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Wyszukujesz frazę "thermal sensitivity" wg kryterium: Temat


Tytuł:
Wrażliwość termiczna mieszanin azotanu(V) amonu z wybranymi składnikami materiałów wybuchowych stosowanymi w górnictwie
Thermal sensitivity of mixtures of ammonium nitrate(V) with some components of explosives applied in the mining industry
Autorzy:
Sałaciński, T.
Maranda, A.
Powiązania:
https://bibliotekanauki.pl/articles/164951.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Górnictwa
Tematy:
wrażliwość termiczna
materiały wybuchowe
azotan(V) amonu
thermal sensitivity
explosives
ammonium nitrate(V)
Opis:
Celem pracy było określenie istotności wpływu właściwości chemicznych i zawartości wybranych składników materiałów wybuchowych stosowanych w górnictwie (MWG) na wrażliwość termiczną MWG, poprzez zbadanie wpływu tych składników na charakter rozkładu termicznego azotanu(V) amonu. Mieszaniny dwuskładnikowe otrzymywano przez mechaniczne wymieszanie roztartej rolniczej granulowanej saletry amonowej z reprezentantami wybranych grup składników MWG. Poddano analizie przesunięcia temperatur początków topnienia i rozkładu ww. mieszanin, wyznaczając wartości tych temperatur metodą różnicowej analizy termicznej (DTA) dla próbek o masie rzędu 30 mg, w otwartych probówkach szklanych i przy szybkości ogrzewania 5ºC/min. Określono charakter zależności pomiędzy zawartością wybranych typów dodatków a wrażliwością termiczną azotanu( V) amonu. Jako podstawę analizy przyjęto wyniki uzyskane dla mieszanin równowagowych (1 : 1).
The aim of this work was to determine the importance of the influence of chemical properties as well as of content of some components of explosive materials applied in mining industry (so call blasting explosives) on thermal sensitivity of these blasting explosives. The task was completed by testing the influence of this components on the nature of ammonium nitrate thermal decomposition. Two-component mixtures were obtained by mechanical mixing of grinded fertilizer-grade ammonium nitrate with representatives of some groups of blasting explosives components. Shifting onset temperatures of melting and decomposition peaks was determined by Differential Thermal Analisis (DTA), for ca. 30 mg samples, in open glass test-tubes and with heating rate of 5 ºC/min. The nature of the relationship between the content of some kind of components and the thermal sensitivity of ammonium nitrate(V) has been determined. The results obtained for 50 wt.% mixtures (1 : 1) were taken as the basis of the analysis.
Źródło:
Przegląd Górniczy; 2017, 73, 3; 71-76
0033-216X
Pojawia się w:
Przegląd Górniczy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insensitive HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) Nanocrystals Fabricated by High-Yield, Low-Cost Mechanical Milling
Autorzy:
Wang, Y.
Jiang, W.
Song, X.
Deng, G.
Li, F.
Powiązania:
https://bibliotekanauki.pl/articles/358912.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nanoexplosives
HMX
thermal decomposition
sensitivity
Opis:
A mechanical approach had been adopted for fabricating HMX nanoparticles. This fabrication method avoided the recrystallization process and was different from the traditional methods employed to prepare nanoexplosives. In particular, the high yield and low cost increased the possibility of its industrial application. Specifcally, HMX particles, that had a mean size of 0.27 μm, were prepared by mechanical milling; a signifcant proportion of nano-HMX (<100 nm) were present and these were observed by TEM and SEM images. The thermal decomposition of HMX samples before and after pulverization was investigated by TG/DSC analysis. The results indicated that there was no obvious difference between the thermographs of raw and pulverized HMX. The HMX samples were investigated by friction, impact, and shock sensitivity tests. High safety was confrmed since pulverized HMX was far more insensitive than raw HMX; indeed the shock sensitivity of pulverized HMX was about 60 percent lower than that of raw HMX.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 2; 277-287
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Path to ε-HNIW with Reduced Impact Sensitivity
Autorzy:
Elbeih, A.
Husarova, A.
Zeman, S.
Powiązania:
https://bibliotekanauki.pl/articles/358508.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HNIW
crystallization
thermal stability
impact sensitivity
SEM
Opis:
New purification method was applied to obtain epsilon HNIW (ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane, ε-HNIW) which has low impact sensitivity. The method is based on removing the impurities from a solution of alpha HNIW (ε-HNIW) by a chemical reaction to obtain pure epsilon form. For comparison, selected different published methods for recrystallization of HNIW to obtain the epsilon form were studied. All the selected methods are based on solvent-antisolvent technique. The optimum parameters, such as type of solvent and anti-solvent, volume ratio of solvent to anti-solvent, rate of addition, speed of stirring, etc., were applied to enhance the crystal size and shape of ε-HNIW. Checking the polymorphs of the obtained HNIW was done by Fourier transform infrared spectroscopy (FTIR). The thermal stability of the prepared samples was studied by using differential thermal analysis technique (DTA). Qualitative analysis of the crystal size and shape was done using scanning electron microscope (SEM) devise. Quantitative measurement of the crystals sizes for the studied samples was determined by Laser scattering particle size distribution analyzer. Impact sensitivity was measured by falling hammer test. The results indicate that all the applied methods of recrystallization give ε-HNIW. The impact sensitivity of HNIW decreases by obtaining small particles with regular shape. All the used published methods produce ε-HNIW with higher impact sensitivity than other nitramines. While the obtained crystals from the new method has regular smooth surface, with small particle size and its impact sensitivity is lower than RDX and HMX.
Źródło:
Central European Journal of Energetic Materials; 2011, 8, 3; 173-182
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Guanylurea Dinitramide (GUDN) on the Thermal Behaviour, Sensitivity and Ballistic Properties of the B-KNO3-PEC Ignition System
Autorzy:
Badgujar, D. M.
Phatak, S.
Wagh, R. M.
Bhingarakar, V.
Talawar, M. B.
Kakade, S. D.
Powiązania:
https://bibliotekanauki.pl/articles/358215.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ballistics
guanylurea dinitramide
igniter
sensitivity
thermal analysis
Opis:
Boron and potassium nitrate are the key components for the ignition system of the igniter composition for rocket propellants. Boron-potassium nitrate-ethyl cellulose (B:KNO3:PEC) in proportions of 30:70:10 is a well established igniter composition. The composition delivers a maximum pressure in the range 4.0-4.6 MPa in closed vessel firing at a loading density of 0.01 g/cm3. For the effective ignition of a large booster stage propellant (length more than 4 m), an enhancement in the maximum pressure, without affecting safety, is a prime requirement. The use of guanylurea dinitramide (GUDN) in an igniter composition has not been reported in the literature. Hence, the present study on the effect of GUDN on the combustion behaviour and sensitivity of the B/KNO3 composition (30/70) has been carried out. Several compositions containing different weight percents of GUDN were prepared. Their thermal behaviour was determined by thermal analysis DSC-TGA. Their sensitivities to external stimuli such as impact, friction and spark were evaluated. The results of closed vessel firings indicated that GUDN-based igniter compositions produced higher peak pressures (up to 4.5 MPa to 5.8 MPa), with invariably lower burning times, compared to the control composition. The REAL computer programme indicated an increase in the flame temperature of the composition from 2238 K to 2425 K on addition of GUDN. All of the compositions were insensitive towards friction up to 36 kg, and towards spark up to 5 J energy.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 315-326
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of polar plasticizers on the characteristics of selected cyclic nitramines
Autorzy:
Elbeih, A.
Zeman, S.
Pachman, J.
Powiązania:
https://bibliotekanauki.pl/articles/358627.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic materials
polymers
sensitivity
combustion
thermal stability
Opis:
Dioctyl sebacate (DOS) is a plasticizer used with oily material for the softening of polyisobutylene binder (PIB) to form a polymeric matrix. This matrix was used for the preparation of various plastic explosives. The following energetic cyclic nitramines were used as explosive fillers: BCHMX (cis-1,3,4,6- tetranitrooctahydroimidazo [4,5 d]imidazole), ε-HNIW (ε-2,4,6,8,10,12- hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane), RDX (1,3,5-trinitro-1,3,5- triazacyclohexane), and HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane). For comparison, Fluorel binder was used for the preparation of several plastic bonded explosives (PBXs) based on the same selected explosives. Impact and friction sensitivities of the prepared samples and the pure explosive fillers were measured. The thermal stability was studied using differential thermal analysis (DTA). High performance liquid chromatography (HPLC) was used to detect the presence of BCHMX dissolved in dioctyl sebacate (DOS). The heat of combustion of the prepared samples and of the pure explosive fillers was measured using a bomb calorimetry. The results show that PIB softened by plasticizer (DOS) has a greater positive effect on decreasing the impact sensitivity of the studied pure explosives than Fluorel binder. On the other hand, the plasticizer acts as a solvent for the energetic materials and decreases the decomposition temperature of these plastic explosives.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 3; 339-349
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Thermally-stable Insensitive High Explosive:N,N′-Bis(1,2,3,4-tetrazol-5-yl)-4,4′-diamino-2,2′,3,3′,5,5′,6,6′-octanitroazobenzene (BTeDAONAB)
Autorzy:
Mousavi, S.
Esmaeilpour, K.
Keshavarz, M. H.
Powiązania:
https://bibliotekanauki.pl/articles/951499.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
synthesis
BTeDAONAB
sensitivity
thermal stability
high explosive
Opis:
A novel high performance explosive compound, N,N′-bis(1,2,3,4-tetrazol5-yl)-4,4′-diamino-2,2′,3,3′,5,5′,6,6′-octanitroazobenzene( BTeDAONAB), is introduced which is a thermally stable, insensitive high explosive. The presence of −NH2, −N=N− groups and the tetrazole ring simultaneously in the BTeDAONAB unit surprisingly increases its thermal stability. For the identification and characterization of BTeDAONAB, different analytical techniques have been used, including melting point, IR, 1H NMR, 13C NMR spectroscopy, elemental analysis, differential thermal analysis (DTA), thermogravimetry (TG), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The sensitivity and detonation properties of BTeDAONAB were compared with 2,4,6-triamino1,3,5-trinitrobenzene (TATB) and N,N′-bis(1,2,4-triazol-3-yl-)-4,4′-diamino2,2′,3,3′,5,5′,6,6′-octanitroazobenzene (BTDAONAB), two well-known, thermally stable, insensitive high explosives, as well as hexanitrostilbene (HNS). These studies show that BTeDAONAB has favorable thermal stability with high performance.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 455-465
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Insensitive Booster Explosive: DAAF Surface-coated with Viton A
Autorzy:
Li, X.
Wu, B.
Liu, S.
An, C.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358841.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
DAAF
refinement
surface-coated
thermal analysis
impact sensitivity
Opis:
3,3’-Diamino-4,4’-azoxyfurazan (DAAF) is the principal component of an insensitive booster explosive; refined DAAF and DAAF surface-coated with Viton A were prepared. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to characterize the morphology, composition, and thermal decomposition of these samples. The impact sensitivity and theoretical detonation velocity of DAAF-based composites were also measured and analyzed. The results showed that DAAF surface-coated with Viton A was successfully obtained, and the impact sensitivity of DAAF/Viton A composites was much lower than that of crude DAAF. In addition, DAAF/Viton A composites exhibited better thermal stability compared to crude DAAF and refined DAAF. The theoretical detonation velocity of DAAF/Viton A composites and TATB/Viton A composites are roughly the same. Therefore, there is still great potential for DAAF to be used as the main explosive component of a booster explosive.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 445-455
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of the specific heat and thermal conductivity values on pore pressure and temperature distribution within embankment
Autorzy:
Franczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/114543.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sensitivity analysis
thermal 2D numerical modeling
embankment
FLAC
ISMOP
Opis:
The paper presents the results of the sensitivity analysis of the variability of thermal conductivity and specific heat values on temperature field and pore pressure distribution during the flooding process simulation. The sensitivity analysis was carried out using data obtained from numerical modellings. During numerical modellings the simulation of flooding process included flooding and discharging the tank, with maximum water level equal to 3.0 m was performed. 2D model was realized using Fast Lagrangian Analysis of Continua (FLAC) 7.0 software, which is a two-dimensional explicit finite difference program for engineering mechanics computation. The results presented in this paper show that the sensitivity analysis method is powerful technique that can be used in detection of area within the embankment where the biggest impact on variability of thermal conductivity are presented. It may be helpful in selecting the best area for pore pressure and temperature sensors location.
Źródło:
Measurement Automation Monitoring; 2017, 63, 3; 86-89
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of Desensitized ?-HNIW in Solvent-Antisolvent Recrystallizations
Autorzy:
Jiang, X.
Guo, X.
Ren, H.
Jiao, Q.
Powiązania:
https://bibliotekanauki.pl/articles/358201.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ε -HNIW
supersaturation
crystal morphology
thermal decomposition
reduced sensitivity
Opis:
The solubility of hexanitrohexaazaisowurtzitane (HNIW) in solvent and solvent-antisolvent mixtures, and the temperature at which the HNIW's polymorph transforms were studied. The solubility of HNIW in solvent-antisolvent mixtures was measured at 30 C and these data were fitted to a generalized solubility curve. Recrystallization experiments were conducted at 30 C in the case of saturation with the volume ratio of ethyl acetate to petroleum ether (chloroform) ranging from 0:1 to 4:1. Desensitized HNIW was obtained by ethyl acetate and petroleum ether crystallization and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), High Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM). The FTIR and XRD spectra confirmed the structural features of ε-HNIW. The blocklike ε-HNIW grains had an average particle size of 160 ?m and high purity (98.52%). The decomposition of ε-HNIW was observed in the temperature range of 225-246 C by Differential Scanning Calorimetry (DSC). Furthermore, the impact and friction sensitivity tests suggested that the desensitized ε-HNIW was less sensitive than raw HNIW. Small scale gap tests with desensitized ε-HNIW showed that these crystals are less sensitive to shock initiation.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 3; 219-236
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Advantages and Shortcomings of Using Nano-sized Energetic Materials
Autorzy:
Zohari, N.
Keshavarz, M. H.
Seyedsadjadi, S. A.
Powiązania:
https://bibliotekanauki.pl/articles/358244.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic compounds
nanosized particles
sensitivity
burn
rate
thermal stability
Opis:
Energetic materials are substances that can store chemical energy in their chemical bonds. An ideal energetic material is a substance with high performance, safety and shelf life. Many recent researches have concentrated on the synthesis or the development of new energetic materials with optimized properties, such as thermal stability, sensitivity and burn rate. The reduction of the particle size of energetic materials from micron to nano-sized is one of the suitable approaches for obtaining desirable properties. Recent progress on the reduction of the particle size of energetic materials is reviewed in this work. The effects of nano-sized particles on the performance of energetic compounds are also investigated.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 1; 135-147
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of CL-20/EPDM by a Crystal Refinement and Spray Drying Method
Autorzy:
Ji, W.
Li, X.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/358349.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
CL-20/EPDM
spray drying
impact sensitivity
thermal stability
Opis:
A 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) based mixed explosive was prepared by a spray drying method using CL-20 suspended in hexane containing EPDM rubber (ethylene-propylene-diene monomer), and made into a stable suspension. The samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their thermal stability and impact sensitivity were also measured. The results showed that the ethylene-propylene-diene-monomer rubber (EPDM) can be successfully coated on to the CL-20 crystal surface. Compared to refinement-spray CL-20, the impact sensitivity of CL-20/EPDM was significantly reduced. The characteristic drop height was increased from 28.12 to 39.78 cm. The thermal stability was better than refinement-spray CL-20.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 4; 831-840
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Analysis and Sensitivity Studies on Guanylurea Dinitramide (GUDN or FOX-12) Based Melt Cast Explosive Formulations
Autorzy:
Badgujar, D.
Talawar, M.
Powiązania:
https://bibliotekanauki.pl/articles/358782.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
guanylurea dinitramide
FOX-12
insensitive explosive
sensitivity
thermal analysis
Opis:
Guanylurea dinitramide (GUDN or FOX-12) is a stable salt of dinitramidic acid with good thermal stability, and is a good candidate for insensitive formulations. Thermal analysis reveals the compatibility of GUDN with benchmark explosives such as RDX and TNT in melt cast explosive formulations. The paper describes a thermal and sensitivity study of GUDN with RDX and TNT. In the present study GUDN was evaluated as a possible replacement for RDX/TNT based aluminized and non aluminized melt cast explosive formulations. The thermal properties of the composition were investigated as well as its sensitivity to impact and friction. Its thermal decomposition behavior was compared to a control composition based on RDX and TNT. The thermal and sensitivity results proved the worth of these compositions for melt cast explosive applications.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 2; 296-303
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of ‘Monika’ Cucumis sativus seedlings to low temperature and induction of chilling tolerance
Autorzy:
Górnik, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2199620.pdf
Data publikacji:
2015-06-20
Wydawca:
Instytut Hodowli i Aklimatyzacji Roślin
Tematy:
chilling sensitivity
cucumber
thermal shock
temperature stress
chilling resistance
Opis:
The aim of the research was to investigate the chilling sensitivity of cucumber seedlings and to alleviate its negative effects by short-term shock temperature applied during seeds imbibition, before radicle protrusion. The chilling sensitivity was investigated depending on initial root length (1, 3, 5 and 7 mm) and duration of chilling exposure (0, 1, 3, 7, 14, 21 days) at 0˘C and was evaluated by measurements of roots and hypocotyls growth, electrolyte leakage and dehydrogenases activity. To assess whether short-term shock temperature applied before radicle protrusion can increase chilling tolerance in cucumber seedlings the seeds were imbibed at 25°C for 16 h, exposed to temperatures of 0; 2,5; 5; 35; 40, 45°C for 0; 0,5; 1; 2; 4 h. The obtained results indicated that cucumber seedlings sensitivity depended on duration of chilling exposure and initial root length during which the seedlings were subjected to these conditions. Chilling sensitivity were manifested by drop in the roots and hypocotyls elongation, reduction in dehydrogenases activity and membrane integrity expressed by electrolyte leakage. Seedlings with 1 mm roots was relatively tolerant to 3 days of chilling at 0°C. Their chilling sensitivity increased as roots elongated. Seedling with 3, 5, 7 mm of roots subjected to chilling suffered a subsequent 71, 75 and 81% of growth inhibition, respectively. The presented results showed that a short-term of low (0; 2,5 or 5°C) or high (35; 40 or 45°C) temperature treatments applied before radicle protrusion i.e. after 16 h of seeds imbibition significantly counteracted the negative effects of chilling on seedlings. The best results expressed by increased length and the number of roots were obtained when imbibed seeds were exposed to 45°C for 2 and 4 h. The increased chilling tolerance of cucumber seedlings induced as early as at the stage of seed imbibition, before radicle protrusion indicates on the possibility of application of this method in practice. The positive response of such treatment on cucumber chilling tolerance are discussed.
Źródło:
Plant Breeding and Seed Science; 2015, 71; 3-11
1429-3862
2083-599X
Pojawia się w:
Plant Breeding and Seed Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
N-N Bond Lengths and Initiation Reactivity of Nitramines
Autorzy:
Zeman, Svatopluk
Atalar, Taner
Růžička, Aleš
Powiązania:
https://bibliotekanauki.pl/articles/358441.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
bond length
impact sensitivity
nitramines
reactivity
thermal decomposition
X-ray analysis
Opis:
For the 16 selected nitramines, it is shown that an increase in the energy content of these molecules (represented by enthalpies of formation) is connected with an increase in the lengths of the longest N–N bonds in the molecules. These lengths are directly proportional to the activation energies of the low-temperature thermal decomposition of the pure nitramines in all states of matter for this reaction. Raising the energy content also leads to reductions in the rate constants of thermal decomposition. Both of these facts are in contrast to expectations and also with similar published findings concerning thermal decomposition of nitramines in solution, which can be explained by the solvation effect and termination of the emerging aza-radicals in solutions. The calculated dissociation energies of the weakest N–N bonds yielded a relatively good reciprocal conformity with the lengths of the longest N–N bonds of the nitramines studied, especially when using the UB3LYP/6-31G* method. The relationship between the impact sensitivity of these nitramines and the lengths of their longest N–N bond is not completely clear. Such lengths cannot be a measure of impact reactivity, because the longest N–N bond might be stabilized in some cases by suitable intermolecular interactions with adjacent molecules in the crystal lattice.
Źródło:
Central European Journal of Energetic Materials; 2020, 17, 2; 169-200
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of CL-20 Based Composites by Compressed Air Spray Evaporation
Autorzy:
Xu, Wen Zheng
Peng, Jin Yu
Wang, Jie
Li, Hao
Wang, Jing Yu
Powiązania:
https://bibliotekanauki.pl/articles/358401.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
CL-20
CL-20-based composites
thermal stability
mechanical sensitivity
Opis:
Ultrafine CL-20 particles and three CL-20-based composites were prepared by a compressed air spray evaporation method. All samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and mechanical sensitivity instruments. The results indicated that the thermal stabilities of the CL-20-based composites are better than that of ultrafine CL-20, and that the mechanical sensitivities of ultrafine CL-20 is lower than those of CL-20-based composites. The thermal stability and safety properties of CL-20/Estane 5703 are better than the other samples.
Źródło:
Central European Journal of Energetic Materials; 2020, 17, 1; 66-84
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of microwave radiometers with square - law and linear detectors
Autorzy:
Stec, B.
Dobrowolski, A.
Susek, W.
Powiązania:
https://bibliotekanauki.pl/articles/308204.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
termografia mikrofalowa
radiometr
promieniowanie termiczne
microwave thermograph
radiometer
thermal radiation
sensitivity
Opis:
Stochastic analysis of modulation microwave radiometers with square - law and linear detectors is presented in the paper. Assuming ideal detector characteristics it is shown that in typical applications, i.e., in very low power measurements, a type of detector used is of no influence on total radiometer sensitivity. Other aspects of use of a particular detector are also presented.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 1; 112-116
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental characterisation and modelling of the thermo-viscoplastic behaviour of steel AISI 304 within wide ranges of strain rate at room temperature
Modelowanie i doświadczalna weryfikacja termo-lepkosprężystych właściwości stali AISI 304 w szerokim zakresie prędkości odkształceń w temperaturze pokojowej
Autorzy:
Rusinek, A.
Rodriguez-Martinez, J. A.
Pesci, R.
Capelle, J.
Powiązania:
https://bibliotekanauki.pl/articles/280611.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
steel AISI 304
strain rate sensitivity
extended RK model
constitutive relation
thermal imaging
Opis:
In this investigation, thermo-viscoplastic behaviour of austenitic steel AISI 304 has been characterised in tension under wide ranges of strain rate at room temperature. This metal possesses an elevated strain hardening rate and ductility which enhance its capability for absorbing energy under mechanical loading. It has been observed that the rate sensitivity of the material is independent of plastic strain. Moreover, it has been noticed that beyond a certain level of loading rate the flow stress of the material sharply increases. In agreement with experimental evidences reported in the literature, this behaviour is assumed to be caused by the drag deformation mode taking place at high strain rates. Based on such considerations, the thermo-viscoplastic behaviour of the material has been macroscopically modelled by means of the extended Rusinek-Klepaczko model to viscous drag effects. Satisfactory matching has been found between the experiments and analytical predictions provided by the constitutive relation.
W pracy scharakteryzowano termo-lepkosprężyste właściwości stali AISI 304 na podstawie prób rozciągania dla szerokiego zakresu prędkości odkształceń w temperaturze pokojowej. Stal ta posiada podwyższoną ciągliwość i stopień umocnienia odkształceniowego, które to cechy powiększają jej zdolność do pochłaniania energii mechanicznej. Zaobserwowano, że wrażliwość stali na tempo obciążeń jest niezależna od wartości odkształceń plastycznych. Co więcej, zauważono, że powyżej pewnej prędkości zmian obciążenia naprężenie płynięcia materiału gwałtownie rośnie. W zgodzie z rezultatami badań doświadczalnych opisanymi w literaturze założono, że zachowanie takie wywołane jest pojawieniem się tłumionej postaci deformacji charakterystycznej dla wysokich prędkości odkształcenia. Na podstawie przeprowadzonych badań zaproponowano makroskopowy model termo-lepkosprężystych właściwości stali w oparciu o rozszerzony model Rusinka-Klepaczki dla odzwierciedlenia efektu oporu wiskotycznego. Otrzymano zadawalającą korelację pomiędzy wynikami uzyskanymi z konstytutywnego modelu materiału oraz rezultatami badań doświadczalnych.
Źródło:
Journal of Theoretical and Applied Mechanics; 2010, 48, 4; 1027-1042
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of Four Energetic Transition Metal Complexes of 3,4-Diamino-1,2,4-triazole
Autorzy:
Yin, X.
Jin, X.
Xu, C.-X.
He, P.
Wang, K.
Zhang, J.-G.
Powiązania:
https://bibliotekanauki.pl/articles/358716.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
3,4-diamino-1,2,4-triazole
theoretic study
crystal structure
thermal stability
sensitivity
Opis:
Four complexes with the formula of [M5(DATr)12~14(H2O)6](ClO4)10 (M = Mn (1), Co (2), Ni (3), Zn (4)) about their synthesis, structures and some energetic properties (such as sensitivities tests) have been described, where the DATr here denotes 3,4-diamino-1,2,4-triazole. These four compounds are all light metallic complexes with good thermal stability. The structures of 2-4 were determined by single-crystal X-ray diffraction, and the crystal structures mainly consist of penta-nuclear units. All the structures have a common interesting property in which DATr plays a role of bi-dentate ligand. Besides, it is observed from the crystal structure of 4 that DATr can be also act as a mono-dentate ligand. Thermodynamic studies of their decomposition properties and kinetic parameters show that the four complexes have high thermal stabilities. Furthermore, tests of their impact and friction sensitivities show that complexes (2) and (3) can be potential candidates as primary explosives to replace toxic lead azide.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 301-320
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Different Ignition Responses of Powdery and Bulky 1,3,5-Triamino-2,4,6-trinitrobenzene (TATB) Based Polymer-bonded Explosives under Ultra-high Voltage Electrostatic Discharge
Autorzy:
Lyu, Z.
Long, X.
Li, Z.
Dai, X.
Deng, C.
He, S.
Li, M.
Yao, K.
Wen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358240.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
electrostatic spark sensitivity
ultra-high voltage electrostatic discharge
thermal effect
electric field effect
Opis:
The electric spark induced ignition mechanism for explosives needs further study. The ignition of powdery and bulky TATB by electrostatic discharge (ESD) was investigated. Up to 200 kV ultra-high voltage ESD was applied to powdery and bulky explosives of two TATB-based polymer-bonded explosives (named PBX-1 and PBX-2). The results showed that the spark sensitivities of powdery and bulky explosives are extremely different for the same formulation. The 50% ignition voltages of powdery PBX-1 and PBX-2 were 10.8 kV and 8.5 kV, respectively, while the values for the bulky samples (tablets) were not less than 200 kV. Both heat and the electric field can be transmitted into the powdery samples, on the other hand only the electric field can be transmitted into the bulk samples. The electric field has a smaller contribution while the heat has a larger contribution to the ignition during an ESD, i.e., the thermal effect plays a main role in the ignition process. Our experimental results are in good agreement with recent results calculated by density functional theory.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 283-298
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of thermal neutron detection capability of a CdZnTe detector in a mixed gamma-neutron radiation field
Autorzy:
Yücel, H.
Narttürk, R. B.
Zümrüt, S.
Gedik, G.
Karadag, M.
Powiązania:
https://bibliotekanauki.pl/articles/146914.pdf
Data publikacji:
2018
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron detection
CdZnTe
prompt gamma ray
thermal neutron
cadmium
neutron sensitivity
241Am-Be source
Opis:
The aim of this study was to investigate the thermal neutron measurement capability of a CdZnTe detector irradiated in a mixed gamma-neutron radiation fi eld. A CdZnTe detector was irradiated in one of the irradiation tubes of a 241Am-Be source unit to determine the sensitivity factors of the detector in terms of peak count rate (counts per second [cps]) per neutron flux (in square centimeters per second) [cps/neutron•cm–2•s–1]. The CdZnTe detector was covered in a 1-mm-thick cadmium (Cd) cylindrical box to completely absorb incoming thermal neutrons via 113Cd(n,γ) capture reactions. To achieve, this Cd-covered CdZnTe detector was placed in a well-thermalized neutron fi eld (f-ratio = 50.9 ± 1.3) in the irradiation tube of the 241Am-Be neutron source. The gamma-ray spectra were acquired, and the most intense gamma-ray peak at 558 keV (0.74 γ/n) was evaluated to estimate the thermal neutron fl ux. The epithermal component was also estimated from the bare CdZnTe detector irradiation because the epithermal neutron cutoff energy is about 0.55 eV at the 1-mm-thick Cd filter. A high-density polyethylene moderating cylinder box can also be fi tted into the Cd fi lter box to enhance thermal sensitivity because of moderation of the epithermal neutron component. Neutron detection sensitivity was determined from the measured count rates from the 558 keV photopeak, using the measured neutron fluxes at different irradiation positions. The results indicate that the CdZnTe detector can serve as a neutron detector in mixed gamma-neutron radiation fields, such as reactors, neutron generators, linear accelerators, and isotopic neutron sources. New thermal neutron filters, such as Gd and Tb foils, can be tested instead of the Cd filter due to its serious gamma-shielding effect.
Źródło:
Nukleonika; 2018, 63, 3; 59-64
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green Fabrication of Nanoscale Energetic Molecular Perovskite (H2dabco)[Na(ClO4)3] with Reduced Mechanical Sensitivity
Autorzy:
Hu, Li-shuang
Du, Zelin
Liu, Yang
Gong, Shida
Guang, Chunyu
Li, Xin
Yang, Zhi
Jia, Qi
Liang, Kaili
Powiązania:
https://bibliotekanauki.pl/articles/27787996.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
molecular perovskite
(H2dabco)[Na(ClO4)3]
ball milling
thermal decomposition
mechanical sensitivity
Opis:
High-energy-density molecular perovskite energetic materials with high detonation performance have attracted much attention, but poor safety performance has limited their potential applications. In this paper, nano sodium perchlorate-based molecular perovskite (H2dabco)[Na(ClO4)3] (nano DAP-1) was fabricated by green ball-milling technology. The structure and morphology of the samples were characterized and the results showed that nano DAP-1 with nearly spherical morphology has a narrow particle size distribution, < 1 μm. The thermal decomposition properties were investigated by differential scanning calorimetry (DSC). The exothermic peak of nano DAP-1 thermal decomposition was 330.0 °C, a decrease of 51.7 °C compared with that of raw DAP (381.7 °C). The apparent activation energy (Ea) of nano DAP-1 was calculated to be 160.9 kJ·mol–1, which is lower than that of raw DAP-1 (168.6 kJ·mol–1). Mechanical sensitivity studies showed that nano DAP-1 (H50: 64 cm) exhibited a lower impact sensitivity than that of the raw DAP-1 (H50: 51 cm). This work provides a simple and effective way for improving the thermal decomposition properties and safety performance of molecular perovskite energetic materials.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 369--384
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GAP/DNTF Based PBX Explosives: a Novel Formula Used in Small Sized Explosive Circuits
Autorzy:
An, C.
Wen, X.
Wang, J.
Wu, B.
Powiązania:
https://bibliotekanauki.pl/articles/358581.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
explosive circuits
GAP/DNTF based PBX explosives
thermal stability
mechanical sensitivity
propagation reliability
detonation velocity
Opis:
With 3,4-dinitrofurazanofuroxan (DNTF) and glycidyl azide polymer (GAP) as the main explosive and binder respectively, GAP/DNTF based PBX explosives were designed, prepared and used to fill the small groove of some explosive circuits. The formulation was: DNTF 85 wt.%, GAP 11 wt.%, 2,4-toluene diisocyanate (TDI) and other additives making up the final 4 wt.%. After the uncured slurry mixture was prepared by uniform mixing, a squeezing device was used to charge the circuit groove (dimensions less than 1 mm × 1 mm). Scanning electron microscope (SEM) results showed a fine charging effect. Differential Scanning Calorimetry (DSC) was used to determine the energy of activation (Ea) and the pre-factor (A) of GAP/DNTF and these were compared with those for raw DNTF. The influences and causes of it have been investigated. The experimental results for propagation reliability showed that when the dimensions of the linear groove were 0.8 mm × 0.8 mm, 0.7 mm × 0.7 mm, 0.6 mm × 0.6 mm or 0.5 mm × 0.5 mm, GAP/DNTF based PBX explosives can propagate explosion successfully. Furthermore, the H50 and friction sensitivity of GAP/DNTF based PBX explosives were obtained using the following mechanical sensitivity experiments. These properties are vital if GAP/DNTF based PBX explosives are to be applied in complex explosive circuits.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 397-410
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PVA hydrogel deformation in response to change in temperature or pH
Autorzy:
Kazimierska-Drobny, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/2173595.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PVA
hydrogels
non-contact method
thermal deformation
pH sensitivity
hydrożel
metoda bezkontaktowa
odkształcenie termiczne
wrażliwość na pH
Opis:
Biocompatibility, biodegradability and non-toxicity are the main attributes of any material to be used in biomedical applications. Among all the potential stimuli, pH, salt and temperature exist naturally in the internal environment of the human body. Hence internal stimuli responsive hydrogels can be exploited for specific drug delivery and tissue replacement. Poly(vinyl alcohol) (PVA) is the world’s largest volume synthetic polymer, produced for its excellent chemical resistance, physical properties and complete biodegradability, which has resulted in broad practical applications. PVA could be considered a suitable host material due to its good thermo-stability, chemical resistance and film-forming ability. It is also an important material because of its large-scale applications. Novel data analysis techniques were developed to analyze the response of PVA to external stimuli, including temperature and/or pH. The presented non-contact method shows that the PVA polymer gel, physically cross-linked by freezing and thawing, shrinks and swells under the influence of temperature, which is a reversible phenomenon. Under the given conditions, such as temperature, pH and mechanical load, the dominant factor affecting the swelling or contraction of the hydrogel is the change in the temperature of the liquid in which the PVA hydrogel sample is immersed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 2; art. no. e136724
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PVA hydrogel deformation in response to change in temperature or pH
Autorzy:
Kazimierska-Drobny, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/2090717.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PVA
hydrogels
non-contact method
thermal deformation
pH sensitivity
hydrożel
metoda bezkontaktowa
odkształcenie termiczne
wrażliwość na pH
Opis:
Biocompatibility, biodegradability and non-toxicity are the main attributes of any material to be used in biomedical applications. Among all the potential stimuli, pH, salt and temperature exist naturally in the internal environment of the human body. Hence internal stimuli responsive hydrogels can be exploited for specific drug delivery and tissue replacement. Poly(vinyl alcohol) (PVA) is the world’s largest volume synthetic polymer, produced for its excellent chemical resistance, physical properties and complete biodegradability, which has resulted in broad practical applications. PVA could be considered a suitable host material due to its good thermo-stability, chemical resistance and film-forming ability. It is also an important material because of its large-scale applications. Novel data analysis techniques were developed to analyze the response of PVA to external stimuli, including temperature and/or pH. The presented non-contact method shows that the PVA polymer gel, physically cross-linked by freezing and thawing, shrinks and swells under the influence of temperature, which is a reversible phenomenon. Under the given conditions, such as temperature, pH and mechanical load, the dominant factor affecting the swelling or contraction of the hydrogel is the change in the temperature of the liquid in which the PVA hydrogel sample is immersed.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 2; e136724, 1--7
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Molecular Perovskite (H2dabco)[NH4(ClO4)3]/Carbon Nanotubes Energetic Composite
Autorzy:
Hu, Li-shuang
Liu, Yang
He, Dan
Yang, Yajun
Gong, Shida
Guang, Chunyu
Deng, Peng
Hu, Shuangqi
Powiązania:
https://bibliotekanauki.pl/articles/27788083.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ammonium perchlorate
(H2dabco)[NH4(ClO4)3]
carbon nanotubes
mechanical sensitivity
thermal stability
Opis:
An ammonium perchlorate (AP, NH4(ClO4)3)-based molecular perovskite energetic material (H2dabco)[NH4(ClO4)3]/carbon nanotubes (DAP/CNTs) composite was prepared and characterized. Molecular perovskite DAP samples were synthesized by a facile one-pot reaction of triethylenediamine, perchloric acid (PCA, HClO4), and AP via a molecular assembly strategy. The results showed that the mechanical sensitivity (impact and friction sensitivities: >120 cm and 20%) and electrostatic spark sensitivity (8.90 J) of the DAP/CNTs energetic composite with 10 wt.% CNTs exhibited less sensitivity than that of DAP (impact, friction and electrostatic spark sensitivities: 112.3 cm, 45%, and 5.39 J, respectively), because of the mixing desensitization mechanism of CNTs. Compared with the pure DAP, the DAP/CNTs energetic composite has better performance with respect to thermal stability, exothermic capacity, and excellent continuous combustion properties. The DAP/CNTs energetic composite has potential application in a weapons system.
Źródło:
Central European Journal of Energetic Materials; 2022, 19, 1; 91--105
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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