پديد آورنده :
روح الله نژاد، فرشته
عنوان :
بررسي اثر فشار بر طيف سنجي تحرك يوني و ارائه روشي جديد براي اندازه گيري ضريب نفوذ
گرايش تحصيلي :
﴿شيمي فيزيك﴾
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي
صفحه شمار :
شانزده،153،[II]ص.: مصور،جدول،شكل،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
محمودتبريزچي
توصيفگر ها :
معادله نرنست- اينشتين , راديواكتيو , پالس ژنراتور , يونيزاسيون الكترواسپري،شعله،سطحي , سل , كلكتور , كروناي منفي , روش موئينه،لوله بسته،دستگاه دوجانبي،منبع نقطه اي.... , كاتانورز , كروماتوگرافي گازي ,
استاد داور :
علي مقاري،سيدمحمدتقي المدرسي،يوسف غايب، عزت كشاورزي
كد ايرانداك :
ID134 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Abstract In this work an IMS cell has beendesignedand constructedto allow the pressureto bereduced inside the IMS cell In this cell corona dischargewas employed as the ionizationsource Reducingpressureaffected both the dischargeand the performanceof the IMS Thedischargecurrentwas observedto increasewith reducingpressurewhile the ignition potentialdecreased The ion current received at the collector plate was also increasedabout fifty timeswhen the pressurewas reduced from ambientpressureto 15 torr The higher ion current canleadto an extendeddynamicrange The effect of pressureon ion mobilities has beeninvestigatedand comparedwith that oftemperature this connection IMS spectra In were recordedat variouspressures ranging from 29torr up to atmosphericpressure The results show that IMS peaks shift perfectly linear withpressurewhich is in excellent agreement with the ion mobility theory However experimentalion mobilities versus temperatureshow deviation from the theoretical trend The deviation isattributed to formation of clusters The different behavior of pressureand temperaturewasexplained to be due to the different impact of pressureand temperature on hydration andclustering of ions Pressureaffects the clusteringreactions linearly but temperatureaffects itexponentially In addition the effect of pressureon separation factor resolving power and resolution inion mobility spectrometry beeninvestigated has IMS spectrawere recordedat various pressuresranging from 29 torr up to atmosphericpressureand various ion gatesranging from 50 225J l seconds Results show that the separationfactors remain unaffected by pressure However pressurehas stronginfluence on resolving powerand resolution Reducingpressureat constantpulse width decreases resolving power and resolution On the other hand the decreasein theresolutioncan be compensated shorteningthe ion pulse width sincereducingpressureresults byin a higher ion current In the secondpart of the thesisa methodto measure diffilsion coefficientof molecules thein gas phase by means of negative corona dischargeIMS has beenproposed In this method sampleis injectedas a shortpulse into the flowing drift gasto form a Gaussiancloud inside thedrift region The cloud is irradiated with a fast moving swarm of electronsreleasing from theshutter grid to create negative ions Then the ions drift towards the detectorwhere they arecollected The ion signal patternreflectsthe spatialdistribution of the sampleinsidethe cloud atthe time of exposure The consecutiveIMS spectrashowthe evolution of the cloud in time Thespectrafit to Gaussianfunctions and information aboutthe diffilsion coefficientsare extracted The resultsfor selectedsamples in good agreements are with the previouslyreportedvalues d f I fu o Ji i If W JI #Q
استاد راهنما :
محمودتبريزچي
استاد داور :
علي مقاري،سيدمحمدتقي المدرسي،يوسف غايب، عزت كشاورزي
