3,740 research outputs found
The Effect of wake Turbulence Intensity on Transition in a Compressor Cascade
Direct numerical simulations of separating flow along a section at midspan of a low-pressure V103 compressor cascade with periodically incoming wakes were performed. By varying the strength of the wake, its influence on both boundary layer separation and bypass transition were examined. Due to the presence of small-scale three-dimensional fluctuations in the wakes, the flow along the pressure surface undergoes bypass transition. Only in the weak-wake case, the boundary layer reaches a nearly-separated state between impinging wakes. In all simulations, the flow along the suction surface was found to separate. In the simulation with the strong wakes, separation is intermittently suppressed as the periodically passing wakes managed to trigger turbulent spots upstream of the location of separation. As these turbulent spots convect downstream, they locally suppress separation. © 2014 Springer Science+Business Media Dordrecht
Comparative study on growth and survival of larval and juvenile Dicentrarchus labrax rearing on rotifer and Artemia enriched with four different microalgae species
In the present study, two experiments were carried out, the first one at age from 4th to 24th days post hatching (dph) which include Dicentrarchus labrax larvae rearing on rotifer and Artemia enriched with four types of algae as follows: Chlorella salina, Dunaleilla salina, Nannochloropsis salina and Tetraselmis chuii (ch1, D1, N1 and T1). At the end of the experiment, mean body length of 5.4, 11.9, 11.0 and 10.01 mm and a survival rate of 79.4, 73.8, 63.5 and 30.0% were achieved. Larvae fed with algae cultured in basal medium of chcont, Dcont, Ncont and Tcont reached 9.1, 9.5, 8.0 and 8.0 mm with survival rate of 31.7, 40.4, 30.5 and 22.4% by 25 (dph), respectively. In the second trial, juvenile D. labrax (25 - 60 dph) fed with Artemia metanauplii, enriched by ch1 (the best result recommended from 1st experiment) increased their mean total length to 35.5±1.4 mm at age 60 dph. The total carbohydrate and total protein in the algae species used to enrich rotifer and Artemia significantly increased for ch1, D1, N1 and T1.Also total amino acid significantly increased at P < 0.001. The total fatty acid and total unsaturated fatty acid in the algae significantly increased (P < 0.001) for ch1, D1, N1 and T1 taking into consideration that the state of C22:6 significantly increased. The ch1 gave better growth and survival percentage followed by D1 for enrich Brachionus plicatilis and newly hatched Artemia
Constraint-based sequence mining using constraint programming
The goal of constraint-based sequence mining is to find sequences of symbols
that are included in a large number of input sequences and that satisfy some
constraints specified by the user. Many constraints have been proposed in the
literature, but a general framework is still missing. We investigate the use of
constraint programming as general framework for this task. We first identify
four categories of constraints that are applicable to sequence mining. We then
propose two constraint programming formulations. The first formulation
introduces a new global constraint called exists-embedding. This formulation is
the most efficient but does not support one type of constraint. To support such
constraints, we develop a second formulation that is more general but incurs
more overhead. Both formulations can use the projected database technique used
in specialised algorithms. Experiments demonstrate the flexibility towards
constraint-based settings and compare the approach to existing methods.Comment: In Integration of AI and OR Techniques in Constraint Programming
(CPAIOR), 201
Deterministic protocol for mapping a qubit to coherent state superpositions in a cavity
We introduce a new gate that transfers an arbitrary state of a qubit into a
superposition of two quasi-orthogonal coherent states of a cavity mode, with
opposite phases. This qcMAP gate is based on conditional qubit and cavity
operations exploiting the energy level dispersive shifts, in the regime where
they are much stronger than the cavity and qubit linewidths. The generation of
multi-component superpositions of quasi-orthogonal coherent states, non-local
entangled states of two resonators and multi-qubit GHZ states can be
efficiently achieved by this gate
Theory of remote entanglement via quantum-limited phase-preserving amplification
We show that a quantum-limited phase-preserving amplifier can act as a
which-path information eraser when followed by heterodyne detection. This 'beam
splitter with gain' implements a continuous joint measurement on the signal
sources. As an application, we propose heralded concurrent remote entanglement
generation between two qubits coupled dispersively to separate cavities.
Dissimilar qubit-cavity pairs can be made indistinguishable by simple
engineering of the cavity driving fields providing further experimental
flexibility and the prospect for scalability. Additionally, we find an analytic
solution for the stochastic master equation, a quantum filter, yielding a
thorough physical understanding of the nonlinear measurement process leading to
an entangled state of the qubits. We determine the concurrence of the entangled
states and analyze its dependence on losses and measurement inefficiencies.Comment: Main text (11 pages, 5 figures), updated to the published versio
Hardware-efficient autonomous quantum error correction
We propose a new method to autonomously correct for errors of a logical qubit
induced by energy relaxation. This scheme encodes the logical qubit as a
multi-component superposition of coherent states in a harmonic oscillator, more
specifically a cavity mode. The sequences of encoding, decoding and correction
operations employ the non-linearity provided by a single physical qubit coupled
to the cavity. We layout in detail how to implement these operations in a
practical system. This proposal directly addresses the task of building a
hardware-efficient and technically realizable quantum memory.Comment: 12 pages,6 figure
Convenient Synthesis of Some New Bi-heterocycles conataining 3-Aminoquinazolin-4(3H)-one and 1,2,4-Triazole moieties
Dicarboxylic acids, thiosemicarbazides and methylanthranilate reacted to give methyl-2-(3-(5-mercapto-4-s-1,2,4-triazol-3-yl)-3-oxoalkylamino)benzoates 4. The laters, cyclized with hydrazine hydrate to give 3-amino-2-((5-mercapto-4 substitued-1,2,4-triazol-3-yl)alkyl)quinazolin-4(3H)-ones 5 which expected to have biological effects
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