The effects of alcohol on driver performance in a decision making situation

The results are reviewed of driving simulator and in-vehicle field test experiments of alcohol effects on driver risk taking. The objective was to investigate changes in risk taking under alcoholic intoxication and relate these changes to effects on traffic safety. The experiments involved complex 15 minute driving scenarios requiring decision making and steering and speed control throughout a series of typical driving situations. Monetary rewards and penalties were employed to simulate the real-world motivations inherent in driving. A full placebo experimental design was employed, and measures related to traffic safety, driver/vehicle performance and driver behavior were obtained. Alcohol impairment was found to increase the rate of accidents and speeding tickets. Behavioral measures showed these traffic safety effects to be due to impaired psychomotor performance and perceptual distortions. Subjective estimates of risk failed to show any change in the driver's willingness to take risks when intoxicated

A Study of the Degradation of Electronic Speed Controllers for Brushless DC Motors

Brushless DC motors are frequently used in electric aircraft and other direct drive applications. As these motors are notactually direct current machines but synchronous alternating current machines; they are electronically commutated by a power inverter. The power inverter for brushless DC motors typically used in small scale UAVs is a semiconductor base delectronic commutator that is external to the motor and is referred to as an electronic speed control (ESC). This paper examines the performance changes of a UAV electric propulsion system resulting from ESC degradation. ESC performance is evaluated in simulation and on a new developed test bed featuring propulsion components from a reference UAV. An increase in the rise fall times of the switched voltages is expected to cause timing issues at high motor speeds. This study paves the way for further development of diagnostic and prognostic methods for inverter circuits which are part of the overall electric UAV system

Effects of a seaweed extract on weanling pig growth performance and immune function during an acute enteric disease challenge

A total of 95 pigs (initially 15 lb and 17 d of age) was used in a 28 d growth trial to determine the effects of Ascophyllum nodosum seaweed extract (ANOD) on weanling pig growth performance and immune function in response to enteric disease challenge with Salmonella typhimurium (ST). Experimental treatments were arranged in a 2 x 4 factorial with main effects of disease challenge (control vs. ST challenge) and dietary addition of ANOD (0, 0.5, 1.0, and 2.0% of diet). Results suggest little beneficial effect of dietary ANOD on growth performance or immune response in the presence or absence of ST challenge

Theoretical Investigation of Iterative Phase Retrieval Algorithm for Quasi-Optical Millimeter-Wave RF Beams

In this paper, we present a detailed analysis of the iterative phase retrieval approach (TPRA) for determining the phase profile of the output microwave beam of a gyrotron from known intensity patterns emphasizing the field propagation techniques which are used to propagate the RF field of the microwave beam between known intensity planes. The propagation method, based on first Rayleigh-Sommerfeld diffraction integral (RSDI), is solved using fast Fourier transform (FFT) technique and zero padding. It is observed that the use of FFT and, therefore, the discretization of the RSDI propagation kernel introduce aberrations in the propagated field due to the superposition of the original field with its replicated versions. This problem is solved by approximations leading to the Huygens-Fresnel propagation method which further Imposes the restrictions on the distances of propagation depending on the size of the transverse plane used to discretize the intensity pattern. This constraint of the distance of propagation causes problem in the iterative phase retrieval approach (IPRA) when more than two intensity planes are used. A method based on interpolation is proposed to overcome this restriction. IPRA is then further discussed to optimize several parameters, such as plane separation, plane dimension, mesh size, and measurement accuracies, which become more of an issue during the measurements of infrared Intensity thermograms of the output microwave beam

Effects of a quillaja saponaria extract on weanling pig growth performance and immune function during an acute enteric disease challenge

A total of 96 pigs (initially 19 lb and 17 d of age) was used in a 28 d growth trial to determine the effects of Quillaja saponaria (QS) extract on weanling pig growth performance and immune function in response to enteric disease challenge with Salmonella typhimurium (ST). Experimental treatments were arranged in a 2 × 4 factorial with main effects of disease challenge (control vs. ST challenge) and dietary addition of QS (0, 4, 8, or 16 oz/ton). The results suggest little beneficial effect of QS on growth performance or immune response in the presence or absence of ST challenge

Multimode calculation of frequency tunable gyrotrons for dynamic nuclear polarization applications

Multimode calculations of a low-power (above 10W) high-frequency (200 GHz -300 GHz) gyrotron for NMR (nuclear magnetic resonance) spectroscopy applications have been performed. Six transverse modes (TE-7, 2; TE7, 2; TE-4, 3; TE4, 3; TE-2, 4; TE2, 4) whose coupling factors are above 30% and most probably excited in the cavity were included into the calculation. The frequency fine tuning was obtained via the excitation of a sequence of longitudinal modes of TE-7, 2, q by varying the beam voltage from 15kV upward and the magnetic field from 9.6T to 9.77T. The diffractive quality factor of the cavity equals to 9965 and the ohmic quality factor of the cavity equals to 6414. The results show that the main mode TE-7, 2 is quite stable against the possible transverse mode competitors within this magnetic field range and a continuous frequency tuning range more than 800MHz (263.43 GHz - 264.28 GHz) has been achieved with alpha equaling 1.3, the beam radius and current being 1.33 and 100mA respectively

Infrared Measurements of the RF Output of 170-GHz/2-MW Coaxial Cavity Gyrotron and Its Phase Retrieval Analysis

We report the experimental results of the infrared measurements of output RF beam of the European 2-MW 170-GHz coaxial cavity gyrotron for ITER. The output beam profile is measured by the infrared thermographic technique using an infrared camera and a target material which is being irradiated by the RF output. The beam intensity was measured at several locations along the propagation direction. The data were processed for noise reduction and perspective correction and then used with the phase retrieval algorithm to yield an accurate estimate of the phase profile. The moments of the measured intensity arrays are calculated to improve the reliability of the measured infrared image data and data processing. The beam profile is also measured at specific locations in order to compare the phase calculated with the HuygensFresnel propagation method for fixed distance and RayleighSommerfeld diffraction integral method used for field propagation in the phase retrieval algorithm