The mass composition of high energy cosmic rays depends on their production, acceleration, and propagation. The study of cosmic ray composition can therefore reveal hints of the origin of these ...particles. At the South Pole, the IceCube Neutrino Observatory is capable of measuring two components of cosmic ray air showers in coincidence: the electromagnetic component at high altitude (2835 m) using the IceTop surface array, and the muonic component above similar to 1 TeV using the IceCube array. This unique detector arrangement provides an opportunity for precision measurements of the cosmic ray energy spectrum and composition in the region of the knee and beyond. We present the results of a neural network analysis technique to study the cosmic ray composition and the energy spectrum from 1 PeV to 30 PeV using data recorded using the 40-string/40-station configuration of the IceCube Neutrino Observatory.
Copper corrosion, tarnishing, release and color stability were investigated in a series of candidate antimicrobial copper alloys Cu, Cu–5Sn, Cu–5Zn–5Al–1Sn, Cu–10Ni–1.5Fe–1Zn, Cu–18Ni–17Zn–1Mn, ...Cu–20Zn–3Si, and Cu–30Zn (wt% indicated). High Cu content, often utilized as an indicator of antimicrobial efficacy brought about by copper release, is shown to be insufficient alone to forecast Cu ion release tendencies during exposure. Alloys were exposed under full immersion in a standardized artificial perspiration solution. Copper release, relative film thickness, the molecular identity of the tarnish, and optical wavelength reflectivity were assessed to determine the fate of copper during oxidation. Copper release did not generally correlate with bulk Cu alloy content, tarnish thickness, or overall corrosion rate due to the unique effects of both major and minor alloying elements. Mechanisms for high or low corrosion rates, tarnishing and Cu release as a function of alloying content are discussed.
To validate a Monte Carlo simulation of light propagation in the finger tip, reference transmission and pulsation spectra are required. To obtain them, the following method is applied: A fingertip is ...illuminated by halogen light, and the light that passes the fingertip is recorded by a spectrometer. By comparing a reference spectrum of the light source and the transmitted spectrum, the static transmission spectrum is calculated. Furthermore, from the variation of the transmitted light spectrum in time, a pulsation amplitude spectrum is deduced which contains the change of transmission due to the pulsation of arterial blood. This spectrum resembles the in-vitro spectrum of the effective attenuation coefficient of arterial blood. In a wavelength range from 600 nm to 1300 nm, the methods described in this paper have shown to produce spectra which are suitable to serve as reference for the Monte Carlo simulation.
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