Molecular Dynamics Simulations on the solvation and interfacial behaviour of hydrophobic species. Applications to the TATB hypothesis and to the liquid/liquid extraction of cations to supercritical CO2

International Nuclear Information System (INIS)

Schurhammer, R.

2001-12-01

We report molecular dynamics studies on the solvation of charged hydrophobic molecules in pure liquids and at liquid / liquid interfaces. The first part of the thesis deals with the TATB hypothesis according to which the Asφ 4 + (TA + ) and Bφ 4 - (TB - ) ions have the same free energy of solvation in any solvent. The two ions are found to be solvated differently in pure liquids (water, chloroform, acetonitrile) as at a chloroform / water interface. These results are confirmed by free energy calculations and by simulations on iso-volume spherical S + and S - ions, which perfectly meet the TATB criteria. The many methodological tests performed show the importance of (i) the corrected treatment of 'long range interactions' (ii) the precise repartition of atomic charges (iii) the solvent models, especially for water, on the + / - charge discrimination by solvent. In the second part, in relation to the liquid / liquid extraction of cations from water to supercritical CO 2 , we report the behaviour of ions (Cs + , UO 2 2+ , Eu 3+ ), of un-complexed extractants molecules (tri-n-butylphosphate, calixarene), of their complexes with the cations and nitric acid at a preformed chloroform / water interface and during de-mixing simulations which started from a perfectly mixed CO 2 / water solutions. These studies demonstrate the importance of interfacial phenomena, of simulation conditions and acid and extractant concentrations, in assisted ion extraction to supercritical CO 2 . (author)

Molecular Dynamics Simulations on the solvation and interfacial behaviour of hydrophobic species. Applications to the TATB hypothesis and to the liquid/liquid extraction of cations to supercritical CO{sub 2}; Simulations par dynamique moleculaire de la solvatation et du comportement interfacial d'especes hydrophobes: application a l'hypothese TATB et a l'extraction liquide/liquide de cations par le CO{sub 2} supercritique

Energy Technology Data Exchange (ETDEWEB)

Schurhammer, R

2001-12-15

We report molecular dynamics studies on the solvation of charged hydrophobic molecules in pure liquids and at liquid / liquid interfaces. The first part of the thesis deals with the TATB hypothesis according to which the As{phi}{sub 4}{sup +} (TA{sup +}) and B{phi}{sub 4}{sup -} (TB{sup -}) ions have the same free energy of solvation in any solvent. The two ions are found to be solvated differently in pure liquids (water, chloroform, acetonitrile) as at a chloroform / water interface. These results are confirmed by free energy calculations and by simulations on iso-volume spherical S{sup +} and S{sup -} ions, which perfectly meet the TATB criteria. The many methodological tests performed show the importance of (i) the corrected treatment of 'long range interactions' (ii) the precise repartition of atomic charges (iii) the solvent models, especially for water, on the + / - charge discrimination by solvent. In the second part, in relation to the liquid / liquid extraction of cations from water to supercritical CO{sub 2}, we report the behaviour of ions (Cs{sup +}, UO{sub 2}{sup 2+}, Eu{sup 3+}), of un-complexed extractants molecules (tri-n-butylphosphate, calixarene), of their complexes with the cations and nitric acid at a preformed chloroform / water interface and during de-mixing simulations which started from a perfectly mixed CO{sub 2} / water solutions. These studies demonstrate the importance of interfacial phenomena, of simulation conditions and acid and extractant concentrations, in assisted ion extraction to supercritical CO{sub 2}. (author)

Evolution of Carbon Clusters in the Detonation Products of the Triaminotrinitrobenzene (TATB)-Based Explosive PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Watkins, Erik B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Velizhanin, Kirill A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Dattelbaum, Dana M. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Gustavsen, Richard L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Aslam, Tariq D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Podlesak, David W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Huber, Rachel C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Firestone, Millicent A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Ringstrand, Bryan S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States; Willey, Trevor M. [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; Bagge-Hansen, Michael [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; Hodgin, Ralph [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; Lauderbach, Lisa [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; van Buuren, Tony [Lawrence Livermore National Laboratory, Livermore, California 94550, United States; Sinclair, Nicholas [Washington State University, Pullman, Washington 99164, United States; Rigg, Paulo A. [Washington State University, Pullman, Washington 99164, United States; Seifert, Soenke [Argonne National Laboratory, Lemont, Illinois 60439, United States; Gog, Thomas [Argonne National Laboratory, Lemont, Illinois 60439, United States

2017-10-05

The detonation of carbon-rich high explosives yields solid carbon as a major constituent of the product mixture and, depending on the thermodynamic conditions behind the shock front, a variety of carbon allotropes and morphologies may form and evolve. We applied time-resolved small angle x-ray scattering (TR-SAXS) to investigate the dynamics of carbon clustering during detonation of PBX 9502, an explosive composed of triaminotrinitrobenzene (TATB) and 5 wt% fluoropolymer binder. Solid carbon formation was probed from 0.1 to 2.0 μs behind the detonation front and revealed rapid carbon cluster growth which reached a maximum after ~200 ns. The late-time carbon clusters had a radius of gyration of 3.3 nm which is consistent with 8.4 nm diameter spherical particles and matched particle sizes of recovered products. Simulations using a clustering kinetics model were found to be in good agreement with the experimental measurements of cluster growth when invoking a freeze-out temperature, and temporal shift associated with the initial precipitation of solid carbon. Product densities from reactive flow models were compared to the electron density contrast obtained from TR-SAXS and used to approximate the carbon cluster composition as a mixture of 20% highly ordered (diamond-like) and 80% disordered carbon forms, which will inform future product equation of state models for solid carbon in PBX 9502 detonation product mixtures.

Shock Initiation of Wedge-shaped Explosive Measured with Smear Camera and Photon Doppler Velocimetry

Science.gov (United States)

Gu, Yan

2017-06-01

Triaminotrinitrobenzene (TATB) is an important insensitive high explosive in conventional weapons due to its safety and high energy. In order to have an insight into the shock initiation performance of a TATB-based insensitive high explosive (IHE), experimental measurements of the particle velocity histories of the TATB-based Explosive using Photon Doppler Velocimetry and shock wave profile of the TATB-based explosive using High Speed Rotating Mirror Smear Camera had been performed. In this paper, we would describe the shock initiation performance of the TATB-based explosive by run-to-detonation distance and the particle velocity history at an initialization shock of about 7.9 GPa. The parameters of hugoniot of unreacted the TATB-based explosive and Pop relationship could be derived with the particle velocity history obtained in this paper.

Nitrogen-rich heterocycles as reactivity retardants in shocked insensitive explosives.

Science.gov (United States)

Manaa, M Riad; Reed, Evan J; Fried, Laurence E; Goldman, Nir

2009-04-22

We report the first quantum-based multiscale simulations to study the reactivity of shocked perfect crystals of the insensitive energetic material triaminotrinitrobenzene (TATB). Tracking chemical transformations of TATB experiencing overdriven shock speeds of 9 km/s for up to 0.43 ns and 10 km/s for up to 0.2 ns reveal high concentrations of nitrogen-rich heterocyclic clusters. Further reactivity of TATB toward the final decomposition products of fluid N(2) and solid carbon is inhibited due to the formation of these heterocycles. Our results thus suggest a new mechanism for carbon-rich explosive materials that precedes the slow diffusion-limited process of forming the bulk solid from carbon clusters and provide fundamental insight at the atomistic level into the long reaction zone of shocked TATB.

Carbon cluster formation during thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine and 1,3,5-triamino-2,4,6-trinitrobenzene high explosives from ReaxFF reactive molecular dynamics simulations.

Science.gov (United States)

Zhang, Luzheng; Zybin, Sergey V; van Duin, Adri C T; Dasgupta, Siddharth; Goddard, William A; Kober, Edward M

2009-10-08

We report molecular dynamics (MD) simulations using the first-principles-based ReaxFF reactive force field to study the thermal decomposition of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) at various densities and temperatures. TATB is known to produce a large amount (15-30%) of high-molecular-weight carbon clusters, whereas detonation of nitramines such as HMX and RDX (1,3,5-trinitroperhydro-1,3,5-triazine) generate predominantly low-molecular-weight products. In agreement with experimental observation, these simulations predict that TATB decomposition quickly (by 30 ps) initiates the formation of large carbonaceous clusters (more than 4000 amu, or approximately 15-30% of the total system mass), and HMX decomposition leads almost exclusively to small-molecule products. We find that HMX decomposes readily on this time scale at lower temperatures, for which the decomposition rate of TATB is about an order of magnitude slower. Analyzing the ReaxFF MD results leads to the detailed atomistic structure of this carbon-rich phase of TATB and allows characterization of the kinetics and chemistry related to this phase and their dependence on system density and temperature. The carbon-rich phase formed from TATB contains mainly polyaromatic rings with large oxygen content, leading to graphitic regions. We use these results to describe the initial reaction steps of thermal decomposition of HMX and TATB in terms of the rates for forming primary and secondary products, allowing comparison to experimentally derived models. These studies show that MD using the ReaxFF reactive force field provides detailed atomistic information that explains such macroscopic observations as the dramatic difference in carbon cluster formation between TATB and HMX. This shows that ReaxFF MD captures the fundamental differences in the mechanisms of such systems and illustrates how the ReaxFF may be applied to model complex chemical phenomena

Effects of altered TatC proteins on protein secretion efficiency via the twin-arginine translocation pathway of Bacillus subtilis

NARCIS (Netherlands)

Eijlander, Robyn T.; Kolbusz, Magdalena A.; Berendsen, Erwin M.; Kuipers, Oscar P.

Protein translocation via the Tat machinery in thylakoids and bacteria occurs through a cooperation between the TatA, TatB and TatC subunits, of which the TatC protein forms the initial Tat substrate-binding site. The Bacillus subtilis Tat machinery lacks TatB and comprises two separate TatAC

Vicarious nucleophilic substitution to prepare 1,3-diamino-2,4,6-trinitrobenzene or 1,3,5-triamino-2,4,6-trinitrobenzene

Science.gov (United States)

Mitchell, Alexander R.; Pagoria, Philip F.; Schmidt, Robert D.

1996-01-01

The present invention relates to a process to produce 1,3-diamino-2,4,6-trinitrobenzene (DATB) or 1,3,5-triamino-2,4,6,-trinitrobenzene (TATB) by: (a) reacting at ambient pressure and a temperature of between about 0.degree. and 50.degree. C. for between about 0.1 and 24 hr, a trinitroaromatic compound of structure V: ##STR1## wherein X, Y, and Z are each independently selected from --H, or --NH.sub.2, with the proviso that at least 1 or 2 of X, Y, and Z are hydrogen, with an amount effective to produce DATB or TATB of 1,1,1-trialkylhydrazinium halide wherein alkyl is selected from methyl, ethyl, propyl or butyl and halide is selected from chloride, bromide or iodide. in the presence of a strong base selected from sodium butoxide, potassium butoxide, potassium propoxide, sodium propoxide, sodium ethoxide, potassium ethoxide, sodium methoxide, potassium methoxide, and combinations thereof; in a solvent selected from the group consisting of methanol, ethanol, propanol, butanol, dimethylsulphoxide, N-methylpyrrolidone, hexamethylphosphoramide, dimethylformide, dimethylacetamide and mixtures thereof, provided that when alcohols are present primarily DATB and picramide is formed; and (b) isolating the DATB or TATB produced. DATB and TATB are useful specialty explosives. TATB is also used for the preparation of benzenehexamine, a starting material for the synthesis of novel materials (optical imaging devices, liquid crystals, ferromagnetic compounds).

Literature Review on Demilitarization of Munitions: Document Prepared for the RIGHTTRAC Technology Demonstration Project

Science.gov (United States)

2010-11-01

11 Figure 5: Atkins synthesis of TATB from TNT [64] .................................................................... 31 Figure 6...e.g., lead azide or metal fulminates ) are generally not good candidates for recovery and reuse due to their sensitivity [16] and the small amount of...iii) no interference with night-vision devices [96]. The system is still at the prototype development level [1]. 3.3.2.2.5 Synthesis of TATB

Metal-Organic Framework of Lanthanoid Dinuclear Clusters Undergoes Slow Magnetic Relaxation

Directory of Open Access Journals (Sweden)

Hikaru Iwami

2017-01-01

Full Text Available Lanthanoid metal-organic frameworks (Ln-MOFs can adopt a variety of new structures due to the large coordination numbers of Ln metal ions, and Ln-MOFs are expected to show new luminescence and magnetic properties due to the localized f electrons. In particular, some Ln metal ions, such as Dy(III and Tb(III ions, work as isolated quantum magnets when they have magnetic anisotropy. In this work, using 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB as a ligand, two new Ln-MOFs, [Dy(TATB(DMF2] (1 and [Tb(TATB(DMF2] (2, were obtained. The Ln-MOFs contain Ln dinuclear clusters as secondary building units, and 1 underwent slow magnetic relaxation similar to single-molecule magnets.

SURFplus Model Calibration for PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-12-06

The SURFplus reactive burn model is calibrated for the TATB based explosive PBX 9502 at three initial temperatures; hot (75 C), ambient (23 C) and cold (-55 C). The CJ state depends on the initial temperature due to the variation in the initial density and initial specific energy of the PBX reactants. For the reactants, a porosity model for full density TATB is used. This allows the initial PBX density to be set to its measured value even though the coeffcient of thermal expansion for the TATB and the PBX differ. The PBX products EOS is taken as independent of the initial PBX state. The initial temperature also affects the sensitivity to shock initiation. The model rate parameters are calibrated to Pop plot data, the failure diameter, the limiting detonation speed just above the failure diameters, and curvature effect data for small curvature.

Composting of soils/sediments and sludges containing toxic organics including high energy explosives. Final report

Energy Technology Data Exchange (ETDEWEB)

Doyle, R.C.; Kitchens, J.F.

1993-07-01

Laboratory and pilot-scale experimentation were conducted to evaluate composting as an on-site treatment technology to remediate soils contaminated with hazardous waste at DOE`s PANTEX Plant. Suspected contaminated sites within the PANTEX Plant were sampled and analyzed for explosives, other organics, and inorganic wastes. Soils in drainage ditches and playas at PANTEX Plant were found to be contaminated with low levels of explosives (including RDX, HMX, PETN and TATB). Additional sites previously used for solvent disposal were heavily contaminated with solvents and transformation products of the solvent, as well as explosives and by-products of explosives. Laboratory studies were conducted using {sup 14}C-labeled explosives and {sup 14}C-labeled diacetone alcohol contaminated soil loaded into horse manure/hay composts at three rates: 20, 30, and 40%(W/W). The composts were incubated for six weeks at approximately 60{degree}C with continuous aeration. All explosives degraded rapidly and were reduced to below detection limits within 3 weeks in the laboratory studies. {sup 14}C-degradates from {sup 14}C-RDX, {sup 14}C-HMX and {sup 14}C-TATB were largely limited to {sup 14}CO{sub 2} and unextracted residue in the compost. Volatile and non-volatile {sup 14}C-degradates were found to result from {sup 14}C-PETN breakdown, but these compounds were not identified. {sup 14}C-diacetone alcohol concentrations were significantly reduced during composting. However, most of the radioactivity was volatilized from the compost as non-{sup 14}CO{sub 2} degradates or as {sup 14}C-diacetone alcohol. Pilot scale composts loaded with explosives contaminated soil at 30% (W/W) with intermittent aeration were monitored over six weeks. Data from the pilot-scale study generally was in agreement with the laboratory studies. However, the {sup 14}C-labeled TATB degraded much faster than the unlabeled TATB. Some formulations of TATB may be more resistant to composting activity than others.

Understanding the scale of the single ion free energy: A critical test of the tetra-phenyl arsonium and tetra-phenyl borate assumption

Science.gov (United States)

Duignan, Timothy T.; Baer, Marcel D.; Mundy, Christopher J.

2018-06-01

The tetra-phenyl arsonium and tetra-phenyl borate (TATB) assumption is a commonly used extra-thermodynamic assumption that allows single ion free energies to be split into cationic and anionic contributions. The assumption is that the values for the TATB salt can be divided equally. This is justified by arguing that these large hydrophobic ions will cause a symmetric response in water. Experimental and classical simulation work has raised potential flaws with this assumption, indicating that hydrogen bonding with the phenyl ring may favor the solvation of the TB- anion. Here, we perform ab initio molecular dynamics simulations of these ions in bulk water demonstrating that there are significant structural differences. We quantify our findings by reproducing the experimentally observed vibrational shift for the TB- anion and confirm that this is associated with hydrogen bonding with the phenyl rings. Finally, we demonstrate that this results in a substantial energetic preference of the water to solvate the anion. Our results suggest that the validity of the TATB assumption, which is still widely used today, should be reconsidered experimentally in order to properly reference single ion solvation free energy, enthalpy, and entropy.

Propagation of Axially Symmetric Detonation Waves

Energy Technology Data Exchange (ETDEWEB)

Druce, R L; Roeske, F; Souers, P C; Tarver, C M; Chow, C T S; Lee, R S; McGuire, E M; Overturf, G E; Vitello, P A

2002-06-26

We have studied the non-ideal propagation of detonation waves in LX-10 and in the insensitive explosive TATB. Explosively-driven, 5.8-mm-diameter, 0.125-mm-thick aluminum flyer plates were used to initiate 38-mm-diameter, hemispherical samples of LX-10 pressed to a density of 1.86 g/cm{sup 3} and of TATB at a density of 1.80 g/cm{sup 3}. The TATB powder was a grade called ultrafine (UFTATB), having an arithmetic mean particle diameter of about 8-10 {micro}m and a specific surface area of about 4.5 m{sup 2}/g. Using PMMA as a transducer, output pressure was measured at 5 discrete points on the booster using a Fabry-Perot velocimeter. Breakout time was measured on a line across the booster with a streak camera. Each of the experimental geometries was calculated using the Ignition and Growth Reactive Flow Model, the JWL++ Model and the Programmed Burn Model. Boosters at both ambient and cold (-20 C and -54 C) temperatures have been experimentally and computationally studied. A comparison of experimental and modeling results is presented.

300 K Isothermal Equations of State of DADNE, DNAN, and LX-17

Science.gov (United States)

Zaug, Joseph; Stavrou, Elissaios; Grivickas, Paulius; Pagoria, Phil; Hansen, Donald; Gagliardi, Franco; Sain, John; Bastea, Sorin

2017-06-01

Using a direct optical-based measurement approach, we report 10 GPa scale, 300 K isothermal equations of state (EOS) of single crystal 1,1-Diamino-2,2-dinitroethylene (DADNE, FOX-7), single crystal 2,4, Dintrosoanisole (DNAN) and a polymer blended explosive (PBX) composite LX-17 (92.5% triamino trinitro benzene (TATB), and 7.5% KEL-F 800). Results from quasi-statically compressed LX-17 represent the first-ever isothermal EOS measurements of a PBX. Recently, we published a paper outlining the utility of using in-house optical microscopy and interferometry (OMI) diagnostics to directly measure pressure dependent sample volumes of single crystals TATB and alpha-NTO compressed within diamond-anvil cell sample chambers. (Our TATB OMI results agree remarkably well with two independent powder x-ray diffraction EOS studies.) In addition, here we report single crystal pressure dependent indices of refraction from DADNE that clearly signal the onset of electronic and/or molecular (structural) transitions that are otherwise indistinguishable in 300 K plotted pressure-volume EOS isotherms. EOS model parameters are reported from weighted and unweighted fits to the OMI experimental data. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Flexible long-chain-linker constructed Ni-based metal-organic frameworks with 1D helical channel and their pseudo-capacitor behavior studies

Science.gov (United States)

Wang, Kuaibing; Wang, Zikai; Wang, Xin; Zhou, Xueqin; Tao, Yuehong; Wu, Hua

2018-02-01

Two novel and isostructural Ni-based MOFs with topological symbol of 422·54·62, namely [Ni2(TATB)2(L)2(H2O)], have successfully synthesized, where L is the flexibly N-donor bid (1,10-bisimidazoledecane) or btd (1,10-bistriazoledecane) linker and TATB is the deprotonation mode from 4,4‧,4″-s-triazine-2,4,6-triyl-tribenzoic acid (H3TATB). Two types of left- and right-handed helical channels with mean diameter of 11 Å results in large void space in 3D network. When directly use as electrode materials, the as-synthesized Ni-MOFs single-crystal electrodes behave as pseudo-capacitor and deliver high gravimetric capacitance with superior energy deliverable ability and cycling stability. For example, the maximum gravimetric capacitance is 705 F g-1 with the energy density of 29.6 Wh kg-1 at a current density of 1 A g-1. Even after 5000 continuous cycles, the capacitance retention maintains at 92.1%. The good electrochemical performance should be ascribed to the 1D helical channels facilitating the diffusion of OH-. Furthermore, the low bulk solution (0.46 and 0.50 Ω) and charge-transfer resistances accelerate the contact between OH- and active species in the electrode, and consequently result in efficiency Faradaic reaction. This work opens a new way for the directly application of 3D topological MOFs single-crystal with novel interior structures especially porous and channel-like architectures in electronic energy storage field.

A novel method for the measurement of the von Neumann spike in detonating high explosives

Science.gov (United States)

Sollier, A.; Bouyer, V.; Hébert, P.; Doucet, M.

2016-06-01

We present detonation wave profiles measured in T2 (97 wt. % TATB) and TX1 (52 wt. % TATB and 45 wt. % HMX) high explosives. The experiments consisted in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. Free surface velocity wave profiles were measured at the explosive/air interface using a Photon Doppler Velocimetry system. We demonstrate that a comparison of these free surface wave profiles with those measured at explosive/window interfaces in similar conditions allows to bracket the von Neumann spike in a narrow range. For T2, our measurements show that the spike pressure lies between 35.9 and 40.1 GPa, whereas for TX1, it lies between 42.3 and 47.0 GPa. The numerical simulations performed in support to these measurements show that they can be used to calibrate reactive burn models and also to check the accuracy of the detonation products equation of state at low pressure.

High-nitrogen explosives

Energy Technology Data Exchange (ETDEWEB)

Naud, D. (Darren); Hiskey, M. A. (Michael A.); Kramer, J. F. (John F.); Bishop, R. L. (Robert L.); Harry, H. H. (Herbert H.); Son, S. F. (Steven F.); Sullivan, G. K. (Gregg K.)

2002-01-01

The syntheses and characterization of various tetrazine and furazan compounds offer a different approach to explosives development. Traditional explosives - such as TNT or RDX - rely on the oxidation of the carbon and hydrogen atoms by the oxygen carrying nitro group to produce the explosive energy. High-nitrogen compounds rely instead on large positive heats of formation for that energy. Some of these high-nitrogen compounds have been shown to be less sensitive to initiation (e.g. by impact) when compared to traditional nitro-containing explosives of similar performances. Using the precursor, 3,6-bis-(3,5-dimethylpyrazol-1-yl)-s-tetrazine (BDT), several useful energetic compounds based on the s-tetrazine system have been synthesized and studied. The compound, 3,3{prime}-azobis(6-amino-s-tetrazine) or DAAT, detonates as a half inch rate stick despite having no oxygen in the molecule. Using perfluoroacetic acid, DAAT can be oxidized to give mixtures of N-oxide isomers (DAAT03.5) with an average oxygen content of about 3.5. This energetic mixture burns at extremely high rates and with low dependency on pressure. Another tetrazine compound of interest is 3,6-diguanidino-s-tetrazine(DGT) and its dinitrate and diperchlorate salts. DGT is easily synthesized by reacting BDT with guanidine in methanol. Using Caro's acid, DGT can be further oxidized to give 3,6-diguanidino-s-tetrazine-1,4-di-N-oxide (DGT-DO). Like DGT, the di-N-oxide can react with nitric acid or perchloric acid to give the dinitrate and the diperchlorate salts. The compounds, 4,4{prime}-diamino-3,3{prime}-azoxyfurazan (DAAF) and 4,4{prime}-diamino-3,3{prime}-azofurazan (DAAzF), may have important future roles in insensitive explosive applications. Neither DAAF nor DAAzF can be initiated by laboratory impact drop tests, yet both have in some aspects better explosive performances than 1,3,5-triamino-2,4,6-trinitrobenzene TATB - the standard of insensitive high explosives. The thermal stability of DAAz

Shock temperature dependent rate law for plastic bonded explosives

Science.gov (United States)

Aslam, Tariq D.

2018-04-01

A reactive flow model for the tri-amino-tri-nitro-benzene (TATB) based plastic bonded explosive PBX 9502 (95% TATB, 5% polymeric binder Kel-F 800) is presented. This newly devised model is based primarily on the shock temperature of the material, along with local pressure, and accurately models a broader range of detonation and initiation scenarios. Specifically, sensitivity changes to the initial explosive temperature are accounted for naturally and with a single set of parameters. The equation of state forms for the reactants and products, as well as the thermodynamic closure of pressure and temperature equilibration, are carried over from the Wescott-Stewart-Davis (WSD) model [Wescott et al., J. Appl. Phys. 98, 053514 (2005) and "Modeling detonation diffraction and dead zones in PBX-9502," in Proceedings of the Thirteenth International Detonation Symposium (2006)]. This newly devised model, with Arrhenius state dependence on the shock temperature, based on the WSD equation of states, is denoted by AWSD. Modifying an existing implementation of the WSD model to the AWSD model in a hydrocode is a rather straightforward procedure.

Porous anionic indium-organic framework with enhanced gas and vapor adsorption and separation ability.

Science.gov (United States)

Huang, Yuanbiao; Lin, Zujin; Fu, Hongru; Wang, Fei; Shen, Min; Wang, Xusheng; Cao, Rong

2014-09-01

A three-dimensional microporous anionic metal-organic framework (MOF) (Et4N)3[In3(TATB)4] (FJI-C1, H3TATB=4,4',4''-s-triazine-2,4,6-triyltribenzoic acid) with large unit cell volume has been synthesized. Assisted by the organic cation group Et4N in the pores of the compound, FJI-C1 not only shows high adsorption uptakes of C2 and C3 hydrocarbons, but also exhibits highly selective separation of propane, acetylene, ethane, and ethylene from methane at room temperature. Furthermore, it also exhibits high separation selectivity for propane over C2 hydrocarbons and acetylene can be readily separated from their C2 hydrocarbons mixtures at low pressure due to the high selectivity for C2H2 in comparison to C2H4 and C2H6. In addition, FJI-C1 with hydrophilic internal pores surfaces shows highly efficient adsorption separation of polar molecules from nonpolar molecules. Notably, it exhibits high separation selectivity for benzene over cyclohexane due to the π-π interactions between benzene molecules and s-triazine rings of the porous MOF. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Manufacture of TATB and TNT from Biosynthesized Phloroglucinols

Science.gov (United States)

2010-07-01

calculated for C7H5N3O9: C, 30.56; H, 1.83; N, 15.27. Found: C, 30.12; H, 1.54; N, 14.83. Slow diffusion of n-heptane into a chloroform solution of 2...2.1 g, 91% yield) as a slow crystallizing yellow oil. 1H NMR (CDCl3) δ 0.94 (t, 3H, propyl CH3), 1.73 (m, 3H, propyl CH2), 4.02 (s, 6H, O-CH3), 4.10...t, 2H, propyl CH2); 13C NMR (CDCl3) δ 9.78, 23.14, 64.48, 79.68, 135.55, 26 135,99, 146.68, 147.19. Elemental analysis calculated for C11H13N3O9: C

Molten salt destruction as an alternative to open burning of energetic material wastes

International Nuclear Information System (INIS)

Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.; Brummond, W.A.

1994-01-01

LLNL has built a small-scale (about 1 kg/hr throughput unit to test the destruction of energetic materials using the Molten Salt Destruction (MSD) process. We have modified the unit described in the earlier references to inject energetic waste material continuously into the unit. In addition to the HMX, other explosives we have destroyed include RDX, PETN, ammonium picrate, TNT, nitroguanadine, and TATB. We have also destroyed a liquid gun propellant comprising hydroxyl ammonium nitrate, triethanolammonium nitrate and water. In addition to these pure components, we have destroyed a number of commonly used formulations, such as LX-10 (HMX/Viton), LX-16 (PETN/FPC461, LX-17 (TATB/Kel F), and PBX-9404 (HMX)/CEF/Nitro cellulose). Our experiments have demonstrated that energetic materials can be safely and effectively treated by MSD.We have also investigated the issue of steam explosions in molten salt units, both experimentally and theoretically, and concluded that steam explosions can be avoided under proper design and operating conditions. We are currently building a larger unit (nominal capacity 5 kg/hr,) to investigate the relationship between residence time, temperature, feed concentration and throughputs, avoidance of back-burn, a;nd determination of the products of combustion under different operating conditions

miR156-Targeted SBP-Box Transcription Factors Interact with DWARF53 to Regulate TEOSINTE BRANCHED1 and BARREN STALK1 Expression in Bread Wheat.

Science.gov (United States)

Liu, Jie; Cheng, Xiliu; Liu, Pan; Sun, Jiaqiang

2017-07-01

Genetic and environmental factors affect bread wheat ( Triticum aestivum ) plant architecture, which determines grain yield. In this study, we demonstrate that miR156 controls bread wheat plant architecture. We show that overexpression of tae-miR156 in bread wheat cultivar Kenong199 leads to increased tiller number and severe defects in spikelet formation, probably due to the tae-miR156-mediated repression of a group of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE ( SPL ) genes. Furthermore, we found that the expression of two genes TEOSINTE BRANCHED1 ( TaTB1 ) and BARREN STALK1 ( TaBA1 ), whose orthologous genes in diverse plant species play conserved roles in regulating plant architecture, is markedly reduced in the tae-miR156-OE bread wheat plants. Significantly, we demonstrate that the strigolactone (SL) signaling repressor DWARF53 (TaD53), which physically associates with the transcriptional corepressor TOPLESS, can directly interact with the N-terminal domains of miR156-controlled TaSPL3/17. Most importantly, TaSPL3/17-mediated transcriptional activation of TaBA1 and TaTB1 can be largely repressed by TaD53 in the transient expression system. Our results reveal potential association between miR156-TaSPLs and SL signaling pathways during bread wheat tillering and spikelet development. © 2017 American Society of Plant Biologists. All Rights Reserved.

Failure Diameter Resolution Study

Energy Technology Data Exchange (ETDEWEB)

Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-12-19

Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

A Recipe for implementing the Arrhenius-Shock-Temperature State Sensitive WSD (AWSD) model, with parameters for PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Aslam, Tariq Dennis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-03

A reactive ow model for the tri-amino-tri-nitro-benzene (TATB) based plastic bonded explosive PBX 9502 is presented. This newly devised model is based primarily on the shock temperature of the material, along with local pressure, and accurately models a broader range of detonation and initiation scenarios. The equation of state for the reactants and products, as well as the thermodynamic closure of pressure and temperature equilibration are carried over from the Wescott-Stewart-Davis (WSD) model7,8. Thus, modifying an existing WSD model in a hydrocode should be rather straightforward.

Structural basis for TatA oligomerization: an NMR study of Escherichia coli TatA dimeric structure.

Directory of Open Access Journals (Sweden)

Yi Zhang

Full Text Available Many proteins are transported across lipid membranes by protein translocation systems in living cells. The twin-arginine transport (Tat system identified in bacteria and plant chloroplasts is a unique system that transports proteins across membranes in their fully-folded states. Up to date, the detailed molecular mechanism of this process remains largely unclear. The Escherichia coli Tat system consists of three essential transmembrane proteins: TatA, TatB and TatC. Among them, TatB and TatC form a tight complex and function in substrate recognition. The major component TatA contains a single transmembrane helix followed by an amphipathic helix, and is suggested to form the translocation pore via self-oligomerization. Since the TatA oligomer has to accommodate substrate proteins of various sizes and shapes, the process of its assembly stands essential for understanding the translocation mechanism. A structure model of TatA oligomer was recently proposed based on NMR and EPR observations, revealing contacts between the transmembrane helices from adjacent subunits. Herein we report the construction and stabilization of a dimeric TatA, as well as the structure determination by solution NMR spectroscopy. In addition to more extensive inter-subunit contacts between the transmembrane helices, we were also able to observe interactions between neighbouring amphipathic helices. The side-by-side packing of the amphipathic helices extends the solvent-exposed hydrophilic surface of the protein, which might be favourable for interactions with substrate proteins. The dimeric TatA structure offers more detailed information of TatA oligomeric interface and provides new insights on Tat translocation mechanism.

An approach to incorporate the detonation shock dynamics into the calculation of explosive acceleration of metals

International Nuclear Information System (INIS)

Li Qingzhong; Sun Chengwei; Zhao Feng; Gao Wen; Wen Shanggang; Liu Wenhan

1999-11-01

The generalized geometrical optics model for the detonation shock dynamics (DSD) has been incorporated into the two dimensional hydro-code WSU to form a combination code ADW for numerical simulation of explosive acceleration of metals. An analytical treatment of the coupling conditions at the nodes just behind the detonation front is proposed. The experiments on two kinds of explosive-flyer assemblies with different length/diameter ratio were carried out to verify the ADW calculations, where the tested explosive was HMX or TATB based. It is found that the combination of DSD and hydro-code can improve the calculation precision, and has advantages in larger meshes and less CPU time

Science & Technology Review June 2009

Energy Technology Data Exchange (ETDEWEB)

Bearinger, J P

2009-06-05

This month's issue has the following articles: (1) A Safer and Even More Effective TATB - Commentary by Bruce T. Goodwin; (2) Dissolving Molecules to Improve Their Performance - Computer scientists and chemists have teamed to develop a green method for recycling a valuable high explosive that is no longer manufactured; (3) Exceptional People Producing Great Science - Postdoctoral researchers lend their expertise to projects that support the Laboratory's missions; (4) Revealing the Identities and Functions of Microbes - A new imaging technique illuminates bacterial metabolic pathways and complex relationships; and (5) A Laser Look inside Planets - Laser-driven ramp compression may one day reveal the interior structure of Earth-like planets in other solar systems.

Development of a ReaxFF reactive force field for ammonium nitrate and application to shock compression and thermal decomposition.

Science.gov (United States)

Shan, Tzu-Ray; van Duin, Adri C T; Thompson, Aidan P

2014-02-27

We have developed a new ReaxFF reactive force field parametrization for ammonium nitrate. Starting with an existing nitramine/TATB ReaxFF parametrization, we optimized it to reproduce electronic structure calculations for dissociation barriers, heats of formation, and crystal structure properties of ammonium nitrate phases. We have used it to predict the isothermal pressure-volume curve and the unreacted principal Hugoniot states. The predicted isothermal pressure-volume curve for phase IV solid ammonium nitrate agreed with electronic structure calculations and experimental data within 10% error for the considered range of compression. The predicted unreacted principal Hugoniot states were approximately 17% stiffer than experimental measurements. We then simulated thermal decomposition during heating to 2500 K. Thermal decomposition pathways agreed with experimental findings.

The synthesis of di(aminoguanidine) 5-nitroiminotetrazolate: some diprotic or monoprotic acids as precursors of energetic salts.

Science.gov (United States)

Gao, Haixiang; Huang, Yangen; Ye, Chengfeng; Twamley, Brendan; Shreeve, Jean'ne M

2008-01-01

Syntheses of salts with 4,6-bis(nitroimino)-1,3,5-triazinan-2-one (DNAM), 3,5-dinitro-1,2,4-cyclopentanetrione (DDCP), 3-nitroiminotriazolate, and 5-nitroiminotetrazolate as anions yielded moderately dense nitro-containing energetic salts that are thermally stable to >200 degrees C (measured by thermogravimetric analysis). Di(aminoguanidine) 5-nitroiminotetrazolate (8) crystallizes in the monoclinic space group P2(1)/c with an essentially planar 5-nitroiminotetrazolate dianion. Based on experimental and calculated densities, and theoretical calculations carried out by using the Gaussian 03 suite of programs, all of the salts have calculated detonation pressures and velocities that exceed those of 2,4,6-trinitrotoluene (TNT) and a few have values that approach those of triaminotrinitrobenzene (TATB).

Study of the reactivity of an aggregative explosive sensitized by dynamical damage; Etude de la reactivite d`un explosif agregataire sensibilise par endommagement dynamique

Energy Technology Data Exchange (ETDEWEB)

Pertuis, Ch

1997-11-13

The thermal decomposition of a TATB-based explosive that have been exposed to a projectile impact, is studied in order to determine its sensitivity based on the morphological state of the damaged material. Two self-maintained thermal decomposition modes have been identified, one is a slow mode, the other is a rapid mode; four media have been differentiated in the damaged explosive: sound, porous, micro-cracked and fractured media, and thermal decomposition is studied for each media, using two experimental techniques, manometric bomb and a specifically designed strand burner. Laws giving the regression speed of each media has been established considering confinement pressure and initial temperature of the explosive. Analytical calculations yield the regression speed evolution as a function of certain parameters

Shock initiation experiments on ratchet grown PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Gustavsen, Richard L [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Olinger, Barton W [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Pierce, Timothy H [Los Alamos National Laboratory; Sanchez, Nathaniel J [Los Alamos National Laboratory

2010-01-01

This study compares the shock initiation behavior of PBX 9502 pressed to less than nominal density (nominal density is 1.890 {+-} 0.005 g/cm{sup 3}) with PBX 9502 pressed to nominal density and then ''ratchet grown'' to low density. PBX 9502 is an insensitive plastic bonded explosive consisting of 95 weight % dry-aminated tri-amino-tri-nitro-benzene (TATB) and 5 weight % Kel-F 800 plastic binder. ''Ratchet growth'' - an irreversible increase in specific volume - occurs when an explosive based on TATB is temperature cycled. The design of our study is as follows: PBX 9502, all from the same lot, received the following four treatments. Samples in the first group were pressed to less than nominal density. These were not ratchet grown and used as a baseline. Samples in the second group were pressed to nominal density and then ratchet grown by temperature cycling 30 times between -54 C and +80 C. Samples in the final group were pressed to nominal density and cut into 100 mm by 25.4 mm diameter cylinders. During thermal cycling the cylinders were axially constrained by a 100 psi load. Samples for shock initiation experiments were cut perpendicular (disks) and parallel (slabs) to the axial load. The four sample groups can be summarized with the terms pressed low, ratchet grown/no load, axial load/disks, and axial load/slabs. All samples were shock initiated with nearly identical inputs in plate impact experiments carried out on a gas gun. Wave profiles were measured after propagation through 3, 4, 5, and 6 mm of explosive. Side by side comparison of wave profiles from different samples is used as a measure of relative sensitivity. All reduced density samples were more shock sensitive than nominal density PBX 9502. Differences in shock sensitivity between ratchet grown and pressed to low density PBX 9502 were small, but the low density pressings are slightly more sensitive than the ratchet grown samples.

Unreacted equation of states of typical energetic materials under static compression: A review

International Nuclear Information System (INIS)

Zheng Zhaoyang; Zhao Jijun

2016-01-01

The unreacted equation of state (EOS) of energetic materials is an important thermodynamic relationship to characterize their high pressure behaviors and has practical importance. The previous experimental and theoretical works on the equation of state of several energetic materials including nitromethane, 1,3,5-trinitrohexahydro-1,3,5-triazine (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX), hexanitrostilbene (HNS), hexanitrohexaazaisowurtzitane (HNIW or CL-20), pentaerythritol tetranitrate (PETN), 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), triamino-trinitrobenzene (TATB), 1,1-diamino-2,2-dinitroethene (DADNE or FOX-7), and trinitrotoluene (TNT) are reviewed in this paper. The EOS determined from hydrostatic and non-hydrostatic compressions are discussed and compared. The theoretical results based on ab initio calculations are summarized and compared with the experimental data. (topical review)

Tat proteins as novel thylakoid membrane anchors organize a biosynthetic pathway in chloroplasts and increase product yield 5-fold

DEFF Research Database (Denmark)

Henriques de Jesus, Maria Perestrello Ramos; Nielsen, Agnieszka Janina Zygadlo; Mellor, Silas Busck

2017-01-01

to their complex structures. Some of the crucial enzymes catalyzing their biosynthesis are the cytochromes P450 (P450s) situated in the endoplasmic reticulum (ER), powered by electron transfers from NADPH. Dhurrin is a cyanogenic glucoside and its biosynthesis involves a dynamic metabolon formed by two P450s....... Nevertheless, translocation of the pathway from the ER to the chloroplast creates other difficulties, such as the loss of metabolon formation and intermediate diversion into other metabolic pathways. We show here that co-localization of these enzymes in the thylakoid membrane leads to a significant increase...... in product formation, with a concomitant decrease in off-pathway intermediates. This was achieved by exchanging the membrane anchors of the dhurrin pathway enzymes to components of the Twin-arginine translocation pathway, TatB and TatC, which have self-assembly properties. Consequently, we show 5-fold...

Mechanisms of formation of trace decomposition products in complex high explosive mixtures

Energy Technology Data Exchange (ETDEWEB)

Woodyard, J.D.; Burgess, C.E. [West Texas A and M Univ., Canyon, TX (United States); Rainwater, K.A. [Texas Tech Univ., Lubbock, TX (United States)

1999-03-01

A significant concern in the nation`s stockpile surveillance program in prediction of the lifetimes of the high explosives (HE) and their components as the weapons age. The Department of Energy`s Core Surveillance and Enhanced Surveillance programs specifically target issues of degradation of HE, binders, and plastic-bonded explosives (PBX) for determination of component lifetimes and handling procedures. These material science topics are being addressed at the DOE national laboratories and production plants, including Pantex. The principal goal of this project is to identify the mechanisms of decomposition of HE, plasticizers, plastic polymer binders, and radical stabilizers resulting from exposures to ionizing radiation, heat, and humidity. The following reports the work completed for 1998, including a comprehensive literature review about some of the materials examined and the laboratory work completed to date. The materials focused on in the laboratory are TATB, Estane 5301, and Irganox 1010.

Small scale thermal violence experiments for combined insensitive high explosive and booster materials

Energy Technology Data Exchange (ETDEWEB)

Rae, Philip J [Los Alamos National Laboratory; Bauer, Clare L [AWE, UK; Stennett, C [DCMT SHRIVENHAM, UK; Flower, H M [AWE, UK

2010-01-01

A small scale cook-off experiment has been designed to provide a violence metric for both booster and IHE materials, singly and in combination. The experiment has a simple, axisymmetric geometry provided by a 10 mm internal diameter cylindrical steel confinement up to 80 mm in length. Heating is applied from one end of the sample length creating pseudo 1-D heating profile and a thermal gradient across the sample(s). At the opposite end of the confinement to the heating block, a machined groove provides a point of rupture that generates a cylindrical fragment. The displacement of the external face of the fragment is detected by Heterodyne Velocimetry. Proof of concept experiments are reported focusing on HMX and TATB formulations, and are described in relation to confinement, ullage and heating profile. The development of a violence metric, based upon fragment velocity records is discussed.

Surface energy of explosive nanoparticles

Science.gov (United States)

Pineau, Nicolas; Bidault, Xavier; Soulard, Laurent

2017-06-01

Recent experimental studies show that nanostructuration has a substantial impact on the detonation of high explosives: a nanostructured one leads to smaller nanodiamonds than a microstructured one. Whether it comes from a higher surface energy or from porosity, the origin of these different behaviors must be investigated. The surface energy of TATB nanoparticles with a radius from 2 nm upto 60 nm has been determined by means of ReaxFF-based simulations. Then, using the Rankine-Hugoniot relations and the equation of states of the bulk material, the contribution of this excess energy to the heating of a shock-compressed nanostructured (and porous) material is evaluated and compared to the thermal effect due to its porosity collapse. A maximum temperature increase of 50 K is found for 4-nm nanoparticles, which remains negligible when compared to the few hundred degrees induced by the compaction work.

Thermal chemical-mechanical reactive flow model of shock initiation in solid explosives

International Nuclear Information System (INIS)

Nicholls, A.L. III; Tarver, C.M.

1998-01-01

The three dimensional Arbitrary Lagrange Eulerian hydrodynamic computer code ALE3D with fully coupled thermal-chemical-mechanical material models provides the framework for the development of a physically realistic model of shock initiation and detonation of solid explosives. The processes of hot spot formation during shock compression, subsequent ignition of reaction or failure to react, growth of reaction in individual hot spots, and coalescence of reacting hot spots during the transition to detonation can now be modeled using Arrhenius chemical kinetic rate laws and heat transfer to propagate the reactive flow. This paper discusses the growth rates of reacting hot spots in HMX and TATB and their coalescence during shock to detonation transition. Hot spot deflagration rates are found to be fast enough to consume explosive particles less than 10 mm in diameter during typical shock duration times, but larger particles must fragment and create more reactive surface area in order to be rapidly consumed

The reactants equation of state for the tri-amino-tri-nitro-benzene (TATB) based explosive PBX 9502

Science.gov (United States)

Aslam, Tariq D.

2017-07-01

The response of high explosives (HEs), due to mechanical and/or thermal insults, is of great importance for both safety and performance. A major component of how an HE responds to these stimuli stems from its reactant equation of state (EOS). Here, the tri-amino-tri-nitro-benzene based explosive PBX 9502 is investigated by examining recent experiments. Furthermore, a complete thermal EOS is calibrated based on the functional form devised by Wescott, Stewart, and Davis [J. Appl. Phys. 98, 053514 (2005)]. It is found, by comparing to earlier calibrations, that a variety of thermodynamic data are needed to sufficiently constrain the EOS response over a wide range of thermodynamic state space. Included in the calibration presented here is the specific heat as a function of temperature, isobaric thermal expansion, and shock Hugoniot response. As validation of the resulting model, isothermal compression and isentropic compression are compared with recent experiments.

The equation of state of 5-nitro-2,4-dihydro-1,2,4,-triazol-3-one determined via in-situ optical microscopy and interferometry measurements

Energy Technology Data Exchange (ETDEWEB)

Stavrou, Elissaios, E-mail: stavrou1@llnl.gov; Zaug, Joseph M., E-mail: zaug1@llnl.gov; Bastea, Sorin; Crowhurst, Jonathan C. [Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, P.O. Box 808, Livermore, California 94550 (United States)

2016-04-07

Quasi-hydrostatic high-pressure equations of state (EOS) are typically determined, for crystalline solids, by measuring unit-cell volumes using x-ray diffraction (XRD) techniques. However, when characterizing low-symmetry materials with large unit cells, conventional XRD approaches may become problematic. To overcome this issue, we examined the utility of a “direct” approach toward determining high pressure material volume by measuring surface area and sample thickness using optical microscopy and interferometry (OMI), respectively. We have validated this experimental approach by comparing results obtained for 2,4,6-triamino-1,3,5-trinitrobenzene TATB with an EOS determined from synchrotron XRD measurements; and, a good match is observed. We have measured the high pressure EOS of 5-nitro-2,4-dihydro-1,2,4,-triazol-3-one (α-NTO) up to 28 GPa. No high-pressure XRD EOS data have been published on α-NTO, probably due to its complex crystal structure. The results of this study suggest that OMI is a reliable and versatile alternative for determining EOSs, especially when conventional methodologies are impractical.

Absolute single-ion solvation free energy scale in methanol determined by the lithium cluster-continuum approach.

Science.gov (United States)

Pliego, Josefredo R; Miguel, Elizabeth L M

2013-05-02

Absolute solvation free energy of the lithium cation in methanol was calculated by the cluster-continuum quasichemical theory of solvation. Clusters with up to five methanol molecules were investigated using X3LYP, MP2, and MP4 methods with DZVP, 6-311+G(2df,2p), TZVPP+diff, and QZVPP+diff basis sets and including the cluster solvation through the PCM and SMD continuum models. Our calculations have determined a value of -118.1 kcal mol(-1) for the solvation free energy of the lithium, in close agreement with a value of -116.6 kcal mol(-1) consistent with the TATB assumption. Using data of solvation and transfer free energy of a pair of ions, electrode potentials and pKa, we have obtained the solvation free energy of 25 ions in methanol. Our analysis leads to a value of -253.6 kcal mol(-1) for the solvation free energy of the proton, which can be compared with the value of -263.5 kcal mol(-1) obtained by Kelly et al. using the cluster pair approximation. Considering that this difference is due to the methanol surface potential, we have estimated that it corresponds to -0.429 V.

Thermal decomposition and reaction of confined explosives

International Nuclear Information System (INIS)

Catalano, E.; McGuire, R.; Lee, E.; Wrenn, E.; Ornellas, D.; Walton, J.

1976-01-01

Some new experiments designed to accurately determine the time interval required to produce a reactive event in confined explosives subjected to temperatures which will cause decomposition are described. Geometry and boundary conditions were both well defined so that these experiments on the rapid thermal decomposition of HE are amenable to predictive modelling. Experiments have been carried out on TNT, TATB and on two plastic-bonded HMX-based high explosives, LX-04 and LX-10. When the results of these experiments are plotted as the logarithm of the time to explosion versus 1/T K (Arrhenius plot), the curves produced are remarkably linear. This is in contradiction to the results obtained by an iterative solution of the Laplace equation for a system with a first order rate heat source. Such calculations produce plots which display considerable curvature. The experiments have also shown that the time to explosion is strongly influenced by the void volume in the containment vessel. Results of the experiments with calculations based on the heat flow equations coupled with first-order models of chemical decomposition are compared. The comparisons demonstrate the need for a more realistic reaction model

Double Shock Experiments Performed at -55°C on LX-17 with Reactive Flow Modeling to Understand the Reacted Equation of State

Science.gov (United States)

Dehaven, Martin R.; Vandersall, Kevin S.; Strickland, Shawn L.; Fried, Laurence E.; Tarver, Craig M.

2017-06-01

Experiments were performed at -55°C to measure the reacted state of LX-17 (92.5% TATB and 7.5% Kel-F by weight) using a double shock technique using two flyer materials (with known properties) mounted on a projectile that send an initial shock through the material close to the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. Information on the reacted state is obtained by measuring the relative timing and magnitude of the first and second shock waves. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include a comparison to prior work at ambient temperature, the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Machine Learning Intermolecular Potentials for 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) Using Symmetry-Adapted Perturbation Theory

Science.gov (United States)

2018-04-25

Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that...speech recognition,3 fraud prevention,4 spam email filtering,5 unmanned vehicle operation ,6 finance,7 and even drunk driver detection,8 ML has now...Ridge Regression KRR can be derived from Eq. 2 by ignoring the bias term b, setting ε = 0, and squaring the “ slack variables” ξ. This yields the

Double shock experiments and reactive flow modeling on LX-17 to understand the reacted equation of state

International Nuclear Information System (INIS)

Vandersall, Kevin S; Garcia, Frank; Fried, Laurence E; Tarver, Craig M

2014-01-01

Experimental data from measurements of the reacted state of an energetic material are desired to incorporate reacted states in modeling by computer codes. In a case such as LX-17 (92.5% TATB and 7.5% Kel-F by weight), where the time dependent kinetics of reaction is still not fully understood and the reacted state may evolve over time, this information becomes even more vital. Experiments were performed to measure the reacted state of LX-17 using a double shock method involving the use of two flyer materials (with known properties) mounted on the projectile that send an initial shock through the material close to or above the Chapman-Jouguet (CJ) state followed by a second shock at a higher magnitude into the detonated material. By measuring the parameters of the first and second shock waves, information on the reacted state can be obtained. The LX-17 detonation reaction zone profiles plus the arrival times and amplitudes of reflected shocks in LX-17 detonation reaction products were measured using Photonic Doppler Velocimetry (PDV) probes and an aluminum foil coated LiF window. A discussion of this work will include the experimental parameters, velocimetry profiles, data interpretation, reactive CHEETAH and Ignition and Growth modeling, as well as detail on possible future experiments.

Impact of surface energy on the shock properties of granular explosives

Science.gov (United States)

Bidault, X.; Pineau, N.

2018-01-01

This paper presents the first part of a two-fold molecular dynamics study of the impact of the granularity on the shock properties of high explosives. Recent experimental studies show that the granularity can have a substantial impact on the properties of detonation products {i.e., variations in the size distributions of detonation nanodiamonds [V. Pichot et al., Sci. Rep. 3, 2159 (2013)]}. These variations can have two origins: the surface energy, which is a priori enhanced from micro- to nano-scale, and the porosity induced by the granular structure. In this first report, we study the impact of the surface-energy contribution on the inert shock compression of TATB, TNT, α-RDX, and β-HMX nano-grains (triaminotrinitrobenzene, trinitrotoluene, hexogen and octogen, respectively). We compute the radius-dependent surface energy and combine it with an ab initio-based equation of state in order to obtain the resulting shock properties through the Rankine-Hugoniot relations. We find that the enhancement of the surface energy results in a moderate overheating under shock compression. This contribution is minor with respect to porosity, when compared to a simple macroscopic model. This result motivates further atomistic studies on the impact of nanoporosity networks on the shock properties.

Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

Energy Technology Data Exchange (ETDEWEB)

Souers, P C; Hernandez, A; Cabacungan, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

2008-02-05

Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in 0 reactive flow JWL++ and Linked Cheetah V4, mostly at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. The physical basis of the input parameters is considered.

Modeling Hemispheric Detonation Experiments in 2-Dimensions

Energy Technology Data Exchange (ETDEWEB)

Howard, W M; Fried, L E; Vitello, P A; Druce, R L; Phillips, D; Lee, R; Mudge, S; Roeske, F

2006-06-22

Experiments have been performed with LX-17 (92.5% TATB and 7.5% Kel-F 800 binder) to study scaling of detonation waves using a dimensional scaling in a hemispherical divergent geometry. We model these experiments using an arbitrary Lagrange-Eulerian (ALE3D) hydrodynamics code, with reactive flow models based on the thermo-chemical code, Cheetah. The thermo-chemical code Cheetah provides a pressure-dependent kinetic rate law, along with an equation of state based on exponential-6 fluid potentials for individual detonation product species, calibrated to high pressures ({approx} few Mbars) and high temperatures (20000K). The parameters for these potentials are fit to a wide variety of experimental data, including shock, compression and sound speed data. For the un-reacted high explosive equation of state we use a modified Murnaghan form. We model the detonator (including the flyer plate) and initiation system in detail. The detonator is composed of LX-16, for which we use a program burn model. Steinberg-Guinan models5 are used for the metal components of the detonator. The booster and high explosive are LX-10 and LX-17, respectively. For both the LX-10 and LX-17, we use a pressure dependent rate law, coupled with a chemical equilibrium equation of state based on Cheetah. For LX-17, the kinetic model includes carbon clustering on the nanometer size scale.

Metodologi Hukum Islam ‘Abd al-Halîm Mahmûd

Directory of Open Access Journals (Sweden)

M. Lathoif Ghozali

2015-09-01

Full Text Available This article discusses the concept of ijtihâd (legal reasoning and the typology of legal thought of ‘Abd al-Halîm Mahmûd. According to Mahmûd, ijtihad is devoting all abilities of a mujtahid to arrive at the essence and substance of a problem intended by the Prophet Muhammad. This definition is supported by the division of ijtihâd into two: ijtihâd istinbâtî, the object of which is the texts of the Qur’ân or the Sunnah, and ijtihâd tatbîqî, the object of which is legal problems of the time. Mahmud maintains that a mujtahid should meet certain qualifications such as the abilities of understanding Arabic language, memorizing the Qur’ân, understanding asbâb al-nuzûl (causes of revelation, memorizing the Traditions of the Prophet related to legal matters, and the brilliance in making legal reasoning and conclusions. Mahmûd belongs to moderate group that agrees with the formalization of private laws, while public laws in his view serve only as materials for national laws. Mahmûd also gives an emphasis on the integration between nass (text and maqâsid al-sharî‘ah (the objectives of law.

An integrated theoretical and experimental investigation of insensitive munition compounds adsorption on cellulose, cellulose triacetate, chitin and chitosan surfaces.

Science.gov (United States)

Gurtowski, Luke A; Griggs, Chris S; Gude, Veera G; Shukla, Manoj K

2018-02-01

This manuscript reports results of combined computational chemistry and batch adsorption investigation of insensitive munition compounds, 2,4-dinitroanisole (DNAN), triaminotrinitrobenzene (TATB), 1,1-diamino-2,2-dinitroethene (FOX-7) and nitroguanidine (NQ), and traditional munition compound 2,4,6-trinitrotoluene (TNT) on the surfaces of cellulose, cellulose triacetate, chitin and chitosan biopolymers. Cellulose, cellulose triacetate, chitin and chitosan were modeled as trimeric form of the linear chain of 4 C 1 chair conformation of β-d-glucopyranos, its triacetate form, β-N-acetylglucosamine and D-glucosamine, respectively, in the 1➔4 linkage. Geometries were optimized at the M062X functional level of the density functional theory (DFT) using the 6-31G(d,p) basis set in the gas phase and in the bulk water solution using the conductor-like polarizable continuum model (CPCM) approach. The nature of potential energy surfaces of the optimized geometries were ascertained through the harmonic vibrational frequency analysis. The basis set superposition error (BSSE) corrected interaction energies were obtained using the 6-311G(d,p) basis set at the same theoretical level. The computed BSSE in the gas phase was used to correct interaction energy in the bulk water solution. Computed and experimental results regarding the ability of considered surfaces in adsorbing the insensitive munitions compounds are discussed. Copyright © 2017. Published by Elsevier B.V.

Fiscal 1993 report on results of R and D on manganese nodule mining system. Manganese nodule mining system (Total system - experiment plan part); 1993 nendo mangan danakai saiko system no kenkyu kaihatsu seika hokokusho. 2/5. Mangan dankai saiko system (total system (jikken keikaku) hen)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

Technology is being developed for mining the nodules existing at a depth of 4,000-6,000 m by a fluid dredge method, with the purpose of securing steady supply of non-ferrous metal resources and enhancing oceanic development technologies. To be concrete, comprehensive oceanic experiments will be conducted in the GA-04 sea area, 600 km southeast of Marcus Island, by developing and experimentally preparing a test system for the mining. In the R and D of a total system, activities were carried out in the two areas of (1) experimental operation section for design and manufacture of experimental equipment and comprehensive experimental simulation, and (2) experimental planning operation section for experimental policy, survey and analysis of sea area for experiment, and research on mining system. In (2), examination of the experiment implementation plan was carried out in the case where, as the experimental plan, the first stage experiment is implemented in TA-GA sea area and the second stage experiment in TA-TB sea area with abundant nodules of a submarine mountain in the area; examination was also made on the draft of an experiment implementation guideline suitable for M.S. Hakuryu No.3 as the experimental boat as well as on various guideline plans. In addition, a sensitivity analysis was made on the mining system as the evaluation of cost effectiveness in the case of commercial production. (NEDO)

Determining the Coalescence of Hotspots into Uniform Detonation Fronts in High Explosives

Energy Technology Data Exchange (ETDEWEB)

Steward, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Purdue Univ., West Lafayette, IN (United States); Mays, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Converse, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Baluyot, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tringe, J. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-14

Microwave Interferometry (MI) offers the advantage of a continuous time measurement of detonation front velocity from detonation initiation to disassembly, which is an important step to assure the quality of stockpile high explosives. However, the method is currently characterized by areas of poor signal strength, which lead to low confidence measurements. Experiments in inert materials were conducted to determine if reflective hot spots, pockets of plasma that form during detonation, are responsible due to varying hot spot concentrations. Instead, it was found that the copper tube used in a range of standard HE test configurations is the cause of the poor signal reception. Hot spots were represented by microwave reflective aluminum particles. The aluminum was mixed with Titanium Dioxide, a material electrically similar to the insensitive high explosive, triaminotrinitrobenzene (TATB), in volume percent fractions (VPFs) between 0 and 100% aluminum, in increments of 10%. Reflectivity was measured based on input and reflection received from a test apparatus with a layer representing undetonated explosive and another representing an approaching shockwave. The results showed no correlation between VPF and measured reflectivity test cases while enclosed in the standard copper tube. Upon further testing, each sample’s measured reflectivity independent of the copper enclosure did correlate with VPF. This revealed that the test enclosure currently used for MI measurements is causing poor MI signal reception, and new methods must be developed to account for this aberration in MI measurements.

Dead Zones in LX-17 and PBX 9502

Energy Technology Data Exchange (ETDEWEB)

Souers, P C; Andreski, H G; Batteux, J; Bratton, B; Cabacungan, C; Cook, III, C F; Fletcher, S; Garza, R; Grimsley, D; Handly, J; Hernandez, A; McMaster, P; Molitoris, J D; Palmer, R; Prindiville, J; Rodriguez, J; Schneberk, D; Wong, B; Vitello, P

2005-09-06

Pin and X-ray corner-turning data have been taken on ambient LX-17 and PBX 9052, and the results are listed in tables as an aid to future modeling. The results have been modeled at 4 zones/mm with a reactive flow approach that varies the burn rate as a function of pressure. A single rate format is used to simulate failure and detonation in different pressure regimes. A pressure cut-off must also be reached to initiate the burn. Corner-turning and failure are modeled using an intermediate pressure rate region, and detonation occurs at high pressure. The TATB booster is also modeled using reactive flow, and X-ray tomography is used to partition the ram-pressed hemisphere into five different density regions. The model reasonably fits the bare corner-turning experiment but predicts a smaller dead zone with steel confinement, in contradiction with experiment. The same model also calculates the confined and unconfined cylinder detonation velocities and predicts the failure of the unconfined cylinder at 3.75 mm radius. The PBX 9502 shows a smaller dead zone than LX-17. An old experiment that showed a large apparent dead zone in Comp B was repeated with X-ray transmission and no dead zone was seen. This confirms the idea that a variable burn rate is the key to modeling. The model also produces initiation delays, which are shorter than those found in time-to-detonation.

Development of a reactive burn model based upon an explicit visco-plastic pore collapse model

Science.gov (United States)

Bouton, Eric; Lefrançois, Alexandre; Belmas, Robert

2015-06-01

Our aim in this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the initiation and shock to detonation of pressed TATB explosives. For the sake of simplicity, the hot spots are supposed to result from the viscoplastic collapse of spherical micro-voids inside the composition. Such a model has been incorporated in a lagrangian hydrodynamic code. In our calculations, 8 different pore diameters, ranging from 100 nm to 1.2 μm, have been taken into account and the porosity associated to each pore size has been deduced from the PBX-9502 void distribution derived from the SAXS. The last ingredient of our model is the burn rate that depends on two main variables. The first one is the shock pressure as proposed by the developers of the CREST model. The second one is the number of effective chemical reaction sites calculated by the microscopic model. Furthermore, the function of the reaction progress variable of the burn rate is similar to that in the SURF model proposed by Menikoff. Our burn rate has been calibrated by using pressure profile, material velocities wave forms obtained with embedded particle velocity gauges and run distance to detonation. The comparison between the numerical and experimental results is really good and sufficient to perform a wide variety of simulations including single, double shock waves and the desensitization phenomenon. In conclusion, future works are described.

Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

Energy Technology Data Exchange (ETDEWEB)

Souers, P C; Hernandez, A; Cabacungen, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

2007-05-30

Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in the Linked Cheetah V4.0 reactive flow code at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. A report card of 25 tests run with the same settings on LX-17 is shown, possibly the most extensive simultaneous calibration yet tried with an explosive. The physical basis of some of the input parameters is considered.

Improved Reactive Flow Modeling of the LX-17 Double Shock Experiments

Science.gov (United States)

Rehagen, Thomas J.; Vitello, Peter

2017-06-01

Over driven double shock experiments provide a measurement of the properties of the reaction product states of the insensitive high explosive LX-17 (92.5% TATB and 7.5% Kel-F by weight). These experiments used two flyer materials mounted on the end of a projectile to send an initial shock through the LX-17, followed by a second shock of a higher magnitude into the detonation products. In the experiments, the explosive was initially driven by the flyer plate to pressures above the Chapman-Jouguet state. The particle velocity history was recorded by Photonic Doppler Velocimetry (PDV) probes pointing at an aluminum foil coated LiF window. The PDV data shows a sharp initial shock and decay, followed by a rounded second shock. Here, the experimental results are compared to 2D and 3D Cheetah reactive flow modeling. Our default Cheetah reactive flow model fails to accurately reproduce the decay of the first shock or the curvature or strength of the second shock. A new model is proposed in which the carbon condensate produced in the reaction zone is controlled by a kinetic rate. This allows the carbon condensate to be initially out of chemical equilibrium with the product gas. This new model reproduces the initial detonation peak and decay, and matches the curvature of the second shock, however, it still over-predicts the strength of the second shock. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Shock Initiation of Damaged Explosives

Energy Technology Data Exchange (ETDEWEB)

Chidester, S K; Vandersall, K S; Tarver, C M

2009-10-22

Explosive and propellant charges are subjected to various mechanical and thermal insults that can increase their sensitivity over the course of their lifetimes. To quantify this effect, shock initiation experiments were performed on mechanically and thermally damaged LX-04 (85% HMX, 15% Viton by weight) and PBX 9502 (95% TATB, 5% Kel-F by weight) to obtain in-situ manganin pressure gauge data and run distances to detonation at various shock pressures. We report the behavior of the HMX-based explosive LX-04 that was damaged mechanically by applying a compressive load of 600 psi for 20,000 cycles, thus creating many small narrow cracks, or by cutting wedge shaped parts that were then loosely reassembled, thus creating a few large cracks. The thermally damaged LX-04 charges were heated to 190 C for long enough for the beta to delta solid - solid phase transition to occur, and then cooled to ambient temperature. Mechanically damaged LX-04 exhibited only slightly increased shock sensitivity, while thermally damaged LX-04 was much more shock sensitive. Similarly, the insensitive explosive PBX 9502 was mechanically damaged using the same two techniques. Since PBX 9502 does not undergo a solid - solid phase transition but does undergo irreversible or 'rachet' growth when thermally cycled, thermal damage to PBX 9502 was induced by this procedure. As for LX-04, the thermally damaged PBX 9502 demonstrated a greater shock sensitivity than mechanically damaged PBX 9502. The Ignition and Growth reactive flow model calculated the increased sensitivities by igniting more damaged LX-04 and PBX 9502 near the shock front based on the measured densities (porosities) of the damaged charges.

Recent advances in thermal analysis and stability evaluation of insensitive plastic bonded explosives (PBXs)

International Nuclear Information System (INIS)

Yan, Qi-Long; Zeman, Svatopluk; Elbeih, Ahmed

2012-01-01

Highlights: ► We summarize currently used insensitive polymer based explosives and their ingredients. ► We examine the calculation methods that are suitable for kinetic evaluation of polymer based explosives. ► The calculation method for thermal stability parameters of polymer based explosives are summarized, which mainly include shelf life, explosion delay, critical temperature, thermostability threshold, 500 day cookoff temperature and approximate time to explosion. ► The polymer bases could greatly affect the thermal properties of PBXs, including their thermal stability, kinetic parameters and thermodynamic properties. ► PBXs, containing some innovative energetic fillers such as CL-20, NTO, Fox-12 and BCHMX, are only at design stage, which need more research work in the future. - Abstract: In this paper, several fundamental investigations published over the past decades with regard to the thermal analysis of polymer-based explosives (PBXs) have been briefly reviewed. A number of explosive fillers and polymer bases that were used as their main ingredients of PBXs are summarized herein. In addition, the calculation methods for their decomposition kinetics and thermal stability parameters are also introduced in detail. It was concluded that only PBXs based on HMX, RDX and TATB have been widely investigated, and that some other PBXs containing innovative fillers, such as CL-20, TNAZ, NTO and BCHMX are at the design stage. The isoconversional methods and model fitting procedures are usually used to analyze the discrete thermolysis processes of PBXs. In addition, their thermal stability parameters such as shelf life, explosion delay, critical temperature, thermostability threshold, 500-day cookoff temperature and approximate time to explosion could be calculated easily from the kinetic data.

Recent advances in the molten salt technology for the destruction of energetic materials

International Nuclear Information System (INIS)

Upadhye, R.S.; Watkins, B.E.; Pruneda, C.O.

1995-11-01

The DOE has thousands of pounds of energetic materials which result from dismantlement operations at the Pantex Plant. The authors have demonstrated the Molten Salt Destruction (MSD) Process for the treatment of explosives and explosive-containing wastes on a 1.5 kilogram of explosive per hour scale and are currently building a 5 kilogram per hour unit. MSD converts the organic constituents of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. Any inorganic constituents of the waste, such as binders and metallic particles, are retained in the molten salt. The destruction of energetic material waste is accomplished by introducing it, together with air, into a crucible containing a molten salt, in this case a eutectic mixture of Na, K, and Li carbonates. The following pure component DOE and DoD explosives have been destroyed in LLNL's experimental unit at their High Explosives Applications Facility (HEAF): ammonium picrate, HMX, K-6, NQ, NTO, PETN, RDX, TATB, and TNT. In addition, the following formulations were also destroyed: Comp B, LX-10, LX-16, LX-17, PBX-9404, and XM46, a US Army liquid gun propellant. In this 1.5 kg/hr unit, the fractions of carbon converted to CO and of chemically bound nitrogen converted to NOx were found to be well below 1T. In addition to destroying explosive powders and molding powders the authors have also destroyed materials that are typical of real world wastes. These include shavings from machined pressed parts of plastic bonded explosives and sump waste containing both explosives and non-explosive debris. Based on the information obtained on the smaller unit, the authors have constructed a 5 kg/hr MSD unit, incorporating LLNL's advanced chimney design. This unit is currently under shakedown tests and evaluation

Radiological classification of mandibular fractures

International Nuclear Information System (INIS)

Mihailova, H.

2009-01-01

Mandibular fractures present the biggest part (up to 97%) of the facial bone fractures. Method of choice for diagnosing of mandibular fractures is conventional radiography. The aim of the issue is to present an unified radiological classification of mandibular fractures for the clinical practice. This classification includes only those clinical symptoms of mandibular fracture which could be radiologically objectified: exact anatomical localization (F1-F6), teeth in fracture line (Ta,Tb), grade of dislocation (D I, D II), occlusal disturbances (O(+), O(-)). Radiological symptoms expressed by letter and number symbols are systematized in a formula - FTDO of mandibular fractures similar to TNM formula for tumours. FTDO formula expresses radiological diagnose of each mandibular fracture but it doesn't include neither the site (left or right) of the fracture, nor the kind and number of fractures. In order to express topography and number of fractures the radiological formula is transformed into a decimal fraction. The symbols (FTD) of right mandible fracture are written in the numerator and those of the left site - in the denominator. For double and multiple fractures between the symbols for each fracture we put '+'. Symbols for occlusal disturbances are put down opposite, the fractional line. So topographo-anatomical formula (FTD/FTD)xO is formed. In this way the whole radiological information for unilateral, bilateral, single or multiple fractures of the mandible is expressed. The information in the radiological topography anatomic formula, resp. from the unified topography-anatomic classification ensures a quick and exact X-ray diagnose of mandibular fracture. In this way contributes to get better, make easier and faster X-ray diagnostic process concerning mandibular fractures. And all these is a precondition for prevention of retardation of the diagnosis mandibular fracture. (author)

Summary of Booster Development and Qualification Report

Energy Technology Data Exchange (ETDEWEB)

Francois, Elizabeth G. [Los Alamos National Laboratory; Harry, Herbert H. [Los Alamos National Laboratory; Hartline, Ernest L. [Los Alamos National Laboratory; Hooks, Daniel E. [Los Alamos National Laboratory; Johnson, Carl E. [Los Alamos National Laboratory; Morris, John S. [Los Alamos National Laboratory; Novak, Alan M. [Los Alamos National Laboratory; Ramos, Kyle J. [Los Alamos National Laboratory; Sanders, Victor E. [Los Alamos National Laboratory; Scovel, Christina A. [Los Alamos National Laboratory; Lorenz, Thomas [LLNL; Wright, Mark [AWE; Botcher, Tod [PANTEX; Marx, Erin [NSWC-IHDIV; Gibson, Kevin [NSWC-IHDIV

2012-06-21

This report outlines booster development work done at Los Alamos National Laboratory from 2007 to present. The booster is a critical link in the initiation train of explosive assemblies, from complex devices like nuclear weapons to conventional munitions. The booster bridges the gap from a small, relatively sensitive detonator to an insensitive, but massive, main charge. The movement throughout the explosives development community is to use more and more insensitive explosive components. With that, more energy is needed out of the booster. It has to initiate reliably, promptly, powerfully and safely. This report is divided into four sections. The first provides a summary of a collaborative effort between LANL, LLNL, and AWE to identify candidate materials and uniformly develop a testing plan for new boosters. Important parameters and the tests required to measure them were defined. The nature of the collaboration and the specific goals of the participating partners has changed over time, but the booster development plan stands on its own merit as a complete description of the test protocol necessary to compare and qualify booster materials, and is discussed in its entirety in this report. The second section describes a project, which began in 2009 with the Department of Defense to develop replacement booster formulations for PBXN-7. Replacement of PBXN-7 was necessary because it contained Triaminotrinitrobenzene (TATB), which was becoming unavailable to the DoD and because it contained Cyclotrimethylenetrinitramine (RDX), which was sensitive and toxic. A LANL-developed explosive, Diaminoazoxyfurazan (DAAF), was an important candidate. This project required any replacement formulation be a drop-in replacement in existing munitions. This project was timely, in that it made use of the collaborative booster development project, and had the additional constraint of matching shock sensitivity. Additionally it needed to be a safety improvement, and a performance