Highly dispersed copper oxide (CuO) nanoparticles with an average size of 6 nm have been successfully prepared by a novel quick-precipitation method. The as-prepared CuO nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible absorption spectroscopy and BET nitrogen adsorption. The results show that the as-prepared CuO nanoparticles have high dispersion and narrow size distribution. The influence of reaction conditions on morphology of CuO nanocrystals was discussed. Spherical, ellipsoidal and needle-shaped CuO nanocrystals can be obtained simply by varying the reaction temperature and controlling the addition of NaOH.

Highly dispersed CuO nanoparticles prepared by a novel quick-precipitation method

Solid propellants: AP/HTPB composite propellants

Synthesis, characterization and catalytic behavior of Cu nanoparticles on the thermal decomposition of AP, HMX, NTO and composite solid propellants, Part 83

http://www.ndsl.kr/soc_img/society/nuclear/OJRHBJ/2010/v42n6/OJRHBJ_2010_v42n6_636.pdf

The cupid code development and assessment strategy

Preparation of B/Nitrocellulose/Fe particles and their effect on the performance of an ammonium perchlorate propellant

Four transition metal nanoparticles (TMNs) of 3d series (Cu, Co, Ni, and Fe) were prepared by hydrazine reduction of metal chloride in ethylene glycol at 60°C and characterized by X-ray diffraction (XRD). The XRD pattern showed average particle sizes for Cu, Ni, Co, and Fe of 16.7, 40.5, 27.4, and 35.0 nm, respectively. The activity of these TMN accelerants on the thermal decomposition of ammonium perchlorate (AP) was investigated using thermogravimetry (TG), differential scanning calorimetry (DSC), and ignition delay studies. Isothermal TG data were used to evaluate the kinetic parameters by model fitting as well as an isoconversional methods. The activation energy for thermal decomposition of AP was found to be 66.8, 68.7, 78.5, and 85.4 kJmol−1, respectively, for Co, Cu, Ni, and Fe, when they were mixed with AP. Hence, the order of activity was found to be Co > Cu > Ni > Fe. The accelerant effect of nanoparticles of TMNs was found to be better than their respective nano-oxides.

Nanoparticles of Transition Metals as Accelerants in the Thermal Decomposition of Ammonium Perchlorate, Part 62

http://www.koreascience.or.kr:80/article/JAKO201007535004115.pdf

Sampling based uncertainty analysis of 10 % hot leg break loca in large scale test facility

In this study, we have applied computational methods to determine the thermodynamic and explosive characteristics of nitramino derivatives of 1-amino-1,2-azaboriridine. Mono-, di- and tri-nitramino derivatives have been designed and considered for detailed study. Structure optimization and frequency calculation of the species have been performed at DFT-B3LYP/6-311++G(d,p) level of theory. The atomization method is employed to calculate the heat of formation (HOF), using electronic energy data calculated at G3 level. Utilizing the WFA program, crystal densities of designed compounds considered during the present study were predicted using the data obtained at B3PW91/6-31G(d,p) level. Results show that the number of nitramino groups influences the heat of formation of the title compounds. The calculated bond dissociation energies suggest that the N–NO2 bond of the nitramino group is the weakest bond and may be treated as a trigger bond involved in the detonation process. The impact sensitivities (h50) of all the compounds were evaluated and it was found that the designed compound 1-amino-2,3,3-trinitramino-1,2-azaboriridine is highly insensitive towards impact. Theoretical estimate of the condensed phase density of nitramino derivatives was found to be in the range of 1.60–1.80 g cm−3. Detonation velocity (D) and the detonation pressure (P) were found to be 8.0–9.0 km s−1 and 26.2–35.2 GPa, respectively. The present investigation reveals that one of the designed compounds 1-amino-2,3,3-trinitramino-1,2-azaboriridine meets the criteria for high energy density materials.

Computational studies on nitramino derivatives of 1-amino-1,2-azaboriridine as high energetic material

The results of the computational studies performed on 1,2,4-triazolium cation-based salts designed by pairing it with energetic nitro-substituted 5- membered N-heterocyclic anions such as 5-nitrotetrazolate, 3,5-dinitrotriazolate, and 2,4,5 trinitroimidazolate are reported. Condensed phase heats of formation of the designed ionic salts and their thermodynamic and energetic properties have also been calculated. The results show that these salts are potential energetic materials and possess high positive heats of formation. The detonation velocity, D, and detonation pressure, P, have been calculated using the Kamlet-Jacobs equation and found to be 7–8 km/s and 25–29 GPa, respectively. These values fall in the range of the criteria to designate them as high-energy-density materials. Nucleus independent chemical shift (NICS) studies performed on the designed molecules show that these salts are stable in nature.

/pdf/computational-studies-on-1-2-4-triazolium-based-salts-as-3g91hop6f4.pdf

Samiran Sengupta

Papers

Nanoparticles of Transition Metals as Accelerants in the Thermal Decomposition of Ammonium Perchlorate, Part 62

Sampling based uncertainty analysis of 10 % hot leg break loca in large scale test facility

Computational studies on nitramino derivatives of 1-amino-1,2-azaboriridine as high energetic material

Computational studies on 1,2,4-Triazolium-based salts as energetic materials

Sampling Based Uncertainty Analysis of 10% Hot Leg Break LOCA in LSTF