Measurements of Heavy Flavor and Di-electron Production at STAR

Heavy quarks are produced early in the relativistic heavy ion collisions, and provide an excellent probe into the hot and dense nuclear matter created at RHIC. In these proceedings, we will discuss recent STAR measurements of heavy flavor production, to investigate the heavy quark interaction with the medium. Electromagnetic probes, such as electrons, provide information on the various stages of the medium evolution without modification by final stage interactions. Di-electron production measurements by STAR will also be discussed.Comment: 5 pages, 6 figures, proceedings for CPOD201

Full Daytime Sub-Ambient Radiative Cooling in Commercial-like Paints with High Figure of Merit

Radiative cooling is a passive cooling technology that acts by reflecting sunlight and emitting radiation in the sky window. Although highly desirable, full daytime sub-ambient radiative cooling in commercial-like single-layer particle-matrix paints has not been achieved. Here, we demonstrate full daytime sub-ambient radiative cooling in CaCO3-acrylic paint by using large band gap CaCO3 fillers, a high particle concentration of 60%, and a broad size distribution. Our paint shows a high solar reflectance of 95.5% and a high normal emissivity of 0.94 in the sky window. Field tests show cooling power exceeding 37 W/m2 and a surface temperature of \u3e1.7 degrees C below ambient at noon. A figure of merit RC is proposed to compare the cooling performance independent of weather conditions. The standard RC of our paint is 0.49, among the best radiative cooling performances, while offering the benefits of convenient paint form, low cost, and compatibility with commercial paint fabrication processes

Voltage dependent director of a homeotropic negative liquid crystal cell

Copyright © 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 93 (2008) and may be found at http://link.aip.org/link/?APPLAB/93/031909/1Thin layers of obliquely (60° to normal) thermally evaporated SiOx lead to homeotropic alignment of a nematic liquid crystal (LC) having negative dielectric anisotropy. Under application of an ac voltage the director, as characterized by the fully leaky waveguide technique, is found to realign with a voltage controlled tilt along the evaporation direction. This behavior is in complete contrast with that of a LC having positive dielectric anisotropy and may have important implications for modern LC display technology

Optical Evaluation on Delamination Buckling of Composite Laminate with Impact Damage

The delamination buckling and growth behaviors of a cross-ply composite laminate with damage induced by low velocity impact are investigated optically using three-dimensional digital image correlation (3D-DIC) method. For the 3D deformation measurement, the 3D-DIC setup comprised of two CCD cameras was adopted. The rectangle specimen was impacted under the impact energy of 7.0 J using a drop-weight testing machine, and the impact damage was detected by means of X-ray nondestructive evaluation (NDE) technique. The 3D deformation field measured with the optical system clearly reveals that the delamination buckling characteristic of the specimen mainly appears local deformation mode under compression after impact test. Moreover, the behavior of delamination growth evaluated by the 3D-DIC optical method reasonably agrees with the NDE observed damage result after compression

A Sequential Circuit-Based IP Watermarking Algorithm for Multiple Scan Chains in Design-for-Test

In Very Large Scale Integrated Circuits (VLSI) design, the existing Design-for-Test(DFT) based watermarking techniques usually insert watermark through reordering scan cells, which causes large resource overhead, low security and coverage rate of watermark detection. A novel scheme was proposed to watermark multiple scan chains in DFT for solving the problems. The proposed scheme adopts DFT scan test model of VLSI design, and uses a Linear Feedback Shift Register (LFSR) for pseudo random test vector generation. All of the test vectors are shifted in scan input for the construction of multiple scan chains with minimum correlation. Specific registers in multiple scan chains will be changed by the watermark circuit for watermarking the design. The watermark can be effectively detected without interference with normal function of the circuit, even after the chip is packaged. The experimental results on several ISCAS benchmarks show that the proposed scheme has lower resource overhead, probability of coincidence and higher coverage rate of watermark detection by comparing with the existing methods

Risk assessment of critical time to renewable operation with steady-state security region

PS10: Risk Assessment in Power System Operation: ID 371Uncertain and variable characteristics of renewable energy resources introduce challenges to power system operation. A normal operating point might be drifted towards an unreliable operating point due to stochastic outputs od renewables. This paper proposes a novel method for estimating critical time to unreliable operating point with steady-state constraints. In this work, a stochastic differential equation is employed to describe the distribution of renewables with predictable tendency and stochastic errors of prediction; meanwhile, the DC power flow based steady-state security region is used to restrict the injected space. To find the critical time that uncontrollable renewables leave the security region, according the flexibility requirements defined by NERC, the uncontrollable region is identified with the Fourier-Motzkin elimination first. And then, by solving the Chebychev center problem, the critical distance for variable renewable outputs is obtained. Finally, an analytical solution of expected exit-time for renewable outputs leaving the security region is given with the Martingale stopping theorem. The proposed method can be used to construct the condition-driven risk indicators. An illustrative example is employed to demonstrate and validate the proposed method.postprin