Composite scalars at CERN LEP: Constraining technicolor theories

LEPI and LEPII data can be used to constrain technicolor models with light, neutral pseudo-Nambu-Goldstone bosons, Pa. We use published limits on branching ratios and cross sections for final states with photons, large missing energy, jet pairs, and b bbar pairs to constrain the anomalous Pa Z0 Z0, Pa Z0 photon, and Pa photon photon couplings. From these results, we derive bounds on the size of the technicolor gauge group and the number of technifermion doublets in models such as Low-scale Technicolor

Space shuttle OMS helium regulator design and development

Analysis, design, fabrication and design verification testing was conducted on the technological feasiblity of the helium pressurization regulator for the space shuttle orbital maneuvering system application. A prototype regulator was fabricated which was a single-stage design featuring the most reliable and lowest cost concept. A tradeoff study on regulator concepts indicated that a single-stage regulator with a lever arm between the valve and the actuator section would offer significant weight savings. Damping concepts were tested to determine the amount of damping required to restrict actuator travel during vibration. Component design parameters such as spring rates, effective area, contamination cutting, and damping were determined by test prior to regulator final assembly. The unit was subjected to performance testing at widely ranging flow rates, temperatures, inlet pressures, and random vibration levels. A test plan for propellant compatibility and extended life tests is included

Dynamics and structure of an aging binary colloidal glass

We study aging in a colloidal suspension consisting of micron-sized particles in a liquid. This system is made glassy by increasing the particle concentration. We observe samples composed of particles of two sizes, with a size ratio of 1:2.1 and a volume fraction ratio 1:6, using fast laser scanning confocal microscopy. This technique yields real-time, three-dimensional movies deep inside the colloidal glass. Specifically, we look at how the size, motion and structural organization of the particles relate to the overall aging of the glass. Particles move in spatially heterogeneous cooperative groups. These mobile regions tend to be richer in small particles, and these small particles facilitate the motion of nearby particles of both sizes.Comment: 7 pages; submitted to Phys. Rev. E. Revised with 1 new figure, improved tex

An investigation into the perception of spatial techniques used in multi-channel electroacoustic music

The paper reports on an experiment designed to examine the perception of the spatial attributes of envelopment and engulfment in spatial techniques used in multichannel electroacoustic music. Four spatial techniques were examined, they were: (i) Timbre Spatialisation [1], (ii) Spectral Splitting [2], (iii) Amplitude Point Source [3], and the proposed (iv) Dynamic Spectral Spatialisation technique. The multi-channel loudspeaker configuration consisted of 16 loudspeakers, eight horizontal and eight elevated. The experiment was design whereby the four above mentioned spatial techniques were presented in three conditions: (i) Horizontal only, (ii) Elevated only, and (iii) Horizontal and Elevated, referred to as Three Dimensional (3D), loudspeaker configurations. The experiment took place in the Spatialisation Auditory Display Environment (SpADE) at the University of Limerick and has physical attributes that conform to the ITU-R BS.1116-1 listening room standard [4]. Each participant individually undertook a listening experiment whereby they were asked to evaluate each spatial technique presented in the three conditions for perceived levels of envelopment and engulfment. A factorial analysis of variance (ANOVA) was performed on the envelopment and engulfment ratings. The results of the analysis revealed a significant main effect for spatial techniques and loudspeaker configurations for both spatial attributes. Participants rated the Dynamic Spectral Spatialisation technique highest for levels of envelopment and engulfment. The Horizontal loudspeaker configuration was rated highest for envelopment and the Elevated loudspeaker configuration was rated highest for engulfment

A Perceptual Investigation into Spatialization Techniques Used in Multichannel Electroacoustic Music for Envelopment and Engulfment

© 2017 Massachusetts Institute of Technology. Composers of electroacoustic music have developed and creatively implemented various spatialization techniques for multichannel loudspeaker setups. What is not known is which of these spatialization techniques is most effective for exploiting the extended creative possibilities available in multidimensional sound. This article discusses an experiment investigating the perception of the spatial attributes of "envelopment" and "engulfment" within a high-density loudspeaker array. The spatialization techniques used in the experiment were timbre spatialization, spectral splitting, amplitude point-source panning, and dynamic spectral subband decorrelation. Three loudspeaker setups, or spatial dimensions, were investigated: horizontal-only; elevated-only; and three-dimensional, which consisted of both horizontal and elevated loudspeaker setups. Results suggest that dynamic spectral subband decorrelation was perceived as both the most enveloping and the most engulfing technique when compared to other techniques in these experimental loudspeaker configurations. We propose that the experimental results can be successfully implemented when composing electroacoustic music to exploit the creative possibilities in a high-density loudspeaker array or in other multichannel loudspeaker configurations

Improving green manure quality with phosphate rocks in Ontario Canada

Phosphate rock (PR) was applied to one conventional and two organic dairy fields and planted with buckwheat (Fagopyrum esculentum) as a green manure crop. In total, five types of PR were applied at three application rates in order to determine the yield, concentration of P in the aboveground tissue and the P uptake of buckwheat. It was found that PR of relatively high carbonate substitution and small particle diameter could increase buckwheat tissue concentrations to a quality such that mineralization of the buckwheat mulch could occur. Buckwheat mulch and residual PR increased soil P flux as determined by anion exchange membranes in situ in the following spring. This provides evidence that buckwheat of high P quality has the potential to supply P to a subsequent crop

Adaptive evolution of molecular phenotypes

Molecular phenotypes link genomic information with organismic functions, fitness, and evolution. Quantitative traits are complex phenotypes that depend on multiple genomic loci. In this paper, we study the adaptive evolution of a quantitative trait under time-dependent selection, which arises from environmental changes or through fitness interactions with other co-evolving phenotypes. We analyze a model of trait evolution under mutations and genetic drift in a single-peak fitness seascape. The fitness peak performs a constrained random walk in the trait amplitude, which determines the time-dependent trait optimum in a given population. We derive analytical expressions for the distribution of the time-dependent trait divergence between populations and of the trait diversity within populations. Based on this solution, we develop a method to infer adaptive evolution of quantitative traits. Specifically, we show that the ratio of the average trait divergence and the diversity is a universal function of evolutionary time, which predicts the stabilizing strength and the driving rate of the fitness seascape. From an information-theoretic point of view, this function measures the macro-evolutionary entropy in a population ensemble, which determines the predictability of the evolutionary process. Our solution also quantifies two key characteristics of adapting populations: the cumulative fitness flux, which measures the total amount of adaptation, and the adaptive load, which is the fitness cost due to a population's lag behind the fitness peak.Comment: Figures are not optimally displayed in Firefo

Investigation of mixed element hybrid grid-based CFD methods for rotorcraft flow analysis

Accurate first-principles flow prediction is essential to the design and development of rotorcraft, and while current numerical analysis tools can, in theory, model the complete flow field, in practice the accuracy of these tools is limited by various inherent numerical deficiencies. An approach that combines the first-principles physical modeling capability of CFD schemes with the vortex preservation capabilities of Lagrangian vortex methods has been developed recently that controls the numerical diffusion of the rotor wake in a grid-based solver by employing a vorticity-velocity, rather than primitive variable, formulation. Coupling strategies, including variable exchange protocols are evaluated using several unstructured, structured, and Cartesian-grid Reynolds Averaged Navier-Stokes (RANS)/Euler CFD solvers. Results obtained with the hybrid grid-based solvers illustrate the capability of this hybrid method to resolve vortex-dominated flow fields with lower cell counts than pure RANS/Euler methods