Effect of High Free Stream Turbulence on Film Cooling Using Double Row of 30° Slant-Hole Injectors

In this study free stream turbulence levels from 7.3% to 17.8% are applied to film cooling over a flat plate with two rows of 30° slant holes using a wall jet as the main stream air supply and source of turbulence. Blowing ratios are varied from 0.25 to 2.0 and free stream velocities at injection range from 10 m/s to 85 m/s. A constant density ratio of 1.07 is kept throughout the experiment. Results show that for different magnitudes of blowing ratio free stream turbulence has a different influence on effectiveness. At the forward stations, where blow off was present at high blowing ratios, high free stream turbulence increased effectiveness. While at mid to aft stations for all blowing ratios high free stream turbulence decreased effectiveness. A correlation for effectiveness with a non-dimensional group of film cooling parameters is offered. The effectiveness correlated best 10 to 15 diameters after injection where blow off effects are no longer present, and before the very far downstream stations where uncertainties in the measurements were greater

Jet multiplicities as the QGP thermometer

It is proposed to use the energy behavior of mean multiplicities of jets propagating in a nuclear medium as the thermometer of this medium during the collision phases. The qualitative effects are demonstrated in the framework of the fixed coupling QCD with account of jet quenching.Comment: Modify version of hep-ph/0509344, 3 figure

Child Support: Interaction Between Private and Public Transfers

Child support is a private transfer that is integral to the means-tested public transfer system. Support payments generally lower the budget costs of welfare as well the incentives for parents to participate. The Child Support Enforcement (CSE) program, which establishes and enforces support obligations, also affects the incentives of the non-custodial parent donors and ultimately the distribution of incomes. While not formally income-tested, CSE still targets low-income families because so many custodial families are poor. This paper reviews the history of the CSE program; the economic rationale for government's role; trends in support awards and payments; the importance of child support to low-income families; the capacity of non-custodial parents to pay child support; trends in costs, financing and effectiveness of the CSE program; the effects of child support on behavior; equity issues in child support; and proposals for reform. Despite efficiency gains in the CSE program, especially in establishing paternity, a shift in the composition of cases has offset these improvements, causing support payments per custodial mother to rise only modestly in real terms.

Observation of modified hadronization in relativistic Au+Au collisions: a promising signature for deconfined quark-gluon matter

Measurements of identified particles from Au+Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV are reviewed. Emphasis is placed on nuclear modification, baryon-to-meson ratios, and elliptic flow at intermediate transverse momentum ($1.5 < p_T < 5$ GeV/c). Possible connections between (1) these measurements, (2) the running coupling for static quark anti-quark pairs at finite temperature, and (3) the creation of a deconfined quark-gluon phase are presented. Modifications to hadronization in Au+Au collisions are proposed as a likely signature for the creation of deconfined colored matter.Comment: 8 pages, 5 figures, invited talk at the Strange Quark Matter 2004 conference, Cape Town, South Afric

Finite Size Scaling for Low Energy Excitations in Integer Heisenberg Spin Chains

In this paper we study the finite size scaling for low energy excitations of $S=1$ and $S=2$ Heisenberg chains, using the density matrix renormalization group technique. A crossover from $1/L$ behavior (with $L$ as the chain length) for medium chain length to $1/L^2$ scaling for long chain length is found for excitations in the continuum band as the length of the open chain increases. Topological spin $S=1/2$ excitations are shown to give rise to the two lowest energy states for both open and periodic $S=1$ chains. In periodic chains these two excitations are ``confined'' next to each other, while for open chains they are two free edge 1/2 spins. The finite size scaling of the two lowest energy excitations of open $S=2$ chains is determined by coupling the two free edge $S=1$ spins. The gap and correlation length for $S=2$ open Heisenberg chains are shown to be 0.082 (in units of the exchange $J$) and 47, respectively.Comment: 4 pages (two column), PS file, to be appear as a PRB Brief Repor

Integrable versus Non-Integrable Spin Chain Impurity Models

Recent renormalization group studies of impurities in spin-1/2 chains appear to be inconsistent with Bethe ansatz results for a special integrable model. We study this system in more detail around the integrable point in parameter space and argue that this integrable impurity model corresponds to a non-generic multi-critical point. Using previous results on impurities in half-integer spin chains, a consistent renormalization group flow and phase diagram is proposed.Comment: 20 pages 11 figures obtainable from authors, REVTEX 3.

Systemic glucocorticoid use in Denmark: a population-based prevalence study

OBJECTIVES: Glucocorticoid (GC) use is widespread and associated with many adverse effects. Thus, it is important to ascertain GC utilisation patterns. In this study, we examined the annual prevalence of prescription users and amount of use of systemic GCs. DESIGN: Population-wide prevalence study. SETTING: The primary healthcare and hospital sectors in Denmark from 1999 to 2015. RESULTS: Approximately 3% of the Danish population redeemed at least one prescription for a systemic GC annually between 1999 and 2015, with annual prevalence remaining constant over the period. However, after adjusting for age and sex, we observed a decrease in annual prevalence from 1999 to 2015, with a prevalence ratio of 0.92 (95% CI 0.91 to 0.92). Annual prevalence was highest among the elderly (7.0%–8.2% among persons 65–79 years of age and 8.4%–10% among persons 80+ years of age). Prednisolone was the most frequently redeemed systemic GC, with annual prevalence increasing from 1.4% to 2.1% during the 1999–2015 period. The amount of systemic GCs provided to the hospital sector increased from 2.3 defined daily doses (DDD)/1000 inhabitants/day in 1999 to 3.5 DDD/1000 inhabitants/day in 2015, while the amount provided to the primary healthcare sector remained constant in the range of 10–11 DDD/1000 inhabitants/day. CONCLUSION: We found a high prevalence of systemic GC use of 3% with a remarkably high prevalence in elderly of up to 10%, wherefore continued awareness of its effects is mandated

Bond-versus-site doping models for off-chain-doped Haldane-gap system Y2_2 Ba Ni O5_5

Using the density matrix renormalization-group technique, we calculate the impurity energy levels for two different effective models of off-chain doping for quasi-one-dimensional Heisenberg chain compound Y$_2$ Ba Ni O$_5$: ferromagnetic bond doping and antiferromagnetic site spin-1/2 doping. Thresholds of the impurity strength for the appearance of localized states are found for both models. However, the ground-state and low-energy excitations for weak impurity strength are different for these two models and the difference can be detected by experiments.Comment: 5 pages, 5 eps figures included, to be published in Phys. Rev.