Comparison of Raman, NIR, and ATR FTIR spectroscopy as analytical tools for in-line monitoring of CO2 concentration in an amine gas treating process

Chemical absorption of CO2 using aqueous amine-based solvents is one of the common approaches to control acidic gases emissions to the atmosphere. Improvement in the efficiency of industrial processes requires precise monitoring tools that fit with the specific application. Process monitoring using in-line multivariate measurement methods...

Prediction of Optimal Salinities for Surfactant Formulations Using a Quantitative Structure-Property Relationships Approach

Each oil reservoir could be characterized by a set of parameters such as temperature, pressure, oil composition, and brine salinity, etc. In the context of the chemical enhanced oil recovery (EOR), the selection of high performance surfactants is a challenging and time-consuming task since this strongly depends on the reservoir's conditions. The...

Least-Squares Estimation of Imaging Parameters for an Ultrasonic Array Using Known Geometric Image Features

Ultrasonic array images are adversely affected by errors in the assumed or measured imaging parameters. For non-destructive testing and evaluation, this can result in reduced defect detection and characterization performance. In this paper, an autofocus algorithm is presented for estimating and correcting imaging parameter errors using the...

A multivariate correlation analysis of high-frequency bottom backscattering strength measurements with geotechnical parameters

Sound backscattered from the seabed has been measured in a 10 × 10-nmi2 region of the North Sea, characterized by a variety of bottom types, including mud, sand, and gravel. The backscattering strength measurements are made by a forward-looking sonar, operating at 100 kHz and tilted at an angle of 30° from the horizontal. Fifty bottom-grab...

Detection and localisation of magnetic objects

Detection and localisation of hidden magnetic objects is studied. The concomitant disturbance of the earth magnetic field is exploited. Magnetic fields and or gradients are measured with a number of sensors. Two point models for magnetic fields are selected for the analysis: the magnetic dipole and its quadrupole extension. It is shown how to...

Sign constraints improve the detection of differences between complex spectral data sets: LC-IR as an example

Spectroscopy is a fast and rich analytical tool. On many occasions, spectra are acquired of two or more sets of samples that differ only slightly. These data sets then need to be compared and analyzed, but sometimes it is difficult to find the differences. We present a simple and effective method that detects and extracts new spectral features...

Robust spectral factor approximation of discrete-time frequency domain power spectras

This paper presents a subspace-based identification algorithm for estimating the state-space quadruple [A,B,C,D] of a minimum-phase spectral factor from matrix-valued power spectrum data. For a given pair [A,C] with A stable, the minimum-phase property is guaranteed via the solution of a conic linear programming (CLP) problem. In comparison with...

A Two-Stage Method for Determining the Position and Corresponding Precision of Marine Mammal Sounds; 2004BU1-OT

Today there is a concern that man-made sounds, such as that from sonar experiments, seismic operations and oil rigs, affect marine mammals. Detection and localisation of marine mammals will definitely support measures to reduce the possible detrimental effects. This paper presents a two-stage localisation method, which is applied to data...

Absorption of the eye lens and macular pigment derived from the reflectance of cone photoreceptors

We measured the amplitude of the directional component of the bleached fundus reflectance, the so-called optical Stiles-Crawford effect, as a function of wavelength. The directional reflectance originates from within the outer segments of the photoreceptors. Thus only two anterior absorbers are of importance: Macular pigment and the crystalline...

Powers synthesis of array antennas using the continuation method on far field phase distribution

We present a technique, based on the continuation method, to face power synthesis problems for array antennas. By using the least squares method (LSM), the power synthesis problem reduces to the minimization of an objective functional, which represents the square of the distance between the required and actual complex radiation pattern....

Shallow-water acoustic communication with high bit rate BPSK signals

BPSK signals have been defined for transmission through a shallow-water acoustic communication channel. The signals were accompanied by two displaced carriers to facilitate carrier recovery. To correct for the adverse effects of time spreading, a pseudo-random learning sequence was transmitted ahead of the communication signal. The signal...

Guidelines for accurate TOD measurement

The Triangle Orientation Discrimination (TOD) threshold is an alternative method to characterize electro-optical system performance. The method is based on an improved test pattern, a better-defined observer task and a solid psychophysical measurement procedure, and allows accurate and comparable results from different measuring teams. With the...