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Wyświetlanie 1-11 z 11
Tytuł:
Various Methods for the Determination of the Burning Rates of Solid Propellants : an Overview
Autorzy:
Gupta, G.
Jawale, L.
Mehilal, D.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/358413.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
burning rate
composite solid rocket propellant
acoustic emission system
erosive burning
Opis:
The burning rate of propellants plays a vital role among the parameters controlling the operation of solid rocket motors, therefore, it is crucial to precisely measure the burning rate in the successful design of a solid rocket motor. In the present review, a brief description of the methods for the determination of the burning rate of solid rocket propellants is presented. The effects of various parameters on the burning rate of solid propellants are discussed and reviewed. This review also assesses the merits and limitations of the existing different methods for the evaluation of the burning rate of solid rocket propellants.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 593-620
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Potassium Perchlorate as a Burning Rate Modifier in Composite Propellant Formulations
Autorzy:
Jain, S.
Mehilal, D.
Singh, P. P.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/358405.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composite propellant
burning rate
ammonium perchlorate
potassium perchlorate
Opis:
The burning rate of a solid composite propellant is one of its most important ballistic properties. To achieve a specified burning rate, transition metal oxides are used as burning rate modifiers. However, addition of transition metal oxides creates inertness in the composition. To avoid such inertness, an attempt has been made to incorporate potassium perchlorate (KP) as a burning rate modifier by partially replacing ammonium perchlorate (AP), up to the 10% level, and the composition was then studied in detail for its mechanical, thermal and ballistic properties. The data revealed that no change occurred in the case of the mechanical properties, however, the thermal stability decreased as the KP content was increased. The burning rate data revealed that on incorporation of 10% KP, there was an enhancement in the burning rate of up to 35% in comparison to the original composite propellant formulation, but beyond this no enhancement in burning rate was observed, indicating that the optimum content for KP in the composition had been reached.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 1; 231-245
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a Composite Propellant Formulation with a High Performance Index Using a Pressure Casting Technique
Autorzy:
Ramesh, K.
Jawalkar, S. N.
Sachdeva, S.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/358322.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composite propellant
high density
high performance index
pressure casting
solid loading
Opis:
There is a continuous demand for high performance composite propellant formulations to meet future requirements. The performance of composite propellant formulations can be enhanced by the addition of energetic oxidizers, like ADN/HNF as well as an energetic binder & a plasticizer. However, on incorporation of energetic ingredients, the composition becomes sensitive, and thus processing, handling and transportation pose a greater threat. Therefore, a moderately high burn rate composition having a burn rate ~ 13-14 mmźs -1 at 7000 kPa was tailored by increasing the solid loading of the propellant from 85.15% to 87.27% with the help of ammonium perchlorate and process aids without affecting the burn rate and mechanical properties. The tailored composition was studied for different properties such as end of mix viscosity, density, mechanical & ballistic properties. The evaluated data reveal that the end of mix viscosity of the tailored composition is higher than the base composition, i.e., 672 Paźs and 2340 Paźs at the same temperature; however, this viscosity was castable using a pressure casting technique. The properties of the cured propellant reveal that there is an enhancement of density from 1.74 gźcm -3 to 1.79 gźcm -3 with no other changes in mechanical properties. The performance index of the tailored composition has been increased from 416 to 437, well supported by results of ballistic evaluation motors of 2 kg.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 1; 49-58
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Twin Screw Extrusion for Continuous Processing of Energetic Materials
Autorzy:
Dombe, G.
Mehilal, D.
Bhongale, C.
Singh, P. P.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/358044.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
twin screw extruder
energetic materials
rheology
safety
residence time distribution
Opis:
Continuous processing of energetic materials using a twin screw extruder is gaining importance as it is a safe and cost-effective alternative to conventional batch processing. The continuous process based on a twin screw extruder combines the capabilities of intensive mixing and high pressure extrusion. It is used for processing a variety of energetic materials, such as gun and rocket propellants, plastic bonded explosives, pyrotechnics, thermo-baric explosives, etc. The twin screw extruder process demands various safety features for the processing of energetic materials. Therefore, exhaustive characterisation of the energetic materials in terms of safety and rheology, coupled with characterisation of the mechanical components of the extruder, are essential for designing a safe continuous process. In this article, a technological overview of continuous processing for energetic materials is presented, along with its various features, process design methodology and safety issues.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 507-522
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on High Burning Rate Composite Propellant Formulations using TATB as Pressure Index Suppressant
Autorzy:
Mehilal, -
Jawalkar, S.
Kurva, R.
Sundaramoorthy, N.
Dombe, G.
Singh, P. P.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/951502.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
composite propellant
ammonium perchlorate
TATB
pressure index suppressant
Opis:
High burning rate propellant compositions are generally used in gas generators to eject missile from canister. Because of high burning rate, pressure index of the composition increases during burning. To reduce the pressure index, a high burning rate composite propellant formulations (~20 mm/s) based on AP/HTPB/Al have been prepared by incorporating TATB and studied in detail for viscosity build-up, thermal and mechanical properties, sensitivity as well as burning rate and pressure index (n). The data indicate that there is a decrease in end of mix viscosity on increasing the percentage of TATB. The same trend was also observed with mechanical properties while significant improvement in overall thermal stability was clearly observed. The sensitivity data indicate that impact and friction values show decreasing trend infer better safe to handle. The burn rate data reveal that on addition of TATB from 0.5 to 2% decrease in burning rate was not observed while on addition of further TATB up to 5% and beyond this significant decrease in burning rate was observed. The data on pressure index (n) also reveal that TATB is very effective in reducing the 'n' value up to 2% and beyond this 'n' value increases close to standard composition. The data on 'n' value reveal that it reduces from 0.47 to that of standard composition to 0.36 for the compositions containing TATB up to 2.0% in the pressure range of 60-90 kg/cm2.
Źródło:
Central European Journal of Energetic Materials; 2012, 9, 3; 237-249
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process Optimization for the Gas-Liquid Heterogeneous Reactive Crystallization Process Involved in the Preparation of the Insensitive High Explosive TATB
Autorzy:
Nandi, A. K.
Kshirsagar, A. S.
Thanigaivelan, U.
Bhattacharyya, S. C.
Mandal, A. K.
Pandey, R. K.
Bhattacharya, B.
Powiązania:
https://bibliotekanauki.pl/articles/358228.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
TATB
TCTNB
amination
reaction crystallization
chloride impurity
particle size
Opis:
The thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6- trinitrobenzene (TATB) is manufactured by amination of 1,3,5-trichloro-2,4,6- trinitrobenzene (TCTNB) in toluene with NH3 gas. It is an isothermal, single-feed, semi-batch, gas-liquid heterogeneous, reaction crystallization process. The amination process is discussed by applying the chemical engineering methodology of mass transfer and reactive crystallization processes based on Two-Film Mass- Transfer (TFMT) theory. Kinetic expressions have been developed to define the chemical reactions as well as the physical phenomena (mass transfer) associated with this process. A single expression has been derived to explain the dependence of the ammonia consumption rate on various process parameters. Subsequently, the influence of various process parameters on the product quality (particle size and chloride impurity content) has been studied on the laboratory scale. Finally, the process has been established in the pilot plant, with optimized process conditions, to realize TATB of desired particle size and chloride content. The effects of feeding excess ammonia, and the presence of mercaptans/hydrogen sulphide impurities in poor quality toluene on the formation of certain undesirable by-products in TATB, are also discussed.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 1; 31-57
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Validated Reverse Phase HPLC Technique for the Determination of TATB Assay
Autorzy:
Bhattacharyya, S. C.
Patil, R. S.
Santosh, M. S. S. N. M.
Bhattacharya, B.
Malik, R. K.
Mehra, A.
Powiązania:
https://bibliotekanauki.pl/articles/951496.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
TATB
HPLC
HPTLC
explosive
LOQ
LOD
Opis:
The main hurdle for the estimation of the purity of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is its insolubility in most of the known organic solvents. In the conventional method, TATB is digested with steam in a modified Kjeldahl digester and the ammonia evolved is estimated quantitatively. To do away with this cumbersome method, a simple, rapid HPLC technique using a reverse phase C-18 column has been established for quantitative determination of the purity of TATB. A sharp and symmetrical peak with a retention time of 2.92 min at 355 nm is obtained for pure TATB when the flow rate is 2.0 mL/min. The linearity of the detector response has been studied with sample concentrations ranging from 10 to 50 mg/L. The method addresses two important issues of sample preparation and the precision of measurement. Unlike the previously reported HPLC techniques which mainly aimed at the detection of TATB, the present work is a validated account of a quantitative estimation of purity. Regular production batch samples have been assayed by this method and the results are compared with those obtained from the conventional analysis. The HPLC method is convenient and reliable for quality control of the product at the plant level.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 3; 641-657
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Ammonium Sulfamate Nitration for the Preparation of Ammonium Dinitramide
Autorzy:
Mandal, A. K.
Kunjir, G. M.
Singh, J.
Adhav, S. S.
Singh, S. K.
Pandey, R. K.
Bhattacharya, B.
Lakshmi Kantam, M.
Powiązania:
https://bibliotekanauki.pl/articles/358022.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Opis:
The reaction kinetics for the preparation of ammonium dinitramide (ADN) is described. ADN is the ammonium salt of the dinitramide anion, and belongs to the group of inorganic oxidizers, mainly useful for energetic rocket propellant formulations, particularly for underwater applications. It is also a potential candidate to replace ammonium perchlorate (AP), in order to develop chlorine-free, green propellants. At HEMRL, ADN is prepared by the nitration of ammonium sulfamate (AS) using mixed acid, followed by hydrolysis, neutralization with ammonia (g) and rectification using solvent. The nitration of ammonium sulfamate (AS) is carried out at a subzero temperature of -40 ±1 °C. The yield of ADN is reliant on the formation of dinitramidic acid, an intermediate product formed during the hydrolysis step, and its stability is predominantly dependent upon the level of acidity and temperature of the reaction medium. Prior to these kinetics studies, process optimization of the nitration of ammonium sulfamate (AS) was performed and gave the final mole ratio of AS:HNO3:H2SO4. Since the nitration of AS is sensitive to temperature, the rate of reaction was studied at fixed temperatures with variation of time, keeping all of the other parameters, such as vessel volume, agitator speed, feed rate etc., constant. During these studies, predetermined quantities of ammonium sulfamate (AS) and mixed acid were allowed to react at a fixed temperature (-40 ±1 °C) for different reaction periods to generate the concentration profile of AS. Using this concentration profile, the reaction order and reaction rate constant were evaluated. In order to find the effect of temperature on the reaction rate and yield, experiments were conducted at other temperatures such as -30 and -50 °C. In the present studies, it was found that the optimum temperature of nitration is -40 ±1 °C and that the rate of reaction follows a pseudo second order process with rate constant 0.01113 (min-1)•(mol/L)-1. The reaction time evaluated for 55 to 60% conversion is about 70-80 minutes at -40 ±1 °C, based on this kinetics. The activation energy of AS nitration was found to be -4.6 kcal/mol, using the reaction kinetic data based on the temperature dependent rate equation derived from Arrhenius’s law.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 1; 83-97
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cooperation of multiple autonomous robots and analysis of their swarm behawior
Współpraca roju autonomicznych robotów i analiza ich zbiorowych zachowań
Autorzy:
Czejdo, B.
Daszczuk, W. B.
Grabski, W.
Bhattacharya, S.
Powiązania:
https://bibliotekanauki.pl/articles/316981.pdf
Data publikacji:
2018
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
autonomous robots
behavior verification
model checking
integrated model of distributed systems
deadlock
termination
autonomiczne roboty
weryfikacja zachowań
weryfikacja modelowa
zintegrowany model systemów rozproszonych
zakleszczenie
terminacja
Opis:
In this paper, we extended previous studies of cooperating autonomous robots to include situations when environmental changes and changes in the number of robots in the swarm can affect the efficiency to execute tasks assigned to the swarm of robots. We have presented a novel approach based on partition of the robot behavior. The sub-diagrams describing sub-routs allowed us to model advanced interactions between autonomous robots using limited number of state combinations avoiding combinatorial explosion of reachability. We identified the systems for which we can ensure the correctness of robots interactions. New techniques were presented to verify and analyze combined robots’ behavior. The partitioned diagrams allowed us to model advanced interactions between autonomous robots and detect irregularities such as deadlocks, lack of termination etc. The techniques were presented to verify and analyze combined robots’ behavior using model checking approach. The described system, Dedan verifier, is still under development. In the near future, timed and probabilistic verification are planned.
W artykule opisano kontynuację wcześniejszych badań dotyczących współpracy autonomicznych robotów wewnątrz budynku. Obejmują one obejmują sytuacje, w których zmiany środowiska i zmiana liczby robotów w roju mogą poprawić lub pogorszyć efektywność wykonywania zadań przypisanych do roju robotów. Zaprezentowaliśmy nowatorskie podejście z wykorzystaniem dzielenia zachowań robota na zachowania składowe. Poddiagramy opisujące kładowe podmarszruty pozwoliły nam modelować zaawansowane interakcje między autonomicznymi robotami w oparciu o ograniczoną liczbę kombinacji zachowań, unikając eksplozji kombinatorycznej przestrzeni osiągalności. Opisano systemy, dla których możemy zapewnić poprawność interakcji robotów i zaprezentowano techniki weryfikacji i analizy zachowań połączonych robotów. Diagramy podzielone na partycje pozwoliły nam modelować zaawansowane interakcje pomiędzy autonomicznymi robotami i wykrywać nieprawidłowości, takie jak zakleszczenia, brak terminacji itp. Przedstawiono techniki weryfikacji i analizy złożonych zachowań robotów za pomocą techniki weryfikacji modelowej. Opisany system weryfikacji, Dedan, jest wciąż rozwijany. W niedalekiej przyszłości planowana jest weryfikacja z czasem rzeczywistym i probabilistyczna.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2018, 19, 12; 872-879
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving resilience of autonomous moving platforms by real-time analysis of their cooperation
Poprawa bezpieczeństwa autonomicznych platform mobilnych drogą analizy ich współpracy w czasie rzeczywistym
Autorzy:
Czejdo, B.
Bhattacharya, S.
Baszun, M.
Daszczuk, W. B.
Powiązania:
https://bibliotekanauki.pl/articles/316013.pdf
Data publikacji:
2016
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
Autonomous Moving Platforms
safety
Dedan verifier system
autonomiczne platformy mobilne
bezpieczeństwo
system weryfikacyjny Dedan
Opis:
Environmental changes, failures, collisions or even terrorist attacks can cause serious malfunctions of the delivery systems. We have presented a novel approach improving resilience of Autonomous Moving Platforms AMPs. The approach is based on multi-level state diagrams describing environmental trigger specifications, movement actions and synchronization primitives. The upper level diagrams allowed us to model advanced interactions between autonomous AMPs and detect irregularities such as deadlocks live-locks etc. The techniques were presented to verify and analyze combined AMPs’ behaviors using model checking technique. The described system, Dedan verifier, is still under development. In the near future, a graphical form of verified system representation is planned.
Zmiany w otoczeniu, awarie, kolizje czy nawet ataki terrorystyczne mogą spowodować poważne awarie w systemach transportowych. W artykule zaprezentowaliśmy nowe podejście do poprawy odporności autonomicznych platform mobilnych (AMPs). Podejście to opiera się na specyfikacji przy pomocy wielopoziomowych diagramach stanów, opisujących wpływ otoczenia, podejmowane akcje komunikacyjne i prymitywy synchronizacyjne. Schematy na górnym poziomie pozwoliły modelować zaawansowane interakcje między autonomicznymi pojazdami i wykrywać nieprawidłowości, takie jak zakleszczenia, częściowe zakleszczenia itp. Zaprezentowano techniki zastosowane w celu weryfikacji i analizy łącznego zachowania pojazdów techniką weryfikacji modelowej. Opisany system weryfikacyjny Dedan jest wciąż w fazie rozwoju. W niedalekiej przyszłości planowana jest graficzna forma reprezentacji weryfikowanego systemu.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 6; 1294-1301
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cadmium acts as a silent killer of liver by inducing oxidative stress and hepatocellular injury and a possible amelioration by vitamin B12 and folic acid in rat model
Autorzy:
Banerjee, A.
Nandi, P.
Bhattacharya, C.
Kabir, Z.
Mukherjee, S.
Maji, B.K.
Powiązania:
https://bibliotekanauki.pl/articles/1918855.pdf
Data publikacji:
2019-08-26
Wydawca:
Uniwersytet Medyczny w Białymstoku
Tematy:
Cadmium
liver
hepatocellular injury
oxidative stress
Opis:
Purpose: To investigate the involvement of oxidative stress in Cadmium (Cd) induced alteration in the functional status of the liver. And to assess the efficacy of folic acid and vitamin B12 in preventing Cd-induced damage in the same. Materials and methods: The experiment was carried out for four weeks. For the experiment, 25 healthy male adult Wistar albino rats were randomly selected and were divided into five equal groups and treated as control, treated with Cd, supplemented with vitamin B12 and folic acid and in the combination of these two. After 28 days the liver function enzymes and oxidative stress parameters were measured. Results: Cd is the silent killer of the hepatic system through the induction of oxidative stress in male rats. From this investigation, it is evident that the folic acid+vitamin B12 possess significant hepatoprotective and antioxidant activity against Cd-induced hepatotoxicity in the rat model. In addition, results revealed that the folic acid alone and or in combination with vitamin B12 blunted the hepatotoxic effect significantly. Conclusions: Based on results obtained, it can be concluded that folic acid and vitamin B12 offer a protective effect in Cd-induced oxidative stress associated with hepatocellular injury. Folic acid and vitamin B12 can be considered as a potent natural antioxidant which has the capacity to provide protection against Cd-induced oxidative stress in the liver in rats. However, to elucidate the exact mechanism of this modulatory effect and to examine its potential therapeutic effects further studies are essential.
Źródło:
Progress in Health Sciences; 2019, 1; 105-117
2083-1617
Pojawia się w:
Progress in Health Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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