bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Alumina Trihydrate Filler on semiflexible unsaturated polyester resin‐4 and inhibition of double‐base rocket propellants
Authors: Agrawal J. P. , Chowk M. P. , Satpute R. S. , Kulkarni K. S. 
Published: May 2005

AbstractThe use of unsaturated polyesters for inhibition of double‐base rocket propellants has become popular in recent years. A direct bonding inhibition system termed as semiflexible unsaturated polyester resin‐4 has been recently developed and reported by us. It has been reported in literature that the use of some fillers such as antimony trioxide, titanium dioxide, lithophone, alumina trihydrate etc. impart better mechanical and heat resistance properties. The effect of 10% to 60% of alumina trihydrate (Al2O3 · 3 H2O) on semiflexible unsaturated polyester resin‐4 in respect of gel time, exotherm peak temperature, tensile strength, %‐elongation, nitroglycerin absorption, water absorption, heat resistance and flame retardance has been studied and the result obtained have been discussed. It is observed that 30% of alumina trihydrate imparts desirable properties. The 108 mm and 148 mm‐diameter propellant sustainers inhibited with resin‐4 containing 30% alumina trihydrate and conditioned at ambient, sub‐zero temperature (−40°C for 18 hr) and high temperature (+50°C for 18 hr) were statically evaluated. The pressure‐time profiles at all temperatures have been found to be flat and neutral which infer that the inhibition system works satisfactorily.
Thermoanalytical Investigation of Stored Ammonium Nitrate doped with diammine copper‐(II)
Authors: Engel W. 
Published: May 2005

AbstractAmmonium nitrate doped with diammine copper dinitrate and stored for 10 years was reinvestigated by DTA and TMA. The phase transition IV/II and IV/III, which are of interest for the practical use, still occur above 50°C. In spite of moisture contents between 0.4% and 1.4% no caking was observed.
Determination of the Material Quality of Copper Shaped Charge Liners
Authors: Held M. 
Published: May 2005

AbstractWhen several liners as well as high explosive charges are produced in identical and reproducible ways resulting in identical or at least similar sizes and geometries, differences in the total lengths of the shaped charge jets will indicate differences in copper quality.This paper outlines guidance for taking flash X‐ray pictures of shaped charge jets for this purpose, and for an analysis of the pictures at least for a comparative assessment. The penetrating capability can be derived from the particulation times.
Combustion of HMX‐CMDB Propellants (II)
Authors: Yano Y. , Kubota N. 
Published: May 2005

AbstractThe burning rate characteristics of HMX‐CMDB propellants were examined as a function of HMX concentration. In the region of low HMX concentration, below about 50%, the burning rate decreases with increasing the HMX concentration. However, in the region of high HMX concentration, above about 50%, the burning rate increases with increasing the HMX concentration. When the measured results are extrapolated to the 100% HMX concentration, it is recognized that the burning rate approaches the burning rate of an HMX single crystal. The burning rate analysis indicates that the effect of the addition of HMX particles within double‐base propellants on burning rate is determined by the reaction rates in the gas phase and in the condensed phase. The gas phase reaction rate in the fizz zone decreases monotonously as the HMX concentration increases. On the other hand, the heat of reaction at the burning surface increases as the HMX concentration increases. The experimental results indicate that the burning rate with low HMX concentration is mainly controlled by the gas phase reaction rate and the burning rate with high HMX concentration is mainly controlled by the condensed phase reaction rate.
Study of an Explosive‐Driven Metal Plate
Authors: Yadav H. S. , Kamat P. V. , Sundaram S. G. 
Published: May 2005

AbstractEquation of motion of an incompressible metal plate, accelerated by a plane detonation wave, has been solved for a general value of adiabatic exponent ß of detonation products to investigate its effect on terminal velocity of the plate. It has been found that the plate velocity increases with decreasing value of ß. The magnitude of this effect has been found sufficient to determine adiabatic exponent of detonation products from the measurement of flyer plate velocities at different C/M ratios.Velocities of metal plates, hurled by contact explosion of high density explosives, have also been measured with oscillographic technique by using an experimental setup which is insensitive to air shocks. The plate velocities measured by such an experimental setup have been found in good agreement with theoretical ones.
The Orthogonal Synchro‐Streak Technique as a Diagnostic Tool, particularly for shaped charge jets
Authors: Held M. 
Published: May 2005

AbstractThe test set‐up for recording a shaped charge jet by the orthogonal synchro‐streak technique (OSST) is described. By means of an example it is shown how the information on the deviation of the jet elements in X, Y‐ and in polar co‐ordinates as well as that on the length of the jet and on the times of particulation can be extracted from the streak record.
The Influence of the Variation of Combustion Chamber Volume under pressure load on the determinational of thermodynamic characteristics of solid propellants in pressure bombs
Authors: Grune D. 
Published: May 2005

AbstractDetailed combustion studies in high‐pressure bombs show that the measured maximum gas pressures are always lower than theoretically calculated values and that these differences increase more than proportionally with rising loading densities. By means of experiments and calculations we show that a considerable part of the pressure difference is brought about by the expansion of the combustion chamber during pressure load.The expansion of the combustion chamber is responsible for pressure measurements that are about 5% too low at currently used pressures of 500 MPa. Furthermore the covolume yields an error of about 12% if the constants of the Abel state equation are determined using the standardized method for loading densities of 0.20 g/cm3 and 0.22 g/cm3. The error of the force constant remains under 1%.As the values determined from pressure bomb measurements are to be introduced into further calculations, they must be corrected according to the combustion chamber expansion, or new measuring methods will be necessary.
A Correction for Ejection Angles of Fragments from Cylindrical Wareheads
Authors: König P. J. 
Published: May 2005

AbstractThe problem of end effects influencing the ejection angles of fragments near the ends of cylindrical warheads is approached semi‐empirically. A correction term is added to the Taylor angle, based on the accepted concept that the reduced fragment velocities near the ends of a warhead are due to release waves in the detonation gas. Acceptable agreement between experiment and prediction is found for available experimental data. The results indicate that the accelerative drag due to the axially‐outward component of the release‐wave gas flow over the fragments dominates the divergence of the fragments for prefragmented casings, the axial pressure drop playing a minor part, while the reverse seems to be true for the divergence of fragments from solid casings.
Combustion Mechanism of Double‐Base Propellants with lead burning rate catalysts
Authors: Youfang Cai 
Published: May 2005

AbstractOn the basis of relevant experimental phenomena and results, which also include the results on the domain of non‐propellant combustion, this paper has determined basic reactions caused by lead burning rate catalysts in the combustion process and their approximate reaction temperature. In the presence of carbonaceous matter on the burning surface the partial NO is reduced to N2 through six reactions occurred on the carbonaceous matter instead of the reaction between NO and CO. As a result of changing the reducing path of a part of NO the burning rate rises through increasing the temperature gradient in the fizz zone at the burning surface. The reactions between PbO and C and between PbO and CO check the burning rate to rise through expending carbonaceous matter on the burning surface and causing char particles to “fly off” the burning surface. The super‐rate, plateau and mesa effects are perfectly explained with these reactions and the fundamentals of heat transference. The production of the effects arises from the competing of two actions to increase burning rate and to check the burning rate enhancement of lead burning rate catalysts and the effect of the pressure on the burning rate. Because of the fact that the chance to form carbon nuclei and the time of the carbon deposit, the covering ratio of the carbonaceous matter on PbO particles, and the temperature increasing rate and the lagging temperature difference in C‐PbO interfaces depend on the pressure, the ability by the reaction between PbO and C and between PbO and CO checking the burning rate to rise makes a great difference in different ranges of the pressure. In addition, according to the combustion mechanism advanced in the paper the effects of the physical and chemical properties of lead burning rate catalysts, especially their ability to absorb the ultraviolet light, on the rate‐increased values and the pressure ranges of the plateau and the mesa regions have been expounded.
Calculations of Derivative of Second Virial Coefficients based on the exp‐6 intermolecular potential
Authors: Xiong Wu , Jian Sun 
Published: May 2005

AbstractThe quantity of the partial derivative of second virial coefficients with respect to temperature in reduced form, T*∂B*/∂T* has been computed for an exp‐6 intermolecular potential

The results are tabulated over the reduced temperature range T* from 0.4 to 400, and for seven values of the parameters α from 12 to 15. The outputs lead us to lay the foundation for the applications of the theoretical virial type equation of state (6) like VLW using the best form exp‐6 for high pressure studies.
Continuous automated production facility for the manufacture of single‐base propellant powders
Authors: v. Helle C. J. 
Published: May 2005

AbstractThe design‐features of the first continuous single‐base propellant powder plant in the Western Hemisphere are summarized in this report. The highlights: less investment is required to install this simplified manufacturing process. Unmanned automated operations assure improved product quality, lower operating cost, and better safety conditions. As a result of an advanced design the plant is simple, easy to operate, very versatile, and flexible to accommodate changes.
Modification of the Physical Properties of an Extruded Double‐Base Propellant following solvent vapour exposure
Authors: Barter I. , Newell A. , Privett G. 
Published: May 2005

AbstractSamples of a rolled double‐base propellant were exposed to acetone vapour and the rate of solvent uptake observed. The solvent was subsequently removed and dynamic mechanical and extensometer measurements were made on the dried samples.The percentage elongation at break and the ultimate tensile strengths of the samples after solvent treatment were considerably above that of the control samples. The solvent uptake modified the relaxation behaviour of the samples and consequently the values of Young's modulus within the temperature range 30°C to 60°C. The solvent uptake was found to be non‐Fickian.Samples that had been thermally annealed prior to solvent vapour treatment were also examined. In general the behaviour was similar to that of unannealed samples but the scale of some of the changes and the rate of solvent uptake was modified.
Thermal Decomposition of energetic materials. 39. Fast thermolysis patterns of poly(methyl), poly(ethyl), and primary alkylammonium mononitrate salts
Authors: Russell T. P. , Brill T. B. 
Published: May 2005

AbstractFast thermolysis (> 100°C/s)/FTIR spectroscopy of alkylammonium mononitrate salts is described in terms of the gas products and the temperature and time correlations of their evolution. The salts studied are [(CH3)nNH4‐n]NO3, n = 1–3; [(CH3CH2)nNH4‐n]NO3, n = 1–4; and [CH3(CH2)nNH3]NO3, n = 0–3. In addition to the patterns among the small molecule thermolysis products, the tendency to form nitrosamines, amides, and alkylnitrates is presented. The release of HNO3 qualitatively correlates with the basicity of the parent amine. The tertiary ammonium nitrate salts did not release HNO3(g). The release of NH3(g) appears only to occur when the residue can stabilize itself. Otherwise, the parent alkylamine is released. The formation of nitrosamines upon fast thermolysis of di‐ and trialkylammonium nitrate salts makes these materials a potential health risk in formulations. There is no evidence that the nitrate salts convert to nitrosamines through a nitramine intermediate.
Thermal Decomposition of Energetic Materials. 40. Fast thermolysis patterns of Alkanediammonium dinitrate salts
Authors: Russell T. P. , Brill T. B. 
Published: May 2005

AbstractRapid‐scan FTIR/temperature profiling studies of the fast thermal decomposition of alkanediammonium dinitrate salts [H3N(CH2)nNH3](NO3)2, n = 1–4 and 6, are described. All of the salts liberate HNO3 and NH3 early in the first stage. When n = 1–3, small molecule products from redox reactions occur in the second stage of decomposition. When n = 4, 6, the second stage involves cycloclimination to form pyrrolidine (n = 4) and α‐ethlypyrrolidine (n = 6). The temperature of the onset of thermal decomposition is lower when n = 1 than when n is larger. Intra‐ and intermolecular hydrogen bonding are proposed to play a significant role in these decomposition patterns.
On the study of micromechanism governing Detonation Initiation of Nitramines and Nitrosamines
Authors: Zeman Svatopluk , Dimun Milan 
Published: May 2005

AbstractOn the basis of the published knowledge on micromechanism of detonation initiation, existence was predicted and indirectly proved of the direct relationship between activation energies of low‐temperature non‐autocatalyzed thermolysis of nitramines and nitrosamines, on the one hand, and their sensitivity to impact, on the other. The said relationship is presented as another piece of evidence of identity of the primary fragmentation in the detonation conversion of the above‐mentioned compounds with the primary fragmentation in their thermolysis. At the same time, there was taken notice of the higher thermal reactivity of nitrosamines as compared with their nitramine structural analogues.
The manufacture of high performance composite propellants and novel charges by Batch and Continuous Extrusion Processes
Authors: Cooke E. M. G. 
Published: May 2005

AbstractRecent developments in extrudable composite propellant technology enable higher energy/density formulations and novel charges to be successfully manufactured, which cannot be produced by castable composite technology processes. These also offer substantial capital, labour and time savings in certain production applications.New heavy duty processing machines have been developed recently, which have been used successfully for the safe and efficient manufacture of new high energy/fast burning rate composite propellants, using batch and continuous processes. These include injection flow forming techniques and die extrusion processes for filling rocket motors. A range of non‐energetic binder systems based on non‐curing plastic, curing HTPB and TPE binder systems have been successfully manufactured.
2,6‐Diarylmethylene‐thiazolo[3,2‐a]pyrimidine‐3,5,7‐triones as Stabilizers for Double‐Base Propellant
Authors: Soliman Adly A.‐W. , El‐Damaty A. A. , Awad W. H. E. 
Published: May 2005

Abstract2,6‐Diphenylmcthylene‐thiazolo‐pyrimidine‐trione, the o‐, m‐, and p‐nitrophenyl‐derivatives were prepared and incorporated as stabilizers in a double base smokeless powder. The prepared powders were subjected to some standard qualitative and quantitative stability tests. It was found that the 2,6 diphenyl trione (Ia) has a good stabilizing effect for double‐base propellants.
Temperature sensitivity of magnesium‐sodium nitrate propellants
Authors: Singh Harihar , Bhaskara Rao R. 
Published: May 2005

AbstractTemperature sensitivity of burning rate of magnesium‐sodium nitrate propellants has been determined at different mixture ratios in the temperature range between – 40°C and + 50°C. The results indicate that the temperature sensitivity is minimum at high magnesium loadings and increases as the proportion of magnesium in the mixture decreases. Thermal decomposition data indicate that the oxidation of magnesium with sodium nitrate in a propellant is governed by the condenscd phase heat release. This heat which is maximum at high fuel concentration is seen as causing prcssure independent, high burning rate with low temperature sensitivity. The reduction of magnesium content in the mixture increases the metal agglomeration on the surface of the propellant and causes for the decrease of condenscd phasc heat release and the reaction zone temperature. This causes for pressure dependent, low buring rate with high temperature sensitivity. The burning surface temperature data indicate that the change in the initial temperature of the propellant at low fuel concentration might be causing for the change in the degree of mctal agglomcration which lead to the increase of temperature sensitivity of burning rate. The photographs of the sliver surface obtained after static test at different initial temperature of the propellant support the suggested mechanism.
Friction sensitivity mechanism of Ammonium Perchlorate Composite Propellants
Authors: Bazaki H. , Kubota N. 
Published: May 2005

AbstractFriction sensitivity of ammonium perchlorate (AP) composite propellants has been studied experimentally by means of thermal analysis and micro‐thermocouple techniques. Several types of catalysts were mixed with AP in order to examine the effect of the reactivity on the sensitivity. The results of friction sensitivity test show that the samples are sensitized when the concentration of catalysis which are used for high burning rate propellants is increased. Metal contents within the catalysts tend to give some effects on the friction sensitivity. Based on the results of the temperature profile measurements in combustion waves, it is found that the friction sensitivity is correlated with the burning surface temperature of the propellants. The catalysts which accclerate the AP decomposition are responsible for the friction sensitivity but not for the fallhammer sensitivity.
Molecular structure of the ideal solid propellant binder
Authors: Stacer Ross G. , Husband D. Mark 
Published: May 2005

AbstractA study has been conducted to investigate the relationship between binder molecular structure and the mechanical/rheological properties of solid propellants. Beginning with the mechanical property requirements dictated by the motor grain operating conditions as well as rheological constraints imposed by available processing technology, the approach taken was to work backwards to obtain the ideal molecular structure of a solid propellant binder. Structural/processing requirements were determined from the demands of three typical rocket motor applications: space transfer, launch vehicle/ballistic missile, and tactical air‐to‐air. Three general formulation approaches to meet the demands of these applications were considered. These include traditional composite and nitrate ester plasticized formulation approaches, in addition to a hypothetical all‐binder propellant. For each of these three formulation approaches, a variety of polymer molecular characteristics were defined in terms of molecular weight, crosslink density, solubility parameter, chain stiffness, monomeric friction coefficient, volume fraction filler, and volume fraction plasticizer. Characterization data for ten polymeric binder systems are reported to show how their molecular architecture influences the resulting propellant properties.
Effects of liquid burn rate catalysts on Rheological Properties of High‐Energy Composite Propellants
Authors: Vuga Slobodan M. 
Published: May 2005

AbstractEffects of several liquid burning rate catalysts on rheological properties of composite rocket propellants on the basis of hydroxy‐terminated polybutadiene as a binder and ammonium perchlorate as an oxidizer have been examined. Theoretical explanation of the observed effects of liquid catalysts on certain rheological properties of the mentioned propellants are given. Laboratory procedures for synthesis of used catalysts are described. The results of physico‐chemical characterization of synthesized catalyst are also presented.
Method for the Determination of the Critical Diameter of High Velocity Detonation by conical geometry
Authors: Badners Hartmut , Leiber Carl‐Otto 
Published: May 2005

AbstractA critical diameter exists for both high velocity (HVD) and low velocity detonation (LVD). No relationship exists between these two diameters, however they are both dependent upon the temperature, confinement, contaminants, type of detonation and, most importantly, geometry. In cylindrical geometry, the critical diameter is determined by go/no go tests which are relatively expensive and time consuming. In this respect, there is a need for a method by which the critical diameter can be determined quickly and reliably.A relatively simple procedure which can also be performed in the field is proposed in this article where the critical diameter is determined in principle by a single test through the application of conical geometry. However, on account of “overdrive”, the values always fall below those obtained by cylindrical geometry. Metal plating is proposed as a method of indication. The results are then compared simultaneously by optical and electrical measurements. The temperature dependence of the critical diameter of the HVD of pure nitromethane was also demonstrated by conical geometry and was compared to the values of cylindrical geometry.The method was originally proposed as a joint US/German effort between Dr. Mallory of NSWC, China Lake, and Dr. Leiber of BICT. Since Dr. Mallory has recently passed away, the question is therefore open as to whether or not this test can be approved internationally.
Thermal Behaviour of HMX/RDX Mixtures
Authors: Quintana José R. , Ciller Juan A. , Serna Felipe J. 
Published: May 2005

AbstractThermal behaviour of HMS/RDX mixtures is studied by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). It has been found that the temperature of polymorphic transformation of HMX shows an increase due to the presence of RDX. The enthalpies of the enothermic transformations depend on the composition of the mixture, and up to 30% RDX there is a linear relationship. The formation of an eutectic with a composition of 30/70 (HMX/RDX) is postulated to explain the melting processes.
Probability Estimation for the Self‐Ignition of the Gun Powder
Authors: Čolaković Miloš 
Published: May 2005

AbstractA theoretical approach to the possibility of estimation of the heat development rate and heat accumulation rate until self‐ignition, is presented. Gun powder was thermally degradated until self‐ignition occures at several different temperatures in the vessels of different sizes. A microcalorimeter of the specific type was constructed for the detection of the thermal effects of the chemical degradation in the vessels of different sizes. T was measured for gun powder and for inert samples. Kinetics was calculated, and the obtained parameters were used for determination of the critical conditions of self‐ignition. In addition, diagrams are given for the time to self‐ignition determination even in the cases when critical conditions have not yet been achieved.