Hydrodynamic Evolution of Spherical Fireball In Relativistic Heavy Ion Collisions

Evolution process could be calculated from the relativistic hydrodynamic equation with certain estimated initial conditions about a single spherical fireball here. So one could estimate a kind of initial condition qualitatively with a possible energy density about $\epsilon_0\approx 1.9$ $GeV/fm^3$, based on this process to fit the experimental data at thermal freeze-out. The evolution from a cylindrical fireball will be discussed simply in a later chapter.Comment: 9 pages, 8 figure

Trade Liberalization and Trade Performance of Environmental Goods: Evidence from Asia-Pacific Economic Cooperation Members

In this article, we study the impact of trade liberalization, including reductions in both tariff and nontariff trade barriers, on environmental goods (EGs) exports. Using bilateral trade data from 20 Asia-Pacific Economic Cooperation members, we find that tariff reduction in an exporting country has a larger positive impact on its exports of EGs than tariff reduction in an importing country. Our results also show that a lower nontariff barrier in an importing country increases its imports of EGs. A considerable amount of heterogeneity also exists in subsample results based on countries’ income levels

Vibration parameter measurement using the temporal digital hologram sequence and windowed Fourier transform

AbstractReal time digital recording and numerical reconstruction of a temporal digital hologram sequence have become feasible in recent years. They provide a new measurement method which enjoys the valuable advantages of being full-field, noncontact and high precision. In this paper, a combined method of temporal digital hologram sequence and windowed Fourier transform is proposed to measure the kinematic parameters of random vibration. A series of holograms are recorded by CCD camera and the original phase can be reconstructed by Fresnel reconstruction algorithm. The three-dimensional windowed Fourier transform is used to filter noise in phase and extract the instantaneous kinematic parameters of the specimen, such as the displacement, velocity and acceleration. An experiment is conducted on a chloroprene rubber latex membrane. Results demonstrate that the proposed method determines the vibration parameters precisely and enjoys many merits

Hadronization Approach for a Quark-Gluon Plasma Formed in Relativistic Heavy Ion Collisions

A transport model is developed to describe hadron emission from a strongly coupled quark-gluon plasma formed in relativistic heavy ion collisions. The quark-gluon plasma is controlled by ideal hydrodynamics, and the hadron motion is characterized by a transport equation with loss and gain terms. The two sets of equations are coupled to each other, and the hadronization hypersurface is determined by both the hydrodynamic evolution and the hadron emission. The model is applied to calculate the transverse momentum distributions of mesons and baryons, and most of the results agree well with the experimental data at RHIC.Comment: 16 pages, 24 figures. Version accepted by PR

Jumps in oil prices: the role of economic news

Includes bibliographical references (pages 20-22).Published as: The Energy Journal, 1 vol.34, no. 3, pp.217-237, January 2013, https://doi.org/10.5547/01956574.34.3.10.Previous research has been unable to identify a strong link between crude oil prices and economic news. We reexamine this relationship using high frequency intraday data and relatively new methodology to estimate jumps in oil prices. We find a surprisingly strong correspondence between high frequency jumps in oil prices and the arrival of new economic information, with the largest jumps tending to be preceded identifiable economic news. These results indicate that oil prices respond very rapidly to new economic data in ways that appear consistent with economic theory, and also suggest that economic news, rather than speculation unrelated to the economic environment, drives jumps in oil prices

Is the price of crude responsive to macroeconomic news? A test of the stock-flow hypothesis

Includes bibliographical references (pages 26-28).Published as: Does the price of crude oil respond to macroeconomic news?, Journal of Futures Markets, vol.32, no. 6, pp.536-559, June 2012, https://doi.org/10.1002/fut.20525.A recent study indicates that the daily price of crude oil is mostly unresponsive to macroeconomic news, at times exhibiting response-coefficients that carry the “wrong sign”. The study concludes that the price of crude oil is predetermined to macro aggregates, and hence determined in a flow demand and flow supply framework. We make the economic argument that inferences on commodity price determination should be drawn from news responses only after the standard tests are subject to inventory (or stock) controls. Using both daily and intraday data for crude oil, and using rudimentary tools to isolate perceived inventory levels, we test for the stock-flow hypothesis for crude oil. We find only weak evidence on the role of inventory levels for crude oil. We also assess the extent to which the dynamics of the dollar plays in the results, and find its role to be limited. Overall, the prior conclusion that crude oil is priced primarily in a flow-environment is supported by our data. The initial (intraday) response in energy prices to macro news appears to be the result of noise trading