Thermal behavior and decomposition kinetics of ETN and its mixtures with PETN and RDX

Erythritol tetranitrate (butane-1,2,3,4-tetrayl tetranitrate, ETN) has become one of the most synthesized improvised explosives nowadays as it can be found on public internet discussion boards. However, the low melting point, nitrocellulose gelling ability, high energy content, and availability of its precursor make the substance potentially useful in industry as an energetic component or additive in certain gun propellants. Mixtures of ETN with other high explosives are also frequently discussed on web pages dealing with improvised explosives. This article describes thermal behavior and decomposition kinetics of pure ETN and its mixtures with pentaerythritol tetranitrate and cyclonite (1,3,5-trinitro-1,3,5-triazinane, RDX). The thermal behavior and decomposition kinetics of such mixtures are described using non-isothermal DSC and TG techniques. Kissinger method, Soviet manometric method, and modified Kissinger–Akahira–Sunose method were used for data evaluation.     

The nanostructural analysis of hydrogenated silicon films based on positron annihilation studies

Due to the complex nature of hydrogenated amorphous and microcrystalline silicon (a-Si:H; μc-Si:H) a profound understanding of the Si:H nanostructure and its relation to the Staebler–Wronski effect (SWE) is still lacking. In order to gain more insight into the nanostructure we present a detailed study on a set of Si:H samples with a wide variety of nanostructural properties, including dense up to porous films and amorphous up to highly crystalline films, using Doppler broadening positron annihilation spectroscopy (DB-PAS) and Fourier Transform infrared (FTIR) spectroscopy. The results obtained from these material characterisation techniques show that they are powerful complementary methods in the analysis of the Si:H nanostructure. Both techniques indicate that the dominant type of open volume deficiency in device grade a-Si:H seems to be the divacancy, which is in line with earlier positron annihilation lifetime spectroscopy (PALS), Doppler broadening (DB) PAS and FTIR studies.