Top transport in electroweak baryogenesis

In non-supersymmetric models of electroweak baryogenesis the top quark plays a crucial role. Its CP-violating source term can be calculated in the WKB approximation. We point out how to resolve certain discrepancies between computations starting from the Dirac equation and the Schwinger--Keldysh formalism. We also improve on the transport equations, keeping the W-scatterings at finite rate. We apply these results to a model with one Higgs doublet, augmented by dimension-6 operators, where our refinements lead to an increase in the baryon asymmetry by a factor of up to about 5.Comment: 17 pages, 3 figures, references adde

EFFECT OF DIFFERENT LOW BACK TRAINING PROGRAMS ON LUMBAR SPINE KINESTHESIA

Reduced kinesthetic perceptions can impair lower back sensorimotor functions and result in increased injury risk. The effect of low back training programs on lumbar spine kinesthetic sensibility is undetermined. There was a back strengthening exercise group (with low back pain; training 4.4 h/wk), a “classical” back training program group (with low back pain; training 4.9 h/wk) and a control group (training 5.4 h/wk). During an active reproduction test, subjects performed trunk positions in random order: flexion [A(0°-20°), B(20°-40°)], lateral flexion [C(0°-30°)], Using a 3D-ultrasound motion analysis system the repositioning error was calculated from the given target position to the subject perceived target position, before and after a 5 week training period. Results show decreased repositioning error after the training for both training groups

VITESS 3 Virtual Instrumentation Tool for the European Spallation Source

VITESS is a software widely used for simulation of neutron scattering experiments. Although originally motivated by instrument design for the European Spallation Source, all major neutron sources are available. Existing as well as future instruments on reactor or spallation sources can be designed and optimized, or simulated in a virtual experiment to prepare a measurement, including basic data evaluation. This note gives an overview of the VITESS software concept and usage. New developments are presented, including a 3D visualization of instruments and neutron trajectories, a numerical optimization routine and a parallelization tool allowing to split VITESS simulations on a computer cluste

Identification of aerodynamic damping matrix for operating wind turbines

© 2020 Elsevier Ltd Accurate knowledge of wind turbine tower vibration damping is essential for the estimation of fatigue life. However, the responses in the fore-aft and side-side directions are coupled through the wind-rotor interaction under operational conditions. This causes energy transfers and complicates aerodynamic damping identification using conventional damping ratios. Employing a reduced two-degree of freedom wind turbine model developed in this paper, this coupling can be accurately expressed by an unconventional aerodynamic damping matrix. Simulated time series obtained from this model were successfully verified against the outputs from the wind turbine simulation tool FAST. Based on the reduced system obtained, a matrix-based identification method is proposed to identify the aerodynamic damping for numerically simulated wind turbine tower responses. Applying harmonic excitations to the tower allowed the frequency response functions of the wind turbine system to be obtained and the aerodynamic damping matrix to be extracted. Results from this identification were compared to traditional operational modal analysis methods including standard and modified stochastic subspace identification. The damping in the fore-aft direction was successfully identified by all methods, but results showed that the identified damping matrix performs better in capturing the aerodynamic damping and coupling for the side-side responses

Dose, exposure time, and resolution in Serial X-ray Crystallography

The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density map in the projection approximation. These calculations include counting shot noise and multiple starts of the phasing algorithm. The results indicate counting time and the number of proteins needed within the beam at any instant for a given resolution and X-ray flux. We confirm an inverse fourth power dependence of exposure time on resolution, with important implications for all coherent X-ray imaging. We find that multiple single-file protein beams will be needed for sub-nanometer resolution on current third generation synchrotrons, but not on fourth generation designs, where reconstruction of secondary protein structure at a resolution of 0.7 nm should be possible with short exposures.Comment: 19 pages, 7 figures, 1 tabl

Trends in opioid use over time: 1997 to 1999

Substantial resources have been spent to improve pain control for dying patients, and increased opioid administration has been presumed. Oregon has been a consistent leading state in per capita use for morphine for the past 10 years, as recorded by the Automation of Reports and Consolidated Orders System (ARCOS). Health policy experts, extrapolating from World Health Organization methods, have suggested these data are indicative of the quality of end-of-life care in Oregon. To determine whether trends in opioid prescription at the state and national levels reflect increased opioid use for inpatients during the final week of life, chart reviews were conducted to record all opioid medications administered in the last week of life to 877 adult inpatients who died from natural causes between January 1, 1997 and December 31, 1999. Inpatient morphine use did not increase significantly for dying patients from 1997 to 1999. However, overall morphine use for both Oregon and the United States as measured by ARCOS data increased significantly. Comparisons revealed no significant difference between linear trends for Oregon and U.S. morphine use, but both were significantly greater than the dying inpatients. This pattern was also found for all other opioids. These findings suggest that ARCOS data do not necessarily provide information about opioid use for specific subpopulations of patients and raise questions about the meaning of observed increases in ARCOS data

Modally selective nonlinear ultrasonic waves for characterization of pitting damage in whipple shields of spacecraft

Featuring hundreds of craters, cracks and diverse microscopic defects disorderedly scattered over a wide region, the pitting damage in a typical Whipple shield of spacecraft induces highly complex wave scattering. Due to the dispersive and multimode natures, only nonlinear ultrasonic waves (NUWs) with exact phase-velocity matching condition are generally used to evaluate the microstructural material deterioration. Targeting accurate, holistic evaluation of pitting damage, semi-analytical finite element (SAFE) approach is adopted to identify the internal resonant conditions and to select an efficient mode pair for characterizing pitting damage. To explore the feasibility of pitting damage evaluation by using the selected mode pair and fully utilize its unique merits, the cumulative effect of second harmonics is analyzed using numerical simulations and corroborated by experiment. Regardless of the selection of mode pair (i.e., S1-s2 and S0-s0), the amplitude of second harmonics obtained in the pitted plate is observed to increase significantly after the probing GUWs traverse the pitted region, upon interacting with the pitting damage. This phenomenon is remarkable particularly when the probing GUW does not satisfy the requirement of internal resonance. The mode pairs S0-s0 with different degrees of phase-velocity mismatching are further analyzed. Results show that the hypervelocity impact-induced pitting damage in the rear wall of Whipple shields can be detected accurately using the mode pair S0-s0, and a relatively higher excitation frequency is preferred due to its higher degree of phase-velocity mismatching, leading to standing out of the pitting damage-induced CAN

Nonlinear ultrasonic evaluation of disorderedly clustered pitting damage using an in situ sensor network

Pervasive but insidious, pitting damage—from pitting corrosion in maritime structures through electrical pitting in bearings to debris cloud–induced pitting craters in spacecraft—is a typical modality of material degradation and lesion in engineering assets in harsh service environment. Pitting damage may feature hundreds of clustered, localized craters, cracks, and diverse microscopic defects (e.g. dislocation, micro-voids, and cracks) disorderedly scattered over a wide area. Targeting accurate, holistic evaluation of pitting damage (mainly the existence, location, and size of the pitted area), an insight into the generation of nonlinear features in guided ultrasonic waves (i.e. high-order harmonics) that are triggered by pitting damage, is achieved using a semi-analytical finite element approach, based on which a monotonic correlation between the nonlinear ultrasonic features and the holistic severity of pitting damage is established. With such correlation, a structural health monitoring framework is developed, in conjunction with the use of an in situ sensor network comprising miniaturized piezoelectric wafers, to characterize pitting damage accurately and monitor material deterioration progress continuously. The framework is experimentally validated, in which highly complex pitting damage in a space structure, engendered by a hypervelocity debris cloud, is evaluated precisely