FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W623980131> ?p ?o ?g. }

• W623980131 abstract "Strobes are self-sustained oscillatory combustions that have various applications in the fireworks industry and also in the military area (signaling, missile decoys and crowd control). However, most of the strobe compositions were discovered using trial and error methods. The fundamentals mechanisms involved in strobe remain unclear. A few oscillatory chemical systems were reviewed in in this thesis and compared to strobe reactions. First, the oscillatory behavior observed in some of the systems (BZ type reactions and cool flames) was explained by the presence of intermediate species that are created and consumed by two chemical pathways. They compete with each other and it results in an oscillation of the concentration of the intermediate species. Then, to explain the oscillatory behavior observed in some SHS (Self-propagating High-temperature Synthesis) combustion, the assumption made was that if the reaction time is much larger than the characteristic time of heat transfer. Those two features were considered in the analysis of strobe reaction. The classical ternary strobe composition made of ammonium perchlorate / magnalium / barium sulfate was studied in this thesis. The following physical mechanisms were observed. After ignition of the composition, there is the formation of a layer on top of the pellet. This layer is heated up by a reaction and begins to melt. When the flash is imminent, parts of the surface layer are ejected indicating the formation and rapid expansion of gas below the surface. A bright flash follows after which the process is repeated. The pellet is consumed almost linearly, layer by layer. Some of the chemical mechanisms of this strobe were identified. The decomposition of ammonium perchlorate present in the layer ignited produces the heat and the oxygen molecules necessary for the strobe reaction to proceed. Then the magnalium begin to melt and decomposes into aluminum and magnesium. Finally, the oxidation of liquid and gaseous aluminum and magnesium were observed. The same reactions occur in the next layer. Parameters that influence the strobe effect were emphasized. First, the effect of potassium dichromate was studied. A small amount of this compound in the compositions has an important impact on the regularity and sharpness of flashes. It was hypothesized that the decomposition of this compound during the dark phase absorbs part the energy released, restraining the increasing reaction rate. Then, the influence of the melting point of the metal sulfates or nitrates was studied. It appears that the compositions containing high melting point metal sulfates (barium and strontium sulfates) produce sharper and more regular flashes. Those compositions also have a slower frequency. Finally, the influence of the heat transfer of the composition on the strobe behavior by varying the fuel weight fraction and its particle size. It appears that compositions with a lower heat transfer in the composition results in a lower flash frequency. Besides, it was noticed that none of those parameters seemed to have a strong influence on the temperature of the compositions while burning" @default.
• W623980131 created "2016-06-24" @default.
• W623980131 creator A5033274090 @default.
• W623980131 date "2013-01-01" @default.
• W623980131 modified "2023-09-24" @default.
• W623980131 title "New insights into strobe reactions: An intriguing oscillatory combustion phenomenon (Nieuwe inzichten in strobe reactions: Een intrigerend oscillerend verbrandingsfenomeen)" @default.
• W623980131 hasPublicationYear "2013" @default.
• W623980131 type Work @default.
• W623980131 sameAs 623980131 @default.
• W623980131 citedByCount "0" @default.
• W623980131 crossrefType "dissertation" @default.
• W623980131 hasAuthorship W623980131A5033274090 @default.
• W623980131 hasConcept C105923489 @default.
• W623980131 hasConcept C121332964 @default.
• W623980131 hasConcept C127413603 @default.
• W623980131 hasConcept C147789679 @default.
• W623980131 hasConcept C152984320 @default.
• W623980131 hasConcept C159063594 @default.
• W623980131 hasConcept C159467904 @default.
• W623980131 hasConcept C159985019 @default.
• W623980131 hasConcept C177801218 @default.
• W623980131 hasConcept C178790620 @default.
• W623980131 hasConcept C17923525 @default.
• W623980131 hasConcept C185592680 @default.
• W623980131 hasConcept C192562407 @default.
• W623980131 hasConcept C2776704483 @default.
• W623980131 hasConcept C2779227376 @default.
• W623980131 hasConcept C42360764 @default.
• W623980131 hasConcept C97355855 @default.
• W623980131 hasConceptScore W623980131C105923489 @default.
• W623980131 hasConceptScore W623980131C121332964 @default.
• W623980131 hasConceptScore W623980131C127413603 @default.
• W623980131 hasConceptScore W623980131C147789679 @default.
• W623980131 hasConceptScore W623980131C152984320 @default.
• W623980131 hasConceptScore W623980131C159063594 @default.
• W623980131 hasConceptScore W623980131C159467904 @default.
• W623980131 hasConceptScore W623980131C159985019 @default.
• W623980131 hasConceptScore W623980131C177801218 @default.
• W623980131 hasConceptScore W623980131C178790620 @default.
• W623980131 hasConceptScore W623980131C17923525 @default.
• W623980131 hasConceptScore W623980131C185592680 @default.
• W623980131 hasConceptScore W623980131C192562407 @default.
• W623980131 hasConceptScore W623980131C2776704483 @default.
• W623980131 hasConceptScore W623980131C2779227376 @default.
• W623980131 hasConceptScore W623980131C42360764 @default.
• W623980131 hasConceptScore W623980131C97355855 @default.
• W623980131 hasLocation W6239801311 @default.
• W623980131 hasOpenAccess W623980131 @default.
• W623980131 hasPrimaryLocation W6239801311 @default.
• W623980131 hasRelatedWork W1485986331 @default.
• W623980131 hasRelatedWork W1540597317 @default.
• W623980131 hasRelatedWork W1965027249 @default.
• W623980131 hasRelatedWork W1965098475 @default.
• W623980131 hasRelatedWork W1968581338 @default.
• W623980131 hasRelatedWork W1973454450 @default.
• W623980131 hasRelatedWork W1974614065 @default.
• W623980131 hasRelatedWork W1977370139 @default.
• W623980131 hasRelatedWork W1997448892 @default.
• W623980131 hasRelatedWork W2002496840 @default.
• W623980131 hasRelatedWork W2008045996 @default.
• W623980131 hasRelatedWork W2019988387 @default.
• W623980131 hasRelatedWork W2031667444 @default.
• W623980131 hasRelatedWork W2044464293 @default.
• W623980131 hasRelatedWork W2057605668 @default.
• W623980131 hasRelatedWork W2080795002 @default.
• W623980131 hasRelatedWork W2148982964 @default.
• W623980131 hasRelatedWork W2313423925 @default.
• W623980131 hasRelatedWork W349326117 @default.
• W623980131 hasRelatedWork W291654947 @default.
• W623980131 isParatext "false" @default.
• W623980131 isRetracted "false" @default.
• W623980131 magId "623980131" @default.
• W623980131 workType "dissertation" @default.