41,157 research outputs found
Data and software for article: Taylor-West, J. J., Balmforth, N. J., and Hogg, A. J. (2024) Lava delta formation: Mathematical modelling and laboratory experiments
Experimental and numerical data and scripts required to reproduce the results of Taylor-West, Balmforth, & Hogg 2024 "Lava delta formation: Mathematical modelling and laboratory experiments". Accepted to JGR: Earth Surfaces. doi:10.1029/2023JF00750
Data and software for article: Taylor-West, J. J., Balmforth, N. J., and Hogg, A. J. (2023) Lava delta formation: Mathematical modelling and laboratory experiments
Experimental and numerical data and scripts required to reproduce the results of Taylor-West, Balmforth, & Hogg 2023 "Lava delta formation: Mathematical modelling and laboratory experiments". Submitted to JGR: Earth Surfaces
Dam-breaking seiches
Experimental and theoretical models are used to explore the break of a
moraine dam by catastrophic erosional incision initiated by an
overtopping wave. The experiments are conducted in a rectangular tank
with an erodible barrier made from sand and grit. Theory combines
shallow-water hydrodynamics with an empirical model of erosion. The
models confirm that dams can be broken by a catastrophic incision.
However, the displacement wave does not break the dam in its first
passage but excites a long-lived seiche that repeatedly washes over the
dam. The Cumulative erosion of the downstream face by the overtopping
seiches eventually allows an incipient channel to form, and catastrophic
incision follows. Estimates are presented of the strength of the initial
disturbance required to break the dam, the maximum discharge and the
duration of the runaway incision
Dam breaking by wave-induced erosional incision
We present an experimental and theoretical study of whether a large
displacement wave can lead to catastrophic erosional incision of a
moraine damming a glacial lake. The laboratory experiments consist of
reservoirs held by barriers of granular materials in a glass tank; the
theoretical model combines the Saint-Venant equations of hydraulic
engineering with an empirical prescription for erosion. The results of
both the laboratory experiments and the numerical simulations indicate
that a single wave is generally unable to break the dam, but a
sufficiently large disturbance in an almost-filled reservoir creates a
seiche that can repeatedly overtop the dam. In such a case, the combined
effect of the multiple erosion events ultimately breaks the dam
A shocking display of synchrony
This article explores the Kuramoto model describing the synchronization of a population of coupled oscillators. Two versions of this model are considered: a discrete version suitable for a population with a finite number of oscillators, and a continuum model found in the limit of an infinite population. When the strength of the coupling between the oscillators exceeds a threshold, the oscillators partially synchronize. We explore the transition in the continuum model, which takes the form of a bifurcation of a discrete mode from a continuous spectrum. We use numerical methods and perturbation theory to study the patterns of synchronization that form beyond transition, and compare with the synchronization predicted by the discrete model. There are similarities with instabilities in ideal plasmas and inviscid fluids, but these are superficial
Solar Power in the Garden State
This special issue on energy and solar power in New Jersey was made possible because of the extensive portfolio of research centers and institutes at the Edward J. Bloustein School of Planning and Public Policy. Dr. Frank A. Felder, an Associate Research Professor, has been director of the School’s Center for Energy, Economic & Environmental Policy (CEEEP) since 2006. Frank is a nuclear engineer with a PhD degree from MIT, and he, along with his CEEEP colleague, Shankar N. Chandramowli, coauthored the main article in this issue of the Advance & Rutgers Report. CEEEP has worked extensively with the New Jersey Board of Public Utilities on projects, including New Jersey’s current Energy Master Plan.Shining Brightly: Bloustein's Centers of Excellence / by James W. Hughes and Joseph S. Seneca -- Solar Power in the Garden States / by Shankar N. Chandramowli and Frank A. Felder.Guest contributors include Shankar N. Chandramowli and Frank A. Felder, PhD, Director—Center for Energy, Economic and Environmental Policy at the Edward J. Bloustein School of Planning and Public PolicyReports published as Issue Paper Number 5, May 2011, in Advance & Rutgers Report, Special Issue
Turbulent mixing at a stable density interface : the variation of the buoyancy flux–gradient relation
Experiments conducted on mixing across a stable density interface in a turbulent Taylor–Couette flow show, for the first time, experimental evidence of an increase in mixing efficiency at large Richardson numbers. With increasing buoyancy gradient the buoyancy flux first passes a maximum, then decreases and at large values of the buoyancy gradient the flux increases again. Thus, the curve of buoyancy flux versus buoyancy gradient tends to be N-shaped (rather than simply bell shaped), a behaviour suggested by the model of Balmforth et al. (J. Fluid Mech. vol. 428, 1998, p. 349). The increase in mixing efficiency at large Richardson numbers is attributed to a scale separation of the eddies active in mixing at the interface; when the buoyancy gradient is large mean kinetic energy is injected at scales much smaller than the eddy size fixed by the gap width, thus decreasing the eddy turnover time. Observations show that there is no noticeable change in interface thickness when the mixing efficiency increases; it is the mixing mechanism that changes. The curves of buoyancy flux versus buoyancy gradient also show a large variability for identical experimental conditions. These variations occur at time scales one to two orders of magnitude larger than the eddy turnover time scale
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
First evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
A hierarchy of coupled maps
A large number of logistic maps are coupled together as a mathematical metaphor for complex natural systems with hierarchical organization. The elementary maps are first collected into globally coupled lattices. These lattices are then coupled together in a hierarchical way to form a system with many degrees of freedom. We summarize the behavior of the individual blocks, and then explore the dynamics of the hierarchy. We offer some ideas that guide our understanding of this type of system
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
Abstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
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