The combustion of a B/KNO3 pyrotechnic mixture was characterized by its chemiluminescence for the first time. The reaction was initiated by a continuous wave (cw) diode laser inside a novel multipurpose reaction cell, whose design and construction are described. As in the case of the extensively studied oxidation of boron by O2, the most intense luminescence, recorded in the 400-600 nm range, is assigned to BO2. Its appearance delay time (10(-2) to 10(-1) s) equals that measured for the pressure increase and is shortened as the laser power is increased. A band observed at 355 nm appears at longer delay times than the BO2 bands. The band, and some weaker ones, may be assigned to BO, although some bands expected for BO (based on reaction between B atoms and O2) are absent from the spectra. This observation is discussed in the text, and possible emission from BN is discussed. If the band is assigned to BO, the absence of known bands may be due to specific E-V resonance energy transfer. Possible oxidation mechanisms consistent with the different delay ignition times are discussed.

[a] 1IntroductionLaser ignition of pyrotechnic mixtures offers at echnical method of physically separating ignition energy from the energetic material. This enables av iable solution to designing moderns afe-and-arm systems, which can meet higher safety standardsf or solid rocket igniters [1].Av ariety of pyrotechnic materials have beenu sed as ignition compositions in the past [2].O ft heseo nly as pecific mixture of boron and potassium nitrate( B/KNO 3 )c an be used without interruption of the pyrotechnic chain, according to MilStd1901. This is mainly due to the inherenti nsensitivity of the powder [3].H owever,n ew compositions are continually being investigated.S ome offer higher performance, and may in the future be foundt ob ea ss afe as, or even safer than B/KNO 3 .O ne example is am ixture of titanium sub hydride and potassium perchlorate with af lame temperature of about 3500 K[ 4] comparedt o 2800 Kp roducedb yB /KNO 3 .T he electro-static sensitivity of titanium sub-hydride composition has also been studied [5] and found to be less sensitivet han the NSI (NASA Standard Initiator)w hich employs ac omposition of zirconium and potassium perchlorate.Apart from ignition purposes pyrotechnic mixtures are used for several other applications, delay fuses for instance. Am ixture of borona nd barium chromate is often used for this purpose [4].I ns uch application ignitionb yl asera lso offers advantages, sucha shigher safety and reliability.In ap reviousw ork [6] an ovel experimentals etup used to characterizei gnition of ap yrotechnic pellet by laser was described. In that work only the ignition and combustion of B/KNO 3 was reported. Herewith ignition of several pyrotechnic mixtures is reported and compared in terms of ignition delay time and emission spectroscopy.T he goali st o identify any common trends which pertain to laser ignition of such pyrotechnics, and study the differences in ignition behavior.T his worki sp art of an endeavor to construct au nified modelt hat can be used to predict ignition of pyrotechnic mixtures. 2R esults and DiscussionIgnitiond elay times are af unction of laser intensity for the different mixtures are shown in Figure 1.Ignition delay times ( Figure 1) were measured using two methods. The first is by observing the pressure increase as af unction of time. The point in time at whicht he first derivative of pressure increase was higher thanathreshold of 1.5 of the noise level was considered as the ignition delay time by pressure measurement. The second method to measure ignition delay timew as by appearance of first light emission. For all mixtures both methodsy ielded similar results, apart from the B/BaCrO 4 pyrotechnic mixtures, for which no pressure increasew as detected duringc om- Abstract:I gnition of severalp yrotechnic mixtures by diode-laser was studied experimentally using an ovel combustion chamber.T he ignition delay times dependence on laser intensity could be fit by the expression t ign = aI Àn for all compositions, with I being the laser intensity at target an...

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Do humans have cognitive adaptations for detecting violations of rules in multiple moral domains? Previous research using the Wason Selection Task has provided evidence for domain-specific mechanisms for detecting violations of social exchange and hazard precaution rules. The present study investigates whether similar evidence can be found for mechanisms for detecting violations of rules relating to soliciting aid, maintaining coalitions, and navigating hierarchies. Participants (n = 887) completed one of seven Wason Selection Tasks-five sociomoral tasks (exchange, hazard, aid, coalition, and submission) and two controls (descriptive and general deontic). Participants also completed the short form Moral Foundations Questionnaire (MFQ) as a selfreport measure of five corresponding sets of moral values. The study found that, as predicted, performance on all five sociomoral tasks was significantly better than performance on the two control tasks. However, there was no relationship between task performance and corresponding moral values. These results provide initial evidence for cognitive adaptations for detecting violations of rules relating to providing aid, maintaining coalitions, and submitting to authority. We outline how future research might provide additional tests of this theory, and thereby further extend our understanding of the foundations of human sociomoral reasoning.