bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerated Aging of a Composite Explosive
Authors: Perrault G. , Béadard M. , Lavertu R. R. , Tremblay M. 
Published: December 2004

AbstractA given formulation of a composite explosive was submitted to accelerated aging at 293 K, 333 K and 353 K for slightly over a year. Extensive determination of mechanical properties were conducted using an Instron Tester to characterize the aging process of the explosive as a whole. The change of elongation at maximum load can be fitted to a third‐order reaction rate giving an enthalpy of activation (Δ Ha) for the aging process of (78 ± 5) kJ/mol. Although the change of stress at maximum load was a function of temperature, it could not be predicted by a simple correlation. Swelling, inverse gas chromatography and N2O evolution by infrared were applied to the samples aged at 333 K. Swelling measurements show a regular increase with aging of the relative number of cross‐linking. Inverse gas chromatography at 373 K in helium indicated a first‐order kinetic aging process for every sample, but the rate constant (k) of the samples aged for 0, 30 and 60 days was slightly lower than the one for samples aged for 130, 250 and 375 days. The N2O evolution measured at 338.5 K in vacuum by infrared absorption indicates an aging process consisting of two consecutive first‐order reactions, the second one being ten times slower than the first one. The first stage, which was also studied by inverse gas chromatography, gives rate constants which are about half as large as those measured by chromatography and confirms the changes in behavior from the samples aged for 0, 30 and 60 days to the samples aged for 130, 250 and 375 days. These results are discussed in relation to an aging process by oxidative cross‐linking of the binder and degradation of the solid explosive.
Form Function for Propellants in Closed Vessel Work
Authors: Vittal D. , Singh S. 
Published: December 2004

AbstractA general theoretical cubic form function for use in closed vessel work during the evaluation of absolute ballistic parameters of propellants is introduced along with the expressions for the coefficients for a number of common propellant shapes. The conditions under which this form function is accurately applicable are also indicated. This form function is superior and gives much more accurate results than the quadratic form function which is in wide use at present. The differences of the cubic form function from the quadratic are also explained.
New adducts of 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX)
Authors: Selig W. 
Published: December 2004

AbstractRelatively stable equimolar adducts of 1,3,5‐trinitro‐1,3,5‐triazacyclohexane were prepared with 2,6‐lutidine‐N‐oxide, 4‐hydroxy‐1‐butanesulfonic acid δ‐sultone (1,4‐butane sultone), and 2,2,6,6‐tetramethyl‐4‐piperidone‐1‐oxyl. Only the last adduct is selective for RDX; the others also form adducts with 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazacyclooctane. A very labile RDX adduct is formed with tetrahydrothiophene‐1‐oxide. Some properties of the new adducts are presented.
Experimental study on the performance of pyrotechnic igniters
Authors: Klingenberg G. 
Published: December 2004

AbstractA special igniter case designed by Dynamit Nobel AG was used for measuring the energy output of four different igniter formulations in terms of gas pressure, flame temperature, and gas velocity in order to study the performance of pyrotechnic igniter systems, and to evaluate the energy flux at the igniter vent. Four igniter systems were defined which consisted of (a) B‐KNO3, (b) black powder, (c) nitrocellulose, and (d) mixtures of nitrocellulose with black powder. Firings into open air, propellant dummy loads, and propellant beds were carried out with these igniters to obtain their general characteristics. It has been found that the vent characteristics of these pyrotechnic igniters are determined by the confinement conditions used. The energy flux at the igniters vent increased considerably for firings into inert or active propellant beds.
Use of NMR spectrometry for studying the acetolysis of hexamethylenetetramine III. The reaction between hexamethylenetetramine and acetic anhydride to form TRAT
Authors: Shaofang Wang , Ju Chen , Fuping Li 
Published: December 2004

AbstractThe acetolysis of hexamethylenetetramine (HA) to form 1,3,5‐triacetyl‐1,3,5‐triazacyclohexane (TRAT) has studied by NMR. It was found that this reaction experienced two different courses. HA turned to TRAT through the intermediate 3,7‐diacetyl‐1,3,5,7‐tetraaza‐[3.3.1]‐bicyclononace (DAPT), and HA converted at first to an intermediate M1, which gave TRAT through another intermediate M2 in the presence of water. Based on the 1H and 13C spectra, the change in the spectra with reaction and the possibility of reaction, we assumed both the structure of M2 and its reaction mechanism.
The Rheological Properties of Plasticized Nitrocellulose as a function of nitrocellulose precursor
Authors: Baker F. S. , Healey M. J. , Privett G. 
Published: December 2004

AbstractPropellant cords have been manufactured from nitrocellulose/nitroglycerin (50/50) pastes containing different types of nitrocellulose. The cords were manufactured using a solvent wet process involving incorporation and extrusion in the highly instrumented propellants processing facility at Waltham Abbey. It has been shown that the biological source from which the nitrocellulose is manufactured (wood or cotton) has a significant influence upon the dough rheology, cord diameter, shear heating and ultimate tensile strength of the dried cords. Additionally, the influence of extrusion rate upon the above parameters has been highlighted. This work compliments that previously undertaken upon the influence of nitrocellulose molecular weight on the properties of propellant doughs and dried cords.
Detonation sensitivity of liquid nitromethane doped with methyl nitrite
Authors: Engelke R. , Earl W. L. , Storm C. B. 
Published: December 2004

AbstractIt has been suggested, by other workers, that the isomerization of normal nitromethane (NMCH3NO2) to methyl nitrite (CH3ONO) is an important first step in the chemical kinetics of liquid NM detonation. We examine this idea by studying the effect of direct methyl nitrite addition on NM's detonation sensitivity. Failure diameter is used as the measure of sensitivity. A comparison is made between the effect of methyl nitrite addition and that of a known sensitizer of NM i.e., the NM aci ion (CH2NO2−). Methyl nitrite is found to be an ineffective sensitizer relative to NM's aci ion.
Effect of Moving Plate on Jet‐Penetration
Authors: Yadav H. S. , Kamat P. V. 
Published: December 2004

AbstractEffect of a moving plate between a shaped charge jet and the target on jet‐penetration has been investigated theoretically. It has been assumed that the plate moves undeformed with uniform velocity, and jet‐penetration in the plate or the target occurs hydrodynamically so that the impact of the jet produces a hole in the plate whose diameter is bigger than that of the jet. The free passage of the jet through this hole is intercepted when the jet touches the wall of the hole due to its transverse motion. The presence of a moving plate between the jet and the target has been found many times more effective than that of a stationary plate in reducing the jet penetration in the target. The effect of angle of attack, velocity of the plate and initial distance between the plate and the target on penetration, produced by the jet going out of the plate, has been investigated for a typical set of arbitrarily selected values of jet and plate parameters.
The Density Distribution in Pressed Charges. An analytical approach
Authors: Saßmannshausen U. , Essig W. , Osswald T. A. 
Published: December 2004

AbstractHigh performance shaped charges require a perfect rotational symmetry and homogenity in structure. Therefore the density distribution of the explosive inside the charge has to meet the same specifications in order to obtain the desired geometry of the detonation wave. In this paper we present an analytical model which describes the density inside the charge as a function of the pressure and the friction between the tool surface and the granulate. The density distribution inside a cylindrical body has been calculated. The comparison with experimental data shows a good agreement.
Analysis of the initial stages of the Thermal Decomposition of 1,4‐Butanediammonium Dinitrate
Authors: Quirke J. M. E. , Fu J. , Hardy K. A. , Sheldon J. W. , Doolittle F. G. , McKenney R. L. 
Published: December 2004

AbstractThe initial stages of the decomposition of 1,4‐butanediammonium dinitrate (BDD) were investigated using a molecular beam sampling time‐of‐flight‐quadrupole mass spectrometer system. Experimental results are consistent with the hypothesis that the compound undergoes dissociation into 1,4‐butanediamine and nitric acid. Standard electron impact ionisation and fast atom bombardment mass spectrometric analyses of BDD gave support to the molecular beam study.
Deuterium Isotope Effects during HMX Combustion: Chemical kinetic burn rate control mechanism verified
Authors: Shackelford S. A. , Goshgarian B. B. , Chapman R. D. , Askins R. E. , Flanigan D. A. , Rogers R. N. 
Published: December 2004

AbstractThe appearance of a significant deuterium isotope effect during the combustion of the solid HMX compound verifies that the chemical reaction kinetics is a major contributor in determining the experimentally observed or global burn rate. Burn rate comparison of HMX and its deuterium labeled HMX‐d8 analogue reveals a primary kinetic deuterium isotope effect (1° KDIE) at 500 psig (3.55 MPa) and l000 psig (6.99 MPa) pressures and selectively identifies covalent carbon‐hydrogen bond rupture as the mechanistic step which ultimately controls the HMX bum rate under the static combustion conditions of this experiment. The 1° KDIE value further suggests the rate‐limiting CH bond rupture occurs during the solid state HMX decomposition/deflagration portion of the overall combustion event and is supported by other independently published studies. A possible anomalous KDIE result at 1500 psig (10.4 MPa) is addressed. This condensed phase KDIE approach illustrates a direct link between lower temperature/pressure thermal decomposition and deflagration processes and their potential applicability to the combustion regime. Most importantly, a new general method is demonstrated for mechanistic combustion investigations which selectively permits an in‐situ identification of the compound's burn rate‐controlling step.
Synthesis of Polynitrocompounds from Nitroguanidine
Authors: Yongzhong Yu , Zhuang Su , Baoru Duan , Fubo Chen 
Published: December 2004

AbstractThe reactions of nitroguanidine (NG) with urotropine or formaldehyde have been studied. The following compounds are synthesized from NG:

6‐nitroimino‐1,3,5‐trinitro‐1,3,5‐triazacyclohexane [2] and a number of itsderivatives;
bis(nitroguanidino)methane [9], a valuable intermediate for preparing some high explosives;
1,5‐dinitro‐2,4‐dinitroimino‐1,3,5triazacyclohexane [10] and some of its derivatives via intramolecular cyclization of [9];
2‐nitroimino‐1,3‐diaza‐5‐oxacyclohexane [15], 1‐(nitroguanidinomethyl)‐2‐nitroimino‐1,3‐diaza‐5‐oxacyclohexyl [14], and bis(2‐nitroimino‐1,3‐diaza‐5‐oxacyclohexyl)methane [16] by reactions of [9] with formaldehyde.
Some detonation data of the above compounds are reported. Campounds [2] and [10] are powerful explosives but very unstable thermally and easily hydrolized. However, compounds [14], [15], and [16] possess a better stability than triazacyclic polynitrocompounds containing nitroimino groups, such as [2] and [10].
Condensed phase reaction of boron with potassium nitrate
Authors: Yano Yutaka 
Published: December 2004

AbstractThe reaction process of boron (B) and potassium nitrate (PN) was examined with a thermochemical analysis. The process consists of a three‐stage gasification reaction. A significant heat is produced in the first‐stage process which is caused by the reaction B + KNO3 → KBO2 + NO. In the second‐stage process, the remaining unreacted PN decomposes to produce gaseous oxidizing fragments. The KBO2 produced in the first‐stage process decomposes in the third‐stage process. Thc heat produced in the first‐stage process is correlated with the mass fraction of B mixed within the B/PN mixture.
Rheology of Emulsion Explosives: a Practical Method
Authors: Cartwright R. V. 
Published: December 2004

AbstractThe Laray viscometer has been found to be useful for rheological characterization of the type of invert emulsion currently being utilized in commercial explosives. Shear rate can be varied over a range which encompasses typical emulsion processing conditions. The viscometer is also relatively inexpensive and simple to operate. Emulsion rheology is distinctly non‐Kewtonian. Dependence of shear stress on shear rate is in accord with the power law, with shear rate exponents (n) varying from 0.3 to 0.6. Both n and the pre‐exponential factor τref depend on emulsion composition and processing history in a manner consistent with known emulsion rheology.
Study of the explosive behavior of highly confined cast PBXs submitted to bullet impact
Authors: Kent R. , Pinchot J. L. 
Published: December 2004

AbstractSince many years, SNPE is trying to get a better understanding of the mechanisms which govern the bullet impact reactivity of highly confined eastable plastic bonded high explosives. In a first part, the different research thrust lines and the principal results are presented. In a second part are presented some results of bullet impact tests performed with instrumented small scale warheads which can be open after test without hazard. These small scale warheads are filled with disks of explosive and inert material. The presence of this inert material, which has the same mechanical properties that the explosive, allows to reduce the level of reaction and then, it is possible to:

measure the stresses induced by the impact,
localize the ignition points,
assess the amount of damage,
determine the amount of explosive having recated.
Combustion of Black Powder. Part III: Hot stage microscopy studies
Authors: Hussain G. , Rees G. J. 
Published: December 2004

AbstractA hot‐stage unit, operating over the temperature range from ambient to 1000°C has been used to study the combustion of black powder. Direct observation of heating of mixtures was supplemented by 35‐mm photomicrography. Results are presented for black powder supplied and mixture prepared in the laboratory.
Modeling Hydrodynamic Behaviors in Detonation
Authors: Tang P. K. 
Published: December 2004

AbstractA multistage reaction model developed for general use from initiation through detonation of heterogeneous high explosives is used to specifically simulate the interface vclocimetry and plate push experiments of a triamino‐trinitrobenzene‐based explosive in detonation. A simplification of the unified model leads to a rate relation that ineludes only two dominant stages: a fast one that represents the major portion of reaction dictated by propagation and decomposition, and a slow one that reflects probably the formation of large carbon molecules. The apparent more energetic behavior of the equation of state near the detonation front is actually due to the slow reaction process.
Analysis of a shaped charge jet with the double‐orthogonal‐synchro‐streak technique
Authors: Held Manfred 
Published: December 2004

AbstractRecording the trajectory of a fully‐particulated shaped charge jet at two different positions along its flight path, in two mutually orthogonal planes at each recording station, allows the decomposition of the overall transverse velocities of the particles into two components. This can be done by analysing the differences in the deviations observed at the two stations. The overall transverse velocities are composed of the vector sums of those lateral‐ or off‐axis velocities which are intrinsic to the collapse process, and additional increments that are superimposed later as a result of particulation itself. In this paper the “IEPG Shaped Charge” has been used as an example to demonstrate the Double‐OSST measurement technique.In these experiments, the overall transverse velocities derived are clearly larger than those seen between the collapse line and the first observation station. On the “Z” diagram (dispersion to the charge axis), the measurements made on this shaped charge do not exhibit random radial dispersion in all direction, but rather the particles spread out into a fan which expands more or less within one quadrant.
Electrolytic coloration of lithium‐doped strontium fluoride crystals
Authors: Song Cuiying , Gu Hongen , Han Li , Wu Yanru 
Published: December 2004

AbstractLithium‐doped strontium fluoride crystals were successfully colored electrolytically, and a lot of F, M (F2), M+ (F2+) and unidentified color centers were effectively produced in the colored crystals, which should mainly benefit from the appropriate impurity doped in the crystals, coloration temperature and electric field strength.
Growth of In2O3 thin films on silicon by the metalorganic chemical vapor deposition method
Authors: Kim Nam Ho , Myung Ju Hyun , Kim Hyoun Woo , Lee Chongmu 
Published: December 2004

AbstractWe have deposited indium oxide (In2O3) films on silicon substrates by the metal organic chemical vapor deposition (MOCVD). We have investigated the effect of substrate temperature on growth and structural properties of films in the range of 200–300 °C. The films had a preferred orientation along [111] direction, with the X‐ray diffraction (XRD) full width at half‐maximum (FWHM) of less than 0.4°.
The fluorination of the surface of elemental carbon. II—Deposition and stability of florine‐containing species: X‐ray photoelectron spectroscopic studies of flourinated graphite
Authors: Cadman P. , Scott J. D. , Thomas J. M. 
Published: December 2004

AbstractX‐ray photoelectron spectroscopy (XPS) has been used to investigate the interaction of fluorine‐containing intermediates with the basal plane of freshly cleaved graphite. A polymeric film of polytetrafluoroethylene (PTFE) on the carbon surface was formed on the basal plane by the interaction of microwave discharged hexafluoroethane and tetrafluoroethylene at 0.1 Torr pressure. Photolysis of tetrafluoroethylene near the graphite deposited submonolayer quantities of PTFE on the basal surface. Similar photolysis of hexafluoroacetone produced a reaction of trifluoromethyl radicals with carbon atoms in the graphite surface.
Quantitative secondary ion mass spectrometry: A review
Authors: Werner H. W. 
Published: December 2004

AbstractQuantitative analysis in general aims at determining the value of a selected physical or chemical property of a given sample. With SIMS, in particular, the parameters to be determined are the concentration of a given element and also its distribution, both in depth and along the surface. Every measurement is affected by a given overall uncertainty due to statistical fluctuations in the measured signal and to systematic errors related to the experimental conditions. A discussion is devoted to the experimental conditions which influence the reproducibility of the measured signal and give rise to systematic errors, e.g. charging effects, matrix effects, selective sputtering and mass‐dependent transmission, etc. The various methods used to derive the desired elemental concentration and its distribution in the sample from the raw measured data are evaluated, namely the use of calibration curves, relative sensitivity factors, fitting parameter methods and first‐principle methods. Finally, the question is considered of how representative is the value determined from the (usually small) volume with respect to the composition of the bulk of the sample (sampling error).
Low energy nitrogen implantation profiles in cobalt using AES
Authors: Malherbe J. B. , Hofmann S. 
Published: December 2004

AbstractUsing AES in combination with argon depth profiling, low energy (0.5–5 keV) nitrogen implantation profiles were determined. The profiles show reasonable agreement to the Schulz‐Wittmaack model of ion collection during sputtering when the effect of the finite escape depth of the Auger electrons is taken into account. The projected ranges of nitrogen in cobalt obtained when using this model shows reasonable correspondence with the LSS‐calculated ones.
Chemical and structural characterization of epitaxial compound semiconductor layers using X‐ray photoelectron diffraction
Authors: Evans Stephen , Scott Michael D. 
Published: December 2004

AbstractThe application of angle‐resolved X‐ray photoelectron spectroscopy (X‐ray photoelectron diffraction) to characterize thin layers of compound semiconductors grown on single crystal substrates is described. In studies of ZnSe grown on (100) GaAs, confirmation of the epitaxial character of the growth, together with a quantitative estimate (±5%) of the stoichiometry of the ZnSe layer, were achieved by means of a single experiment. The techniques described are equally applicable to very thin layers (<10nm) which cannot easily be characterized by established methods.
The inelastic mean free paths of auger electrons in thin films of copper and nickel
Authors: Burke M. A. , Schreurs J. J. 
Published: December 2004

AbstractThe inelastic mean free paths of 600–1000 eV Auger electrons have been determined in Cu and Ni films. Thin films of known thickness were produced by the vapor deposition of Cu on Ni substrates and vice versa. The strengths of the characteristic Auger signals of Cu and Ni were monitored as a function of film thickness. Values of the mean free paths are presented and compared to values previously published by other workers. By monitoring the strengths of the Auger signals from the condensate, it is concluded that backscattering factors for a Ni substrate carrying a Cu film are higher than the backscattering factors for a Cu substrate carrying a Ni film.
Analysis of polymer surfaces by SIMS. 2—fingerprint spectra from simple polymer films
Authors: Briggs D. 
Published: December 2004

AbstractSeven polymers (low density polyethylene, polypropylene, polystyrene, polymethylmethacrylate, poly(methacrylic acid), Nylon‐6 and poly(ethyleneterephthalate)) have been studied by SIMS. Very good signal: noise spectra up to mass 250 have been obtained using low damage conditions (i.e. ion current densities ∽1 nA cm−2) and electron beam charge neutralization. The spectra are highly characteristic and fairly easily interpreted using fragmentation data from electron impact mass spectrometry.
Determination of metallic impurities in a‐Si:H by SIMS
Authors: Scilla G. J. , Ceasar G. P. 
Published: December 2004

AbstractSecondary ion mass spectrometry (SIMS) has been employed to characterize the metallic impurities introduced into ion beam deposited a‐Si: H. For quantitative results, this type of characterization normally requires a specific standard for each element of interest. Ion implantation has been the method of choice for providing these types of standards in Si. The problem with this approach is the time and cost required in obtaining implants for each element to be analyzed. In this study, we describe the application of the local thermal equilibrium (LTE) model of SIMS quantitation to the analysis of metallic impurities in an a‐Si: H matrix. This method circumvents the need for specific standards for each element. Our results indicate that useful quantitative data can be obtained using the LTE method calibrated with one boron implant into c‐Si wafer.