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Wyszukujesz frazę "composition B" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Design and operation of a small scale set back force simulator and its use in investigation into composition B fillings subjected to hot gun scenarios
Autorzy:
Cartwright, M.
Delany, P.
Powiązania:
https://bibliotekanauki.pl/articles/358919.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
set back simulation
composition B
hot gun defects
Opis:
Ammunition fired from large calibre gun chambers may experience accelerations in the regions of 150,000 m s-2 and as a result are subjected to considerable force during the process of set back. During firing some of the energy may be transferred to the filling and any defects present in the shell filling can lead to local hotspots which may result in premature ignition of the warhead. A potential source of defects is the application of excessive heat to the ammunition either by storage in a hot environment or accidentally by leaving the ammunition in a hot gun scenario in the chamber of the gun. A hot gun scenario can be defined as arising after 50 rounds or more have been fired in a four hour period. In this scenario the filling may easily exceed the qualification temperature with two possible accidents occurring. Cook-off of the filling can result in spontaneous firing of the round or, when correctly initiated, the round may premature in the gun barrel both of which may have catastrophic results. Currently there is no standard test to evaluate the behaviour of composition B (60% RDX: 40% TNT) filled ammunition subjected to a hot gun scenario. Because of its low melting point 80 °C the liquid TNT can separate from the RDX increasing its sensitivity and increasing the probability of an in bore premature when fired. This paper describes the design and operation of a small scale simulator for set back forces and its use to investigate the conditions under which composition B fillings, subjected to a hot gun scenario, could initiate. Samples of composition B were subjected to thermal treatments to mimic hot gun conditions and then subjected to simulated set back conditions and the level of impact energy required for initiation determined. This was compared with the level for untreated samples and a possible evaluation of current hot gun procedures undertaken. The indications are that the process can be cost effective in simulating set back induced premature ignitions.
Źródło:
Central European Journal of Energetic Materials; 2009, 6, 1; 103-117
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Degradation Behaviour and Kinetics of aged TNT-based Melt Cast Composition B
Autorzy:
Singh, Arjun
Sharma, Tirupati Chander
Singh, Vasundhara
Mukherjee, Niladri
Powiązania:
https://bibliotekanauki.pl/articles/358256.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composition B
thermal degradation
thermogravimetry
Differential Scanning Calorimetry
kinetics
thermodynamic parameters
Opis:
In the present paper, three kinds of aged and freshly prepared 2,4,6-trinitrotoluene (TNT) based Composition B stockpiled, for a period of 20 and 32 years, were investigated for the effect of natural ageing on their thermal degradation behaviour and kinetic parameters. The properties investigated indicated that there was no significant change in the thermal stability of the samples aged under natural environmental conditions. The kinetic parameters were studied by means of the Kissinger method using the peak temperature at maximum reaction rate from DSC data, and the isoconversional Kissinger-Akahira-Sunnose (KAS) and ASTM E689 methods from TGA data. The apparent activation energies calculated by the Kissinger method were 173.8 kJ·mol–1 for fresh, 170.4 kJ·mol–1 for 20 y old and 187.1 kJ·mol–1 for 32 y old Composition B, respectively. The values calculated by the KAS method were found to be in the range 77.2-235.8 kJ·mol–1 for fresh Composition B, 75.7-224.0 kJ·mol–1 for 20 y old and 70.4-196.0 kJ·mol–1 for 30 y old Composition B, respectively. The activation energies obtained from the KAS methods are in good agreement and consistent with the isoconversional ASTM E689 kinetic method. The thermodynamic parameters, such the Gibbs free energy of activation (ΔG#), activation enthalpy (ΔH#) and activation entropy (ΔS#) for the formation of activated complexes were also studied and are discussed.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 3; 360-379
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fireweed (Epilobium angustifolium L.): botany, phytochemistry and traditional uses. A review
Autorzy:
Adamczak, Artur
Dreger, Mariola
Seidler-Łożykowska, Katarzyna
Wielgus, Karolina
Powiązania:
https://bibliotekanauki.pl/articles/2048739.pdf
Data publikacji:
2019
Wydawca:
Instytut Włókien Naturalnych i Roślin Zielarskich
Tematy:
rosebay willowherb
phytochemical composition and variability
ellagitannins
oenothein B
ethnobotany
wierzbówka kiprzyca
skład i zmienność fitochemiczna
elagotaniny
oenoteina B
etnobotanika
Opis:
Fireweed (Epilobium angustifolium L., Onagraceae) is one of important medicinal plants used especially in the treatment of urogenital disorders, including benign prostatic hyperplasia (BPH) and prostatitis. The therapeutic effects of E. angustifolium extracts comprise antiproliferative, anti-inflammatory, immunomodulatory, antioxidant, and also antimicrobial activities. The aim of the present review was to provide the information on the botany, phytochemistry and traditional uses of E. angustifolium. This plant is a widespread circumboreal species of North America and Eurasia, tolerant in terms of habitat conditions, and often occupying man-made open habitats. Phytochemical studies on E. angustifolium resulted in the identification of about 250 different metabolites, including about 170 substances found for the first time in this plant in the last six years (2014–2019). Fireweed has an abundance of polyphenolic compounds, particularly ellagitannins. Oenothein B and quercetin-3-O-glucuronide are proposed as markers for the identification and standardization of the plant raw material. E. angustifolium exhibits significant phytochemical variability in relation to the geographical origin, plant part and time of harvest/vegetation phase. Survey of the ethnobotanical literature showed that the above-mentioned species has been widely used not only as a medicinal, but also as an edible, honey and decorative plant.
Źródło:
Herba Polonica; 2019, 65, 3; 51-63
0018-0599
Pojawia się w:
Herba Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Różnice między PN-88/B-06250 Beton zwykły i PN-EN 206-1:2003 Beton. Część 1: Wymagania, właściwości, produkcja i zgodność
The differences between: PN-88/B-06250 Ordinary cencrete and PN-EN 206-1:2003 Concrete - Part 1: specification performance, production and conformity
Autorzy:
Bundyra-Oracz, G.
Powiązania:
https://bibliotekanauki.pl/articles/183018.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniki Budowlanej
Tematy:
beton
skład betonu
projektowanie
właściwości
PN-88/B-06250
PN-EN 206-1:2003
wytrzymałość na ściskanie
konsystencja
trwałość
środowisko korozyjne
dodatek do betonu
specyfikacja techniczna
beton towarowy
concrete
concrete composition
designing
Polish standard
compression strength
consistency
durability
corrosive environment
concrete admixture
ready-mix concrete
Opis:
Przedstawiono różnice pomiędzy dwiema normami: PN-88/B-06250 oraz PN-EN 206-1:2003 poprzez porównanie wybranych obszarów tematycznych, które są istotne przy projektowaniu składu betonu i deklarowaniu jego właściwości. Specjalną uwagę zwrócono na szczegółowość podejścia w PN-88/B-06250 do projektowania składu betonu, co w istotnym stopniu odróżnia ten dokument od normy PN-EN 206-1. Artykuł stanowi przegląd wielu zagadnień użytecznych dla technologa i projektanta betonu.
In this paper the differences between: PN-88/B-06250 "Ordinary concrete" and PN-EN 206-1:2003 "Concrete- Part 1: Specification performance, production and conformity were presented". In report, the changes in concrete production associated with PN-EN 206-1 implementation was described.
Źródło:
Prace Instytutu Techniki Budowlanej; 2008, R. 37, nr 2, 2; 3-26
0138-0796
Pojawia się w:
Prace Instytutu Techniki Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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