Chirality plays a major role in biological processes, and the enantiomers of a bioactive molecule often possess different biological effects. For example, all pharmacological activity may reside in one enantiomer of a molecule, or enantiomers may have identical qualitative and quantitative pharmacological activity. In some cases, enantiomers may have qualitatively similar pharmacological activity, but different quantitative potencies.
This book is the second in the series of publications in this field by this publisher, and contains a number of latest research developments on ionic liquids (ILs). This promising new area has received a lot of attention during the last 20 years. Readers will find 30 chapters collected in 6 sections on recent applications of ILs in polymer sciences, material chemistry, catalysis, nanotechnology, biotechnology and electrochemical applications.
This chapter deals with blind deconvolution and blind separation of convolutive mixtures. Blind deconvolution is a signal processing problem that is closely related to basic independent component analysis (ICA) and blind source separation (BSS). In communications and related areas, blind deconvolution is often called blind equalization. In blind deconvolution, we have only one observed signal (output) and one source signal (input).
Independent Component Analysis (ICA) is a signal-processing method to extract independent sources given only observed data that are mixtures of the unknown sources. Recently, Blind Source Separation (BSS) by ICA has received considerable attention because of its potential signal-processing applications such as speech enhancement systems, image processing, telecommunications, medical signal processing and several data mining issues.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Algorithms for Blind Components Separation and Extraction from the Time-Frequency Distribution of Their Mixture
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Fixed-Point Algorithms for the Blind Separation of Arbitrary Complex-Valued Non-Gaussian Signal Mixtures
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article MAP-Based Underdetermined Blind Source Separation of Convolutive Mixtures by
The column is the only device in the high-performance liquid chromatography (HPLC) system which actually separates an injected mixture. Column packing materials are the “media” producing the separation, and properties of this media are of primary importance for successful separations.
Choice of Stationary Phase
Ideally for a reversed-phase separations, the retention factors (k) for all com-
ponents in a sample should lie between 1 and 10 to achieve separation in a
reasonable time. For a given stationary phase the k of a particular component
can be controlled by changing the solvent composition of the mobile phase.
However, the impact of eluent composition will depend on the type of sta-
tionary phase and the nature of the components in the mixture.
The most widely used analytical separation technique for the qualitative and quantitative determination of chemical mixtures in solution in the pharmaceutical industry is high-performance liquid chromatography (HPLC). However, conventional detectors used to monitor the separation, such as UV, refractive index, ﬂuorescence, and radioactive detectors, provide limited information on the molecular structure of the components of the mixture. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) are the primary analytical techniques that provide structural information on the analytes.
Petroleum mixtures consist primarily of relatively unreactive complex hydrocarbons covering a wide boiling range. Such mixtures are difficult to separate by most analytical techniques. Therefore, the petroleum industry has for many years played a leading role in the development of chromatographic methods of analysis. Since the last book specifically concerned with chromatographic analysis of petroleum appeared 15 years ago, numerous advances have been made including developments in liquid and supercritical fluid chromatography, ...
Recent advances in mass spectrometry have rendered it an attractive and versatile tool in industrial and academic research laboratories. As a part of this rapid growth, a considerable body of literature has been devoted to the application of mass spectrometry in clinical studies. In concert with separation techniques such as liquid chromatography, mass spectrometry allows the rapid characterization and quantitative determination of a large array of molecules in complex mixtures.
Chromatography was gained more importance initially after discovered in the
preparative chromatography using large amount of the sample for the separation all
components properly and collect each in their pure forms. Recently analytical
chromatography found many application areas. The purpose of preparative Analytical
chromatography is done normally with smaller amounts of material and is for
measuring the relative proportions of analytes in a mixture after discovered some
detectors which need very low amount of the analyte and have proper detection
The Wurtz reaction is limited to the synthesis of symmetric
alkanes from alkyl iodides & bromides.
If two dissimilar alkyl halides are taken as reactants, then
the product is a mixture of alkanes that is, often, difficult to
A side reaction also occurs to produce an alkene.
The side reaction becomes more significant when the alkyl
halides are bulky at the halogen-attached carbon.
Convolutive Mixtures and Blind Deconvolution
This chapter deals with blind deconvolution and blind separation of convolutive mixtures. Blind deconvolution is a signal processing problem that is closely related to basic independent component analysis (ICA) and blind source separation (BSS). In communications and related areas, blind deconvolution is often called blind equalization. In blind deconvolution, we have only one observed signal (output) and one source signal (input). The observed signal consists of an unknown source signal mixed with itself at different time delays.
Air samples for formaldehyde and acetaldehyde were collected on treated silica-gel
cartridges (P/N WAT047205, Waters Corp.) using separate pumps. Sampling flow rates were
2.0 L min-1
collected over 15 min to 30 min yielding sample volumes of about 30 L to 60 L.
Each cartridge was extracted with 2 mL of acetonitrile. Extracts were analyzed by high-
performance liquid chromatography with a diode array detector at a wavelength of 365 nm
following ASTM D 5197 (ASTM, 1997a). Extract concentrations were determined from multi-
point calibrations of external standard mixtures. ...
A compound is different than a simple mixture of elements. If hydrogen and oxygen
are mixed, the result is a colorless, odorless gas, just like either element is a gas
separately. A spark, however, will cause the molecules to join together; this will liberate
energy in the form of light and heat. Under the right conditions, there will be a violent
explosion, because the two elements join eagerly. Water is chemically illustrated