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Wyszukujesz frazę "Keshavarz, Mohammad Hossein" wg kryterium: Wszystkie pola


Wyświetlanie 1-5 z 5
Tytuł:
A Novel Approach for the Prediction of Electric Spark Sensitivity of Polynitroarenes Based on the Measured Data from a New Instrument
Autorzy:
Keshavarz, Mohammad Hossein
Powiązania:
https://bibliotekanauki.pl/articles/358523.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
electric spark sensitivity
RDAD
ESZ KTTV
polynitroarene
correlation
Opis:
This paper introduces two novel correlations for the assessment of the electric spark sensitivity of polynitroarenes based on a new instrument, marked as ESZ KTTV, which gives more reliable experimental data than a previous old system, marked as RDAD. The first correlation used the number of oxygen and chlorine atoms, as well as a correcting function that increases the predicted results based on elemental composition. Since the relationship between the measurements from ESZ KTTV and RDAD is not unequivocal, a second correlation can convert the reported data based on the RDAD system to the ESZ KTTV instrument. The second correlation can be applied to many available predictive methods, and provides the estimated results based on the RDAD instrument. For 34 polynitroarenes, where experimental values from both the RDAD and the ESZ KTTV instruments were available, the values of the root-mean-square deviation (RMSD) for the first and second correlations were 43.9 mJ and 36.0 mJ, respectively. Thus, due to the larger uncertainty in the measured data of the old RDAD system, both correlations provide more reliable data based on the ESZ KTTV instrument.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 1; 65-76
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the Thermal Decomposition Temperature of High-Energy Heterocyclic Aromatic Compounds in Order to Increase Their Safety during Storage, Handling and Application
Autorzy:
Keshavarz, Mohammad Hossein
Mousavi, Sajjad
Drikvand, Masoumeh
Powiązania:
https://bibliotekanauki.pl/articles/27788075.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
thermal decomposition temperature
heterocyclic aromatic compound
molecular structure
correlation
safety aspect
Opis:
Heterocyclic aromatic compounds containing various derivatives of five or six-membered nitrogen-containing rings, viz. triazoles, tetrazoles, furazans, triazines, and tetrazines, and some of their salts have been studied. High nitrogen content and a large positive heat of formation are two important properties of these compounds. Two new models are introduced for the reliable prediction of the thermal stability of these compounds through the thermal decomposition temperature (onset). The reported data for 181 compounds have been used to derive and test the new models. For a training set containing 132 heterocyclic aromatic compounds, the values of the average absolute deviation (AAD) and the coefficient of determination (R2) of the improved correlation were 9.72 K and 0.959, respectively. For triazoles, tetrazoles, furazans, triazines, and tetrazines, the predicted results of ADD and R2 for the external test data set for this model containing 41 compounds were 23.03 K and 0.664, respectively, which are closer to experimental data than those obtained by the core correlation, i.e. 26.49 K and 0.653, respectively. The correlation coefficients of cross-validation for leave-one-out (Q2LOO) and 5-fold (Q25CV) of the improved correlation were 0.955 and 0.951, respectively, which confirm that it is not an over-fitted model, robust and well-behaved.
Źródło:
Central European Journal of Energetic Materials; 2022, 19, 1; 39--62
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the Shelf Life of Composite Solid Propellants in Air and Nitrogen Atmospheres through Thermal Ageing
Autorzy:
Keshavarz, Mohammad Hossein
Hosseini, Seyyed Hesamodin
Mehran, Karimi
Powiązania:
https://bibliotekanauki.pl/articles/27787850.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composite solid propellant
inert atmosphere
dynamic mechanical thermal analysis
DMTA
damping
ageing
Opis:
This work introduces dynamic mechanical thermal analysis (DMTA) as an efficient method for the assessment of the shelf life of solid composite solid propellants in air and nitrogen atmospheres. The samples were aged at three temperatures 323.15, 333.15, and 343.15 K for 60, 120, and 180 days. The two different methods of Arrhenius and Berthelot were used to compare the effects of air and nitrogen atmospheres on the ageing of composite solid propellants. Damping (Tan δ) of composite solid propellants was used to determine the shelf life of the samples based on the loss of half of the physical property Tan δ (50% drop in damping). For the air atmosphere, the calculated activation energy for the degradation reactions of the samples was 86.26 kJ·mol–1. Both models, Arrhenius and Berthelot, confirmed that the shelf lives of the samples under the nitrogen atmosphere are more than four times those in an air atmosphere.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 1; 25--45
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Detonation Performance and Characteristics of 2,4,6-Trinitrotoluene Based Melt Cast Explosives Containing Aluminum by Laser Induced Breakdown Spectroscopy
Autorzy:
Rezaei, Amir Hossein
Keshavarz, Mohammad Hossein
Tehrani, Masoud Kavosh
Darbani, Mohammad Reza
Powiązania:
https://bibliotekanauki.pl/articles/358347.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
laser induced breakdown
spectroscopy
molecular structure
chemical analysis
Opis:
Aluminized melt cast formulations based on 2,4,6-trinitrotoluene (TNT) deliver an enhanced blast effect because the secondary combustion process of aluminum (Al) occurs beyond the detonation zone. A new method is introduced to assess the detonation performance and characteristics of aluminized TNT explosives on the basis of the laser-induced breakdown spectroscopy (LIBS) technique, in both air and argon (Ar) atmospheres. The plasma emissions of the prepared samples were recorded, where the atomic lines of Al, C, O and H as well as the molecular bands of AlO, CN and C2 were identified. A good discrimination and separation between the samples was possible using LIBS and principle component analysis (PCA), although they had similar atomic compositions. The quantitative calibration curve obtained using the relative intensity of Al/O was used to determine the detonation velocity/pressure and aluminum content of the TNT/Al samples. Comparisons between experimental and theoretical spectra were made using a Nelder–Mead temperature program for CN bands, which provided good agreement with the fitted spectra. Finally, CN vibrational temperatures were calculated from these spectral fittings. These temperatures have higher values in an Ar atmosphere than in an air atmosphere. Thus, increasing the oxygen concentration can decrease these temperatures in TNT/Al standard samples.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 1; 3-20
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stratigraphy and palaeoceanography of late Pleistocene molluscs from the northern coast of the Persian Gulf
Autorzy:
Gholamalian, Hossein
Hassani, Mohammad-Javad
Keshavarz, Musa
Powiązania:
https://bibliotekanauki.pl/articles/2185978.pdf
Data publikacji:
2022
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Pleistocene
Persian Gulf
Dayyer section
molluscs
palaeogeography
Opis:
We report an extraordinary discovery of marine Pleistocene strata from the north of the Persian Gulf. The Dayyer section contains a rich molluscan fauna including 26 bivalve species, Sr87/Sr86 data showing that the succession is not older than 153 ka (late Pleistocene). These strata are time-equivalents of the Bakhtiari Formation, but have a very different fossil content and facies. Comparing the Dayyer molluscan community to the present-day fauna of the Persian Gulf shows that many fossil species are absent in the recent waters. The palaeoceanographic distribution of the identified bivalves shows the presence of many of them in the Plio-Pleistocene strata of the Mediterranean Basin. This may point to a temporary connection between the Persian Gulf and Mediterranean Basin during the late Pleistocene and the extinction of many bivalves in the past 153 ka
Źródło:
Geological Quarterly; 2022, 66, 2; art. no. 17
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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