bluuebunny/crossref_metadata_2025_split huggingface dataset:
Esters nitriques de polyols. Conformation de la nitroglycérine. Résonance magnétique nucléaire et moment dipolaire
Authors: Lemanceau B. , Caire‐Maurisier M. 
Published: May 2005

AbstractLe spectre RMN de la nitroglycérine, du type ABCA'B', montre que la molécule est symétrique par rapport au plan HCO passant par le carbone central. Les constantes de couplage protonique peuvent être interprétées par la rigidié du squelette CH2CHCH2 qui se présente alors sous deux conformations possibles telles que deux motifs magnified image contigus soient en position presque éclipsée. Il en est de même pour les groupes CH2ONO2, CHONO2 du dinitrate de propane diol 1–2 et trinitrate de butane triol 1–2–4. Un calcul du moment dipolaire de la nitroglycérine en fonction de la conformation du squelette CH2CHCH2 et de la rotation des groupes NO3 autour des liaisons CO, montre que ce dernier facteur a autant d'importance que le premier. Il ne nous semble donc pas nécessaire de supposer une modification du squelette pour expliquer les variations du moment dipolaire de la nitroglycérine en fonction du solvant.
Brittle Tensile Failure Characteristics of Propellants derived from flexural tests
Authors: Margetson J. , Brokenbrow B. E. 
Published: May 2005

AbstractThe low temperature failure characteristics of two types of solid propellant are derived from the flexural tests on round bar specimens. Quantities which measure strength and variability are established and master curves expressing these quantities in terms of strain rate and temperature are determined. The method is applied to two types of propellants and failure probability contour curves are obtained for each material.
Growth of 1,3,5‐Triamino‐2,4,6,‐Trinitrobenzene (TATB). II. Control of growth by use of high Tg polymeric binders
Authors: Rizzo H. F. , Humphrey J. R. , Kolb J. R. 
Published: May 2005

AbstractThe remarkable safety characteristics of the high explosive 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) are revolutionizing the design and deployment of nuclear weapons. Kel‐F 800 is used as the binder to obtain high‐density, mechanically stable billets of TATB that can be machined into desired shapes. However, repeated thermal cycling between − 54 °C and 74 °C of high density, pure, and plastic‐bonded TATB billets causes a permanent volume expansion (growth) of about 1.5 vol% to 2.0 vol%. Debonding of the Kel‐F 800 binder occurs during growth, causing a reduction in the mechanical properties of the plastic‐bonded explosive. The coefficient of thermal expansion (CTE) of these TATB billets between ambient temperature and 74 °C is 67.0 × 10−6/°C. TATB undergoes a secondary mechanical relaxation just above room temperature, coinciding with the onset of a high CTE, above the glass transition temperature (Tg) of Kel‐F 800. Thus, by judicious selection of a high‐Tg binder, we have essentially eliminated growth, stopped the degradation of mechanical properties after thermal cycling, suppressed the secondary mechanical relaxation, and lowered the CTE to 50.0 × 10−6/°C between ambient temperature and 74 °C.
Predicting High Explosive Detonation Velocities from their composition and structure (II)
Authors: Rothstein L. R. 
Published: May 2005

AbstractAn earlier paper(1) described a simple linear relationship between detonation velocity of 64 ideal C,H,N,O type explosives at their theoretical maximum densities (TMD's) and a factor. F, that is dependent solely upon chemical composition and structure. Based upon available experimental data for nine fluorine‐containing explosives, the equation for calculating the factor has been expanded to include compositional terms for fluorinated compounds. In addition, the reliability of the linear relationship has been further tested against seven more recently published C,H,N,O type explosive experimental detonation velocity data points. The calculated detonation velocity values for all 16 explosives lie within 6.0% of experimental with an absolute error of ± 3.0%.
The ammonium nitrate with 15 WT% potassium nitrate‐ethylenediamine dinitrate‐nitroguanidine system
Authors: Spencer W. , Cady H. H. 
Published: May 2005

AbstractThe phase diagram for the ternary system ammonium nitrate(AN) with 15 wt% potassium nitrate(AN:15KN)‐ethylenediamine dinitrate(EDD)‐nitroguanidine(NQ) has been determined from room temperature to the melting point. The ternary eutectic temperature, measured for a mixture containing 67.24, 25.30, and 7.46 mole% of AN:15KN, EDD, and NQ, respectively, was found to be 98.9 ·°C. The binary phase diagrams for the systems AN:15KN‐EDD, AN:15KN‐NQ, and EDD‐NQ were also determined.
Flame Penetration into Solid Propellant Holes
Authors: Andoh E. , Kubota N. 
Published: May 2005

AbstractThe phenomenon of flame penetration into solid propellant holes has been observed in a nitrogen pressurized strandburner. The phenomenon is largely dependent on the size of the holes, the burning rate (or pressure), and the burned gas temperature. Flame penetration was never observed when the holes were not perforated. The pressure difference between the ends of the hole which is induced by the propellant burning causes the gas to flow into the hole and ignite the interior surface of the hole.
Detonation Properties of 1,3,5‐Triamino‐2,4,6‐Trinitrobenzene when impacted by hypervelocity projectiles
Authors: Delistraty J. , Brandt H. 
Published: May 2005

AbstractThis investigation analyzes the reaction of an insensitive high explosive with binder to hypervelocity impact by four projectiles of two types: rod and plate. The insensitive high explosive is composed of 92.5% 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) and 7.5% Kel‐F 800 binder, a vinylidene fluoride‐chlorotrifluoroethylene copolymer. In this paper, for simplicity, we refer to this composition as “TATB”.Of the the impacting projectiles, three are steel‐rod assemblies ranging in weight from 32.6 g to 34.6 g, and are composed of a steel rod 8 mm in diameter and 19 mm in length, of which 9 mm protrudes from a Polyzelux plastic holder. The fourth is a tantalum‐plate assembly, weighing 23.9 grams and composed of a tantalum plate 24.2 mm in diameter and 1.5 mm in thickness mounted on a Polyzelux holder. The tantalum‐plate experiment provides a highly efficient diverging detonation profile as predicted by similar previous investigations with flyer plates and TATB. The steel‐rod experiments are compared to the tantalum‐plate experiment to determine if detonation has occurred with the steel‐rod impacts.The projectiles are accelerated by a two‐stage, light‐gas gun to velocities in the range of 3.1 km/s to 6.5 km/s (10,171 ft/s to 21,325 ft/s) and have bracketed the detonation threshold of the impacted TATB target. Comparisons of the TATB reaction data to a computer modeling of the experiment show that at 3.06 km/s, the computer model correctly predicts no initiation of detonation; at 4.75 km/s, the computer model correctly predicts a partial detonation; and at 5.67 km/s and 6.53 km/s, both the computer analyses and the experiments give divergent detonations.
On the possibility of Detecting Case/Liner and Liner/Propellant Debonds in a Rocket Motor by means of the ultrasonic multiple reflection pulse echo technique
Authors: Zwijnenburg A. , Korting P. A. O. G. , Reitsma H. J. 
Published: May 2005

AbstractIn order to examine whether and to what extent the ultrasonic multiple reflection technique can be used for detecting case/liner and liner/propellant debonds, measurements were performed on samples sawn from a particular case‐bonded rocket motor consisting of a layer of 2.4 mm steel, a layer of 1,3 mm liner material (a polymer) and a thick layer of composite (AP/PU) propellant respectively. It was found that case/liner debonds could be traced reasonably well; liner/propellant debonds, however, could not be evidenced owing to strong quenching of the ultrasound in the liner. Investigations of the texture of the liner material with the aid of a scanning electron microscope proved the strong quenching in the liner to be mainly due to the presence of many voids with diameters of some 50 μm–200 μm which strongly disperse the sound beam.
Factors Influencing the Pyrotechnic Reaction of Silicon and Red Lead
Authors: Hedger J. T. 
Published: May 2005

AbstractThe delay time of a column of pyrotechnic material when used in a delayed action electric detonator is defined as the time between the application of the initiating electrical impulse and the detonation of the explosive charge of the detonator. The effects of fuel/oxidant ratio and fuel surface area on the delay time have been measured for the silicon/red lead system. From the data obtained it has been possible to identify a possible reaction mechanism for this pyrotechnic composition.
Thermal Decomposition of Guanidinium Perchlorate
Authors: Udupa M. R. 
Published: May 2005

AbstractThermal decomposition of guanidinium perchlorate has been studied by thermogravimetry, differential thermal analysis, mass spectrometry and X‐ray diffractometry. The title compound undergoes crystallographic phase transformation at 180°C before melting at 255°C. It decomposes exothermally into gaseous products in the temperature range 275°C–325°C. The mass spectral results suggest that the compound undergoes thermal decomposition into neutral particles which are then vapourized, ionized and oxidized. The fragment cyanamide is found to undergo trimerization to give melamine.
On the Break‐Up of Shaped Charge Jets
Authors: Haugstad B. 
Published: May 2005

AbstractIt is shown from dimensional arguments that the semi‐empirical jet break‐up formula of Hirsch(1) is consistent with physical models characterized by ideal plasticity (yield stress σ0), the material initial density (ϱ0), strain rate (η0), and jet radius (r0). Similar arguments applied to a one‐dimensional jet stretching model yields the existence of a maximum unstable perturbation wavelength, and fixes its value to within a numerical constant. Within the class of physical models considered the plastic velocity appearing in the Hirsch formula, the incremental velocity between successive fragments of a particulated jet, and the velocity (σ0/ϱ0)1/2 are all related, as originally conjectured by Hirsch.
Application of the Robbins‐Monro method to the sensitivity testing of explosives. II. The experimental practice
Authors: Schilperoord A. A. , Bruckman H. W. L. , Schelling B. A. 
Published: May 2005

AbstractIn this second part of a series of publications dealing with the application of the Robbins‐Monro method to the sensitivity testing of explosives, the experimental aspects are treated. The results of an experimental program with a primer drop‐test apparatus confirmed the efficiency which was concluded from the computer simulation study, also for extreme percentage points. Further a method is described to determine the reliability of the outcome after the execution of the Robbins‐Monro process. It is shown that for an efficient application of the Robbins‐Monro method the level distance which can be adjusted should be about 1/2 to 1/3 of the standard deviation (of a normal distribution) dependent on the percentage point.
Explosives Performance Potential ‐ A New Definition
Authors: Krishna Mohan V. , Tang Tong B. 
Published: May 2005

AbstractA new method for predicting explosive performance potential is suggested. This parameter, which has the dimension of power density, can be theoretically evaluated from three readily available quantities, as the product of the cube root of the volume ratio of detonation products to reactant, heat of detonation, and detonation velocity of the explosive. The calculated performance potential has been found to correlate well with the strength and brisance data for a number of explosives. Experimental detonation pressure gives equally satisfactory correlation; since its measurement is difficult, the approach advocated here is preferable.
Low Pressure Combustion of Composite Propellant
Authors: Schöyer H. F. R. , Korting P. A. O. G. 
Published: May 2005

AbstractThe combustion behaviour of two batches of a new type of composite propellant was investigated in the pressure range between 5 kPa and 915 kPa absolute. A newly developed technique to determine simultaneously the burning rate, combustion efficiency, and the propellant's sensitivity for combustion instability is described together with a specially developed data reduction code. Notwithstanding the low pressure during the experiments no lower deflagration limit could be traced but a Vieille type burning rate law appeared to be applicable for the whole pressure range of interest. A large difference found in the combustion behaviour could be attributed to the fact that the two batches had been manufactured with AP from different suppliers. Combustion efficiency was poor while combustion instability occurred in the whole pressure range.
The Characteristic Temperature Method to Estimate Kinetic Parameters from DTA curves and to evaluate the compatibility of explosives
Authors: Liu Z. R. , Yin C. M. , Wu C. H. Y. , Chang M. N. 
Published: May 2005

AbstractThe thermal analysis technique was used to rapidly evaluate the compatibility of explosives with contacted materials. The three kinetic parameters viz. activation energy E, reaction order n and pre‐exponential factor A were calculated from three characteristic temperatures of a single DTA curve. The compatibility was evaluated from the four parameters E, n and the characteristic temperatures Tm (peak maximum) and To (decomposition starting point on the DTA curve). The results are compared to those obtained from the gasometric method.
Sintox ‐ A New, Non‐Toxic Primer Composition by Dynamit Nobel AG
Authors: Hagel R. , Redecker K. 
Published: May 2005

AbstractA general development of proven composition variants is derived from the historical evolution of primer compositions. Rules and requirements for new developments can be drawn up. On the basis of this knowledge the concept of a primer mixture, containing non‐toxic elements is laid down. An analysis of the air in firing ranges enables a comparison of the emission behaviour of conventional sinoxide ammunition and the new sintox ammunition. (Sintox is a protected trade‐mark (brand name) of Dynamit Nobel AG.)
Decomposition Chemistry of TAGN
Authors: Kubota Naminosuke , Hirata Norimasa , Sakamoto Satoshi 
Published: May 2005

AbstractTriaminoguanidine nitrate (TAGN) is a unique energetic material which produces relatively low molecular weight combustion products. TAGN is characterized by the oxidizer fragment “HNO3” that is attached by an ionic bond in the molecular structure. In this study, various types of experiments were conducted in order to elucidate the physicochemical decomposition process of TAGN. The exothermic rapid reaction observed at the early stage of the decomposition is the process representing the nature of energetics of TAGN. This exothermic reaction occurs immediately after the endothermic phase change from solid to liquid. Since the weakest chemical bond consisting in the TAGN molecule is the NN bond (159 kJ/mol), the initial bond breakage should be the amino groups and the NH2 radicals split off. The energy released by the dissociation of the NH2 radicals (104.3 kJ/mol) is the heat produced at the early stage decomposition of TAGN. Thus, the burning rate of TAGN is considered to be dominated by the dissociation of the NH2 radicals. It must be noted that the burning rate of TAGN is almost double that of HMX even though the energy contained in the unit mass of TAGN is less than that of HMX. The HNO3 attached to the molecular structure of TAGN is not the fragment to produce the exothermic rapid reaction observed at the early stage decomposition process.
Thermal Decomposition of Energetic Materials XXVIII. Predictions and results for nitramines of bis‐imidazolidinedione: DINGU, TNGU and TDCD
Authors: Oyumi Y. , Brill T. B. 
Published: May 2005

AbstractStructural/thermal decomposition relationships are assessed in this project. The relative concentrations of the first observed, infrared‐active gas products generated by fast thermolysis (dT/dt = 110 K/s) of 2,5‐dioxo‐1,3,4,6‐tetranitro‐tetrahydrocyclobutan[1,2‐d : 3,4‐d′]diimidazole (TDCD) and 1,3,4,6‐tetranitroglycoluril (TNGU) were successfully predictable from structure/thermal decomposition relationships. The predictions for 1,4‐dinitroglycoluril (DINGU) were only partly successful. The departures from expection appear to originate from the different degree of stability of the non‐energetic backbone of these molecules. The dependence of the first‐observed gas products on pressure from these molecules was qualitatively predicted from the nature of the products liberated at atmospheric pressure.
Critical energy criterion for the Initiation of Explosives by Spherical Projectiles
Authors: James H. R. , Hewitt D. B. 
Published: May 2005

AbstractEvidence is given of a fundamental difference between the response of bare explosive to the impact of a flat‐nosed rod, and the response to a sphere or round‐nosed rod. For relatively insensitive explosives such as Composition B, a spherical projectile, in contrast to a flat‐nosed rod, can have a range of impact velocities that produce a blast output which falls short of the output expected from a full detonation. It is postulated that this effect is caused by the divergent flow behind the initial impact shock created by the sphere. Without such divergence it is assumed that these impacts would produce full detonation. Consequently thc critical energy criterion for spherical impacts should be applied to the non‐reaction/reaction boundary and not the reaction/detonation boundary. This is shown to give constant values of critical energy for different sizes of sphere impacting the same explosive, and to give similar energy values to those obtained from impacts of flat‐nosed rods.
A rapid non‐aqueous titrimetric estimation of ammonium perchlorate in pyrotechnic compositions
Authors: Ninan K. N. , Madhavan A. , Sadhana R. 
Published: May 2005

AbstractA rapid and safe nonaqueous titrimetric method has been developed for the estimation of ammonium perchlorate (AP) in pyrotechnic compositions. It uses tetrabutyl ammonium hydroxide as titrant and dimethyl formamide, pyridine or dimethyl sulfoxide as solvent. The validity of the method has been confirmed using pure AP and AP mixed with known quantities of aluminium, zirconium or boron. Both visual (thymol blue indicator) and potentiometric methods are employed in the estimation.
Study on the Mechanism of the Acetolysis of Hexamethylenetetramine
Authors: Ju Chen , Shaofang Wang , Fuping Li 
Published: May 2005

AbstractThe acetolysis of hexamethylenetetramine (hexamine) to give 3,7‐diacetyl‐1,3,5,7‐tetraaza‐[3.3.1]‐bicyclononane (DAPT), 1,3,5,7‐tetraacetyl‐1,3,5,7‐tetraazacyclooctane (TAT) and 1,3,5‐triacetyl‐1,3,5‐triazacyclohexane (TRAT) was studied. NMR tracing showed the courses of acetolysis, the effects of the reaction conditions on its directions, and the evidence that the methylene degraded from hexamine was the formaldehyde. Based on these results, the acetolysis mechanism was proposed. The comparison of the acetolysis with the nitrolysis of hexamine showed that the two reactions experienced the similar courses, which would be useful for searching out a way to improve the yield of 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX) in Bachmann process.
Investigation of Liquid Gun Propellants: Electrical ignition of LGP 1846
Authors: Klingenberg G. , Rockstroh H. , Knapton J. D. , Despirito J. , Frieske H.‐J. 
Published: May 2005

AbstractProgress achieved in the study of the electrical ignition of the hydroxylammonium nitrate(HAN)‐based liquid gun propellant LGP 1846 is described. The goal of the work is to develop an igniter system suitable for regenerative liquid propellant guns. Several igniter configurations of the one‐ as well as the two‐stage types designed by the Ballistic Research Laboratory and the Fraunhofer‐Institut EMI‐AFB, have been tested. Voltage and current as well as the pressure histories were recorded. Calculations of electrostatic field distributions discussed here were obtained by a finite element code implemented at Dynamit Nobel. The theoretical analysis yielded alternative electrode designs for future testing. In addition, a specially designed igniter chamber equipped with sapphire windows was used at EMJ‐AFB to study the fundamentals of the electrical discharge by means of high‐speed photography.
Correlations between Reaction Dynamics Experiments and the Detonation of Explosives
Authors: Walker Franklin E. 
Published: May 2005

AbstractData and information reported from reaction dynamics experiments appear to correlate very well with data and calculations from the detonation of chemical explosives. Comparisons are presented of particle and vibratiional velocities, atomic and molecular kinetic energics, time scales for reaction, bond strengths, and shock velocity data. A rationale and method for determining detonation velocities and evidence for rate‐determining kinetics from the reaction dynamics data and molecular dynamics calculations are presented. It is concluded that first order values for detonation characteristics can be calculated from the energy and reaction rate factors considered, and that the methods of reaction dynamics discussed could be applied to the study of probable detonation reactions to give refined quantitative values for detonation processes.
Isomer distribution of nitro derivatives of diphenylamine in gun propellants: Nitrosamine Chemistry
Authors: Curtis Neville J. 
Published: May 2005

AbstractThe derivatisation of diphenylamine (DPA) in single base gun propellants was studied as a function of aging at 80°C. The relative proportions of 2‐nitro DPA and 4‐nitro DPA varied from 32 : 68 to 63 : 37 according to propellant type. Preferences for para substitution were seen in experimental lots “stabilized” with 2‐nitroDPA, 4‐nitroDPA and N‐nitrosoDPA. Increasing water content resulted in higher preferences for ortho substitution. 4‐NitroDPA is a better stabilizer than 2‐nitroDPA. Model studies performed using nitro substituted N‐nitrosamines show that para substitution is preferred in boiling acetic acid. Mechanisms for the conversion of N‐nitrosamines into isomeric nitro derivatives are discussed with relation to the model studies and the behaviour in propellants. Detailed experimental procedures are given for the preparation of N‐nitrosamines.
Uncontrolled ignition mechanisms in liquid propellant guns
Authors: Knapton John D. , Coffee Terence P. 
Published: May 2005

AbstractTwo potential mechanisms are described which may result in uncontrolled ignition in liquid propellant regenerative guns. The two mechanisms are related to reverse burn in the injection orifice. One mechanism is associated with a poorly designed injection orifice, which may result in a low discharge coefficient, boundary layer separation, and flame holding in the orifice. The second mechanism is related to the response of the liquid propellant reservoir to the ignition pressure, which may excite pressure oscillations in the reservoir resulting in a reverse orifice pressure gradient. Both mechanisms may result in a reverse orifice burn or flash back to the reservoir.
Ignition Mechanisms in Monopropellants
Authors: Messina Neale A. , Ingram Larry S. , Tarczynski Marek , Knapton John D. 
Published: May 2005

AbstractThe sensitivity of liquid monopropellants is examined when subjected to compression ignition, including the case of purposeful sensitization with air bubbles; and frictional heating. The monopropellant is a hydroxylammonium nitrate (HAN)‐based propellant. Conditions are identified which will likely result in ignition from rapid compression. Ignition from frictional heating associated with hydroynamic flow is less certain, however attempts to model this phenomenon theoretically have been made.