Stand-alone Ayurvedic intervention with home quarantine in COVID-19 - Outcomes of clinical practice.

This article reports the treatment outcomes of 167 COVID-19 positive patients who were treated with a stand-alone Ayurvedic therapeutic intervention. The main outcomes are quick resolution of symptoms, no deterioration in any of the cases and safe treatment for patients with multiple comorbidities. There was no observed mortality. There were no adverse events due to the Ayurvedic medications. The treatment was undertaken in an out-patient setting and at a low cost. The efficacy and safety of the treatment, and the quick resolution of symptoms were demonstrated. This shows that if COVID-19 patients are treated with Ayurvedic medicines early in the course of COVID-SARS-2 infection, Ayurveda has the potential to prevent progression and deterioration of the disease, with decreased morbidity and mortality.

Modeling and validation of polyurethane based passive underwater acoustic absorber.

The acoustic behavior of an acoustically transparent polyurethane and an interpenetrating polymer network of polyurethane with polydimethyl siloxane were studied using dynamic mechanical analysis, finite element modeling, and experimental evaluation of acoustic properties in a water-filled pulse tube setup. Dynamic mechanical measurements in the temperature range -50 °C to +70 °C were carried out, and the data were used for time temperature superposition to generate material behavior at high frequencies. These inputs were used for modeling the acoustic behavior of these materials using ATILA, which is a commercial finite element code, capable of computing transmission and reflection characteristics of materials. From this data, absorption characteristics were computed. The results were compared with the experimental results obtained using a water-filled pulse tube facility.

Environmentally compatible next generation green energetic materials (GEMs).

This paper briefly reviews the literature work reported on the environmentally compatible green energetic materials (GEMs) for defence and space applications. Currently, great emphasis is laid in the field of high-energy materials (HEMs) to increase the environmental stewardship along with the deliverance of improved performance. This emphasis is especially strong in the areas of energetic materials, weapon development, processing, and disposal operations. Therefore, efforts are on to develop energetic materials systems under the broad concept of green energetic materials (GEMs) in different schools all over the globe. The GEMs program initiated globally by different schools addresses these challenges and establishes the framework for advances in energetic materials processing and production that promote compliance with environmental regulations. This review also briefs the principles of green chemistry pertaining to HEMs, followed by the work carried out globally on environmentally compatible green energetic materials and allied ingredients.

Quantum chemical, ballistic and explosivity calculations on 2,4,6,8-tetranitro-1,3,5,7-tetraaza cyclooctatetraene: a new high energy molecule.

Ab initio molecular orbital calculations have been carried out on 2,4,6,8-tetranitro-1,3,5,7-tetraazacyclooctatetraene, the tetramer of the series (NO(2)CN)(n) where n=1-4, using the Hartree-Fock theory with the 6-31 G(d) basis set. These calculations yield three conformers for the tetramer with D(4h), C(4h) and C(2) symmetries. The nonplanar conformer with the C(2) symmetry turns out to be 99.0 and 164.4kJmol(-1), respectively, lower in energy than the C(4h) and D(4h) conformers. The electron density topography - the density at the bond critical point - has been used as a measure of the CNO(2) strengths. Based on these bond strengths, heats of formation [obtained from the parametric model 3 (PM3) method] and specific decomposition energies, it may be concluded that (NO(2)CN)(4) is a promising candidate in the class of high energy molecules. Theoretically computed explosive (velocity of detonation, detonation pressure, etc.) and ballistic (characteristic velocity, specific impulse, etc.) parameters support these conclusions.

Studies on diaminoglyoxime (DAG): thermolysis and evaluation as ballistic modifier in double base propellant.

This paper reports thermolysis of diaminoglyoxime (DAG) and its evaluation as a ballistic modifier in double base propellant formulations. Differential scanning calorimetry (DSC) and simultaneous thermal analysis (DTA-thermogravimetric (TG)) revealed that DAG decomposes in two stages. Kinetics of initial stage of thermal decomposition of DAG evaluated from TG data gave activation energy (E(a)) of 153 kJmol(-1). The high-temperature Fourier transform Infrared (FTIR) spectra of DAG suggested preferential cleavage of NO and CNH2 during decomposition. Mass spectral data also suggest possibility of similar process. The hyphenated TG-FTIR data also revealed the evolution of gases containing species, such as CN, NH, OH and oxides of nitrogen during thermal decomposition. Evaluation of DAG as a ballistic modifier in RDX incorporated double base propellant formulations indicated that it brings down the pressure index to 0.17 compared to 0.79 for a control composition in the pressure range 6.9-8.8 MPa when used in combination with basic lead salycilate (BLS). The study suggests that combination of DAG and BLS need to be optimized to achieve more remarkable effects than BLS alone. It was observed that DAG does not have adverse effect on vulnerability and chemical stability of the propellant formulation.

Studies on salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA): potential energetic ballistic modifiers.

The Co/Cu/Ni/Fe salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA) were prepared and characterized during this work. All the salts exhibited exothermic decomposition in DSC. The FT-IR spectra of the gaseous products evolved during TGA of NTO salts indicated the release of NO2 and cleavage of NTO ring during the course of decomposition. Thermal decomposition of TABA salts also produced NO2 on decomposition. The transition metal salts enhanced the burning rates of AP-HTPB composite propellant evaluated during this work. The best catalytic effect was obtained with Fe-NTO salt which increased the burning rate to the extent of approximately 80% as well as brought down the pressure index (n) to 0.18 (2-9MPa).

Synthesis, characterization, thermolysis and performance evaluation studies on alkali metal salts of TABA and NTO.

The lithium (Li) and potassium (K) salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA) were prepared and characterized during this work. The synthesis was carried out by addition of a solution of lithium/potassium hydroxide to the aqueous solution of NTO and TABA, respectively. The products were characterized by elemental analysis, metal content determination and Fourier Transform Infrared (FTIR) Spectrum. Differential scanning calorimetry (DSC) profile indicated that Li and K salts of NTO and TABA undergo exothermic decomposition in the temperature range of 257-360 degrees C suggesting their energetic nature. The thermo gravimetric (TG) weight loss pattern revealed loss of water for Li/K salts of NTO and TABA in the temperature range of 115-155 degrees C. Sensitivity results revealed that the compounds are insensitive to impact and friction (impact sensitivity--height of 50% explosion>170 cm and friction insensitivity up to 36 kg) stimuli despite even the parent molecule of NTO salts (NTO) being HEM in the hazard category of 1.1. The FTIR spectra of the gaseous products evolved during TGA of NTO and TABA salts indicated the release of NO2. The formation of products such as LiNCO and KNCO was also observed in case of NTO salts, whereas that of CO2 and NH containing products was indicated in case of TABA salts during this study. In order to assess the performance as energetic ballistic modifiers (EBMs), NTO and TABA salts were incorporated in the ammonium perchlorate-hydroxyl terminated polybutadiene (AP-HTPB) composite propellants. The potassium salts enhanced the burning rate of the propellant. The best catalytic effect was obtained with K-TABA salt, which increased the burning rate to the extent of approximately 81% as well as brought down the n-value to 0.15 (pressure 2-9 MPa).

Spectro-thermal decomposition study of 1,4-dinitroglycoluril (DINGU).

Simultaneous thermal analysis and high temperature FTIR study of 1,4-dinitroglycoluril (DINGU) is reported. TG showed 90% weight loss in the temperature range 225-250 degrees C. Isothermal TG of DINGU showed about 70% weight loss in the temperature range 210-230 degrees C. Kinetic parameters evaluated using a computer program showed that alpha-t data are best described by the Avrami-Erofeev's equation for n=2 with an activation energy of 165 kJ/mol. The kinetics of decomposition of DINGU was followed by studying NH (3388 cm(-1)), CO (1770-1810 cm(-1)) and NO2 symmetric stretching (1565-1570 cm(-1)) IR bands. All three bands showed loss of intensity with temperature and time. alpha-t data of decomposition with respect to NO2 stretching was again best described by the Avrami-Erofeev's equation for n=2. Gaseous decomposition products observed in the IR were N2O, NO2, CO2, HCN and NO. PM3 and Hartree-Fock level calculations on various bond lengths, bond angles and dihedral angles were computed to support the analysis of decomposition study using TG and IR. The data showed that CN and NH bonds are much shorter than the NN bonds, indicative of the weaker NN bond and hence, the possibilities of rupture of the same bond preferentially. This paper also discusses the sensitivity and performance properties of DINGU.