Head Space Solid Phase Micro-Extraction (HS - SPME) of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636)

The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME). Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm), temperature (25-60 ºC), extraction time (10-30 minutes), and sample volume (2-3 mL). The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD). The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v). In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm), temperature (23-33 ºC), pH (4.0-8.0), precursor concentration (0.02-0.1%), mannitol (0-6%), and asparagine concentration (0-0.2%) was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

Product Assurance in Agile Space Systems Development

Product assurance is an essential part of product development process if developers want to ensure that final product is safe and reliable. Product assurance can be supported withrisk management and with different failure analysis methods. Product assurance is emphasized in system development process of mission critical systems. The product assurance process in systems of this kind requires extra attention. Inthis thesis, mission critical systems are space systems and the product assurance processof these systems is presented with help of space standards. The product assurance process can be supported with agile development because agile emphasizes transparency of the process and fast response to changes. Even if the development process of space systems is highly standardized and reminds waterfall model, it is still possible to adapt agile development in space systems development. This thesisaims to support the product assurance process of space systems with agile developmentso that the final product would be as safe and reliable as possible. The main purpose of this thesis is to examine how well product assurance is performed in Finnish space organizations and how product assurance tasks and activities can besupported with agile development. The research part of this thesis is performed in survey form.