Electrical performance of ZrC ceramics

In the present study it was possible to provide evidence that ZrC ceramics – regarding their electrical-mechanical and thermal properties – are an attractive substitute for tungsten and molybdenum in the field of refractory materials and heating elements. For this purpose, the heating behavior of ZrC materials was investigated in a specific test stand under high vacuum conditions (10⁻⁶ mbar) at temperatures above 2000 °C. In addition, the applicability of ZrC as an electrical heating element was investigated in terms of geometric design and long-term behavior. Examinations after the heating tests did not reveal any significant changes in the material.     

Study on the influence of ageing on thermal decomposition of double‐base propellants and prediction of their in‐use time

A comparative study of the thermal decomposition of naturally and artificially aged double‐base propellants has been carried out at five different heating rates in a dynamic nitrogen atmosphere using differential scanning calorimetry (DSC) technique. The results show that there is only one decomposition peak on DSC curves, and this decomposition has been accelerated by ageing. The influence of the heating rate on the DSC behaviour of the propellants was verified. The kinetic parameters such as activation energy and frequency factor and the thermodynamic parameters such as the enthalpy of activation, free energy of activation and critical explosion temperature for the compounds were obtained from DSC data using non‐isothermal methods proposed by Kissinger and Ozawa. On the other hand, a prediction of the in‐service period by van't Hoff's equation was performed and compared with the experimental results in order to check the constancy and validity of this method. As a result, the prediction procedure used to obtain the time–temperature profile was achieved with good accordance. Copyright © 2012 John Wiley & Sons, Ltd.     

Stabilizers for nitrate ester-based energetic materials and their mechanism of action: a state-of-the-art review

Aliphatic nitrate esters are currently the most widely used energetic ingredients in single-, double-, and triple-base propellants. These nitrate esters are unstable at ambient conditions, and stabilizing agents should be incorporated into the energetic compositions to inhibit and slow down the decomposition reactions that can occur. However, the currently used stabilizers present a number of environmental and human health issues. To overcome these shortcomings, many stabilizers have been appeared in the past few decades and continue to be developed. Furthermore, several analytical techniques have been introduced to monitor the stability of nitrate ester-based energetic materials as well, since the existing ones could not be efficiently applied. Therefore, this review paper discusses and summarizes the current and emergent stabilizers as well as their mechanisms of action. A critical and analytical examination of their advantages and drawbacks is made.     

Thermisch gespritzte Schichten im System Al2O3–Cr2O3–TiO2 – ein Update

With exception of ZrO₂, the individual oxides and binary compositions in the system Al₂O₃–Cr₂O₃–TiO₂ are the most important oxide materials for the preparation of thermally sprayed coatings. In this contribution selected results of recent own research activities are summarized. This includes the comparison of microstructures, phase compositions, and properties of coatings, deposited by atmospheric plasma spraying (APS) and high velocity oxy‐fuel (HVOF) spraying. The possibilities arriving from the use of suspensions as feedstock are reviewed. Special attention is paid to the advantage of use of binary compositions in this system. Tribological, electrical and corrosion properties of the coatings are discussed.     

5-Nitro-1,2,4-triazole-3-one: A review of recent advances（英）

The 3-Nitro-1,2,4-triazole-5-one (NTO) is a high energydensity materials of keen interest for both commercial and scientific worlds owing to its reduced sensitivity, better thermal stability and high performances. It plays a significant role to replace the current energetic ingredients. In this review, we summarize various strategies involved in the synthesis of NTO as well as the existing approaches to tailor its particle morphology and sizes. The most prominent properties of NTO, such as insensitivity and performance, which are usually required to produce efficient formulations,have been concisely discussed. In addition, this overview reports on some newer forms of NTO including derivatives and co-crystals available inthe literature, which can enhance the NTO features and extend its applications. The advantages and shortcomings of various NTO forms for specific and potential use are also highlighted together with the attempts made to overcome these issues. Therefore, efforts will certainly continue to improve characteristics and performances of NTO either by chemical modification or by co-crystallization in order to produce promisingformulations for widespread applications in the near future.     

Study of (Solid–Liquid) Phase Equilibria for Mixtures of Energetic Material Stabilizers and Prediction for Their Subsequent Performance

Solid-liquid equilibria for three binary mixtures of 2-nitrodiphenylamine (1) + diphenylamine (2), ethyl centralite (1) + N-ethyl-4-nitro-N-nitrosoaniline (2), and 2,2 $^{\prime }$ -dinitrodiphenylamine (1) + N-ethyl-4-nitro-N-nitrosoaniline (2) were measured using a differential scanning calorimeter. Simple eutectic behaviors for these systems were observed. The experimental results were correlated by means of original and modified NRTL, Wilson, and UNIQUAC equations. The root–mean–square deviations of the solubility temperatures for all measured data vary from 0.63 K to 3.73 K and depend on the particular model used. The best solubility correlation was obtained with the UNIQUAC model.     

Quantum Fluctuations in Equilibrium Superradiance

Abstract

The role of the quantum fluctuations of the order parameter in a second-order phase transition is discussed, for a superradiant model. The mean field equations and the equation of the critical temperature are obtained. The change of the value of the critical exponent of the specific heat α is connected with the supplementary dimension introduced by the frequency dependence of the field variables. The functional integral method is used, most of the calculations being performed within the Gaussian approximation.     

Modern residential energy inequalities in Indonesia: spatial and income analyses

ABSTRACT

This study put forward the inequality issues in modern residential energy consumption from both income and spatial viewpoints, with special regard to the Indonesian case. Energy inequality was viewed from the perspective of energy justice in both distribution and recognition. This study employed qualitative analysis with Theil’s, Gini, and mixed-Gini index methods. The energy usage inequalities have declined, both overall and by the dimensions of spatial and income levels, except in urban areas. However, this paper found that some groups were susceptible to fall into energy-poor, especially residents in rural areas, remote areas, and eastern Indonesia. Besides improving a more stable electricity grid, the government should continue the energy-saving solar lighting (LTSHE) program and promote small-scale decentralized technologies. LPG distribution should be improved. A program such as the cheap clean stove needs to be developed to reach those without access to clean cooking fuel.