bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Blast Wave on Hard Structure
Authors: Liehmann W. 
Published: May 2005

AbstractIn this paper the pressure‐time histories of bursting gas vessels in closed rooms are investigated and discussed on the basis of TNT‐nomograms.Experimental data of TNT‐charges from 0.1 kg to 1.5 kg were measured on various points in a closed room. To describe the results a simplified linear wave model was applied and a good agreement with the experimental data observed.Similar experiments with bursting gas storage vessel were performed and compared with the TNT‐results. A TNT‐blast equivalent was defined and established. In addition a computer code was created. By use of the input data, which are energy content of the vessel, geometry of the room and other physical parameters, pressure‐time histories are calculated. These can be directly used for predicting the loading factors of hard structures.
Sensitivity of nitromethane for low velocity detonation
Authors: Ijsselstein R. R. 
Published: May 2005

AbstractRecently the occurrence of a low velocity detonation (LVD) in nitromethane has been demonstrated. In the present study this phenomenon has been further investigated by mapping the shock loading regime in which a stable LVD can develop. A confinement geometry has been chosen that earlier appeared to be able to sustain the LVD. A calibrated shock donor system has been used, so that loading shock strengths were known. The critical shock strengths for the occurrence of both high and low velocity detonation could thus be determined. Including LVDs, nitromethane appears to have a sensitivity comparable to that of relatively sensitive high explosives. The results also indicate that the geometries of some standard shock sensitivity tests are not fully adequate to detect an LVD in nitromethane.
2,4,6‐Triphenyl‐ thiazolo[3,2‐a]‐s‐Triazine as a Stabilizer for single base propellant
Authors: Soliman Adly A.‐W. 
Published: May 2005

Abstract2,4,6‐Triphenyl‐2,3,4,7‐tetrahydro‐thiazolo[3,2‐a]‐s‐triazine is used as a stabilizer for single base propellant and gave good results with the stability tests. Comparing the results of the stability and storage tests at 80°C, 90°C and 100°C with the results of the same tests after using diphenylamine instead of the thiazolo compound gave the same results without difference between the two stabilizers.
Crack Initiation in Perforated Propellants under high strain rate impact conditions
Authors: Fong C. W. 
Published: May 2005

AbstractThe fracture behaviour of gun propellant grains during impact has been measured on a modified Hopkinson Bar which uses a projectile as the input bar. Evidence for the detection of initial minor crack formation in seven‐perforated cylindrical specimens of single base, double base and triple base propellant is presented. Under compressive load (pressurization rates of 100 GPa/s‐200 GPa/s), minor crack formation does not immediately result in large scale crack propagation or fragmentation of the specimens. The single base and triple base propellant are equally more resistant to crack initiation than the double base propellant when tested in either the end‐on or side‐on modes. Implications for munition survivability are discussed in terms of mechanical frictional effects caused during compressive loading of cracked propellant or compressive heating in propellant cracks during the ballistic cycle.
The Compressional Heating Hazard in the Pressing of Propellant Doughs
Authors: Hawkins S. J. , Privett G. 
Published: May 2005

AbstractThe compressional heating hazard encountered during propellant dough extrusion, is discussed. A mathematical model describing a “worst case” situation is derived, and solved using a mini computer. The results indicate that pressurization regimes commonly used may be unnecessarily slow for small press sizes.
Determination of Gaseous and Solid Decomposition Products of Nitroguanidine
Authors: Volk F. 
Published: May 2005

AbstractIn spite of many publications dealing with the thermal decomposition of the cyclic nitramines RDX and HMX, the decomposition behavior of nitroguanidine (nigu), especially in the low temperature range, has not been investigated fundamentally in the past. Because nitroguanidine is an important explosive component for triple base propellants, a better understanding of the thermal decomposition at low temperatures is of interest.For example, aging studies of triple base propellants exhibited a different decomposition behavior from single and double base propellants. Therefore nigu is supposed to influence the safe life time of propellants containing nitric acid esters.The investigations of the decomposition of nigu published in the past, have been performed at temperatures between 190°C and 240°C. The aim of this work was to study the decomposition behavior of nigu at temperatures as low as possible.In this connection, temperatures between 110°C and 240°C have been used. In this temperature range, nitroguanidines with different grain sizes have been investigated by measuring the weight loss and analyzing the decomposition gases by mass spectrometry. Also solid residues, like ammeline and melamine, remaining after the degradation tests were analyzed quantitatively by using high performance liquid chromatography. The formation of melamine and ammeline was found to depend strongly on the amount of the weight loss of nigu. The better stability behavior of triple base propellants is possibly due to the formation of NH3 which is being formed in the decomposition process of nigu. Ammonia reacts with nitric oxides and behaves therefore similar as a stabilizer.
The effects of gas explosions in free and partially confined fuel/air mixtures
Authors: Pföurtner H. 
Published: May 2005

AbstractTo obtain a further insight into the complex flame acceleration process of deflagrating fuel/air mixtures experimental investigations were carried out in free and partially confined homogeneous clouds with hydrogen as a fuel. The results of the experiments in an unconfined hemispherical configuration show a distinct dependence of the flame velocity on the cloud size which does not exceed, however, an upper limiting value. The experiments under partially confined conditions without additional turbulence indicate that the flame velocity and consequently the pressure field is governed by the hemispherical flame front initially formed; i.e. the flame velocity is not affected by the partial confinement. To increase the turbulence effects further experiments were carried out with a fan and with jet ignition. In the case of fan induced turbulence the flame velocity was strongly influenced by the fan speed. At a certain fan capacity the transition of a deflagration into a detonation was observed. With jet ignition produced by venting an explosion chamber into the partially confined cloud the transition occured even with hydrogen concentrations in air as low as 22 vol%. The results which are discussed on the basis of turbulence models show that high damaging overpressures or the transition from a deflagration into a detonation are only generated by strong turbulences as a consequence of flow and/or obstacles.
Rheological Characterization of Fuming Nitric Acid Gel
Authors: Gupta B. L. , Varma M. , Goel S. B. 
Published: May 2005

AbstractRheological characterization of fuming nitric acid gel has been attempted in low and high shear rate ranges using Brookfield and capillary viscometers respectively. The gel has been found to behave as a pseudoplastic thixotrope.
Use of kinetic DTA and TG methods for compatibility tests on 2,4,6‐‐trinitrotoluene
Authors: Hemmilä M. , Nieminen I. , Kariniemi A. , Valkonen J. 
Published: May 2005

AbstractWe have investigated the suitability of thermoanalytical methods for compatibility tests on explosives and contact materials. DTA and TG curves of various materials were evaluated using two DTA and four TG methods and one DSC method. TNT was used as model substance. The contact materials were paraffin, polyethylene, an epoxy resin paint and an epoxy glue. In earlier tests the first two were found compatible and the latter two incompatible with TNT. None of the methods provides an absolute value for the activation energy. However, in compatibility tests only the relative change in the activation energy is of interest and, for this, three of the methods proved informative.
The Cutting of Steel Tubes by Explosives Techniques. Cutting performance and effects on environment
Authors: Schumann St. , Freund H. U. , Geiger W. 
Published: May 2005

AbstractIn the light of special applications, trials were carried out on the separation of steel tubes using commercially obtainable explosive cutting charges in an annular configuration in order to find out their cutting performance and the effects on the environment incurred during separation. Tubes made of St37 steel having a diameter of 220 mm and a wall thickness of 10 mm as well as tubes consisting of hightensile 15 Mo 3 steel with a diameter of 273 mm and a wall thickness of 12.5 mm were used for this purpose. It was possible to cut the tubes accurately and neatly with the charges used. However, the projectiles formed during the detonation process are not compact, for which reason the cutting performance of the commercial charges used is not optimal. There is here a considerable potential for improvement. Measurements of the environmental effects conducted during the trials (fragmentation, blast wave, projectile impact on tube line) show that the incidental effects of explosive tube cutting are controllable.
Sensitivity and Evaluation of Explosive Substances
Authors: Fukuyama I. , Ogawa T. , Miyake A. 
Published: May 2005

AbstractExplosion sensitivity involves many complex factors. A theory for evaluating and a method for testing have to be established. We have proposed an explosion sensitivity theory for explosive substances and have also tested the evaluating method. The results of our research reveal a satisfactory mutual relation between both theoretical and experimental values.
Viscosity Prediction of Composite Solid Propellant Slurry
Authors: Ke‐Xi Yang , Ze‐Ming Tao , Guo‐Juan Wang 
Published: May 2005

AbstractThe viscosity of composite solid propellant slurry is an important parameter in charging technical performance of solid rocket motors. It is affected not only by the liquid phase ingredients of propellants, but also by the size, content, shape and surface properties of solid fillers in propellants. This paper will present a prediction formula of viscosity of composite solid propellant and will also give a method for calculating the maximum packing volume fraction of solid in the formula. One can predict the viscosity of propellant slurry with the formula if the composition of the propellant is known.
Thermal Decomposition of Energetic Materials XVIII. Bis (cyanomethyl)nitramine and Bis(cyanoethyl)nitramine
Authors: Oyumi Y. , Rheingold A. L. , Brill T. B. 
Published: May 2005

AbstractThe crystal structures of two potentially useful cyanonitramines are reported. Bis(cyanomethyl)nitramine (BCMN), (NCCH2)2NNO2: monoclinic, C2, a = 10.247(1), b = 7.771(1), c = 12.230(2) [Å], β = 107.45 (2)°, Z = 6, Dcalc = 1.502 g.cm−3, RF = 2.8%, RwF = 3.1%. A syn (C2) and anti (Cs) isomers of BCMN crystallize together in a 2:1 ratio in the unit cell. Bis(cyanoethyl)nitramine (BCEN), (NCCH2CH2)NNO2: monoclinic, P21/c, a = 7.512(2), b = 10.840(3), c = 10.181(3) [Å], β = 97.39(2)°, Z = 4, Dcale = 1.357 g.cm−3, RF = 4.6%, RwF = 4.7%. Only one conformation of the BCEN molecule having no symmetry is present in the unit cell. The IR spectrum shows that BCEN forms an amorphous phase when the melt is cooled or when an acetone or acetonitrile solution is rapidly evaporated. The amorphous phase slowly crystallizes at room temperature. High‐rate thermolysis of BCMN liberates NO2 as the predominant initial product. This difference is qualitatively predictable on the basis of the variation in the N‐N bond distance in these two compounds.
Ballistic Modification of Composite Modified Double‐Base Propellants containing ammonium perchlorate
Authors: Raman K. V. , Singh Haridwar , Rao K. R. K. 
Published: May 2005

AbstractThe effect of certain lead and copper salts of organic acids and metallic oxides was studied on the burning rates and heat of explosion of CMDB propellants containing AP. Among lead and copper salts, basic lead salicylate gave increased burning rates, whereas lead methylene disalicylate and basic copper salicylate did not produce catalytic effect. In the case of metallic oxides, ferric oxide and cobalt oxide gave better catalytic activity than copper and chromium oxides. On crosslinking of nitrocellulose with an isocyanate, catalytic activity of ballistic modifiers was reduced. Burning rates obtained in a rocket motor (2‐kg propellant) were higher by about 15%‐20% than by strand burner (Crawford Bomb) method.
Combustion Process of Mg/TF Pyrotechnics
Authors: Kubota N. , Serizawa C. 
Published: May 2005

AbstractThe combustion process of pyrotechnics was studied in order to obtain informations of the rate control parameters of burning rate. The pyrotechnics tested was made of Mg (magnesium) and TF (polyfluoroethylene). The burning rate measurements revealed that the burning rate of the Mg/TF propellants (pellet in shape) increases with increasing the weight fraction (ξ) of Mg in the range of ξ > 0.33. Though the adiabatic flame temperature is the maximum at ξ = 0.33, the burning rate increases with decreasing the flame temperature. The total burning surface area of the Mg particles mixed with in the unit mass of propellant plays an important role on the oxidation process in the gas phase just above the propellant burning surface. The heat flux feedback from the gas phase to the propellant burning surface increases with increasing ξ. Therefore, the burning rate increases as ξ increases.
Determination of Derivatives of Diphenylamine in Australian Gun Propellants by high performance liquid chromatography
Authors: Curtis N. J. , Rogasch P. E. 
Published: May 2005

AbstractA new high performance liquid chromatography (HPLC) method has been developed for the quantitative analysis of diphenylamine and its N‐nitroso‐ and C‐nitro derivatives found in single‐base gun propellants. Of the potential derivatives, only 2‐ and 4‐nitrodiphenylamine, 2,2′‐, 2,4′‐ and 4,4′‐dinitrodiphenylamine, 2,2′4‐ and 2,4,4′‐trinitrodiphenylamine. 2,2′4′4′‐tetranitrodiphenylamine, N‐nitrosodiphenylamine and 4‐nitro‐N‐nitrosodiphenylamine were found in major amounts. Minor derivatives noted were: 2,4‐dinitrodiphenylamine, 2‐nitro‐N‐nitrosodiphenylamine, 2,4′‐ and 4,4′‐dinitro‐N‐nitrosodiphenylamine. Other derivatives were looked for but not found. This HPLC method can be used to quantify all the major derivatives in a single chromatogram and importantly, can be used even in the presence of propellant additives dinitrotoluene, di(ethylhexyl) phthalate and dibutyl phthalate. This procedure provides the most effective analysis of stabilizer in single‐base propellants yet published. We have used this method to study the derivatisation of diphenylamine as a function of aging in Australian single‐base gun propellants.
Temperature sensitivity of Burning Rate of Ammonium Perchlorate Propellants
Authors: Kubota N. , Miyazaki S. 
Published: May 2005

AbstractThe temperature sensitivity of burning rate of ammonium perchlorate (AP) composite propellants was studied as a function of AP particle size and a burning rate catalyst. A simplified temperature sensitivity model was presented in order to discriminate the effect of the gas phase and solid phase reactions on the initial propellant temperature (T0). The temperature sensitivity was decreased by the addition of small sized AP particles and/or 2,2‐bis(ethylferrocenyl)propane (BEFP). This is caused by the insensitive burning surface temperature to T0. Thus, the gas phase reaction rate becomes little dependent on T0, and the temperature sensitivity decreases.
The properties of 1,3,3,5,7,7‐hexanitro‐1,5‐diazacyclooctane (HCO) and its application in propellants
Authors: Li‐Hua Xu , Ming‐xuan Wang , En‐pu Wang , Hui‐min Tan , Bo‐ren Chen 
Published: May 2005

AbstractThe properties of HCO and its application as a monopropellant were described. In comparison with HMX, it is also a high energetic explosive with high thermostability and can be used as an oxidizer in solid rocket propellants.Theoretical specific impulse of HCO‐double base propellant systems were calculated and the burning rates and thermostability of propellant were experimentally determined. Propellants were prepared with a spray‐casting process. As an oxidizer in solid rocket propellant, HCO shows better characteristics under certain aspects compared with HMX.
Melt Phase Decomposition of RDX and Two Nitrosamine Derivatives
Authors: Oyumi Y. 
Published: May 2005

AbstractThermal decomposition of hexahydro‐1,3,5‐trinitroso‐s‐triazine (TRDX), C3H6N3(NO)3, and hexahydro‐1,3‐dinitro‐5‐nitroso‐s‐triazine (MRDX), C3H6N3(NO2)2(NO), was studied by DTA and TGA in argon atmosphere, which was showing overall first‐order kinetics. The results are compared with those for RDX in order to determine the effect of replacing > NNO2 group with > NNO. The decomposition of the admixture of RDX/TRDX (50/50 by weight) was also tested. The kinetic parameters calculated are: for RDX, ln k = 43.1–47,900/RT, for MRDX ln k = 34.3–37,200/RT, for TRDX ln k = 29. 4–30,500/RT, while for the RDX/TRDX admixture, ln k = 37.0–39,700/RT, where k is in s−1. The melt phase decomposition products of RDX, MRDX, and TRDX condensed on a NaCl plate which was placed 2 cm above the sample cell were almost exactly the same in IR measurements. RDX is soluble in liquefied TRDX and the decomposition of RDX is accelerated by its liquefaction.
Selection of an igniter system for magnesium‐based solid fuel rich propellant
Authors: Singh Harihar , Somayajulu M. R. , Bhaskar Rao R. 
Published: May 2005

AbstractSuitability of a number of metal based igniter compositions have been studied for magnesium based fuel rich propellant. Igniter compositions have been tested in closed vessel for evaluation of ignition pressure output and impetus. Heat energy values were determined calorimetrically in a closed bomb. Vented vessel study was carried out in a test motor for assessing relative behaviour and to select a suitable composition. Compositions containing magnesium powder and potassium nitrate were found to give satisfactory ignition to the propellant.
Optimization of Spark and ESD Propellant Sensitivity Tests. A review
Authors: Mellor M. , Stoops David R. , Rudy Tom P. , Hermsen Robert W. 
Published: May 2005

AbstractAll cured propellants can pass small‐scale spark sensitivity tests, yet some, generally involving larger propellant samples, are electrostatic discharge (ESD) sensitive. These tests fail to rank propellants because the test methods themselves are not optimized and frequently use instrumentation which does not indicate the energy transferred to the sample.For spark ignition of premixed combustible gases or fuel sprays in air, minimum energies are measured and considered thermochemical properties for a given fuel/air ratio, initial temperature and pressure, and for a spray, a given droplet size distribution. Obtaining such data requires monitoring the total energy discharged across the gap during the spark and parametric studies where gap length and spark duration are varied systematically to establish the true minimum (essential to hazard/risk analysis). Electrode geometry and tip design, as well as electrode material, are other important considerations.Present spark and ESD sensitivity tests used for solid propellants are reviewed in the context of methods more likely to provide meaningful initiation thresholds.
Spectrophotometric Determination of Lead in some propellants
Authors: Zaki M. Tarek M. , Bassioni H. H. , Sedra M. N. R. , Attiya S. M. 
Published: May 2005

AbstractA new sensitive method has been proposed for the determination of lead in some single‐ and double‐base propellants. The method is based on the color reaction of lead(II) with hematoxylin in presence of the cationic surfactant cetyltrimethylammonium bromide. At pH 8.0, the formed ternary system possesses an absorption maximum at 605 nm with a molar absorptivity of 5.5 × 104 l · mol−1 · cm−1. The system adheres to Beer's law up to 1.78 ppm of lead, and the sensitivity index is 0.0039 μg · cm 2. The susceptibility of interference of common ions is studied and some masking agent solutions are recommended to improve the selectivity of the method. The proposed method shows good agreement with the results obtained by atomic absorption spectrometry. An average recovery of 99.3% with a standard deviation not exceeding 1.7% is observed.
Synthesis of novel energetic compounds. 8. Electrosynthesis of azidodinitromethyl compounds
Authors: Weber James F. , Frankel Milton B. 
Published: May 2005

AbstractAzidodinitromethyl compounds represent a new highly energetic class of propellant ingredients. Preparation of these materials was accomplished by means of electroxidative coupling of azide ions to dinitromethyl carbanions. Thus, anodic coupling of sodium azide with ethyl 4,4‐dinitrobutyrate produced ethyl 4‐azido‐4,4‐dinitrobutyrate. Similarly, 4‐azido‐4,4‐dinitrobutyl acetate was prepared from 4,4‐dinitrobutyl acetate and converted by way of the corresponding alcohol to the nitrate ester, 4‐azido‐4,4‐dinitrobutyl nitrate.
Linking experimental and theoretical results on the Deflagration to Detonation Transition
Authors: Verbeek Ries , van der Steen Albert 
Published: May 2005

AbstractThe results of a DDT tube test are compared with the outcome of a numerical model. The interaction between the two research methods leads to a better understanding of the DDT phenomenon than each method separately. For the situation tested the way of ignition and the particle diameter appeared to be important factors for the DDT process.
Performance of High Explosives in Underwater Applications. Part 1: CHNO explosives
Authors: Strømsøe E. , Eriksen S. W. 
Published: May 2005

AbstractThe change in postdetonation free energy, rather than the often used change in detonation enthalpy, is suggested as a measure of the underwater performance of high explosives. Results of a correlation analysis of data from 11 explosives are presented. It is suggested that the detonation pressure is also a significant factor for the energy available for mechanical work, but this can not be verified by the present data. However, in the partition of energy between shock wave and bubble the detonation pressure is the dominant factor.
Performance of high explosives in underwater applications. Part 2: Aluminized explosives
Authors: StrøMsøE E. , Eriksen S. W. 
Published: May 2005

AbstractThe change in postdetonation free energy has been used for assessment of the sum of shock and bubble energies of aluminized explosives in underwater applications. As has been suggested for CHNO explosives the detonation pressure also in this case seems to be a significant factor. For compositions with a high Al content it is probable that additional energy becomes available from reaction of Al with water in the surrounding medium.