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We undertake a spectral study of a sample of bright X-ray sources taken from six XMM-Newton fields at high galactic latitudes, where AGN are the most populous class. These six fields were chosen such that the observation had an exposure time more than 60 ksec, had data from the EPIC-pn detector in the full-Frame mode and lying at high galactic latitude | b|>25. The analysis started by fitting the spectra of all sources with an absorbed power-law model, and then we fitted all the spectra with an absorbed power-law with a low energy black-body component model.The sources for which we added a black body gave an F-test probability of 0.01 or less (i.e. at 99% confidence level), were recognized as sources that display soft excess. We perform a comparative analysis of soft excess spectral parameters with respect to the underlying power-law one for sources that satisfy this criterion. Those sources, that do not show evidence for a soft excess, based on the F-test probability at a 99% confidence level, were also fitted with the absorbed power-law with a low energy black-body component model with the black-body temperature fixed at 0.1 and 0.2 keV. We establish upper limits on the soft excess flux for those sources at these two temperatures. Finally we have made use of Aladdin interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED) to identify the X-ray sources in our sample. For those sources which are identified in the NED catalogue, we make a comparative study of the soft excess phenomenon for different types of systems. [ABSTRACT FROM AUTHOR]

The article illustrates the application of bulk-sample and spatially resolved synchrotron X-ray absorption spectroscopy (XAS) for characterizing chemical species of contaminants in soils and for determining the uniqueness of trace element reactivity in different soil microsites in the U.S. It discusses the opportunities provided by spatially resolved X-ray techniques for following chemical changes within soil microsites that serve as highly localized chemical microreactors of unique composition. It highlights the use of information and principles developed from microscale soil chemistry for predicting macroscale and field-scale behavior of soil contaminants as one challenge in research.

The article examines the most significant and essential progress in X-ray spectrometry within the period of 2004 to 2005 in the U.S. The review covers developments and improvements in the performance of detection and instrumentation of X-ray techniques and X-ray optics. The goals of research and development activity in the field of detectors are to arrange less material in the detector bulk, to build high-speed readout electronics and to construct large radiation-tolerant detectors. However, this article is limited only on selected minority of the published papers and current trends in analytic chemistry.