This review presents the work carried out by the international community in the area of sheet explosive formulations and its applications in various systems. The sheet explosive is also named as PBXs ...and is a composite material in which solid explosive particles like RDX, HMX or PETN are dispersed in a polymeric matrix, forms a flexible material that can be rolled/cut into sheet form which can be applied to any complex contour. The designed sheet explosive must possess characteristic properties such as flexible, cuttable, water proof, easily initiable, and safe handling. The sheet explosives are being used for protecting tanks (ERA), light combat vehicle and futuristic infantry carrier vehicle from different attacking war heads etc. Besides, sheet explosives find wide applications in demolition of bridges, ships, cutting and metal cladding. This review also covers the aspects such as risks and hazard analysis during the processing of sheet explosive formulations, effect of ageing on sheet explosives, detection and analysis of sheet explosive ingredients and the R&D efforts of Indian researchers in the development of sheet explosive formulations. To the best of our knowledge, there has been no review article published in the literature in the area of sheet explosives.
Recent advances in the field of chemometrics have provided us with an opportunity to determine if it is possible to extend numerical multivariate pattern recognition techniques beyond simple fuel ...characterization, to the identification of important compositional features that are related to fuel quality. This can include unique combinations of normally benign constituents that exert an impact on fuel stability. Fuels are ideal candidates for chemometric analysis, because we are often concerned with minute features within a complex compositional matrix. Two potential benefits of this approach are the development of diagnostic and predictive models that can relate fuel composition to quality. We have begun our investigation with studies of gas chromatography−mass spectrometry (GC−MS) data from fuels that have undergone various levels of thermally induced autoxidation. An analysis of variance (ANOVA) feature selection technique has been applied to locate features in the GC−MS data that change from sample to sample, thus allowing for a quick evaluation of how fuel composition is altered during stress. In this manner, evaporative losses, rather than fuel degradation, have been observed to dominate the chemical variations that are produced in naval distillate fuels (NATO F-76) during oven stress at 60 °C. Thermal stress in a closed low-pressure reactor (LPR) eliminates evaporative losses, and the chemical changes have been readily observed and modeled. A progressive change in composition during both oven and LPR stress is revealed from multi-way principal component analysis. Decomposition of windowed regions of the GC−MS data via parallel factor analysis provides a means of extracting the mass spectra of individual fuel constituents that change during stress. This illustrates the potential diagnostic capability of multi-way chemometric analysis of GC−MS data.
Our studies were focused on heavy metals (Cd, Cu, Zn, and Pb) and pesticides analysis from two different types of marine algae in order to assess their capabilities to be used as raw material for ...pharmaceutical purposes without risks for human health. The analysed algae, Cystoseira barbata and Ceramium rubrum, have been collected from Romanian Black Sea Coast in the southern zone Tuzla — Vama Veche where the biomass has increased in 2007. The used analytical techniques were atomic absorption spectrometry (AAS) for heavy metals and gas chromatography with electron capture detector (GC-ECD) and thermoionic specific detector (GC-TSD) for organochlorine respectively organo-phosphoric pesticides. The results indicate that heavy metals and pesticides levels are very low, similar with other reported data. The bioaccumulation abilities for studied contaminants are higher for Ceramium rubrum than for Cystoseira barbata.
A new method for atmospheric pressure ionization for LC and GC / mass spectrometry is reported. The atmospheric pressure laser ionization (APLI) is introduced as a powerful addition to the existing ...AP ionization techniques, in particular atmospheric-pressure chemical ionization (APCI), electrospray ionization (ESI) and atmospheric-pressure photoionization (APPI). APLI uses the step-wise two-photon ionization in contrast to the one-step VUV ionization process in APPI. The two-photon ionization strongly enhances the selectivity of the ionization process and the high photon flux during an ionization event drastically increases the sensitivity for non-polar compounds over that of APPI. The differences in the ionization will be discussed. The application of APLI investigations of PAH' s, hetero PHA's and halogenated polymers is presented. Furthermore, the combination of APLI with ESI and with gas chromatography opens up an extensive field of applications. In particular the GC/APLI combination provides a very selective and sensitive tool for the measurement of non-polar compounds. The introduction of REMPI labels to polar substances is used to demonstrate one possible application for this class of compounds.
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