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CreatorTitleDescriptionSubjectDate
1 Voth, Gregory AlanAb initio calculations of reactive pathways for ?-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (?-HMX)Using the BLYP and B3LYP level of density functional theory, four possible decomposition reaction pathways of HMX in the gas phase were investigated: N?NO2 bond dissociation, HONO elimination, C?N bond scission of the ring, and the concerted ring fission. The energetics of each of these four mechan...Ab initio calculations; Reactive pathways; HMX2000
2 Truong, ThanhBranching ratio and pressure dependent rate constants of multichannel unimolecular decomposition of gas-phase ?-HMX: an ab initio dynamics studyThe dynamics of the initial thermal decomposition step of gas-phase ?-HMX is investigated using the master equation method. Both the NO2 fission and HONO elimination channels were considered. The structures, energies, and Hessian information along the minimum energy paths (MEP) of these two channels...Thermal decomposition; HMX2001
3 Orendt, Anita; Pugmire, Ronald J.Carbon-13 chemical shift tensors in polycyclic aromiatic compounds. 9. BiphenyleneThe principal values of the 13C chemical-shift tensors of natural abundance biphenylene were measured at room temperature with the FIREMAT experiment. Of 18 crystallographically distinct positions (three sets of six congruent carbons each), the three primary bands have been resolved into seven singl...Carbon-13; Chemical-shift tensors; Biphenylene; Polycyclic aromiatic compounds; FIREMAT2000
4 Wight, Charles AlbertCompetitive vaporization and decomposition of liquid RDXThe thermal decomposition of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Activation energies as a function of the extent of conversion, ?, have been determined by model-free isoconversional analysis o...Liquid RDX; Competitive vaporization; Thermal decomposition; Differential scanning calorimetry2000
5 Truong, ThanhDirect ab initio dynamics studies of the hydrogen abstraction reactions of hydrogen atom with fluoromethanesA direct ab initio dynamics study on the gas-phase reactions of atomic hydrogen with different fluoromethanes has been carried out. The thermal rate constants were calculated using canonical variational transition state (CVT) theory augmented by multidimensional semiclassical zero and small curvatur...Hydrogen abstraction reactions; Gas-phase reactions; Fluoromethanes; Thermal rate constants; Moller?Plesset perturbation theory; Hybrid density functional theory1999
6 Voth, Gregory AlanElectronic structure calculation of the structures and energies of the three pure polymorphic forms of crystalline HMXThe molecular structures and energetic stabilities of the three pure polymorphic forms of crystalline HMX were calculated using a first-principles electronic-structure method. The computations were performed using the local density approximation in conjunction with localized "fireball" orbitals and ...HMX; Crystalline HMX; Molecular geometry2000
7 Wight, Charles AlbertEstimating realistic confidence intervals for the activation energy determined from thermoanalytical measurementsA statistical procedure is proposed for estimating realistic confidence intervals for the activation energy determined by using an advanced isoconversional method. Nine sets of five thermogravimetric measurements have been produced for the process of gassification of ammonium nitrate at five differe...Thermoanalysis; Activation energy; Isoconversional method2000
8 Truong, ThanhHigh level ab initio and density functional theory evaluation of combustion reaction energetics: NO2 and HONO elimination from dimethylnitramineDimethylnitramine (DMNA) is used as a model system for investigating accurate and efficient electronic structure methods for nitramines. Critical points on the potential energy surfaces of DMNA, CH3NCH3, CH3NCH2, NO2, HONO, and the transition state to HONO elimination were located through geometry o...Dimethylnitramine; DMNA; Nitramines; Combustion reaction energetics1999
9 Truong, ThanhImportance of polarization in simulations of condensed phased energetic materialsAn embedded cluster model is used to estimate the molecular dipole moment of crystalline dimethylnitramine (DMNA). The electrostatic potential due to the crystal is included in the calculation via the SCREEP (surface charge representation of the electrostatic embedding potential) approach. The resul...Dimethylnitramine; DMNA; Embedded cluster model1999
10 Wight, Charles AlbertKinetic study of stabilizing effect of oxygen on thermal degradation of poly(methyl methacrylate)The thermal degradation of poly(methyl methacrylate) (PMMA) has been studied in both pure nitrogen and oxygen-containing atmospheres. The presence of oxygen increases the initial decomposition temperature by 70 °C. The stabilizing effect of oxygen may be explained by forming thermally stable radica...Poly(methyl methacrylate); PMMA; Thermal degradation; Isoconversional method1999
11 Wight, Charles AlbertKinetics of thermal decomposition of cubic ammonium perchlorateThe methods of thermogravimetric analysis (TGA) and differential scanning calorimettry (DSC) have been used to study the thermal decomposition of ammonium perchlorate (AP). TGA curves obtained under both isothermal and nonisothermal conditions show a characteristic slowdown at the extents of convers...Thermal decomposition; Cubic ammonium perchlorate; Differential scanning calorimetry1999
12 Voth, Gregory AlanSystematic coarse-graining of nanoparticle interactions in molecular dynamics simulationA recently developed multiscale coarse-graining procedure [Izvekov, S.; Voth, G. A. J. Phys. Chem. B 2005, 109, 2469] is extended to derive coarse-grained models for nanoparticles. The methodology is applied to C60 and to carbonaceous nanoparticles produced in combustion environments. The coarse-gra...Systematic coarse-graining; Multiscale coarse-graining2005
13 Wight, Charles AlbertThermal activation of the high explosive NTO: sublimation, decomposition, and autocatalysisThermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) show that the heating of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO) leads to competitive sublimation and condensed-phase exothermic decomposition. Model-free isoconversional analysis has determined activation energies...NTO; Thermal activation; Differential scanning calorimetry; Exothermic decomposition; Competitive sublimation2002
14 Wight, Charles AlbertThermal decomposition of a melt-castable high explosive: isoconversional analysis of TNAZThe thermal decomposition kinetics of the high explosive 1,3,3-trinitroazetidine (TNAZ) have been measured by nonisothermal differential scanning calorimetry (DSC). Samples of TNAZ in open pans and pierced pans undergo mainly melting (?Hfus = 27 ± 3 kJ mol-1) and vaporization (?Hvap = 74 ± 10 kJ m...Thermal decomposition; Melt-castable high explosive; TNAZ; Nonisothermal differential scanning calorimetry; Exothermic decomposition2002
15 Wight, Charles AlbertThermal dissociation kinetics of solid and liquid ammonium nitrateThermogravimetry has been used to study the kinetics of the thermal dissociation of solid and liquid ammonium nitrate. Model-fitting and model-free kinetic methods have been applied to the sets of isothermal and nonisothermal measurements to derive kinetic characteristics of the processes. The appli...Thermal dissociation kinetics2001
16 Truong, ThanhThermal rate constants of the NO2 fission reaction of gas phase ?-HMX: a direct ab initio dynamics studyThe NO2 fission reaction of gas phase ?-HMX has been studied using a direct ab initio method within the framework of microcanonical variational transition state theory (?VT). The potential energy calculations were calculated using the hybrid nonlocal B3LYP density functional theory with the cc-pVDZ ...HMX; Fission reaction; Thermal rate constants; Microcanonical variational transition state theory2000
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