556 research outputs found
Stochastic simulation of non-stationary continuous multifractal time series
No full textIntermittency is an ubiquitous property of fully developed turbulence, for Eulerian and Lagrangian fields, and for velocity, passive and active scalars. Intermittency corresponds to multi-scale high fluctuations, with some underlying long-range correlations. Such property is usually characterized using scaling approaches, verified using experimental or numerical data. However there are only few studies devoted to the generation of continuous stochastic processes having non-stationary multifractal properties, able to mimic Eulerian or Lagrangian velocity or passive scalar time series. Here we review recent works on this topic, and we provide stochastic simulations in order to verify the theoretical predictions. In the lognormal framework we provide a plane expressing the scale invariant properties of these simulations
Three-component velocity measurements in a momentum-conserving, axisymmetric, turbulent jet
No full textExperiments have been performed on a momentum conserving axisymmetric turbulent jet, the turbulence characteristics of which are well known [1]. Simultaneous three-component velocity measurements are acquired with high spatial and temporal resolution, using a new triple-sensor hotwire probe. Velocity and directional calibrations are performed using a dedicated automatic calibration system. Two experiments are performed; one for capturing the average velocity field in a 3D volume, and one for investigating the turbulence spectra in specific points in space. In the first experiment, measurements are performed in 9 equidistant cross-planes, from 10- to 50-diameters downstream of the nozzle using a computer-controlled traversing system. The spatial resolution is as low as 1 mm and the sampling rate was 10 kHz. In the second experiment, long velocity time histories are acquired with 50 kHz sampling rate to perform power spectral density computations for each velocity component. Preliminary results of velocity capture confirm the general characteristics of the turbulent jet. The power spectra at different positions indicate that the turbulent fluctuations are not isotropic at lower frequencies
Joint scaling analysis of atmospheric velocity and wind power plant production
No full textIn a context of energy transition, wind energy is a source of clean energy with the potential of partially satisfying the growing demand. The main problem of this type of energy, and other types of renewable energy remains the discontinuity of the electric power produced in different scales, inducing large fluctuations also called intermittency. This intermittency of wind energy is inherent to the turbulent nature of wind. Here, we consider the relation between velocity and power output with two wind turbine databases. We focus on joint relations with Fourrier analysis, empirical mode decomposition (EMD), Time-dependent intrinsic correlation (TDIC). We also consider the causality using a new method of analysis of the causality between two time series
Effect of FRP confinement on bond strength of hooked bars: Normal-strength concrete structures
No full textTo assess the viability of the external confinement of normal-strength concrete beam-column joints with carbon fiber-reinforced polymer (CFRP) sheets in increasing the bond strength of hooked bars anchored in the joints, 12 hooked bar specimens were tested. The variables were beam tensile bar size, anchorage length, mode of confinement of the beam hooked bars in the beam-column joint (whether the hooked bars were anchored within or outside the column reinforcement cage, denoted as confined specimens or unconfined specimens), and presence or absence of FRP wraps. The specimen simulated the rigid connection of a cantilever beam to a column. The tensile beam reinforcement consisted of two bars anchored in the base column using hooked-bar anchorages. Test results indicated that FRP sheets were effective in increasing the anchorage capacity and the ductility of the load-deflection history for both unconfined and confined specimens. However, FRP sheets had a more significant influence on unconfined specimens than companion confined specimens. As compared with unconfined specimens without FRP wrapping, unconfined FRP specimens had an average of a 23percent increase in bond strength, confined non-FRP specimens had an average 30percent increase in bond strength, and confined FRP specimens had an increase of 54percent. © 2009 ASCE.*ACI, 2005, ACI31805ACI318R05; ASTM, 2004, 2004 ANN BOOK ASTM S, V04.08; Ghobarah A, 2005, J COMPOS CONSTR, V9, P408, DOI 10.1061-(ASCE)1090-0268(2005)9:5(408); Hamad BS, 2004, J COMPOS CONSTR, V8, P14, DOI 10.1061-(ASCE)1090-0268(2004)8:1(14); Hamad BS, 2004, ACI STRUCT J, V101, P747; Hamad BS, 2005, J COMPOS CONSTR, V9, P44, DOI 10.1061-(ASCE)1090-0268(2005)9:1(44); Hamad BS, 2004, J COMPOS CONSTR, V8, P248, DOI 10.1061-(ASCE)1090-0268(2004)8:3(248); Kono S, 1998, P 2 INT C COMP INFR, P343; Pantelides CP, 2008, J COMPOS CONSTR, V12, P435, DOI 10.1061-(ASCE)1090-0268(2008)12:4(435)1
A Circulating MicroRNA Profile in a Laser-Induced Mouse Model of Choroidal Neovascularization
No full textFunding: This research was funded by the Deutsche Forschungsgemeinschaft (GR5065/1-1). Author Contributions: Conceptualization, F.G. and B.H.F.W.; Data curation, T.S.; Formal analysis, P.B., M.K., A.A., and T.S.; Funding acquisition, C.K. and F.G.; Investigation, M.K. and B.H.F.W.; Methodology, C.K. and A.A.;Project administration, B.H.F.W.; Resources, M.K., A.A., T.L., and F.G.; Software, C.K. and T.S.; Supervision, T.L., F.G., and B.H.F.W.; Validation, P.B.; Visualization, C.K.; Writing—original draft, C.K. and P.B.; Writing—review & editing, B.H.F.W. All authors have read and agreed to the published version of the manuscript.Peer reviewe
Islamisation or Malaynisation? : a study on the role of Islamic law in the economic development of Malaysia : 1969-1993
No full textThe thesis examines the role of Islam and Shariah (Islamic law) in the
economic development of Malaysia and it rejects the assumption that Islam and
Shariah inhibit economic development. In contemporary Malaysia, there are two
'policies' adopted by the Government. Firstly, 'Islamisation' which is for the
advancement of Islamic law and institution building. Secondly, 'Malaynisation' which
promotes the socio-economic development of the Malay ethnic group. The study
adopts a holistic approach which covers the political economy of law in Malaysia.
The thesis explores the relationship between the two policies considering in
particular whether they are essentially the same. The study covers the pre-colonial,
colonial and post-colonial periods although the focus is on the post-1969 period which
involved the application of the New Economic Policy (NEP).
The NEP was a pro-Malay Policy to rectif,' the economic imbalance of the
Malays vis-à-vis other communities. Therefore, the focus of this thesis is on the Malay-
Muslim population of Peninsular Malaysia who form the bulk of the Bumiputera
(indigenous people).
Two Bum iputera and Islamic organisations, Bank Islam (BIIMB) and Tabung Haji
(TH) as well as the Bumiputera unit trust scheme, Amanah Saham Nasional (ASN) are
used as the case studies. Their establishment, structure and organisation are examined.
There is a specific focus on the extent to which they are examples of Islamisation or
Malaynisation.
It is clear that in contemporary Malaysia, Islam and Shariah are being used by
the Government to promote economic development. Islamic values have been used to
further Malay economic participation in the commercial sector. As a consequence, the
economic position of many Malay-Muslims has greatly improved. However, the
Government position is questioned by the Islamic opposition who say that the
Islamisation policy in many respects is either contrary to Islam or merely cosmetic, and
want a 'pure' Islamic approach. The thesis therefore involves a critical examination of
the perspectives of both the Government and the Islamic opposition
(Re)organizing circular design projects: Four tool applications and reflections
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Integral Design & Managemen
Superconducting flux qubits: Quantum chains and tunable qubits
No full textThis thesis presents results of theoretical and experimental work on superconducting persistent-current flux quantum bits. These qubits are promising candidates for the implementation of scalable quantum information processing. This work focuses on the study of one dimensional chains of inductively coupled flux qubits and on qubits with a tunable energy gap. Chains of flux qubits can be used as models of quantum spin chains, one of the most basic systems in many-body physics that has been extensively studied theoretically. The ability to design and tune the qubit and coupling parameters enables exploration of different phase regimes during measurements, in parameter regimes that are not accessible with magnetic materials. The study of the dynamics of quantum waves in an artificial spin chain can also be used to explore novel quantum phenomena with possible applications in quantum computing. Tunability of the minimal energy splitting (the gap) enables one to rapidly bring the flux qubit in and out of resonance with other quantum systems, including a harmonic oscillator. With tunable qubits it also becomes possible to create inter-qubit couplings of different vector nature, using magnetic fluxes. This permits the design of various interaction Hamiltonians for multiple qubit systems. These operations can be performed at the degeneracy point of the qubit, where coherence properties are optimal. Therefore the tunable flux qubit provides an attractive component for the implementation of scalable quantum computation.Kavli Institute of Nanoscience DelftApplied Science
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