bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Production of Decaborane‐14 from Diborane by Laser Induced Chemistry
Authors: Merritt J. A. , Meyer H. C. , Greenberg R. I. , Tanton G. A. 
Published: May 2005

Abstractn‐Hexylcarborane (NHC) is the proposed burning rate modifier for improved propellants to be used in the next generation of missiles. The synthesis of this material requires decaborane‐14, a material that is not commercially available in large quantities now. Therefore, the cost‐effectiveness of synthesized NHC, as it relates directly to the missile cost, depends upon a low‐cost synthesis of decaborane‐14. Laser induced chemistry, a revolutionary new kind of chemistry, offers a much more efficient and less expensive way to synthesize compounds than conventional thermochemistry provides. Using this technique, we have synthesized decaborane‐14 from diborane in high yields and high purity using both CO2 and DF laser frequencies. The products are decaborane‐14 formed as white crystals and pentaborane‐9 in the gaseous state; thus, isolation of the decaborane‐14 is a simple chemical engineering procedure.
The Assay of 1‐Ammonium‐3,5‐Dinitro‐1,2,4‐Triazole and its determination in mixtures with ammonium nitrate
Authors: Selig W. 
Published: May 2005

AbstractAmmonium dinitrotriazole has been assayed by nonaqueous titration as an acid in dimethylsulfoxide versus tetrabutylammonium hydroxide. It can also be assayed by nonaqueous titration as a base in glacial acetic acid versus perchloric acid in glacial acetic acid. In mixtures with ammonium nitrate, ammonium dinitrotriazole can be determined by potentiometric titration in aqueous solution versus cetylpyridinium chloride.
Structure moléculaire des dérivés nitrés aromatiques. I. Etats électroniques singulets du mono et du 1,3,5‐trinitrobenzène
Authors: Boileau J. , Blain M. , Odiot S. , Leclercq J.‐M. , Fliszar S. , Vergoten G. , Fleury C. 
Published: May 2005

AbstractLes états électroniques singulets du nitrobenzène et du T.N.B. ont été calculés en fonction de la vibration de valence du ou des groupements CNO2, par calcul C.N.D.O/S avec I.C. incluant mono et biexcitations. Le tracé des courbes correspondantes est obtenu ponctuellement à partir du niveau fondamental calculé en S.T.O. 3 G.
Simulation numérique du comportement viscoélastique non‐linéaire d'un materiau explosif
Authors: Belmas R. , Reynaud J. , Sorel J. 
Published: May 2005

AbstractNous présentons le principe de deux modèles rhéologiques utilisés dans notre programme de calculs de structures par éléments finis pour décrire le comportement des matériaux agrégataires explosifs.La viscoélasticité linéaire permet de prendre en compte les phénomènes liés au temps et à la température par l'intermédiaire d'une loi d'équivalence temps‐température ainsi que l'histoire du matériau. La validité de ce modèle est cependant limitée aux domaines de linéarité des matériaux, assez réduits, le plus souvent.La viscoélasticité non‐linéaire permet de pallier cet inconvénient et de décrire le comportement du matériau depuis l'état de repos jusqu'à la rupture. La non‐linéarité de ce modèle est fondée sur l'utilisation d'une équivalence temps‐pression et temps‐endommagement.Diverses comparaisons calcul‐expérience viennent confirmer la validité de ce dernier modèle sur toute la gamme d'utilisation du matériau.
On the Behaviour of Nitrate Esters in Acid Solution. II. Hydrolysis and oxidation of nitroglycol and nitroglycerin
Authors: Camera E. , Modena G. , Zotti B. 
Published: May 2005

AbstractThe behaviour of ethylene glycol dinitrate (nitroglycol) and nitroglycerin in moderately concentrated aqueous sulphuric acid, as models of “spent acids”, has been studied. The nitrate esters initial reaction is the simple hydrolysis to yield the alcohols which are eventually oxidized by nitric acid. This reaction, however, is unmeasurably slow in the absence of nitrous acid.
Generation of Free Radicals in RDX and HMX Compositions
Authors: Miles M. H. , Devries K. L. , Britt A. D. , Moniz W. B. 
Published: May 2005

AbstractEfforts to generate detectable concentrations of free radicals in explosives, binders, and their mixtures are described. Radicals were readily produced in polycaprolactone and polyethylene glycol binders at liquid nitrogen temperature using stresses as low as 0.4 kbar. These radicals were all of the peroxy type, and presumably formed by reaction of mechano‐radicals with oxygen present in the polymer. No mechano‐radicals were observed from HMX or RDX using samples cooled to liquid nitrogen temperature and applied stresses up to 4 kbar. In neither impacted samples that failed to explode nor the residues remaining after a partial explosion were radicals detected by ESR.Low temperature γ‐irradiation of these materials was also carried out. Free radical signals originating in both the polymer and the explosive could be identified. The reactivity of NO2 radicals from γ‐irradiated HMX is enhanced in the presence of binder. In γ‐irradiated HMX/polycaprolactone mixtures, the NO2 radical anneals rapidly at 150 K, versus 240 K for HMX alone.Evidence is presented to suggest that the relatively stable NO2 radical (such as produced by γ‐irradiation) in HMX does not play a dominant role in mechanical initiation.
Het powders, Propellants with Controlled Temperature Dependence
Authors: Oversohl W. 
Published: May 2005

AbstractAfter a general survey of conventional propellants, there will follow a description of the HET propellants. HET powders are propellants of heterogeneous structure. They are characterized by the powder granules worked into powder basic masses. The powder granules may be grains of single‐base, double‐base or triple‐base propellants. Single‐base powder basic masses are suited to take up a maximum of 70% granules. Granule percentages of about 50% have found to be most efficient. In the case of HET propellants with single‐base matrix, their temperature dependence can be present at discretion, i.e. with neutral of negative temperature exponent, by the type, grain size and percentage of the granules worked in. HET propellants with single‐base powders as basic masses can be produced with explosion heat values of up to 4300 Joule/g. Their manufacture does not present any problems and it is easy from the technical point of view. As full‐strip propellants, the HET types with single‐base powders as basic masses have progressive burning characteristic. HET propellant types are suited also for the manufacture of maccaroni and strip powder. The free‐flowing powder types can be surface coated as usual.
Possibilities for the Detonation of Porous, Fine‐Grained Smokeless powders
Authors: Strnad J. , Gavlas J. , Malkovský K. 
Published: May 2005

AbstractThis article describes a potential cause of detonation in fine‐grained smokeless powders during the production of propelling charges for hunting (lead shot) ammunition, the tests performed in order to deter‐mine this cause, the general possibilities for the deflagration‐to‐detonation transition (DDT) in smokeless nitrocellulose powders, and finally a practical method for determining the predetonation zone with the deflagration of condensed explosives.
Calorimetric Evaluation of Some Variables in Black Powder Making
Authors: Morrow S. I. , Haywood B. 
Published: May 2005

AbstractHand‐made, charcoal‐containing black powders exhibited higher heats of combustion than commercial black powders; the values were also higher than values previously reported in the literature. However, commercial pellets attained maximum pressure in a closed bomb upon ignition more rapidly and had better physical integrity than the char‐coal‐containing laboratory products. When channel and furnace blacks were used instead of charcoal, pellets with excellent physical integrity were obtained. These products had lower heats of reaction than commercial black powder and also developed maximum pressure in a closed bomb more slowly. Although adding a small amount of water before or during grinding of mixtures of carbon, sulfur, and potassium nitrate did not affect the heat of reaction of the product significantly, this may have caused the density of some of the products to be abnormally low. Colloidal silica showed promise of being a useful additive in black powder manufacture.
Calculations of Explosion and Detonation Parameters of Explosives
Authors: Niksiński A. , Karczmarewicz A. , Karmiński W. 
Published: May 2005

AbstractComparative results of explosive decomposition equation and explosion parameter calculations of several high explosives are described. Calculations were carried out by two different algorithms. Results of calculations are compared with literature data. Some corrections of simple Kamlet's formulae for detonation parameter calculations are proposed adjusting the formulae to calculated explosion parameters.
A Study on Thermodynamic Functions of Detonation Products
Authors: Xiong Wu 
Published: May 2005

AbstractThermodynamic parameters of detonation products were calculated using functions based on the enthalpy H0 − H. The results are compared to the experimental data and discussed with respect to other methods. Within the same temperature range the accuracy was considerably improved. The coefficients for the thermodynamic functions of detonation products are given in an appendix.
Preparative and mechanistic studies on unsymmetrical Dimethyl Hydrazine‐Red Fuming Nitric Acid Liquid Propellant Gels
Authors: Munjal N. L. , Gupta B. L. , Varma Mohan 
Published: May 2005

AbstractThixotropic gels of unsymmetrical dimethyl hydrazine (UDMH) have been prepared using methyl cellulose (4.48 wt%) and agar‐agar (0.64 wt%) chemical gelling agents. Red fuming nitric acid has been gelled by using sodium silicate (4.25 wt%).The effect of various parameters like size of container, particle size of gellants and temperature on gellation time of UDMH gelled system has been investigated. The gellation time of UDMH gel is found to increase with the increase in the internal diameter of the container. Gellation time is found to show direct proportionality with the particle size when methyl cellulose is used as gellant. In case of methyl cellulose, the gellation occurs quickly at higher temperature whereas the reverse trend is observed when agar‐agar gellant is used.In order to boost the performance of liquid propellants, the metallized gels of UDMH containing Al (10‐40 wt%) and Mg (10‐25 wt%) metal powders have been prepared. The density measurements of virgin and metallized gels reveal that there is a maximum gain of 46.72% and 19.3% over virgin gels on incorporation of Al and Mg powders respectively.Efforts have been made to understand the process of gellation using optical and photomicrographic techniques.
Rheological Studies on Virgin and Metallized Unsymmetrical Dimethyl Hydrazine Gelled Systems
Authors: Gupta B. L. , Varma Mohan , Munjal N. L. 
Published: May 2005

AbstractRheological studies on unsymmetrical dimethyl hydrazine‐methyl cellulose gelled system have been conducted under varying shear rates in order to establish its flow characteristics. The gel is found to behave as a pseudoplastic thixotrop. The viscosity build‐up with respect to time has been traced till apparently a firm gel is set. The viscosity is found to increase with time rapidly in the beginning and minor changes are observed thereafter. The effect of temperature and extent of metal (Al and Mg) loading on apparent viscosity of the gelled system has also been investigated. Both the apparent viscosity and thixotropic character of the virgin gel are found to decrease with increase in temperature. An increase in rate of shear decreases the apparent viscosity significantly. The thixotropic character of the metallized gelled systems is observed to increase with metal content and that they exhibit a shearthinning behaviour too. Power law has been applied to assess the variation of pseudoplastic index n and consistency index K with temperature and metallization. The results reveal that n increases with temperature and decreases with metal loading whereas K shows an opposite trend. The yield value of gelled systems is noted to show decrease with temperature and increase with metal incorporation.
Combustion of Energetic Fuel for Ducted Rockets (I)
Authors: Kubota N. , Kuwahara T. 
Published: May 2005

AbstractEnergetic solid fuels composed of modified GAP (glycidyl azide polymer) propellants were formulated in order to obtain optimized combustion characteristics for variable flow ducted rockets. Burning rate in a primary combustor and the combustion efficiency in a secondary combustor were studied and evaluated as a function of the mixture ration of fuel and air. The energetic fuels consisting of – N3 groups in its chemical structure burned very rapidly even though the combustion temperature was low when compared with conventional solid propellants for rockets. The pressure exponent of the burning rate was optimized to gain wide range of mass generation rate. The combustion gases generated in the primary combustor burned very efficiently in a secondary combustor. The effective specific impulse of the ducted rockets was obtained to be about 780 s.
Pressure‐Temperature Phase Diagram of 1,4‐Dinitrocubane
Authors: Piermarini G. J. , Block S. , Iyer S. , Damavarapu R. 
Published: May 2005

AbstractThe pressure‐temperature reaction phase diagram for 1,4‐dinitrocubane (DNC) was determined utilizing optical polarizing microscopy and Fourier transform infrared (FTIR) spectroscopy in conjunction with a high pressure diamond anvil cell and the ruby fluorescence method of pressure measurement. A second‐order structural phase transition from α‐DNC to ß‐DNC has been identified and its pressure dependence determined. The transformation is of an order‐disorder type.
Characterization of plastic‐bonded explosives by pyrolysis gas chromatography and multivariate data analysis part II: Aging studies
Authors: Rietjens M. , Wils E. R. J. 
Published: May 2005

AbstractApplication of Curie point pyrolysis gas chromatography (Py‐GC) and principal component analysis (PCA) in combination with a new normalization method could show the presence of patterns in PCA score plots not visible with the commonly used normalization method. In the first four principal components (PC's), two patterns were observed which could be attributed to aging and the crosslink density (CD). Aging of PBX samples has a complex effect on the peak loadings on PCI and are difficult to reveal. This in contrast to the peak loadings on PC3 and PC4 where both PC's are dominated by only one compound (respectively, C5H6 and cyclohexene). This means that the formation of both these compounds proceeds independently from each other, i.e., by different mechanisms. It was shown that aging is slowed down in samples containing more of the antioxidant Flexzone. From the correlation matrix a few compounds were found to have very high correlations (> 0.98). This was the case for methane, propane and n‐butane in both unaged and aged samples indicating that these compounds do not originate form moieties that are affected by aging. Also, cis‐ and trans‐butene have such high correlations and were formed in a 0.86:1 ratio, probably through the same mechanism. The absolute intensities decrease upon aging suggesting that both compounds originate form those parts of the polymer that are sensitive to aging. PC2 was related to saturated and unsaturated hydrocarbon compounds. The unsaturated compounds result from the elimination of water (free OH groups) from samples with CD values below 1.
Effect of density gradient and porosity on HMX/TNT pressure cast shaped charge performance
Authors: Gharia J. S. , Kumar A. S. , Raghavendra L. N. , Vadali S. R. 
Published: May 2005

AbstractPrecision shaped charges are prepared adopting pressure casting technique. Porosity and voids in such charges which may not be detected by X‐ray radiography would substantially effect the shaped charge performance. The effect of porosity on the parameters like density, VOD, CJ pressure and jet tip velocity have been predicted. Density variation in the charges prepared under different experimental conditions has been determined and compared with that of the predicted values in this paper.
Boron carbide combustion in solid‐fuel ramjets using bypass air. Part I : Experimental investigation
Authors: Natan Benveniste , Netzer David W. 
Published: May 2005

AbstractThe effects of bypass air on the combustion of highly loaded boron carbide/HTPB fuel grains in a solid‐fuel ramjet motor were investigated experimentally. It was found that combustion efficiency can be significantly increased by employing high bypass rations with low dump momentum. The results indicated that high bypass dump momentum causes the particles to collide with the wall and extinguish. Increasing pressure increased efficiency, apparently through the resulting increased residence time. Increased overall equivalence ratio (grain length) also was found to be beneficial, the result of a smaller percentage of larger particles which are generated in the recirculation zone. Some of the reduction in combustion efficiency was determined to be due to incomplete combustion of the HTPB rather than just to the incomplete burning of the boron carbide particles.
Boron carbide combustion in solid‐fuel ramjets using bypass air. Part II: Theoretical analysis
Authors: Natan Benveniste , Netzer David W. 
Published: May 2005

AbstractThe effect of bypass air momentum on the combustion efficiency of a boron‐carbide fueled solid‐fuel ramjet motor has been investigated theoretically. A 3‐D model of the flow in the aft‐burner has been developed and solved numerically. The theoretical results indicated that combustion efficiency can be increased by employing bypass air with low dump momentum, in agreement with experimental results. High bypass air dump momentum was shown to enhance extinguishment of particle combustion through increased collisions with the motor walls.
Sugar derivatives containing oxiranes and α,β‐unsaturated γ‐lactones as potential environmentally friendly insecticides
Authors: Justino Jorge , Rauter Amélia P , Canda Tana , Wilkins Richard , Matthews Elizabeth 
Published: May 2005

AbstractA range of novel sugar derivatives containing oxiranes or α,β‐unsaturated γ‐lactones in their structure were evaluated as potential insecticides with the added possible benefit of being benign in the environment. A number of arthropod species were chosen to represent those in the terrestrial, aerial and aquatic environments, covering target adult insects such as Musca domestica L (housefly) and Trialeurodes vaporariorum (Westwood) (glasshouse whitefly), which are public health and horticultural pests, Drosophila melanogaster Meig (fruitfly), both adult and larva, and a marine non‐target crustacean, Artemia salina L. The tested compounds possessed efficacy and selectivity against these insect species, but were not toxic to brine shrimps, a reference organism in assays to evaluate the potential toxicity hazard to invertebrates in ecosystems. Copyright © 2005 Society of Chemical Industry
Performance of the reduced‐size polarized Z3PolX basis set in calculations of vibrational polarizabilities, infrared, and Raman intensities: Application to formaldehyde molecule
Authors: Zaleśny Robert , Bartkowiak Wojciech 
Published: May 2005

AbstractIn the present study we report on the results of calculations of pure vibrational polarizability and hyperpolarizability within the double‐harmonic oscillator approximation for the formaldehyde molecule. The results of calculations of the infrared (IR) and Raman intensities are presented as well. The main goal of this investigation was to check the performance of a newly developed reduced‐size polarized Z3PolX basis set. The calculations were performed using the Hartree–Fock (HF) method and the second‐order Møller–Plesset (MP2) perturbation theory with several correlation consistent basis sets. It was found that in the case of formaldehyde, the electron correlation is crucial to reproduce the sign of β. Moreover, the overall performance of the Z3PolX basis set was satisfactory with the enormous reduction of computational time in comparison with correlation consistent basis sets. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Theoretical modeling of the peroxide stretch in H2O2, F2O2, and Fe2O4
Authors: Bacelo Daniel E. , Binning R. C. 
Published: May 2005

AbstractThe structures and harmonic vibrational spectra of H2O2, F2O2, Fe2O4, and Fe2O4(H2O)6 have been examined in theoretical electronic structure calculations. A variety of density functionals and basis sets have been employed to sample the consistency to be expected in calculations on peroxodiiron (III) complexes. It is found that both Gaussian function and numerical basis sets are capable of satisfactory accuracy in determining geometries and vibrational frequencies. Several density functionals fit the experimental vibrational spectra of H2O2 and F2O2 adequately; the BPW91 functional provides the best overall fit. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Improving the efficiency of table‐driven CI
Authors: Harris Frank E. 
Published: May 2005

AbstractKhait and Hoffmann Int J Quantum Chem 2001, 81, 130 have proposed improvements to the efficiency of the table‐CI method of Buenker and co‐workers for handling spin‐adapted functions in configuration‐interaction studies of open‐shell systems. It is shown that significant further efficiency can be obtained by using methods and formulas published nearly 40 years ago by the present author. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Variational treatment on the energy of the He‐sequence ground state with weakest bound electron potential model theory
Authors: Ma Dong‐Xia , Zheng Neng‐Wu , Fan Jing 
Published: May 2005

AbstractThe concept of spin–orbital of the weakest bound electron is described used to construct the antisymmetric wave function of atomic or ionic systems within weakest bound electron potential model theory (WBEPM theory). The total energies of He‐sequence (Z = 2–9) in the ground states is calculated with a variational method. The effect of fixed orbital approximation is discussed quantitatively. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
B3LYP density functional study on spectroscopic properties of CuO− and CuS−
Authors: Midda S. , Bera N. C. , Das A. K. 
Published: May 2005

AbstractSpectroscopic constant and molecular properties of CuO− and CuS− in their ground state were studied in detail using hybrid the HF/DF B3LYP density functional method. Four basis sets of Cu, one of them fully uncontracted, were used for this calculation. The basis sets for O and S are correlation consistent basis sets. The basis sets were developed systematically in order to see the effect of basis sets on the spectroscopic properties and also to check the consistency of the calculated properties. The B3LYP spectroscopic properties of CuO− agree very well with the only available experimental values. Most of the spectroscopic properties of CuO− and particularly those of CuS− are reported for the first time. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005