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Wyświetlanie 1-15 z 44
Tytuł:
Phase Stability of Ammonium Nitrate with Organic Potassium Salts
Autorzy:
Xu, Z.-X.
Fu, X.-Q.
Wang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358264.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ammonium nitrate(V)
phase transition
organic compounds
differential scanning calorimetry
Opis:
A study has been undertaken on the effect of additives on the phase transition of ammonium nitrate(V) (AN). Results obtained using Differential Scanning Calorimetry (DSC) showed that organic compounds and potassium salts of organic compounds have an effect on the phase transition behavior of AN. The samples were further analyzed using infrared (IR) and powder X-ray diffraction (XRD). The mechanism of phase stabilization of AN by compounds of this kind was examined. The present study showed that the influence of additives on the phase transition of AN occurs through the polar groups that are involved in intermolecular interactions of orbital and electrostatic types that form new hydrogen bonds. AN exists in only one phase in the temperature range from 30 °C to +100 °C, when a potassium salt of organic compounds was added. However, with organic compounds, the III→II phase transition was changed. IR and XRD of composites are characterized by new intermolecular interactions. Compacted samples of AN containing potassium salts of organic compounds exhibited better stability than AN containing organic compounds to multiple cyclic changes within a temperature range. This we named ‘freezing and thawing analysis’. Additives have two functions on the AN phase transition. First, solid solutions of AN mixture were formed for K+ replacement of NH4+. Second, hydrogen bonds formed, which caused AN and salts of organic compounds to interact intimately.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 3; 736-754
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
4-Amino-3-hydrazino-1,2,4-triazole: a Precursor for the Preparation of Divalent Energetic Materials
Autorzy:
Lin, Q.
Wang, P.
Sun, Q.
Lu, M.
Powiązania:
https://bibliotekanauki.pl/articles/951501.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic materials
detonation performance
nitrogen heterocycle
Opis:
4-Amino-3-hydrazino-1,2,4-triazole (AHT) was developed as a divalent cation. The multivalent structure can be used to increase the number of nitrogen-rich heterocycles, thereby increasing the heat of formation and improving the detonation performance. Herein we report on a family of divalent energetic salts, which exhibit excellent properties, viz. acceptable density, good detonation performance, and desirable thermal and impact stabilities. The structural features of the salts were further determined by single-crystal X-ray diffraction. In addition, the detonation properties calculated for these energetic salts identified them as competitively energetic compounds.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 18-29
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Simulations of the Effects of Droplet Size and Concentration on Vapour-Droplet JP-10/Air Detonations
Autorzy:
Liu, L.
Zhang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358150.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
multiphase detonation
discrete phase model
evaporation and breakup model
droplet size effect
initial concentration effect
Opis:
Two-dimensional simulations were conducted for JP-10 mono-dispersed vapour-droplet detonation in air, based on the detonation mechanism for clouds and validation of the extending critical droplet size limits in previous tests. In the simulations, the discrete phase model combined with the droplet evaporation and droplet breakup models was used. Utilizing a wide range of mono-dispersed droplet sizes and initial droplet concentrations, all cases of JP-10 droplets with a certain amount of pre-vaporized fuel can successfully achieve the deflagration to detonation transition. Detonation velocities at the equivalent concentration with droplet diameters no larger than 50 μm are in good agreement with the theoretical detonation velocities. The effects of droplet size and initial droplet concentration on the detonation behaviour were also investigated. Detonation velocities attained with droplet diameters below 50 μm appear to decrease very slightly with droplet size, but are almost equal to the velocity in gases. When the droplet diameter is above 50 μm, there is a decrease in simulated detonation velocity compared with fine droplets, and no secondary pressure peak was observed. For fuel-rich combustion, detonation velocities decrease rapidly with an increase in initial droplet concentration, and post-wave pressure fluctuation was obviously irregular, caused by the secondary local explosion of the droplets.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 175-190
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Explosion Parameters of Gaseous JP-10/Air Mixtures
Autorzy:
Zhang, Q.
Liu, X.
Powiązania:
https://bibliotekanauki.pl/articles/358896.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
JP-10
fuels
decane
explosion pressure
explosible limits
Opis:
This paper describes flammability measurements and data on the missile fuel, JP-10. The measurements include maximum explosion pressure, maximum rate of pressure rise and limiting flammability concentrations. Through a series experiments, the influences of the concentration of gaseous JP-10 in air on the explosion pressure and on the rate of explosion pressure rise have been analyzed, and the results are discussed. The explosion pressure of gaseous JP-10/air mixtures reached their highest values within the studied range at a concentration of 1.88%. The variation trends in the explosion pressure and the rate of pressure rise of gaseous JP-10/air mixtures with volume % appear similar. When the volume % of gaseous JP-10 lies in the range 0.5-1.8%, the explosion pressure and the rate of pressure rise for gaseous JP-10/air mixtures increase with the volume %, while in the range 1.8-5% these parameters decrease with the volume %. The flammability limits of gaseous JP-10/air mixtures are near those of gaseous n-decane/air mixtures. However, the maximum explosion pressure and the maximum rate of pressure rise of gaseous JP-10/air mixtures are much higher than those of gaseous n-decane/air mixtures.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 1; 261-270
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of Detonation Pressure and Velocity of Explosives with Micrometer Aluminum Powders
Autorzy:
Zhang, Q.
Chang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358334.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
aluminized explosives
detonation pressure
nonideal explosives
detonation velocity
Opis:
The data reported shows that the Chapman-Jouguet (CJ) detonation parameters of non-ideal explosives calculated from existing thermodynamic computer codes are significantly different from experimental results. We use CJ detonation theory to present a new approach predicting detonation pressure and velocity of aluminized explosives by thermodynamic detonation theory. There is no need to use the assumption of full and partial equilibrium of aluminum powder in reaction zones in the new approach. In this work the best agreement with experimental data was obtained by adjusting the parameter k in the Becker- Kistiakosky-Wilson equations of state (BKW-EOS). The detonation pressure and velocity values calculated by the present method agree well with the experimental results. All of the deviations for the calculated pressures of aluminized explosives are less than 9% and those for the detonation velocities are less than 7%.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 1; 77-86
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Predictive Method for the Heat of Explosion of Non-ideal Aluminized Explosives
Autorzy:
Zhang, Q.
Chang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358737.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
aluminized explosives
heat of explosion
thermodynamic
nonideal explosives
high energy materials
Opis:
The heat of explosion is one of the most important thermodynamic parameters of aluminized explosives. Two improvements in numerical calculations to predict the behaviour of the explosion of non-ideal aluminized explosives were completed in this work. The chemical reaction between aluminum and the C-J detonation products of high energy ingredients was determined and the equation of state for the detonation products of high energy ingredients was revised. The constant k in the BKW equation was revised to obtain perfect results for predicting the C-J parameters for high energy ingredients. The predicted results show that the heats and temperatures of aluminized explosives become maximized when the mass fraction of aluminum powder is 30%, which is in good agreement with the results obtained by empirical formulae.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 541-554
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Decomposition, Ignition and Kinetic Evaluation of Magnesium and Aluminium Fuelled Pyrotechnic Compositions
Autorzy:
Babar, Z.
Malik, A. Q.
Powiązania:
https://bibliotekanauki.pl/articles/358146.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
aluminium
magnesium
pyrotechnic mixtures
kinetic data
critical ignition temperature
Opis:
This paper describes the thermal, kinetic and ignition behaviour of three pyrotechnic mixtures comprising Al + Ba(NO3)2, Mg + NH4ClO4, and Mg + KMnO4. Aluminium (Al) and magnesium (Mg) are metal fuels whereas barium nitrate, potassium permanganate and ammonium perchlorate are oxidants. The main objective of the paper is to assess the safety and relative reactivity of these pyrotechnic combinations. The experimental results indicate that aluminium powder reacts exothermically with the decomposition products of barium nitrate near 601 °C. A similar kind of exothermic reaction takes place between magnesium powder and ammonium perchlorate at 338 °C. Heat flow data obtained from multiple heating rate experiments were used to calculate the kinetic parameters, such as activation energy, reaction rate constant and frequency factor, using the Kissinger method. Critical ignition temperatures of all three compositions have been estimated in order to evaluate their thermal stability. The results show that all of these compositions are thermally stable and their relative reactivity decreases in the following order: Mg + NH4ClO4 > Mg + KMnO4 > Al + Ba(NO3)2.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 579-592
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization and Application of Al/Ni Reactive Multilayers in Exploding Foils
Autorzy:
Wang, T.
Zeng, Q.
Li, M.
Powiązania:
https://bibliotekanauki.pl/articles/358516.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic material
Al/Ni reactive multilayer foils
bilayer thickness
exploding foil initiator
Opis:
A self-propagating reaction achieved by initiating an Al/Ni reactive multilayer foil can generate significant heat. The interdiffusion rate of the reactants plays an important role in the foils properties and is mainly affected by premixing and the bilayer thickness. The present research aims to characterize Al/Ni multilayer foils and to investigate their influence on an exploding foil initiator. Samples with different bilayer thicknesses were fabricated by magnetron sputtering. The heat released and the flame velocity were characterized. Foils with a stored energy of about 1100 J/g were prepared and the heat released revealed the existence of a 4 nm premixing layer. The analytical model proposed by Mann was employed to match the measured flame velocities; the fitted model showed good agreement with the experimental results. To make a comparison, Cu and Al/Ni exploding foils with the same bridge size were fabricated and tested in the identical discharge circuit. The results showed that the energy deposition ratio of an Al/Ni foil was 67-69%, while the value for Cu was only 39-45%, which indicated that Al/Ni multilayers could effectively increase the energy utilization of an initiator. Larger average flyer velocities were also observed with the Al/Ni initiators.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 3; 547-558
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the Detonation Parameters of Aluminized Explosives Based on a Disequilibrium Multiphase Model
Autorzy:
Pei, H.
Nie, J.
Jiao, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358535.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nonideal explosives
velocity of detonation
detonation pressure
relaxation timescale
Opis:
Detonation models are usually based on the classical Euler equations of gas dynamics under the assumption of thermodynamic equilibrium. However reported data show the Chapman-Jouguet (CJ) detonation parameters of nonideal explosives based on thermodynamic equilibrium codes are significantly different from experimental results. Based on the conventional CJ model, a new multiphase flow model, not in thermal equilibrium, was considered in this study. This approach was applied to compute the velocity of detonation for several aluminized explosives. The predictions are better than the CJ equilibrium model and are in excellent agreement with experimental data. All of the deviations for the velocity of detonation (VOD) are less than 4%.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 4; 491-500
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent Advances in the Study of the Initiation of Nitramines by Impact Using Their 15N NMR Chemical Shifts
Autorzy:
Jungová, M.
Zeman, S.
Yan, Q.-L.
Powiązania:
https://bibliotekanauki.pl/articles/358278.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
impact sensitivity
initiation
15N NMR chemical shifts
Opis:
The relationship between the 15N NMR chemical shifts of aza nitrogen atoms in twelve nitramines and the impact sensitivity of these compounds, expressed as the drop energy, Edr, has been analyzed from the point of view of recently published findings. This relationship appears to be the best method for identifying the key atoms at the reaction centre of a given molecule. These atoms might be taken as “chemical hot spots”. The absence of any solid state influence on the chemical shifts, which were here determined in solution, does not have a fundamental influence on the reaction centre identification. The relationship discussed here confirms the close molecular structural dependence for drop energies (impact sensitivities) obtained for individual energetic materials (EMs) by means of a standard impact tester (Julius Peters) with the detection of the 50% probability of initiation based on acoustic detection. The dependence of impact sensitivity on specific crystal surfaces, using samples of individual EMs obtained by screening, should be investigated more extensively.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 383-393
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent Advances in the Study of the Initiation of Energetic Materials Using the Characteristics of Their Thermal Decomposition Part II. Using Simple Differential Thermal Analysis
Autorzy:
Zeman, S.
Yan, Q.-L.
Elbeih, A.
Powiązania:
https://bibliotekanauki.pl/articles/358712.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
activation energy
detonation velocity
DTA
explosives
initiation
nitramines
PBX
thermal decomposition
Opis:
Simple Differential Thermal Analysis (DTA), with evaluation of its output by the Kissinger method, was used in the case of emulsion explosives and, as an advanced application, for several plastic bonded explosives (PBXs). In both of these kinds of explosive the square of their detonation velocities, D2, is used as their performance characteristic. A relationship between the slope of the Kissinger equation, EaT-1, and the D2 values makes it possible to formulate a possible mechanism for the initiation of emulsion explosives. Regarding PBXs, it would seem possible to postulate a change in the detonation chemistry of plastic bonded nitramines, depending on the pressure and temperature in the zone of the detonation wave, particularly in the case of CL-20 fillers. Binders with aromatic building units in their macromolecular structure seem to be less-favoured in terms of their thermal reactivity and performance than the final PBXs. These findings document the advantages of the above-mentioned application of simple DTA.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 395-404
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent advances in the study of the initiation of energetic materials rusing characteristics of their thermal decomposition. Part I, Cyclic nitramines
Autorzy:
Zeman, S.
Yan, Q.-L.
Vlček, M.
Powiązania:
https://bibliotekanauki.pl/articles/358411.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
arrhenius parameters
detonation velocity
explosives
initiation
manometric method
nitramines
Opis:
Arrhenius parameters, Ea and log A, of 17 cyclic nitramines, derived from the Russian vacuum manometric method (SMM) and compatible thermoanalytical methods, have been used in this study. The detonation velocity, D, at maximum theoretical crystal density, of the nitramines in this study was taken as a characteristic of their detonation. On the basis of known relationships between their Ea and D2 values (modified Evans-Polanyi-Semenov equation), the specific influence of some physicochemical properties on their thermal decomposition was shown. A new logarithmic relationship was found between the rate constant k, of the unimolecular thermal decomposition of the nitramines studied at 230 °C, and their D values. A fundamental characteristic of this new relationship rests on the equivalency of the primary fission processes in the low-temperature thermal decomposition and on the detonation initiation of the nitramines under study. Both these relationships confirm the problems encountered in the kinetic specification of the thermal decomposition of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (HNIW, CL-20) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). These problems, and also the possible influence of the pre-decomposition states on the thermal decomposition of the nitramines studied, are discussed.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 173-189
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Modified Penetration Model for Copper-Tungsten Shaped Charge Jets with Non-uniform Density Distribution
Autorzy:
Elshenawy, T.
Elbeih, A.
Li, Q. M.
Powiązania:
https://bibliotekanauki.pl/articles/358894.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
shaped charge
jet penetration
virtual origin
non-uniform density distribution
Opis:
The penetration of a shaped charge jet with non-uniform density distribution was studied. The virtual origin model, which assumes a constant jet density, was modified to include the situation where the jet density deficit/reduction of an un-sintered copper-tungsten powder jet causes a non-uniform jet density distribution. A relation between the relative density ratio and the normalised jet velocity is proposed, based on which an analytical solution of the modified virtual origin model is obtained. The validity of the modified virtual origin model was demonstrated by its largely improved prediction in comparison with experimental and numerical results. It showed that the density reduction term reduces the penetration depth by 16.58% for an un-sintered copper-tungsten powder jet.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 927-943
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combustion Characteristics and Mechanism of Boron-based, Fuel-rich Propellants with Agglomerated Boron Powder
Autorzy:
Xu, H. -X.
Pang, W.-Q.
Guo, H.-W.
Zhao, F.-Q.
Wang, Y.
Sun, Z.-H.
Powiązania:
https://bibliotekanauki.pl/articles/358733.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
analytical chemistry
boron-based fuel-rich solid propellants
agglomerated boron powder
combustion performance
combustion mechanism
Opis:
In order to extend the burning rate of boron-based, fuel-rich solid propellants with agglomerated boron powder, the effects of the boron content, the AP content, and of the magnesium powder content, on the burning rate and pressure exponent have been studied systematically. It has been shown that when the AP content is constant, the burning rate of the propellants increases with an increase in the agglomerated boron content. Furthermore, the burning rate and pressure exponent increase with increasing the contents of AP and magnesium powder. By means of single colour frame amplification photography and combustion wave tests, the combustion mechanism of these propellants has been investigated. It has been shown that the flame of the propellants becomes brighter by increasing the AP content, the dT/dxcp and dT/dxgp of the propellant FR-5 being around 6815 and 5789 °C/mm respectively, higher than those of FR-4, resulting in greater burning rates. The Ts of these propellants is above 683 °C, which is higher than the decomposition peak temperatures of agglomerated boron powder and of propellants (about 649 °C), which indicates that agglomerated boron powder is partially oxidized on the combustion surface, and the heat released from it may be beneficial to the combustion of the propellants.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 4; 575-587
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pre-formulation Compatibility Studies of 5-Amino-1H-tetrazole Nitrate with Several Typical Materials by Thermal and Non-thermal Techniques
Autorzy:
Guo, W.
Han, Z.
Lin, Q.
Wang, B.
Powiązania:
https://bibliotekanauki.pl/articles/358375.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
5-ATN
compatibility
energetic materials
Opis:
The aim of the present study was to assess the physicochemical compatibility of a promising energetic salt, 5-amino-1H-tetrazole nitrate (5-ATN), with some typical materials. Thermal techniques (differential scanning calorimetry (DSC) and vacuum stability test (VST)) and non-thermal techniques (X-ray diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR)) were applied. Five energetic materials (TNT, RDX, HMX, CL-20 and AP) and three common additives (Al, DOS and F2604-2) were tested to evaluate their compatibility with 5-ATN. Based on the DSC results, except for AP that was only partially compatible with 5-ATN, all of the selected materials exhibited good compatible with 5-ATN. The VST test further confirmed the compatibility of the 5-ATN/AP mixtures. Combined with the thermal methods, the FTIR results agreed with the DSC findings. The XRD results showed some differences.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 1; 100-114
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 44

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