Pyrolysis of Energetic Ionic Salts Based on Nitrogen-rich Heterocycles

Energetic ionic salts based on nitrogen-rich heterocycles are expected to usher in a new era in the fields of propellants, explosives, and pyrotechnics owing to their excellent combustion characteristics, green nature, and the ability to tailor them based on requirements. The review focuses on an important aspect of these compounds, other than the synthesis procedure and physico-chemical characterisation, that is frequently overlooked, i.e. the decomposition pathways and the associated chemical kinetic parameters, which are essential to elucidate and simulate their combustion characteristics. The reaction mechanisms of four major families of energetic ionic salts, explored by various experimental and numerical techniques, are reported in detail

Green Hypergolic Ionic Liquids: Future Rocket Propellants

Hydrazine and its derivatives have been used as standard propellants for spacecraft propulsion systems since the 1960s, despite being highly toxic and carcinogenic. The propellant synthesis community has constantly been looking for green alternatives for the same. Hypergolic ionic liquids (HILs) with several attractive properties, such as high energy content, high bulk density, low vapor pressure, and low toxicity, have been proposed as an alternative to hydrazine and its derivatives. In the present study, the theoretical performance of sixty-eight HILs was studied at a combustion chamber pressure of 3 MPa and a nozzle expansion ratio of 40. The specific impulse and density specific impulse of the HILs were calculated with white fuming nitric acid (WFNA), inhibited red fuming nitric acid (IRFNA), and nitrogen tetroxide (NTO) as oxidizers. The specific impulse of 2,2-dimethyltriazanium nitrate (HIL-1) was found to be 23 s higher than monomethylhydrazine (MMH), whereas its density-specific impulse was found to be 123 g-s/cm3 higher than MMH. The gains in the specific impulse and density specific impulse coupled with other desirable “green” properties for several HILs are expected to establish them as potential replacements for hydrazine and its derivatives

Effect of Agroforestry System on Soil Properties in an Acid Inceptisol under Tropical Climatic Situation of Eastern India

An experiment was carried out using the existing Field of AICRP on Agroforestry Project in Central Research Station of O.U.A.T, Bhubaneswar at a Latitude 20015’ N and longitude of 850 52’ E in order to study the effect of agroforestry system on soil properties in the surface soil. In the year 2013, the system had two tree species Dalbergia sissoo and Gmelina arborea along with 4 intercrops such as pineapple, mango ginger, turmeric and arrowroot. Soil samples were collected after 13 years of agroforestry system in the post harvest period during 2014-15 for soil properties study. With Agro forestry system there was improvement in soil bulk density, organic matter and available nutrients as compared to open field where there was loss of nutrients. Between the trees, Gmelina arborea maintained higher level of soil organic carbon, available N, available P and available K on top soil than Dalbergia sissoo. Inclusion of intercrops maintained significantly higher organic carbon and available status of NPK on the surface soil than non inter cropped system. Pine apple crop recycled a major part of the absorbed N and K causing more accumulation of N and K in all the treated plots. Among the eight combinations of tree and intercrop, Gmelina arborea +pine apple combination is considered the best agroforestry system for maintaining better soil health and sustaining the system in acidic Inceptisols under humid tropical climatic situation

A numerical and experimental study of the decomposition pathways of guanidinium nitrate

The thermal decomposition behaviour of guanidinium nitrate (GN), an energetic material, was analysed using a combined experimental and computational approach. Simultaneous thermogravimetric analysis, Fourier transform infrared spectroscopy and mass spectrometry (TG-FTIR-MS) experiments were carried out at three different heating rates under closed and open crucible conditions. A two-stage decomposition process was observed, and the major gases evolved were found to be NH3, N2O, NO2 and CO2. Quantum mechanics based ab initio computations were performed to evaluate the possible decomposition pathways available for GN. Results indicate that decomposition of GN is not initiated in the condensed phase as the guanidinium cation and the nitrate anion are highly stable. The most likely mechanism involves isomerization of GN followed by a proton transfer in the gas phase to yield nitric acid and guanidine. These products then further react to form nitroguanidine (NQ) and H2O. NQ dissociates via several competing pathways to yield NH3, N2O, H2O and CO2. HNO3 decomposition can help explain NO2 formation. The residue left towards the end of TG can be attributed to dimerization and trimerization reactions of cyanamide

Tachycardia and fever after packed red cell (PRC) infusion: A case report

A 56-year-old female patient with a body weight of 60 kg was brought to the hospital with hematemesis and received one unit of packed red cells (PRCs) for this condition. After 30 min, the patient experienced tachycardia of 120 beats/min and an increased body temperature of 102°F. The patient had no relevant medical history of allergy or similar episodes in the past. The patient was not suffering from any coagulopathies or sickle cell anaemia, which is a prevalent condition in the region. The patient was receiving the PRC for the first time. After this event, the infusion was stopped and immediately injection meropenem, pantoprazole and ondansetron IV were administered. The patient's condition normalised after 6 h. No re-challenge was given after the recovery of the patient. Suspected ADR was analysed according to the World Health organization (WHO) causality assessment scale and the causality was “Possible”. Meticulous monitoring and prompt therapy were provided. The patient was discharged after observing for 24 h. The adverse drug reaction was possibly caused due to the PRCs

Theoretical studies on the propulsive and explosive performance of strained polycyclic cage compounds

Compounds consisting of a carbon-based cage have a highly strained molecular structure and have become the subject of interest in recent years because they possess high heat of formation and so are highly energetic. In the present work, ab initio molecular modelling calculations have been used for analysing 28 carbon-cage structures with the aim of identifying the best candidates for synthesis particularly for use in propellant compositions. Density functional theory (B3LYP) was employed for the geometry optimisation of the proposed molecules using the 6-311++G(d,p) basis set. Calculated heats of formation and densities of the compounds have been used from the optimized structures to compute their specific impulses and density specific impulses in various configurations (solid and liquid) with an eye on propulsion applications. Detonation properties of the compounds have also been reported and comments have been made correlating the properties of the cage compounds with their molecular structures

Mucinous carcinoma of the male breast with axillary lymph node metastasis: Report of a case based on fine needle aspiration cytology

Pure mucinous carcinoma of the male breast is an uncommon malignant breast neoplasm and extremely rare is its metastasis in axillary lymph nodes. Most of these cases have been diagnosed after surgical resection with only a few cases diagnosed on fine needle aspiration cytology (FNAC). Although FNAC is well established in the evaluation of breast masses in females there are few reports in males. We are presenting a case of pure mucinous carcinoma of the male breast with metastasis in axillary lymph nodes in a 75-year-old male diagnosed by FNAC and confirmed on histopathology

Synthesis and energetic properties of high-nitrogen substituted bishomocubanes

Synthesis, thermodynamic characterization, and energetic properties of three novel high-nitrogen bishomocubane-based compounds DADMBHC, DTetzBHC and DPTrizDMBHC are reported here. These compounds have higher heats of formation (HoFs) and higher energy densities as compared to traditional hydrocarbon fuels. Densities, gas phase HoF and their optimized molecular structure geometries were calculated with various levels of theory. In general, the calculated HoFs of these compounds turn out to be extremely high. Ballistic properties such as vacuum specific impulse and density vacuum specific impulse were calculated using the NASA Chemical Equilibrium and Applications utility. Propulsive properties were compared with liquid bipropellants (RP1) and solid propellants (AP) and explosive properties were compared with RDX. The density specific impulse demonstrated an improvement of 35 s for DADMBHC and DTetzBHC over standard liquid hydrocarbon HTPB, thus showing promise as possible monomers to replace HTPB as a fuel-binder. The density specific impulses of these compounds were also found to be significantly higher than that of RP1, e.g. that of DADMBHC was found to be higher by 84 s, making them potentially good candidates as propellants for use under volume-limited conditions. The detonation properties showed that these compounds have low potential as explosives. TGA, coupled with IR spectroscopy, revealed that DADMBHC and DPTrizDMBHC evaporate readily while DTetzBHC decomposes partially