Layered blind deconvolution using subband filter banks

A blind deconvolution method using the concept of subband filter banks has been proposed. This method makes possible the speedy convergence of solution, due to estimation of supports of the reconstructed images by a deconvolution in the lower layer. We apply the method to blind deconvolution by a simulated annealing algorithm and confirm its usefulness. Presented at 1996 International Topical Meeting on Optical Computing (OC’96), April 21–25, Sendai, Japan.     

Fourier transform spectrometer instrument lineshape (ILS) retrieval by Fourier deconvolution

This work presents a Fourier deconvolution (FD) technique for retrieving the instrument lineshape (ILS) function of high-resolution Fourier transform infrared (FTIR) spectrometers. The ILS retrieved by FD is compared with the results obtained using the LINEFIT technique of Hase. The effect of a non-ideal ILS function on quantitative analysis of HBr is explored and improvements in the results of quantitative analyses are demonstrated.     

Deconvolution from panel data with unknown error distribution

We devise a new method of estimating a distribution in a deconvolution model with panel data and an unknown distribution of the additive errors. We prove strong consistency under a minimal condition concerning the zero sets of the involved characteristic functions.     

Rapid automatic identification and quantification of compounds in complex matrices using comprehensive two-dimensional gas chromatography coupled to high resolution time-of-flight mass spectrometry with a peak sentinel tool

Comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC × GC–MS) is a powerful tool for comprehensive analysis of organic pollutants. In this study, we developed a powerful analytical method using GC × GC for rapid and accurate identification and quantification of compounds in environmental samples with complex matrices. Specifically, we have developed an automatic peak sentinel tool, T-SEN, with free programming software, R. The tool, which consists of a simple algorithm for on peak finding and peak shape identification, allows rapid screening of target compounds, even for large data sets from GC × GC coupled to high resolution time of flight mass spectrometry (HRTOFMS). The software tool automatically assigns and quantifies compounds that are listed in user databases. T-SEN works on a typical 64 bit workstation, and the reference calculation speed is 10–20 min for approximately 170 compounds for peak finding (five ion count setting) and integration from 1–2 GB of sample data acquired by GC × GC–HRTOFMS. We analyzed and quantified 17 PCDD/F congeners and 24 PCB congeners in a crude lake sediment extract by both GC × GC coupled to quadrupole mass spectrometry (qMS) and GC × GC–HRTOFMS with T-SEN. While GC × GC–qMS with T-SEN resulted in false identification and inaccurate quantification, GC × GC–HRTOFMS with T-SEN provided correct identification and accurate quantification of compounds without sample pre-treatment. The differences between the values measured by GC × GC–HRTOFMS with T-SEN and the certified values for the certified reference material ranged from 7.3 to 36.9% for compounds with concentrations above the limit of quantification. False positives/negatives were not observed, except for when co-elution occurred. The technique of GC × GC–HRTOFMS in combination with T-SEN provides rapid and accurate screening and represents a powerful new approach for comprehensive analysis.     

Rapid estimation of TOC in a marine urban sewage area by UV spectral deconvolution

A simple and rapid procedure for on-site qualitative and quantitative analysis of organic matter from discharges of municipal wastewater in seawater has been developed. This method is based on the knowledge of the UV signal of both seawater and anthropogenic absorbing matter and on the mathematical deconvolution of the sample spectrum using reference spectra. The main application is the estimation of TOC at the direct outlet of the discharge. This quantitative application is obviously limited by the nature of organic compounds, but the UV estimation allowed us to have an overview of the composition and evolution of organic matter into the polluted area. The application of this procedure has been carried out to study the wastewater dilution into an area receiving urban discharges. Experiments showed satisfactory analytical features with a range of TOC values from 75 to 1500?µM C, and the comparison of the results with those obtained by reference method presented a reasonable correlation (r ²?=?0.9636) in the marine discharge. The results have also allowed us to quickly estimate the plume evolution at the sea surface and in depth. This alternative method could be integrated in a portable device for on-site analysis and multiplication of measurements for relevant results, or in a continuous flow analyser.     

Recent results on the use of model resolution functions for the deconvolution of depth profiling data

The paper by Markarov [Surface and Interface Analysis, 20 , 1993, pp. 821–826] considered the important problem of deconvolution of depth profiling data. In this note, we consider the problem of convoluting the initial Gaussian profile with a double exponential resolution function. The paper by Markarov only provided an asymptotic treatment of this problem. Here, we provide exact results, various approximations as well as a simple computer program. Copyright © 2007 John Wiley & Sons, Ltd.     

Contribution of different granulometric populations to powder reactivity

In this article, different population contributions of quartz powders to chemical reactivity in pozzolanic reaction were studied. Deconvolution software was used to show the different particle populations of each product. Reaction of quartz powder with lime in the pozzolanic reaction at 20 °C shows that reactivity of each powder population depends on its particle size. Adsorbed fine particles on coarse particle surfaces have a significant role in the first term of the reaction. In a second term, the micropo...     

Hydration properties of symmetric chain and asymmetric chain sphingomyelin bilayers

Hydration properties of lipid bilayer systems are compared for symmetric chain sphingomyelin (N-palmitoylsphingomyelin) and asymmetric chain sphingomyelin (N-lignoceroylsphingomyelin). These sphingomyelins were semisynthesized by a deacylation- reacylation process with a natural sphingomyelin used as a starting material. The number of differently bound water molecules was estimated by a deconvolution analysis of the ice-melting curves obtained by a differential scanning calorimetry (DSC) and was used to construct a water distribution diagram for these water molecules. Similarly to a natural sphingomyelin used for comparison, the asymmetric chain sphingomyelin was found to form small size vesicles having an internal cavity and incorporate 15 water molecules per molecule of lipid into its cavity, in contrast with 5 H₂O/lipid for freezable interlamellar water observed for large size multilamellar vesicles formed by the symmetric chain sphingomyelin.     

Combination of stir bar sorptive extraction–retention time locked gas chromatography–mass spectrometry and automated mass spectral deconvolution for pesticide identification in fruits and vegetables

Fruit and vegetable samples collected at a local market were analyzed using stir bar sorptive extraction (SBSE) followed by thermal desorption, retention time locked (RTL) gas chromatographic separation and full scan mass spectrometric determination. Although the technique is proven to have sufficient extraction efficiency and productivity in pesticide analysis, the full scan chromatograms are loaded with matrix components making qualitative evaluation time consuming and too difficult to be adequate for routine laboratory screening. Identification can be facilitated to a great extent with evaluation methods provided by data evaluation software. Through the comparison of three evaluation methods we found that the mass spectral deconvolution software AMDIS supports most the decision making process, performing best in discovering positive hits and reducing data for supervision, making SBSE suitable for routine applications.     

Restoration of Degraded Images with Maximum Entropy

We present a Maximum Entropy based approach to the restoration ofdegraded images as an alternative to restorationtechniques using inverse Wiener filtering.The method we discuss applies in particularto images corrupted by a relativelyhigh system noise. A variety of experimental results supportingour imaging model are included.