George Rutherford
Illinois State University
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Publication
Featured researches published by George Rutherford.
Optics Letters | 2007
S. D. Campbell; O'connell Ak; George Rutherford; R. Grobe
We discuss the impact of large-angle scattering events in highly forward-scattering media on the spatial distribution of the diffusively reflected light. We show that, even for highly forward-scattering media, the reflected light near the incident beam axis is strongly dependent on the small number of large-angle scattering events. Reliable modeling of near-axis reflection thus requires accurate knowledge of the scattering phase functions behavior at large angles.
Laser Physics | 2007
S. D. Campbell; S. Menon; George Rutherford; Q. Su; R. Grobe
We inject a laser beam into a tank filled with a milk-water emulsion and measure the intensity distribution of the scattered light. As we change the concentration of the milk, we observe a nontrivial change in the light intensity as a function of the detector position. We analyze the light on and parallel to the input beam direction, as well as the scattered light in the transverse direction. The nonmonotonic scaling of the intensity as a function of the concentration and the position is also predicted by Monte Carlo simulations. With a doubling of the concentration, the detected light along the optical axis decreases globally, whereas the reflected light decreases or increases depending on the location of the detector.
Journal of Physics A | 1998
George Rutherford; R. Grobe
We investigate the dynamics of electrons of opposite spin in an inhomogeneous but unidirectional magnetic field. We compare the quantum expectation values of wavefunctions obtained from the Dirac equation with the averages of classical ensembles. Both confirm our analytical predictions for a parameter regime in which the electrons are separated but have partially spatially overlapping probabilities.
Chaos | 2018
Rosangela Follmann; Annabelle Shaffer; Zachary Mobille; George Rutherford; Epaminondas Rosa
We study a heterogeneous neuronal network motif where a central node (hub neuron) is connected via electrical synapses to other nodes (peripheral neurons). Our numerical simulations show that the networked neurons synchronize in three different states: (i) robust tonic, (ii) robust bursting, and (iii) tonic initially evolving to bursting through a period-doubling cascade and chaos transition. This third case displays interesting features, including the carrying on of a characteristic firing rate found in the single neuron tonic-to-bursting transition.
Journal of Occupational and Environmental Hygiene | 2017
George Byrns; Beverly J. Barham; Liangcheng Yang; Kathryn Webster; George Rutherford; Garrett Steiner; Daniel Petras; Michele Scannell
ABSTRACT The morbidity and mortality from healthcare associated infections has raised concern that conventional disinfection methods are inadequate and that other adjunct methods such as room fumigation and ultraviolet irradiation may be needed. There is also concern that these alternative methods may pose a risk to workers and patients. Objectives. (1) Determine the efficacy of a germicidal UV-C wand for surface disinfection, (2) evaluate changing relative humidity (RH) and different target distances on bacteria kill rates, and (3) assess potential exposure concerns. Methods. This study investigates whether a hand-held germicidal wand can efficaciously disinfect surfaces treated with either a vegetative or spore forming bacterium and to evaluate the effect of changing environmental conditions such as relative humidity (RH), target position, and target distances on microbial kill rates. Results. Kill rate was best at 40–65% RH at a temperature range of 21–24°C. Both high and low RH interfered with the ability of UV-C to kill the vegetative microbe. In the case of the spore forming bacterium, increased surface drying time was the most significant factor increasing kill rate. Conclusions. This research demonstrates that UV-C was efficacious under optimal conditions, a direct beam exposure, and a short target distance (12.7 cm). However, there are limitations when used in non-optimal conditions. Increased distance and indirect beam angles resulted in lower kill rates. It is also important to minimize unnecessary patient and worker exposure during its use.
Review of Scientific Instruments | 2016
Nathan Clayburn; Evan Brunkow; Samantha Burtwistle; George Rutherford
A small, novel, cylindrically symmetric Mott electron polarimeter is described. The effective Sherman function, Seff, or analyzing power, for 20 kV Au target bias with a 1.3 keV energy loss window is 0.16 ± 0.01, where uncertainty in the measurement is due primarily to uncertainty in the incident electron polarization. For an energy loss window of 0.5 keV, Seff reaches its maximum value of 0.24 ± 0.02. The devices maximum efficiency, I/Io, defined as the detected count rate divided by the incident particle rate, is 3.7 ± 0.2 × 10(-4) at 20 keV. The figure-of-merit of the device, η, is defined as Seff (2)IIo and equals 9.0 ± 1.6 × 10(-6). Potential sources of false asymmetries due to detector electronic asymmetry and beam misalignment have been investigated. The new polarimeters performance is compared to published results for similar compact retarding-field Mott polarimeters, and it is concluded that this device has a relatively large Seff and low efficiency. SIMION(®) electron trajectory simulations and Sherman function calculations are presented to explain the differences in performance between this device and previous designs. This design has an Seff that is insensitive to spatial beam fluctuations and, for an energy loss window >0.5 keV, negligible background due to spurious ion and X-ray production at the target.
Laser Physics | 2006
George Rutherford; M. Narter; S. Menon; Q. Su; R. Grobe
We describe the formation of a narrow beam for intensity-modulated electromagnetic radiation propagating through highly scattering materials. We propose to use this beam to reconstruct images, similar to X-ray back-projection techniques. For sufficiently high modulation frequency, the photon density wave is primarily carried by photons that suffer small or no large-angle scattering, which gives rise to the beam’s narrow divergence. The beam-narrowing concept is supported by large-scale numerical simulations to examine the quality of the imaging.
Physical Review A | 1992
George Rutherford; Soletsky Pa; Bryan Wh; F. B. Dunning; G. K. Walters
Physical Review A | 1989
J. M. Ratliff; George Rutherford; F. B. Dunning; G. K. Walters
Bulletin of the American Physical Society | 2015
Nathan Clayburn; Evan Brunkow; George Rutherford; Samantha Burtwistle