System size, energy and pseudorapidity dependence of directed and elliptic flow at RHIC

PHOBOS measurements of elliptic flow are presented as a function of pseudorapidity, centrality, transverse momentum, energy and nuclear species. The elliptic flow in Cu-Cu is surprisingly large, particularly for the most central events. After scaling out the geometry through the use of an alternative form of eccentricity, called the participant eccentricity, which accounts for nucleon position fluctuations in the colliding nuclei, the relative magnitude of the elliptic flow in the Cu-Cu system is qualitatively similar to that measured in the Au-Au system.Comment: Presented at the 18th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions in Budapest, Hungary, Aug. 4-9, 200

Geoneutrinos in Borexino

This paper describes the Borexino detector and the high-radiopurity studies and tests that are integral part of the Borexino technology and development. The application of Borexino to the detection and studies of geoneutrinos is discussed.Comment: Conference: Neutrino Geophysics Honolulu, Hawaii December 14-16, 200

Fundamental study of flow field generated by rotorcraft blades using wide-field shadowgraph

The vortex trajectory and vortex wake generated by helicopter rotors are visualized using a wide-field shadowgraph technique. Use of a retro-reflective Scotchlite screen makes it possible to investigate the flow field generated by full-scale rotors. Tip vortex trajectories are visible in shadowgraphs for a range of tip Mach number of 0.38 to 0.60. The effect of the angle of attack is substantial. At an angle of attack greater than 8 degrees, the visibility of the vortex core is significant even at relatively low tip Mach numbers. The theoretical analysis of the sensitivity is carried out for a rotating blade. This analysis demonstrates that the sensitivity decreases with increasing dimensionless core radius and increases with increasing tip Mach number. The threshold value of the sensitivity is found to be 0.0015, below which the vortex core is not visible and above which it is visible. The effect of the optical path length is also discussed. Based on this investigation, it is concluded that the application of this wide-field shadowgraph technique to a large wind tunnel test should be feasible. In addition, two simultaneous shadowgraph views would allow three-dimensional reconstruction of vortex trajectories

Elliptic Flow, Initial Eccentricity and Elliptic Flow fluctuations in Heavy Ion Collisions at RHIC

We present measurements of elliptic flow and event-by-event fluctuations established by the PHOBOS experiment. Elliptic flow scaled by participant eccentricity is found to be similar for both systems when collisions with the same number of participants or the same particle area density are compared. The agreement of elliptic flow between Au+Au and Cu+Cu collisions provides evidence that the matter is created in the initial stage of relativistic heavy ion collisions with transverse granularity similar to that of the participant nucleons. The event-by-event fluctuation results reveal that the initial collision geometry is translated into the final state azimuthal particle distribution, leading to an event-by-event proportionality between the observed elliptic flow and initial eccentricity.Comment: To appear in the proceedings of the Lake Louise Winter Institute 2007. The proceedings of the institute will be published by World Scientifi

Energy and precious fuels requirements of fuel alcohol production. Volume 4: Appendices G and H, methanol from coal

Coal mine location, mining technology, energy consumption in mining, coal transport, and potential availability of coal are discussed. Methanol from coal is also discussed

A First Application of Independent Component Analysis to Extracting Structure from Stock Returns

This paper discusses the application of a modern signal processing technique known as independent component analysis (ICA) or blind source separation to multivariate financial time series such as a portfolio of stocks. The key idea of ICA is to linearly map the observed multivariate time series into a new space of statistically independent components (ICs). This can be viewed as a factorization of the portfolio since joint probabilities become simple products in the coordinate system of the ICs. We apply ICA to three years of daily returns of the 28 largest Japanese stocks and compare the results with those obtained using principal component analysis. The results indicate that the estimated ICs fall into two categories, (i) infrequent but large shocks (responsible for the major changes in the stock prices), and (ii) frequent smaller fluctuations (contributing little to the overall level of the stocks). We show that the overall stock price can be reconstructed surprisingly well by using a small number of thresholded weighted ICs. In contrast, when using shocks derived from principal components instead of independent components, the reconstructed price is less similar to the original one. Independent component analysis is a potentially powerful method of analyzing and understanding driving mechanisms in financial markets. There are further promising applications to risk management since ICA focuses on higher-order statistics.Information Systems Working Papers Serie

Exploring the importance of reflection in the control room

While currently difficult to measure or explicitly design for, evidence suggests that providing people with opportunities to reflect on experience must be recognized and valued during safety-critical work. We provide an insight into reflection as a mechanism that can help to maintain both individual and team goals. In the control room, reflection can be task-based, critical for the 'smooth' day-to-day operational performance of a socio-technical system, or can foster learning and organisational change by enabling new understandings gained from experience. In this position paper we argue that technology should be designed to support the reflective capacity of people. There are many interaction designs and artefacts that aim to support problem-solving, but very few that support self-reflection and group reflection. Traditional paradigms for safety-critical systems have focussed on ensuring the functional correctness of designs, minimising the time to complete tasks, etc. Work in the area of user experience design may be of increasing relevance when generating artefacts that aim to encourage reflection

Energy and system dependence of high-pTp_T triggered two-particle near-side correlations

Previous studies have indicated that the near-side peak of high-$p_T$ triggered correlations can be decomposed into two parts, the \textit{Jet} and the \textit{Ridge}. We present data on the yield per trigger of the \textit{Jet} and the \textit{Ridge} from $d+Au$, $Cu+Cu$ and $Au+Au$ collisions at $\sqrt{s_{NN}}$ = 62.4 GeV and 200 GeV and compare data on the \textit{Jet} to PYTHIA 8.1 simulations for $p+p$. PYTHIA describes the \textit{Jet} component up to a scaling factor, meaning that PYTHIA can provide a better understanding of the \textit{Ridge} by giving insight into the effects of the kinematic cuts. We present collision energy and system dependence of the \textit{Ridge} yield, which should help distinguish models for the production mechanism of the \textit{Ridge}.Comment: 4 pages, 6 figures, proceedings for Hot Quarks in Estes Park, Colorad

3D Relativistic Hydrodynamic Computations Using Lattice-QCD-Inspired Equations of State

In this communication, we report results of three-dimensional hydrodynamic computations, by using equations of state with a critical end point as suggested by the lattice QCD. Some of the results are an increase of the multiplicity in the mid-rapidity region and a larger elliptic-flow parameter v2. We discuss also the effcts of the initial-condition fluctuations and the continuous emission.Comment: 10 pages, 16 figures, prepared for Quark Matter 2005 Conferenc