Experimental study of cross flow mixing in cylindrical and rectangular ducts

An experimental investigation of non-reacting cross flow jet injection and mixing in cylindrical and rectangular ducts has been conducted with application to a low emissions combustor. Quantitative measurement of injectant concentration distributions perpendicular to the duct axis were obtained by planar digital imaging of the Mie-scattered light from an aerosol seed mixed with the injectant. The flowfield unmixedness was evaluated using (1) a mixing parameter derived from the ratio of the jet concentration fluctuations to the fully mixed concentration, and (2) probability density functions of the concentration distributions. Mixing rate was measured for 45 degree slant slot and round orifice injectors

Testing Higgs models via the H±W∓ZH^\pm W^\mp Z vertex by a recoil method at the International Linear Collider

In general, charged Higgs bosons $H^\pm$ appear in non-minimal Higgs models. The $H^\pm W^\mp Z$ vertex is known to be related to the violation of the global symmetry (custodial symmetry) in the Higgs sector. Its magnitude strongly depends on the structure of the exotic Higgs models which contain higher isospin $SU(2)_L$ representations such as triplet Higgs bosons. We study the possibility of measuring the $H^\pm W^\mp Z$ vertex via single charged Higgs boson production associated with the $W^\pm$ boson at the International Linear Collider (ILC) by using the recoil method. The feasibility of the signal $e^+e^-\to H^\pm W^\mp \to \ell \nu jj$ is analyzed assuming the polarized electron and positron beams and the expected detector performance for the resolution of the two-jet system at the ILC. The background events can be reduced to a considerable extent by imposing the kinematic cuts even if we take into account the initial state radiation. For a relatively light charged Higgs boson whose mass $m_{H^\pm}$ is in the region of 120-130 GeV $< m_{H^\pm} < m_W+m_Z$, the $H^\pm W^\mp Z$ vertex would be precisely testable especially when the decay of $H^\pm$ is lepton specific. The exoticness of the extended Higgs sector can be explored by using combined information for this vertex and the rho parameter.Comment: 22 pages, 23 figure

Functionality of the LEP tune meters with 3rd generation DSPs

The LEP tune meters have been upgraded by replacing the original Motorola 68020 processor cards by Texas Instruments TSM320C30 Digital Signal Processor cards with floating point arithmetic and by creating an optional connection to a more sensitive beam position monitor. This upgrade has lead to a considerable increase in speed and accuracy. The new instrument can generate a continuous real time display of the beam motion in the frequency domain which is well suited to monitor dynamic phenomena occurring during injection and acceleration of the LEP collider. The dynamic phenomena can also be stored for off line analysis. The paper describes the functionality of the instrument in terms of user interface and covers some aspects of code debugging and process synchronization for DSP's connected to the standard control system of an accelerator

Real-Time Monitoring of Beam-Beam Modes at LEP

By slightly exciting one of two colliding bunches in LEP, it is possible to enhance the eigenfrequencies of the resonant system of the two bunches coupled by the space charge force. The LEP Qmeter has been adapted to detect, among these excited frequencies, the so called s- and p- modes, whose distance is proportional to the luminosity. A real time display of these quantities provides the Operators with an effective way of finely optimizing the luminosity

Fourier transforming a trapped Bose-Einstein condensate by waiting a quarter of the trap period: simulation and applications

We investigate the property of isotropic harmonic traps to Fourier transform a weakly interacting Bose–Einstein condensate (BEC) every quarter of a trap period. We solve the Gross–Pitaevskii equation numerically to investigate the time evolution of interacting BECs in the context of the Fourier transform, and we suggest potential applications

Niacin-induced clotting factor synthesis deficiency with coagulopathy

Although coagulopathy is a well-known complication of severe niacin- induced hepatotoxic reaction, it is not found in patients with minimal aminotransferase level elevations. Three patients with significant clotting factor synthesis deficiency and coagulopathy (prothrombin times, >1.5 times control) from sustained-release niacin had only mild aminotransferase level elevations (1.5 to 2.0 times normal). In each case, protein deficiency, coagulopathy, and aminotransferase level elevation resolved promptly after withdrawal of niacin therapy. In one case, this syndrome recurred after rechallenge with sustained-release niacin, whereas the coagulopathy did not recur in a second patient rechallenged with crystalline niacin. Deficiency in protein synthesis, including coagulation factors, and coagulopathy are unrecognized complications of sustained-release niacin therapy. These cases indicate the need to measure prothrombin times routinely in patients who develop even mild aminotransferase level elevation while receiving sustained- release niacin therapy. These data are important in light of the increasing use of sustained-release niacin in the treatment of patients with lipid disorders

Reinforcement-Driven Spread of Innovations and Fads

We propose kinetic models for the spread of permanent innovations and transient fads by the mechanism of social reinforcement. Each individual can be in one of M+1 states of awareness 0,1,2,...,M, with state M corresponding to adopting an innovation. An individual with awareness k<M increases to k+1 by interacting with an adopter. Starting with a single adopter, the time for an initially unaware population of size N to adopt a permanent innovation grows as ln(N) for M=1, and as N^{1-1/M} for M>1. The fraction of the population that remains clueless about a transient fad after it has come and gone changes discontinuously as a function of the fad abandonment rate lambda for M>1. The fad dies out completely in a time that varies non-monotonically with lambda.Comment: 4 pages, 2 columns, 5 figures, revtex 4-1 format; revised version has been expanded and put into iop format, with one figure adde

Identification problems of muon and electron events in the Super-Kamiokande detector

In the measurement of atmospheric nu_e and nu_mu fluxes, the calculations of the Super Kamiokande group for the distinction between muon-like and electronlike events observed in the water Cerenkov detector have initially assumed a misidentification probability of less than 1 % and later 2 % for the sub-GeV range. In the multi-GeV range, they compared only the observed behaviors of ring patterns of muon and electron events, and claimed a 3 % mis-identification. However, the expressions and the calculation method do not include the fluctuation properties due to the stochastic nature of the processes which determine the expected number of photoelectrons (p.e.) produced by muons and electrons. Our full Monte Carlo (MC) simulations including the fluctuations of photoelectron production show that the total mis-identification rate for electrons and muons should be larger than or equal to 20 % for sub-GeV region. Even in the multi-GeV region we expect a mis-identification rate of several % based on our MC simulations taking into account the ring patterns. The mis-identified events are mostly of muonic origin.Comment: 17 pages, 12 figure