bluuebunny/crossref_metadata_2025_split huggingface dataset:
CTPB Cure Studies‐effect of experimental variables on epoxide cure and properties of gumstocks
Authors: McGuchan R. , Spickernell G. J. 
Published: December 2004

AbstractThe effects of various processing and compositional variables the cure rate and mechanical properties of epoxide‐cured CTPB gumstocks have been evaluated.Viscosity changes during the initial stages of cure and tensile properties of fully cured gumstocks are sensitive to the nature and functionality of the epoxide curative even though comparisons are made at epoxy/carboxyl equivalence ratios giving the same density of crosslinks. Batch‐to‐batch variations in prepolymer structure, functionality and impurities also are important. In particular, glutaric acid impurity inhibits the cure, the effect being very marked when the mixing procedure involves heating the prepolymer and catalyst together before the addition of epoxide.Effects due to plasticisers and ammonium perchlorate filler also are reported. The mechanical behaviour of gumstocks and of corresponding filled systems (propellants) show little correlation.
New Aspects in Ferroelectric Energy Sources for Impact Fuzes
Authors: Bauer F. , Vollrath K. 
Published: December 2004

AbstractIn order to find materials with increased specific electrical energy, especially for impact fuzes, the irreversible conversion of mechanical to electrical energy in ferroelectric ceramics of the Pb(Zr1‐xTix) O3 type with a considerable proportion of zirconium is studied. The depolarization of the ceramics is measured for shock compressions between 0 and 30 kbar. The maximum electrical energy, obtained at about 18 kbar, is of the order of 1.8 J/cm3 with Pb(Zr0.965Ti0.035)03 + 1% Nb2O5 and of the order of 0.8 J/cm3 with a Pb(Zr0.54Ti0.46)03 + 1% Nb205. As an example for application, the initiation of a 3.5 ω bridge wire PETN detonator is described.
Chemistry of Titanium, Zirconium and Thorium Picramates
Authors: Srivastava R. S. , Agrawal S. P. , Bhargava H. N. 
Published: December 2004

AbstractPicramates of titanium, zirconium and thorium are prepared by treating the aqueous sulphate, chloride and nitrate solutions with sodium picramate. Micro‐analysis, colorimetry and spectrophoto‐ metry are used to establish the compositions (metal : ligand ratio) of these picramates as 1 : 2 (for titanium and zirconium) and 1 : 4 (for thorium). IR studies indicate H2N → Me coordination (where Me denotes the metal). A number of explosive properties of these picramates point to the fact that the zirconium picramate is thermally more stable than the picramates of titanium and thorium.
Technology of the Screw‐Extrusion Process for the manufacture of double‐base rocket propellants
Authors: Homburg A. , Brachert H. 
Published: December 2004

AbstractDescription of a continuous, remote‐controlled and largely automated processing method for double‐base solid propellants for the propulsion of rockets. The base materials are mixed as an aqueous batch and processed into a wet mix paste with concurrent homogenization. Kneading is a continuous and automatic process performed by disc kneaders. Compression to the granulate, as the intermediate product, is also a continuous and automatic two‐stage process performed in twin‐screw extruders with automatic mixing of the batch quantity into a homogeneous product between these two operations. Before the last operation, compression molding, the propellant mix which is continuously dewatered in the various operations, is dried to the moisture content required for the end product and, in the last stage, it is again continuously and automatically compressed in twin‐screw extruders to form the propellant grain.This process is distinguished by the high homogeneity of the end product, high reliability, rational and material‐saving processing and a broad field of application.
Thermal Decomposition Studies on Hexahydro‐1,3,5‐trinitro‐s‐triazine (RDX) by differential scanning calorimetry
Authors: Kishore K. 
Published: December 2004

AbstractThermal decomposition of KDX has been studied by Differential Scanning Calorimetry. KDX was found to decompose significantly below its melting point. The rate and activation energy (E) of the decomposition in the open and closed‐pan conditions were different. Under closed‐pan conditions the products seem to catalyse the decomposition. The E value for the decomposition of KDX (under open‐pan conditions) both under isothermal and dynamic conditions was estimated to be (41±2) kcal/mol. The method of E estimation was free from kinetic assumptions. The order of reaction was found to be 0.6.
The High Velocity Detonation of Single Crystals of α‐Lead Azide
Authors: Chaudhri M. M. , Garrett W. L. , Sandus O. , Slagg N. 
Published: December 2004

AbstractA high speed photographic study at a framing rate of 5 × 106 s−1 has been made of the propagation of high velocity detonation in single crystals of α‐lead azide. Crystals of cross section 2 mm × 2 mm and greater detonated at∼8000 m/s whereas those of smaller sizes (∼1 mm) deflagrated at ∼ 3000 m/s. Finally, the mechanism of propagation of high velocity detonation has been discussed.
Propellant Evaluations by Free Energy Minimization through Random Search
Authors: Swaminathan V. 
Published: December 2004

AbstractThe present paper describes a method for determining the equilibrium composition of the combustion products and the performance of propellants by using the Free Energy Minimization Technique. This minimization is sought to be carried out by a direct random search technique and systematic reduction of the size of the search region. The problem was programmed on the IBM 360/ Model 44 Computer in FORTRAN IV and rhe results for a typical metallized propellant are shown in the paper.
La Migration de la Nitroglycérine dans les Inhibiteurs de Poudres à Double‐base
Authors: Caire‐Maurisier M. , Tranchant J. 
Published: December 2004

AbstractLes inhibiteurs de combustion pour blocs d'autopropulsion en propergols double‐base à la nitroglycerine sont generalement des polyesters. On montre comment et pourquoi I'ester nitrique migre de la poudre vers I'inhibiteur au cours du vieillissement, et on etudie des moyens pour eviter cette migration.
Determination of Moments of Inertia and Rotational Unbalance of a Projectile and the resulting forces on and deflections of the muzzle
Authors: Leisinger K. F. 
Published: December 2004

AbstractAsymmetries in the mass distribution of a projectile lead to rotational unbalance. A technique for determining this unbalance will be described. One must distinguish between static unbalance, where the centre of gravity does not lie on the axis of rotation, and dynamic unbalance, where the axis of rotation deviates from that of one of the principal moments of inertia. On firing, due to the spin of the projectile, both kinds of unbalance lead to a bending of the barrel. This is calculated using a simple theoretical model and measured values of moments of inertia and unbalance.
EXTEST International Study Group for the standardization of the methods of testing explosives. (Formerly European commission for the standardization of the tests of explosives)
Authors: Persson P. A. 
Published: December 2004

AbstractThe report gives an account of the discussions and the agreements reached during the 7th meeting of the Commission together with the full texts of the 18 technical papers presented to the meeting.Recommended standards and testing procedures were finally approved for the following:

Ballistic mortar

Transmission of detonation of ion‐exchanged explosives

Test detonators with 0.6 g and 0.25 g PETN

Method of testing the initiating strength of detonators.

The following new themes were included in the plan for the next period of work of the Commission:

Toxic fumes from explosives in blasting

Initiation and stability of detonation of slurry and water gel explosives under different conditions

Sensitivity of slurry and water gel explosives

The underwater explosion test

Deflagration and transition from deflagration to detonation.

The Commission agreed on a change of its name. The new name will be: „EXTEST International Study Group for the Standardization of the Methods of Testing Explosives”︁. A suggestion for the Commission to seek a form for association with other international corporative bodies such as the International Organization for Standardization (ISO), suitable for furthering the objectives of the Commission, was discussed and will be further investigated.The next meeting of the Commission will be in 1978 in Czechoslovakia.
Résultats Particuliers d' Essais sur Explosifs en Gels aqueux sensibilisés à l' Aluminium
Authors: Goffart P. R. 
Published: December 2004

AbstractLes slurries sensibilisés à l'aluminium, produits par simple mélange d'une solution aqueuse de sels oxydants (nitrates inorganiques) avec des combustibles à l'état sec, peuvent être amorçcables au détonateur.Leur préparation se complète par addition d'agents de réticulation et d'allègement, qui agissent à bref délai après mélange et chargement en étui d'encartouchage ou en trou de mine: la bouillie se transforme alors en gel aqueux emprisonnant une multitude de bulles de gaz, qui sont autant de discontinuités de milieu.On pourrait croire que ces bulles d'allègement sont indispensables pour conférer la sensibilité au détonateur, comme c'est d'ailleurs généralement le cas pour les explosifs classiques ou les slurries sensibilisés par nitrates organiques.Nous montrons par résultats expérimentaux ayant une signification statistique, que les bulles gazeuses générées au dernier stade de la fabrication permettent certes d'ajuster la densité du gel à l'aluminium, mais que vitesse de détonation et également aptitude à détoner (au sens de sensibilité au détonateur) sont toutes deux nettement moindres lorsqu'il s'agit du gel comparé à sa bouillie‐mère d'origine, non encore réticulée ni allégée.Cette particularité des slurries sensibilisés à l'aluminium pourrait être en rapport étroit avec leur remarquable sécurité au pompage.
Underwater Explosion
Authors: Paterson S. , Begg A. H. 
Published: December 2004

AbstractThe facilities and methods in use at Nobel's Explosives Company Ltd. for assessing explosive potential by the underwater method are described. Quantities measured include the velocity of detonation, the bubble period, the maximum bubble radius and the pressure‐time signature of the shock wave. From these, shock and bubble energies can be deduced and used as figures of merit for the material under test.Results obtained in this way for a variety of types of explosive are summarized and their significance as an index of performance is discussed.
Experimental investigation into the L* instability of double base rocket propellants
Authors: Schöyer H. F. R. , De Boer R. S. 
Published: December 2004

AbstractIn a continuous joint research program, the Department of Aerospace Engineering of DUT and the Technological Laboratory TNO investigate unstable combustion of solid rocket propellants. Some results of this research program are discussed here. The oscillatory combustion phenomenon is discussed qualitatively, and the interaction between the acoustics of the cavity and the pyrolysis of the propellants is explained. For the investigation of the low‐frequency unstable combustion, a special device, the L* burner, is very suited. A description is given of the two L* burners of different size, which were used in the experiments discussed here. Reproducible ignition is of the utmost importance to conduct these tests. Various ignition methods have been tried and are described together with a very successful one, which was evaluated and finally selected. The experimental results of JPN and ARP propellant experiments are discussed extensively. Oscillatory combustion as well as chuffing has been observed, and it turns out that both phenomena are related to the L* and pressure. As L* burners of different sizes were used, it was possible to estimate the damping, and hence the propellant growth constant. On the basis of the results of these experiments it seems most likely that the damping is volumetric. It has been discovered that for a very large pressure range (∼ 3 MPa) the frequency of the oscillations is linearly dependent on the mean pressure, while at low pressures (<1 MPa) oscillations with a higher frequency, also dependent on the mean pressure, are observed. These observed pressurefrequency correlations are the same for the two L* burners of different size, and hence it may be concluded that these correlations are not affected by the dimensions of the motor cavity.
A New Method for Cast‐Loading Mixtures of Explosives
Authors: Witt W. , Sabranski U. 
Published: December 2004

AbstractA new method for cast‐loading of explosive charges is described. Up to now cooling was used to solidify the melt of the explosive. In this method the state of the explosive is changed by applying pressure which causes an immediate rise of the melting point according to Clausius‐Clapeyron's equation. The total melt solidifies immediately and uniformly. The method has the advantage that voids are avoided and short loading times are obtained if the melting point is raised in this manner to the temperature momentarily present in the explosive.
A Design Criterion for Permissible Water Gel Explosives
Authors: Krishna Mohan V. , Srinivas M. A. 
Published: December 2004

AbstractThis paper presents an analysis of the relationship between oxygen balance, inert content, computed detonation parameters and incendivity for several water‐gel explosives. A mathematical technique has been developed for correlating compositional details and the permissibility test result for a number of existing compositions. The analysis covers two types of explosive compositions and three categories of permissibility tests. Using energy of detonation, oxygen balance and percentages of water and sodium chloride in the composition, this technique is able to consistently predict the permissibility test result with less than 10% exceptions. It is felt that this method will facilitate the design of new explosive formulations which have a high probability of success in permissibility tests.
Rapid Determination of Nitroguanidine and nitrate ion in the spent sulfuric acid
Authors: Chen T. H. 
Published: December 2004

AbstractA rapid method for simultaneous determinations of nitroguanidine and nitrate ion in the spent sulfuric acid has been developed. This method consists of merely diluting an aliquot of sample with water and measuring the absorbances of nitroguanidine and nitrate ion at 265 nm and 203 nm, respectively. In the concentration ranges studied, average accuracies of better than 1% and 2% were obtained for nitroguanidine and nitrate ion, respectively. The precision was better than 1% in both cases.
Indirect Determination of Water in Nitroglycerin‐Nitrocellulose Pastes by gas‐liquid chromatography
Authors: Blanco J. A. , Rucci A. O. , Revuelto S. C. , Dubini A. A. , Gonzalez R. A. 
Published: December 2004

AbstractA gas‐liquid chromatographic procedure was developed in connection with the determination of water in nitroglycerin‐nitrocellulose pastes. The method is based on the reaction of water with 2,2‐dimethoxypropane and its conversion to acetone which is subsequently determined. The technique is simple, rapid, and shows good accuracy and precision.A simplified method, which is less accurate but does not involve chromatography, is also proposed.
Relation entre La Structure Electronique et la Sensibilité au Choc des Explosifs Secondaires Nitrés. III. Influence de l'environnement cristallin
Authors: Delpuech A. , Cherville J. 
Published: December 2004

AbstractOn étudie l'influence des interactions cristallines sur les paramètres moléculaires corrélés à la sensibilité au choc lors de précédents travaux. Les résultats obtenus permettent de mieux préciser les rǒles respectifs de la molécule et du cristal lors de l'initiation de la détonation. Ils montrent que dans ce domaine, les conclusions tirées de calculs effectués sur une molécule isolée dans sa conformation cristalline sont valables pour le cristal entier.
A model explaining the Rule for Calculating the Break‐up Time of homogeneous ductile metals
Authors: Hirsch E. 
Published: December 2004

AbstractIt was shown in a previous paper(1) that the break‐up time of homogenious ductile metals which elongate due to explosions, is equal to the sample's smallest initial dimension (thickness) divided by the velocity Vpl which characterizes the metal. It is attempted to explain this rule by suggesting a break‐up mechanism where holes caused by a pile‐up of vacancies are formed at the metal surface and gradually increase until breaking it. This model also predicts the existence of a strain rate threshold below which other mechanisms dominate the break‐up process. Its validity is supported by experimental evidence which is also presented.
Role of the friction coefficient in the frictional heating ignition of explosives
Authors: Andersen W. H. 
Published: December 2004

AbstractAn expression is developed for the friction coefficient of a material in terms of the parameters that control the friction shear. This expression in conjunction with the frictional heating equation describes the hot spot temperature produced in a friction event. Hot spot temperature increases with an increase in the particle size and shear strength of the explosive material, with an increase in the (shock) loading pressure and friction velocity, and with a decrease in material thermal conductivity. The equations are discussed in terms of their implications regarding the factors that control the sensitivity of an explosive or propellant to frictional heating under various conditions, and the results of experimental studies given in the literature.
Structure moléculaire des dérivés nitrés aromatiques. IV. Etats électroniques singulets du 1,3,5‐triamino‐2,4,6‐trinitrobenzène (TATB) dans la symétrie D3h
Authors: Leclercq J. M. , Lavenir E. , Leclercq J. , Boileau J. , Odiot S. , Blain M. 
Published: December 2004

AbstractUne coupe des hypersurfaces d'énergie potentielle, le long de la coordonnée de symétrie correspondant au déplacement totalement symétrique des trois groupes NO2, est présentée pout l'état fondamental et les huit premiers états électroniques singulets excités du modèle D3h du TATB. Une suite de calculs auto‐cohérents ab initio (STO‐3 G) de l'énergie de l'état fondamental a été effectuée. Une étude semi‐empirique CNDO/S a permis d'estimer, d'une part la corrélation électronique dans cet état, d'autre part les écarts énergétiques entre les états excités singulets et le fondamental.
An Optical System for Measuring the Burning Rate of Solid Propellant Strands
Authors: Eisenreich N. , Kugler H. P. , Sinn F. 
Published: December 2004

AbstractAn optical system is described for measuring the burning rate of solid propellant strands. It consists of a bomb equipped with quartz windows, an objective, a photo diode array and a data acquisition and processing unit. A Simultaneous observation of the burning in possible by other optical and spectroscopic methods.The system is tested by recording the pressure dependence of the burning rates of typical propellants. The results are compared to those obtained by the standard Crawford method. The advantages of the optical system are due to the easier handling in sample preparation and the assessment of a distribution of the burning rate.
Experiments of Initiation of Covered, but Unconfined HE Charges under different test conditions by shaped charge jets
Authors: Held M. 
Published: December 2004

AbstractThe initiation behavior of TNT/RDX 35/65 high explosive charges under the impact of the jet from a 44 mm diameter shaped charge with 7.8 mm/m̈s jet tip velocity, which has previously perforated a 100 mm thick barrier is reported. In these tests,

the high explosive charge under test was divided into different sections by transverse air gaps, with the first section being in contact with the barrier, or
the 100 mm thick barrier was sub‐divided in such a way that one part of it was in contact with the high explosive charge under test, or
various air gaps, ranging from 0.5 mm to 450 mm, were made between the acceptor charge and the barrier.
The Initiation Threshold Sensitivity of HNS Explosive as a Function of its Grain Size
Authors: Hasman E. , Gvishi M. , Solomonovici A. 
Published: December 2004

AbstractThe initiation threshold sensitivity of HNS versus explosive grain size has been measured, using an electric gun, with two flyer thicknesses. The initiation threshold, (kinetic energy of flyer plate), versus explosive grain size shows that the threshold curve increases dramatically at grain size over 5.4 m̈m (for flyer thickness 76.2 m̈m at explosive density 1.6 g/cm3). Minimum critical energies were calculated to be 12.15 ± 0.5 J/cm2 and less than 7.0 J/cm2, for flyer thicknesses 76.2 m̈m and 20.0 m̈m, respectively.
Combustion Wave Structure of AP Composite Propellants
Authors: Yano Y. , Miyata K. , Kubota N. , Sakamoto S. 
Published: December 2004

AbstractThe combustion mechanism of ammonium perchlorate (AP) composite propellants were studied. The oxidizer‐rich propellants tested were made with excess concentrations of AP particles. The pressure deflagration limit of propellant decreases with increasing the concentration of binder. The combustion wave consists of two reaction regions I and II: the region I is the zone of AP monopropellant flame and the region II is the zone of diffusion flame. The heat flux feedback from the gas phase to the burning surface increases as pressure increases, and the heat flux is responsible for the burning rate characteristics.
Measurement of the smoke density of endburning double base propellant grains before and after burnout
Authors: Pröbster M. , Huber W. , Strecker R. , v. Taeuffenbach G. 
Published: December 2004

AbstractThe formation of smoke during firing of DB‐endburners is dependant on the chemical composition of the employed inhibitor. Measurements, which correlate the observed attenuation of light in the exhaust gas before and after burnout with the composition of the inhibitor, are described. The binders used were polyurethane resins with oxamide as filler and unsaturated polyester with Lithopone, respectively.
Chemiluminescence Study on Thermal Decomposition of Nitrate Esters (PETN and NC)
Authors: Kimura J. 
Published: December 2004

AbstractMeasurements of chemiluminescence (CL) during heating of nitrate esters (PETN and NC) have been conducted in the temperature range between 40 °C and 90 °C in an inert atmosphere. Faint light was emitted from the condensed‐phase in steady‐state fashion. This new finding implies that the thermal decomposition of nitrate esters is accompanied by some oxidation reactions. Spectral analysis of the CL showed that the light‐emitting species will be the first excited triplet of carbonyl‐containing products and singlet oxygen. The low‐temperature CL phenomena observed for PETN and NC are represented by Arrhenius law, providing the activation energy of 63 kJ/mol (= 15 kcal/mol). Kinetic analysis of the CL has led to the result that the formation of peroxy radicals, which can be produced by oxidation of the primary products of nitrate ester bond (RONO2) cleavage, predominates a consecutive series of radical reactions of the CL.