bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Hypergolicity of Several Liquid Fuels with fuming nitric acids as oxidizers
Authors: Durgapal U. C. , Dutta P. K. , Pant G. C. , Ingalgaonkar M. B. , Oka V. Y. , Umap B. B. 
Published: May 2005

AbstractHypergolic or self ignition delays of unsymmetrical dimethylhydrazine (UDMH) and several amine fuels, mixed with three fuming nitric acid oxidizers, have been determined, at room temperature, in a highly sensitive “Cup Test” apparatus. Ignition delay (ID) variations have been studied with respect to the chemical structure of fuel, oxidizer composition, and oxidizer‐to‐fuel (O/F) ratio. Probable preignition reactions and structure‐hypergolicity correlations have been suggested.Some non‐hypergolic hydrocarbons and petroleum fractions have been hypergolized by addition of UDMH, and ID variations have been studied with respect to UDMH‐content in fuel and catalytic additives (ammonium metavanadate, ammonium dichromate, and cuprous oxide) in the red fuming nitric acid oxidizer (RFNA). Increment in UDMH‐content improves the hypergolicity of fuels towards RFNA. For example, kerosene + UDMH 60:40 blend ignites with RFNA with a remarkably low ID of 6 ms. However, the catalytic effect of the additive in RFNA varies widely with the fuel‐blend composition.
A Modification of the Mott Formula for prediction of the fragment size distribution
Authors: Strømsøe E. , Ingebrigtsen K. O. 
Published: May 2005

AbstractA modification of the Mot fragmentation formula, accounting for a maximum fragment size, is suggested. Twelve experimental data sets are used to test the goodness of fit of the original and the modified formula. Generally, the modified formula is found to give a better representation of the experimental data, and particularly, the overestimation of the number of very large fragments is avoided.
Effect of High Dynamic Pressure on the Structure of Solids
Authors: Batsanov S. S. 
Published: May 2005

AbstractThe influence of shock waves on crystal macrostructure and its physical and technological consequences are discussed. The size of crystal particles grain corresponding to the transition of solid into amorphous state is estimated. The magnitudes of microstrains in crystals during their grinding are calculated. It is shown that under shock‐wave treatment the grain size and microstrain are usually about 10 times differed from the values in amorphous substances. The possibility of amorphization during chemical interaction under shock compression is shown. Phase transformations with change of stoichiometry under shock waves prove a perspective synthetic method.
Kinetic mechanism on Thermal Degradation of a Nitrate Ester Propellant
Authors: Kimura J. 
Published: May 2005

AbstractThe thermal degradation of a double‐base propellant has been studied to elucidate the rate‐determining steps and the kinetic mechanism in a wide range of temperatures (60°C–200°C) by using modified Taliani test, thermogravimetry (TG), and temperature‐varied Abel (TVA) test. The results indicate that the degradation process consists of two major reactions, homolysis and autocatalysis, depending on temperature and total pressure due to evolved gases. The activation energy for the homolysis was obtained to be 35–37 kcal/mol from Taliani and TVA tests, which fall in the range of the bond dissociation energy of the weakest bonds RO–NO2. The activation energy for the autocatalysis was determined to be 46–49 kcal/mol from Taliani and TG methods. Those values observed for the two key reactions are totally opposite to reported values in the earlier literature. The temperature dependence of the reaction rates obtained in this study implies that the homolysis is the rate‐determining step in the lower temperature range, the autocatalysis in the higher temperature range.
Flyer Plate Motion by Thin Sheet of Explosive
Authors: Yadav H. S. 
Published: May 2005

AbstractAcceleration of a metal plate by explosive energy at low value of charge to metal mass ratio has been studied by employing a new theoretical model based on uniform pressure and density of detonation products behind the flyer plate. Theoretical velocities of flyer plates have been compared with those measured by radiographic technique and found in good agreement. Comparing the relations for plate velocity, obtained from the present model and earlier Gurney model at low C/M values, an analytical expression for Gurney energy has been obtained in terms of detonation velocity of the explosive and adiabatic exponent of the detonation products.
Critical energy criterion for the shock initiation of explosives by projectile impact
Authors: James H. R. 
Published: May 2005

AbstractThe critical energy (Ec) criterion developed by Walker and Wasley for predicting the response of bare, heterogeneous explosives to flying‐plate impact, is modified for application to flat‐nosed rods and spherical projectiles. This modification redefines the shock duration term used in calculating Ec and implies that a minimum volume of explosive at a given shock energy is needed before initiation occurs. The modification also changes the L/D ratio of the projectile at which plate behaviour changes to rod behaviour from the currently accepted value of approximately 1/4 to 1/12. Comparisons between the modified criterion and published experimental data show that the same value of Ec can now be obtained from both flying‐plate and more complex projectile impacts into the same explosive.
Interaction of a Metallic Jet with a Moving Target
Authors: Yadav H. S. 
Published: May 2005

AbstractStudy of interaction of a high velocity jet with a moving target has been carried out on the basis of simplifying assumptions of constant velocity of the jet and the target plate. The theoretical model meets the boundary conditions of the problem and predicts satisfactorily the main features of the phenomenon and the trend in variation of parameters like depth of penetration, surface cut and total distance travelled by target during the time of interaction of complete length of the jet. Unlike jet penetration in a stationary target, the penetration in a target, accelerated by thin layer of explosive, has been found independent of density of the target. The penetration, however, has been found strongly dependent on the angle of impact and the ratio of jet and target velocities.
Analysis of the shaped charge jet induced reaction of high explosives
Authors: Held M. 
Published: May 2005

AbstractA new optical recording technique for analyzing the initiation of high explosives under the impact of a shaped charge jet is described. This method permits determining, in “one single” test, the type of reaction – i.c. no reaction or reaction or detonation ‐ and the parameters build‐up distance Δs run‐up time Δt, initiation time ti and initiation distance Zi in the acceptor charge by observation of the acceptor charge side‐on and, via a mirror, also end‐on with simultaneous streak and framing recording.
The effect of high spin on the performance of tracer compositions
Authors: Briére Paul 
Published: May 2005

AbstractA unique tracer evaluation facility has been put into operation at the Defence Research Establishment, Valcartier (DREV), in order to characterize tracer compositions loaded in 5.56 mm envelopes. The effect of rotational speeds up to 300,000 rpm on the performances of two tracer compositions and the standard Belgian L‐110 tracer was studied in this facility. The trace duration decreased substantially with any increase in spin speed. The luminous output was observed generally to be weak at low rotational speeds and to increase with any rise in spin over 150 krpm. The formation of a convex surface of combustion in the composition under spin and the degree of obstruction of the projectile mouth by the combustion residues are postulated to explain such behaviours.
Development of a Pyrolysis‐Gas Chromatographic Method for characterization of plastic‐bonded explosives
Authors: Druet Linda M. , Degenhardt Carla A. E. M. 
Published: May 2005

AbstractAs part of a program to develop chemical tests which can be used to complement existing tests for mechanical properties, propellant ballistic performance, and explosive sensitivity, a detailed experimental procedure is presented for analysis of plastic‐bonded explosives (PBX's) by the coupled method of pyrolysis‐gas chromatography (PyGC). The method involves grinding the cooled PBX, pressing a controlled quantity on a pyrolysis wire, performing Curic‐Point pyrolysis, and detecting the products after separation by gas chromatography. PyGC results are presented to show the capability of the method to differentiate aged and unaged samples of PBX's and to differentiate stabilized and unstabilized PBX's based on RDX. Also included are results from several series of reproductibility studies, which suggest that the method may require only minor modifications before it can be implemented for regular screening of these complex formulations.
Initiation and detonation of RDX and HMX HTPB‐Based Plastic‐Bonded Explosives
Authors: van der Steen Albert , Verbeek Ries 
Published: May 2005

AbstractPlastic‐bonded explosives (PBXes) with different cross‐link densities and based on explosives with different particle size distributions have been compared for their initiation and detonation properties. The investigations showed that HMX‐based formulations become less sensitive at lower cross‐link densities. The shock sensitivity of two RDX‐based formulations differed considerably. This could have been caused by the particle size distribution of the RDX, but it could also be due to the fact that the explosives were obtained from different sources.
Modified Cycle‐Cast of TNT Based Explosives
Authors: Lee Yng‐Long , Wu Bor‐Horng , Lin Wei‐Ming , Sung Po‐Hou , Lin Kuei 
Published: May 2005

AbstractThe gain sizes of TNT‐HNS cast were examined. The results show higher melt temperature of TNT‐HNS mixture produces larger crystals. Based on two assumptions, equilibrium exists among TNT, HNS and nucleant complex 2TNT:HNS, and the dissociation of the nucleant is of endorthermic nature, an one‐stage cycle‐cast process is proposed. This process also yields fine, randomly oriented grain structure as Bofors' cycle‐cast process has claimed.
Thermal Decomposition of Energetic Materials 41. Fast thermolysis of cyclic and acyclic ethanediammonium dinitrate salts and their oxonium nitrate double salts, and the crystal structure of piperazinium dinitrate
Authors: Russell T. P. , Brill T. B. , Rheingold A. L. , Haggerty B. S. 
Published: May 2005

AbstractFast thermolysis/FTIR spectroscopy of [H3NCH2CH2NH3]‐(NO3)2 (EDD), [H2N(CH2CH2)2NH2](NO3)2 (PIPDN), and [HN(CH2CH2)3NH](NO3)2(DABCOD) and new oxonium nitrate (H3O+NO−3) double salts of PIPDN and DABCOD is described. EDD initially yields HNO3 and then small molecule decomposition products from redox reactions when heated at ≥ 100°C (dcc.). PIPDN initially yields HNO3, but then generates a significant amount of N,N′‐dinitrosopiperazine along with small molecule fragments. DABCOD produces no HNO3(g), but instead gives CH2O, N,N′‐dinitrosopiperazine and small molecule products. These patterns are entirely consistent with the behavior observed for primary, secondary and teritary ammonium mononitrate salts in our previous work. The presence of nitrosamines strongly increases the health hazard of the matcrials upon heating. No nitramines were detected as thermolysis products. Thermolysis of the oxonium nitrate double salts liberates HNO3 and H2O at a relatively low temperature (≥ 60 °C). Above this temperature, the thenmolysis proceeds in the same way as that of pure PIPDN and DABCOD. The crystal structure of PIPDN is described.
Non‐Destructive Reliability Analysis of a Bridgewire Fuze Head
Authors: Leeuw Matthijs W. 
Published: May 2005

AbstractIn this paper a novel method to determine the reliability of a bridgewire fuze head is proposed. It is assumed that a bridgewire will respond positively to a current pulse if the bridgewire temperature exceeds a critical value as a result of the pulse. To calculate the bridgewire temperature the distributions of four thermal parameters that characterize the electrothermal response of a bridgewire fuze head are used. Preliminary results indicate that this novel approach is in agreement with classical methods. Furthermore, one needs to test a limited amount of items and only a fraction of the tested items is destroyed.
Initiation of some energetic materials by microwave heating
Authors: Hasue Kazuo , Tanabe Masami , Watanabe Nobutune , Nakahara Shoji , Okada Fumiaki , Iwama Akira 
Published: May 2005

AbstractMicrowave heating of ammonium nitrate (AN), tetryl, PETN, RDX, HMX, TNT, emulsion explosive, Composition C‐4, and ammonium perchlorate (AP) was carried out at the frequency of 2450 + 50 MHz. The energetic materials were confined in sodalime glass tubes with teflon and silicon rubber plugs. The order of increasing initiation delay time was AN, tetryl, PETN, RDX, HMX, and TNT. Also, the order of the initiation energy of energetic materials was the same when the anode currents of microwave power source were 1.1 A and 0.8 A. The initiation processes of energetic materials were recorded on videotapes which showed that the energetic materials gencrally melted before initiation. The temperatures of energctic matcrials were measured by K‐type (chromel‐alumel) thermocouples and an infrared thermometer. The temperature of each energetic material started to rise rapidly when the temperature neared the meiting point. Initiation occured near the ignition temperature with a delay varying from 6 to 109 seconds.
Thermal Decomposition of Energetic Materials. 36. Fast thermolysis of overoxidized nitro– and halonitro nitramines
Authors: Subramanian R. , Brill T. B. 
Published: May 2005

AbstractTemperature profiling/FTIR is described for the fast thermolysis of four C‐NO2‐containing nitramines whose oxygen content exceeds the balance to CO2. The compounds are [(NO2)3CCH2N(NO2)CH2‐]2 (ONDO), [(NO2)3CCH2]2N(NO2) (BTNEN), [Cl(NO2)2CCH2]2N(NO2) (CDNEN), and [F(NO2)2CCH2]2N(NO2) (FDNEN). By themselves, these compounds are found not to be especially exothermic during the rapid decomposition off‐gasing phase probably because of their overoxidized nature. The halogen atoms appear as ClNO and FNO in the gas decomposition products.
Studies of the Sensitivity of Explosive Dusts to ignition by electric sparks
Authors: Thomas G. O. , Oakley G. L. 
Published: May 2005

AbstractResults are presented of an experimental investigation of the sensitivity of clouds of high explosive dusts in air to ignition by electrostatic sparks. The sensitivities are derived from determinations of the frequency of ignition of dispersed clouds of dusts when subject to electric sparks of varying energies. In addition to dust composition the parameters considered include the density of the cloud and the particle size distribution. The influence of the discharge circuit characteristics on the ignitability of dust clouds is also investigated. The majority of the tests were conducted with quasi‐static dust clouds, but results are also presented from tests with moving dust clouds. These clearly indicate that the energy required for ignition increases with the velocity of the carrier gas.
The Dependence of Friction Sensitivity of Primary Explosives upon rubbing surface roughness
Authors: Le Roux Jurie J. J. P. A. 
Published: May 2005

AbstractA large variation in surface roughness of the procclain plates, in use on the BAM friction tester (Julius Peters), was observed and confirmed by surface texture measurement. The relationship between the friction sensitivity of primary explosives and the rubbing surface roughness was investigated by using different emery‐paper grades.The replacement of porcelain friction plates by an emery‐paper test‐piece is suggested. Apart from improved reliability of results, this modification to the existing technique greatly reduces the associated safety risk, costs and lesting time.
Fragment Mass Distribution of HE Projectiles
Authors: Held Manfred 
Published: May 2005

AbstractThe description of the fragmcnt mass distribution according to Held is in cxcellent agreement with the experimental data. This is true in particular when the total mass, Mo. used in describing the distribution, is slightly modified in that some of the hcavicst fragments are neglected. Because in the case of a shell they do not necessarily follow the distribution law.
The effects of thermal gradients on Performance of End‐Burning Rocket Motors
Authors: Irvine Robert D. 
Published: May 2005

AbstractThe effect of a non‐uniform temperature distribution on the thrust‐time performance of an end‐burning solid propellant rocket motor charge is examined. It is shown that non‐planar surfaces develop. For some classes of temperature distribution, the effect of these non‐planar surfaces os always between the limits of the thrust predicted at the maximum and minimum temperatures. The class of temperature distributions that meet this criterion is determined and a simple inequality is derived to test any actual distribution. An expression for the departure from specification is given for distributions outside this class. These results partially justify the proof of ballistic design by testing motors of uniform temperature at upper and lower limits, when service motors may be exposed to uneven heating. The validity of such testing in actual cases can be determined.
Explosion of Explosives in Subsurface Magazines and its numerical analysis
Authors: Adachi Tetsuhiko , Munemasa Kunihiko , Hasue Kazuo , Nakahara Shohji 
Published: May 2005

AbstractThe subsurface magazine is a new type of magazine in Japan, which is defined as a magazine constructed underground and equipped with elevators of other transportation means. and is different from the usual tunnel type underground magazine.Explosions of explosives in model subsurface magazines were carried out. and explosion gases and shock waves blown out from their entrances were observed by schlieren photography. The blast overpressures were also measured by piezoelectric transducers. these external effects by explosion of explosives in the subsurface magazines were found to be less than those in the underground magazines.The above phenomena were simulated by numerical analysis using PISCES 2DELK code. Caluculated maximum overpressure and velocity of gases and shock waves were in fair agreement with their experimental values.
Synthesis of 3,3′‐Bis(2,2′,4,4′,6,6′‐Hexanitortilbene)
Authors: Zeng‐Gno Feng , Boren Chen 
Published: May 2005

AbstractThis paper describes the synthesis of 3,3′bis(2,2′,4,4′,6,6′‐hexanitrostilbene) (5). Based on the Ullmann reaction we prepared the title compound in nitrobenzene by using 3‐chloro 2,2′,4,4′,6,6′‐hexanitroztilbene (4) as the starting material and copper powder as the catalyst. (4) was reacted with hydrazine, not to yield a desired product, azo‐3,3′bist(2,2′,4,4′,6,6′‐hexanitrostilbene.) but to form a well‐known explosive, 2,2′,4,4′,6,6′‐hexanitrostibene (6). Differential scanning calorimetrical analysis has shown that (5) begins to decompose at the temperature of 298°C.
First steps towards a scientific approach to the Processing of Filled Polymers (Propellants)
Authors: Perez Daniel L. , Ramohalli Kumar N. R. , Rao Kanury R. K. , Fulian Chen 
Published: May 2005

AbstractThis research is directed towards a better understanding of filled polymer processing in general, and energetic composite solid propellants, in particular. The program established is composed of four stages and isolates batch processing as the technique to be examined. The first stage in the program is a thorough compilation of literally thousands of batch data for meaningful correlation and insight as to important areas within the process. Second is developing the fundamental equations governing the material for highly filled rheological suspensions and solving them numerically (biomodal particle distributions solely are to be considered). Third is the formulation of “model” compounds for experimental verification (this includes the use of perfectly spherical solid particles). Fourth and final is the implementation of this previous work to propellant manufacture. It is desired that from this work, new more economical means of predicting and also enhancing propellant performance can be developed.This paper presents the results of the completion of the first step within this program. A brief discussion of the latter steps is mentioned with respect to their progress. The results to be presented were funded from the College of Enginneering and Mines at the University of Arizona.
Thermal Decomposition of Energetic Materials. 43. Fast thermolysis of cubylammonium nitrate and cubane‐1,4‐diammonium dinitrate
Authors: Russell T. P. , Brill T. B. 
Published: May 2005

AbstractThe rapid thermal decomposition (dT/dt ≥ 70°C/s) of eubylammonium nitrate (CUBAN) and cubane‐1, 4‐diammonium dinitrate (CUBDAN) is described in terms of the temperature profile and gas products as a function of pressure (1‐200 psi Ar). In this environment the full strain energy of cubane is not released simultaneously with the redox reactions that involve the ammonium nitrate site because C2H4 and/or C2H2 are evolved. No large hydrocarbons form during rapid thermolysis, although both salts sublime to some extent below 7 psi Ar. CUBDAN is the only alkyldiammonium dinitrate salt that we have found to sublimduring fast thermolysis. An estimated gas phase basicity of about 215 kcal/mol for the cubylamines is obtained from the tendency to release HNO3(g). This value is surprising in light of the basicity values for other primary amines.
The Nitroglycerin Content Distribution in the coating of the solid propellant and the service life prediction of the charge
Authors: Heng Shu‐Yun , Pan Tong‐Xue , Kong Yang‐Hui , Liu Zi‐Ru 
Published: May 2005

AbstractIn this paper the distribution of the nitroglycerin (NG) content in the coating of solid double‐base propellant charge during various time at three aging temperatures were found by using thermogravimetric analysis (TG), and the separation and cracking of the coating were observed. The results showed that the differences of NG contents in the coating are significant and are a main reason giving rise to the separation and cracking of the coating. A empiric functional relation of NG content distribution in the coating to the thickness and aging time and temperature was obtained from measured data. On the basis of the NG contents in the boundary layer of the coating contracted with the propellant and times of separation or cracking of the coating. The service life of the charge was predicted.
Chromatographic determination of a polyol and/or sucrose octa‐acetate in CDB casting liquid
Authors: Keeton G. M. , Hooper A. P. 
Published: May 2005

AbstractA quantitative method for the determination of a polyol and/or sucrose octa‐acetate in cast double base (CDB) casting solvent formulations is presented. The procedure utilizing liquid chromatography is based on the separation of components by differences in molecular weight during the development of the method it became apparent that this analytical approach may be of general interest where a species to be a quantified has no other conveniently exploitable property.
Flammability limits and ballistic properties of fuel‐rich propellants
Authors: Shalom Abraham , Gany Alon 
Published: May 2005

AbstractThe flammability limits and ballistic properties of composite fuel‐rich propellants were studied experimentally, using PBAN/AP propellant formulations. Higher pressure and AP contents as well as smaller AP particle size were found to promote sustained combustion and to increase burning rate. The addition of potassium perchlorate (KP) in place of AP increased the burning rate pressure exponent from about 0.3 to over 0.7 at optimum conditions. Ferric oxide and copper chromite catalysts caused an increase of the burning rate by a factor of 2, while the addition of aluminum powder at the expense of the fuel binder was found to have a remarkable effect on the burning rate with a maximum increase of as high as 5‐fold.