1,061 research outputs found
Two- and three-dimensional viscous computations of a hypersonic inlet flow
The three-dimensional parabolized Navier-Stokes code has been used to investigate the flow through a Mach 7.4 inlet. A two-dimensional parametric study of grid resolution, turbulence modeling and effect of gamma has been done and compared with experimental results. The results show that mesh resolution of the shock waves, real gas effects and turbulence length scaling are very important to get accurate results for hypersonic inlet flows. In addition a three-dimensional calculation of the Mach 7.4 inlet has been done on a straight sideplate configuration. The results show that the glancing shock/boundary layer interaction phenomena causes significant three-dimensional flow in the inlet
Validation of Slosh Modeling Approach Using STAR-CCM+
Without an adequate understanding of propellant slosh, the spacecraft attitude control system may be inadequate to control the spacecraft or there may be an unexpected loss of science observation time due to higher slosh settling times. Computational fluid dynamics (CFD) is used to model propellant slosh. STAR-CCM+ is a commercially available CFD code. This paper seeks to validate the CFD modeling approach via a comparison between STAR-CCM+ liquid slosh modeling results and experimental, empirically, and analytically derived results. The geometries examined are a bare right cylinder tank and a right cylinder with a single ring baffle
On Hopf algebras of dimension 4p
In this paper, we prove that a non-semisimple Hopf algebra H of dimension 4p
with p an odd prime over an algebraically closed field of characteristic zero
is pointed provided H contains more than two group-like elements. In
particular, we prove that non-semisimple Hopf algebras of dimensions 20, 28 and
44 are pointed or their duals are pointed, and this completes the
classification of Hopf algebras in these dimensions.Comment: Reference added, Typos corrected, 22 page
Synthesis and characterization of novel copolymeric resveratrol conjugates
Resveratrol (RSV), naturally found in plants, is known to have health benefits and has been proposed as a potential anticancer and cardioprotective drug. However, due to its molecular structure, it undergoes rapid metabolism in the body resulting in low bioavailability. Novel polymeric methoxy-poly(ethylene glycol)-block-poly(e-caprolactone) (mPEG-PCL) RSV conjugates with varying PCL chain lengths have been synthesised and formulated into micelles and/or nanoparticles for preliminary in vitro stability studies. RSV conjugated with mPEG2000-PCL9500 was found to have improved solubility and stability of RSV as compared to RSV alone. The length of the PCL chain was found to affect the micelle formation, hence the stability in physiological buffers and rat plasma
Aortic Coarctation Following Aortic Valve Replacement: Problem Solving with Multimodality Cardiac Imaging
published_or_final_versio
Two-Pendulum Model of Propellant Slosh in Europa Clipper PMD Tank
Model propellant slosh for Europa Clipper using two pendulums such that controls engineers can predict slosh behavior during the mission. Importance of predicting propellant slosh; (1) Sloshing changes CM (center of mass) of spacecraft and exerts forces and torques on spacecraft. (2) Avoid natural frequencies of structures. (3) Size ACS (Attitude Control Systems) thrusters to counteract forces and torques. Can model sloshing fluid as two pendulums with specific parameters (mass, length, damping)
Validation of Slosh Modeling Approach Using STAR-CCM+
Without an adequate understanding of propellant slosh, the spacecraft attitude control system may be inadequate to control the spacecraft or there may be an unexpected loss of science observation time due to higher slosh settling times. Computational fluid dynamics (CFD) is used to model propellant slosh. STAR-CCM+ is a commercially available CFD code. This paper presents a comparison between STAR-CCM+ liquid slosh modeling results and experimental, empirically, and analytically derived results. The geometries examined are a bare right cylinder tank and a right cylinde
On the Gauge Equivalence of Twisted Quantum Doubles of Elementary Abelian and Extra-Special 2-Groups
We establish braided tensor equivalences among module categories over the
twisted quantum double of a finite group defined by an extension of a group H
by an abelian group, with 3-cocycle inflated from a 3-cocycle on H. We also
prove that the canonical ribbon structure of the module category of any twisted
quantum double of a finite group is preserved by braided tensor equivalences.
We give two main applications: first, if G is an extra-special 2-group of width
at least 2, we show that the quantum double of G twisted by a 3-cocycle w is
gauge equivalent to a twisted quantum double of an elementary abelian 2-group
if, and only if, w^2 is trivial; second, we discuss the gauge equivalence
classes of twisted quantum doubles of groups of order 8, and classify the
braided tensor equivalence classes of these quasi-triangular quasi-bialgebras.
It turns out that there are exactly 20 such equivalence classes.Comment: 27 pages, LateX, a few of typos in v2 correcte
Information decomposition of symbolic sequences
We developed a non-parametric method of Information Decomposition (ID) of a
content of any symbolical sequence. The method is based on the calculation of
Shannon mutual information between analyzed and artificial symbolical
sequences, and allows the revealing of latent periodicity in any symbolical
sequence. We show the stability of the ID method in the case of a large number
of random letter changes in an analyzed symbolic sequence. We demonstrate the
possibilities of the method, analyzing both poems, and DNA and protein
sequences. In DNA and protein sequences we show the existence of many DNA and
amino acid sequences with different types and lengths of latent periodicity.
The possible origin of latent periodicity for different symbolical sequences is
discussed.Comment: 18 pages, 8 figure
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