Recent advances in catalytic combustion of AP-based composite solid propellants

This review paper covers the forensic-relevant literature for the analysis and detection of explosives and explosives residues from 2016-2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/Resources/Documents#Publications.

Interpol review of detection and characterization of explosives and explosives residues 2016-2019

rGO–Fe2O3 composites were prepared using different solvents (distilled water, ethanol, N-methylpyrrolidone, ethyl acetate, n-butyl alcohol and N,N-dimethylformamide) via a simple solvothermal method and characterized by SEM, TEM, XRD, FT-IR, Raman and XPS techniques. Then, the catalytic action of rGO–Fe2O3 composites (prepared in different solvents), GO, rGO and pristine Fe2O3 on the thermal decomposition of ammonium perchlorate (AP) were studied using a TG-DSC instrument. DSC results showed that GO, rGO, pristine Fe2O3 and rGO–Fe2O3 composites could effectively promote the thermal decomposition of AP. Additionally, rGO–Fe2O3 fabricated in N,N-dimethylformamide (DMF) solvent possesses the best catalytic performance among the investigated materials. This result can be attributed to the better dispersibility of Fe2O3 nanoparticles on graphene oxide prepared in DMF solvent, which was confirmed by SEM and TEM imaging. The high temperature decomposition exothermic peak (HTP) and the apparent activation energy of AP are reduced by 119.6 °C and 173.3 kJ mol−1, respectively, in the presence of Fe2O3–rGO (DMF) composite.

Effect of rGO–Fe2O3 nanocomposites fabricated in different solvents on the thermal decomposition properties of ammonium perchlorate

Effect of metal additives on neutralization and characteristics of AP/HTPB solid propellants

The catalytic activity of nanoparticles of cobalt hydroxide supported on reduced graphene oxide, Co(OH)2|rGO, was studied for the decomposition of ammonium perchlorate (AP), the principal ingredient of composite solid propellants Co(OH)2|rGO was synthesized by an in situ reduction method, which avoided the application of extremely high temperatures and harsh processes rGO stabilized the nanoparticles effectively and prevented their agglomeration The performance of Co(OH)2|rGO as a catalyst was measured by differential scanning calorimetry Co(OH)2|rGO affected the high-temperature decomposition (HTD) of AP positively, decreasing the decomposition temperature of AP to 292 °C, and increasing the energy release to 290 J g−1 The diminution of the HTD of AP by Co(OH)2|rGO is in between the best values reported to date, suggesting its potential application as a catalyst for AP decomposition

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Nanohybrids of reduced graphene oxide and cobalt hydroxide (Co(OH)2|rGO) for the thermal decomposition of ammonium perchlorate

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

Catalytic effects of Cu-Co* on the thermal decomposition of AN and AN/KDN based green oxidizer and propellant samples

Potassium dinitramide (KDN) was incorporated in ammonium nitrate (AN) crystals in AN/KDN ratio of 90/10, 75/25 and 50/50 by a co-crystallization method. These mixtures were subjected to thermal decompositional studies (DSC-TG) using a Simultaneous Thermal Analyzer (STA). The catalysts used for the present studies were: i) cupric(II) oxide (CuO) and, ii) copper-cobalt based metal oxide (Cu-Co*). For all catalytic samples, 2% by weight percent of catalyst was added to the total weight of the samples. Thermal decomposition studies were carried out for all the oxidizer samples prepared. Thermal decompositional studies were carried out at three different heating rates, i.e. 3 K/min, 5 K/min and 10 K/min, and the kinetic parameters were computed using the model free FlynnWall-Ozawa equation. It has been observed that 50% KDN addition resulted in complete suppression of endothermicity indicating total supression of the phase changes of AN in this temperature range. Further, it was noticed that CuO acts as a better phase stabilizer for AN as compared to Cu-Co*. However, Cu-Co* considerably increased the net exothermic decompositional heat release (J/g) of AN.

/pdf/thermal-decomposition-and-kinetics-studies-of-an-kdn-and-4wucir4mzi.pdf

Thermal Decomposition and Kinetics Studies of AN, KDN and Their Mixtures with and without Catalysts

Rocket propulsion unit is very essential to for launching a space mission. Rocket propulsion has various types. In that hybrid rocket propulsion is an emerging and innovative technology with strong features such as economical, safe, and simple propulsion devices. On the other hand, few issues such as mixing ratio changes, low regression rates and inefficient mixing, restricts their application as a the major area. This research represents an improvement of an important issue, namely the low fuel regression rate. If an oxidizer velocity increases at the surface of fuel, the regression rate of fuel may increase due to the oxidizer flow above the burning surface produces shear stress, which erodes the fuel surface and causing the missing of fuel and air. Methods to increase the shear stress are to induce an oxidizer vortex inside the combustion chamber. In the current analysis, a diaphragm has been used to create the air vortex inside the solid fuel grain. A sequence of static rocket firing was accompanied for different position diaphragm. Operating condition has been kept constant for all the run. The results of six laboratory scale hybrid rocket test firing using polyvinyl chloride and gaseous oxygen are presented here. It has been found that the regression rate of solid fuel grain has been improved for the diaphragm cases.

Optimization of Regression Rate of Solid Fuel Grain in Hybrid Rocket Motor Physical Method

The present study attempts to analyze mental health problems in terms of anxiety, depression and probable post-traumatic stress disorder among women in Kosi flood affected areas of Bihar, India. STUDY DESIGN: CrossSectional Survey. METHOD: A crosssectional survey was conducted with total sample size of 250. 125 from high flood affected areas where populations were displaced for longer period of time from their original homeland and the same from the unaffected areas without displacement. Purposive sampling was used with those respondents who were willing to be part of the study. Ever-married women aged 17-49 were eligible for the study that were recruited after informed consent. Mental health was assessed by using the Hopkins Symptom Checklist-25 (HSCL-25) and Post Traumatic Stress Disorder Civilian Checklist. RESULTS: Between the two groups there was significant difference found in terms of anxiety (t=10.64, df=248, p=.000) and depression (t=10.32, df=248, p=.000). Further the affected group scored low in two domains of PTSD i.e. avoidance and arousal, whereas intrusion score was found to be average. Moreover, an inverse association of anxiety (r=-0.189 & p=.03), depression (r=-0.185 & p=.03) and PTSD (r=-0.245& p=.006) with age was found among the affected population. CONCLUSIONS: Anxiety and depression was found to be at an elevated level among affected groups, although respondents in the affected areas scored low in most of the domain of PTSD. Thus following a major disaster, there is a need to specifically address the mental health problems among women and provide adequate psycho-social support.

/pdf/mental-health-problems-in-the-wake-of-disaster-a-gendered-23k2j4vzq5.pdf

Puran Chandra Joshi

Papers

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

Catalytic effects of Cu-Co* on the thermal decomposition of AN and AN/KDN based green oxidizer and propellant samples

Thermal Decomposition and Kinetics Studies of AN, KDN and Their Mixtures with and without Catalysts

Optimization of Regression Rate of Solid Fuel Grain in Hybrid Rocket Motor Physical Method

Mental Health Problems in the Wake of Disaster: A Gendered Perspective