We compare a nonlinear upconversion detector with a conventional cryogenic InSb detector for the detection of coherent infrared light showing near-shot-noise-limited performance in the upconversion system. The InSb detector is limited by dark noise, which results in a 500 times lower signal-to-noise ratio. The two detectors are compared for the detection of a coherent degenerate four-wave mixin...

The ability to obtain laser based quantitative temperature measurements is particularly important in high pressure environments. In this study, quantitative temperature measurements using Laser Induced Thermal Grating Spectroscopy (LITGS) were employed for a toluene vapor/air jet varying the toluene concentration and pump laser power. In LITGS, the gas temperature at the crossing point of two p...

The sea surface imprints of Atmospheric Vortex Street (AVS) off Aleutian Volcanic Islands, Alaska were observed in two RADARSAT-1 Synthetic Aperture Radar (SAR) images separated by about 11 hours. In both images, three pairs of distinctive vortices shedding in the lee side of two volcanic mountains can be clearly seen. The length and width of the vortex street are about 60-70 km and 20 km, resp...

Ion mobility spectrometry (IMS) was first introduced in the late 1960s as an instrumental technique for the detection of trace quantities of gaseous organic compounds at atmospheric pressure. The development of mobility theory and the emerging analytical applications for IMS were later discussed by FW Karasek [1] and researchers continued to gather fundamental data about this technique and the ...

LOW-TEMPERATURE CARBURIZATION is a gaseous carburization process performed at atmospheric pressure, at temperatures where the kinetics of substitutional diffusion are very slow. Low-temperature carburization hardens the surface of austenitic stainless steels through the diffusion of interstitial carbon, without the formation of carbides. The surface must be activated, by modification and remova...

Free uroporphyrin is decarboxylated by heating in the air to 150--200 degrees C. Complete decarboxylation occurs after heating to 200 degrees C for 5 min, with a yield of 66--75%. Heptacarboxylic porphyrin can be prepared with a yield of 40% by heating uroporphyrin to 150 degrees C for 60 min, and hexacarboxylic porphyrin with a yield of about 20% by heating to 150 degrees C for 2h.

Joint beam width and spatial coherence length optimization is proposed to maximize the average capacity in partially coherent free-space optical links, under the combined effects of atmospheric turbulence and pointing errors. An optimization metric is introduced to enable feasible translation of the joint optimal transmitter beam parameters into an analogous level of divergence of the received ...

As part of a combined experimental and theoretical study of the thermodynamic properties of perfluoroalkylalkanes (PFAAs), the liquid density of perfluorobutylpentane (F4H5), perfluorobutylhexane (F4H6), and perfluorobutyloctane (F4H8) was measured as a function of temperature from 278.15 to 353.15 K and from atmospheric pressure to 70 MPa. The liquid densities of n-perfluoropentane, n-perfluor...

In this paper, the progress in the theoretical study of the dielectric barrier discharge is reported. The model of the atmospheric-pressure discharge is discussed. Such effects as the oscillations of the Townsend mode of the discharge, the instability of the Townsend mode with subsequent transition to the filamentary discharge, and the stabilization of the barrier discharge by the photoemission...

The wavelet variance provides a scale-based decomposition of the process variance for a time series or a random field and has been used to analyze various multi-scale processes. Examples of such processes include atmospheric pressure, deviations in time as kept by atomic clocks, soil properties in agricultural plots, snow fields in the polar regions and brightness temperature maps of South Paci...