Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Murray, J. S." wg kryterium: Autor

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-8 z 8
    Tytuł:
    Computational Characterization of a Potential Energetic Compound: 1,3,5,7-Tetranitro-2,4,6,8-tetraazacubane
    Autorzy:
    Politzer, P.
    Lane, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/357960.pdf
    Data publikacji:
    2011
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    1,3,5,7-tetranitro-2,4,6,8-tetraazacubane
    energetic performance
    density
    impact sensitivity
    Opis:
    The high densities and (strain-induced) enthalpies of formation of cage-type molecules have drawn attention to their polynitro derivatives as potential energetic materials. Several such compounds have been synthesized, including octanitrocubane and hexanitrohexaazaisowurtzitane. One that has not yet been prepared but has evoked continuing interest is 1,3,5,7-tetranitro-2,4,6,8- tetraazacubane. Some years ago, on the basis of a very high estimated density (about 2.19 g/cm3), it was predicted to have detonation properties greatly superior to those of HMX. We have now used computational procedures developed since that time to reassess the expected detonation performance of this compound. We find: density, 1.940 g/cm3; solid phase enthalpy of formation at 298 K, 757 cal/g; detonation velocity, 9.8 mm/µs; detonation pressure, 444 kbar; impact sensitivity, h50 ∼ 40 cm. These are all better than the corresponding values for HMX, but not by as much as had been estimated earlier.
    Źródło:
    Central European Journal of Energetic Materials; 2011, 8, 1; 39-52
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Computational Characterization of Two Di-1,2,3,4-tetrazine Tetraoxides, DTTO and iso-DTTO, as Potential Energetic Compounds
    Autorzy:
    Politzer, P.
    Lane, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/358276.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    DTTO
    iso-DTTO
    detonation properties
    impact sensitivities
    Opis:
    Abstract: The isomeric di-1,2,3,4-tetrazine tetraoxides DTTO and iso-DTTO have aroused considerable interest in recent years as potential energetic compounds, due to their predicted high densities and heats of formation and superior detonation properties. While neither has yet been synthesized, it has been suggested that the N→O linkages on alternate nitrogens will have a stabilizing effect. In the present study, we have reassessed the expected properties of DTTO and iso-DTTO. We fnd their anticipated detonation velocities and detonation pressures to be improved over HMX and similar to CL-20. The molecular surface electrostatic potentials of DTTO and iso-DTTO are consistent with the proposed stabilizing infuence of the N→O bonds. Furthermore, estimates of the available free space in the crystal lattices indicate that DTTO and iso-DTTO may be signifcantly less sensitive to impact than either HMX or CL-20.
    Źródło:
    Central European Journal of Energetic Materials; 2013, 10, 1; 37-52
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Computational Investigation of Amine Complexes of 2,4,6-Trinitrotoluene
    Autorzy:
    Politzer, P.
    Murray, J. S.
    Koppes, W. M.
    Concha, M. C.
    Lane, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/358818.pdf
    Data publikacji:
    2009
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    trinitrotoluene
    amine interactions
    hypergolic reactions
    Opis:
    Using the B3PW91/6-31G(d) computational procedure, we fnd two types of complexes to be formed between aliphatic amines and 2,4,6-trinitrotoluene (TNT). Type 1 are noncovalent, primarily electrostatic interactions that occur in the vicinities of the NO2 groups; Type 2 are δ-adducts, at carbons 1, 3 and 5. In Type 1, the TNT framework is very little affected. In Type 2, however, the site of the complex becomes quasi-tetrahedral, with longer bonds to its neighbors in the ring; the C-NO2 bonds are shortened. The Type 1 complexes have weakly negative (attractive) interaction enthalpies. For one of them, utilizing a chargetransfer formalism, we obtained a wave length for an electronic transition to a low-lying dative excited state that is in good agreement with observed values. The Type 2 interaction enthalpies are near-zero or even positive; however all of the complexes correspond to energy minima (no imaginary frequencies). For one of the Type 2, a transition state to a nitronic acid was found, with an activation enthalpy of only 5.6 kcal/mole. This indicates a possible route for amine-induced decomposition of TNT.
    Źródło:
    Central European Journal of Energetic Materials; 2009, 6, 2; 167-182
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Model-building adaptive critics for semi-Markov control
    Autorzy:
    Gosavi, A.
    Murray, S.
    Hu, J.
    Ghosh, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/91878.pdf
    Data publikacji:
    2012
    Wydawca:
    Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
    Tematy:
    adaptive critics
    learning algorithm
    semi-Markov process
    decision process
    Opis:
    Adaptive (or actor) critics are a class of reinforcement learning algorithms. Generally, in adaptive critics, one starts with randomized policies and gradually updates the probability of selecting actions until a deterministic policy is obtained. Classically, these algorithms have been studied for Markov decision processes under model-free updates. Algorithms that build the model are often more stable and require less training in comparison to their model-free counterparts. We propose a new model-building adaptive critic, which builds the model during the learning, for a discounted-reward semi-Markov decision process under some assumptions on the structure of the process. We illustrate the use of our algorithm with numerical results on a system with 10 states and a real-world case-study from management science.
    Źródło:
    Journal of Artificial Intelligence and Soft Computing Research; 2012, 2, 1; 43-58
    2083-2567
    2449-6499
    Pojawia się w:
    Journal of Artificial Intelligence and Soft Computing Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nitro Groups vs. N-Oxide Linkages: Effects Upon Some Key Determinants of Detonation Performance
    Autorzy:
    Politzer, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/358223.pdf
    Data publikacji:
    2017
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    C,H,N,O explosives
    detonation velocity
    detonation pressure
    N-oxides
    polyazines
    polyazoles
    detonation heat release
    crystal density
    heats of formation
    gaseous detonation products
    Opis:
    Increasing the nitrogen/carbon ratios in the molecular frameworks of C,H,N,O explosives has attracted considerable attention because it tends to result in more positive heats of formation and often greater densities. In conjunction with this, there has been a growing interest in N-oxide linkages, N+ → O−, as another source of oxygen in these compounds, in addition to or even possibly replacing NO2 groups. In this study, for a series of polyazines and polyazoles, we have compared the effects of introducing a single N-oxide linkage or NO2 group upon key properties that affect detonation velocity and detonation pressure. We found that: (1) The heats of formation per gram of compound, which is what is relevant for this purpose, are almost always higher for the N-oxides. (2) The nitro derivatives have greater densities and detonation heat releases. In relation to the latter, it must be kept in mind that increasing detonation heat release tends to be accompanied by increasing sensitivity. (3) The N-oxides produce more moles of gaseous detonation products per gram of compound.
    Źródło:
    Central European Journal of Energetic Materials; 2017, 14, 1; 3-25
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Some Perspectives on Estimating Detonation Properties of C, H, N, O Compounds
    Autorzy:
    Politzer, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/358498.pdf
    Data publikacji:
    2011
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    detonation velocity
    detonation pressure
    density
    enthalpy of formation
    detonation product composition
    explosives
    Opis:
    We have explored various aspects of the Kamlet-Jacobs equations for estimating detonation velocities and pressures. While the loading density of the explosive compound is certainly an important determinant of these properties, its effect can sometimes be overridden by other factors, such as the detonation heat release and/or the number of moles of gaseous products. Using a gas phase rather than solid phase enthalpy of formation in obtaining a compound's heat release can produce a signifcant error in the calculated detonation velocity. However a negative enthalpy of formation is not necessarily incompatible with excellent detonation properties. Additional evidence is presented to support Kamlet and Jacobs' conclusion that, for C, H, N, O explosives, assuming the detonation product composition to be N2(g)/H2O(g)/CO2(g)/C(s) gives overall quite satisfactory results.
    Źródło:
    Central European Journal of Energetic Materials; 2011, 8, 3; 209-220
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Role of Product Composition in Determining Detonation Velocity and Detonation Pressure
    Autorzy:
    Politzer, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/358258.pdf
    Data publikacji:
    2014
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    detonation velocity
    detonation pressure
    density
    detonation product composition
    detonation heat release
    Opis:
    Four sets of rules for predicting the detonation product compositions of explosives have been investigated: the Kamlet-Jacobs, the KistiakowskyWilson, the modified Kistiakowsky-Wilson and the Springall-Roberts. These can result, for a given compound, in significantly differing detonation products and amounts of heat release. However the resulting detonation velocities D and detonation pressures P obtained for the compound using the Kamlet-Jacobs equations are generally quite similar, with the Kamlet-Jacobs rules leading to the D and P that are, on average, closest to the experimental. The fact that the variations among the D and P values are relatively small can be attributed to a balancing of opposing effects relating to the quantities of gaseous products and the heat releases. Accordingly, obtaining reasonable accuracy for D and P does not necessarily imply corresponding accuracy for the product composition and heat release that were used. The analysis presented explains the observations that D and P can be correlated with loading density alone, even though product compositions are known to change with density.
    Źródło:
    Central European Journal of Energetic Materials; 2014, 11, 4; 459-474
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Tricyclic polyazine n-oxides as proposed energetic compounds
    Autorzy:
    Politzer, P.
    Lane, P.
    Murray, J. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/358097.pdf
    Data publikacji:
    2013
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
    Tematy:
    tricyclic polyazine N-oxides
    detonation performance
    sensitivity
    free space in crystal lattice
    molecular electrostatic potentials
    Opis:
    In designing proposed new explosives, we seek a balance between high detonation performance and low sensitivity. Accordingly we focus upon (1) planar molecules, for better packing efficiency and reduced shear strain upon impact/ shock, (2) high nitrogen content, for greater density and enthalpy of formation, (3) N→O linkages rather than NO2 or ONO2 groups as sources of oxygen, and (4) presence of NH2 groups, if possible, to increase density and diminish sensitivity. Here we report the results of a computational assessment of three tricyclic polyazine N-oxides that essentially satisfy these structural criteria. Their predicted crystal densities range from 1.96 to 2.03 g/cm3. The calculated solid phase enthalpies of formation are between 135 and 314 kcal/mol. The computed detonation velocities and detonation pressures are similar to HMX for two of the compounds and significantly greater for the third, exceeding even CL-20. Impact sensitivities were estimated on the basis of (1) the free space available in the respective crystal lattices, and (2) the molecular surface electrostatic potentials. All three compounds are expected to be less impact sensitive than both HMX and CL-20. One of the three in particular is suggested to represent the best balance between detonation performance and sensitivity.
    Źródło:
    Central European Journal of Energetic Materials; 2013, 10, 3; 305-323
    1733-7178
    Pojawia się w:
    Central European Journal of Energetic Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies