4506

4240

كارشناسي ارشد

شيمي-فيزيك

اصفهان:دانشگاه صنعتي اصفهان.دانشكده شيمي

1387

چهارده،119 [II]ص:مصور،نمودار،جدول

ص.ع به: فارسي و انگليسي

محمود تبريزچي

محمدتقي جعفري

محمدحسين كشاورز،فرهاد حدادزاده

1396/09/12

كتابنامه

شيمي

ID4240

به فارسي و انگليسي:قابل رويت در نسخه ديجيتال

AbstractNowadays with increasing the terrorist threats it is very crucial to detect any kind ofexplosives to provide a secure protection for important places such as air ports embassies governmental buildings public and holy places power stations dams etc Many methods have been reported to be used for detection of explosives IMS has beenproved to be one of the best methods for the detection of trace level of explosives IMS may operate in two different modes positive or negative In the positive mode onlypositive ions are detected while in the negative mode the electric field is reversed tocollect the negative ions Explosives are commonly detected in the negative mode Normally an electron source is used for the ionization in the negative mode The sourceutilizes a discharge in pure nitrogen which produces electrons several orders ofmagnitude higher than that produced by the conventional 63Ni If negative coronadischarge happens in air it produces NO2 with a very high electron affinity even higherthan that of explosives and prevents ionization of those compounds Thus negativecorona discharge in air is also not appropriate for detection of explosives The aim of this work is to use the positive corona discharge which operates in air forionization of explosives This was achieved by considering the pyrolysis of explosives atelevated temperature The products of the pyrolysis contain nitrogen oxide that is wellionized in the positive corona discharge As a result explosives may be detected bymonitoring the NO peak in ion mobility spectrum Moreover each explosive showadditional peaks that may be used for identification In this thesis thermal decomposition products of several explosives includingPentaerythritol Tetranitrate PETN Cyclo 1 3 5 Trimethylene 2 4 6 Trinitramine RDX 2 4 6 Trinitrotoluene TNT 2 4 Dihydro 5 nitro 3H 1 2 4 triazol 3 one NTO 1 3 5 7 tetranitro 1 3 5 7 tetrazocine HMX has been evaluate between 150 C to 250 Cin positive polarity in air The limit of detection for RDX HMX PETN NTO and TNTwere 1 10 9 1 10 8 1 10 6 1 10 6 and 4 10 8 g Respectively In continue the newdesign has been use for improvement in NO peak detection producted of the pyrolysis ofexplosives correct structure corona discharge This design consists of a curtain plate toprevent the diffusion of NOx into the ionization region Detection of explosives has beenevaluate in air too Envuronment interference vapor and NH3 has been investigated inthis condition

محمود تبريزچي

محمدتقي جعفري

محمدحسين كشاورز،فرهاد حدادزاده