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The technological breakthrough and the availability of multispectral remote sensing data have given rise to an ambitious challenge for the classification of the multispectral images accurately to support administrative bodies in decision-making. In this paper, the multi-temporal medium resolution Sentinel-2 imagery of the densely populated urban area of Delhi-NCR is classified using SVM into five different land cover classes, namely water bodies, barren land, vegetative region, road network, and residential areas. Further, the effect of different kernel functions of SVM on land cover classification performance is contrasted and the radial basis function (RBF) leads to the best results. The experimental results are compared with the maximum likelihood classification (MLC) method on different evaluation metrics. The SVM with RBF kernel shows promising improvements in the overall accuracy by 10 percent relative to the polynomial kernel and by 3 percent compared to MLC. The analysis of multitemporal spectral imagery of the study area reflects the increase in a built-up area (road network, Buildings), water bodies, and decrement in the area of barren land and vegetation.

Summers will become increasingly hot as a result of climate change, with temperatures rising above the thermoneutral range of animals, exposing them to heat stress. Oxidative stress, which is caused by an increase in reactive oxygen species, is one of the most dangerous side effects of long-term heat stress. In order to alleviate oxidative stress, metabolites required for living and development may be depleted, which can have a negative impact on animals’ growth and production performances, especially in chronic situations. Plant-derived phyto-feed additives with greater antioxidant quantity may benefit animals by lowering the effects of heat stress-induced oxidative stress. Improved pharmacological response and lack of adverse impact when compared to allopathic medications, phyto additives of curative benefit are becoming more frequent in medical research. Tinospora cordifolia is a popular term recognized as "Guduchi" or "Giloy" for its use in the treatment of different illness in naturopathic texts from the past. The bioactive components recovered from the plant, as well as its significance in prevention of illness, have helped the herbs to play a more active role in the field. It has antioxidant potential and can be exploited as a dietary additive to provide antioxidants for health benefits. The plant's common name, chemical components found in various portions of the plant, and biological functions are all covered in this review. In addition, they have potential as heat stress relievers in animals.

Seed oil bearing plants are going to be extinct from the nature due to over utilization for extraction of oil and climatic changes. They are very useful and effective in reducing different types of pain and neurological problems. Keeping this in view, an attempt has been made to document the medicinal and pharmacological values of Celastrus paniculatus through field and literature survey. The results revealed that the population of C. paniculatus is declining fast in forest areas. It was also noticed that the seed oil is rarely seen and available in local markets. Seed oil is used to treat neurological disorders and hence used as a brain tonic. The study recommends to reintroduce and advance works in pharmacological activities along with value addition and most importantly to conserve the plant from getting extinct.

Background: Heat stress in animals can occur when ambient temperatures are high and wind speeds are low, resulting in diminished growth, poor health, or even death. The purpose of this study is to evaluate the effect of Tinospora cordifolia (TC) on anti-stress and blood biochemical parameters in heat stressed (HS) Gaddi goats. Methods: Sixteen adult male Gaddi goats were split into four groups, T0H0 (no supplement no HS, control), T1H0 (diet fed with TC stem powder @ 5% of DMI with no HS), T0H1 (no supplement with HS) and T1H1 (diet fed with TC stem powder @ 5% of DMI with HS). The study was planned in a 2×2 factorial degin, with supplemetation TC stem powder (0 per cent vs. 5 per cent) and heat stress (normal vs. heat exposure) were the key effects to be studied over the 30-d trial period. Result: There was a significant interaction (supplement×stress×period) for oxidative stress indices. At the end of the experiment, the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and cortisol levels were higher in the T0H1 group goats than in the T1H1 group (similar to normal levels). The blood’s hematological and biochemical characteristics were equivalent among groups. However, after a 30-d trail, Hb and PCV levels in the blood were low in the stressed group. It can be culminated that, there was no significant change in hematological and blood biochemical parameters across groups, however animals’ antioxidant status were improved.

In this work, an integrated framework comprising of pixel-based classification, road network filtering, and multi-scale Gabor filter is proposed to address the various prevailing issues in road centerline extraction from VHR images. The proposed framework is composed of three steps; generation of the initial road map, road network filtering and road centerline extraction. In the first step, pixel-based classification using support vector machine (SVM) is performed on VHR imagery to classify it into the road and non-road classes. In the road network filtering step, to retain the road features in classified imagery, an edge-preserving guided filter is applied and to improve the veracity of road extraction, undesirable components are eliminated by shape feature analysis. Finally, the complete and accurate road centerline are obtained by combining multi-scale Gabor filter and fast parallel thinning algorithm. The maximum response from a multi-scale Gabor filter is not only used for extraction but also used for reconstructing the broken road network, which is due to occlusions and artifacts. The proposed framework is implemented on publically available VHR images dataset. The simulation outcomes reflect the dominance of the proposed framework on different quantitative evaluation parameters as compared to up-to-date methods.

Low molecular weight polyether (PE) or polyester polyols can produce novel elastomeric urethane products when cured with diisocyanate which are then utilized for formation of castable energetic com...

Detecting the fall of a person in indoor environment is a challenging issue especially for elderly and sick living alone. Cameras can continuously observes the scene and require little interaction with the user and therefore, are well suited for fall detection. In this paper, we propose a deep learning based framework for fall detection and classification. Further, we also apply different machine learning methods namely, Support Vector Machine (SVM) and decision tree after extracting important features to detect and classify the fall of a person. We compare our deep learning based framework with SVM and decision tree as well as other state-of-the-art methods. We have considered two different publicly available datasets for performing experiments. The experimental evaluation of our deep learning based proposed framework gives promising results and is comparable with other state-of-the-art methods.

To evaluate the effect of probiotics and essential oils on gut activities and metabolic studies of broiler, this experiment was carried out on day-old broiler chicks of Ven-Cobb 400Y strain (n=240) for 42 days. These broiler chicks were randomly distributed into 4 equal treatment groups with T0 (Control), T1, T2 and T3 with 60 birds in each group having 4 replicates of 15 birds each group. The treatments were T0 (Control, Standard broiler chicken diet as per BIS, 2007), T1 (Standard broiler chicken diet as per BIS, 2007 with oregano essential oil @ 0.15 gm/kg diet), T2 (Standard broiler chicken diet as per BIS, 2007 with probiotic (encapsulated Saccharomyces cerevisiae) @ 200 gm/ tonnes) and T3 (Standard broiler chicken diet as per BIS, 2007 with oregano essential oil @ 0.15 gm/kg diet and probiotic (encapsulated Saccharomyces cerevisiae) @ 200 gm/ tonnes). In the gut salmonella and clostridia count, ileal pH, dry matter digestibility and nitrogen retention showed significant (P0.05) difference between the groups. So supplementation of probiotics and essential oils modulate the activity of gut, increase the dry matter digestibility and nitrogen retention of broiler chicken.

For developing a new explosive formulation, a compatibility of polymeric binder with energetic compound is of most important in the pre-formulation stage. In this article, differential scanning cal...

A polyester (PE)-based polyurethane (PU) is widely used as a polymeric binder with an energetic compound especially more energetic octhydro-1,3,5,7 tetranitro-1,3,5,7 tetrazocine (HMX) in many energetic composite formulation. Compatibility between PE-based PU containing various curatives and HMX was studied through vacuum stability test, thermogravimetry and differential scanning calorimetry methods. PUs were obtained from the reaction of the prepolymer PE with various diisocyanates as curatives especially 4,4′ methylenediphenyl diisocyanate (MDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI) and 2,2,4 trimethylhexamethylene diisocyanate (TMDI), and these PUs were designated by PE/MDI, PE/IPDI, PE/TDI and PE/TMDI, respectively. The compatibility was judged through standardization agreement (STANAG) 4147. The results showed that the binary mixture of HMX with various PU, namely PE/MDI, PE/IPDI, PE/TDI and PE/TMDI, possessed a good compatibility. Kinetics of the binary mixture of HMX and PU was studied at three heating rates by means of the Ozawa and Kissinger methods. The calculated activation energy values of the binary mixture of HMX with PE/MDI, PE/IPDI, PE/TDI and PE/TMDI from the Kissinger method were found to be 483.9, 504.7, 502.2 and 485.3 kJ mol−1, respectively. For comparison, the values of neat PE and HMX were also calculated and were 118.2 and 299.3 kJ mol−1, respectively. The kinetic parameters were strongly depended on the type of the curative groups in the PE-based PU. Similar results were obtained from the Ozawa and ASTM E698 methods. The activation energy values calculated from the ASTM E698 method for the HMX/PE/MDI, HMX/PE/IPDI, HMX/PE/TDI and HMX/PE/TMDI samples were 204–215, 219–235, 145–157 and 172–246 kJ mol−1 in the low conversion of 0.05–0.15, respectively. Subsequently, these were demonstrated by a remarkable deviation in the activation energy in a range of 247–474, 235–499, 166–578 and 245–528 kJ mol−1 at the conversion (0.15–0.95), respectively.

Road network delineation from remote sensing imagery is useful in many applications related to humans in present days as it provides meaningful information which is very helpful in the field of transportation and other support systems of human civilization. However, the road network extraction from remote sensing images is a challenging problem because of various properties of road network altered by different factors. In this paper, a supervised multistage framework based on least square support vector machine (LS-SVM), mathematical morphology and road shape features is proposed to extract road networks from remote sensing images. In the first stage, after denoising the image using the nonlinear filter, the image is segmented using LS-SVM into two classes’ road or non-road but some non-road components like building structures, shadows of trees and other roads like objects are also classified as the road network. In the second stage, the morphology and primary shape features are used to remove the non-road objects. Finally, road centerlines are extracted using a method based on Euclidean distance transformation. The experimental results reflect the accuracy of the proposed work as compared to other road extraction methods.

Commercial fluororubber SKF 32, fluoroplastic F-32L, fluoroelastomer Kel-F, fluoroplastic FK 800 (labeled as SKF 32, F-32L, Kel-F and FK 800) and an in-house prepared poly(vinylidene fluori...

Cross-linked epoxy resin beads (ERBs) in macro size range were synthesized from biphenol diglycidyl ether (DGEBA) epoxy resin by suspension polymerization technique. The polymerization reaction of the epoxy resin with triethylenetetramine (TETA) was conducted in a presence of poly(vinyl alcohol) (PVA) as stabilizing agent at a temperature of 90 ± 2 °C with agitation rate of 800 rpm for 4 h. The amount of PVA was varied from 5 to 12.5 wt.% during the polymerization reaction which has shown a significant effect on the particle size and its distribution. The mean particle size and particle size distribution were evaluated by particle size analyzer. Results showed that the mean particle size increased with increasing the concentration of PVA. The mean particle size of ERB1, ERB2, ERB3 and ERB4 samples obtained at various concentration of PVA i.e. 5.0. 7.5, 10.0 and 12.5 wt.% was found to be 491, 475, 468 and 391 μm, respectively. Chemical structure, surface morphology and elemental composition were investigated through a Fourier Transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and SEM coupled energy dispersive X-ray spectroscopy, respectively. Thermal stability and kinetic parameters of the ERBs were also examined by a thermogravimetric analysis (TGA) technique. The thermal stability was found in the order of ERB1 ≥ ERB2 > ERB3 ≥ ERB4. The apparent activation energy and pre-exponential factor (A) of pure epoxy resin, ERB1 and ERB4 samples were calculated by applying the Kissinger method through thermogram peak temperature using first derivative thermogravimetric (DTG) data. The values of the activation energies of the pure epoxy resin, ERB1 and ERB4 samples were 235.3, 257.7 and 239.4 kJ/mol along with pre-exponential factor A of 1.0 × 1019, 1.5 × 1019 and 6.8 × 1018 s−1, respectively.

A compatibility of energetic compound with polymeric matrices is of prime importance in the pre-formulation stage for developing of new energetic composite formulations. In the present work, the co...

Thermal decomposition behavior and kinetics of aluminized polymer-bonded explosives (PBXs) based on l,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) bonded by hydroxyl-terminated polybutadiene (HTPB) and aluminum powder were investigated. Different from the literature, aluminized PBXs have undergone three-steps decomposition measured by thermogravimetry which could be best distinguished by derivative thermogravimetric study. Results revealed that the thermal decomposition behavior has been significantly influenced in the presence of Al and HTPB matrix, especially reducing the thermal stability than that of neat HMX. The reactivity of aluminized PBXs has been rationalized on the basis of dependence of the effective activation energy upon conversion determined via the popular isoconversional methods and compared with peak temperature at maximum reaction rate method. Resulting activation energy dependence obtained for the first stage has been found to be 82.2–231.3 kJ mol−1 in the region of 0.05–0.25 for the slow pyrolysis, followed by a significant variation in the anomalous activation energy with conversion from 446.9 to 1282.8 kJ mol−1 in the region of 0.3–0.6 for the second-stage decomposition of aluminized PBXs. The above-mentioned values are in good agreement with those obtained from the Kissinger method. Thermodynamic parameters for the formation of the activated complex, and critical temperature and self-accelerating for thermal explosion were also determined.

Cyclotrimethylenetrinitramine (RDX), an energetic propellant is associated with high sensitivity towards external stimuli and low thermal stability. To address these issues, the present study deals with the design of Estane 5702 thermoplastic urethane (TPU) based formulation as a novel nanoencapsulation system for the efficient storage of RDX. The RDX encapsulated polymeric formulations were prepared using the nanoprecipitation method. The results indicated the maximum encapsulation efficiency of around 87.7% for the TPU:RDX (1.6:8.4 w/w) encapsulated system. The structure and chemical composition were characterized using Field emission scanning electron microscopy (FESEM), particle size distribution (PSD), Fourier transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDX). The thermochemical properties and decomposition characteristics were determined using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The TGA analysis of RDX encapsulated polymeric systems displayed a relatively more controlled mass % loss as compared to bulk RDX. DSC analysis of RDX encapsulated spheres confirmed the crystalline phase of encapsulated RDX based on the endothermic peak around 203 °C and an exothermic peak at 240 °C, related to the melting and decomposition process of RDX respectively. The method of preparation of RDX encapsulated TPU formulations was facile, economical, and provided an effective route to achieve high encapsulation which can find promising applications in the storage of friction-sensitive RDX for both military and civil fields.

Falls and fall-related fractures of a person is a major health problem and this issue is increasing day-by-day, especially for elderly who live alone. In this paper, we propose a camera based, novel, real-time automated fall detection framework for indoor environments. We process the frames on-the-fly for real time processing. We first apply background subtraction for detecting moving personin the indoor environment. We then extract relevant geometric features to classify fall from other daily activities of a person. Support vector machine (SVM) is applied to distinguish fall and other activities of a person. We have done experiments on publicly available dataset which is UR Fall Dataset. Our experiments demonstrate that our proposed framework has achieved detection rates compared to the state-of-art methods.

Automatic road extraction from high resolution remote sensing (RS) satellite images of urban and semi-urban area is most challenging research area in recent years. In this work, a simple and elegant method of automatic road network extraction based on intensity thresholding and various morphological operations is proposed. The semi-urban remote sensing images contain various non-road elements (building structures, vegetative areas, parking and others) to identify the road in presence of such noise from RS images, the image is preprocessed to curtail the noise and road network is extracted by the proposed methods are the largest connected component and the road centerlines are detected by using thinning operation. The proposed technique is implemented on different RS images of semi urban area, experimental results are provided in this work and it can be seen that the road network is clearly traceable in finally processed image. The experimental results are evaluated by comparing ground road map data as reference and various quantitative measures like correctness, specificity, sensitivity, completeness and quality. Experimental results can be used in automated map analysis that has a very vast range of applications in the area of computer vision and navigation. The road network can also be extracted in many non-automated or semi-automated ways but these are prone to errors and need human intervene due to these reasons an automated system is required for the extraction of road from RS images.

Morphology-controlled precipitation of three powerful organic high energetic compounds (HECs) viz. cyclotrimethylenetrinitramine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2-methyl-1,3,5-trinitrobenzene (TNT) was achieved by two different processes, namely, drop-by-drop (DBD) and drop-to-drop (DTD) solvent-antisolvent interaction methods. Effect of different experimental parameters on the mean size and morphology of the prepared submicron-sized particles of HECs was investigated thoroughly. The DBD method favors the formation of nanosized particles of RDX and TNT at lower concentrations (5 mM). However, a significant increase in the mean particle size occurred at higher concentrations (25 and 50 mM). Formation of facetted crystals of RDX, HMX, and nanorods of TNT was observed at higher concentrations because of the interaction of crystal facets with the antisolvent. Relatively, smaller sized, spherical particles of RDX and HMX could be prepared through the DTD method even at higher concentrations (25 mM). The DTD method is a continuous process and hence is a facile method for industrial applications. X-ray diffraction and Fourier transform infrared spectroscopy studies revealed that RDX, HMX and TNT were precipitated in their most stable polymorphic forms α, β, and monoclinic, respectively. Differential scanning calorimetry showed that the thermal response of the nano-HECs was similar to the respective raw-HECs. A slight decrease in crystallinity and the melting point was observed because of the decrease in the mean particle size.

Nanoparticles of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were prepared by an antisolvent precipitation method. The effect of different experimental parameters such as temperature of antisolvent and concentration of solution on particle size of nano-HMX was studied systematically. A higher temperature (70°C) of the antisolvent and lower concentration of HMX in acetone (5 mM) favored the formation of smaller particles. Average particle size ranged from 30 to 128 nm under different experimental conditions. Nano-HMX was characterized using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectrophotometry, powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). FTIR, XRD, and TGA-DSC studies revealed that the nano-HMX was in the β-polymorphic form.

Considering the fundamental and most desirable characteristics of energetic materials, a series of 1,2,3-triazole-based heterocyclic energetic motifs nicely tuned with nitrato (−ONO2) functionality were synthesized by a microwave-assisted environmental friendly synthetic approach with good yields. Thermal stability and the nature of evolved gases on decomposition of structurally characterized energetic motifs were analyzed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis and Fourier transform infrared coupled with TGA–DSC. The explosiveness of these motifs was explored by calculation of enthalpy of formation and density employing density functional theory, and the detonation performances (detonation pressure and velocity) were explored using EXPLO5_V6.03. All of these compounds were calculated to have better oxygen balance (−36 to −52%) as compared to that of trinitrotoluene (−74%). Most of the nitrate ester derivatives were found to exhibit low impact sensitivities, high densities, good thermal stabilities, and promising detonation properties, and PN3 was observed to be a superior candidate in terms of its energetic characteristics. Hence, the experimental and theoretical outcomes strongly reflect that the present approach of developing dendritic high energetic materials bearing green explosive characteristics might be a potential pathway for designing and synthesizing green explosives with desired characteristics.

Formation of small solid particles of micrometer or submicrometer size with controlled particle size distribution is of great interest in applications involving polymers, drugs and energetic materials [1] . In general, the aim of research and development activities in the area of high energy materials (HEMs) is focused on developing energetic materials with improved performance but with reduced sensitivity [2,3] . The focus of research in high explosives has been mainly to synthesize new explosive molecules with the above stated benign properties [4] . However, development through molecular modelling and organic synthesis of novel energetic materials has been very slow and conventional nitramine explosives such as RDX and HMX are still the most commonly used explosives across the globe. Powerful explosives such as CL-20 and octanitrocubane have higher energetic performance than HMX [3,4]. But, sensitivity to accidental stimuli is a matter of concern. The sensitivity of explosives is related to their chemical as well as physical characteristics [5] . Even though development in synthesis of new explosive molecules is small, physical properties such as crystal size, shape, morphology, purity, inclusions, defects in the crystal and the microstructure of inter-crystalline voids can be altered to improve the performance of existing explosives. Thus, crystal engineering offers some prospects for the improvement in performance of energetic materials by controlling some of these physical properties [6]. Theoretical models for the impact initiation of explosives indicate that the sensitivity to external stimuli decreases with decreasing crystal size [5,7] . Some experimental data also supports this theory [8–10] . In addition to significant reduction in sensitivity, novel behavior in deflagration to detonation transition was observed with submicrometersized particles. It is reported in the literature that nanoTATB crystals have higher mass loss than the micro-TATB crystals [11] . Thus, by size reduction of the crystals, sensitivity can be reduced and reactivity can be improved. A few studies have indicated that the particle size of explosives has influence on impact sensitivity and maximum energy output from a detonation [12,13] . However, only limited production strategies are available for making organic nanoparticles in general when compared to the large number of methods available for the preparation of inorganic nanoparticles. Methods used for the preparation of organic nanoparticles are primarily based on either precipitation, milling or through chemical reaction techniques [14]. Submicrometer-sized particles of energetic compounds have been prepared using various techniques such as sol-gel method [15], supercritical fluid methods [16,17] , mechanical milling [18], ultrasonication Abstract : Nanoparticles of cyclotrimethylenetrinitramine (RDX) were prepared by a simple re-precipitation method using acetone as solvent and water as the antisolvent. The effect of changing experimental parameters such as ratio of solvent to antisolvent, temperature of antisolvent during injection and concentration of solution on particle size and morphology of RDX was systematically studied. The size of the particles was characterized using dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM). The mean particle size of the RDX nanoparticles according to FESEM analysis ranged from 40 nm to 230 nm under different conditions of preparation. The UV/Vis absorption maximum of nano-RDX was found to be blue shifted when compared to the absorption maximum for bulk-RDX. Powder X-ray diffraction (XRD) results showed that RDX nanoparticles precipitated in stable a-crystalline form. Fourier transform infrared (FTIR) spectroscopy was used to characterize the chemical nature of the nano-RDX. Thermal characterization of the RDX-nanoparticles was done using simultaneous thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC).

This paper describes formulation of plastic bonded explosives (PBXs) compositions based on 2,4,6- triamino-1,3,5-trinitrobenzene (TATB), Octahydro l,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX) by varying their relative amounts with Viton A as polymeric binder by slurry coating technique. These PBXs compositions are studied for mechanical and detonic properties. It has been observed that sensitivity and explosive performance of PBXs based on mixture of HMX and TATB were varied over a wide considerable range by varying relative amounts of TATB and HMX. The detonation study revealed there was increased in velocity of detonation (VOD) and detonation pressure with increasing amount of HMX from 10-80 % by weight. The sensitivity test results exhibited that insensitivity to impact for PBXs compositions was found to decrease with increasing HMX amount. Friction sensitivity study showed that no reactions were observed upto 36 kg load for PBXs compositions namely HT6030, HT5040, HT4050, HT3060, HT2070 and HT1080. The compressive strength of these PBXs compositions was found within the range of 9-11 MPa. Defence Science Journal, 2013, 63(6), pp.622 -629 , DOI:http://dx.doi.org/10.14429/dsj.63.5764

The process of conversion of a gamma (γ) polymorph of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) to a beta (β) polymorph is a challenging one. In order to obtain beta HMX from gamma HMX, a novel and economical method, using hot water, has been developed. The characterization of beta HMX using thermo-gravimetric and differential thermal analysis, high-performance liquid chromatography (HPLC), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and impact sensitivity has been carried out toward its use for various military applications including advanced propellant formulation.

The IRS-P6 satellite launched by the Indian Space Research Organization (ISRO) is envisaged as a continuity mission of ISRO's earlier spacecraft IRS-1C and IRS-1D, with enhanced capabilities both in the platform and payloads. The orbit determination results for all the Indian Remote Sensing (IRS) satellites of ISRO are obtained by the operational orbit determination software “ISRO-ODP” developed at ISRO Satellite Centre using a batch least squares estimator to process S-band range and range rate measurements. This paper describes the IRS operational orbit determination system and its performance during the initial phase of the mission, and it also highlights the achieved orbit determination accuracy based on two different methods: (1) “difference in position” method, and (2) by presenting the results of an experiment which was designed to ascertain the level of agreement between the ISRO-ODP results and the orbit solutions obtained using tracking data from Global Positioning System.

The first-ever electron momentum density (EMD) measurements of explosive materials, namely, RDX (1,3,5-trinitro-1,3,5-triazacyclohexane, (CH2-N-NO2)3) and HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane, (CH2-N-NO2)4), have been reported using a 740 GBq (137)Cs Compton spectrometer. Experimental Compton profiles (CPs) are compared with the EMDs derived from linear combination of atomic orbitals with density functional theory. It is found that the CPs deduced from generalized gradient approximation (GGA) with Wu-Cohen exchange energies give a better agreement with the corresponding experimental profiles than those from local density approximation and other schemes of GGA. Further, Mulliken population, energy bands, partial and total density of states, and band gap have also been reported using GGA calculations. Present ground state calculations unambiguously show large band gap semiconductor nature of both RDX and HMX. A similar type of bonding in these materials is uniquely established using Compton data and density of states. It is also outstandingly consistent with the Mulliken population, which predicts almost equal amount of charge transfer (0.84 and 0.83 e(-)) from H1 + H2 + N2 to C1 + N1 + O1 + O2 in both the explosives.

Morphology controlled synthesis of nanoparticles of powerful high energetic compounds (HECs) such as 1,3,5-trinitro-1,3,5-triazinane (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) were achieved by a simple solvent–antisolvent interaction (SAI) method at 70 °C. The effects of different solvents on particle size and morphology of the prepared nano-HECs were studied systematically. Particle size and morphology of the nano-HECs was characterized using field emission scanning electron microscopy (FE-SEM) imaging. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy studies revealed that RDX and HMX were precipitated in their most stable polymorphic forms, i.e. α and β, respectively. Thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC) studies showed that the thermal response of the nanoparticles was similar to the respective raw-HECs. HEC nanoparticles with spherical and rod shaped morphology were observed under different solvent conditions. The mean particle size also varied considerably with the use of different solvents.