pd Alloy Hydrogen Separation Membranes with Dense/Porous Hybrid Structure for High Hydrogen Perm-Selectivity
For the commercial applications of hydrogen separation membranes, both high hydrogen selectivity and permeability (i.e., perm-selectivity) are required. However, it has been difficult to fabricate thin, dense Pd alloy composite membranes on porous metal support that have a pore-free surface and an open structure at the interface between the Pd alloy films and the metal support in order to obtain the required properties simultaneously. In this study, we fabricated Pd alloy hydrogen separation membranes with dense/porous hybrid structure for high hydrogen perm-selectivity. The hydrogen selectivity of this membrane increased owing to the dense and pore-free microstructure of the membrane surface. The hydrogen permeation flux also was remarkably improved by the formation of an open microstructure with numerous open voids at the interface and by an effective reduction in the membrane thickness as a result of the porous structure formed within the Pd alloy films
Tailorable, 3D microfabrication for photonic applications: Two-polymer microtransfer molding
For photonic devices, extending beyond the planar regime to the third dimension can allow a higher degree of integration and novel functionalities for applications such as photonic crystals and integrated optical circuits. Although conventional photolithography can achieve both high quality and structural control, it is still costly and slow for threedimensional (3D) fabrication. Moreover, as diverse functional polymers emerge, there is potential to develop new techniques for quick and economical fabrication of 3D structures. We present a 3D microfabrication technique based on the soft lithographic technique, called two-polymer microtransfer molding (2P-µTM) to accomplish low cost, high structural fidelity and tailorable 3D microfabrication for polymers. Using 2P-µTM, highly layered polymeric microstructures are achievable by stacking planar structures layer by layer. For increased processing control, the surface chemistry of the polymers is characterized as a function of changing ultraviolet dosage to optimize yield in layer transfer. We discuss the application of the 2P-µTM to build polymer templates for woodpile photonic crystals, and demonstrate methods for converting the polymer templates to dielectric and metallic photonic crystal structures. Finally, we will show that 2P-µTM is promising for fabricating 3D polymeric optical waveguides
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