پديد آورنده :
مشكلاني، مريم
عنوان :
مطالعه ساختاري افزونهاي كلوئيدي گازي به روش هدايت اكتريكي
گرايش تحصيلي :
مهندسي شيمي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان،دانشكده مهندسي شيمي
صفحه شمار :
پانزده، 149، [II]ص: مصور، جدول، نمودار
يادداشت :
ص.ع. به فارسي و انگليسي
استاد راهنما :
محمد چالكش اميري
توصيفگر ها :
تخليه ماكروسكوپي،ميكروسكوپي , شناورسازي ميكروارگانيسم ها , دامنه كاتاليستي
تاريخ نمايه سازي :
19/01/87
استاد داور :
محسن نصر اصفهاني، محمد قريشي، بيژن نجفي، امير رحيمي،فخري سيدين آزاد
كد ايرانداك :
ID187 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رؤيت در نسخه ديجيتال
چكيده انگليسي :
AbstractColloidal Gas Aphrons CGAs are microbubbles with colloidal properties which were first introduced bySebba in 1971 The spherical bubbles are typically 10 100 m in diameter and consist of a gaseous inner coresurrounded by a thin aqueous surfactant film composed of at least two surfactant layers and an outerelectrical layer CGAs are produced by intense stirring of a surfactant solution at the speed of 6000 8000rpm This leads to entraining air and finally micro bubble formation When CGA produced volume almosttriples therefore 65 70 volume fraction of suspension consists of air This property makes CGA the thirdlightest fluids after hydrogen and helium CGAs separate easily from bulk liquid and transform into a clearsolution at the bottom and foamy suspension at the top during drainage process Due to CGA structure andsize distribution they exhibit high stability and can be transferred by Peristaltic pump to the end point ofuse Their high interfacial area makes them efficient in separation processes Several applications have beenproposed and studied for CGA like firefighting biotechnology waste treatment heavy metal removal protein recovery bioremediation flotation enhancement in mass transfer well bore drilling fluid and tissueengineering Drainage is a popular method for characterization of CGA dispersion In this technique thevariation of drained liquid volume with time is measured This measurements results in a drainage curvemainly composed of two distinct stages The first stage accounts for removal of more than 90 of bulkliquid The second stage through which foam films gradually rupture and bubbles collapse is slow due tocapillary pressure control and plateau border suction The deficiency of this method is that although thesecond stage is very time taking but it is not informative for characterization of CGA dispersion inconventional drainage measurement In this dissertation characterization and potential application of CGAshave been investigated A novel technique is proposed in this dissertation for CGA characterization usingintegrated and differentiated electrical conductivity measurements In comparison with conventional drainagemechanism differentiated EC approach depicts three stages which are initial low EC stage constant ECstage and final rising EC stage Surfactant concentration measurements have also been done and the resultssupport electrical conductivity data In addition in this work potential application of CGAs in recovery ofglucoamylase enzyme from biomass was studied Two different experimental methods were applied Cationicand anionic surfactants were tested for a pH range Integrated method revealed better separation efficiencyfor cationic surfactants
استاد راهنما :
محمد چالكش اميري
استاد داور :
محسن نصر اصفهاني، محمد قريشي، بيژن نجفي، امير رحيمي،فخري سيدين آزاد
